Pub Date : 2014-01-27DOI: 10.2174/1874347101408010008
T. Banno, R. Kato*, Ryota Hanaoka, Hokuto Akamatsu, K. Kaneko, H. Toyama
s: When performing endovascular aortic repair (EVAR) procedures, clinicians sometimes encounter cases in which the indications for EVAR are beyond the instruction for use (IFU). In EVAR, proximal neck fixation is the most important factor. This report describes several techniques and tips for EVAR in cases presenting with a difficult short neck or angled neck, especially when using the Gore Excluder. Endo-wedge techniques (EWT), including non-sheathassisted EWT with sheath-assisted strategies, are presented. We describe the scrum technique, which is a special procedure that is only feasible when using the Gore Excluder. In this technique, intentional wire bending around the proximal neck portion occurs by pushing from both sides of the guidewire. This technique is applicable in cases with a sharply angled neck. The scrum with EWT is a more precise strategy for cases with a short or angled neck. Other troublesome cases include limb occlusion caused by weak points in the Gore Excluder® body and legs. The very rare complication of stent-graft collapse is also reviewed.
{"title":"Technical Tips for Endovascular Aortic Repair Using the Gore Excluder Abdominal Stent-Graft: Endo-Wedge Technique and Scrum Technique","authors":"T. Banno, R. Kato*, Ryota Hanaoka, Hokuto Akamatsu, K. Kaneko, H. Toyama","doi":"10.2174/1874347101408010008","DOIUrl":"https://doi.org/10.2174/1874347101408010008","url":null,"abstract":"s: When performing endovascular aortic repair (EVAR) procedures, clinicians sometimes encounter cases in which the indications for EVAR are beyond the instruction for use (IFU). In EVAR, proximal neck fixation is the most important factor. This report describes several techniques and tips for EVAR in cases presenting with a difficult short neck or angled neck, especially when using the Gore Excluder. Endo-wedge techniques (EWT), including non-sheathassisted EWT with sheath-assisted strategies, are presented. We describe the scrum technique, which is a special procedure that is only feasible when using the Gore Excluder. In this technique, intentional wire bending around the proximal neck portion occurs by pushing from both sides of the guidewire. This technique is applicable in cases with a sharply angled neck. The scrum with EWT is a more precise strategy for cases with a short or angled neck. Other troublesome cases include limb occlusion caused by weak points in the Gore Excluder® body and legs. The very rare complication of stent-graft collapse is also reviewed.","PeriodicalId":90366,"journal":{"name":"The open medical imaging journal","volume":"30 1","pages":"8-21"},"PeriodicalIF":0.0,"publicationDate":"2014-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74562174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-23DOI: 10.2174/1874347101408010001
J. Frahm, Sebastian Schätz, Markus Untenberger, Shuo Zhang, Dirk Voit, K. Merboldt, J. Sohns, J. Lotz, M. Uecker
Purpose: To evaluate the temporal accuracy of a self-consistent nonlinear inverse reconstruction method (NLINV) for real-time MRI using highly undersampled radial gradient-echo sequences and to present an open source framework for the motion assessment of real-time MRI methods. Methods: Serial image reconstructions by NLINV combine a joint estimation of individual frames and corresponding coil sensitivities with temporal regularization to a preceding frame. The temporal fidelity of the method was determined with a phantom consisting of water-filled tubes rotating at defined angular velocity. The conditions tested correspond to real- time cardiac MRI using SSFP contrast at 1.5 T (40 ms resolution) and T1 contrast at 3.0 T (33 ms and 18 ms resolution). In addition, the performance of a post-processing temporal median filter was evaluated. Results: NLINV reconstructions without temporal filtering yield accurate estimations as long as the speed of a small moving object corresponds to a spatial displacement during the acquisition of a single frame which is smaller than the object itself. Faster movements may lead to geometric distortions. For small objects moving at high velocity, a median filter may severely compromise the spatiotemporal accuracy. Conclusion: NLINV reconstructions offer excellent temporal fidelity as long as the image acquisition time is short enough to adequately sample ("freeze") the object movement. Temporal filtering should be applied with caution. The motion framework emerges as a valuable tool for the evaluation of real-time MRI methods.
