Thoeny Harriet C, Kessler Thomas M, Simon-Zoula Sonia, De Keyzer Frederik, Mohaupt Markus, Studer Urs E, Vermathen Peter
Department of Radiology, Neuroradiology and Nuclear Medicine, University Hospital of Bern, Inselspital, Freiburgstrasse 10, CH-3010 Bern, Switzerland.
Radiology. 2008 Jun;247(3):754-61. doi: 10.1148/radiol.2473070877. Epub 2008 Apr 10.
To prospectively determine if changes in intrarenal oxygenation during acute unilateral ureteral obstruction can be depicted with blood oxygen level-dependent (BOLD) magnetic resonance (MR) imaging.
The study was approved by the local ethics committee, and written informed consent was obtained from all patients. BOLD MR imaging was performed in 10 male patients (mean age, 45 years +/- 17 [standard deviation]; range, 20-73 years) with a distal unilateral ureteral calculus and in 10 healthy age-matched male volunteers to estimate R2*, which is inversely related to tissue Po(2). R2* values were determined in the cortex and medulla of the obstructed and the contralateral nonobstructed kidneys. To reduce external effects on R2*, the R2* ratio between the medulla and cortex was also analyzed. Statistical analysis was performed with nonparametric rank tests. P < .05 was considered to indicate a significant difference.
All patients had significantly lower medullary and cortical R2* values in the obstructed kidney (median R2* in medulla, 10.9 sec(-1) [range, 9.1-14.3 sec(-1)]; median R2* in cortex, 10.4 sec(-1) [range, 9.7-11.3 sec(-1)]) than in the nonobstructed kidney (median R2* in medulla, 17.2 sec(-1) [range, 14.6-23.2 sec(-1)], P = .005; median R2* in cortex, 11.7 sec(-1) [range, 11.0-14.0 sec(-1)], P = .005); values in the obstructed kidneys were also significantly lower than values in the kidneys of healthy control subjects (median R2* in medulla, 16.1 sec(-1) [range, 13.9-18.1 sec(-1)], P < .001; median R2* in cortex, 11.6 sec(-1) [range, 10.5-12.9 sec(-1)], P < .001). R2* ratios in the obstructed kidneys (median, 1.06; range, 0.85-1.27) were significantly lower than those in the nonobstructed kidneys (median, 1.49; range, 1.26-1.71; P = .005) and those in the kidneys of healthy control subjects (median, 1.38; range, 1.23-1.47; P < .001). In contrast, R2* ratios in the nonobstructed kidneys of patients were significantly higher than those in kidneys of healthy control subjects (P = .01).
Increased oxygen content in the renal cortex and medulla occurs with acute unilateral ureteral obstruction, suggesting reduced function of the affected kidney.
前瞻性地确定急性单侧输尿管梗阻期间肾内氧合的变化是否能用血氧水平依赖（BOLD）磁共振（MR）成像来描绘。
本研究经当地伦理委员会批准，所有患者均签署了书面知情同意书。对10例患有远端单侧输尿管结石的男性患者（平均年龄45岁±17[标准差]；范围20 - 73岁）和10例年龄匹配的健康男性志愿者进行BOLD MR成像，以估计与组织氧分压呈负相关的R2*。在梗阻侧肾脏和对侧未梗阻肾脏的皮质和髓质中测定R2值。为减少外部因素对R2的影响，还分析了髓质与皮质之间的R2*比值。采用非参数秩检验进行统计分析。P < 0.05被认为具有显著差异。
所有患者梗阻侧肾脏的髓质和皮质R2值（髓质R2中位数为10.9秒⁻¹[范围9.1 - 14.3秒⁻¹]；皮质R2中位数为10.4秒⁻¹[范围9.7 - 11.3秒⁻¹]）均显著低于未梗阻侧肾脏（髓质R2中位数为17.2秒⁻¹[范围14.6 - 23.2秒⁻¹]，P = 0.005；皮质R2中位数为11.7秒⁻¹[范围11.0 - 14.0秒⁻¹]，P = 0.005）；梗阻侧肾脏的值也显著低于健康对照者肾脏的值（髓质R2中位数为16.1秒⁻¹[范围13.9 - 18.1秒⁻¹]，P < 0.001；皮质R2中位数为11.6秒⁻¹[范围10.5 - 12.9秒⁻¹]，P < 0.001）。梗阻侧肾脏的R2比值（中位数为1.06；范围0.85 - 1.27）显著低于未梗阻侧肾脏（中位数为1.49；范围1.26 - 1.71；P = 0.005）以及健康对照者肾脏的R2比值（中位数为1.38；范围1.23 - 1.47；P < 0.001）。相比之下，患者未梗阻侧肾脏的R2比值显著高于健康对照者肾脏的R2*比值（P = 0.01）。
急性单侧输尿管梗阻时肾皮质和髓质中的氧含量增加，提示患侧肾脏功能降低。
