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A novel alignment procedure to assess calcified coronary plaques in histopathology, post-mortem computed tomography angiography and optical coherence tomography
摘要： Purpose: Improve mapping and registration of longitudinal view on histopathology vessels in a three-dimensional alignment procedure for postmortem quantitative coronary plaque analyses. This new procedure is applied and results shown using calcified coronary plaque analyses within post-mortem computed tomography angiography (PMCTA), optical coherence tomography (OCT) and the gold standard of histopathology. Results: In total, 338 annotated histopathology images were included, 166 PMCTA transversal images and 285 OCT images were aligned in the comparison. The results from the comparison using the alignment procedure showed overall that the calcified plaques seem to be overestimated by PMCTA and underestimated by OCT. Conclusions: The 3D fusion approach, aligning the images of PMCTA, OCT and histopathology as gold standard allowed for a slice-based comparison of the different modalities. The results showed that PMCTA overestimates the calcified plaques while OCT underestimates these, compared to histopathology.
关键词： Alignment,Calcified coronary plaques,Histopathology,Optical coherence tomography,Postmortem-computed tomography angiography
更新于2025-09-23 15:23:52
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Value of a smartphone-compatible thermal imaging camera in the detection of peroneal artery perforators: Comparative study with computed tomography angiography
摘要： Background: The aim of this study was to investigate the value of a smartphone-compatible thermal imaging camera in the mapping of the peroneal artery perforators. Methods: Twelve consecutive patients scheduled for fibular flap reconstruction were enrolled. The lower limbs were first studied using smartphone-based dynamic infrared thermography (DIRT). During the rewarming, the hotspots were marked, small rubber markers were taped to the registered sites, and then the patients were sent for a CT scan. The diagnostic performance of smartphone-based DIRT was evaluated by comparing the DIRT findings with CT angiography and intraoperative findings. Results: DIRT detected 42 of the 57 dominant perforators in 24 limbs and resulted in a sensitivity of 73.7% and a positive predictive value of 65.6%. Conclusions: The sensitivity and positive predictive value of the smartphone-based DIRT are low. Currently, it should be used as an adjunctive tool together with the established imaging techniques.
关键词： thermography,fibular flap,perforator mapping,peroneal artery perforator flap,computed tomography angiography
更新于2025-09-23 15:23:52
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Implementation of multiphase computed tomography angiography in management of patients with acute ischemic stroke in clinical practice
摘要： Multiphase computed tomography angiography (CTA) provides information on the status of major cranial arteries and extent of brain collateralization. The purpose of the study was to determine whether implementation of multiphase CTA in routine clinical practice was feasible, safe and useful. Patients with acute ischemic stroke (NIHSS (cid:1) 6) were included. Multiphase CTA was performed. Duration of performing multiphase CTA, inter-rater correlation and incidence of contrast-induced nephropathy (CIN) were studied. Infarct volume, incidence of hemorrhagic transformation, the rates of favorable outcome and death were compared between those with poor and intermediate-good collateralization. Multiphase CTA was performed in 108 patients. Mean duration on each multiphase CTA study was 4.8 min. Inter-rater reliability was intermediate-good (weighted kappa 0.7569, p < 0.001). CIN occurred in 3 patients (2.8%). There were no major intracranial/extracranial artery occlusion in 31 patients (29%) and there were severe stenosis or occlusions in 77 patients (71%). In the subgroup of patients with major artery severe stenosis or occlusion, 36 patients (36/77, 47%) had poor collateralization. Despite non-signi?cant difference in acute treatment, the patients with poor collateralization had larger infarct (123 vs 35 cc, p < 0.001) and poorer outcomes (mean modi?ed Rankin scale 3.86 vs 2.73, p = 0.011), while the differences in symptomatic hemorrhagic transformation (2.6 vs 7%, p = 0.385) and death rate (14 vs 12%, p = 0.825) were non-signi?cant, as compared to those with intermediate-good collateralization. Multiphase CTA was feasible and safe. Besides the status of major arteries, multiphase CTA provided information on collateralization, which was associated with the size of infarct and clinical outcomes.
关键词： Multiphase CTA,Asian,Thai,Acute stroke,Computed tomography angiography,Ischemic stroke
更新于2025-09-23 15:23:52
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Common venous renal trunk in two dogs: Multidetector computed tomographic imaging findings
摘要： In dogs, variation in the branching pattern of renal veins is rare with only few patterns reported. This report describes two unusual anomalies of the renal vein branching patterns in two dogs. In dog 1, a common renal trunk drained both kidneys, in a T-shape pattern, in the caudal vena cava after a long right perirenal course. In dog 2, a common venous trunk branched cranially from the pre-renal segment of an azygos-caudal vena cava venous trunk and divided into the renal veins in a Y-shape pattern. Proper knowledge of the possible anatomical variations in renal venous drainage may be helpful during imaging assessment and surgical planning of several canine diseases involving the abdominal vasculature and retroperitoneal space.