目的:利用高度欠采样的径向梯度回波序列评估实时MRI自洽非线性逆重建方法(NLINV)的时间精度，并为实时MRI方法的运动评估提供一个开源框架。方法:利用NLINV方法对序列图像进行重建，将单个帧和相应线圈灵敏度的联合估计与前一帧的时间正则化相结合。该方法的时间保真度是用一个由以规定角速度旋转的装满水的管组成的幻影来确定的。所测试的条件对应于实时心脏MRI，使用1.5 T (40 ms分辨率)的SSFP对比度和3.0 T (33 ms和18 ms分辨率)的T1对比度。此外，还对后处理时间中值滤波器的性能进行了评价。结果:在获取比物体本身小的单帧图像时，只要运动物体的速度对应于空间位移，没有时间滤波的NLINV重建就能得到准确的估计。更快的运动可能导致几何扭曲。对于高速运动的小物体，中值滤波会严重影响其时空精度。结论:只要图像采集时间足够短，足以充分采样(“冻结”)物体运动，NLINV重建就能提供出色的时间保真度。时间过滤应该谨慎使用。运动框架成为评估实时MRI方法的一个有价值的工具。
{"title":"On the temporal fidelity of nonlinear inverse reconstructions for real- time MRI – The motion challenge.","authors":"J. Frahm, Sebastian Schätz, Markus Untenberger, Shuo Zhang, Dirk Voit, K. Merboldt, J. Sohns, J. Lotz, M. Uecker","doi":"10.2174/1874347101408010001","DOIUrl":"https://doi.org/10.2174/1874347101408010001","url":null,"abstract":"Purpose: To evaluate the temporal accuracy of a self-consistent nonlinear inverse reconstruction method (NLINV) for real-time MRI using highly undersampled radial gradient-echo sequences and to present an open source framework for the motion assessment of real-time MRI methods. Methods: Serial image reconstructions by NLINV combine a joint estimation of individual frames and corresponding coil sensitivities with temporal regularization to a preceding frame. The temporal fidelity of the method was determined with a phantom consisting of water-filled tubes rotating at defined angular velocity. The conditions tested correspond to real- time cardiac MRI using SSFP contrast at 1.5 T (40 ms resolution) and T1 contrast at 3.0 T (33 ms and 18 ms resolution). In addition, the performance of a post-processing temporal median filter was evaluated. Results: NLINV reconstructions without temporal filtering yield accurate estimations as long as the speed of a small moving object corresponds to a spatial displacement during the acquisition of a single frame which is smaller than the object itself. Faster movements may lead to geometric distortions. For small objects moving at high velocity, a median filter may severely compromise the spatiotemporal accuracy. Conclusion: NLINV reconstructions offer excellent temporal fidelity as long as the image acquisition time is short enough to adequately sample (\"freeze\") the object movement. Temporal filtering should be applied with caution. The motion framework emerges as a valuable tool for the evaluation of real-time MRI methods.","PeriodicalId":90366,"journal":{"name":"The open medical imaging journal","volume":"56 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2014-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80690259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-31DOI: 10.2174/1874347101307010019
Peter C Marks, Marilena Preda, Terry Henderson, Lucy Liaw, Volkhard Lindner, Robert E Friesel, Ilka M Pinz
The quantitative analysis of blood vessel volumes from magnetic resonance angiograms (MRA) or μCT images is difficult and time-consuming. This fact, when combined with a study that involves multiple scans of multiple subjects, can represent a significant portion of research time. In order to enhance analysis options and to provide an automated and fast analysis method, we developed a software plugin for the ImageJ and Fiji image processing frameworks that enables the quick and reproducible volume quantification of blood vessel segments. The novel plugin named Volume Calculator (VolCal), accepts any binary (thresholded) image and produces a three-dimensional schematic representation of the vasculature that can be directly manipulated by the investigator. Using MRAs of the mouse hindlimb ischemia model, we demonstrate quick and reproducible blood vessel volume calculations with 95 - 98% accuracy. In clinical settings this software may enhance image interpretation and the speed of data analysis and thus enhance intervention decisions for example in peripheral vascular disease or aneurysms. In summary, we provide a novel, fast and interactive quantification of blood vessel volumes for single blood vessels or sets of vessel segments with particular focus on collateral formation after an ischemic insult.
