%0 Patent %A Fei, B. %A Yang, X. %A Sechopoulos, I. %T Processing method for breast computed tomography (BCT) image to determine tissue constituents of breast involves generating classified image of breast based of image processing that determines tissue constituents classifications %I Univ Emory %O Processing method for breast computed tomography (BCT) image to determine tissue constituents of breast involves generating classified image of breast based of image processing that determines tissue constituents classifications %O WO2012109643-A2; WO2012109643-A3 %O DIIDW:2012K81073 %X NOVELTY - The processing method (100) involves processing BCT image to determine first classification and second classification of tissue constituents represented by the image (150), such that the second classification is based in part on the first classification, and generating one classified image of the breast based on the processing. The first classification is based on intensity information and the second classification is based on position information. USE - Processing method for BCT image to determine tissue constituent of breast to detect and diagnose breast cancer and to identify women of high-risk. ADVANTAGE - The method enables automatic classification of high resolution BCT images into skin, fat and grandular tissue based on intensity and position information. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:(1) a computer-readable storage medium storing instructions for processing BCT image to determine tissue constituents of breast; and(2) a system for processing BCT image to determine tissue constituents of breast. DESCRIPTION Of DRAWING(S) - The drawing shows the flowchart of the method to generate classified image of breast.Processing method (100)Receiving BCT image (110)Preprocessing BCT image (120)Correcting BCT image (130)Filtering corrected image (140)Processing BCT image to determine first classification and second classification of tissue constituents represented by the image (150)Quantifying classified breast tissue image (160)Outputting classified breast tissue image (170) %O 0 %O ://DIIDW:2012K81073 %0 Journal Article %A Fei, B. W. %A Ng, W. S. %A Chauhan, S. %A Kwoh, C. K. %D 2001 %T The safety issues of medical robotics %J Reliability Engineering & System Safety %V 73 %N 2 %O Aug %P 183-192 %O The safety issues of medical robotics %O 0951-8320 %O 10.1016/s0951-8320(01)00037-0 %O WOS:000170273500008 %X In this paper, we put forward a systematic method to analyze, control and evaluate the safety issues of medical robotics. We created a safety model that consists of three axes to analyze safety factors. Software and hardware are the two material axes. The third axis is the policy that controls all phases of design, production, testing and application of the robot system. The policy was defined as hazard identification and safety insurance control (HISIC) that includes seven principles: definitions and requirements, hazard identification, safety insurance control, safety critical limits, monitoring and control, verification and validation, system log and documentation. HISIC was implemented in the development of a robot for urological applications that was known as URObot. The URObot is a universal robot with different modules adaptable for 3D ultrasound image-guided interstitial laser coagulation, radiation seed implantation, laser resection, and electrical resection of the prostate. Safety was always the key issue in the building of the robot. The HISIC strategies were adopted for safety enhancement in mechanical, electrical and software design. The initial test on URObot showed that HISIC had the potential ability to improve the safety of the system. Further safety experiments are being conducted in our laboratory. (C) 2001 Elsevier Science Ltd. All rights reserved. %O Times Cited: 18 Chauhan, Sunita/A-3814-2011; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 21 %O ://WOS:000170273500008 %0 Journal Article %A Fei, B. W. %A Wheaton, A. %A Lee, Z. H. %A Duerk, J. L. %A Wilson, D. L. %D 2002 %T Automatic MR volume registration and its evaluation for the pelvis and prostate %J Physics in Medicine and Biology %V 47 %N 5 %O Mar 7 %P 823-838 %O Automatic MR volume registration and its evaluation for the pelvis and prostate %O 0031-9155 %O 10.1088/0031-9155/47/5/309 %O WOS:000174531200009 %X A three-dimensional (3D) mutual information registration method was created and used to register MRI volumes of the pelvis and prostate. It had special features to improve robustness. First, it used a multi-resolution approach and performed registration from low to high resolution. Second, it used two similarity measures, correlation coefficient at lower resolutions and mutual information at full resolution, because of their particular advantages. Third, we created a method to avoid local minima by restarting the registration with randomly perturbed parameters. The criterion for restarting was a correlation coefficient below an empirically determined threshold. Experiments determined the accuracy of registration under conditions found in potential applications in prostate cancer diagnosis, staging, treatment and interventional MRI (iMRI) guided therapies. Images were acquired in the diagnostic (supine) and treatment position (supine with legs raised). Images were also acquired as a function of bladder filling and the time interval between imaging sessions. Overall studies on three patients and three healthy volunteers, when both volumes in a pair were obtained in the diagnostic position under comparable conditions, bony landmarks and prostate 3D centroids were aligned within 1.6 +/- 0.2 mm and 1.4 +/- 0.2 mm, respectively, values only slightly larger than a voxel. Analysis suggests that actual errors are smaller because of the uncertainty in landmark localization and prostate segmentation. Between the diagnostic and treatment positions, bony landmarks continued to register well, but prostate centroids moved towards the posterior 2.8-3.4 mm. Manual cropping to remove voxels in the legs was necessary to register these images. In conclusion, automatic, rigid body registration is probably sufficiently accurate 0 for Man. applications in prostate cancer. For potential iMRI-guided treatments, the small prostate displacement between the diagnostic and treatment positions can probably be avoided by acquiring volumes in similar positions and by reducing bladder and rectal volumes. %O Times Cited: 54 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 58 %O ://WOS:000174531200009 %0 Journal Article %A Fei, B. W. %A Duerk, J. L. %A Boll, D. T. %A Lewin, J. S. %A Wilson, D. L. %D 2003 %T Slice-to-volume registration and its potential application to interventional MRI-guided radio-frequency thermal ablation of prostate cancer %J Ieee Transactions on Medical Imaging %V 22 %N 4 %O Apr %P 515-525 %O Slice-to-volume registration and its potential application to interventional MRI-guided radio-frequency thermal ablation of prostate cancer %O 0278-0062 %O 10.1109/tmi.2003.809078 %O WOS:000183078600005 %X In this study, we registered live-time interventional magnetic resonance imaging (iMRI) slices with a previously obtained high-resolution MRI volume that in turn can be registered with a variety of functional images, e.g., PET, SPECT, for tumor targeting. We created and evaluated a slice-to-volume (SV) registration algorithm with special features for its potential use in iMRI-guided radio-frequency (RF) thermal ablation of prostate cancer. The algorithm features included a multiresolution approach, two similarity measures, and automatic restarting to avoid local minima. Imaging experiments were performed on volunteers using a conventional 1.5-T MR scanner and a clinical 0.2-T C-arm iMRI system under realistic conditions. Both high-resolution MR volumes and actual iMRI image slices were acquired from the same volunteers. Actual and simulated iMRI images were used to test the dependence of SV registration on image noise, receive coil inhomogeneity, and RF needle artifacts. To quantitatively assess registration, we calculated the mean voxel displacement over a volume of interest between SV registration and volume-to-volume registration, which was previously shown to be quite accurate. More than 800 registration experiments were performed. For transverse image slices covering the prostate, the SV registration algorithm was 100% successful with an error of <2 mm, and the average and standard deviation was only 0.4 mm +/- 0.2 mm. Visualizations such as combined sector display and contour overlay showed excellent registration of the prostate and other organs throughout the pelvis. Error was greater when an image slice was obtained at other orientations and positions, mostly because of inconsistent image content such as that from variable rectal And bladder filling. These preliminary experiments indicate that MR SV registration is sufficiently accurate to aid image-guided therapy. %O Times Cited: 54 Lewin, Jonathan/A-4331-2009; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 54 %O ://WOS:000183078600005 %0 Journal Article %A Fei, B. W. %A Kemper, C. %A Wilson, D. L. %D 2003 %T A comparative study of warping and rigid body registration for the prostate and pelvic MR volumes %J Computerized Medical Imaging and Graphics %V 27 %N 4 %O Jul-Aug %P 267-281 %O A comparative study of warping and rigid body registration for the prostate and pelvic MR volumes %O 0895-6111 %O 10.1016/s0895-6111(02)00093-9 %O WOS:000182470100002 %X A three-dimensional warping registration algorithm was created and compared to rigid body registration of magnetic resonance (MR) pelvic volumes including the prostate. The rigid body registration method combines the advantages of mutual information (MI) and correlation coefficient at different resolutions. Warping registration is based upon independent optimization of many interactively placed control points (CP's) using MI and a thin plate spline transformation. More than 100 registration experiments with 17 MR volume pairs determined the quality of registration under conditions simulating potential interventional MRI-guided treatments of prostate cancer. For image pairs that stress rigid body registration (e.g. supine, the diagnostic position, and legs raised, the treatment position), both visual and numerical evaluation methods showed that warping consistently worked better than rigid body. Experiments showed that approximate to 180 strategically placed CP's were sufficiently expressive to capture important features of the deformation. (C) 2002 Elsevier Science Ltd. All rights reserved. %O Times Cited: 39 