Ischemic Conditions of Lower Extremity Muscle - Alternative Method of Estimation Using Spectral Computed Tomography.
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ABSTRACT:
SUBMITTER: Matsukura M
PROVIDER: S-EPMC7897697 | biostudies-literature | 2019 Dec
REPOSITORIES: biostudies-literature
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Ischemic Conditions of Lower Extremity Muscle - Alternative Method of Estimation Using Spectral Computed Tomography.
Matsukura Mitsuru M Mochizuki Junji J Misawa Shinya S Hata Yoshiki Y
Circulation reports 20191203 12
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Project description:ObjectivesTo explore the association between lower extremity muscle features from CTA and peripheral arterial disease (PAD) severity using digital subtraction angiography (DSA) as reference standard.MethodsInformed consent was waived for this Institutional Review Board approved retrospective study. PAD patients were recruited from July 2016 to September 2020. Two radiologists evaluated PAD severity on DSA and CTA using runoff score. The patients were divided into two groups: mild PAD (DSA score ≤ 7) vs. severe PAD (DSA score > 7). After segmenting lower extremity muscles from CTA, 95 features were extracted for univariable analysis, logistic regression model (LRM) analysis, and sub-dataset analysis (PAD prediction based on only part of the images). AUC of CTA score and LRMs for PAD prediction were calculated. Features were analyzed using Student's t test and chi-squared test. p < 0.05 was considered statistically significant.ResultsA total of 56 patients (69 ± 11 years; 38 men) with 56 lower legs were enrolled in this study. The lower leg muscles of mild PAD group (36 patients) showed higher CT values (44.6 vs. 39.5, p < 0.001) with smaller dispersion (35.6 vs. 41.0, p < 0.001) than the severe group (20 patients). The AUC of CTA score, LRM-I (constructed with muscle features), and LRM-II (constructed with muscle features and CTA score) for PAD severity prediction were 0.81, 0.84, and 0.89, respectively. The highest predictive performance was observed in the image subset of the middle and inferior segments of lower extremity (LRM-I, 0.83; LRM-II, 0.90).ConclusionsLower extremity muscle features are associated with PAD severity and can be used for PAD prediction.Critical relevance statementQuantitative image features of lower extremity muscles are associated with the degree of lower leg arterial stenosis/occlusion and can be a beneficial supplement to the current imaging methods of vascular stenosis evaluation for the prediction of peripheral arterial disease severity.Key points• Compared with severe PAD, lower leg muscles of mild PAD showed higher CT values (39.5 vs. 44.6, p < 0.001). • Models developed with muscle CT features had AUC = 0.89 for predicting PAD. • PAD severity prediction can be realized through the middle and inferior segment of images (AUC = 0.90).
| S-EPMC10973322 | biostudies-literature
Project description:BACKGROUND:The sensitivity and specificity of exercise testing have never been studied simultaneously against an objective quantification of arterial stenosis. Aims were to define the sensitivity and specificity of several exercise tests to detect peripheral artery disease (PAD), and to assess whether or not defined criteria defined in patients suspected of having a PAD show a difference dependent on the resting ABI. METHODS:In this prospective study, consecutive patients with exertional limb pain referred to our vascular center were included. All patients had an ABI, a treadmill exercise-oximetry test, a second treadmill test (both 10% slope; 3.2km/h speed) with post-exercise pressures, and a computed-tomography-angiography (CTA). The receiver-operating-characteristic curve was used to define a cut-off point corresponding to the best area under the curve (AUC; [CI95%]) to detect arterial stenosis ≥50% as determined by the CTA. RESULTS:Sixty-three patients (61+/-11 years-old) were included. Similar AUCs from 0.72[0.63-0.79] to 0.83[0.75-0.89] were found for the different tests in the overall population. To detect arterial stenosis ≥50%, cut-off values of ABI, post-exercise ABI, post-exercise ABI decrease, post-exercise ankle pressure decrease, and distal delta from rest oxygen pressure (DROP) index were ≤0.91, ≤0.52, ≥43%, ≥20mmHg and ≤-15mmHg, respectively (p<0.01). In the subset of patients with an ABI >0.91, cut-off values of post-exercise ABI decrease (AUC = 0.67[0.53-0.78]), and DROP (AUC = 0.67[0.53-0.78]) were ≥18.5%, and ≤-15mmHg respectively (p<0.05). CONCLUSION:Resting ABI is as accurate as exercise testing in patients with exertional limb pain. Specific exercise testing cut-off values should be used in patients with normal ABI to diagnose PAD.