{"title":"Interactive 3D Analysis of Blood Vessel Trees and Collateral Vessel Volumes in Magnetic Resonance Angiograms in the Mouse Ischemic Hindlimb Model.","authors":"Peter C Marks, Marilena Preda, Terry Henderson, Lucy Liaw, Volkhard Lindner, Robert E Friesel, Ilka M Pinz","doi":"10.2174/1874347101307010019","DOIUrl":"https://doi.org/10.2174/1874347101307010019","url":null,"abstract":"<p><p>The quantitative analysis of blood vessel volumes from magnetic resonance angiograms (MRA) or μCT images is difficult and time-consuming. This fact, when combined with a study that involves multiple scans of multiple subjects, can represent a significant portion of research time. In order to enhance analysis options and to provide an automated and fast analysis method, we developed a software plugin for the ImageJ and Fiji image processing frameworks that enables the quick and reproducible volume quantification of blood vessel segments. The novel plugin named Volume Calculator (VolCal), accepts any binary (thresholded) image and produces a three-dimensional schematic representation of the vasculature that can be directly manipulated by the investigator. Using MRAs of the mouse hindlimb ischemia model, we demonstrate quick and reproducible blood vessel volume calculations with 95 - 98% accuracy. In clinical settings this software may enhance image interpretation and the speed of data analysis and thus enhance intervention decisions for example in peripheral vascular disease or aneurysms. In summary, we provide a novel, fast and interactive quantification of blood vessel volumes for single blood vessels or sets of vessel segments with particular focus on collateral formation after an ischemic insult.</p>","PeriodicalId":90366,"journal":{"name":"The open medical imaging journal","volume":"7 ","pages":"19-27"},"PeriodicalIF":0.0,"publicationDate":"2013-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3929959/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32150733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-09-27DOI: 10.2174/1874347101307010009
A. Al-Fahoum, B. Harb
In this paper, a combined Fractal and Wavelet (CFW) compression algorithm targeting x-ray angiogram images is proposed. Initially, the image is decomposed using wavelet transform. The smoothness of the low frequency part of the image appears as an approximation image with higher self similarities, therefore, it is coded using a fractal coding technique. However, the rest of the image is coded using an adaptive wavelet thresholding technique. This model is implemented and its performance is compared with best performances of the available published algorithms. A data set containing 1000 x-ray angiograms is used to study the performance of the algorithm. A minimum compression ratio of 30 with a peak signal to noise ratio (PSNR) of 36 dB and percent diameter stenosis deviation of (<0.2%) was achieved. Results demonstrate the effectiveness of the proposed technique in obtaining a diagnostic quality of reconstructed images at very low bit rates.
