MR扩散加权成像在慢性肾病诊断中的价值分析

目的 探讨MR扩散加权成像(DWI)在慢性肾病(CKD)诊断中的价值. 资料与方法 对25例CKD患者25例正常人行肾脏DWI,比较分析肾脏表观扩散系数(ADC)值间的差异,分析肾脏ADC值与血清肌酐水平的关系. 结果 正常组双肾ADC值差异无统计学意义;正常组男女志愿者肾脏的ADC值差异无统计学意义.病例组双肾ADC值差异无统计学意义;病例组男女患者肾脏ADC值差异无统计学意义.正常组肾脏ADC值为(2.53±0.24)×10-3 mm2/s,病例组肾脏ADC值为(2.40±0.31)×10-3 mm2/s,两组间肾脏ADC值差异有统计学意义.早期肾功能损害组与正常组肾脏ADC值差异无统计学意义;中晚期肾功能损害组与正常组肾脏ADC值间差异有统计学意义.CKD患者肾脏ADC值与血清肌酐水平呈轻度负相关. 结论 肾脏DWI可用于慢性肾病的诊断,在中期肾功能损害诊断方面具有一定价值.     

MR扩散加权成像在肾功能评价中的应用

目的探讨MR扩散加权成像在肾功能评价中的价值。方法健康志愿者15例作为对照组,慢性肾病(chron ic k idney d isease,CKD)患者32例(其中肌酐正常组12例,肌酐升高组20例)作为研究组。分别测量各例的表观扩散系数(apparent d iffusion coeffic ient,ADC)并与血清肌酐水平及肌酐清除率对比分析。结果15例志愿者在扩散敏感梯度系数(b值)取50、100、400 s/mm2时平均ADC值分别为(405.366±35.964)×10-5mm2/s、(339.646±23.059)×10-5mm2/s、(254.532±13.676)×10-5mm2/s。CKD组病例中肌酐正常组分别ADC值为(336.622±12.879)×10-5mm2/s、(308.142±20.998)×10-5mm2/s、(211.398±14.604)×10-5mm2/s,肌酐升高组分别为(307.717±84.930)×10-5mm2/s、(265.415±57.754)×10-5mm2/s、(201.672±26.411)×10-5mm2/s,ADC值均低于正常对照组(肌酐正常组与正常对照组比较的t值分别为9.720、5.190、11.093,P值均<0.05;肌酐升高组与正常对照组比较的t值分别为6.533、7.382、10.864,P值均<0.05)。肌酐升高组病例的平均血清肌酐水平为(828.490±699.350)μmol/L,肌酐升高组病例的ADC值与血清肌酐水平负相关,但无统计学意义(b值分别为50、100、400 s/mm2时相关系数分别为-0.272、-0.283、-0.023,P值均>0.05)。肌酐升高组病例的平均肌酐清除率为(15.405±14.541)m l/m in,该组病例的ADC值与肌酐清除率呈弱正相关(b值分别为50、100、400 s/mm2时相关系数分别为0.511、0.430、0.335,P值均<0.05,ADC值与肌酐清楚率呈正相关,但相关关系不密切)。结论对肾脏进行扩散加权成像及ADC值测量是1种有一定潜力且无创的肾功能评价的手段。     

MR扩散加权成像在慢性肾病肾功能损害方面的价值研究

目的探讨MR扩散加权成像(DWI)在评价慢性肾病(CKD)肾功能损害方面的价值。资料与方法 CKD患者及正常对照组各57例,采用b值500 s/mm2在屏气情况下进行肾脏冠状面DWI。所有患者及正常对照组均收集血清肌酐水平(SCr)等实验室检查结果。比较病例组与正常对照组肾脏表观扩散系数(ADC)值,并分析患者肾脏ADC值与SCr、肾小球滤过率(GFR)间的相关性。结果 CKD组肾脏ADC值显著低于正常对照组(t=4.466,P<0.01)。病例组双肾间无显著统计学差异。正常对照组与CKD1期患者肾脏ADC值间无显著统计学差异,但与CKD2～5期间具有显著差异(P<0.05)。病例组肾脏ADC值与SCr间呈显著负相关关系(r=-0.449,P=0.001)。病例组肾脏ADC值与肾脏核医学GFR间存在正相关关系(r=0.426,P=0.011)。结论 DWI不但有助于CKD早期肾功能损害的诊断,对于CKD的分期也有一定的价值。     