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 40 %O ://WOS:000182470100002 %0 Book Section %A Fei, B. W. %A Lee, Z. H. %A Boll, D. T. %A Duerk, J. L. %A Lewin, J. S. %A Wilson, D. L. %D 2003 %T Image registration and fusion for interventional MRI guided thermal ablation of the prostate cancer %B Medical Image Computing and Computer-Assisted Intervention - Miccai 2003, Pt 2 %E Ellis, R. E. %E Peters, T. M. %V 2879 %P 364-372 %S Lecture Notes in Computer Science %O 0302-9743 3-540-20464-4 %O Image registration and fusion for interventional MRI guided thermal ablation of the prostate cancer %O WOS:000188180400045 %X We are investigating interventional MRI (iMRI) guided thermal ablation treatment of the prostate cancer. Functional images such as SPECT can detect and localize tumor in the prostate not reliably seen in MRI. We intend to combine the advantages of SPECT with iMRI-guided treatments. Our concept is to first register the low-resolution SPECT with a high resolution MRI volume. Then by registering the high-resolution MR image with iMRI acquisitions, we can, in turn, map the functional data and high-resolution anatomic information to iMRI images for improved tumor targeting. For the first step, we used a mutual information registration method. For the latter, we developed a robust slice to volume (SV) registration algorithm. Image data were acquired from patients and volunteers. Compared to our volume-to-volume registration that was previously evaluated to be quite accurate, the SV registration accuracy is about 0.5 nun for transverse images covering the prostate. With our image registration and fusion software, simulation experiments show that it is feasible to incorporate SPECT and high resolution MRI into the iMRI-guided treatment. %O Times Cited: 18 6th International Conference on Medical Image Computing and Computer-Assisted Intervention NOV 15-18, 2003 MONTREAL, CANADA Robarts Res Inst; No Digital Inc Lewin, Jonathan/A-4331-2009; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 18 %O ://WOS:000188180400045 %0 Book Section %A Fei, B. W. %A Lee, Z. H. %A Duerk, J. L. %A Wilson, D. L. %D 2003 %T Image registration for interventional MRI guided procedures: Interpolation methods, similarity measurements, and applications to the prostate %B Biomedical Image Registration %E Gee, J. C. %E Maintz, J. B. A. %E Vannier, M. W. %V 2717 %P 321-329 %S Lecture Notes in Computer Science %O 0302-9743 3-540-20343-5 %O Image registration for interventional MRI guided procedures: Interpolation methods, similarity measurements, and applications to the prostate %O WOS:000187954800034 %X Nuclear medicine can detect and localize tumor in the prostate not reliably seen in MR. We are investigating methods to combine the advantages of SPECT with interventional MRI (iMRI) guided radiofrequency thermal ablation of the prostate. Our approach is to first register the low-resolution functional images with a high resolution MR volume. Then, by combining the high-resolution MR image with live-time iMRI acquisitions, we can, in turn, include the functional data and high-resolution anatomic information into the iMRI system for improved tumor targeting. In this study, we investigated registration methods for combining noisy, thick iMRI image slices with high-resolution MR volumes. We compared three similarity measures, i.e., normalized mutual information, mutual information, and correlation coefficient; and three interpolation methods, i.e., re-normalized sine, tri-linear, and nearest neighbor. Registration experiments showed that transverse slice images covering the prostate work best with a registration error of approximate to 0.5 mm as compared to our volume-to-volume registration that was previously shown to be quite accurate for these image pairs. %O Times Cited: 10 2nd International Workshop on Biomedical Image Registration JUN 23-24, 2003 Univ Penn, PHILADELPHIA, PA Siemens Med Solut; Siemens Corp Res; Natl Lib Med; Univ Penn, Vice Provost Res Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 10 %O ://WOS:000187954800034 %0 Journal Article %A Fei, B. W. %A Lee, Z. H. %A Boll, D. T. %A Duerk, J. L. %A Sodee, D. B. %A Lewin, J. S. %A Wilson, D. L. %D 2004 %T Registration and fusion of SPECT, high-resolution MRI, and interventional MRI for thermal ablation of prostate cancer %J Ieee Transactions on Nuclear Science %V 51 %N 1 %O Feb %P 177-183 %O Registration and fusion of SPECT, high-resolution MRI, and interventional MRI for thermal ablation of prostate cancer %O 0018-9499 %O 10.1109/tns.2003.823027 %O WOS:000220883100029 %X We are investigating interventional MRI (iMRI) guided radiofrequency thermal ablation for the minimally invasive treatment of the prostate cancer. Nuclear medicine can detect and localize tumor in the prostate not reliably seen in MRI. We intend to combine the advantages of functional images such as nuclear medicine SPECT with iMRI-guided treatments. Our concept is to first register the low-resolution SPECT with a high-resolution MRI volume. Then by registering the high-resolution MR image with live-time iMRI acquisitions, we can, in turn, map the functional data and high-resolution anatomic information to live-time iMRI images for improved tumor targeting. For the first step, we used a three-dimensional mutual information registration method. For the latter, we developed a robust slice to volume (SV) registration algorithm with special features. The concept was tested using image data from three patients and three volunteers. The SV registration accuracy was 0.4 mm +/- 0.2 mm as compared to our volume-to-volume registration that was previously shown to be quite accurate for these image pairs. With our image registration and fusion software, simulation experiments show that it is quite feasible to incorporate SPECT and high-resolution MRI into the iMRI-guided minimally invasive treatment procedures. %O Times Cited: 23 1 Lewin, Jonathan/A-4331-2009; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 23 %O ://WOS:000220883100029 %0 Journal Article %A Fei, B. W. %A Duerk, J. L. %A Sodee, D. B. %A Wilson, D. L. %D 2005 %T Semiautomatic nonrigid registration for the prostate and pelvic MR volumes %J Academic Radiology %V 12 %N 7 %O Jul %P 815-824 %O Semiautomatic nonrigid registration for the prostate and pelvic MR volumes %O 1076-6332 %O 10.1016/j.acra.2005.03.063 %O WOS:000230867600004 %X Rationale and Objectives. Three-dimensional (3D) nonrigid image registration for potential applications in prostate cancer treatment and interventional magnetic resonance (iMRI) imaging-guided therapies were investigated. Materials and Methods. An almost fully automated 3D nonrigid registration algorithm using mutual information and a thin plate spline (TPS) transformation for MR images of the prostate and pelvis were created and evaluated. In the first step, an automatic rigid body registration with special features was used to capture the global transformation. In the second step, local feature points (FPs) were registered using mutual information. An operator entered only five FPs located at the prostate center, left and right hip joints, and left and right distal femurs. The program automatically determined and optimized other FPs at the external pelvic skin surface and along the femurs. More than 600 control points were used to establish a TPS transformation for deformation of the pelvic region and prostate. Ten volume pairs were acquired from three volunteers in the diagnostic (supine) and treatment positions (supine with legs raised). Results. Various visualization techniques showed that warping rectified the significant pelvic misalignment by the rigid-body method. Gray-value measures of registration quality, including mutual information, correlation coefficient, and intensity difference, all improved with warping. The distance between prostate 3D centroids was 0.7 +/- 0.2 mm after warping compared with 4.9 +/- 3.4 mm with rigid-body registration. Conclusion. Semiautomatic nonrigid registration works better than rigid-body registration when patient position is changed greatly between acquisitions. It could be a useful tool for many applications in the management of prostate. %O Times Cited: 28 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 29 %O ://WOS:000230867600004 %0 Journal Article %A Fei, B. W. %A Wang, H. S. %A Muzic, R. F. %A Flask, C. %A Wilson, D. L. %A Duerk, J. L. %A Feyes, D. K. %A Oleinick, N. L. %D 2006 %T Deformable and rigid registration of MRI and microPET images for photodynamic therapy of cancer in mice %J Medical Physics %V 33 %N 3 %O Mar %P 753-760 %O Deformable and rigid registration of MRI and microPET images for photodynamic therapy of cancer in mice %O 0094-2405 %O 10.1118/1.2163831 %O WOS:000236263900018 %X We are investigating imaging techniques to study the tumor response to photodynamic therapy (PDT). Positron emission tomography (PET) can provide physiological and functional information. High-resolution magnetic resonance imaging (MRI) can provide anatomical and morphological changes. Image registration can combine MRI and PET images for improved tumor monitoring. In this study, we acquired high-resolution MRI and microPET F-18-fluorodeoxyglucose (FDG) images from C3H mice with RIF-1 tumors that were treated with Pc 4-based PDT. We developed two registration methods for this application. For registration of the whole mouse body, we used an automatic three-dimensional, normalized mutual information algorithm. For tumor registration, we developed a finite element model (FEM)-based deformable registration scheme. To assess the quality of whole body registration, we performed slice-by-slice review of both image volumes; manually segmented feature organs, such as the left and right kidneys and the bladder, in each slice; and computed the distance between corresponding centroids. Over 40 volume registration experiments were performed with MRI and microPET images. The distance between corresponding centroids of organs was 1.5 +/- 0.4 mm, which is about 2 pixels of microPET images. The mean volume overlap ratios for tumors were 94.7% and 86.3% for the deformable and rigid registration methods, respectively. Registration of high-resolution MRI and microPET. images combines anatomical and functional information of the tumors and provides a useful tool for evaluating photodynamic therapy. (c) 2006 American Association of Physicists in Medicine. %O Times Cited: 27 wang, hesheng/A-6260-2013; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 27 %O ://WOS:000236263900018 %0 Journal Article %A Chen, Xiang %A Gilkeson, Robert C. %A Fei, Baowei %D 2007 %T Automatic 3D-to-2D registration