低场强MR泌尿系水成像对尿路梗阻性疾病的诊断价值

目的:评价低场强磁共振泌尿系水成像(MRU)对尿路梗阻性疾病的诊断价值。方法:对60例尿路梗阻性疾病患者行MRU及常规MR检查,并与B超I、VU及CT检查结果进行比较。其中输尿管癌12例,输尿管结石19例,输尿管炎性狭窄9例,肾盂输尿管连接部梗阻4例,输尿管先天畸形6例,盆腔肿瘤外压性输尿管狭窄9例,神经源性膀胱1例。结果:MRU能清晰显示尿路梗阻部位,定位诊断符合率100%,结合常规MR定性诊断符合率86.7%,优于B超、IVU及CT检查。结论:MRU结合常规MR对尿路梗阻性疾病具有较高的诊断价值,对儿童、老年人、妊娠妇女及IVU禁忌者可作为首选方法。     

尿路梗阻性病变的MRU应用

目的 探讨磁共振尿路造影(MRU)技术对尿路梗阻性病变的诊断价值。资料与方法 对46例经B超发现尿路扩张患者采用重T2WI单次激发快速自旋回波(SSFSE)序列行MRU检查，其中41例行静脉肾盂造影(IVP)。结果 46例尿路梗阻性病变包括：良性狭窄19例，先天性异常10例，输尿管结核5例，输尿管癌3例，外在性病变4例，输尿管结石4例，膀胱病变1例。MRU均清楚显示尿路影像，能确定有无梗阻，展示梗阻端的形态和特征，对梗阻水平的定位及梗阻原因的定性均有较高的准确性，明显优于IVP检查。结论 MRU是安全、有效的非侵袭性影像检查方法，特别适用于IVP禁忌症和肾功能丧失者。可多方位、多角度成像，结合常规T1WI、T2WI可获得可疑部位的大量信息，以达到明确诊断目的。     

静脉尿路造影术与MR水成像技术在泌尿系统疾病检查中的对比分析

目的:评价静脉尿路造影技术(IVU)与低场强磁共振泌尿系水成像技术(MRU)在泌尿系统疾病检查 中的应用价值。方法:对20例(正常5例,输尿管结石8例,输尿管移行细胞癌1例,输尿管中下段狭窄、扭曲2例, 肾囊肿2例,肾透明细胞癌2例)泌尿系统疾病患者,均行IVU与MRU检查,并进行对比分析。结果:IVU和 MRU检查均能清晰显示输尿管的梗阻部位,定位正确率100%,而定性正确率MRU高于IVU,且对输尿管梗阻的 病变显示较佳,但MRU不能直接观察肾脏的分泌功能。结论:泌尿系统疾病患者应首选IVU检查,以观察其功能 和形态,而对输尿管有梗阻或肾脏有占位性病变的患者应选用MRU,对儿童及不能耐受IVU检查的患者MRU也 可作为首选。     

IVU、SCTU及MRU对梗阻性尿路疾病诊断能力比较

目的比较静脉肾盂造影(IVU)、多层螺旋CT尿路造影(SCTU)及磁共振泌尿系水成像(MRU)对梗阻性尿路疾病的诊断能力,为临床选择合理检查方案提供理论依据。方法对62例经手术病理或经临床治疗随访证实的梗阻性尿路疾病患者影像资料进行回顾性分析,本组病例均行IVU检查,25例患者行SCTU检查,49例患者行MRU检查,12例患者同时行上述3种方法检查。结果 8例肾盂-输尿管移行部狭窄,IVU显示2例,7例包括IVU未显示病例MRU可清晰显示,1例CTU显示不清,不能明确诊断;19例输尿管结石病例,IVU显示9例,10例IVU未显示梗阻原因患者行CTU检查均清晰显示,13例行MRU检查,7例显示;15例输尿管肿瘤,7例行CTU检查,12例行MRU检查均显示清晰;11例输尿管外源性压迫或侵犯病例,IVU表现为肾积水,3例行CTU检查,10例行MRU检查均可清晰显示;9例输尿管炎性病变,IVU表现为肾积水,4例行CTU检查,2例显示清晰,2例与肿瘤不易鉴别,7例行MRU检查,均显示清晰。结论 IVU在梗阻性尿路疾病中主要用来筛查,当怀疑梗阻原因是结石引起时,应首选CTU检查,当怀疑梗阻原因是先天狭窄或肿瘤性病变时应首选MRU。     