| S-EPMC6597112 | biostudies-literature
Project description:Lower extremity lymphedema (LEL) is a common complication after gynecological cancer treatment, which significantly reduces the quality of life. While early diagnosis and intervention can prevent severe complications, there is currently no consensus on the optimal screening strategy for postoperative LEL. In this study, we developed a computer-aided diagnosis (CAD) software for LEL screening in pelvic computed tomography (CT) images using deep learning. A total of 431 pelvic CT scans from 154 gynecological cancer patients were used for this study. We employed ResNet-18, ResNet-34, and ResNet-50 models as the convolutional neural network (CNN) architecture. The input image for the CNN model used a single CT image at the greater trochanter level. Fat-enhanced images were created and used as input to improve classification performance. Receiver operating characteristic analysis was used to evaluate our method. The ResNet-34 model with fat-enhanced images achieved the highest area under the curve of 0.967 and an accuracy of 92.9%. Our CAD software enables LEL diagnosis from a single CT image, demonstrating the feasibility of LEL screening only on CT images after gynecologic cancer treatment. To increase the usefulness of our CAD software, we plan to validate it using external datasets.
| S-EPMC10533488 | biostudies-literature
Project description:IntroductionImage quality reduction due to metallic artefacts is a significant challenge during vascular computed tomography (CT) imaging of the lower extremities in patients with hip prostheses. This study aims to analyse various reconstruction algorithms' ability to reduce metal artefacts due to two types of hip prostheses during lower extremity CT angiography examinations.MethodsA pelvis phantom was fabricated with the insertion of a tube filled with contrast media to simulate the femoral artery, and the phantom was then CT scanned with and without hip prostheses. Multimodal images were acquired using different kilovoltage peak (kVp) settings and reconstructed with different algorithms, such as filtered back projection (FBP), iterative reconstruction (iDose4), iterative model-based reconstruction (IMR) and orthopaedic metal artefact reduction (O-MAR). Image quality was assessed based on image noise, signal-to-noise ratio (SNR) and Hounsfield unit (HU) deviation.ResultsThe IMR approach significantly improved image quality compared to iDose4 and FBP. For the vascular region, O-MAR improves SNR by 5 ± 1, 23 ± 5 and 42 ± 9 for FBP, iDose4 and IMR respectively, and improves HU precision towards the baseline values by 49% and 83% for FBP and IMR, respectively. The noise reduction was 71% and 89% for FBP and IMR, and 57% for iDose4. O-MAR greatly enhances SNR corrections among the most severe artefacts, with 29 ± 1 and 43 ± 4 for FBP and IMR, compared to iDose4 by 37 ± 7.ConclusionIMR combined with O-MAR could improve the CT angiography of the lower extremities of patients with a hip prosthesis.
| S-EPMC11569399 | biostudies-literature
Project description:BackgroundEarly rectal neoplasms can be treated endoscopically with good prognosis, yet usually present with unspecific or an absence of signs and symptoms and are detected largely by invasive endoscopy with less compliance to screening. The purpose of this cross-sectional study was to explore the diagnostic value of dual-layer spectral detector computed tomography (DSCT) imaging for early rectal neoplasm.MethodsPatients who underwent DSCT for evaluation of rectal lesion or routine examination between September 2022 to September 2023 at West China Hospital were prospectively included and identified as group A (control, n=76), group B (rectal advanced adenomas and ≤T1 rectal cancer, n=59), and group C (≥T2 staging rectal cancer, n=74). Lesion visualization was graded to assess image quality. Spectral quantitative measurement, such as Hounsfield unit (HU)40 keV, HU70 keV, iodine concentration (IC), effective atomic number (Zeff), and the slope of spectral curve (λ), was analyzed and compared. Receiver operating characteristic (ROC) curves were generated to evaluate the diagnostic efficacy of spectral parameters. A comparison of ROC curves was applied to test the significance of differences between the area under the curves (AUCs).ResultsCompared to poly-energetic images (PEIs), the multiple parameters from DSCT were of greater capability to recognize rectal lesions. There were significant differences in HU40 keV (208.01±43.60 vs. 255.53±45.16), HU70 keV (87.06±18.55 vs. 100.78±18.26), IC [1.91 (1.71, 2.28) vs. 2.58±0.49], Zeff [8.33 (8.25, 8.50) vs. 8.61±0.20], and λ [3.80 (3.41, 4.52) vs. 5.16±1.00] between the early neoplastic lesions in rectum and the advanced rectal cancer (P<0.001). Significant correlations were found between the DSCT parameters and tumor staging (P<0.001). Furthermore, the AUCs of IC, Zeff, λ, and HUPEI were all above 0.90 for early rectal neoplasm detection, with additional capability of discriminating early rectal neoplasm from advanced rectal cancer.ConclusionsDSCT improved tumor conspicuity and the detection of the early rectal neoplastic lesion, suggesting that it is a promising screening tool in clinical practice.
