Fleury S.A. (Brazil)

To develop and validate a deep learning model for the detection of aberrant anterior tibial artery (AATA) on axial T2-weighted knee MRI, given the surgical relevance of unrecognized AATA and the lack of automated detection tools. This retrospective study included 70,260 MRI images from 2315 examinations (1441 without AATA and 874 with AATA) collected after institutional review board approval. Musculoskeletal radiologists performed image-level annotations. Data were split at the patient level into training, validation, and internal test sets; an independent dataset from another institution served as an external test set. A convolutional neural network was implemented in Python and PyTorch. Model performance was assessed at the patient level. At the slice level, the model achieved an F1-score of 0.838 on the internal test set. Patient-level classification using the validation-derived threshold (0.17) yielded F1-scores of 0.966 on the validation set, 0.979 on the internal test set, and 0.786 on the external test set. The area under the receiver operating characteristic curve for the external cohort was 0.97, indicating strong generalization despite a decrease in precision due to false positives. To our knowledge, this is the first study to apply artificial intelligence for automated detection of AATA on knee MRI. The proposed deep learning model performs this task with high sensitivity. Despite reduced precision in the external cohort, it demonstrates strong potential for enhancing preoperative risk assessment and surgical planning. Broader multicenter validation is warranted before clinical deployment.

Reference values for cardiac chamber quantification are essential for clinical decision-making. Brazil is a continental country with marked racial diversity and substantial regional socioeconomic and anthropometric variability, which may not be adequately represented in international echocardiographic standards. To establish reference echocardiographic measurements for healthy Brazilian adults and to investigate geographic and sex-related differences across Brazil's major regions. In this prospective, multicenter study, transthoracic echocardiograms were performed in 496 healthy volunteers (mean age 41 ± 15 years; 55% women) from five Brazilian regions. Left ventricular (LV) and left atrial (LA) dimensions, volumes, mass, ejection fraction, and global longitudinal strain (GLS) were analyzed in accordance with current guidelines. Comparisons were conducted by sex (Student's t test or Mann-Whitney U test) and by region (analysis of variance). Cardiac chamber dimensions and LV mass were greater in men, even after indexing for body surface area. LA volumes were also higher in men, although these differences were attenuated after indexing. Absolute LVGLS and right ventricle (RV) GLS (RVGLS) values were higher in women, whereas LA strain reservoir (LASr) was similar between sexes. Regionally, the Center-West exhibited significantly smaller LV volumes, a difference primarily driven by women, along with lower LVGLS and RVGLS (p < 0.001). In contrast, LA volumes were smaller in the Northeast region. No significant associations were observed between self-reported race and echocardiographic parameters, except for RVGLS and LASr, which were lower in White participants. This study establishes echocardiographic reference values in a nationally representative Brazilian cohort, confirms expected sex-related differences, and identifies previously unrecognized regional variations in cardiac chamber dimensions. These findings underscore the need for population-specific standards to ensure accurate cardiac quantification.

Anterior cruciate ligament reconstruction (ACLR) requires optimal graft healing for successful outcomes. Magnetic resonance imaging (MRI) is widely used to monitor graft maturation, with lower graft signal intensity suggesting better tissue organization and advanced healing. Hyperbaric oxygen therapy (HBOT) has shown promise in enhancing healing, but its effect on anterior cruciate ligament graft maturation in humans remains unclear. To evaluate the impact of adjuvant HBOT on graft maturation and integration in patients undergoing ACLR, using 4-month postoperative MRI. Cohort study; Level of evidence, 3. All patients who underwent primary anatomic ACLR with hamstring autografts and adjuvant HBOT were identified and matched 1:1 by sex and age (<25, 25-39, 40-54, and >55 years) with controls who did not receive HBOT. MRI was performed at 4 months postoperatively. Graft signal-to-noise quotient (SNQ) was measured to quantify graft maturation and analyzed using the Mann-Whitney U test; bone marrow edema at the graft-bone tunnel interface (graded as absent, mild, or accentuated) was used to infer graft integration and analyzed using the Fisher exact test. In total, 52 patients (26 HBOT, 26 controls; mean age 37.0 ± 13.5 years; 61.5% male) were included. Patients receiving HBOT exhibited significantly lower graft SNQ compared to controls (median difference, 83.9; P = .031), indicating improved graft maturation. Bone marrow edema at the graft-bone tunnel interface was also lower in the HBOT group (P = .029), suggesting enhanced graft integration. In this pilot study, adjuvant HBOT following ACLR was associated with significantly improved signs of graft maturation and integration, as evidenced by lower graft signal intensity and interface signal on MRI at 4 months, suggesting accelerated early healing. These findings may help refine strategies to enhance early graft incorporation and support the development of rehabilitation protocols that optimize postoperative outcomes for patients undergoing ACLR.

The periportal region is a complex anatomical area that includes important structures such as the hepatic artery, bile ducts, lymphatics, and nerves. Due to its rich architecture, diagnosing lesions in this space presents a significant challenge for radiologists. Various pathological conditions can affect this region, ranging from vascular and lymphatic diseases to infectious and malignant lesions. This article explores the main periportal conditions through various imaging methods, including ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and magnetic resonance cholangiopancreatography (MRCP). Therefore, understanding specific radiological manifestations is essential for differentiating clinical conditions and guiding appropriate treatment.

Background/Objectives: The relationship between thrombus imaging features and the natural evolution of stroke remains poorly defined. We aimed to investigate the associations between thrombus characteristics on CT and perfusion parameters, as well as subsequent infarct progression, in untreated patients experiencing an anterior circulation acute ischemic stroke (AIS). Methods: This retrospective analysis enrolled 81 untreated patients with AIS who underwent baseline non-contrast CT (NCCT), CT angiography (CTA), CT perfusion (CTP), and a follow-up NCCT. We evaluated the thrombus length, location, and clot burden score (CBS). CTP parameters included the ischemic core, hypoperfused tissue, and penumbra volumes. Infarct growth was the difference between the final infarct volume on a follow-up NCCT and the initial core volume on CTP. Univariate and multivariate regression models were performed. Results: Higher CBS values and shorter thrombi are associated with a reduced ischemic core (coefficients B of −3.9 and 0.88, p < 0.01), diminished hypoperfused tissue (coefficients B of −12.2 and 2.87, p < 0.001), and smaller penumbra volume (coefficients B of −7.9 and 1.99, p < 0.001). More distal occlusions were associated with smaller perfusion deficits. Importantly, a higher CBS and more distal thrombus location were significantly associated with a smaller final infarct volume and infarct growth volume. Conclusions: In untreated AIS patients, a lower thrombus burden (higher CBS, shorter length, distal location) is associated with more favorable baseline perfusion parameters and predicts a slower, less severe natural evolution of AIS. These findings underscore the prognostic value of baseline thrombus characteristics in determining the intrinsic course of a stroke.