Yunus Emre Senturk

Chronic migraine (CM) is associated with neurobiological alterations beyond episodic attacks, yet cerebral microvascular perfusion changes during the interictal phase of CM remain underexplored. Intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) provides diffusion‐derived pseudoperfusion parameters that reflect regional microvascular alterations in the brain parenchyma. Accordingly, this study aimed to investigate right‐to‐left hemispheric asymmetry of IVIM‐derived perfusion parameters in migraine‐implicated cortical and subcortical regions during the interictal phase of CM. Thirty patients with CM imaged during the interictal phase, along with 30 age‐ and sex‐matched healthy controls, underwent IVIM imaging. IVIM parameters, including the pseudodiffusion coefficient ( D* ), perfusion fraction ( f ), and their composite metric ( fD* ), were estimated using a Bayesian probability‐based fitting algorithm. Region‐of‐interest (ROI) analysis was performed bilaterally in migraine‐implicated cortical and subcortical regions. Hemispheric asymmetry indices (HAIs) of IVIM parameters were calculated and compared between groups using Benjamini–Hochberg (FDR) false discovery rate correction. No absolute IVIM parameter showed significant interhemispheric differences in either group after FDR correction. In addition, no significant group differences in HAI of IVIM parameters were identified across the six cortical regions or pontine tegmentum. In contrast, posterior thalamic fD* asymmetry was significantly greater in patients with CM than in controls (median HAI: 27.91 vs. 10.43; p = 0.002, q = 0.017). Exploratory analysis confirmed greater separation between bilateral posterior thalamic fD* measurements in CM versus control subjects (0.429 vs. 0.151 × 10 ⁻³ mm ² /s; p = 0.002), whereas leave‐one‐out analysis showed that this outcome was not driven by any single participant. Interobserver agreement for HAI measurements was good for D* (ICC = 0.81) and moderate for f and fD* (ICC = 0.70 and 0.69, respectively). These findings indicate that CM is associated with increased hemispheric asymmetry of IVIM‐derived microvascular perfusion in the posterior thalamus during interictal phase, suggesting lateralized thalamic microvascular alterations in CM.

Purpose Delayed remote epidural hematoma (EDH) is an exceptionally rare complication of non-traumatic neurosurgical procedures. Although venous bleeding related to abrupt intracranial pressure or volume redistribution has been proposed, the bleeding source is usually inferred rather than directly visualized. We report a delayed contralateral remote EDH after supratentorial tumor resection with direct radiographic evidence of a superficial cortical venous source and provide a review of the literature. Methods A comprehensive literature search was performed across PubMed/MEDLINE, Scopus, Web of Science, and the Cochrane Library without temporal restriction. Studies were eligible if they reported individual patient-level data on delayed postoperative epidural hematoma located remote from the operative field after a non-traumatic neurosurgical procedure. Reports of traumatic, intraoperative, immediate, operative-site, or contiguous epidural hematomas were excluded. Two reviewers (E.A.U., O.B.) independently screened records, assessed eligibility, and extracted demographic, clinical, radiological, management, and outcome data for descriptive synthesis. The illustrative case was analyzed with emphasis on clinical and radiographic findings, venous anatomy, and hematoma evolution. Results The structured review identified 14 previously reported patients with delayed remote postoperative EDH; with the present case, 15 patient-level observations were analyzed. Hydrocephalus was documented in 11 patients (73.3%), and CSF diversion or outflow alteration in 8 (53.3%). Altered mental status was the most common presentation at EDH recognition, occurring in 8 patients (53.3%). Surgical evacuation was performed in 14 patients (93.3%) and the present case was the only patient managed entirely without operative evacuation. Overall, 12 patients (80.0%) had favorable outcomes, 3 (20.0%) had residual neurological deficit or functional decline, and no deaths were reported. Conclusions Delayed remote EDH after large-volume supratentorial tumor resection may arise from a superficial cortical venous source. Postoperative sequential imaging in high-risk resections, with preoperative hydrocephalus, superficial venous anomaly, or CSF diversion, may identify remote EDH before neurological deterioration. In selected neurologically intact patients with stable or decreasing hematoma volume, conservative management under close neurosurgical surveillance may be a reasonable approach.

Objective: The objective of this study was to investigate the relationship between intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and dynamic contrast-enhanced MRI (DCE-MRI) parameters in soft tissue tumors (STTs). Methods: This retrospective study included patients with histopathologically confirmed STTs who underwent both DCE-MRI and IVIM-DWI between March 2022 and February 2024. Patients with prior therapy and lipomatous tumors were excluded. DCE-MRI parameters (K_trans, K_ep, V_e, iAUC) were obtained from pharmacokinetic maps using manually placed regions of interest (ROIs) in the most perfused tumor areas, avoiding necrotic and cystic regions. Corresponding ROIs were applied to IVIM-DWI maps. IVIM parameters (D, D*, f) were calculated using 11 b-values. Results: Twenty-nine patients (mean age, 56 ± 18 years; 14 malignant, 15 benign) were included. Interobserver agreement was excellent for DCE-MRI parameters, whereas IVIM-DWI parameters showed moderate-to-good agreement, with D showing the lowest reproducibility. In malignant tumors, f demonstrated strong positive correlations with K_trans (r = 0.81, p < 0.001) and iAUC (r = 0.79, p < 0.001), both of which remained significant after correction for multiple comparisons. fD* was higher in malignant than in benign lesions in the unadjusted group comparison; however, diagnostic performance was not evaluated in the present study. No significant differences were observed for DCE-MRI parameters between benign and malignant tumors. Conclusions: IVIM-DWI parameters demonstrated associations with DCE-MRI metrics in malignant STTs and may provide complementary information regarding tumor perfusion. However, the findings should be interpreted cautiously because ROI analysis was limited to a single representative slice. Further validation using larger cohorts and volumetric tumor assessment is required.