for CT and dual-energy digital radiography for calcification detection %J Medical Physics %V 34 %N 12 %O Dec %P 4934-4943 %O Automatic 3D-to-2D registration for CT and dual-energy digital radiography for calcification detection %O 0094-2405 %O 10.1118/1.2805994 %O WOS:000251910200038 %X We are investigating three-dimensional (3D) to two-dimensional (2D) registration methods for computed tomography (CT) and dual-energy digital radiography (DEDR). CT is an established tool for the detection of cardiac calcification. DEDR could be a cost-effective alternative screening tool. In order to utilize CT as the "gold standard" to evaluate the capability of DEDR images for the detection and localization of calcium, we developed an automatic, intensity-based 3D-to-2D registration method for 3D CT volumes and 2D DEDR images. To generate digitally reconstructed radiography (DRR) from the CT volumes, we developed several projection algorithms using the fast shear-warp method. In particular, we created a Gaussian-weighted projection for this application. We used normalized mutual information (NMI) as the similarity measurement. Simulated projection images from CT values were fused with the corresponding DEDR images to evaluate the localization of cardiac calcification. The registration method was evaluated by digital phantoms, physical phantoms, and clinical data sets. The results from the digital phantoms show that the success rate is 100% with a translation difference of less than 0.8 mm and a rotation difference of less than 0.2 degrees. For physical phantom images, the registration accuracy is 0.43 +/- 0.24 mm. Color overlay and 3D visualization of clinical images show that the two images registered well. The NMI values between the DRR and DEDR images improved from 0.21 +/- 0.03 before registration to 0.25 +/- 0.03 after registration. Registration errors measured from anatomic markers decreased from 27.6 +/- 13.6 mm before registration to 2.5 +/- 0.5 mm after registration. Our results show that the automatic 3D-to-2D registration is accurate and robust. This technique can provide a useful tool for correlating DEDR with CT images for screening coronary artery calcification. %O Times Cited: 10 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 10 %O ://WOS:000251910200038 %0 Journal Article %A Fei, Baowei %A Wang, Hesheng %A Meyers, Joseph D. %A Feyes, Denise K. %A Oleinick, Nancy L. %A Duerk, Jeffrey L. %D 2007 %T High-field magnetic resonance imaging of the response of human prostate cancer to pc 4-based photodynamic therapy in an animal model %J Lasers in Surgery and Medicine %V 39 %N 9 %O Oct %P 723-730 %O High-field magnetic resonance imaging of the response of human prostate cancer to pc 4-based photodynamic therapy in an animal model %O 0196-8092 %O 10.1002/lsm.20576 %O WOS:000250818200005 %X Introduction: High-field magnetic resonance imaging (MRI) is an emerging technique that provides a powerful, non-invasive tool for in vivo studies of cancer therapy in animal models. Photodynamic therapy (PDT) is a relatively new treatment modality for prostate cancer, the second leading cause of cancer mortality in American males. The goal of this study was to evaluate the response of human prostate tumor cells growing as xenografts in athymic nude mice to Pc 4-sensitized PDT. Materials and Methods: PC-3, a cell line derived from a human prostate malignant tumor, was injected intradermally on the back flanks of athymic nude mice. Two tumors were initiated on each mouse. One was treated and the other served as the control. A second-generation photosensitizing drug Pc 4 (0.6 mg/kg body weight) was delivered to each animal by tail vein injection 48 hours before laser illumination (672 nm, 100 mW/cm 2, 150 J/CM2). A dedicated high-field (9.4 T) small-animal MR scanner was used for image acquisitions. A multi-slice multi-echo (MSME) technique, permitting noninvasive in vivo assessment of potential therapeutic effects, was used to measure the T2 values and tumor volumes. Animals were scanned immediately before and after PDT and 24 hours after PDT. T2 values were computed and analyzed for the tumor regions. Results: For the treated tumors, the T2 values significantly increased (P < 0.002) 24 hours after PDT (68.2 +/- 8.5 milliseconds), compared to the pre-PDT values (55.8 +/- 6.6 milliseconds). For the control tumors, there was no significant difference (P = 0.53) between the pre-PDT (52.5 +/- 6.1 milliseconds) and 24-hour post-PDT (54.3 +/- 6.4 milliseconds) values. Histologic analysis showed that PDT-treated tumors demonstrated necrosis and inflammation that was not seen in the control. Discussion: Changes in tumor T2 values measured by multi-slice multi-echo MR imaging provide an assay that could be useful for clinical monitoring of photodynamic therapy of prostate tumors. %O Times Cited: 19 wang, hesheng/A-6260-2013; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 19 %O ://WOS:000250818200005 %0 Journal Article %A Haaga, J. R. %A Exner, A. %A Fei, B. W. %A Seftel, A. D. %D 2007 %T Semiquantitative imaging measurement of baseline and vasomodulated normal prostatic blood flow using sildenafil %J International Journal of Impotence Research %V 19 %N 1 %O Jan-Feb %P 110-113 %O Semiquantitative imaging measurement of baseline and vasomodulated normal prostatic blood flow using sildenafil %O 0955-9930 %O 10.1038/sj.ijir.3901486 %O WOS:000243685500017 %X The physiologic variability of blood flow to the prostate has not been studied until this time. We report the vasoactive effects of sildenafil and phenylephrine on blood flow of the normal prostate. Sildenafil increases prostate blood flow by approximately 75% and phenylephrine reduces the flow incrementally. Administration of these drugs with dynamic contrast-enhanced magnetic resonance imaging may improve the diagnosis of cancerous tissue because according to the literature, tumor angiogenic vessels lack the vasoactive physiologic response of the normal tissue. %O Times Cited: 4 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 4 %O ://WOS:000243685500017 %0 Journal Article %A Bogie, Kath %A Wang, Xiaofeng %A Fei, Baowei %A Sun, Jiayang %D 2008 %T New technique for real-time interface pressure analysis: Getting more out of large image data sets %J Journal of Rehabilitation Research and Development %V 45 %N 4 %O 2008 %P 523-535 %O New technique for real-time interface pressure analysis: Getting more out of large image data sets %O 0748-7711 %O 10.1682/jrrd.2007.03.0046 %O WOS:000258012200005 %X Recent technological improvements have led to increasing clinical use of interface pressure mapping for seating pressure evaluation, which often requires repeated assessments. However, clinical conditions cannot be controlled as closely as research settings, thereby creating challenges to statistical analysis of data. A multistage longitudinal analysis and self-registration (LASR) technique is introduced that emphasizes real-time interface pressure image analysis in three dimensions. Suitable for use in clinical settings, LASR is composed of several modem statistical components, including a segmentation method. The robustness of our segmentation method is also shown. Application of LASR to analysis of data from neuromuscular electrical stimulation (NMES) experiments confirms that NMES improves static seating pressure distributions in the sacral-ischial region over time. Dynamic NMES also improves weight-shifting over time. These changes may reduce the risk of pressure ulcer development. %O Times Cited: 18 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 19 %O ://WOS:000258012200005 %0 Journal Article %A Cheng, Yu %A Samia, Anna C. %A Meyers, Joseph D. %A Panagopoulos, Irene %A Fei, Baowei %A Burda, Clemens %D 2008 %T Highly efficient drug delivery with gold nanoparticle vectors for in vivo photodynamic therapy of cancer %J Journal of the American Chemical Society %V 130 %N 32 %O Aug 13 %P 10643-10647 %O Highly efficient drug delivery with gold nanoparticle vectors for in vivo photodynamic therapy of cancer %O 0002-7863 %O 10.1021/ja801631c %O WOS:000258293800049 %X A highly efficient drug vector for photodynamic therapy (PDT) drug delivery was developed by synthesizing PEGylated gold nanoparticle conjugates, which act as a water-soluble and biocompatible "cage" that allows delivery of a hydrophobic drug to its site of PDT action. The dynamics of drug release in vitro in a two-phase solution system and in vivo in cancer-bearing mice indicates that the process of drug delivery is highly efficient, and passive targeting prefers the tumor site. With the Au NP-Pc 4 conjugates, the drug delivery time required for PDT has been greatly reduced to less than 2 h, compared to 2 days for the free drug. %O Times Cited: 262 Burda, Clemens/C-5107-2008; Burda, Clemens/D-1933-2010; Fei, Baowei /E-6898-2014 Burda, Clemens/0000-0002-7342-2840; Fei, Baowei /0000-0002-9123-9484 0 265 %O ://WOS:000258293800049 %0 Journal Article %A Ciancibello, L. %A Gilkeson, R. %A Fei, B. %D 2009 %T Bismuth Breast Shielding and its Effect on Calcium Score and Dose %J American Journal of Roentgenology %V 192 %N 5 %O May %O Bismuth Breast Shielding and its Effect on Calcium Score and Dose %O 0361-803X %O WOS:000265387200049 %O Times Cited: 0 109th Annual Meeting of the American-Roentgen-Ray-Society APR 27-MAY 01, 2009 Boston, MA Amer Roentgen Ray Soc Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 %O ://WOS:000265387200049 %0 Journal Article %A Wang, Hesheng %A Fei, Baowei %D 2009 %T A modified fuzzy C-means classification method using a multiscale diffusion filtering scheme %J Medical Image Analysis %V 13 %N 2 %O Apr %P 193-202 %O A modified fuzzy C-means classification method using a multiscale diffusion filtering scheme %O 1361-8415 %O 10.1016/j.media.2008.06.014 %O WOS:000265224200001 %X A fully automatic. multiscale fuzzy C-means (MsFCM) classification method for MR images is presented in this paper. We use a diffusion filter to process MR images and to construct a multiscale image series. A multiscale fuzzy C-means classification method is applied along the scales from the coarse to fine levels. The objective function of the conventional fuzzy C-means (FCM) method is modified to allow multiscale classification processing where the result from a coarse scale supervises the classification in the next fine scale. The method is robust for noise and low-contrast MR images because of its multiscale diffusion filtering scheme. The new method was compared with the conventional FCM method and a modified FCM (MFCM) method. Validation studies were performed on synthesized images with various contrasts and on the