{"title":"A Combined Fractal and Wavelet Angiography Image Compression Approach","authors":"A. Al-Fahoum, B. Harb","doi":"10.2174/1874347101307010009","DOIUrl":"https://doi.org/10.2174/1874347101307010009","url":null,"abstract":"In this paper, a combined Fractal and Wavelet (CFW) compression algorithm targeting x-ray angiogram images is proposed. Initially, the image is decomposed using wavelet transform. The smoothness of the low frequency part of the image appears as an approximation image with higher self similarities, therefore, it is coded using a fractal coding technique. However, the rest of the image is coded using an adaptive wavelet thresholding technique. This model is implemented and its performance is compared with best performances of the available published algorithms. A data set containing 1000 x-ray angiograms is used to study the performance of the algorithm. A minimum compression ratio of 30 with a peak signal to noise ratio (PSNR) of 36 dB and percent diameter stenosis deviation of (<0.2%) was achieved. Results demonstrate the effectiveness of the proposed technique in obtaining a diagnostic quality of reconstructed images at very low bit rates.","PeriodicalId":90366,"journal":{"name":"The open medical imaging journal","volume":"97 1","pages":"9-18"},"PeriodicalIF":0.0,"publicationDate":"2013-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74697640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-02-07DOI: 10.2174/1874347101307010001
Yufang Bao, A. Maudsley
In this paper, a polynomial fitting improved Bayesian approach is proposed for the reconstruction of volumetric metabolite images from long echo time (TE) whole brain proton magnetic resonance spectroscopic imaging (MRSI) data. The proposed algorithm uses a modified EM (expectation maximization) algorithm that takes into account the partial vol- ume effects contained inside a thick slice MRSI. It incorporates high resolution volumetric magnetic resonance imaging (MRI) as a priori information. It further integrates the polynomial fitting method to smooth out artificial edges before the high resolution metabolite images are reconstructed. Our proposed reconstruction method has successfully extended our existing reconstruction of two dimensional (2D) metabolite images to 3D cases. The experimental results show that reso- lution enhanced volumetric metabolite images are reconstructed.
{"title":"A Polynomial Fitting Improved Bayesian Reconstruction Method for Whole Brain Volumetric MRSI Metabolite Images","authors":"Yufang Bao, A. Maudsley","doi":"10.2174/1874347101307010001","DOIUrl":"https://doi.org/10.2174/1874347101307010001","url":null,"abstract":"In this paper, a polynomial fitting improved Bayesian approach is proposed for the reconstruction of volumetric metabolite images from long echo time (TE) whole brain proton magnetic resonance spectroscopic imaging (MRSI) data. The proposed algorithm uses a modified EM (expectation maximization) algorithm that takes into account the partial vol- ume effects contained inside a thick slice MRSI. It incorporates high resolution volumetric magnetic resonance imaging (MRI) as a priori information. It further integrates the polynomial fitting method to smooth out artificial edges before the high resolution metabolite images are reconstructed. Our proposed reconstruction method has successfully extended our existing reconstruction of two dimensional (2D) metabolite images to 3D cases. The experimental results show that reso- lution enhanced volumetric metabolite images are reconstructed.","PeriodicalId":90366,"journal":{"name":"The open medical imaging journal","volume":"460 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2013-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82976905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-12-14DOI: 10.2174/1874347101206010108
Belzunce Ma, Verrastro Ca, E. Venialgo, Cohen Im
Although the use of iterative algorithms for image reconstruction in 3D Positron Emission Tomography (PET) has shown to produce images with better quality than analytical methods, they are computationally expensive. New Graphic Processor Units (GPUs) provide high performance at low cost and programming tools that make it possible to execute parallel algorithms in scientific applications. In this work, a GPU parallel implementation of the iterative reconstruction algorithm MLEM 3D has been developed using CUDA, a parallel model from NVIDIA. The Siddon algorithm was used as Projector and Backprojector. Acceleration factors up to 85 times were achieved, with respect to a single thread CPU implementation. The performance in GPU with Tesla and Fermi, which are respectively the first and the last generation of CUDA compatible architectures, has been compared. The image quality in each platform has been analyzed, showing a higher level of noise in GPU, due to race condition problems. The new features of Fermi architecture permitted to solve this problem using atomic operations.
