Journal of biomedical graphics and computing最新文献

{"title":"Analysis of the specific vibration modes of goethite (α-FeOOH) by terahertz spectroscopy and calculations of the vibration frequencies of a single molecule using density functional theory","authors":"R. Hasegawa, T. Kimura, T. Tanabe, K. Nishihara, A. Taniyama, Y. Oyama","doi":"10.5430/JBGC.V8N1P29","DOIUrl":"https://doi.org/10.5430/JBGC.V8N1P29","url":null,"abstract":"Steel sheet with an insulator to prevent corrosion is used for various purposes including in building and car manufacture. Terahertz waves, for which insulators are highly permeable and metal surfaces are highly reflective, have been studied in order to establish a new inspection technology for these steel plates. In our previous research, spectroscopic measurements in the 1.0-4.0 THz range, generated by a GaP crystal, were carried out in order to collect information on the infrared activity of the metal corrosion products formed on Zn-Al hot-dip galvanized steel sheet. In the previous work, the infrared activity of Fe-based corrosion products was not examined. To examine these products, we conducted THz spectroscopy on goethite (α-FeOOH) in the range from 8.4 to 11.0 THz, generated by a GaSe crystal. The results of Attenuated Total Reflectance (ATR) FTIR spectral measurements and molecular vibration calculations were analyzed, on the basis of which the natural vibration modes of α-FeOOH in the THz frequency range were assigned.","PeriodicalId":89580,"journal":{"name":"Journal of biomedical graphics and computing","volume":"8 1","pages":"29"},"PeriodicalIF":0.0,"publicationDate":"2018-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5430/JBGC.V8N1P29","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41380188","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}

{"title":"Three-dimensional modeling and assessment of cardiac adipose tissue distribution.","authors":"J. Klingensmith, Saygin Sop, Mete Naz, María Fernandez-Del-Valle, H. F. Lee","doi":"10.5430/JBGC.V8N1P14","DOIUrl":"https://doi.org/10.5430/JBGC.V8N1P14","url":null,"abstract":"Objective: The layer of fat that accumulates around the heart, called cardiac adipose tissue (CAT), can influence the development of coronary disease and is indicative of cardiovascular risk. While volumetric assessment of magnetic resonance imaging (MRI) can quantify CAT, volume alone gives no information about its distribution across the myocardial surface, which may be an important factor in risk assessment. In this study, a three-dimensional (3D) modeling technique is developed and used to quantify the distribution of the CAT across the surface of the heart. Methods: Dixon MRI scans, which produce a registered 3D set of fat-only and water-only images, were acquired in 10 subjects for a study on exercise intervention. A previously developed segmentation algorithm was used to identify the heart and CAT. Extracted contours were used to build 3D models. Procrustes analysis was used to register the heart models and an iterative closest point algorithm was used to register and align the CAT models for calculation of CAT thickness. Rays were cast in directions specified by a spherical parameterization of elevation and azimuthal angles, and intersections of the ray with the CAT surface were used to calculate the thickness at each location. To evaluate the effects of the spherical parameterization on the thickness estimates, a set of synthetic models were created with increasing major-to-minor axis ratios. Results: Based on the validation in the synthetic models, the average error in CAT thickness ranged from 1.25% to 17.3% for increasing major-to-minor axis ratio. Conclusions: A process was developed, based on Dixon MRI data, to provide 3D models of the myocardial surface and the cardiac fat. The models can be used in future segmentation algorithm development and for studies on changes in cardiac fat as a result of various interventions.","PeriodicalId":89580,"journal":{"name":"Journal of biomedical graphics and computing","volume":"8 1","pages":"14"},"PeriodicalIF":0.0,"publicationDate":"2018-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5430/JBGC.V8N1P14","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46032824","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}

