Del Viscovo L, Ginolfi F, Rotondo A, Smaltino F
Istituto di Scienze Radiologiche (II Cattedra), Facoltà di Medicina e Chirurgia, Università degli studi di Napoli Federico II.
Radiol Med. 1993 Dec;86(6):847-50.
MR examinations were performed on 16 patients with small (< 35 mm diameter) solid renal tumors previously diagnosed with US and/or CT. The study was aimed at assessing MR accuracy in the identification and characterization of this type of lesion. The studies were performed with a 0.5 T GE MR Max Plus unit, with no paramagnetic contrast medium administration. MRI detected the lesion in 15 cases (93.7%). In 3/15 patients (18.7%) the tumors had signal patterns similar to those of simple renal cysts--i.e., homogeneously hypointense on T1 and markedly hyperintense on T2-weighted images. In one patient (6.2%) MRI failed to detect the lesion. In the extant 12 cases the tumors were correctly demonstrated but had different signal patterns. On T1-weighted images 6 lesions were hypointense, 2 hyperintense because of hemorrhagic content, and 4 exhibited poor contrast with the surrounding renal parenchyma. On T2-weighted images 4 lesions were inhomogeneously hyperintense, 3 were hypointense because of fibrosis or old blood content, and in 5 cases contrast between the tumor and the renal parenchyma was poor. The authors conclude that T1-weighted MR images, in a midfield MR unit, are more sensitive than T2-weighted images in identifying small renal tumors. MRI is less accurate in the evaluation of these lesions than CT and US. In particular, since small renal lesions may be misdiagnosed as simple cysts, the use of other imaging modalities--e.g., US and CT--is recommended if a renal cyst is first identified on MR images.
对16例先前经超声和/或CT诊断为小（直径<35mm）实性肾肿瘤的患者进行了磁共振（MR）检查。该研究旨在评估MR在这类病变的识别和特征描述方面的准确性。研究使用0.5T的GE MR Max Plus设备进行，未使用顺磁性造影剂。MRI在15例（93.7%）中检测到病变。在15例患者中的3例（18.7%），肿瘤的信号模式与单纯肾囊肿相似，即在T1加权像上呈均匀低信号，在T2加权像上呈明显高信号。1例患者（6.2%）MRI未能检测到病变。在其余12例中，肿瘤被正确显示但信号模式不同。在T1加权像上，6个病变呈低信号，2个因出血成分呈高信号，4个与周围肾实质对比不佳。在T2加权像上，4个病变呈不均匀高信号，3个因纤维化或陈旧性血液成分呈低信号，5例肿瘤与肾实质之间对比不佳。作者得出结论，在中场MR设备中，T1加权MR图像在识别小肾肿瘤方面比T2加权图像更敏感。MRI在评估这些病变方面不如CT和超声准确。特别是，由于小肾病变可能被误诊为单纯囊肿，如果在MR图像上首先识别出肾囊肿，建议使用其他成像方式，如超声和CT。