MRI in patients with chronic obstructive uropathy and compromised renal function: a sole method for morphological and functional assessment

The aim of this study was to assess the role of MRI as a single modality for anatomical and functional evaluation of obstructed kidneys in patients with compromised renal function. The study included 96 adults with unilateral or bilateral chronic obstructive hydronephrosis and compromised renal function (serum creatinine >or=1.8 mg dl(-1)). Patients were subjected to gadolinium-enhanced MRI (Gd-MRI), which determined the anatomy of both renoureteral units, as well as their function, through selective calculation of the glomerular filtration rate (GFR) of each kidney. All patients underwent a technetium-99m diethylenetriamine-pentaacetic acid renal scan. Moreover, a correlation was made between the GFR determined by Gd-MRI and the isotope GFR. The study comprised 59 males and 37 females. A comprehensive MRI study detected the cause of obstruction in all kidneys with non-calcular obstruction (sensitivity of 100%) and in 21 kidneys with calcular obstruction (sensitivity of 70%). The overall sensitivity of MRI combined with plain X-ray of the abdomen and ultrasound in the detection of various causes of obstruction was 97%. A comparison between the isotope GFR of the obstructed kidneys and the corresponding magnetic resonance urography (MRU) GFR showed perfect correlation. In conclusion, combined static and dynamic MRU is a promising technique that allows anatomical and functional evaluation of obstructed kidneys in patients with impaired renal function but, owing to the possible risk of nephrogenic systemic fibrosis in patients with a GFR <30 ml min(-1), the lowest possible dose of the most stable Gd-macrocyclic chelates should be used if a functional MRI study is required.     

Renal colic: diagnosis and outcome.

To assess whether ultrasonography (US) with or without plain abdominal radiography (kidney, ureter, bladder [KUB] radiography) can replace intravenous urography (IVU) in detection of acute urinary tract obstruction, 101 consecutive patients with renal colic were evaluated with US followed immediately by IVU. Receiver operating characteristic (ROC) curves for US diagnosis of acute urinary tract obstruction yielded sensitivities of 91% and 92% for two reviewers at a specificity of 90%. There was no statistically significant difference between US and IVU results. When US was combined with KUB radiography, ROC curves yielded sensitivities of 94% and 97% for two reviewers at a specificity of 90%.KUB radiography alone was of limited diagnostic value. For US alone, no false-positive results occurred, and the false-negative results (n = 9 and n = 6 for two reviewers) were encountered in cases of grade 1 hydronephrosis and nondilated obstructive uropathy. The authors conclude that US combined with KUB radiography can replace IVU in initial evaluation and follow-up of the great majority of patients with renal colic.     

影像学检查对结石所致上尿路梗阻的诊断价值

目的 评价数字化X线摄影尿路造影[静脉尿路造影(IVU)、逆行尿路造影(RU)和经皮顺行尿路造影(PAu)]、螺旋CT(SCT)、磁共振成像(MRI MRU)对上尿路结石致梗阻的诊断价值方法62例经手术与病理证实的上尿路结石患者均经IVU，其中，26例又经RU，1例经PAU，23例经SCT，以及15例经MRI MRU检查。对不同检查方法的诊断准确率进行了比较。结果 尿路造影对七尿路结石所致梗阻定位、定性及梗阻与扩张程度的诊断准确率分别为98．4％，96．8％，100％；SCT分别为95．7％，100％，95．7％；；MRI MRU分别为86．7％，60％，93．3％。结论 在上尿路结石致梗阻的诊断中，尿路造影和SCT应作为主要检查手段，而MRI MRU可作为一种补充检查。     

先天性输尿管狭窄的影像学诊断(附31例分析)

目的：探讨超声检查(US)、静脉尿路造影(IVU)、CT和磁共振尿路成像(MRU)对先天性输尿管狭窄的诊断价值。方法：回顾性分析经手术病理证实的31例先天性输尿管狭窄的US、IVU、CT资料，其中4例行MRU检查。结果：US、IVU、CT和MRU对先天性输尿管狭窄定位诊断的总符合率分别为67．74％、87．10％、96．77％、100％，对病因定性诊断的总符合率分别为48．39％、77．42％、93．55％、50％。结论：CT、IVU对病因的定性诊断符合率较高，但四种影像学检查方法又各具优势和特点，应根据具体情况和临床需要进行选择，两种或两种以上影像学检查方法的联合应用，更能提高先天性输尿管狭窄的诊断符合率。     