McGill brain MR image database. Our MsFCM method consistently performed better than the conventional FCM and MFCM methods. The MsFCM method achieved an overlap ratio of greater than 90% as validated by the ground truth. Experiments results on real MR images were given to demonstrate the effectiveness of the proposed method. Our multiscale fuzzy C-means classification method is accurate and robust for various MR images. It can provide a quantitative tool for neuroimaging and other applications. (C) 2008 Elsevier B.V. All rights reserved. %O Times Cited: 39 wang, hesheng/A-6260-2013; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 1 48 %O ://WOS:000265224200001 %0 Journal Article %A Fei, Baowei %A Wang, Hesheng %A Wu, Chunying %A Chiu, Song-mao %D 2010 %T Choline PET for Monitoring Early Tumor Response to Photodynamic Therapy %J Journal of Nuclear Medicine %V 51 %N 1 %O Jan %P 130-138 %O Choline PET for Monitoring Early Tumor Response to Photodynamic Therapy %O 0161-5505 %O 10.2967/jnumed.109.067579 %O WOS:000273263800023 %X Photodynamic therapy (PDT) is a relatively new therapy that has shown promise for treating various cancers in both preclinical and clinical studies. The present study evaluated the potential use of PET with radiolabeled choline to monitor early tumor response to PDT in animal models. Methods: Two human prostate cancer models (PC-3 and CWR22) were studied in athymic nude mice. A second-generation photosensitizer, phthalocyanine 4 (Pc 4), was delivered to each animal by a tail vein injection 48 h before laser illumination. Small-animal PET images with C-11-choline were acquired before PDT and at 1, 24, and 48 h after PDT. Time-activity curves of C-11-choline uptake were analyzed before and after PDT. The percentage of the injected dose per gram of tissue was quantified for both treated and control tumors at each time point. In addition, Pc 4-PDT was performed in cell cultures. Cell viability and C-11-choline uptake in PDT-treated and control cells were measured. Results: For treated tumors, normalized C-11-choline uptake decreased significantly 24 and 48 h after PDT, compared with the same tumors before PDT (P < 0.001). For the control tumors, normalized C-11-choline uptake increased significantly. For mice with CWR22 tumors, the prostate-specific antigen level decreased 24 and 48 h after PDT. Pc 4-PDT in cell culture showed that the treated tumor cells, compared with the control cells, had less than 50% C-11-choline activity at 5, 30, and 45 min after PDT, whereas the cell viability test showed that the treated cells were viable longer than 7 h after PDT. Conclusion: PET with C-11-choline is sensitive for detecting early changes associated with Pc 4-PDT in mouse models of human prostate cancer. Choline PET has the potential to determine whether a PDT-treated tumor responds to treatment within 48 h after therapy. %O Times Cited: 16 wang, hesheng/A-6260-2013; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 16 %O ://WOS:000273263800023 %0 Journal Article %A Wang, Hesheng %A Fei, Baowei %D 2010 %T Diffusion-Weighted MRI for Monitoring Tumor Response to Photodynamic Therapy %J Journal of Magnetic Resonance Imaging %V 32 %N 2 %O Aug %P 409-417 %O Diffusion-Weighted MRI for Monitoring Tumor Response to Photodynamic Therapy %O 1053-1807 %O 10.1002/jmri.22247 %O WOS:000280447300022 %X Purpose: To examine diffusion-weighted MRI (DW-MRI) for assessing the early tumor response to photodynamic therapy (PDT). Materials and Methods: Subcutaneous tumor xenografts of human prostate cancer cells (CWR22) were initiated in athymic nude mice. A second-generation photosensitizer. Pc 4, was delivered to each animal by a tail vein injection 48 h before laser illumination. A dedicated high-field (9.4 Tesla) small animal MR scanner was used to acquire diffusion-weighted MR images pre-PDT and 24 h after the treatment. DW-MRI and apparent diffusion coefficients (ADC) were analyzed for 24 treated and 5 control mice with photosensitizer only or laser light only. Tumor size, prostate specific antigen (PSA) level, and tumor histology were obtained at different time points to examine the treatment effect. Results: Treated mice showed significant tumor size shrinkage and decrease of PSA level within 7 days after the treatment. The average ADC of the 24 treated tumors increased 24 h after PDT (P < 0.001) comparing with pre-PDT. The average ADC was 0.511 +/- 0.119 x 10(-3) mm(2)/s pre-PDT and 0.754 +/- 0.181 x 10(-3) mm(2)/s 24 h after the PDT. There is no significant difference in ADC values pre-PDT and 24 h after PDT in the control tumors (P = 0.20). Conclusion: The change of tumor ADC values measured by DW-MRI may provide a noninvasive imaging marker for monitoring tumor response to Pc 4-PDT as early as 24 h. %O Times Cited: 8 wang, hesheng/A-6260-2013; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 8 %O ://WOS:000280447300022 %0 Journal Article %A Schuster, D. %A Fei, B. %A Fox, T. %A Osunkoya, A. O. %D 2011 %T Histopathologic Correlation of Prostatic Adenocarcinoma on Radical Prostatectomy with Pre-Operative Anti-18F Fluorocyclobutyl-Carboxylic Acid Positron Emission Tomography/Computed Tomography %J Laboratory Investigation %V 91 %O Feb %P 222A-223A %O Histopathologic Correlation of Prostatic Adenocarcinoma on Radical Prostatectomy with Pre-Operative Anti-18F Fluorocyclobutyl-Carboxylic Acid Positron Emission Tomography/Computed Tomography %O 0023-6837 %O WOS:000291285000379 %O Times Cited: 2 1 100th Annual Meeting of the United States and Canadian-Academy-of-Pathology FEB 26-MAR 04, 2011 San Antonio, TX Canadian Acad Pathol Schuster, David/D-6156-2011; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 2 %O ://WOS:000291285000379 %0 Journal Article %A Schuster, D. %A Fei, B. %A Fox, T. %A Osunkoya, A. O. %D 2011 %T Histopathologic Correlation of Prostatic Adenocarcinoma on Radical Prostatectomy with Pre-Operative Anti-18F Fluorocyclobutyl-Carboxylic Acid Positron Emission Tomography/Computed Tomography %J Modern Pathology %V 24 %O Feb %P 222A-223A %O Histopathologic Correlation of Prostatic Adenocarcinoma on Radical Prostatectomy with Pre-Operative Anti-18F Fluorocyclobutyl-Carboxylic Acid Positron Emission Tomography/Computed Tomography %O 0893-3952 %O WOS:000287282301094 %O Times Cited: 0 1 100th Annual Meeting United States-and-Canadian-Academy-of-Pathology FEB 26-MAR 04, 2011 San Antonio, TX United States Canadian Acad Pathol Schuster, David/D-6156-2011 0 %O ://WOS:000287282301094 %0 Journal Article %A Yang, Xiaofeng %A Fei, Baowei %D 2011 %T A multiscale and multiblock fuzzy C-means classification method for brain MR images %J Medical Physics %V 38 %N 6 %O Jun %P 2879-2891 %O A multiscale and multiblock fuzzy C-means classification method for brain MR images %O 0094-2405 %O 10.1118/1.3584199 %O WOS:000291405200008 %X Purpose: Classification of magnetic resonance (MR) images has many clinical and research applications. Because of multiple factors such as noise, intensity inhomogeneity, and partial volume effects, MR image classification can be challenging. Noise in MRI can cause the classified regions to become disconnected. Partial volume effects make the assignment of a single class to one region difficult. Because of intensity inhomogeneity, the intensity of the same tissue can vary with respect to the location of the tissue within the same image. The conventional "hard" classification method restricts each pixel exclusively to one class and often results in crisp results. Fuzzy C-mean (FCM) classification or "soft" segmentation has been extensively applied to MR images, in which pixels are partially classified into multiple classes using varying memberships to the classes. Standard FCM, however, is sensitive to noise and cannot effectively compensate for intensity inhomogeneities. This paper presents a method to obtain accurate MR brain classification using a modified multiscale and multiblock FCM. Methods: An automatic, multiscale and multiblock fuzzy C-means (MsbFCM) classification method with MR intensity correction is presented in this paper. We use a bilateral filter to process MR images and to build a multiscale image series by increasing the standard deviation of spatial function and by reducing the standard deviation of range function. At each scale, we separate the image into multiple blocks and for every block a multiscale fuzzy C-means classification method is applied along the scales from the coarse to fine levels in order to overcome the effect of intensity inhomogeneity. The result from a coarse scale supervises the classification in the next fine scale. The classification method is tested with noisy MR images with intensity inhomogeneity. Results: Our method was compared with the conventional FCM, a modified FCM (MFCM) and multiscale FCM (MsFCM) method. Validation studies were performed on synthesized images with various contrasts, on the simulated brain MR database, and on real MR images. Our MsbFCM method consistently performed better than the conventional FCM, MFCM, and MsFCM methods. The MsbFCM method achieved an overlap ratio of 91% or higher. Experimental results using real MR images demonstrate the effectiveness of the proposed method. Our MsbFCM classification method is accurate and robust for various MR images. Conclusions: As our classification method did not assume a Gaussian distribution of tissue intensity, it could be used on other image data for tissue classification and quantification. The automatic classification method can provide a useful quantification tool in neuroimaging and other applications. (C) 2011 American Association of Physicists in Medicine. [DOI: 10.1118/1.3584199] %O Times Cited: 19 Yang, Xiaofeng/G-9479-2012; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 19 %O ://WOS:000291405200008 %0 Journal Article %A Yang, Xiaofeng %A Fei, Baowei %D 2011 %T A wavelet multiscale denoising algorithm for magnetic resonance (MR) images %J Measurement Science & Technology %V 22 %N 2 %O Feb %O A wavelet multiscale denoising algorithm for magnetic resonance (MR) images %O 0957-0233 %O 10.1088/0957-0233/22/2/025803 %O WOS:000286311200045 %X Based on the Radon transform, a wavelet multiscale denoising method is proposed for MR images. The approach explicitly accounts for the Rician nature of MR data. Based on noise statistics we apply the Radon transform to the original MR images and use the Gaussian noise model to process the MR sinogram image. A translation invariant wavelet transform is employed to decompose the MR 'sinogram' into multiscales in order to effectively denoise the images. Based on the nature of Rician noise we estimate noise variance in