【作者】 孟然；

【导师】 文建国；

【作者基本信息】 郑州大学 ， 外科学， 2004， 硕士

【摘要】 背景和目的：泌尿系统结核、结石、肿瘤及损伤等是成人梗阻性肾脏疾病的常见原因，儿童则以先天性因素居多，常见病因包括先天性肾盂输尿管连接部狭窄(PUJO)、高位肾盂输尿管、异位血管(迷走血管)压迫等。泌尿系任何部位的梗阻，最后均将出现肾功能丧失。因此，肾脏梗阻的早期诊断和治疗非常重要。由结石和肿瘤等引起的狭窄，伴随症状常较明显，加之B超、CT、IVU(静脉尿路造影)的广泛应用，诊断并不困难。儿童肾积水，尤其是先天性肾积水，早期症状常不十分明显，患儿往往无任何自觉症状。现有的影像学诊断技术(如B超、IVU等)无法在病变初期形态变化不甚显著时判断是否存在梗阻性肾积水或非梗阻性肾积水。如何发展一种方法既能了解积水肾脏形态和功能，又能对泌尿系梗阻作出早期诊断，特别是婴幼儿或先天性肾积水早期的诊断方法，是临床亟待解决的课题。采用Gd-DTPA增强动态MRI能了解肾脏血流变化以及分泌和浓缩稀释功能。动物研究显示Gd-DTPA引起肾脏信号强度(signal intensity，SI)的特征性变化和正常及梗阻肾脏的解剖、功能状态完全一致：提示此项技术可用于诊断梗阻性肾脏疾病并提供肾功能变化信息。如果SI发生变化，则预示肾脏血流量及肾小管的稀释和浓缩功能发生改变，从而通过观察对比剂(Gd-DTPA)经过肾脏的各个部位产生的信号强度变化，从形态和功能两个方面来评价肾脏损害。本研究拟应用动态增强MRI技术，了解正常肾脏和梗阻肾脏的形态和功能，探讨不同程度梗阻对肾脏功能的损害，评价动态增强MRI对梗阻性肾脏病变的诊断价值。 材料与方法：选择8例临床上已被确诊的肾积水患者(均为单侧)，其中成人2例，儿童6例，6例儿童病人经手术证实病因均为先天性肾盂输尿管连接部狭窄。全部病人均为男性，年龄4—57岁，平均23岁，作为病人组；基于医郑州大学2004届硕士研究生毕业论文(摘要部分)正常和梗阻肾脏动态增强MRI研究学伦理，另外选择8例成年健康志愿者(16个正常肾脏)作为对照组，包括7例男性和1例女性，年龄22一34岁，平均28.5岁。另外，7例儿童肾积水患儿的积水对侧肾脏作为评价儿童肾积水的对照，因客观实验条件和医学伦理限制，无法以正常健康小儿作为对照，所以均以对侧肾脏作为对照，且在实施此项检查之前，己经各项生化检测和WU、核素肾图评估，所有对侧肾脏肾功能均在正常范围内，7例病因均为PUJO。 MRI采用西门子公司1.OTesla MR机(Impaet)和体线圈，MRI对比剂使用奈科明爱尔兰有限公司生产的非离子型顺磁性造影剂欧乃影(Gd一DTPA)。平扫和增强时，病人采用仰卧位，均以冠状面TI加权成像，设定TR(脉冲重复时间)为40Oms，TE(回波时间)为15ms，层厚smm，采集13层，矩阵256x256，扫描野350一450mm，采集次数(Acq)2次，必要时可加扫轴位像。在对各组肾脏进行平扫的基础上，运用动态增强MRI技术，在注射对比剂后的lmin、3min、smin、10min、15min、30min、45min和60min这8个时间点，分别选取每帧图像的肾皮质、肾髓质和肾盂的部分区域作为感兴趣区(ROI)，计算不同时间段不同感兴趣区的SI，对肾脏的功能状态进行评估。得出相对信号强度(relative 51，Rsl，Rsl=posts帅resl)，采用重复数据测量的方差分析，分别比较各组内每个时间点之间有无差异和两组间的RSI值，按Q二0.05标准评价，绘制出时间一信号强度变化曲线(T一SI曲线)，对肾脏的功能状态进行评估。 结果:1.MRI平扫结果:正常肾脏于T:加权时，皮质信号较髓质稍高。肾脏在平扫时，皮质SI平均618.7，髓质平均508.6，肾盂平均519.8。积水肾脏的实质部分SI与正常肾脏差别不显著，但积水的肾盂因含水量较大，呈长TI信号，51较对照组更低，平均177.7(P<0.05)。2.动态增强MRI扫描结果:正常肾脏在注药后10秒内肾皮质被强化，20一50秒后信号达最高值，继之缓慢下降;近30秒时强化至髓质，且髓质强化水平较皮质高，1分钟内即可见到少量对比剂排泄至肾盂，使其信号强度逐渐升高:而后SI值呈平滑曲线缓慢下降;梗阻肾脏的对比剂排泄明显减慢，T一SI曲线上升段变缓，下降段波度变小，积水严重的肾脏可维持在平台期至60郑州大学2004届硕士研究生毕业论文(摘要部分)正常和梗阻肾脏动态增强MRI研究分钟时仍无变化;对照组和积水组RSI均值，采用重复数据测量的方差分析，发现各组内每个时间点两两比较均有显著性差异(P<0 .05)，两组间(肾实质和集合系统)的T一SI曲线，具有明显差异(P<0.05)。8例患者术中所见病理改变与分析结果一致。儿童组中积水肾脏组与对侧肾脏组相比组内(各时间点)与组间均有显著性差异(P<0.05)。结论:(1)应用Gd一DTPA动态增强MRI可以采集肾脏不同时间和区域的Sl，在无创、安全的环境下评估肾脏形态和功能的改变。(2)通过观察肾脏信号强度的改变，可能提供肾脏浓缩机制的定量信息，在肾皮质、髓质、肾盂和集合系统中SI的明显增加或减少可提示出肾脏梗阻的程度和对肾脏损害的水平。有利于对梗阻肾脏的形态和功能变化进行联合评估。(3)作为对先天性肾孟输尿管连接部狭窄所致肾积水的筛选性诊断方法，可在早期发现肾功能的轻微改变，并发更多还原