{"title":"Cuda Parallel Implementation of Image Reconstruction Algorithm for Positron Emission Tomography","authors":"Belzunce Ma, Verrastro Ca, E. Venialgo, Cohen Im","doi":"10.2174/1874347101206010108","DOIUrl":"https://doi.org/10.2174/1874347101206010108","url":null,"abstract":"Although the use of iterative algorithms for image reconstruction in 3D Positron Emission Tomography (PET) has shown to produce images with better quality than analytical methods, they are computationally expensive. New Graphic Processor Units (GPUs) provide high performance at low cost and programming tools that make it possible to execute parallel algorithms in scientific applications. In this work, a GPU parallel implementation of the iterative reconstruction algorithm MLEM 3D has been developed using CUDA, a parallel model from NVIDIA. The Siddon algorithm was used as Projector and Backprojector. Acceleration factors up to 85 times were achieved, with respect to a single thread CPU implementation. The performance in GPU with Tesla and Fermi, which are respectively the first and the last generation of CUDA compatible architectures, has been compared. The image quality in each platform has been analyzed, showing a higher level of noise in GPU, due to race condition problems. The new features of Fermi architecture permitted to solve this problem using atomic operations.","PeriodicalId":90366,"journal":{"name":"The open medical imaging journal","volume":"68 1","pages":"108-118"},"PeriodicalIF":0.0,"publicationDate":"2012-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76423685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-10-05DOI: 10.2174/1874347101206010103
Y. Oie, K. Murayama, S. Nagahisa, M. Abe, H. Toyama, K. Katada
A 77-year-old woman presented with worsening cognitive impairment, nausea and vomiting. Computed tomography (CT) of the head revealed a high-density mass that symmetrically filled both lateral ventricles. Magnetic resonance imaging (MRI) showed an enhanced mass with T1 and T2 prolongation and restricted diffusion on diffusion weighted imaging (DWI). Diagnosis was delayed until a post-mortem examination, which revealed the mass as a primary central nervous system lymphoma (PCNSL). A high-intensity tumor on DWI with lateral ventricle involvement should raise the possibility of PCNSL.
{"title":"Primary Central Nervous System Lymphoma with Lateral Ventricle Involvement","authors":"Y. Oie, K. Murayama, S. Nagahisa, M. Abe, H. Toyama, K. Katada","doi":"10.2174/1874347101206010103","DOIUrl":"https://doi.org/10.2174/1874347101206010103","url":null,"abstract":"A 77-year-old woman presented with worsening cognitive impairment, nausea and vomiting. Computed tomography (CT) of the head revealed a high-density mass that symmetrically filled both lateral ventricles. Magnetic resonance imaging (MRI) showed an enhanced mass with T1 and T2 prolongation and restricted diffusion on diffusion weighted imaging (DWI). Diagnosis was delayed until a post-mortem examination, which revealed the mass as a primary central nervous system lymphoma (PCNSL). A high-intensity tumor on DWI with lateral ventricle involvement should raise the possibility of PCNSL.","PeriodicalId":90366,"journal":{"name":"The open medical imaging journal","volume":"232 1","pages":"103-107"},"PeriodicalIF":0.0,"publicationDate":"2012-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82751798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-08-08DOI: 10.2174/1874347101206010097
M. Cordes, P. Kondrat, Karen Horstrup, T. Kuwert, M. Sasiadek
Background: Epidemiologic data revealed an increasing incidence of papillary carcinomas (PTCs) in the German population. There is some evidence that the size of resected PTCs has decreased during the last few years. Purpose: The aim of the present study was to test the hypothesis that the sonographic characteristics of PTCs vary with size. Material/Methods: Consecutive PTCs were histologically confirmed in 41 patients. Ultrasound examinations of these 50 PTCs were reevaluated retrospectively and classified according to five sonographic criteria. Results: It could be shown that the sonographic shape (p < 0.001), the contour (p = 0.024), the structure (p = 0.04), the echogenicity (p < 0.001) and calcifications (p = 0.008) varied with the size of the neoplasms. By factoranalysis a factor FPTC with an eigenvalue of 1.89 could be extracted from the data on which the sonographic structure, the ontour and the presence of calcifications had the strongest impact with factorloadings of 0.74, 0.68 and 0.61, respectively. Conclusion: The knowledge of the variation of the ultrasound characteristics should be of assistance for the sonographic classification of PTCs. In this context microcarcinomas usually do not display cystic components. However, they may show microcalcifications. Cystic components, hyperechogenicity and the taller-than-wide sign are predominantly seen in larger PTCs.