different scales. For the final denoised sinogram we apply the inverse Radon transform in order to reconstruct the original MR images. Phantom, simulation brain MR images, and human brain MR images were used to validate our method. The experiment results show the superiority of the proposed scheme over the traditional methods. Our method can reduce Rician noise while preserving the key image details and features. The wavelet denoising method can have wide applications in MRI as well as other imaging modalities. %O Times Cited: 10 Yang, Xiaofeng/G-9479-2012; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 10 %O ://WOS:000286311200045 %0 Journal Article %A Akbari, Hamed %A Fei, Baowei %D 2012 %T 3D ultrasound image segmentation using wavelet support vector machines %J Medical Physics %V 39 %N 6 %O Jun %P 2972-2984 %O 3D ultrasound image segmentation using wavelet support vector machines %O 0094-2405 %O 10.1118/1.4709607 %O WOS:000308905800004 %X Purpose: Transrectal ultrasound (TRUS) imaging is clinically used in prostate biopsy and therapy. Segmentation of the prostate on TRUS images has many applications. In this study, a three-dimensional (3D) segmentation method for TRUS images of the prostate is presented for 3D ultrasound-guided biopsy. Methods: This segmentation method utilizes a statistical shape, texture information, and intensity profiles. A set of wavelet support vector machines (W-SVMs) is applied to the images at various subregions of the prostate. The W-SVMs are trained to adaptively capture the features of the ultrasound images in order to differentiate the prostate and nonprostate tissue. This method consists of a set of wavelet transforms for extraction of prostate texture features and a kernel-based support vector machine to classify the textures. The voxels around the surface of the prostate are labeled in sagittal, coronal, and transverse planes. The weight functions are defined for each labeled voxel on each plane and on the model at each region. In the 3D segmentation procedure, the intensity profiles around the boundary between the tentatively labeled prostate and nonprostate tissue are compared to the prostate model. Consequently, the surfaces are modified based on the model intensity profiles. The segmented prostate is updated and compared to the shape model. These two steps are repeated until they converge. Manual segmentation of the prostate serves as the gold standard and a variety of methods are used to evaluate the performance of the segmentation method. Results: The results from 40 TRUS image volumes of 20 patients show that the Dice overlap ratio is 90.3% +/- 2.3% and that the sensitivity is 87.7% +/- 4.9%. Conclusions: The proposed method provides a useful tool in our 3D ultrasound image-guided prostate biopsy and can also be applied to other applications in the prostate. (C) 2012 American Association of Physicists in Medicine. [http://dx.doi.org/10.1118/1.4709607] %O Times Cited: 12 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 12 %O ://WOS:000308905800004 %0 Journal Article %A Akbari, Hamed %A Halig, Luma V. %A Schuster, David M. %A Osunkoya, Adeboye %A Master, Viraj %A Nieh, Peter T. %A Chen, Georgia Z. %A Fei, Baowei %D 2012 %T Hyperspectral imaging and quantitative analysis for prostate cancer detection %J Journal of Biomedical Optics %V 17 %N 7 %O Jul %O Hyperspectral imaging and quantitative analysis for prostate cancer detection %O 1083-3668 %O 10.1117/1.jbo.17.7.076005 %O WOS:000307989500032 %X Hyperspectral imaging (HSI) is an emerging modality for various medical applications. Its spectroscopic data might be able to be used to noninvasively detect cancer. Quantitative analysis is often necessary in order to differentiate healthy from diseased tissue. We propose the use of an advanced image processing and classification method in order to analyze hyperspectral image data for prostate cancer detection. The spectral signatures were extracted and evaluated in both cancerous and normal tissue. Least squares support vector machines were developed and evaluated for classifying hyperspectral data in order to enhance the detection of cancer tissue. This method was used to detect prostate cancer in tumor-bearing mice and on pathology slides. Spatially resolved images were created to highlight the differences of the reflectance properties of cancer versus those of normal tissue. Preliminary results with 11 mice showed that the sensitivity and specificity of the hyperspectral image classification method are 92.8% to 2.0% and 96.9% to 1.3%, respectively. Therefore, this imaging method may be able to help physicians to dissect malignant regions with a safe margin and to evaluate the tumor bed after resection. This pilot study may lead to advances in the optical diagnosis of prostate cancer using HSI technology. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JBO.17.7.076005] %O Times Cited: 17 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 18 %O ://WOS:000307989500032 %0 Journal Article %A Fei, B. %A Schuster, D. %A Master, V. %A Nieh, P. %D 2012 %T Incorporating PET/CT Images Into 3D Ultrasound-Guided Biopsy of the Prostate %J Medical Physics %V 39 %N 6 %O Jun %P 3888-3888 %O Incorporating PET/CT Images Into 3D Ultrasound-Guided Biopsy of the Prostate %O 0094-2405 %O WOS:000308905805331 %O Times Cited: 4 54th Annual Meeting and Exhibition of the American-Association-of-Physicists-in-Medicine (AAPM) JUL 29-AUG 02, 2012 Charlotte, NC Amer Assoc Physicists Med (AAPM) Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 4 %O ://WOS:000308905805331 %0 Journal Article %A Fei, Baowei %A Yang, Xiaofeng %A Nye, Jonathon A. %A Aarsvold, John N. %A Raghunath, Nivedita %A Cervo, Morgan %A Stark, Rebecca %A Meltzer, Carolyn C. %A Votaw, John R. %D 2012 %T MR/PET quantification tools: Registration, segmentation, classification, and MR-based attenuation correction %J Medical Physics %V 39 %N 10 %O Oct %P 6443-6454 %O MR/PET quantification tools: Registration, segmentation, classification, and MR-based attenuation correction %O 0094-2405 %O 10.1118/1.4754796 %O WOS:000310101900062 %X Purpose: Combined MR/PET is a relatively new, hybrid imaging modality. A human MR/PET prototype system consisting of a Siemens 3T Trio MR and brain PET insert was installed and tested at our institution. Its present design does not offer measured attenuation correction (AC) using traditional transmission imaging. This study is the development of quantification tools including MR-based AC for quantification in combined MR/PET for brain imaging. Methods: The developed quantification tools include image registration, segmentation, classification, and MR-based AC. These components were integrated into a single scheme for processing MR/PET data. The segmentation method is multiscale and based on the Radon transform of brain MR images. It was developed to segment the skull on T1-weighted MR images. A modified fuzzy C-means classification scheme was developed to classify brain tissue into gray matter, white matter, and cerebrospinal fluid. Classified tissue is assigned an attenuation coefficient so that AC factors can be generated. PET emission data are then reconstructed using a three-dimensional ordered sets expectation maximization method with the MR-based AC map. Ten subjects had separate MR and PET scans. The PET with [C-11]PIB was acquired using a high-resolution research tomography (HRRT) PET. MR-based AC was compared with transmission (TX)-based AC on the HRRT. Seventeen volumes of interest were drawn manually on each subject image to compare the PET activities between the MR-based and TX-based AC methods. Results: For skull segmentation, the overlap ratio between our segmented results and the ground truth is 85.2 +/- 2.6%. Attenuation correction results from the ten subjects show that the difference between the MR and TX-based methods was <6.5%. Conclusions: MR-based AC compared favorably with conventional transmission-based AC. Quantitative tools including registration, segmentation, classification, and MR-based AC have been developed for use in combined MR/PET. (C) 2012 American Association of Physicists in Medicine. [http://dx.doi.org/10.1118/1.4754796] %O Times Cited: 13 Yang, Xiaofeng/G-9479-2012; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 13 %O ://WOS:000310101900062 %0 Journal Article %A Feng, S. S. J. %A Bliznakova, K. %A Qin, X. %A Fei, B. %A Sechopoulos, I. %D 2012 %T Characterization of the Homogeneous Breast Tissue Mixture Approximation for Breast Image Dosimetry %J Medical Physics %V 39 %N 6 %O Jun %P 3878-3878 %O Characterization of the Homogeneous Breast Tissue Mixture Approximation for Breast Image Dosimetry %O 0094-2405 %O WOS:000308905805294 %O Times Cited: 1 54th Annual Meeting and Exhibition of the American-Association-of-Physicists-in-Medicine (AAPM) JUL 29-AUG 02, 2012 Charlotte, NC Amer Assoc Physicists Med (AAPM) Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 1 %O ://WOS:000308905805294 %0 Journal Article %A MacDonald, Tobey %A Liu, Jingbo %A Munson, Jenny %A Park, Jaekeun %A Wang, Kenty %A Fei, Baowei %A Bellamkonda, Ravi %A Arbiser, Jack %D 2012 %T THE APPLICATION OF NANOPARTICLE LIPOSOME-IMPRAMINE BLUE IN THE TREATMENT OF MEDULLOBLASTOMA IN THE SmoA1 TRANSGENIC MICE %J Neuro-Oncology %V 14 %O Jun %P 83-83 %O THE APPLICATION OF NANOPARTICLE LIPOSOME-IMPRAMINE BLUE IN THE TREATMENT OF MEDULLOBLASTOMA IN THE SmoA1 TRANSGENIC MICE %O 1522-8517 %O WOS:000308394400309 %O Times Cited: 0 1 15th International Symposium on Pediatric Neuro-Oncology (ISPNO) JUN 24-27, 2012 Toronto, CANADA Fei, Baowei /E-6898-2014; MacDonald, Tobey/D-4554-2013 Fei, Baowei /0000-0002-9123-9484; 0 %O ://WOS:000308394400309 %0 Journal Article %A Mafi, John N. %A Fei, Baowei %A Roble, Sharon %A Dota, Anthony %A Katrapati, Prashanth %A Bezerra, Hiram G. %A Wang, Hesheng %A Wang, Wei %A Ciancibello, Leslie %A Costa, Marco %A Simon, Daniel I. %A Orringer, Carl E. %A Gilkeson, Robert C. %D 2012 %T Assessment of Coronary Artery Calcium Using Dual-Energy Subtraction Digital Radiography %J Journal of Digital Imaging %V 25 %N 1 %O Feb %P 129-136 %O Assessment of Coronary Artery Calcium Using Dual-Energy Subtraction Digital Radiography %O 0897-1889 %O 10.1007/s10278-011-9385-y %O WOS:000304113400019 %X Cardiovascular disease is the leading cause of global mortality, yet its early detection remains a vexing problem of modern medicine. Although the computed tomography (CT) calcium score predicts cardiovascular risk, relatively high cost ($250-400) and radiation dose (13 mSv) limit its universal utility as a screening tool. Dual-energy digital subtraction radiography (DE; <$60, 0.07 mSv) enables