| S-EPMC11651995 | biostudies-literature
Project description:BackgroundAcute ischemic lesions are challenging to detect by conventional computed tomography (CT). Virtual monoenergetic images may improve detection rates by increased tissue contrast.PurposeTo compare the ability to detect ischemic lesions of virtual monoenergetic with conventional images in patients with acute stroke.Material and methodsWe included consecutive patients at our center that underwent brain CT in a spectral scanner for suspicion of acute stroke, onset <12 h, with or without (negative controls) a confirmed cortical ischemic lesion in the initial scan or a follow-up CT or magnetic resonance imaging. Attenuation was measured in predefined areas in ischemic gray (guided by follow-up exams), normal gray, and white matter in conventional images and retrieved in spectral diagrams for the same locations in monoenergetic series at 40-200 keV. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Visual assessment of diagnostic measures was performed by independent review by two neuroradiologists blinded to reconstruction details.ResultsIn total, 29 patients were included (January 2018 to July 2019). SNR was higher in virtual monoenergetic compared to conventional images, significantly at 60-150 keV. CNR between ischemic gray and normal white matter was higher in monoenergetic images at 40-70 keV compared to conventional images. Virtual monoenergetic images received higher scores in overall image quality. The sensitivity for diagnosing acute ischemia was 93% and 97%, respectively, for the reviewers, compared to 55% of the original report based on conventional images.ConclusionVirtual monoenergetic reconstructions of spectral CIs may improve image quality and diagnostic ability in stroke assessment.
| S-EPMC10588276 | biostudies-literature
Project description:INTRODUCTION:Anatomic stenosis evaluation on coronary CT angiography (CCTA) lacks specificity in indicating the functional significance of a stenosis. Recent developments in CT techniques (including dual-layer spectral detector CT [SDCT] and static stress CT perfusion [CTP]) and image analyses (including fractional flow reserve [FFR] derived from CCTA images [FFRCT] and deep learning analysis [DL]) are potential strategies to increase the specificity of CCTA by combining both anatomical and functional information in one investigation. The aim of the current study is to assess the diagnostic performance of (combinations of) SDCT, CTP, FFRCT and DL for the identification of functionally significant coronary artery stenosis. METHODS AND ANALYSIS:Seventy-five patients aged 18 years and older with stable angina and known coronary artery disease and scheduled to undergo clinically indicated invasive FFR will be enrolled. All subjects will undergo the following SDCT scans: coronary calcium scoring, static stress CTP, rest CCTA and if indicated (history of myocardial infarction) a delayed enhancement acquisition. Invasive FFR of ≤0.80, measured within 30 days after the SDCT scans, will be used as reference to indicate a functionally significant stenosis. The primary study endpoint is the diagnostic performance of SDCT (including CTP) for the identification of functionally significant coronary artery stenosis. Secondary study endpoint is the diagnostic performance of SDCT, CTP, FFRCT and DL separately and combined for the identification of functionally significant coronary artery stenosis. ETHICS AND DISSEMINATION:Ethical approval was obtained. All subjects will provide written informed consent. Study findings will be disseminated through peer-reviewed conference presentations and journal publications. TRIAL REGISTRATION NUMBER:NCT03139006; Pre-results.
