Evaluating the Efficacy and Utility of Preoperative Computed Tomography Angiography in Perforator Flap Surgeries: A Systematic Review and Meta-Analysis.

Purpose To develop and validate an end-to-end autonomous platform for the quantification and visualization of brain aneurysm and parent artery morphology at CT angiography (CTA). Materials and Methods: A total of 2980 CTA scans performed between 2004 and 2025 containing 2585 aneurysms from 2980 patients obtained from five international high-volume stroke centers were included. The model was trained using expert hand-annotated vascular segmentations spanning the cervical internal carotid and vertebral arteries through the A4, M3, and P3 segments. Internal prospective and multicenter external testing assessed aneurysm detection performance and compared morphology measurements with expert-derived values obtained with digital subtraction angiography-verified CTA. Statistical analysis used paired t tests or Wilcoxon signed rank tests, with sensitivity, specificity, and 95% CIs reported. A public web-based platform was developed to allow further validation. Results Internal and multicenter external testing yielded a patient-level sensitivity of 87.9% (290 of 330; 95% CI: 83.6, 91.3) and specificity of 86.6% (395 of 456; 95% CI: 83.3, 89.4). Physician-performed morphology extraction required 24.3 minutes ± 6.6 per scan, whereas the model completed the task autonomously in 90 seconds ± 12 (P < .001). At the aggregate level, no statistically significant differences were observed for aneurysm volume, neck diameter, parent artery diameter, flow angle, aspect ratio, size ratio, height-width ratio, undulating index, ellipticity index, or nonsphericity index. Dome height (mean difference, 0.1 ± 1.1; P = .03) and surface area (mean difference, -5.3 mm2 ± 29.5; P = .04) differed but had minimal effect sizes. Conclusion The developed autonomous system for rupture-related morphology metric acquisition substantially reduced physician workload. Keywords: Intracranial Aneurysm, CT Angiography, Artificial Intelligence, Morphology, Rupture Risk Supplemental material is available for this article. © RSNA, 2026 See also commentary by Maiter and Kular in this issue.

Cerebrovascular diseases are major causes of death and disability worldwide, highlighting the critical importance of early diagnosis and accurate acquisition of vascular information. However, conventional imaging techniques using direct subtraction computed tomography (CT) and dual energy CT have limitations, including invasiveness, radiation exposure, and artifacts caused by metal and bone. This study investigated the feasibility of cerebral artery segmentation in single-exposure CT angiography (CTA) using a projection-domain framework derived from patient-based CTA data. The proposed method employs the DeepLab V3+ model to segment brain vessels directly in the projection. A total of 103 patients were included in the dataset, and 61, 17, and 25 patients were allocated to the training, validation, and test sets, respectively. This approach eliminates the risk of double exposure and motion artifacts while preserving clinical information. Additionally, this approach minimizes beam-hardening artifacts from high-density materials and reduces the operator's workload. The cerebral artery images reconstructed using the proposed method were quantitatively compared to those of the labeled images, and the intersection over union, Dice similarity coefficient, bidirectional Hausdorff distance, bfscore, F1-score, and precision were measured to be approximately 0.89 [95% CI, 0.87-0.91], 0.90 [0.88-0.91], 219.12 pixels [201.54-236.70], 0.90 [0.89-0.92], 0.90 [0.89-0.92], and 0.89 [0.88-0.91], respectively. Performance metrics consistently demonstrated high agreement between reconstructed vessel maps and reference labels. In addition, the proposed method confirmed that reconstructing cerebral arteries and metallic implant components may yield clinically relevant vascular image information with limited information loss. These results support the feasibility of the proposed method for generating cerebral arterial 3D images in CTA systems and suggest potential utility for improved vascular visualization and image quality, pending further clinical validation.