detection of calcified structures with high sensitivity. In this pilot study, we examined DE radiography's ability to quantify coronary artery calcification (CAC). We identified 25 patients who underwent non-contrast CT and DE chest imaging performed within 12 months using documented CAC as the major inclusion criteria. A DE calcium score was developed based on pixel intensity multiplied by the area of the calcified plaque. DE scores were plotted against CT scores. Subsequently, a validation cohort of 14 additional patients was independently evaluated to confirm the accuracy and precision of CAC quantification, yielding a total of 39 subjects. Among all subjects (n=39), the DE score demonstrated a correlation coefficient of 0.87 (p<0.0001) when compared with the CT score. For the 13 patients with CT scores of <400, the correlation coefficient was -0.26. For the 26 patients with CT scores of >= 400, the correlation coefficient yielded 0.86. This pilot study demonstrates the feasibility of DE radiography to identify patients at the highest cardiovascular risk. DE radiography's accuracy at lower scores remains unclear. Further evaluation of DE radiography as an inexpensive and low-radiation imaging tool to diagnose cardiovascular disease appears warranted. %O Times Cited: 5 wang, hesheng/A-6260-2013; Fei, Baowei /E-6898-2014; Roble, Sharon/E-3966-2011 Fei, Baowei /0000-0002-9123-9484; 0 5 %O ://WOS:000304113400019 %0 Journal Article %A Sechopoulos, Ioannis %A Bliznakova, Kristina %A Qin, Xulei %A Fei, Baowei %A Feng, Steve Si Jia %D 2012 %T Characterization of the homogeneous tissue mixture approximation in breast imaging dosimetry %J Medical Physics %V 39 %N 8 %O Aug %P 5050-5059 %O Characterization of the homogeneous tissue mixture approximation in breast imaging dosimetry %O 0094-2405 %O 10.1118/1.4737025 %O WOS:000307917600043 %X Purpose: To compare the estimate of normalized glandular dose in mammography and breast CT imaging obtained using the actual glandular tissue distribution in the breast to that obtained using the homogeneous tissue mixture approximation. Methods: Twenty volumetric images of patient breasts were acquired with a dedicated breast CT prototype system and the voxels in the breast CT images were automatically classified into skin, adipose, and glandular tissue. The breasts in the classified images underwent simulated mechanical compression to mimic the conditions present during mammographic acquisition. The compressed thickness for each breast was set to that achieved during each patient's last screening cranio-caudal (CC) acquisition. The volumetric glandular density of each breast was computed using both the compressed and uncompressed classified images, and additional images were created in which all voxels representing adipose and glandular tissue were replaced by a homogeneous mixture of these two tissues in a proportion corresponding to each breast's volumetric glandular density. All four breast images (compressed and uncompressed; heterogeneous and homogeneous tissue) were input into Monte Carlo simulations to estimate the normalized glandular dose during mammography (compressed breasts) and dedicated breast-CT (uncompressed breasts). For the mammography simulations the x-ray spectra used was that used during each patient's last screening CC acquisition. For the breast CT simulations, two x-ray spectra were used, corresponding to the x-ray spectra with the lowest and highest energies currently being used in dedicated breast CT prototype systems under clinical investigation. The resulting normalized glandular dose for the heterogeneous and homogeneous versions of each breast for each modality was compared. Results: For mammography, the normalized glandular dose based on the homogeneous tissue approximation was, on average, 27% higher than that estimated using the true heterogeneous glandular tissue distribution (Wilcoxon Signed Rank Test p = 0.00046). For dedicated breast CT, the overestimation of normalized glandular dose was, on average, 8% (49 kVp spectrum, p = 0.00045) and 4% (80 kVp spectrum, p = 0.000089). Only two cases in mammography and two cases in dedicated breast CT with a tube voltage of 49 kVp resulted in lower dose estimates for the homogeneous tissue approximation compared to the heterogeneous tissue distribution. Conclusions: The normalized glandular dose based on the homogeneous tissue mixture approximation results in a significant overestimation of dose to the imaged breast. This overestimation impacts the use of dose estimates in absolute terms, such as for risk estimates, and may impact some comparative studies, such as when modalities or techniques with different x-ray energies are used. The error introduced by the homogeneous tissue mixture approximation in higher energy x-ray modalities, such as dedicated breast CT, although statistically significant, may not be of clinical concern. Further work is required to better characterize this overestimation and potentially develop new metrics or correction factors to better estimate the true glandular dose to breasts undergoing imaging with ionizing radiation. 0 2012 American Association of Physicists in Medicine. [http://dx.doi.org/10.1118/1.4737025] %O Times Cited: 6 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 6 %O ://WOS:000307917600043 %0 Journal Article %A Wang, Hesheng %A Fei, Baowei %D 2012 %T An MR image-guided, voxel-based partial volume correction method for PET images %J Medical Physics %V 39 %N 1 %O Jan %P 179-194 %O An MR image-guided, voxel-based partial volume correction method for PET images %O 0094-2405 %O 10.1118/1.3665704 %O WOS:000298812200020 %X Purpose: Partial volume effect in positron emission tomography (PET) can cause incorrect quantification of radiopharmaceutical uptake in functional imaging. A PET partial volume correction method is presented to attenuate partial volume blurring and to yield voxel-based corrected PET images. Methods: By modeling partial volume effect as a convolution of point spread function of the PET scanner, the reconstructed PET images are corrected by iterative deconvolution with an edge-preserving smoothness constraint. The constraint is constructed to restore discontinuities extracted from coregistered MR images but maintains the smoothness in radioactivity distribution. The correction is implemented in a Bayesian deconvolution framework and is solved by a conjugate gradient method. The performance of the method was compared with the geometric transfer matrix (GTM) method on a simulated dataset. The method was evaluated on synthesized brain FDG-PET data and phantom MRI-PET experiments. Results: The true PET activity of objects with a size of greater than the full-width at half maximum of the point spread function has been effectively restored in the simulated data. The partial volume correction method is quantitatively comparable to the GTM method. For synthesized FDG-PET with true activity 0 mu ci/cc for cerebrospinal fluid (CSF), 228 mu ci/cc for white matter (WM), and 621 mu ci/cc for gray matter (GM), the method has improved the radioactivity quantification from 186 +/- 16 mu ci/cc to 30 +/- 7 mu ci/cc in CSF, 317 +/- 15 mu ci/cc to 236 +/- 10 mu ci/cc for WM, 438 +/- 4 mu ci/ cc to 592 +/- 5 mu ci/cc for GM. Both visual and quantitative assessments show improvement of partial volume correction in the synthesized and phantom experiments. Conclusions: The partial volume correction method improves the quantification of PET images. The method is comparable to the GTM method but does not need MR image segmentation or prior tracer distribution information. The voxel-based method can be particularly useful for combined PET/MRI studies. (C) 2012 American Association of Physicists in Medicine. [DOI: 10.1118/1.3665704] %O Times Cited: 12 wang, hesheng/A-6260-2013; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 12 %O ://WOS:000298812200020 %0 Journal Article %A Yang, Xiaofeng %A Wu, Shengyong %A Sechopoulos, Ioannis %A Fei, Baowei %D 2012 %T Cupping artifact correction and automated classification for high-resolution dedicated breast CT images Xiaofeng Yang and Shengyong Wu %J Medical Physics %V 39 %N 10 %O Oct %P 6397-6406 %O Cupping artifact correction and automated classification for high-resolution dedicated breast CT images Xiaofeng Yang and Shengyong Wu %O 0094-2405 %O 10.1118/1.4754654 %O WOS:000310101900058 %X Purpose: To develop and test an automated algorithm to classify the different tissues present in dedicated breast CT images. Methods: The original CT images are first corrected to overcome cupping artifacts, and then a multiscale bilateral filter is used to reduce noise while keeping edge information on the images. As skin and glandular tissues have similar CT values on breast CT images, morphologic processing is used to identify the skin mask based on its position information. A modified fuzzy C-means (FCM) classification method is then used to classify breast tissue as fat and glandular tissue. By combining the results of the skin mask with the FCM, the breast tissue is classified as skin, fat, and glandular tissue. To evaluate the authors' classification method, the authors use Dice overlap ratios to compare the results of the automated classification to those obtained by manual segmentation on eight patient images. Results: The correction method was able to correct the cupping artifacts and improve the quality of the breast CT images. For glandular tissue, the overlap ratios between the authors' automatic classification and manual segmentation were 91.6% +/- 2.0%. Conclusions: A cupping artifact correction method and an automatic classification method were applied and evaluated for high-resolution dedicated breast CT images. Breast tissue classification can provide quantitative measurements regarding breast composition, density, and tissue distribution. (c) 2012 American Association of Physicists in Medicine. [http://dx.doi.org/10.1118/1.4754654] %O Times Cited: 11 Yang, Xiaofeng/G-9479-2012; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 11 %O ://WOS:000310101900058 %0 Journal Article %A Qin, Xulei %A Cong, Zhibin %A Fei, Baowei %D 2013 %T Automatic segmentation of right ventricular ultrasound images using sparse matrix transform and a level set %J Physics in Medicine and Biology %V 58 %N 21 %O Nov 7 %P 7609-7624 %O Automatic segmentation of right ventricular ultrasound images using sparse matrix transform and a level set %O 0031-9155 %O 10.1088/0031-9155/58/21/7609 %O WOS:000326377100012 %X An automatic segmentation framework is proposed to segment the right ventricle (RV) in echocardiographic images. The method can