磁共振扩散加权成像评价胎儿肾脏功能的初步研究

目的：探讨表观扩散系数(ADC)值在正常胎儿肾脏上是否具有规律及特点,为应用磁共振扩散加权成像(DWI)评价胎儿肾脏功能提供正常数据参考。方法对71例经超声和常规 MR 检查均诊断肾脏正常的胎儿进行产前 DWI 扫描,b 值取100、200、500、700 s/mm2,分别统计分析左右肾感兴趣区(ROI)同 b 值、ADC 值差异,单侧肾不同 b 值、ADC 值差异以及双肾平均 ADC值与孕周的相关性。结果除 b=100 s/mm2,左右肾间 ADC 值存在统计学差异,其余各组间比较均无统计学差异。同侧肾不同 b值比较中,除右肾 b=100 s/mm2与 b=700 s/mm2组间比较无统计学意义,其余各组间比较均有统计学意义。同时随孕周增大,双肾 ADC 值均呈下降趋势。结论DWI 评价胎儿肾脏发育是可行的,不同 b 值得到的 ADC 值可作为定量参数评估正常胎儿肾脏发育情况。     

应用磁共振扩散加权成像评价梗阻性黄疸的初步研究

目的探讨磁共振扩散加权成像(d iffusion-we ighted im aging,DW I)评价梗阻性黄疸的可行性。方法25例梗阻性胆管扩张的患者,根据血清总胆红素水平升高与否分为有黄疸组(14例)和无黄疸组(11例),对照组为11例健康志愿者,行DW I检查,测量3组肝脏的表观扩散系数(apparent d iffusion coeffic ient,ADC)值并比较其差异。结果b值差为500 s/mm2时,各组间肝脏ADC值有统计学差异(F=25.29,P<0.01),经两两比较,有黄疸组的肝脏ADC值[(1.37±0.11)×10-3mm2/s]显著低于(P<0.01)无黄疸组[(1.63±0.14)×10-3mm2/s]和对照组[(1.67±0.08)×10-3mm2/s],无黄疸组与对照组间肝脏ADC值无显著性差异(P>0.05)。b值差为300 s/mm2时,各组间肝脏ADC值有统计学差异(F=12.22,P<0.01),经两两比较,每2组间肝脏ADC值差异均有显著性,有黄疸组[(1.58±0.21)×10-3mm2/s]低于(P<0.05)无黄疸组[(1.78±0.19)×10-3mm2/s]和对照组[(1.94±0.13)×10-3mm2/s],无黄疸组低于对照组(P=0.047)。结论肝脏ADC值测量有可能用于评价肝脏的功能。     

RESOLVE序列ADC值在宫颈癌诊断中的价值

目的 初步探讨分段读出扩散加权成像(RESOLVE)序列表观扩散系数(ADC)值在宫颈癌诊断中的应用价值.方法 经宫颈活检或手术病理证实的宫颈癌患者69例为病例组,同时选取正常宫颈组织40例为对照组,所有病例均行T1WI、T2WI及RESOLVE序列扫描(b=0、800 s/mm2),分别测量宫颈癌及正常子宫颈ADC值.对所得数据进行统计学分析.结果 宫颈癌病灶和正常宫颈的平均ADC值分别为(0.86±0.13)×10-3 mm2/s、(1.68±0.04)×10-3 mm2/s,两者差异有统计学意义(P＜0.05).宫颈鳞癌、腺癌平均ADC值分别为(0.84±0.12)×10-3 mm2/s、(0.98±0.18)×10-3 mm2/s,两者差异有统计学意义(P＜0.05).宫颈鳞癌高分化组(G1)、中分化组(G2)及低分化组(G3)平均ADC值分别为(0.97±0.13)×10-3 mm2/s、(0.83±0.14)×10-3mm2/s、(0.79±0.09)×10-3 mm2/s,G1、G2组间及G1、G3组间ADC值差异均有统计学意义,G2、G3组间ADC值无统计学差异;ADC值与病理分化程度之间呈负相关(r=-0.435,P＜0.05).结论 RESOLVE序列ADC值在宫颈癌的诊断、病理分类及分化程度中具有一定的应用价值.     

