Purpose: Stereotactic Radiosurgery (SRS) is an effective way of controlling the brain metastasis (BM) of lung carcinoma. This study evaluates the performance of dynamic contrast-enhanced MRI (DCE-MRI) and dynamic susceptibility contrast MRI (DSC-MRI) parameters to distinguish responders from non-responders at midterm follow-up in lung carcinoma BMs. Methods: Twenty-six patients (mean age 62 ± 10 years) with 54 lung carcinoma BMs (NSCLC 67%, SCLC 33%) underwent SRS. The DCE-MRI and DSC-MRI were performed at baseline and repeated 4–8 weeks post-SRS to predict treatment responses at the midterm follow-up (6–12 months). Midterm outcomes were classified according to RANO-BM criteria as responders (complete response, partial response, or stable disease) or non-responders (progressive disease). Receiver operating characteristic (ROC) analyses evaluated the diagnostic accuracy of individual perfusion parameters and their combinations. Results: Forty lesions (74%) were responders, while 14 (26%) were non-responders. Progressive lesions showed a mean volume increase of 5.5-fold, whereas responders demonstrated a 60% mean volume reduction. Responders showed significantly lower absolute post-SRS K-trans (median 0.015 vs. 0.035 min⁻¹; p = 0.005), a higher proportional decrease in K-trans from baseline (− 27% vs. +13%; p = 0.017), and lower post-SRS Ve (p = 0.009) compared to non-responders. Absolute post-SRS K-trans had the highest individual predictive accuracy (AUC = 0.75, accuracy = 78%, sensitivity = 86%, specificity = 55%). Neither the dynamic change nor post-SRS nCBV alone predicted midterm response; however, combining post-SRS nCBV with K-trans slightly improved predictive performance (AUC = 0.76, accuracy = 79%). Conclusion: Early post-SRS absolute K-trans is the best perfusion parameter for predicting midterm response in lung carcinoma BMs. DSC-MRI parameters alone offer limited predictive value.

Background/Objectives: Post-polio syndrome (PPS) affects former polio patients, manifesting decades after initial infection with progressive symptoms like pain, fatigue, and muscle weakness. Diagnosis relies on the clinical criteria and exclusion of other probable causes. The purpose of this study is to determine the scope and new diagnostic value of magnetic resonance imaging (MRI) in identifying muscle involvement in PPS and distinguishing it from prior poliomyelitis (PPM). Methods: This study was approved by the Koç University Ethics Committee with Approval No. 2023.409.IRB2.090. Electronic medical archives from two academic institutions were searched for records tagged with ICD code B-91 for poliomyelitis sequalae. The resulting search query of 291 records was manually sorted for PPS and PPM, medical history, clinical examination findings, and lumbar MR images down to 32 patients. Two independent radiologists evaluated the paraspinal musculature in the MRIs using the Mercuri scale. Inter-rater agreement, comparison of the paraspinal musculatures between groups, and their relationship to leg involvement were assessed with the resulting data. Results: Inter-rater agreement was found to be almost perfect across all muscles, except for the multifidus muscle. When clinical examination findings were included for these muscles, quadratus lumborum (QL) degradation was found in both right-side (p = 0.017) and left-side (p = 0.002) leg involvement. Conclusions: QL muscle deterioration may serve as a diagnostic marker for PPS, potentially guiding lumbar pain treatment through rehabilitation.

Purpose: The central vein sign (CVS) is a promising imaging biomarker for multiple sclerosis (MS) diagnosis. While isotropic T2* at 3 T and 7 T has demonstrated high diagnostic performance, its utility at 1.5 T remains unclear. This study evaluates the performance of unenhanced FLAIR-T2* fusion at 1.5 T compared to 3 T in MS participants. Methods: This prospective observational study included 20 MS patients and 20 control subjects. Each participant underwent unenhanced isotropic Epi-T2* and isotropic FLAIR (0.8 mm voxel size) at both 1.5 T and 3 T. Subsequently, the derived isotropic T2* and FLAIR were combined to create the final FLAIR-T2* fusion in both magnetic field strengths. Two independent raters assessed the CVS status of white matter (WM) lesions using NAIMS criteria. WM lesions were classified as CVS+ or CVS-, and two methods—select-n* and CVS+ proportion—were applied. Sensitivity and specificity were computed, and CVS performance was compared across WM lesion locations. Results: Among eligible WM lesions (MS: 258; controls: 255), the mean CVS+ lesion proportion per participant was 66.9 ± 15.4% for 1.5 T FLAIR-T2* and 77.0 ± 13.6% for 3 T FLAIR-T2* ( p < 0.01). At a 40% threshold, 1.5 T FLAIR-T2* achieved 90% sensitivity and 95% specificity, while 3 T FLAIR-T2* achieved 100% sensitivity and 95% specificity. The Select-6* method resulted in only one MS patient being misclassified at both field strengths. 3 T FLAIR-T2* detected more CVS+ lesions in deep WM (87.5% vs. 57.1%, p = 0.05). Conclusion: 1.5 T FLAIR-T2* fusion demonstrates high performance in CVS assessment, although slightly outperformed by 3 T FLAIR-T2*. The select-6* method may enhance 1.5 T performance, supporting its feasibility for CVS evaluation.