Objectives: The aim of this study was to investigate the relationship between pathological classification of parotid gland tumors and conventional MRI – diffusion-weighted imaging findings and also contribute the possible effect of apparent diffusion coefficient (ADC) to diagnosis. Methods: 60 patients with parotid masses diagnosed using histopathology and/or cytology were enrolled in this retrospective study. All patients were evaluated using a 1.5 T MRI. Demographic features, conventional MRI findings, and ADC values (mean, minimum, maximum, and relative) were recorded. MRI findings and ADC values were compared between benign–malignant groups and pleomorphic adenoma vs Warthin’s tumor groups. Results: 60 tumors (48 benign, 12 malignant) were evaluated in a total of 60 patients (39 males, 21 females). The mean age was 59 (±14, 18–86) years old; the mean lesion size was 26 (±10, 11–61) mm. On the texture of conventional MRI, T2 dominantly hyperintense/with hypointensity signal was seen in 87% of pleomorphic adenomas and T2 dominantly hypointense/with hyperintesity signal was encountered in 64% of all Warthin’s tumors. Seven (28%) Warthin’s tumors were misdiagnosed as pleomorphic adenomas and two others (8%) as malignant tumors. The commonly used mean ADC value was 1.6 ± 0.6 × 10^–3 mm² s⁻¹ for benign tumors, 0.8 ± 0.3 × 10^–3 mm² s⁻¹ for malign tumors, 1 (0.9–1.8) × 10^–3 mm² s⁻¹ for Warthin’s tumors, and 1.9 ± 0.3 × 10^–3 mm² s⁻¹ for pleomorphic adenomas. There was a statistically significant difference in ADC values between benign-malignant tumors and pleomorphic adenomas-Warthin’s tumors. Conclusions: Warthin’s tumor may occasionally be misdiagnosed as pleomorphic adenoma and malignant tumor because of variable morphologic features. In addition to benign–malignant differentiation, the added ADC measurement may also be useful for differentiating Warthin’s tumors from pleomorphic adenomas.

Dir Journal Diagnostic and Interventional Radiology

Objective: The diagnostic success of apparent diffusion coefficient (ADC) histogram analysis in focal liver lesions, and the effects of quantitative data added to contrast-enhanced abdominal magnetic resonance imaging (MRI) on the diagnostic accuracy were investigated. Materials and Methods: The conventional MRI findings of 524 lesions in total were retrospectively examined. Contrast enhancement kinetics and ADC values for each lesion were found through an image analysis software. Results: Three hundred and fifty (67%) of the lesions were diagnosed as benign and 174 (33%) as malignant. Statistically significant difference was found between the benign and malignant lesion groups in terms of the minimum, maximum and mean ADC values (p<0.001). When optimal thresholds for minimum, maximum and mean ADC were taken as 1.47x10-3mm2/s; 1.85x10-3mm2/s; 1.72x10-3mm2/s respectively, sensitivity was found to be 97%; 83%; 95%, specificity was 100%; 98%; 99%, NPV was 100%; 99%; 99%, and PPV was 93%; 74%; 90%. ADC values added to MRI increased the diagnostic success for metastases (92%→96%), HCC (63%→73%), hemangioma (90%→99%) and FNH (56%→75%). Conclusion: ADC measurement could not show reasonable success in the diagnosis of specific lesions while being successful in the differentiation of benign and malignant lesions. Minimum ADC is more successful than mean and maximum ADC. A non-contrastenhanced MRI protocol based on the ADC measurement applicable to the selected patient group may be helpful.

Purpose: This study aimed to evaluate the diagnostic performance of GPT-4 Omni (GPT-4o) in emergency abdominal computed tomography (CT) cases compared to radiology residents with varying levels of experience, under conditions that closely mimic real clinical scenarios. Material and Methods: A total of 45 emergency cases were categorized into three levels of difficulty (easy, moderate, and difficult) and evaluated by six radiology residents with varying levels of experience (limited: R1–R2; intermediate: R3–R4; advanced: R5–R6) and GPT-4o. Cases were presented sequentially to both groups with consistent clinical data and CT images. Each case included 4 to 7 CT slice images, resulting in a total of 243 images. The participants were asked to provide the single most likely diagnosis for each case. GPT-4o’s CT image interpretation performance without clinical data and hallucination rate were evaluated. Results: Overall diagnostic accuracy rates were 76% for R1–R2, 89% for R3, 82% for R4–R5, 84% for R6, and 82% for GPT-4o. Case difficulty significantly affected the diagnostic accuracy for both the residents and GPT-4o, with accuracy decreasing as case complexity increased (p < 0.001). No statistically significant differences in diagnostic accuracy were found between GPT-4o and the residents, regardless of the experience level or case difficulty (p > 0.05). GPT-4o demonstrated a hallucination rate of 75%. Conclusions: GPT-4o demonstrated a diagnostic accuracy comparable to that of radiology residents in emergency abdominal CT cases. However, its dependence on structured prompts and high hallucination rate indicates the need for further optimization before clinical integration.

Correlation of 3T Diffusion-weighted MRI and 18F-FDG-PET/CT in Liver Metastases: SUV Versus ADC - Molecular Imaging and Radionuclide Therapy

Late post-pancreaticoduodenectomy hemorrhage (PPH) is a rare but potentially fatal complication associated with high morbidity and mortality. Early recognition and prompt intervention are critical for improving patient outcomes. This study aimed to evaluate the clinical features, treatment modalities, and outcomes of late-onset PPH cases managed in our institution. Between January 2016 and January 2025, a total of 220 patients underwent pancreaticoduodenectomy (PD) at the Department of General Surgery, XXX University Faculty of Medicine. Patients who developed late arterial hemorrhage, defined by the International Study Group of Pancreatic Surgery (ISGPS) as occurring more than 24 h after the index operation, were included. Demographic data, histopathological diagnoses, timing and source of bleeding, radiological and angiographic findings, treatment modalities, rebleeding events, morbidity, and mortality rates were analyzed. In patients undergoing endovascular treatment (EVT), technical success and complications were recorded. Late PPH occurred in 5.9% (13/220) of patients, with a mean onset of 10.3 days postoperatively. The most frequent bleeding source was the gastroduodenal artery (61.5%), and 61.5% of patients had an anastomotic leak. Sentinel bleeding was present in 76.9% of cases. EVT was performed in eight patients, achieving technical success in 75% after the first attempt and 100% after repeat procedures; rebleeding occurred in 25%. Surgical intervention was performed in five patients, with remnant pancreatectomy required in 60% of cases. Mortality was 60% in the surgical group and 25% in the EVT group. No cases of hepatic ischemia or abscess were observed following hepatic artery embolization. Endovascular therapy appears to be a feasible first-line approach for the management of late PPH and may achieve high technical success. Surgical intervention should be reserved for selected cases in which EVT is unavailable or unsuccessful.