慢性肾脏病的皮髓质ADC值与肾脏功能及病理的相关性研究

目的探讨慢性肾脏病(chronic kidney disease,CKD)患者的皮髓质表观扩散系数(apparent diffusion coef-ficient,ADC)变化规律及其与肾脏功能及病理改变的相关性。资料与方法对临床诊断并接受肾脏穿刺活检的21例CKD患者(CKD组)和27名健康志愿者(对照组)均行常规MRI和扩散加权成像(DWI),b值取0、500 s/mm2和0、1000 s/mm2两组,测量健康志愿者与CKD患者的肾脏皮髓质ADC值,并分析皮髓质ADC值与肾脏功能指标及小管间质损伤程度之间的相关性。结果 CKD患者的肾脏皮髓质ADC500、ADC1000值均显著低于正常对照组(P<0.001)。CKD患者的皮髓质ADC1000值与肾小球滤过率估算值(eGFR)均呈正相关(P<0.01),皮质ADC500、ADC1000值与CKD分期呈负相关(P<0.05)。CKD患者的皮髓质ADC500、ADC1000值与小管间质损伤评分均呈负相关(P<0.05),以皮质ADC1000值为著(P<0.01)。结论肾脏皮髓质ADC值能在一定程度上反映CKD患者的肾脏功能及小管间质损伤程度,以皮质ADC1000值最敏感。     

肝纤维化和肝硬化的MR扩散成像及与病理对照、CT灌注参数的相关性研究

目的利用扩散加权成像(DWI)检查技术测定肝纤维化和肝硬化患者表观扩散系数(ADC)值并与正常对照组及相应病理对照来反映肝纤维化程度,同时分析其与血流动力学指标的相关性。资料与方法分别对44例肝纤维化患者、49例肝硬化患者及46名正常对照者利用DWI(b=500s/mm2)技术进行ADC值测定,并与病理改变及CT灌注参数作对照研究。结果肝纤维化组、肝硬化组ADC值降低;对照组、S2、S3组ADC值逐渐降低;Child-PughA、B、C分级组中ADC值无差别;肝纤维化不同分级与Child-PughA、B、C分级组中S3组ADC值降低而ChildC组ADC升高;对照组及肝纤维化组ADC值均与CT灌注参数间无相关性;肝硬化组ADC值与CT灌注参数(BV、BF)正相关。结论b值为500s/mm2时可显示肝纤维化及肝硬化患者ADC值降低,肝硬化患者ADC值较肝纤维化患者ADC值升高与肝血流量增加有关。     

正常成人肾脏磁共振扩散加权成像研究

目的 通过测量正常成人肾脏磁共振扩散加权成像(DWI)时的表观弥散系数(ADC)值,为肾脏病变患者在DWI成像时提供正常对照标准.资料与方法 20例健康志愿者均行MRI常规平扫及DWI成像,DWI成像时b值分别采用0s/mm2、200s/mm2、500s/mm2、800s/mm2、1000s/mm2.结果 不同b值下双侧肾脏皮髓质ADC值及双侧肾脏平均ADC值差异有统计学意义(F=57.863～240.324,P=0.000),双侧肾脏皮髓质ADC值及平均ADC值均高于肝、脾及胰腺ADC值.双侧肾脏皮质在不同b值下的ADC值均高于髓质,差异有统计学意义(t=8.436～20.281,P=0.000).左侧肾脏皮、髓质ADC值及平均ADC值在b=500s/mm2、b=800s/mm2及1000s/mm2时均高于右侧,差异有统计学意义(b=800s/mm2时t=2.023,P=0.048;其余P=0.000).b=200s/mm2时双侧肾脏皮、髓质ADC值及平均ADC值之间差异无统计学意义(t=1.739,P=0.098;t=0.704,P=0.490;t=-0.314,P=0.757).结论 正常成人肾脏ADC值在不同b值下有差异,双侧肾脏平均ADC值亦存在差异.     

磁共振扩散成像在慢性肾病中的初步研究

目的探讨磁共振扩散加权成像在慢性肾病中的应用价值。方法将10例健康志愿者和45例不同分期的慢性肾病患者(包括慢性肾病肌酐正常者10例,慢性肾衰肾功能代偿者9例,慢性肾衰肾功能失代偿者9例,慢性肾功能衰竭者8例及慢性肾衰尿毒症者9例)进行常规肾脏磁共振检查和扩散加权成像检查。观察分析其扩散成像的影像学表现,使用系统软件包在ADC图上直接测量肾脏的ADC值。结果慢性肾病肾脏的ADC值(×10-3mm2/s)在b值为300、500、800s/mm2时分别为2.29±0.27、2.07±0.21、1.91±0.22,均明显低于正常对照组肾脏ADC值;慢性肾病不同分期患者肾脏ADC值之间可能有差异。结论DWI可以作为临床评价肾脏功能的一种无创检查手段。     