{"title":"Automated segmentation of cardiac adipose tissue in Dixon magnetic resonance images","authors":"J. Klingensmith, Addison L. Elliott, María Fernandez-Del-Valle, S. Mitra","doi":"10.5430/JBGC.V8N1P1","DOIUrl":"https://doi.org/10.5430/JBGC.V8N1P1","url":null,"abstract":"Objective: Increasing evidence suggests a strong link between excess cardiac adipose tissue (CAT) and the risk of a cardiovascular event. Multi-echo Dixon magnetic resonance imaging (MRI), providing fat-only and water-only images, is a useful tool for quantification but requires the segmentation of CAT from a large number of images. The intent of this study was to evaluate an automated technique for CAT segmentation from Dixon MRI by comparing the contours identified by the automated algorithm to those manually traced by an observer.  Methods: An automated segmentation algorithm, based on optimal thresholds and custom morphological processing, was applied to the registered fat-only and water-only images to identify CAT in the volume scans. CAT contours in 446 images, from 10 MRI scans, were selected for validation analysis. Cross-sectional area (CSA) and volume were computed and compared using Bland-Altman analysis. In addition, Hausdorff distance and Dice Similarity Coefficient (DSC) were used for assessment. Results: Linear regression analysis yielded correlation of R 2 = 0.381 for CSA and R 2 = 0.879 for volume. When compared to the observer, the computer algorithm under-estimated CSA by 27.5 ± 40.0% and volume by 26.4 ± 10.4%. The average bidirectional Hausdorff distance was 26.2 ± 16.0 mm while the average unidirectional Hausdorff distances were 24.5 ± 15.7 mm and 12.4 ± 11.7 mm. The average DSC was 0.561 ± 0.100. The time required for manual tracing was 15.84 ± 3.73 min and the time required for the computer algorithm was 2.81 ± 0.12 min. Conclusions: This study provided a technique, faster and less tedious than manual tracing ( p < 0.00001), for quantification of CAT in Dixon MRI data, demonstrating feasibility of this approach for cardiac risk stratification.","PeriodicalId":89580,"journal":{"name":"Journal of biomedical graphics and computing","volume":"8 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2017-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5430/JBGC.V8N1P1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49277434","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}

{"title":"A rare presentation of nutcracker syndrome and it’s vascular managment","authors":"Ahoury Nj, Salami Fatima Adéniké, N’dja Ange Patrick, C. Nicolas, K. N’zi","doi":"10.5430/jbgc.v7n1p13","DOIUrl":"https://doi.org/10.5430/jbgc.v7n1p13","url":null,"abstract":"Nutcracker syndrome includes all the symptoms associated with the narrowing of the left renal vein (LRV). That narrowing occurs between the aorta and the Superior Mesenteric Artery (anterior) or vertebra (posterior). The symptoms are various and not specific but the patient sometimes presents hematuria with or without left flank pain. We report a case on a 42 years old woman, who was suffering from left flank pain for a long time aggravated during and after each pregnancy. The diagnosis of nutcracker syndrome was initially omitted. Abdominal pelvic Angio CT and venography were performed. We placed a percutaneous stent in the narrowed portion of the renal vein. The result was successful.","PeriodicalId":89580,"journal":{"name":"Journal of biomedical graphics and computing","volume":"7 1","pages":"13"},"PeriodicalIF":0.0,"publicationDate":"2017-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5430/jbgc.v7n1p13","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45036294","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}