关键词： renal veins,caudal vena cava,gonadal veins,dog,computed tomography,angiography
更新于2025-09-23 15:22:29
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Submillisievert CT angiography for carotid arteries using wide array CT scanner and latest iterative reconstruction algorithm in comparison with previous generations technologies: Feasibility and diagnostic accuracy
摘要： Objectives: To assess evaluability and diagnostic accuracy of a low dose CT angiography (CTA) protocol for carotid arteries using latest Iterative Reconstruction (IR) algorithm in comparison with standard 100 kVp protocol using previous generation CT and IR. Materials and Methods: 105 patients, referred for CTA of the carotid arteries were prospectively enrolled in our study and underwent CTA with 80 kVp and latest IR algorithm (group 1). Data were retrospectively compared with 100 consecutive patients with similar examination indications that had previously undergone CTA of carotid arteries with a standard 100 kVp protocol and a first generation IR algorithm (group 2). Image quality was evaluated with a 4-point Likert-scale. For each exam CT number, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) at level of common carotid artery (CCA), internal carotid artery (ICA) and at level of Circle of Willis and Effective Dose (ED) were evaluated. 62 Group 1 patients underwent a clinically indicated DSA and results were compared with CTA. Results: No exams reported as not diagnostic. The overall mean CT number value of all arterial segments was above 450 HU in both groups. Significant lower noise, and higher SNR and CNR values were found in group 1 in comparison with group 2 despite the use of 80 kVp. In 62-group 1 patients studied by DSA, CTA showed in a segment-based analysis a sensitivity, negative predictive value and accuracy of 100%, 100% and 99% respectively. Mean ED in group 1 was 0.54±0.1 mSv with a dose reduction up to 86%. Conclusions: CTA for carotid arteries using latest IR algorithm allows to perform exams with submillisievert radiation exposure maintaining good image quality, overall evaluability and diagnostic accuracy.
关键词： atherosclerosis,Carotid arteries,Computed Tomography Angiography,Iterative reconstruction algorithm.,dose reduction
更新于2025-09-23 15:22:29
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Radiation dose and image quality in intraoperative CT (iCT) angiography of the brain with stereotactic head frames
摘要： Objectives Intraoperative CT (iCT) angiography of the brain with stereotactic frames is an integral part of navigated neurosurgery. Validated data regarding radiation dose and image quality in these special examinations are not available. We therefore investigated two iCT protocols in this IRB-approved study. Methods Retrospective analysis of patients, who received a cerebral stereotactic iCT angiography on a 128 slice CT scanner between February 2016 and December 2017. In group A, automated tube current modulation (ATCM; reference value 410 mAs) and automated tube voltage selection (reference value 120 kV) were enabled, and only examinations with a selected voltage of 120 kV were included. In group B, fixed parameters were applied (300 mAs, 120 kV). Radiation dose was measured by assessing the volumetric CT dose index (CTDIvol), dose length product (DLP) and effective dose (ED). Signal-to-noise ratio (SNR) and image noise were assessed for objective image quality, visibility of arteries and grey-white differentiation for subjective image quality. Results Two hundred patients (n = 100 in each group) were included. In group A, median selected tube current was 643 mAs (group B, 300 mAs; p < 0.001). Median values of CTDIvol, DLP and ED were 91.54 mGy, 1561 mGy cm and 2.97 mSv in group A, and 43.15 mGy, 769 mGy cm and 1.46 mSv in group B (p < 0.001). Image quality did not significantly differ between groups (p > 0.05). Conclusions ATCM yielded disproportionally high radiation dose due to substantial tube current increase at the frame level, while image quality did not improve. Thus, ATCM should preferentially be disabled.
关键词： Neuronavigation,Brain,Computed tomography angiography,Radiation dosage
更新于2025-09-23 15:22:29
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Accuracy of Calcium Scoring calculated from contrast-enhanced Coronary Computed Tomography Angiography using a dual-layer spectral CT: A comparison of Calcium Scoring from real and virtual non-contrast data
摘要： Modern non-invasive evaluation of Coronary Artery Disease (CAD) requires non-contrast low dose Computed Tomography (CT) imaging for determination of Calcium Scoring (CACS) and contrast-enhanced imaging for evaluation of vascular stenosis. Several methods for calculation of CACS from contrast-enhanced images have been proposed before. The main principle for that is generation of virtual non-contrast images by iodine subtraction from a contrast-enhanced spectral CT dataset. However, those techniques have some limitations: Dual-Source CT imaging can lead to increased radiation exposure, and switching of the tube voltage (rapid kVp switching) can be associated with slower rotation speed of the gantry and is thus prone to motion artefacts that are especially critical in cardiac imaging. Both techniques cannot simultaneously acquire spectral data. A novel technique to overcome these difficulties is spectral imaging with a dual-layer detector. After absorption of the lower energetic photons in the first layer, the second layer detects a hardened spectrum of the emitted radiation resulting in registration of two different energy spectra at the same time. The objective of the present investigation was to evaluate the accuracy of virtual non-contrast CACS computed from spectral data in comparison to standard non-contrast imaging.
关键词： virtual non-contrast data,Coronary Computed Tomography Angiography,Calcium Scoring,dual-layer spectral CT
更新于2025-09-04 15:30:14