Differentiating Progressive Supranuclear Palsy from Idiopathic Normal Pressure Hydrocephalus: A Comparative Study of MR Parkinsonism Indices and Midbrain Qualitative Features - Medical Journal of Bakirkoy

Stent-assisted coiling (SAC) is a well-defined and widely performed endovascular technique used to treat wide-neck aneurysms. The Low-Profile Visualized Intraluminal Support (LVIS) EVO stent is a newly-developed, low-profile, braided stent with a composite wire structure providing full stent visibility under fluoroscopy. Although the initial and midterm results of patients with intracranial aneurysms treated with LVIS EVO-assisted coiling have been reported, no published long-term aneurysm occlusion or complication data exist for the LVIS EVO stent. This retrospective study aimed to evaluate the long-term safety and durability of the SAC procedure using an LVIS EVO stent for the treatment of wide-neck and complex aneurysms. A retrospective review of databases of 4 centers was performed to identify the patients with aneurysms treated with LVIS EVO-assisted coiling. Patients with a clinical and angiographic follow-up duration of at least 12 months were included. The technical success of the procedure and the immediate clinical and angiographic outcomes were assessed. Periprocedural and delayed complications were evaluated. Follow-up angiographic and clinical outcomes were investigated. Preprocedural and follow-up neurologic statuses were assessed using the mRS. The aneurysm occlusion status was assessed using the Raymond-Roy (RR) classification. A total of 158 patients (96 women; mean age, 54.4 [SD, 11.9] years) with 158 aneurysms were included. The technical success of the procedure was 99.4%. Immediate postprocedural angiography showed complete occlusion in 71.5% of patients. Every patient underwent at least 2 angiographic follow-ups. The last follow-up angiography evaluation showed a complete aneurysm occlusion (RRI) in 85.4% and an adequate occlusion (RRI-RRII) in 96.8% of patients. Recanalization was observed in 8.2% of the patients. Two patients (1.3%) required retreatment. In addition, 8.9% of patients had complications resulting in a morbidity rate of 4.4% (mRS scores, 1-3). At the last follow-up, 91.8% of the patients had an mRS score of ≤1. The results of this case series demonstrated the long-term safety and durability of the LVIS EVO-assisted coiling procedure for the treatment of wide-neck and complex aneurysms.

Objective: Tumor grade is critical for prognosis, metastatic risk, and treatment planning in soft tissue sarcomas (STSs). This study evaluated the role of quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters and diffusion-weighted imaging (DWI) in predicting STS grade. Methods: Between March 2022 and February 2023, patients with histopathologically confirmed STS who underwent DCE-MRI and DWI were retrospectively included; those with prior therapy or liposarcoma were excluded. Two musculoskeletal radiologists (3 and 4 years of experience) reviewed the exams. Age, gender, and tumor diameter (LD) were recorded. Dynamic contrast-enhanced magnetic resonance imaging measurements were obtained from Ktrans maps, avoiding hemorrhagic, necrotic, and cystic areas. Regions of interest were placed over the most perfused region (max) and a broader area (mean). Parameters (Ktrans, area under the curve [AUC], Kep, Ve) and enhancement curves were documented. Apparent diffusion coefficient (ADC)min and ADCmean were measured from ADC maps. Soft tissue sarcomas were grouped by pathological grade (1-3) and as low (1-2) vs. high (3). Results: Fourteen patients (3 females, 11 males) were included: 4 grade 1, 2 grade 2, and 8 grade 3. Mean age was 58.07 ± 16.35 years; mean LD 113.36 ± 36.87 mm. Inter-observer agreement was excellent for perfusion max values and ADCmin, and good for perfusion mean and ADCmean. No significant differences were found in age or LD. Apparent diffusion coefficient (ADC)mean (P = .026), ADCmin (P = .029), and AUCmax (P = .047) differed among grades. In low- vs. high-grade comparison, ADCmean, ADCmin, Ktransmax, AUCmax, and Ktransmean were significant. Conclusion: Apparent diffusion coefficient (ADC)min, ADCmean, AUCmax, Ktransmax, and Ktransmean may support STS grading. Cite this article as: Peker A, Çeliksöz AH, Özen Atalay H, Canturk EM, Şentürk YE. The role of quantitative DCE-MRI and diffusion-weighted imaging in differentiating the grade of soft tissue sarcomas. Cerrahpaşa Med J. 2026, 50, 0074, doi: 10.5152/ cjm.2026.25074.