八例肾球旁细胞瘤的CT、MRI表现及临床特征分析

The CT and MRI manifestations and clinical features of 8 cases of juxtaglomerular cell tumor

目的：探讨肾球旁细胞瘤（JGCT）的CT、MRI表现及临床特征。方法回顾性分析经手术切除并经病理证实的8例JGCT患者资料。7例术前行CT检查，其中5例行CT平扫及动态增强扫描，2例行平扫；8例行MRI平扫及动态增强扫描。观察患者的临床表现，是否有高血压和血钾减低，记录卧立位试验结果并分段肾静脉取血测肾素水平。记录患者的CT、MRI表现。结果（1）临床特征：8例均出现高血压，5例出现血钾减低。7例行卧立位试验的患者中，6例立位肾素活性升高，7例立位血管紧张素Ⅱ和醛固酮水平均增高。4例行经肾静脉分段取血测量肾素水平，1例肾素活性结果阳性。（2）影像表现：8例肿瘤均为单发，边界清楚，最大径1.9～3.8 cm，中位值2.7 cm。CT平扫均无钙化及假包膜，等密度4例，稍高密度1例，低密度伴点片状稍高密度1例，低密度1例；增强扫描4例皮质期、髓质期持续强化，1例无明显强化。MRI检查T2WI表现：假包膜6例，6例信号不均（高信号伴少许低信号4例，低信号伴少许高信号2例），2例信号均匀（等、高信号各1例）；T1WI表现：2例低信号，2例等信号，4例混杂信号；DWI表现：均匀或晕环、结节样高信号；增强扫描：7例呈渐进式强化，1例延迟期廓清。结论 JGCT具有较特异的临床及影像表现，二者结合有助于正确诊断。

Objective To explore the CT and MRI manifestations and clinical features of juxtaglomerular cell tumor （JGCT）. Methods A retrospective analysis the data of eight JGCT patients who resected by surgery and comfirmed by histopathology. Seven cases were examined by CT before operation, five of whom underwent CT scan and dynamic enhanced scan, two of whom underwent CT scan, and all of the eight underwent MRI scan and dynamic enhanced scan. The clinical manifestations of patients were also observed, whether they have hypertension and reduced blood potassium, recorded the results of lying and standing test, and collected the segmental renal vein blood to detect the renin levels. Meanwhile, the CT and MRI manifestations were also recorded. Results （1） We found that all of the eight patients appeared hypertension, and hypokalemia were found among five cases. Seven patients proceeded the lying and standing test, six of whom the plasma renin activity （PRA） were elevate in erect position, and the levels of angiotensin Ⅱand aldosterone （ALD） were rised among all of the seven cases in erect position. Four patients were collected the segmental renal vein blood, and one of whom has positive result of the renin activity. （2） The tumors of all the eight cases were single, the border was clear, and the average size was 2.7 cm （range 1.9 to 3.8 cm）. The CT scan results showed there＇s no calcification or pseudocapsule were detected, four cases showed homogeneous iso-density, one case with slightly high density, another one showed low density with dotty high density and one case with low density. The dynamic enhanced CT scan showed that four cases performed continuous enhancement from cortical to medullary phase, and no obvious＆amp;nbsp;enhancement was found in one case. The T2WI results of MRI scan showed six cases had pseudocapsule, 6 cases had heterogeneous signal （4 cases with patchy low signal and 2 cases with patchy high signal）, and 2 cases had homogeneous signal （one case with iso-high signal and another with high signal）. The T1WI results showed two cases performed low signal, anther two cases showed iso-signal, and four cases with heterogeneous signal. The DWI results showed all of the 8 lesions with homo-or peripheral high signal. The dynamic enhanced MRI scan results showed seven cases performed gradual enhancement, and the border of another case became clear on delay phase. Conclusions JGCT has specific clinical and imaging features, and the combination will help make a correct diagnosis.