Department of Radiology, University of California, Davis Medical Center, 4860 Y St, Ste 3100, Sacramento, CA 95817, USA.
AJR Am J Roentgenol. 2011 Oct;197(4):W674-9. doi: 10.2214/AJR.11.6463.
The objective of our study was to retrospectively determine whether segmental enhancement inversion or other CT patterns seen at enhanced biphasic MDCT are predictive for the diagnosis of renal oncocytoma.
Twenty-nine patients with 32 oncocytomas diagnosed by either biopsy or resection who had undergone enhanced biphasic CT between January 2004 and March 2010 were included in this study. Biphasic CT scans were analyzed for the presence of segmental enhancement inversion. Segmental enhancement inversion was defined as a renal mass with two distinctive segments in which the attenuation of the segments changed between the two phases of CT. The masses were further characterized on imaging to determine if any imaging feature is predictive of renal oncocytoma.
Of the 32 renal oncocytomas, 16 oncocytomas were eliminated from analysis. These masses were eliminated because they were larger than 4 cm (n = 4), the CT examinations were inadequate (n = 10), or the pathology results were questionable (n = 2). The remaining 16 tumors (mean size, 2.6 cm; range, 1.8-3.9 cm) were included in our study. Only two tumors showed distinct segments of variable degrees of enhancement, with one of those tumors having segmental enhancement inversion. Three masses had a central region of low density. The most common feature, identified in eight of the 16 oncocytomas, was a slightly heterogeneous mass that became homogeneous on the later phase of CT. Three oncocytomas had a homogeneous appearance on both phases.
Contrary to a prior report, we did not find segmental enhancement inversion to be a characteristic enhancement pattern of small renal oncocytomas on biphasic MDCT. We found no specific features on biphasic CT that could be considered reliable and could strongly suggest the diagnosis of renal oncocytoma.
本研究旨在回顾性确定增强双能 MDCT 所见的节段性增强反转或其他 CT 模式是否可预测肾嗜酸细胞瘤的诊断。
本研究纳入 2004 年 1 月至 2010 年 3 月期间接受增强双能 CT 检查且经活检或切除诊断为 32 例嗜酸细胞瘤的 29 例患者。分析双能 CT 扫描中是否存在节段性增强反转。节段性增强反转定义为具有两个不同节段的肾肿块，在 CT 的两个阶段之间，这些节段的衰减发生变化。对这些肿块进行进一步的影像学特征分析，以确定任何影像学特征是否可预测肾嗜酸细胞瘤。
32 个肾嗜酸细胞瘤中，有 16 个被排除在分析之外。这些肿块被排除是因为它们大于 4cm（n=4）、CT 检查不充分（n=10）或病理结果可疑（n=2）。其余 16 个肿瘤（平均大小 2.6cm；范围 1.8-3.9cm）被纳入我们的研究。仅有 2 个肿瘤显示出不同程度的明显节段性增强，其中 1 个肿瘤存在节段性增强反转。3 个肿块的中央区域呈低密度。在 16 个嗜酸细胞瘤中，有 8 个肿瘤具有最常见的特征，即轻度混杂的肿块，在 CT 后期阶段变得均匀。3 个嗜酸细胞瘤在两个阶段均表现为均匀性。
与之前的报道相反，我们并未发现增强双能 MDCT 上小的肾嗜酸细胞瘤具有节段性增强反转这一特征性增强模式。我们未发现双能 CT 上的任何特定特征可被认为是可靠的，并可强烈提示肾嗜酸细胞瘤的诊断。
