Multiparametric MRI with MR elastography findings in patients with sinusoidal obstruction syndrome after oxaliplatin-based chemotherapy.

OBJECTIVE: To evaluate the magnetic resonance elastography (MRE)-derived liver stiffness measurement (LSM), T1 and T2 relaxation times, and hepatobiliary phase images in patients, who developed sinusoidal obstruction syndrome (SOS) after oxaliplatin-based chemotherapy. METHODS: Thirty-four patients (M/F:22/12) who underwent liver MRI-MRE and received oxaliplatin for colorectal, gastric, and pancreas cancer were included in the study. SOS was diagnosed by Gd-EOB-DTPA-enhanced MRI in 18 patients. MRE-LSM and T1-T2 maps were evaluated. Patients with SOS were grouped according to the amount of reticular hypointensity on the hepatobiliary phase images. RESULTS: The mean MRE-LSM in the patients with SOS was 3.14 ± 0.45 kPa, and the control group was 2.6 ± 0.5 kPa (p = 0.01). The mean-corrected T1 (cT1) relaxation time was 1181 ± 151 ms in the SOS group and 1032 ± 129 ms in the control group (p = 0.005). The mean T2 relaxation time was 50.29 ± 3.6 ms in the SOS group and 44 ± 3.9 ms in the control group (p = 0.01). Parenchymal stiffness values were 2.8 ± 0.22 kPa, 3 ± 0.33 kPa, and 3.65 ± 0.28 kPa in patients with mild, moderate, and advanced SOS findings, respectively (p = 0.002). Although cT1 and T2 relaxation times increased with increasing SOS severity, no statistical significance was found. CONCLUSIONS: We observed increased MRE-LSM in patients with SOS after chemotherapy compared to control group. T1 and T2 relaxation times were also useful in diagnosing SOS but were found inadequate in determining SOS severity. MRE is effective in diagnosing SOS and determining SOS severity in patients who cannot receive contrast agents, and it may be useful in the follow-up evaluation of these patients.

Aneurysm of the Communicating Vein Between the Left Renal Vein and Left Ascending Lumbar Vein Mimicking Retroperitoneal Lymphadenopathy: A Case Report.

INTRODUCTION: Aneurysm of the communicating vein between the left renal vein and left ascending lumbar vein is extremely rare, with only anecdotal reported cases. Unless detected and recognized promptly, this rare condition may give rise to severe bleeding in patients undergoing retroperitoneal surgery. It may also closely mimic enlarged retroperitoneal lymph nodes, paragangliomas, adrenal masses, or renal artery aneurysms. CASE REPORT: In this case study, we reported the imaging findings of this rare entity, which was falsely diagnosed as an enlarged retroperitoneal lymph node in an outside medical center, reported to be consistent with metastatic disease in a patient with newly diagnosed testicular cancer. CONCLUSION: The aneurysm of the communicating vein should be considered in the differential diagnosis in patients with testicular cancer and other disease processes where lymph nodes are commonly affected.

Prostatitis, the Great Mimicker of Prostate Cancer: Can We Differentiate Them Quantitatively With Multiparametric MRI?

OBJECTIVE. The purpose of this study was to investigate the diagnostic performance of semiquantitative and quantitative pharmacokinetic parameters and quantitative apparent diffusion coefficient (ADC) values obtained from prostate multiparametric MRI (mpMRI) to differentiate prostate cancer (PCa) and prostatitis objectively. MATERIALS AND METHODS. We conducted a retrospective review of patients with biopsy-proven PCa or prostatitis who underwent mpMRI study between January 2015 and February 2018. Mean ADC, forward volume transfer constant (Ktrans), reverse volume transfer constant (kep), plasma volume fraction (Vp), extravascular extracellular space volume fraction (Ve), and time to peak (TTP) values were calculated for both lesions and contralateral normal prostate tissue. Signal intensity-time curves were analyzed. Lesion-to-normal prostate tissue ratios of pharmacokinetic parameters were also calculated. The diagnostic accuracy and cutoff points of all parameters were analyzed to differentiate PCa from prostatitis. RESULTS. A total of 138 patients (94 with PCa and 44 with prostatitis) were included in the study. Statistically, ADC, quantitative pharmacokinetic parameters (Ktrans, kep, Ve, and Vp), their lesion-to-normal prostate tissue ratios, and TTP values successfully differentiated PCa and prostatitis. Surprisingly, we found that Ve values were significantly higher in prostatitis lesions. The combination of these parameters had 92.7% overall diagnostic accuracy. ADC, kep, and TTP made up the most successful combination for differential diagnosis. Analysis of the signal intensity-time curves showed mostly type 2 and type 3 enhancement curve patterns for patients with PCa. Type 3 curves were not seen in any prostatitis cases. CONCLUSION. Quantitative analysis of mpMRI differentiates PCa from prostatitis with high sensitivity and specificity, appears to have significant potential, and may improve diagnostic accuracy. In addition, evaluating these parameters does not cause any extra burden to the patients.

PET and PET-CT imaging findings of peritoneal and omental involvement in patients with lymphoma.

A retrospective institutional-review-board-approved study was performed evaluating positron emission tomography (PET)-computed tomography (CT) imaging findings of peritoneal and omental involvement of lymphoma. Twelve patients were identified with a wide spectrum of imaging findings on PET-CT including but not limited to peritoneal thickening, ascites, and serosal involvement. Lymphoma is among the rare causes of malignant peritoneal or omental involvement. The most common manifestations of peritoneal lymphomatosis are peritoneal 2-[fluorine 18] fluoro-2-deoxy-D-glucose uptake with corresponding peritoneal thickening and nonobstructive serosal masses on CT.