{"title":"3D printing of beta-amyloid protein deposits along capillary walls","authors":"S. S. Horowitz, P. Snyder","doi":"10.5430/JBGC.V7N1P8","DOIUrl":"https://doi.org/10.5430/JBGC.V7N1P8","url":null,"abstract":"Abnormally high levels of neocortical beta-amyloid protein (A+) reflect Alzheimer’s disease (AD) pathology in persons with clinical evidence of dementia or mild cognitive impairment (MCI). The abnormal aggregation of beta-amyloid protein in the brain neuropil may lead to either diffuse plaques and/or concentrated neuritic plaques, with the latter form of deposits often present in the vicinity of the cerebral microvasculature. The A protein, with its crystalline molecular structure, infiltrates the vessel walls and compromises the blood-brain barrier (BBB). The physical basis for this was elegantly shown by Meyer and colleagues, in a 2008 publication showing two-dimensional (2D) confocal laser scanning microscopic imaging of vascular A protein deposits in APP23 transgenic mice. These investigators showed accumulations of “tuft-life structures”, also referred to as “pompons” with protruding spikes on – and embedded within – microvessels. These pompons of beta-amyloid protein “consist of fibrillar structures, [and] can encircle and constrict capillaries, and are often associated with distortion of capillaries”. We were struck by both the heuristic value of the imaging of Meyer and colleagues, in explaining the root cause of both the amyloid-related alterations in the vascular bed, and depicting minute protein deposits that are both geometrically complex, seemingly delicate and fragile, and yet tenacious in their embedding within small vessel walls. We re-created these images with standard 3D printing technology (extruded plastic) for both educational/teaching and artistic purposes.","PeriodicalId":89580,"journal":{"name":"Journal of biomedical graphics and computing","volume":"7 1","pages":"8"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5430/JBGC.V7N1P8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42784440","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}

{"title":"Automated modification and fusion of voxel models to construct body phantoms with heterogeneous breast tissue: Application to MRI simulations.","authors":"Joseph V Rispoli,&nbsp;Steven M Wright,&nbsp;Craig R Malloy,&nbsp;Mary P McDougall","doi":"10.5430/jbgc.v7n1p1","DOIUrl":"https://doi.org/10.5430/jbgc.v7n1p1","url":null,"abstract":"<p><strong>Background: </strong>Human voxel models incorporating detailed anatomical features are vital tools for the computational evaluation of electromagnetic (EM) fields within the body. Besides whole-body human voxel models, phantoms representing smaller heterogeneous anatomical features are often employed; for example, localized breast voxel models incorporating fatty and fibroglandular tissues have been developed for a variety of EM applications including mammography simulation and dosimetry, magnetic resonance imaging (MRI), and ultra-wideband microwave imaging. However, considering wavelength effects, electromagnetic modeling of the breast at sub-microwave frequencies necessitates detailed breast phantoms in conjunction with whole-body voxel models.</p><p><strong>Methods: </strong>Heterogeneous breast phantoms are sized to fit within radiofrequency coil hardware, modified by voxel-wise extrusion, and fused to whole-body models using voxel-wise, tissue-dependent logical operators. To illustrate the utility of this method, finite-difference time-domain simulations are performed using a whole-body model integrated with a variety of available breast phantoms spanning the standard four tissue density classifications representing the majority of the population.</p><p><strong>Results: </strong>The software library uses a combination of voxel operations to seamlessly size, modify, and fuse eleven breast phantoms to whole-body voxel models. The software is publicly available on GitHub and is linked to the file exchange at MATLAB^® Central. Simulations confirm the proportions of fatty and fibroglandular tissues in breast phantoms have significant yet predictable implications on projected power deposition in tissue.</p><p><strong>Conclusions: </strong>Breast phantoms may be modified and fused to whole-body voxel models using the software presented in this work; user considerations for the open-source software and resultant phantoms are discussed. Furthermore, results indicate simulating breast models as predominantly fatty tissue can considerably underestimate the potential for tissue heating in women with substantial fibroglandular tissue.</p>","PeriodicalId":89580,"journal":{"name":"Journal of biomedical graphics and computing","volume":"7 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5430/jbgc.v7n1p1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35257852","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}