Delayed cerebral ischemia (DCI) remains a major determinant of poor functional outcome following aneurysmal subarachnoid hemorrhage (aSAH) and a diagnostic challenge, despite various monitoring modalities being employed in clinical practice. With a standardized definition of DCI now widely accepted, the present study aimed to compare the diagnostic performance of established monitoring methods and to provide external validation for computed tomography (CT) perfusion time-to-maximum (TMAX) and objective pupillometry. Data were derived from a cohort of patients with aSAH enrolled between March 2023 and November 2024 who underwent multimodal monitoring for DCI. Diagnostic performance of CT perfusion mean transit time (MTT), TMAX, CT angiography (CTA), transcranial Doppler ultrasonography (TCD), and dynamic infrared pupillometry (NPi) and areas under the receiver operating characteristic curve (AUROC) were calculated for each modality with respect to DCI events occurring within 24hours. We included 59 patients in the study who underwent multimodal non-invasive testing, identifying 25 DCI events. CTP MTT and TMAX had the highest AUROC (0.84; 95% CI, 0.75-0.93; 0.79, 95% CI 0.69-0.89) of non-invasive modalities and MTT had the highest sensitivity (0.80). TCD showed low sensitivity (0.23) and CTA and TCD showed poor positive predictive values (0.37 and 0.17). Pupillometry yielded no true positives. CT perfusion MTT demonstrated the highest diagnostic accuracy among all modalities evaluated. Future studies in larger, homogeneous cohorts are warranted to explore potential synergistic effects and optimize multimodal diagnostic strategies incorporating MTT.

The aim of this study was to compare preoperative right ventricle-to-left ventricle (RV/LV) ratios by computed tomography angiography (CTA) and echocardiography and evaluate treatment outcomes of ultrasound-assisted catheter-directed thrombolysis (USAT) or mechanical thrombectomy (MT) in patients with intermediate-risk pulmonary embolism (PE). We retrospectively identified patients treated for intermediate-risk PE from 2018 to 2023 defined by systolic blood pressure (BP) >90 mmHg and right ventricle dysfunction defined by RV/LV ratio >0.9 via echocardiogram. RV/LV ratios were also evaluated on diagnostic CTA for comparison to echocardiogram values. Patients underwent USAT or MT based on thrombus location and contraindications to thrombolysis. Primary outcomes were intensive care unit (ICU) length of stay (LOS), hospital LOS, and 30-day and 1-year survival. Secondary outcomes included RV/LV change post-treatment on echocardiography, concomitant deep vein thrombosis (DVT), elevated cardiac biomarkers, blood transfusion, history of DVT/PE or malignancy, and imaging modality comparison in determination of RV/LV and RV/LV changes. Of 120 patients from a single center treated for intermediate-risk PE, 100 underwent USAT and 20 MT. There was no difference in ICU LOS (2.4 vs 2.6 days; P = .67) or hospital LOS (4.8 vs 5.7 days; P = .41) for USAT and MT, respectively. There was no difference in 30-day (98% vs 100%), or 1-year survival (96% vs 90%). MT patients had greater incidence of blood transfusion (25% vs 5%; P = .011). CTA overestimated RV/LV ratios preoperatively compared with echocardiography (1.4; SD, 0.4 vs 1.3; SD, 0.2; P = .027). Patients undergoing MT were more likely to have identified lower extremity DVT compared with patients undergoing USAT (90% vs 65%; P = .033). Other secondary outcomes showed no significant differences between treatment groups. Both USAT and MT provide excellent short-term and intermediate outcomes in patients with intermediate-risk PE, similar survival rates, similar post-treatment change in right heart dysfunction, and comparable ICU and hospital stays. MT is associated with higher transfusion rates, so caution should be exercised in patients felt to be at risk from further blood loss. These findings support individualized, anatomy- and risk-based selection of catheter-based therapy within a multidisciplinary PE response framework.