{"title":"Size Dependent Ultrasound Characteristics in Histologically Confirmed Papillary Thyroid Carcinomas: A Multivariate Analysis","authors":"M. Cordes, P. Kondrat, Karen Horstrup, T. Kuwert, M. Sasiadek","doi":"10.2174/1874347101206010097","DOIUrl":"https://doi.org/10.2174/1874347101206010097","url":null,"abstract":"Background: Epidemiologic data revealed an increasing incidence of papillary carcinomas (PTCs) in the German population. There is some evidence that the size of resected PTCs has decreased during the last few years. Purpose: The aim of the present study was to test the hypothesis that the sonographic characteristics of PTCs vary with size. Material/Methods: Consecutive PTCs were histologically confirmed in 41 patients. Ultrasound examinations of these 50 PTCs were reevaluated retrospectively and classified according to five sonographic criteria. Results: It could be shown that the sonographic shape (p < 0.001), the contour (p = 0.024), the structure (p = 0.04), the echogenicity (p < 0.001) and calcifications (p = 0.008) varied with the size of the neoplasms. By factoranalysis a factor FPTC with an eigenvalue of 1.89 could be extracted from the data on which the sonographic structure, the ontour and the presence of calcifications had the strongest impact with factorloadings of 0.74, 0.68 and 0.61, respectively. Conclusion: The knowledge of the variation of the ultrasound characteristics should be of assistance for the sonographic classification of PTCs. In this context microcarcinomas usually do not display cystic components. However, they may show microcalcifications. Cystic components, hyperechogenicity and the taller-than-wide sign are predominantly seen in larger PTCs.","PeriodicalId":90366,"journal":{"name":"The open medical imaging journal","volume":"39 1","pages":"97-102"},"PeriodicalIF":0.0,"publicationDate":"2012-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80515487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-06-01DOI: 10.2174/1874347101206010080
Zhexing Liu, Mahshid Farzinfar, L. Katz, Hongtu Zhu, C. Goodlett, G. Gerig, M. Styner, B. Marks
Diffusion Tensor Imaging (DTI) has become a widely used MR modality to investigate white matter integrity in the brain. This paper presents the application of an automated method for voxel-wise group comparisons of DTI images in a study of fitness and aging. The automated processing method consists of 3 steps: 1) preprocessing including image format converting, image quality control, eddy-current and motion artifact correction, skull stripping and tensor image estimation, 2) study-specific unbiased DTI atlas computation via diffeomorphic fluid-based and demons deformable registration and 3) voxel-wise statistical analysis via heterogeneous linear regression and a wild bootstrap technique for correcting for multiple comparisons. Our results show that this fully automated method is suitable for voxel-wise group DTI analysis. Furthermore, in older adults, the results suggest a strong link between reduced fractional anisotropy (FA) values, fitness and aging.
{"title":"Automated Voxel-Wise Brain DTI Analysis of Fitness and Aging","authors":"Zhexing Liu, Mahshid Farzinfar, L. Katz, Hongtu Zhu, C. Goodlett, G. Gerig, M. Styner, B. Marks","doi":"10.2174/1874347101206010080","DOIUrl":"https://doi.org/10.2174/1874347101206010080","url":null,"abstract":"Diffusion Tensor Imaging (DTI) has become a widely used MR modality to investigate white matter integrity in the brain. This paper presents the application of an automated method for voxel-wise group comparisons of DTI images in a study of fitness and aging. The automated processing method consists of 3 steps: 1) preprocessing including image format converting, image quality control, eddy-current and motion artifact correction, skull stripping and tensor image estimation, 2) study-specific unbiased DTI atlas computation via diffeomorphic fluid-based and demons deformable registration and 3) voxel-wise statistical analysis via heterogeneous linear regression and a wild bootstrap technique for correcting for multiple comparisons. Our results show that this fully automated method is suitable for voxel-wise group DTI analysis. Furthermore, in older adults, the results suggest a strong link between reduced fractional anisotropy (FA) values, fitness and aging.","PeriodicalId":90366,"journal":{"name":"The open medical imaging journal","volume":"70 ","pages":"80-88"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72549394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-06-01DOI: 10.2174/1874347101206010089