磁共振成像对输尿管梗阻诊断的价值

目的目的探讨磁共振成像(MRU)在输尿管梗阻性疾病诊断中的价值。方法对44例(其中输尿管肿瘤23例,输尿管结石8例,输尿管结核及炎性狭窄5例,输尿管息肉3例,巨输尿管症5例)输尿管梗阻病人进行了MRU检查,并与B超、CT、静脉尿路造影(IVU)、输尿管逆行造影结果进行比较。结果MRU能清楚显示输尿管梗阻的部位,对输尿管梗阻的定位诊断率为100%,定性诊断率为86%。结论MRU对输尿管梗阻的诊断率高,无创且不受肾功能影响,并发症少,是对输尿管梗阻病变的最佳显示方法。     

螺旋CT尿路成像在小儿上尿路疾病诊断中的价值

目的 比较螺旋CTN水路成像（CTU）与静脉尿路造影（IVU），磁共振尿路成像（RU）在小儿上尿路疾病检查中的应用，探讨CTU对各种上尿路外科疾病的诊断价值。方法 62例疑上尿路病变儿童均做了CTU检查，31例同时行IVU检查，13例同时行MRU检查作为对照。对上尿路各部位的显影清晰度进行了评分，比较3种检查方法对上尿路各段的显示能力。按病种分类，评价CTU对儿童各种上尿路外科疾病的诊断价值，并与IVU，MRU比较。结果 在尿路形态正常组，CTU和IVU对上尿路各段的显影统计学上差异无显著性意义，且均好于MRU（P＜0．01）。在异常组，CTU对肾盏，肾盂的显示优于IVU和MRU（P＜0．01）；上段输尿管的显影，三者间统计学上差异无显著性意义；中，下段输尿管的显示，CTU，MRU均高于IVU，且统计学上差异有显著性意义（P＜0．01）。CTU对重复肾输尿管畸形，肾发育不良的诊断符合率均为100％。高于IVU和RU;峄上尿路积水的诊断符合率，CTU，MRU均为100％，高于IVU（62．5％）。结论 CTU为诊断小儿上尿路外科疾病提供了确切依据，解决了诊断中的难题，提高了诊断率。如疑有肾发育不良，重复肾输尿管畸，肾输尿管重度损伤等上尿路外科疾病，可首选CTU检查。     

不同影像学方法诊断尿路病变的临床应用分析

目的:探讨KUB平片加静脉尿路造影(IVU)、CTU和MRU对尿路病变的临床诊断价值。方法:对34例经临床和病理证实的尿路病变患者的KUB加IVU、CTU和MRU检查的影像资料进行回顾性比较分析。将各种影像学方法所得图像诊断价值分为3级:0级,不能进行定位定性分析;1级,可定位分析不能定性分析;2级,能进行定位定性分析。比较各种影像检查的临床诊断价值。结果:各种尿路病变CTU的诊断价值明显高于KUB加IVU和MRU(P<0.05)。结论:对于尿路病变CTU较KUB加IVU、MRU具有更高的临床诊断价值。CTU可作为尿路病变的首选检查方法。     

MR urography of obstructive uropathy: diagnostic value of the method in selected clinical groups

The aim of the study was to evaluate the role of MR urography (MRU) in the diagnosis of obstructive uropathy in selected groups of patients. The groups involved following pathologies: calculi; strictures of ureteropelvic junction (UPJ); benign and malignancy-induced ureterostenosis. Sixty patients with clinical diagnosis of obstructive uropathy were subjected to static fluid MRU (sMRU) with the use of 3D turbo spin echo (TSE) sequence in a 0.5-T magnet. The examination was completed with conventional MR sequences and in 12 cases additionally with sequences after the administration of Gd-DTPA and excretory MRU. The results were compared with intravenous urography (IVU), CT, US, clinical and histopathological data. The degree of the urinary tract dilatation as well as the level and type of obstruction were estimated. In patients with urolithiasis sMRU correctly depicted the degree of ureterohydronephrosis in 85%, in cases of UPJ stenosis and malignancy-induced ureterostenosis in 100% and in the group of benign ureterostenosis in 91% of patients. Determination of obstruction level in patients with stones was adequate in 92% and in cases of non-calculous ureteral strictures in 100% of patients. The sMRU sequence alone could not specify the nature of obstruction except 1 case of bladder carcinoma. Filling defects in ureters visible on MR urograms were verified with IVU or CT to exclude intrinsic tumours. Completed with conventional MR sequences sMRU enabled the depiction of solid mass or infiltration in 83% cases of malignancy-induced ureterostenosis, and in the remaining groups of patients neoplastic process was excluded in 91%. In conjunction with excretory MRU and conventional MR images sMRU appears to be a highly useful technique in assessment of obstructive uropathy, especially that of non-calculous origin. Among different clinical applications MRU is superior in the evaluation of dilated urinary tract in altered anatomical conditions (e.g. in patients with ileal neobladder). Electronic Publication     