【Abstract】 Background and objective: Urological tuberculosis , tumor m calculus and trauma,etc.are frequently confronted factors that related to obstructive nephropathy, especially in adult patients. The renal dysfunction will emerge finally if, anyhow, the diagnosis and treatment could not be settled as soon as possible. In children, the most etiology of obstructive is congenital abnormity including congenital pelvic ureter junction obstruction(PUJO) and neugenic bladder, although the calculus and tumor are also frequently confronted. The diagnosis for the stenosis resulting from calculus and tumor is relative easy due to not only they had obvious apparent symptoms but also the ultrasonography, CT, intravenous urography(IVU) is pubular and precious in making diagnosis.. However, the evaluation of congenital hydronephrosis is facing the challenges. With ultrasound used popularly, more and more congenital hydronephrosis had been found, even in infant with no any clinical symptoms.The techniques routinely used in the clinics can not give forecast and whether exists of obstuctive hydronephrosis or non-obstuctive hydronephrosis, and when thesignificant pathological change of the kidney will occur. How to develop a modality to evaluate not only the figuration but also function, especially the individual kidney function regarding the concentrate and diluate ability, and to predict the prognosis, and to make sure if exist significan ureteral obstruction is a vital research dirction. MRI Gd-DTPA enhanced dynamics urography adopt fast gradient echo sequence to collect renal signal and can be used to know renal bloodflow variance and other renal function including excretion, concentration and dilution. By animal research, we had discovered that some special changes of signal intensity(SI) by Gd-DTPA in certain given region were coincident with functional estate of normal and obstructive kidney indicating this technique can diagnose obstructive nephropathy and provide additional renal functional information. The changed SI indicating the changing of renal blood flow and renal tubule’s concentration and dilution function. Via integrate SI received from every region of kidney in different of time, we can evaluate renal configuration and function in patients with obstructive kidney in dynamic enhanced MRI. Therefore, the purposes of this study is to evaluate Gd-DTPA enhanced MRI could be used to evaluate the individual renal function of excretion, concentration and dilution as well as ureteral obstruction in human with congenital hydronephrosis. Methods1. Patients group Eight patients including 2 adults and 6 childs (8 male, aged from 4 to 57, averaged 23 year-old) with obstructive hydronephrosis, which had already been diagnosed by ultrasonography and CT were included in this study. On the other hand, 7 unilateral hydronephrotic kidneys were been evaluated as patient’s team in 7 childs.2. Control group Eight healthy persons (7 male and 1 female, aged from 22 to 34, averaged 28.5 year-old) with normal kidneys (both sides, 16 kidneys) were included in this study. For another, the contra-side fine kidney as comparison and contrast results in 7 childs.3. Gd-DTPA enhanced MRI evaluation. The objectives were evaluated by Gd-DTPA enhanced MRI by using Siemens VB33D MRI. Non-ion paramagnetismcontrast medium (Omniscan,Gd-DTPA) was administered (0.2ml/kg body weight) intravously within 1 minute through foot vein. The patients were placed in a resupine position during the examination, body’s loop, coronary TI weighted image, The index used in this study is TR-400ms, TE-15ms, layer thickness 5-10mm, collect 13 layer, matrix 256X256, field of view(FOV) is 350- 450mm, Acq 2 , and may scan axis in necessary. The rectangular 0.25 to 0.40 cm2 ROI (region of interesting) were selected in cortex , medulla -, pelvis of the kidney and its SI was collected at pre-contrast and post-contrast image (lmin, 3mim, 5min, 10min, 15min, 30min, 45min, 60min). RSI (relative signal intensity) was calculated by using the formula RSI = (SI post Gd-DT更多还原