K. Ejiri, K. Minami, H. Toyama, Gen Kudo, Hidekazu Hattori, N. Kobayashi, Masaki Kato, Masanobu Ishiguro, H. Fujii, M. Kuroda, T. Utsumi, K. Iwase, K. Katada
Purpose: The incident at the Fukushima Daiichi nuclear power station in 2011 has again raised concerns with the public regarding radiation exposure, especially so in medical workers and patients undergoing treatment involving the use of radiation. Radioisotopes are currently used during sentinel node navigation surgery (SNNS) in operating rooms without radiation monitoring. To re-evaluate the safety issues, the potential effective dose (Epoten) from 99m Tc-tin (-Sn) colloid in breast cancer surgery was estimated and personal dose equivalents, Hp(10) and Hp(0.07), were measured during SNNS. Materials and methods: Seventeen breast cancer patients were enrolled. One day before SNNS, 99m Tc-Sn colloid was injected around the tumor and radiation exposure rates were measured using survey meters. Personal dose equivalents for the surgical workers were measured. Hp(10) and Hp(0.07) for the body and Hp(0.07) for the hands were recorded using semiconductor detectors and ring-type glass dosimeters. Results: The maximum Epoten was 29 μSv per 74 MBq injection. The maximum Hp(10) for the primary and assisting surgeons, nurse, and anesthetist was 3.7, 1.4, 0.3 and 0.6 μSv per SNNS, respectively. The maximum Hp(0.07) for the hands was 100 μSv. Maximum radiocontamination 20 times higher than background (0.05 μSv/h) was detected in bloody gauze. Conclusion: The workers' radiation dose exposure from SNNS was not high, although radiation management such as a temporary cooling off period may be required.
{"title":"Sentinel node navigation surgery with 99mTc-tin colloid in breast cancer: Radiation safety considerations","authors":"K. Ejiri, K. Minami, H. Toyama, Gen Kudo, Hidekazu Hattori, N. Kobayashi, Masaki Kato, Masanobu Ishiguro, H. Fujii, M. Kuroda, T. Utsumi, K. Iwase, K. Katada","doi":"10.2174/1874347101206010089","DOIUrl":"https://doi.org/10.2174/1874347101206010089","url":null,"abstract":"Purpose: The incident at the Fukushima Daiichi nuclear power station in 2011 has again raised concerns with the public regarding radiation exposure, especially so in medical workers and patients undergoing treatment involving the use of radiation. Radioisotopes are currently used during sentinel node navigation surgery (SNNS) in operating rooms without radiation monitoring. To re-evaluate the safety issues, the potential effective dose (Epoten) from 99m Tc-tin (-Sn) colloid in breast cancer surgery was estimated and personal dose equivalents, Hp(10) and Hp(0.07), were measured during SNNS. Materials and methods: Seventeen breast cancer patients were enrolled. One day before SNNS, 99m Tc-Sn colloid was injected around the tumor and radiation exposure rates were measured using survey meters. Personal dose equivalents for the surgical workers were measured. Hp(10) and Hp(0.07) for the body and Hp(0.07) for the hands were recorded using semiconductor detectors and ring-type glass dosimeters. Results: The maximum Epoten was 29 μSv per 74 MBq injection. The maximum Hp(10) for the primary and assisting surgeons, nurse, and anesthetist was 3.7, 1.4, 0.3 and 0.6 μSv per SNNS, respectively. The maximum Hp(0.07) for the hands was 100 μSv. Maximum radiocontamination 20 times higher than background (0.05 μSv/h) was detected in bloody gauze. Conclusion: The workers' radiation dose exposure from SNNS was not high, although radiation management such as a temporary cooling off period may be required.","PeriodicalId":90366,"journal":{"name":"The open medical imaging journal","volume":"6 1","pages":"89-96"},"PeriodicalIF":0.0,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81239454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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