Reconstruction of hand soft tissue defects relies on accurate perforator localization, yet conventional planning with computed tomography angiography or handheld Doppler requires mental three-dimensional (3D) translation, and is associated with mapping errors or intraoperative adjustments. This article evaluates the use of an innovative patient-specific, surface-conforming 3D-printed guides that convert segmented preoperative magnetic resonance imaging (MRI) data into tangible templates to project dorsal metacarpal artery (DMA) perforator emergence points onto the skin with reproducible accuracy. In an illustrative case, a 66-year-old man underwent wide local excision of a digital porocarcinoma followed by propeller flap reconstruction. The third and fourth DMA perforators were identified from MRI, with a 2mm-thick dorsal hand shell designed with 1cm fenestrations corresponding to perforator emergence points. The perforators were marked onto the skin through the custom guide preoperatively, with skin markings cross verified with handheld Doppler. Reconstruction proceeded using a fourth DMA perforator-based propeller flap rotated to achieve tension-free coverage, with complete flap survival and restoration of full digital motion and satisfactory aesthetics. The 3D-printed guide reduced cognitive load, accelerated perforator localization, and minimized unnecessary dissection, supporting shorter tourniquet duration and safer elevation. The hand's distinct bony landmarks and stable contours enable reliable registration of rigid surface guides. As costs and workflows for imaging-to-print continue to decrease, patient-specific 3D-printed guides represent a practical, scalable adjunct that improved accuracy, efficiency, and reproducibility in perforator-based hand reconstruction.

Outcome of a Prospective Registry to Evaluate the Performance of the MANTA Vascular Closure Device in EVAR Patients.

Post-TIPS overt hepatic encephalopathy (OHE) and variceal rebleeding (VRB) remain serious complications with limited predictive tools. This study investigates whether the inherent preoperative three-dimensional portal venous geometry (3D-PVG) serves as an independent prognostic biomarker for 1year OHE and VRB in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS). In this multicenter retrospective study, 579 cirrhotic patients undergoing successful TIPS were enrolled. We extracted 3D-PVG features from routine computed tomography angiography (CTA) images before TIPS, quantifying bifurcation angles ('Near') and vessel segment tortuosity ('Far'). Cox regression identified predictors for 1-year OHE and VRB. Model performance was evaluated using Harrell's C-index, comparing clinical models against integrated clinical-geometric models (3D-CGM). For 1-year OHE, increased age (HR 1.458, p < 0.001), higher BUN (HR 1.171, p = 0.019), and extremely flat bifurcations (near_bin_87: 172°-174°; HR 1.104, p = 0.039) were independent risk factors. For 1-year VRB, first bleeding (HR 2.347, p = 0.027), elevated Cr (HR 1.244, p = 0.012), relatively flat bifurcations (near_bin_74: 146°-148°; HR 1.432, p = 0.001), and very straight vessel segments (far_bin_2: 2°-4°; HR 1.467, p = 0.013) were risk factors, while use of covered stents (HR 0.197, p = 0.013) and gently curved vessel segments (far_bin_27: 52°-54°; HR 0.262, p = 0.018) were protective factors. Integrating 3D-PVG features significantly improved predictive performance: the 3D-CGM achieved C-indices of 0.801 for OHE and 0.792 for VRB, surpassing clinical models (0.715 and 0.686, respectively). The inherent portal venous geometry may serve as an independent imaging biomarker for post-TIPS outcomes. The 3D-CGM markedly enhances risk prediction, providing a non-invasive approach for prognosis assessment in portal hypertension.

Longitudinal trajectory of thoracic CTA-derived sarcopenia stratifies mortality risk in transcatheter aortic valve replacement.

Vision-language model with siamese bilateral difference network and text-guided image feature enhancement for acute ischemic stroke outcome prediction on CT angiography