automatically segment both epicardial and endocardial boundaries from a continuous echocardiography series by combining sparse matrix transform, a training model, and a localized region-based level set. First, the sparse matrix transform extracts main motion regions of the myocardium as eigen-images by analyzing the statistical information of the images. Second, an RV training model is registered to the eigen-images in order to locate the position of the RV. Third, the training model is adjusted and then serves as an optimized initialization for the segmentation of each image. Finally, based on the initializations, a localized, region-based level set algorithm is applied to segment both epicardial and endocardial boundaries in each echocardiograph. Three evaluation methods were used to validate the performance of the segmentation framework. The Dice coefficient measures the overall agreement between the manual and automatic segmentation. The absolute distance and the Hausdorff distance between the boundaries from manual and automatic segmentation were used to measure the accuracy of the segmentation. Ultrasound images of human subjects were used for validation. For the epicardial and endocardial boundaries, the Dice coefficients were 90.8 +/- 1.7% and 87.3 +/- 1.9%, the absolute distances were 2.0 +/- 0.42 mm and 1.79 +/- 0.45 mm, and the Hausdorff distances were 6.86 +/- 1.71 mm and 7.02 +/- 1.17 mm, respectively. The automatic segmentation method based on a sparse matrix transform and level set can provide a useful tool for quantitative cardiac imaging. %O Times Cited: 7 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 7 %O ://WOS:000326377100012 %0 Journal Article %A Sechopoulos, Ioannis %A Bliznakova, Kristina %A Fei, Baowei %D 2013 %T Power spectrum analysis of the x-ray scatter signal in mammography and breast tomosynthesis projections %J Medical Physics %V 40 %N 10 %O Oct %O Power spectrum analysis of the x-ray scatter signal in mammography and breast tomosynthesis projections %O 0094-2405 %O 10.1118/1.4820442 %O WOS:000325394400021 %X Purpose: To analyze the frequency domain characteristics of the signal in mammography images and breast tomosynthesis projections with patient tissue texture due to detected scattered x-rays. Methods: Acquisitions of x-ray projection images of 19 different patient breasts were simulated using previously acquired volumetric patient images. Acquisition of these images was performed with a dedicated breast CT prototype system, and the images were classified into voxels representing skin, adipose, and glandular tissue with a previously validated automated algorithm. The classified three dimensional images then underwent simulated mechanical compression representing that which is performed during acquisition of mammography and breast tomosynthesis images. The acquisition of projection images of each patient breast was simulated using Monte Carlo methods with each simulation resulting in two images: one of the primary (non-scattered) signal and one of the scatter signal. To analyze the scatter signal for both mammography and breast tomosynthesis, two projections images of each patient breast were simulated, one with the x-ray source positioned at 0 degrees (mammography and central tomosynthesis projection) and at 30 degrees (wide tomosynthesis projection). The noise power spectra (NPS) for both the scatter signal alone and the total signal (primary + scatter) for all images were obtained and the combined results of all patients analyzed. The total NPS was fit to the expected power-law relationship NPS(f) = k/f boolean AND beta and the results were compared with those previously published on the power spectrum characteristics of mammographic texture. The scatter signal alone was analyzed qualitatively and a power-law fit was also performed. Results: The mammography and tomosynthesis projections of three patient breasts were too small to analyze, so a total of 16 patient breasts were analyzed. The values of beta for the total signal of the 0 degrees projections agreed well with previously published results. As expected, the scatter power spectrum reflected a fast drop-off with increasing spatial frequency, with a reduction of four orders of magnitude by 0.1 lp/mm. The beta values for the scatter signal were 6.14 and 6.39 for the 0 degrees and 30 degrees projections, respectively. Conclusions: Although the low-frequency characteristics of scatter in mammography and breast tomosynthesis were known, a quantitative analysis of the frequency domain characteristics of this signal was needed in order to optimize previously proposed software-based x-ray scatter reduction algorithms for these imaging modalities. (c) 2013 American Association of Physicists in Medicine. %O Times Cited: 0 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 %O ://WOS:000325394400021 %0 Journal Article %A Sechopoulos, I. %A Fei, B. %A Bliznakova, K. %D 2013 %T Spatial Frequency Characterization of the X-Ray Scatter Signal in Breast Imaging %J Medical Physics %V 40 %N 6 %O Jun %O Spatial Frequency Characterization of the X-Ray Scatter Signal in Breast Imaging %O 0094-2405 %O 10.1118/1.4815665 %O WOS:000336849900082 %O Times Cited: 0 0 %O ://WOS:000336849900082 %0 Journal Article %A Wang, Hesheng %A Fei, Baowei %D 2013 %T Nonrigid point registration for 2D curves and 3D surfaces and its various applications %J Physics in Medicine and Biology %V 58 %N 12 %O Jun 21 %P 4315-4330 %O Nonrigid point registration for 2D curves and 3D surfaces and its various applications %O 0031-9155 %O 10.1088/0031-9155/58/12/4315 %O WOS:000319966100023 %X A nonrigid B-spline-based point-matching (BPM) method is proposed to match dense surface points. The method solves both the point correspondence and nonrigid transformation without features extraction. The registration method integrates a motion model, which combines a global transformation and a B-spline-based local deformation, into a robust point-matching framework. The point correspondence and deformable transformation are estimated simultaneously by fuzzy correspondence and by a deterministic annealing technique. Prior information about global translation, rotation and scaling is incorporated into the optimization. A local B-spline motion model decreases the degrees of freedom for optimization and thus enables the registration of a larger number of feature points. The performance of the BPM method has been demonstrated and validated using synthesized 2D and 3D data, mouse MRI and micro-CT images. The proposed BPM method can be used to register feature point sets, 2D curves, 3D surfaces and various image data. %O Times Cited: 4 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 4 %O ://WOS:000319966100023 %0 Journal Article %A Yang, Xiaofeng %A Fei, Baowei %D 2013 %T Multiscale segmentation of the skull in MR images for MRI-based attenuation correction of combined MR/PET %J Journal of the American Medical Informatics Association %V 20 %N 6 %O Nov %P 1037-1045 %O Multiscale segmentation of the skull in MR images for MRI-based attenuation correction of combined MR/PET %O 1067-5027 %O 10.1136/amiajnl-2012-001544 %O WOS:000325557600006 %X Background and objective Combined magnetic resonance/positron emission tomography (MR/PET) is a relatively new, hybrid imaging modality. MR-based attenuation correction often requires segmentation of the bone on MR images. In this study, we present an automatic segmentation method for the skull on MR images for attenuation correction in brain MR/PET applications. Materials and methods Our method transforms T1-weighted MR images to the Radon domain and then detects the features of the skull image. In the Radon domain we use a bilateral filter to construct a multiscale image series. For the repeated convolution we increase the spatial smoothing in each scale and make the width of the spatial and range Gaussian function doubled in each scale. Two filters with different kernels along the vertical direction are applied along the scales from the coarse to fine levels. The results from a coarse scale give a mask for the next fine scale and supervise the segmentation in the next fine scale. The use of the multiscale bilateral filtering schemeis to improve the robustness of the method for noise MR images. After combining the two filtered sinograms, the reciprocal binary sinogram of the skull is obtained for the reconstruction of the skull image. Results This method has been tested with brain phantom data, simulated brain data, and real MRI data. For real MRI data the Dice overlap ratios are 92.2%1.9% between our segmentation and manual segmentation. Conclusions The multiscale segmentation method is robust and accurate and can be used for MRI-based attenuation correction in combined MR/PET. %O Times Cited: 2 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 2 %O ://WOS:000325557600006 %0 Journal Article %A Zhen, Zipeng %A Tang, Wei %A Guo, Cunlan %A Chen, Hongmin %A Lin, Xin %A Liu, Gang %A Fei, Baowei %A Chen, Xiaoyuan %A Xu, Binqian %A Xie, Jin %D 2013 %T Ferritin Nanocages To Encapsulate and Deliver Photosensitizers for Efficient Photodynamic Therapy against Cancer %J Acs Nano %V 7 %N 8 %O Aug %P 6988-6996 %O Ferritin Nanocages To Encapsulate and Deliver Photosensitizers for Efficient Photodynamic Therapy against Cancer %O 1936-0851 %O 10.1021/nn402199g %O WOS:000323810600060 %X Photodynamic therapy is an emerging treatment modality that is under, intensive preclinical and clinical investigations for many types of disease including cancer. Despite the promise, there is a lack of a reliable drug delivery vehicle that can transport photosensitizers (PSs) to tumors in a site-specific manner: Previous efforts have been focused on polymer- or liposome-based nanocarriers, which are usually associated with a suboptimal PS loading rate and a large particle size. We report herein that a RGD4C-modified ferritin (RFRT), a protein-based nanoparticle, can serve as a safe and efficient PS vehicle. Zinc hexadecafluorophthalocyanine (ZnF16Pc), a potent PS with a high 102 quantum yield but poor water solubility, can be encapsulated into RFRTs with a loading rate as high as similar to 60 wt % (i.e, 13 mg of ZnF16Pc can be loaded on 1 mg of RAM), which far exceeds those reported previously.. Despite the high loading, the ZnF16Pc-loaded Fans (P-RFRTs) show an overall particle size of 18.6 +/- 2.6 nm, which is significantly smaller than other PS-nanocarrier conjugates: When tested on U87MG subcutaneous tumor models, P-RFRTs showed a high tumor accumulation rate (tumor-to-normal tissue ratio of 26.82 +/- 4.07at 24 h), a good tumor inhibition rate (8164% on day 