Pediatric magnetic resonance urography

Magnetic resonance urography (MRU) is a powerful clinical tool that fuses anatomic information with functional data in a single test without the use of ionizing radiation. This article provides an overview of the technical aspects, as well as common clinical applications with an emphasis on the evaluation of hydronephrosis. A fluid challenge is an essential part of our MRU protocol and enables the definition of compensated or decompensated kidneys within the spectrum of hydronephrosis. This classification may have prognostic implications when surgery is being considered. In addition, underlying uropathy can be identified on the anatomical scans and renal scarring can be seen on both the anatomical and dynamic scans. MRU can identify and categorize dysmorphic kidneys in vivo and may provide insight into congenital abnormalities seen in conjunction with vesicoureteric reflux. MRU is still in its infancy and as the technique develops and becomes widely available, it seems likely that it will supplant renal scintigraphy in the evaluation of renal tract disorders in children.     

磁共振尿路造影在小儿泌尿系梗阻诊断中的价值

目的 探讨磁共振尿路造影(MRU)技术在小儿泌尿系梗阻诊断中的价值. 方法 65例上尿路梗阻患儿行静脉肾盂造影(IVP)、B超及MRU检查,MRU检查应用快速自旋回波重T_2WI序列.对照MRU与手术结果,比较MRU与IVP、BUS在上尿路梗阻诊断中的价值. 结果 MRU诊断肾盂输尿管连接部狭窄36例,重复肾3例(其中误诊1例),原发性巨输尿管症9例,输尿管膀胱入口狭窄4例,输尿管末端囊肿3例,孤立肾2例,肾结石5例,神经性膀胱2例,先天性肾发育不良1例.MRU对上尿路梗阻的诊断正确率为98.5%(64/65),优于IVP及B超(P＜0.05). 结论 MRU是诊断小儿上尿路梗阻的可靠方法.     

肾盂输尿管重复畸形的影像学评价

目的:分析肾盂输尿管重复畸形的影像学表现,评价各种影像学检查方法的诊断价值。方法:回顾分析13例经手术病理证实肾盂输尿管重复畸形的影像学资料(其中1例为双侧),13例均行静脉肾盂造影(IVU)和MRI平扫及磁共振水成像(MRU),其中4例行逆行造影,5例行CT扫描。结果:13例共14只肾盂输尿管重复MRI均能诊断,仅其中2例输尿管无积水扩张者未显示重复输尿管之汇合处,诊断准确率84.6%(11/13);13例IVU明确显示4例重复畸形,2例延迟显影才能诊断,6例肾盂输尿管重复未显影未能明确诊断,1例双侧重复畸形仅显示其中1侧,诊断符合率46.2%(6/13);4例逆行造影显示2例,1例输尿管下端肿瘤梗阻,另1例完全重复输尿管异位开口均插管失败,成功率50%(2/4);5例CT明确诊断4例,1例上段肾盂囊状扩张无肾盏误诊为囊肿,诊断符合率80%(4/5)。结论:肾盂输尿管重复畸形类型多样,依有无并发症而病理和影像不一,各种影像学检查方法各有其利弊,肾功能不良或伴输尿管异位开口者以CT和MRI结合MRU较适合。     