Haemoptysis, defined as the expectoration of blood from the lower respiratory tract, can present to the emergency department (ED) with symptoms ranging from mild, self-limiting to massive haemorrhage. Severe presentations account for approximately 5% of cases, with mortality primarily because airway flooding with blood leading to hypoxia. This underscores the importance of early airway protection and structured resuscitation in emergency settings. This narrative review summarizes the current evidence to guide emergency physicians in the management of haemoptysis. Aetiologies vary geographically: pulmonary tuberculosis accounts for up to 40% of cases in low- and middle-income countries, whereas malignancy, cardiovascular disease, and bronchiectasis predominate in high-income regions. Management begins with differentiating haemoptysis from pseudohaemoptysis and gastrointestinal bleeding, followed by risk stratification and initial stabilization of the patient. CT angiography helps in localization of bleeding and underlying pathology, while flexible bronchoscopy is the gold standard for both diagnosis and therapeutic interventions. Nebulized tranexamic acid is emerging as a rapid, localized, and safe adjunct in emergency settings, reducing the need for invasive procedures. Haemostasis can be achieved by bronchial artery embolization in over 90% of cases, while surgery is reserved for refractory or localized disease. Despite these advances, challenges remain in optimizing the timing and integration of imaging, pharmacological adjuncts, and invasive procedures. A multidisciplinary approach involving emergency physicians, pulmonologists, interventional radiologists, and thoracic surgeons is crucial to improving outcomes in this complex, potentially life-threatening condition. Further studies are needed to standardize protocols and priorities for emergency management of massive haemoptysis.

CT scans use iodinated contrast media (ICM) to increase enhancement of soft-tissue structures. Some techniques, such as CT angiography, accentuate specific anatomy. The chemical structure of ICM is rich in iodine. Because of iodine's high atomic number, use of ICM causes an increase in CT number and image contrast. Improper contrast enhancement is a leading motivator for both repeated CT examinations and those with limited or suboptimal diagnostic utility. Optimization of contrast agent administration is essential to avoid poor enhancement. Many interacting factors affect contrast enhancement and can be divided into three main categories: physics-based, patient-related, and contrast protocol-based factors. Physics-based factors include tube potential, beam hardening, and scan duration. Patient-related factors include blood volume and cardiac output. Contrast protocol-based factors include contrast agent volume, injection rate, iodine concentration, scan delay, and saline flush. These factors can be further stratified into scalar, temporal, and sampling factors. Scalar factors change the magnitude of enhancement by a fixed percentage independent of time (eg, changing tube potential or iodine concentration). Temporal factors modify the temporal dynamics of contrast enhancement (eg, changes in cardiac output or injection rate). Sampling factors affect how an ICM enhancement curve is sampled (eg, scan duration, scan delay). Understanding the available parameters and their impact on ICM enhancement equips the reader with tools to optimize contrast agent delivery and scanning protocols in CT. © The Author(s) 2026. Published by the Radiological Society of North America under a CC BY 4.0 license.

The inflammation-microvascular axis in prognosis: Integrated FAI and AMR assessment for risk stratification after PCI in NSTEMI patients.

Coronary artery disease (CAD) progression is directly associated with major adverse cardiovascular events and death. This study aimed to construct a pericoronary adipose tissue (PCAT) radiomics model to predict subsequent progression in patients with CAD. Data from 116 patients who had at least 2 coronary computed tomography angiography (CCTA) exams between March 1, 2020, and August 30, 2022, were collected at our institution. Obstructive stenosis, CAD-RADS classification, segment involvement score (SIS), and segment stenosis score (SSS) were noted. The radiomics features of the proximal to the left anterior descending artery, left circumflex artery, and right coronary artery were extracted on CCTA images using fully automated software. According to CAD-RADS, SIS, and SSS, non-progression was identified in 96, 80, and 72 patients and progression was identified in 20, 36, and 44 patients, respectively. All patients were randomly divided into the training and testing cohorts in a 7:3 ratio. Cox regression models were constructed based on PCAT radiomics signatures, and their predictive abilities were measured using receiver operating characteristic curves. We included 116 patients (age 58.00 [53.25, 64.00] years; 78 [67.20%] were male). After screening, 16 PCAT radiomics features were identified as being significantly related to CAD progression. The Cox regression models had area under the curve values of 0.841, 0.838, and 0.725 in the training cohort and 0.818, 0.817, and 0.851 in the testing cohort, respectively, to predict 2-year CAD-RADS, SIS, and SSS progression. PCAT-based radiomics models demonstrated promising performance in predicting subsequent CAD progression. PCAT-based radiomics signatures derived from coronary CT angiography provided incremental predictive value for CAD progression beyond conventional imaging markers (CAD-RADS, SIS, SSS), and may serve as noninvasive imaging biomarkers for individualized risk stratification.