3T MR DW和BOLD对移植肾初步研究

目的:研究3.0T MR对移植肾DWI和BOLD成像的可行性.初步设定在3.0T MR上正常自体肾和正常移植肾的ADC值和R2*值范围.对比慢性移植肾病的ADC和R2*值,希望能无创性地加以鉴别.方法:对16例正常人及16例肾移植患者(8例为正常移植肾,8例慢性移植肾病)进行DWI和BOLD功能成像,在工作站上分别进行皮质和髓质ROI的定位,并记录ADC值和R2*值,对所得的结果进行统计学分析.结果:在3.0T MR上肾脏DWI和BOLD图像信噪比良好,能满足成像要求.自体肾和正常移植肾的皮髓质ADC值和R2*值的基线和变化范围均较以前报道的在1.5T上获得的高.慢性移植肾病的皮质ADC值、髓质R2*值及髓皮质R2*比值均较正常移植肾降低,并且有统计学意义.结论:3.0T MR扫描仪对肾脏DWI和BOLD功能成像是可行的,并且有利于对肾脏的功能研究,对慢性移植肾病的鉴别有一定帮助.     

DTI量化评估慢性肾脏病患者肾功能状态及损伤程度的价值

目的探讨扩散张量成像(diffusion tensor imaging,DTI)量化对慢性肾脏病(chronic kidney disease,CKD)患者肾功能状态及肾功能损伤程度的临床预测价值。方法选取本院诊治的轻度(1~2期)CKD患者43例为轻度组,中重度(3~5期)CKD患者45例为中重度组,同期体检健康者50例为健康对照组。比较三组DTI相关参数各向异性分数(fractional anisotropy,FA)及表观弥散系数(apparentdiffusion coefficient,ADC)水平与肾功能指标的相关性;评估DTI量化指标对CKD肾功能及肾损伤的预测价值。结果三组皮质和髓质ADC值与FA值水平比较差异有统计学意义(P<0.05)且皮质和髓质ADC、FA值对照组>轻度组>重度组。三组肾功能指标比较差异有统计学意义(P<0.05),Scr、24h-Upro水平对照组<轻度组<重度组,eGFR水平对照组>轻度组>重度组。相关分析显示,皮质和髓质的ADC和FA值与均Scr、24h-Upro呈负相关,与eGFR呈正相关(P<0.05)。ROC曲线显示,髓质FA预测中重度CKD具有一定准确性(AUC=0.852,敏感度、特异度为82.2%、79.8%)。结论DTI量化相关参数对CKD,患者肾功能状态及损伤程度具有重要的预测价值。     

肾动态显像分次处理法定量评价肾脏局部功能

目的 :明确正常情况下及不同肾脏疾病时 ,肾脏各部分对 99m　Tc DTPA浓聚及清除速度的差别与特点 ,以定量评价肾脏各部分的局部功能状态。方法 :对 18例正常对照、74例不同肾病患者进行了肾动态显像 ,并应用常规肾动态处理软件及ROI技术分别对全肾、肾皮质、肾盂肾盏作了定量分析 ,获得肾脏各部分的Tb、C1/2及 2 0min残留率。结果 :在无肾脏疾病的正常对照组 ,全肾与肾皮质、肾盂肾盏部分之间的定量分析指标均无明显差别 ,在疾病组 ,肾脏各部分的指标则有不同程度的改变 ,尤其是在糖尿病、慢性肾炎及肾盂肾炎的患侧肾差异更明显 ,表现为肾盂肾盏部分的Tb延长。全肾、肾皮质和肾盂肾盏的Tb均值在糖尿病分别为 5 .8min、4.5min和 6.8min(P <0 .0 1) ;慢性肾炎为 7.9min、6.3min和 9.1min(P <0 .0 5 ) ;肾盂肾炎为 6.0min、4.0min和 7.6min(P <0 .0 5 ) ;在高血压病患者三者无显著差异。而在 13例有上尿路排泄不畅的患者 ,三种处理方法时 ,Tb、C1/2及 2 0min残留率均有差异 (P <0 .0 5～ 0 .0 0 1)。结论 :定量评价肾脏各部分的功能对于正确反映和认识肾功能受损程度及其部位有参考价值 ,尤其适用于尿路排泄不畅患者的肾功能估计     