12), as well as minimal toxicity to the skin and other major organs. This technology can be extended to deliver other metal-containing PSs and holds great clinical translation potential. %O Times Cited: 19 Guo, Cunlan/E-8077-2011; Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 20 %O ://WOS:000323810600060 %0 Journal Article %A Liu, Hong %A Wang, Jie %A Xu, Xiangyang %A Song, Enmin %A Wang, Qian %A Jin, Renchao %A Hung, Chih-Cheng %A Fei, Baowei %D 2014 %T A robust and accurate center-frequency estimation (RACE) algorithm for improving motion estimation performance of Sin Mod on tagged cardiac MR images without known tagging parameters %J Magnetic Resonance Imaging %V 32 %N 9 %O Nov %P 1139-1155 %O A robust and accurate center-frequency estimation (RACE) algorithm for improving motion estimation performance of Sin Mod on tagged cardiac MR images without known tagging parameters %O 0730-725X %O 10.1016/j.mri.2014.07.005 %O WOS:000342546700010 %X A robust and accurate center-frequency (CF) estimation (RACE) algorithm for improving the performance of the local sine-wave modeling (SinMod) method, which is a good motion estimation method for tagged cardiac magnetic resonance (MR) images, is proposed in this study. The RACE algorithm can automatically, effectively and efficiently produce a very appropriate CF estimate for the SinMod method, under the circumstance that the specified tagging parameters are unknown, on account of the following two key techniques: (1) the well-known mean-shift algorithm, which can provide accurate and rapid CF estimation; and (2) an original two-direction-combination strategy, which can further enhance the accuracy and robustness of CF estimation. Some other available CF estimation algorithms are brought out for comparison. Several validation approaches that can work on the real data without ground truths are specially designed. Experimental results on human body in vivo cardiac data demonstrate the significance of accurate CF estimation for SinMod, and validate the effectiveness of RACE in facilitating the motion estimation performance of SinMod. (C) 2014 Elsevier Inc. All rights reserved. %O Times Cited: 0 0 %O ://WOS:000342546700010 %0 Journal Article %A Lu, Guolan %A Fei, Baowei %D 2014 %T Medical hyperspectral imaging: a review %J Journal of Biomedical Optics %V 19 %N 1 %O Jan %O Medical hyperspectral imaging: a review %O 1083-3668 %O 10.1117/1.jbo.19.1.010901 %O WOS:000331892700001 %X Hyperspectral imaging (HSI) is an emerging imaging modality for medical applications, especially in disease diagnosis and image-guided surgery. HSI acquires a three-dimensional dataset called hypercube, with two spatial dimensions and one spectral dimension. Spatially resolved spectral imaging obtained by HSI provides diagnostic information about the tissue physiology, morphology, and composition. This review paper presents an overview of the literature on medical hyperspectral imaging technology and its applications. The aim of the survey is threefold: an introduction for those new to the field, an overview for those working in the field, and a reference for those searching for literature on a specific application. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI. %O Times Cited: 9 Fei, Baowei /E-6898-2014 Fei, Baowei /0000-0002-9123-9484 0 9 %O ://WOS:000331892700001 %0 Journal Article %A Lu, Guolan %A Halig, Luma %A Wang, Dongsheng %A Qin, Xulei %A Chen, Zhuo Georgia %A Fei, Baowei %D 2014 %T Spectral-spatial classification for noninvasive cancer detection using hyperspectral imaging %J Journal of Biomedical Optics %V 19 %N 10 %O Oct %O Spectral-spatial classification for noninvasive cancer detection using hyperspectral imaging %O 1083-3668 %O 10.1117/1.jbo.19.10.106004 %O WOS:000345837200021 %X Early detection of malignant lesions could improve both survival and quality of life of cancer patients. Hyperspectral imaging (HSI) has emerged as a powerful tool for noninvasive cancer detection and diagnosis, with the advantage of avoiding tissue biopsy and providing diagnostic signatures without the need of a contrast agent in real time. We developed a spectral-spatial classification method to distinguish cancer from normal tissue on hyperspectral images. We acquire hyperspectral reflectance images from 450 to 900 nm with a 2-nm increment from tumor-bearing mice. In our animal experiments, the HSI and classification method achieved a sensitivity of 93.7% and a specificity of 91.3%. The preliminary study demonstrated that HSI has the potential to be applied in vivo for noninvasive detection of tumors. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE) %O Times Cited: 0 0 %O ://WOS:000345837200021 %0 Journal Article %A Malliori, A. %A Bliznakova, K. %A Sechopoulos, I. %A Kamarianakis, Z. %A Fei, B. %A Pallikarakis, N. %D 2014 %T Breast tomosynthesis with monochromatic beams: a feasibility study using Monte Carlo simulations %J Physics in Medicine and Biology %V 59 %N 16 %O Aug 21 %P 4681-4696 %O Breast tomosynthesis with monochromatic beams: a feasibility study using Monte Carlo simulations %O 0031-9155 %O 10.1088/0031-9155/59/16/4681 %O WOS:000341379900015 %X The aim of this study is to investigate the impact on image quality of using monochromatic beams for lower dose breast tomosynthesis (BT). For this purpose, modeling and simulation of BT and mammography imaging processes have been performed using two x-ray beams: one at 28 kVp and a monochromatic one at 19 keV at different entrance surface air kerma ranging between 0.16 and 5.5 mGy. Two 4 cm thick computational breast models, in a compressed state, were used: one simple homogeneous and one heterogeneous based on CT breast images, with compositions of 50% glandular-50% adipose and 40% glandular-60% adipose tissues by weight, respectively. Modeled lesions, representing masses and calcifications, were inserted within these breast phantoms. X-ray transport in the breast models was simulated with previously developed and validated Monte Carlo application. Results showed that, for the same incident photon fluence, the use of the monochromatic beam in BT resulted in higher image quality compared to the one using polychromatic acquisition, especially in terms of contrast. For the homogenous phantom, the improvement ranged between 15% and 22% for calcifications and masses, respectively, while for the heterogeneous one this improvement was in the order of 33% for the masses and 17% for the calcifications. For different exposures, comparable image quality in terms of signal-difference-to-noise ratio and higher contrast for all features was obtained when using a monochromatic 19 keV beam at a lower mean glandular dose, compared to the polychromatic one. Monochromatic images also provide better detail and, in combination with BT, can lead to substantial improvement in visualization of features, and particularly better edge detection of low-contrast masses. %O Times Cited: 1 0 1 %O ://WOS:000341379900015 %0 Journal Article %A Qin, Xulei %A Fei, Baowei %D 2014 %T Measuring myofiber orientations from high-frequency ultrasound images using multiscale decompositions %J Physics in Medicine and Biology %V 59 %N 14 %O Jul 21 %P 3907-3924 %O Measuring myofiber orientations from high-frequency ultrasound images using multiscale decompositions %O 0031-9155 %O 10.1088/0031-9155/59/14/3907 %O WOS:000338771300016 %X High-frequency ultrasound (HFU) has the ability to image both skeletal and cardiac muscles. The quantitative assessment of these myofiber orientations has a number of applications in both research and clinical examinations; however, difficulties arise due to the severe speckle noise contained in the HFU images. Thus, for the purpose of automatically measuring myofiber orientations from two-dimensional HFU images, we propose a two-step multiscale image decomposition method. It combines a nonlinear anisotropic diffusion filter and a coherence enhancing diffusion filter to extract myofibers. This method has been verified by ultrasound data from simulated phantoms, excised fiber phantoms, specimens of porcine hearts, and human skeletal muscles in vivo. The quantitative evaluations of both phantoms indicated that the myofiber measurements of our proposed method were more accurate than other methods. The myofiber orientations extracted from different layers of the porcine hearts matched the prediction of an established cardiac mode and demonstrated the feasibility of extracting cardiac myofiber orientations from HFU images ex vivo. Moreover, HFU also demonstrated the ability to measure myofiber orientations in vivo. %O Times Cited: 1 0 1 %O ://WOS:000338771300016 %0 Journal Article %A Wang, Dongsheng %A Fei, Baowei %A Halig, Luma V. %A Qin, Xulei %A Hu, Zhongliang %A Xu, Hong %A Wang, Yongqiang Andrew %A Chen, Zhengjia %A Kim, Sungjin %A Shin, Dong M. %A Chen, Zhuo %D 2014 %T Targeted Iron-Oxide Nanoparticle for Photodynamic Therapy and Imaging of Head and Neck Cancer %J Acs Nano %V 8 %N 7 %O Jul %P 6620-6632 %O Targeted Iron-Oxide Nanoparticle for Photodynamic Therapy and Imaging of Head and Neck Cancer %O 1936-0851 %O 10.1021/nn501652j %O WOS:000339463100016 %X Photodynamic therapy (PDT) is a highly specific anticancer treatment modality for various cancers, particularly for recurrent cancers that no longer respond to conventional anticancer therapies. PDT has been under development for decades, but light-associated toxicity limits its clinical applications. To reduce the toxicity of PDT, we recently developed a targeted nanoparticle (NP) platform that combines a second-generation PDT drug, Pc 4, with a cancer targeting ligand, and iron oxide (IO) NPs. Carboxyl functionalized IO NPs were first conjugated with a fibronectin-mimetic peptide (Fmp), which binds integrin beta 1. Then the PDT drug Pc 4 was successfully encapsulated into the ligand-conjugated IO NPs to generate Fmp-IO-Pc 4. Our study indicated that both nontargeted IO-Pc 4 and targeted Fmp-IO-Pc 4 NPs accumulated in xenograft tumors with higher concentrations than nonfomiulated Pc 4. As expected, both IO-Pc 4 and Fmp-IO-Pc 4 reduced the size of HNSCC xenograft tumors more effectively than free Pc 4. Using a 10-fold lower dose of Pc 4 than that reported in the literature, the targeted Fmp-IO-Pc 4 NPs demonstrated significantly greater inhibition of tumor growth than nontargeted IO-Pc 4 NPs. These results suggest that the delivery of a PDT agent Pc 4 by IO NPs can enhance treatment efficacy and reduce PDT drug dose. The targeted IO-Pc 4 NPs have great potential to serve as both a magnetic resonance imaging (MRI) agent and PDT drug in the clinic. %O Times Cited: 2 0 2 %O ://WOS:000339463100016