Stress echocardiography (SE) detects myocardial ischemia while coronary computed tomography angiography (CCTA) detects structural abnormalities associated with coronary artery disease (CAD). A pilot retrospective study of 270 consecutive patients who underwent both SE and CCTA to explore which test is more accurate in patients with CAD. Health records and risk factors, SE, and CCTA outcomes were reviewed. SE outcomes were positive (n = 36) and negative (n = 234); CCTA outcomes were based on CAD severity (absent, mild, moderate, and severe). 219 (81.1%) patients had a positive CCTA, indicating the presence of CAD with mild, moderate, or severe stenosis. Despite a positive CCTA (n = 191), 70.7% had a negative SE. This discrepancy was most prevalent in the moderate CCTA category, where 110 patients had a negative SE but positive CCTA. Additionally, 9 patients demonstrated a positive SE despite no significant CCTA findings, indicating that functional abnormalities could have remained undetected by anatomical imaging. It is suggested that significant CAD detected by CCTA does not necessarily suggest myocardial ischemia, while the presence of myocardial ischemia is not necessarily associated with significant CAD, suggesting other causes (e.g., microvascular angina). A positive CCTA but negative SE findings may suggest the presence of coronary collaterals.

Iatrogenic pulmonary vein obstruction (PVO) is a rare but serious complication that may occur following transcatheter correction of sinus venosus atrial septal defect (SVASD) with partial anomalous pulmonary venous connection (PAPVC) using covered stents. This procedure has gained increasing acceptance in recent years. The optimal management strategy, particularly the role of conservative therapy, remains poorly defined. A 42-year-old man with a 1.5 × 1.0cm superior vena cava (SVC)-type SVASD, PAPVC, and severe pulmonary arterial hypertension (PAH) underwent transcatheter repair after six months of targeted vasodilator therapy. Under fluoroscopic and transesophageal echocardiographic (TEE) guidance, a 57mm long Optimus-CVS PTFE-covered XXL stent (AndraTec, Germany) was deployed, internally telescoped with a 45mm long bare-metal CP stent (NuMED, USA) for cranial anchoring. Intra-procedural TEE showed correct stent position and unobstructed pulmonary venous flow. However, 24h later, the patient developed acute hypoxemia. Computed tomography angiography revealed complete occlusion of the anterior segment of the right upper pulmonary vein with associated thrombosis. Because the patient remained hemodynamically stable, conservative management was initiated with corticosteroids, diuretics, and therapeutic anticoagulation (apixaban plus aspirin). Within five days, oxygen saturation normalized to 90% on room air, and chest imaging confirmed resolution of pulmonary infiltrates. Follow-up at six months showed a stable stent position and no residual obstruction. PVO following transcatheter SVASD repair may not be diagnosed immediately after stent deployment, as it can present with delayed onset due to progressive thrombosis formation. Normal intra-procedural imaging does not exclude subsequent PVO, and vigilant post-procedural monitoring is essential. In carefully selected, hemodynamically stable patients, conservative management with corticosteroids, anticoagulation, and diuretics can lead to complete clinical and radiographic recovery, restoring pulmonary venous drainage and potentially avoiding reintervention or surgery.

Cardiac Allograft Vasculopathy Assessment in Heart Transplanted Patients: The Value of Cardiac Computed Tomography Angiography

Comparative Diagnostic Performance of Cardiac Computed Tomography Angiography and Invasive Coronary Angiography for Coronary Artery Vasculopathy Surveillance After Heart Transplantation

Sex differences in acute chest pain care in a multisite U.S. emergency department cohort.

Electromagnetic Intraoperative Positioning System (IOPS) Is Safe and Effective as a 3D Imaging Adjunct in Endovascular Aortic Surgery-A Safety and Feasibility Study.