正常成人肾脏水分子扩散加权成像的研究

目的定量研究正常成人肾脏水分子扩散的特性并探讨其发生机制。方法用平面回波成像(EPI)技术对63例健康正常人的腹部实质器官(肝、脾、肾及胰腺)分别行磁共振扩散加权成像(DW I)并测量各自的表观扩散系数(ADC)。结果肾脏髓质的ADC值最高,肾脏的ADC值(包括皮质及髓质)明显高于腹部其它实质器官的ADC值(P<0.05);肾髓质的ADC值在不同扩散敏感梯度方向上存在统计学差异(P<0.05)。结论肾脏组织内水分子扩散表现为各向异性,其高ADC值与肾脏的含水量、水分子转运及血流灌注相关。     

IVIM-MRI监测白兔肾积水肾功能损害的研究

目的 探讨体素内不相干运动磁共振成像(IVIM-MRI)监测肾积水肾功能改变的价值.方法 动态分析新西兰大白兔左侧输尿管不全梗阻肾积水模型成模后4、8、12、16周的左肾IVIM-MRI定量参数[表观扩散系数(ADC)值、纯扩散系数(D)值、假性扩散系数(D*)值、灌注分数(f)值]变化特点,并将该参数与核素肾小球滤过率(GFR)值做相关分析.结果 成模后4、8、12、16周白兔左侧积水肾的皮髓质D值、D*值、f值、ADC值随着肾功能受损程度加重数值逐步下降,其中D值、f值及ADC值组间两两LSD对比:12周、16周与对照组、4周,8周与16周组间差异有统计学意义(P<0.05);D*值组间两两LSD对比:8周、12周、16周与对照组、4周,12周、16周与8周间差异有统计学意义(P<0.05);左侧积水肾成模后不同时间点的D值、D*值、f值、ADC值与核素GFR呈中度正相关.结论 IVIM-MRI能有效动态监测肾积水肾功能的变化.     

Assessment of early renal allograft dysfunction with blood oxygenation level-dependent MRI and diffusion-weighted imaging

PurposeTo investigate blood oxygenation level-dependent (BOLD) MRI and diffusion-weighted imaging (DWI) at 3 T for assessment of early renal allograft dysfunction.Materials and methods34 patients with a renal allograft (early dysfunction, 24; normal, 10) were prospectively enrolled. BOLD MRI and DWI were performed at 3 T. R2* and apparent diffusion coefficient (ADC) values were measured in cortex and medulla of the allografts. Correlation between R2* or ADC values and estimated glomerular filtration rate (eGFR) was investigated. R2* or ADC values were compared among acute rejection (AR), acute tubular necrosis (ATN) and normal function.ResultsIn all renal allografts, cortical or medullary R2* and ADC values were moderately correlated with eGFR (P < 0.05). Early dysfunction group showed lower R2* and ADC values than normal function group (P < 0.05). AR or ATN had lower R2* values than normal allografts (P < 0.05), and ARs had lower cortical ADC values than normal allografts (P < 0.05). No significant difference of R2* or ADC values was found between AR and ATN (P > 0.05).ConclusionBOLD MRI and DWI at 3 T may demonstrate early functional state of renal allografts, but may be limited in characterizing a cause of early renal allograft dysfunction. Further studies are needed.     

Diffusion-weighted imaging in assessing renal pathology of chronic kidney disease: A preliminary clinical study

Objective

To investigate the clinical potential of diffusion-weighted imaging (DWI) in assessing renal pathology of chronic kidney disease (CKD).

Methods

Seventy-one CKD patients and twelve healthy volunteers were examined using DWI with prospective acquisition correction. Renal biopsy specimens from the CKD patients were scored based on the severity of renal pathology and to confirm pathology type. CKD patients were divided into three groups according to pathology scores: mild, moderate, or severe. The association between renal apparent diffusion coefficient (ADC) values and pathology scores was investigated using Pearson's correlation and single factor analysis of variance. Multiple linear regression analysis was performed to explore associations between renal ADC values and pathology score, glomerular filtration rate, serum creatinine, and age. The Kruskal–Wallis H test was conducted to compare ADC values and pathology type.

