Heuer Roman, Sommer Graham, Shortliffe Linda D
Department of Urology, Stanford University School of Medicine, California 94305, USA.
J Urol. 2003 Oct;170(4 Pt 2):1659-63; discussion 1663. doi: 10.1097/01.ju.0000085676.76111.27.
Magnetic resonance imaging (MRI) and computerized tomography (CT) are commonly used to image complex medical conditions but limited data have been reported concerning normal renal volumetric measurement with these imaging techniques. We examined whether normative renal growth curves could be constructed from data derived from these imaging modalities, and from these curves assessed normal and abnormal renal development.
Patients who had undergone prior renal MRI or CT were identified. Total renal volume and renal cortical fraction (CF, cortical/total volume) were calculated, and growth curves were derived. To examine the curve utility for abnormal growth assessment, renal ultrasonography of children with reflux nephropathy was examined, and MRI and radionuclide scans were compared.
A total of 60 patients 2 months to 39 years old who underwent MRI were included in the growth curve. The CF of the 120 kidneys was 75.8 +/- 4.3% and independent of sex and age. In 19 patients with vesicoureteral reflux 13 kidneys had cortical scarring, and the CF was decreased (p <0.001, 63.65 +/- 5.72%), indicating disproportionate cortical loss. No difference between CF for normal and vesicoureteral reflux unscarred kidneys was found. Differential renal function on radionuclide study correlated highly with MRI renal volume (r = 0.91). CT was performed in 70 children 1 to 15 years old (mean age 7.9) volume correlated with age and renal length, and the left kidney was larger than right kidney on MRI and CT.
Normative renal growth curves can be constructed from CT and MRI derived renal volumes. Cortical fraction is consistent, and sex and age independent. In reflux nephropathy the CF is reduced and renal differential function on nuclear scan correlates with MRI derived differential volume. This concept may be useful for predicting abnormal renal growth and differential function.
磁共振成像（MRI）和计算机断层扫描（CT）常用于对复杂医疗状况进行成像，但关于使用这些成像技术进行正常肾脏容积测量的报道数据有限。我们研究了是否可以根据这些成像方式获得的数据构建正常肾脏生长曲线，并通过这些曲线评估正常和异常的肾脏发育情况。
确定曾接受过肾脏MRI或CT检查的患者。计算总肾体积和肾皮质分数（CF，皮质体积/总体积），并得出生长曲线。为了检验该曲线在异常生长评估中的效用，对患有反流性肾病儿童的肾脏超声检查结果进行了研究，并比较了MRI和放射性核素扫描结果。
共有60例年龄在2个月至39岁之间接受MRI检查的患者被纳入生长曲线研究。120个肾脏的CF为75.8±4.3%，且与性别和年龄无关。在19例膀胱输尿管反流患者中，13个肾脏有皮质瘢痕形成，CF降低（p<0.001，63.65±5.72%），表明皮质损失不成比例。未发现正常肾脏与无瘢痕膀胱输尿管反流肾脏的CF有差异。放射性核素研究中的分肾功能与MRI肾体积高度相关（r=0.91）。对70例年龄在1至15岁（平均年龄7.9岁）的儿童进行了CT检查，体积与年龄和肾长度相关，且在MRI和CT上左肾均大于右肾。
可根据CT和MRI得出的肾体积构建正常肾脏生长曲线。皮质分数是一致的，且与性别和年龄无关。在反流性肾病中，CF降低，核素扫描的分肾功能与MRI得出的分体积相关。这一概念可能有助于预测异常肾脏生长和分肾功能。