| S-EPMC6429912 | biostudies-literature
Project description:ObjectivePreprocedural computed tomography angiography (CTA) assists in evaluating vascular morphology and disease distribution and in treatment planning for patients with lower extremity peripheral artery disease (PAD). The aim of the study was to determine the predictive value of radiographic findings on CTA and technical success of endovascular revascularization of occlusions in the superficial femoral artery-popliteal (SFA-pop) region.MethodsMedical records and available imaging studies were reviewed for patients undergoing endovascular intervention for PAD between January 2013 and December 2015 at a single academic institution. Radiologists reviewed preoperative CTA scans of patients with occlusions in the SFA-pop region. Radiographic criteria previously used to evaluate chronic occlusions in the coronary arteries were used. Technical success, defined as restoration of inline flow through the SFA-pop region with <30% stenosis at the end of the procedure, and intraoperative details were evaluated.ResultsFrom 2013 to 2015, there were 407 patients who underwent 540 endovascular procedures for PAD. Preprocedural CTA scans were performed in 217 patients (53.3%), and 84 occlusions in the SFA-pop region were diagnosed. Ten occlusions were excluded as no endovascular attempt to cross the lesion was made because of extensive disease or concomitant iliac intervention. Of the remaining 74 occlusions in the SFA-pop region, 59 were successfully treated (80%) and 15 were unsuccessfully crossed (20%). The indications for revascularization were claudication in 57% of patients and critical limb ischemia in the remaining patients. TransAtlantic Inter-Society Consensus A, B, and C occlusions were treated with 87% success, whereas D occlusions were treated with 68% success (P = .047). There were nine occlusions with 100% vessel calcification that was associated with technical failure (P = .014). Longer lengths of occlusion were also associated with technical failure (P = .042). Multiple occlusions (P = .55), negative remodeling (P = .69), vessel runoff (P = .56), and percentage of vessel calcification (P = .059) were not associated with failure. On multivariable analysis, 100% calcification remained the only significant predictor of technical failure (odds ratio, 9.0; 95% confidence interval, 1.8-45.8; P = .008).ConclusionsAnalysis of preoperative CTA shows 100% calcification as the best predictor of technical failure of endovascular revascularization of occlusions in the SFA-pop region. Further studies are needed to determine the cost-effectiveness of obtaining preoperative CTA for lower extremity PAD.
| S-EPMC5898443 | biostudies-literature
Project description: Not available
| S-EPMC11926433 | biostudies-literature
Project description:BackgroundComputed tomography angiography (CTA) is the recommended diagnostic and follow-up imaging modality for acute aortic dissection (AD). However, the high-contrast medium burden associated with repeated CT aortography follow-ups remains a significant concern. This prospective study aimed to assess whether an ultra-low contrast dose (75% cutoff) aortic CTA protocol on dual-layer spectral CT could achieve comparable image quality with the full dose protocol. We also investigated the image quality of the virtual noncontrast (VNC) images derived from the ultra-low dose protocol.MethodsThis study included 37 consecutive patients who were referred to aortic CTA from May 2022 to August 2022. The enrolled patients underwent full-dose contrast CTA and ultra-low dose (reduced to 25% of conventional) contrast CTA on dual-layer spectral CT in 1 day. Virtual monochromatic images (VMIs) were reconstructed with 40 and 70 keV. The VNC images were reconstructed for both protocols. Objective image quality evaluation, recorded as signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs), was compared between the groups using 1-way analysis of variance and post hoc analysis with Bonferroni correction. Subjective image quality was also compared between the groups. Finally, VNC images derived from the low-dose (VNClow) and full-dose (VNCfull) protocols were compared to the true noncontrast (TNC) images.ResultsNeither CNR nor SNR was lower for the 40-keV images reconstructed from the ultra-low dose group compared to the conventional images. Both were significantly higher than those of the 70-keV images. Regarding subjective image quality, vessel enhancement was not significantly different between the 40-keV VMI and full-dose images [ascending aorta (AAO): 4.37±0.46 vs. 4.57±0.48, P=0.096; brachiocephalic arteries: 4.34±0.45 vs. 4.51±0.49, P=0.152; abdominal aortic side branch: 4.42±0.48 vs. 4.51±0.49, P=0.480]. The VNClow images were similar to the TNC images but significantly different from the VNCfull images (P<0.001).ConclusionsUltra-low contrast aortic CTA with a 75%-reduced iodine dose using dual-layer spectral CT and the derived VNC achieved image quality comparable to that of conventional CTA and TNC images.
| S-EPMC10585532 | biostudies-literature