Results

Renal ADC values correlated negatively with pathology scores (r = −0.633, P < 0.001). The ADC values among the four groups (mild, moderate, severe impairment, and controls) were significantly different (F = 19.512, P < 0.001). However, when patients were stratified by pathology type, no significant differences were found in ADC values among these groups (χ² = 9.929, P = 0.270). Further multiple linear regression analysis showed that only the pathology score and ADC values were related (t = −4.586, P = 0.000).

Conclusions

DWI has clinical potential in assessing the severity of renal pathology in CKD and shows promise as a non-invasive and effective technique to guide therapy and follow-up.     

Diffusion-weighted MR imaging of kidneys in healthy volunteers and patients with parenchymal diseases: initial experience

PURPOSE: To prospectively evaluate feasibility of diffusion-weighted (DW) magnetic resonance (MR) imaging in assessment of renal function in healthy volunteers and patients with various renal abnormalities and to prospectively evaluate reproducibility of DW MR imaging in volunteers. MATERIALS AND METHODS: Study protocol was approved by local ethics committee; informed consent was obtained. Eighteen healthy volunteers and 15 patients underwent transverse fat-saturated echo-planar DW MR imaging of the kidneys during normal breathing. Freehand regions of interest were delineated in the cortex and medulla of the kidneys. The following apparent diffusion coefficient (ADC) values were calculated: ADC of all b values (ADC(avg)), ADC of low b values (b = 0, 50, 100 sec/mm2; ADC(low)), and ADC of high b values (b = 500, 750, 1000 sec/mm2; ADC(high)). These values were calculated to differentiate influence of perfusion and diffusion. Reproducibility was assessed by repeating the same protocol in five randomly selected volunteers after 6 months. For statistical analysis, Student t tests were used. RESULTS: In all volunteers, ADC(avg) and ADC(high) were significantly higher in the cortex than in the medulla (P < .001). No difference between the cortex and medulla could be observed for ADC(low). Patients with renal failure had significantly lower ADC(avg) (P < .001, P = .004), ADC(low) (P = .02, P = .03), and ADC(high) (P = .02, P = .04) of cortex and medulla, respectively, than did volunteers. In the patient with pyelonephritis, all ADC values of cortex and medulla were substantially lower compared with the contralateral side, whereas patients with ureteral obstruction showed varying degrees of difference in all ADC values compared with the contralateral side. No statistically significant changes were found in the repeat study of the volunteers. CONCLUSION: DW MR imaging is feasible and reproducible in the assessment of renal function, as shown in our initial experience with a small number of patients and volunteers.     

Functional evaluation of hydronephrosis by diffusion-weighted MR imaging. Relationship between apparent diffusion coefficient and split glomerular filtration rate

PURPOSE: To determine the relationship between apparent diffusion coefficient (ADC) values measured by diffusion-weighted MR imaging and split renal function determined by renal scintigraphy in patients with hydronephrosis. MATERIAL AND METHODS: Diffusion-weighted imaging on a 1.5 T MR unit and renal scintigraphy were performed in 36 patients with hydronephrosis (45 hydronephrotic kidneys, 21 non-hydronephrotic kidneys). ADC values of the individual kidneys were measured by diffusion-weighted MR imaging. Split renal function (glomerular filtration rate (GFR)) was determined by renal scintigraphy using 99mTc-DTPA. The relationship between ADC values and split GFR was examined in 66 kidneys. The hydronephrotic kidneys were further classified into three groups (severe renal dysfunction, GFR <10 ml/min, n=7; moderate renal dysfunction, GFR 10-25 ml/min, n= 10; normal renal function, GFR >25 ml/ min, n=28), and mean values for ADCs were calculated. RESULTS: In hydronephrotic kidneys, there was a moderate positive correlation between ADC values and split GFR (R2=0.56). On the other hand, in nonhydronephrotic kidneys, poor correlation between ADC values and split GFR was observed (R2=0.08). The mean values for ADCs of the dysfunctioning hydronephrotic kidneys (severe renal dysfunction, 1.32 x 10(-3) +/- 0.18 x 10(-3) mm2/s; moderate renal dysfunction, 1.38 x 10(-3) +/- 0.10 x 10(-3) mm2/s) were significantly lower than that of the normal functioning hydronephrotic kidneys (1.63 x 10(-3) +/- 0.12 +/- 10(-3) mm2/s). CONCLUSION: These results indicated that measurement of ADC values by diffusion-weighted MR imaging has a potential value in the evaluation of the functional status of hydronephrotic kidneys.