Fast Fourier transform-based analysis of renal masses on contrast-enhanced computed tomography images for grading of tumor

2017 ◽  
Author(s):  
Bino A. Varghese ◽  
Darryl H. Hwang ◽  
Steven Y. Cen ◽  
Bhushan B. Desai ◽  
Felix Y. Yap ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Renal Masses ◽  
Computed Tomography Images ◽  
Contrast Enhanced ◽  
Enhanced Computed Tomography ◽  
Contrast Enhanced Computed Tomography

scholarly journals e-ASPECTS software is non-inferior to neuroradiologists in applying the ASPECT score to computed tomography scans of acute ischemic stroke patients

2016 ◽  
Vol 12 (6) ◽  
pp. 615-622 ◽  
Author(s):  
Simon Nagel ◽  
Devesh Sinha ◽  
Diana Day ◽  
Wolfgang Reith ◽  
René Chapot ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Ischemic Stroke ◽  
Correlation Coefficients ◽  
Ground Truth ◽  
Stroke Patients ◽  
Computed Tomography Images ◽  
Contrast Enhanced ◽  
Enhanced Computed Tomography ◽  
Sensitivity Specificity ◽  
Contrast Enhanced Computed Tomography

Background The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is an established 10-point quantitative topographic computed tomography scan score to assess early ischemic changes. We performed a non-inferiority trial between the e-ASPECTS software and neuroradiologists in scoring ASPECTS on non-contrast enhanced computed tomography images of acute ischemic stroke patients. Methods In this multicenter study, e-ASPECTS and three independent neuroradiologists retrospectively and blindly assessed baseline non-contrast enhanced computed tomography images of 132 patients with acute anterior circulation ischemic stroke. Follow-up scans served as ground truth to determine the definite area of infarction. Sensitivity, specificity, and accuracy for region- and score-based analysis, receiver-operating characteristic curves, Bland-Altman plots and Matthews correlation coefficients relative to the ground truth were calculated and comparisons were made between neuroradiologists and different pre-specified e-ASPECTS operating points. The non-inferiority margin was set to 10% for both sensitivity and specificity on region-based analysis. Results In total 2640 (132 patients × 20 regions per patient) ASPECTS regions were scored. Mean time from onset to baseline computed tomography was 146 ± 124 min and median NIH Stroke Scale (NIHSS) was 11 (6–17, interquartile range). Median ASPECTS for ground truth on follow-up imaging was 8 (6.5–9, interquartile range). In the region-based analysis, two e-ASPECTS operating points (sensitivity, specificity, and accuracy of 44%, 93%, 87% and 44%, 91%, 85%) were statistically non-inferior to all three neuroradiologists (all p-values <0.003). Both Matthews correlation coefficients for e-ASPECTS were higher (0.36 and 0.34) than those of all neuroradiologists (0.32, 0.31, and 0.3). Conclusions e-ASPECTS was non-inferior to three neuroradiologists in scoring ASPECTS on non-contrast enhanced computed tomography images of acute stroke patients.

scholarly journals The ‘step-clipping’ method: a guide for identifying a previously bleeding colonic diverticulum

2020 ◽  
Vol 08 (01) ◽  
pp. E64-E69
Author(s):  
Hirosato Tamari ◽  
Taiki Aoyama ◽  
Kenjiro Shigita ◽  
Naoki Asayama ◽  
Akira Fukumoto ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Target Lesion ◽  
Diverticular Bleeding ◽  
Computed Tomography Images ◽  
Contrast Enhanced ◽  
Before And After ◽  
Colonic Diverticular Bleeding ◽  
Enhanced Computed Tomography ◽  
Short Time ◽  
Contrast Enhanced Computed Tomography

Abstract Background and study aims Unsatisfactory detectability of a previously bleeding diverticulum by colonoscopy results from difficulty in precisely locating the target lesion, even with presence of an extravasation on contrast-enhanced computed tomography (CECT). This study aimed to evaluate the usefulness of the step-clipping method to overcome this limitation. Patients and methods Step-clipping was indicated for patients with colonic diverticular bleeding and presence of extravasation on CECT, but with absence of active bleeding on subsequent colonoscopy. The target diverticulum was identified by comparing computed tomography images before and after step clipping, which provided a positional relationship between each clip and the target lesion. Results Based on data from 21 consecutive cases meeting our inclusion criteria (14 men and 7 women; mean age, 73.2 years), the target diverticulum was endoscopically identified in 20 cases (95 %), in a median time of 5 minutes, and successfully treated. No adverse events were observed with the step-clipping method. Conclusion Step-clipping provided easy guidance to the target site for treatment in a short time, despite spontaneous cessation of bleeding at the diverticulum.

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