{"title":"Utility of cardiac computed tomography to identify arrhythmia substrates for ventricular tachycardia and sudden cardiac death","authors":"D. Lee, M. Budoff, M. Girsky","doi":"10.5430/JBGC.V6N2P31","DOIUrl":"https://doi.org/10.5430/JBGC.V6N2P31","url":null,"abstract":"Sudden cardiac death (SCD) is the leading cause of death in the U.S., and many of these events are attributable to malignant ventricular arrhythmias such as sustained ventricular tachycardia (VT). Most of the efforts to identify arrhythmia precipitants in these patients are based on imaging to look for myocardial or coronary artery disease. As advances in cardiac computed tomography (CCT) are made, it has demonstrated its usefulness in identifying structural intracardiac pathology and measuring parameters of cardiac anatomy and function. In this article we review the different etiologies of VT/SCD that are identifiable by CCT, and its potential usefulness in the workup for VT/SCD.","PeriodicalId":89580,"journal":{"name":"Journal of biomedical graphics and computing","volume":"6 1","pages":"31"},"PeriodicalIF":0.0,"publicationDate":"2016-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5430/JBGC.V6N2P31","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71216821","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}

{"title":"Critical values of mechanical stress and strain during traumatic cervical spinal cord injury: Clinical study with the use of Finite Element Modelling","authors":"M. Czyz, Tomasz Tykocki, G. Miękisiak, K. Ścigała, R. Będziński, W. Jarmundowicz","doi":"10.5430/JBGC.V6N2P22","DOIUrl":"https://doi.org/10.5430/JBGC.V6N2P22","url":null,"abstract":"Study design: Prospective case-control study. Objective: Aim of the study was to assess critical values of mechanical stress and strain in the cervical spinal cord based on the Finite Element Method (FEM) simulations of specified clinical cases. Summary of background data: The knowledge about the values and distribution of tension and deformation, which are noted at the moment of traumatic spinal cord injury (tSCI) may enable determination of the range of primary and secondary injury. Methods: Total of 28 patients after cervical spine (C-spine) injury were enrolled, 14 with neurological symptoms of tSCI (study group, SG) and 14 neurologically intact (control group, CG). Both groups were age and sex matched. A three-dimensional (3D) numerical model of the cervical spinal cord containing dura and pia matter together with denticulate ligament was created. The variable boundary conditions were established individually for each case and allowed to reconstruct the moment of the injury in computer environment. Factors differentiating between SG and CG were tested with multiple logistic regression model. The predictors of ASIA scale outcomes were evaluated in the ordinal multinomial probit regression model. Results: There were no correlations between age, sex and the level of injury and the values of stress and strain. The results in longitudinal axis (z), in stress (OR-6.3; 95%CI 3.94-8.78; p < .033) and strain (OR-7.8; 95%CI 3.03-10.19; p < .046) were the risk factors of neurological deficits after tSCI. The cut off value for stress was 8.1 kPa (sensitivity-85.7%; specificity-78.6%; AUC-0.819, p < .001), and for strain 0.0117 (sensitivity-92.9%; specificity-72.5%; AUC-0.645, p < .001). Results in the longitudinal axis (z), in stress and strain correspond with grading in ASIA scale. One grade change in ASIA scale correlates with the decrease in z axis by 4.01 kPa and 0.012 in stress and strain respectively. Conclusions: The severity of damage of osseous and ligament structures of the spine, significantly influences the range of the mechanical stress applied to the spinal cord. Neural tissue of the spinal cord is the most resistant to the mechanical stimulus acting in sagittal direction, distraction appears to be the most destructive component of the injury phenomenon.","PeriodicalId":89580,"journal":{"name":"Journal of biomedical graphics and computing","volume":"6 1","pages":"22"},"PeriodicalIF":0.0,"publicationDate":"2016-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5430/JBGC.V6N2P22","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71216793","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}

