The first reported case of left renal vein fenestration.

PURPOSE: Vascular fenestrations are mostly seen in the arterial system and cerebral vessels, but they can be seen rarely in the venous system. In this article, we aimed to present the first case of left renal vein fenestration, which has not been previously reported in the English literature to the best our knowledge. METHODS: Computed tomography angiography (CTA) examination was performed on a 40-year-old male patient who presented with rectal bleeding, and iron deficiency anemia, detected hemorrhoids in colonoscopy, and was planned for superior rectal artery embolization. RESULTS: In CTA examination, a fenestration in the middle part of the left renal vein was detected. The fenestrated segment length was measured approximately 3 cm. The diameter of anterior and posterior channels were 7.66 and 6.01 mm, respectively. The 2.85 mm diameter inferior segmental artery of the left renal artery was passing between the anterior and posterior channels of the fenestrated segment, and there was a slight indentation of this artery to the posterior canal. CONCLUSION: Although venous fenestrations are rare, they can also be seen in the renal venous system, and can be detected with CTA. It is important for radiologists to be aware of this situation, to increase its detectability and to prevent iatrogenic injury in possible surgical procedures. And also as in our case, left renal vein fenestration may be one of the causes of microscopic hematuria.

Whole-lesion CT histogram analysis as an advanced technique in the portal venous phase: differentiating lipid poor adrenal adenomas from pheochromocytomas.

PURPOSE: Adrenal computed tomography (CT) has limitation due to imaging overlaps inthe washout characteristics of pheochromocytomas and adenomas (especially lipid-poor). The aim of this study was to investigate the distinguishability of lipid-poor adrenal adenomas and pheochromocytomas using whole-lesion CT histogram analysis. MATERIALS AND METHODS: Histopathologically proven 24 lipid-poor adenomas and 29 pheochromocytomas (total 53 lesions in 53 patients) were included in this retrospective study. Data obtained from standard and volumetric examinations of the lesions by dedicated adrenal CT were compared between the two groups using univariate analysis. Parameters that showed differences were further evaluated using multivariate logistic regression analysis. RESULTS: Univariate analysis revealed significant differences between the two groups in terms of lesion size, lesion volume, percentage of relative wash out, peak HU values and the percentage of voxels with attenuation ≥ 100 HU, ≥ 110 HU and ≥ 120 HU (p = 0.0001, P = 0.0001, P = 0.01, P = 0.008, p = 0.04, p = 0.02, p = 0.02, respectively). Multivariate analysis revealed lesion size ≥ 22.05 mm (OR: 22; p < 0.0001), the percentage of voxels with attenuation ≥ 120 HU being ≥ 9% (OR: 3.27; p = 0.04), peak HU value ≥ 161.5 HU (OR: 4.40; p = 0.01) as risk factors for pheochromocytomas. CONCLUSIONS: Whole lesion CT histogram analysis can be used to differentiate pheochromocytomas from lipid-poor adenomas. Lesion volume, the percentage of voxels with attenuation ≥ 120 HU and peak HU values are independent parameters that can assist in this differentiation. These findings may help avoid unnecessary biopsies and surgeries for lipid-poor adenomas, while identifying pheochromocytoma risk may improve perioperative patient management. Our results should be validated by future prospective studies.