{"title":"Does size really matter? A retrospective analysis of donor renal volume and its effects on renal function in donors after donation","authors":"K. S. Lim, S. Tay, Martyn Gostelow, S. Fook-Chong, L. Ng","doi":"10.5430/JBGC.V6N2P14","DOIUrl":"https://doi.org/10.5430/JBGC.V6N2P14","url":null,"abstract":"Introduction: It has been postulated that renal volume should play a bigger role in selection of donor kidney apart from anatomy and that the larger kidney should be kept for the donor. We attempted to investigate the correlation between donor residual renal volume and post-transplant donor renal function up to 5 years post donation. Material and methods: Retrospective analysis was performed on all living related renal transplant at a tertiary institution from 2005-2013. Pre-operative renal volumes of donors were calculated using computer tomography (CT) images. Serum creatinine and creatinine clearance levels were collected at pre-operative, 6 months, 1 year, and 5 years post donation. Percentage residual renal volume was correlated against the percentage change in serum creatinine and creatinine clearance over the specified time points. Results: Eighty-four donors were analyzed and the left kidney was removed in all patients. Median age was 46 years (22-76), median pre-operative renal volume was 261 cm 3 (142–453) and median percentage of residual renal volume was 44% (29-55). Median serum creatinine at pre-operative, 6 months, 1 year, and 5 years were 65, 96, 99, and 91 μmol/L respectively. Median creatinine clearance at pre-operative, 6 months, 1 year and 5 years were 113, 76, 74 and 81 ml/min respectively. Serum creatinine trend showed improvement up to 5 years but creatinine clearance stabilized after 6 months. When compared against percentage residual renal volume, there were no significant correlations found with percentage change in serum creatinine and creatinine clearance over pre-operative, 6 months, 1 year or 5 years. Discussion: There is no association between donated renal volume and changes in serum creatinine or creatinine clearance. Size of the donated kidney does not matter.","PeriodicalId":89580,"journal":{"name":"Journal of biomedical graphics and computing","volume":"6 1","pages":"14"},"PeriodicalIF":0.0,"publicationDate":"2016-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71216624","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}

{"title":"Evaluation of magnetic field homogeneity using in-out signal cycle mapping in gradient recalled echo images of a mixed water/oil phantom as a rough indication for daily quality control","authors":"Y. Ishimori, H. Kawamura, M. Monma","doi":"10.5430/JBGC.V6N2P7","DOIUrl":"https://doi.org/10.5430/JBGC.V6N2P7","url":null,"abstract":"Objective: Magnetic field (B 0 ) homogeneity is important for the performance of a magnetic resonance imaging (MRI) system. Traditionally, B 0 homogeneity was measured using the spectral peak or phase-mapping methods. However, these procedures are not generally accessible to the MRI operator and are rarely performed routinely. This study proposes a novel method for measuring B 0 homogeneity that can be implemented in daily quality control (QC). Methods: When a uniformly mixed water/oil phantom was imaged using a gradient recalled echo (GRE) pulse sequence, the signal intensity dynamically changed with echo time (TE). From this, the resonant frequency was calculated with a simplex curve-fitting algorithm on a pixel-by-pixel basis. The standard deviation of resonant frequency (SD) was used as the index of B 0 homogeneity. The appropriate TE pattern and feasibility of B 0 homogeneity evaluation were examined. Results: Over seven TEs (choosing nominal in-phase, out-phase, and the midpoints of both) were required to measure stable SD in a 1.5-T scanner. As B 0 homogeneity worsened, the SD became larger at the off-center position. Although a positive correlation was observed with the width of the spectral peak obtained by the phase-difference method, the SD value was about 5 × 10 4 times greater. Therefore, SD can be used only as an index of B 0 homogeneity. Similar results were obtained using a 0.3-T scanner. A  map and SD can be obtained by acquiring several GRE images of a water/oil mixed phantom within a few minutes. Conclusions: In-out signal cycle mapping can be easily implemented for daily QC in all MRI scanners.","PeriodicalId":89580,"journal":{"name":"Journal of biomedical graphics and computing","volume":"6 1","pages":"7"},"PeriodicalIF":0.0,"publicationDate":"2016-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5430/JBGC.V6N2P7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71216530","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}