磁共振尿路成像临床应用

目的 探讨磁共振尿路成像(MRU)的临床应用价值。方法 利用PHILIPS T5-NT 0.5T超导型MR扫描机,采用快速自旋回波(TSE)序列重T_2加权技术,对52例患者作MR尿路成像,行最大信号强度投影(MIP)处理,所有患者均先行常规MR扫描。结果 52例中,尿路梗阻扩张26例,其中:肾盂-输尿管交界段狭窄7例,输尿管癌4例,输尿管结石6例,输尿管炎性狭窄4例,输尿管外压1例,膀胱癌2例,神经源性膀胱2例。MRU显示尿路梗阻扩张正确率达100％,对梗阻定性诊断有3例错误。无尿路梗阻17例,其中肾癌3例,肾盂癌2例,肾血管平滑肌脂肪瘤1例,肾囊肿9例,马蹄肾1例,一侧肾缺如1例,均由MRI和MRU相结合确诊。另有9例患者呈现不同程度肾盂积水,未见尿路梗阻征象,其中:6例结合临床诊断为肾盂肾炎。52例中,部分病例与B超、IVU、CT扫描结果进行了比较。结论 MRU为一有效安全无创的影像检查技术,特别适用于肾功能不良和有IVU禁忌症者,对确定尿路梗阻扩张,梗阻的定位、定性有重要的应用价值。MRU和MRI相结合能对泌尿系统疾病的诊断提供更为完整的诊断依据。但在实践中,应依据患者具体情况合理选用MRU检查。     

磁共振泌尿系造影对尿路梗阻性病变的诊断价值

目的 评估ＭＲ泌尿系造影对尿路梗阻性病变的诊断价值。方法 ３１０例用重Ｔ２ＷＩ快速自旋回波（ＦＳＥ）序列作ＭＲ泌尿系造影,采集资源影后作最大信号强度投影（ＭＩＰ）处理,发现１５７例为梗阻性尿路扩张。结果 １５７例梗阻性尿路扩张包括：输尿管癌２０例,输尿管结石３１例,输尿管良性狭窄３３例,先天性狭窄４８例,外在性病变致梗阻１０例,膀胱病变致梗阻１５例,ＭＲ泌尿系造影均清楚显示尿路影像,能确定有无梗阻     

Statisch-dynamische MR-Urographie Vergleich mit Ausscheidungsurographie und Szintigraphie bei experimentell induzierter Harntransportstörung (HTS)

Purpose. To assess the diagnostic value of combined static-dynamic MR urography (MRU) for the functional-morphological evaluation of experimentally induced urinary tract obstruction. Methods: Static-dynamic MRU – combination study with a respiratory-triggered 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA and furosemide – was obtained in comparison with ^99mTc-MAG3 diuretic renal scintigraphy (DRS), excretory urography (EU) and ultrasound (US) in 29 healthy piglets and in 20 piglets with surgically induced ureteric stenosis (total of 50 postoperative examination blocks). Results: MRU allowed complete depiction of the urinary tract in all controls, in operated piglets the stenosis was always correctly identified. Quality of MRU was superior to EU in 36 of 43 comparative studies. Calculation of single kidney function from parenchymal renograms, and assessment of urinary excretion from whole-kidney renograms resulted in a highly significant agreement of MRU with DRS. Conclusion: Static-dynamic MR urography allows excellent depiction of experimentally induced urinary tract obstruction, and reliable assessment of individual renal function and urinary excretion. Two advantages of the method stand out, it does not require radiation and it permits a functional-morphological correlation.     

Imaging in ureteral complications of renal transplantation: value of static fluid MR urography

Ureteral obstruction is an infrequent complication after renal transplantation that may cause rapid loss of transplant function. We tested static fluid MR urography for determining the cause of graft hydronephrosis. Magnetic resonance urography was performed in nine transplants with dilated collecting systems on ultrasound. A heavily T2-weighted 3D turbo spin-echo sequence on a 1.5-T scanner was used and maximum intensity projections were obtained. The patients also underwent excretory urography (n = 1), renal scintigraphy (n = 1), antegrade pyelography (n = 3), voiding cystourethrography (n = 4), and non-enhanced CT (n = 2). Six patients had pathologic conditions including ureteral stricture, compression by lymphoceles, implantation stenosis, vesicoureteral reflux, and late-occurring transitional cell carcinoma at the implantation site. Static MRU was able to diagnose or exclude a dilation of the graft collecting system. It visualized the course of the ureters and localized the obstruction site in four of five obstructed transplants. In one case the ureter was obscured by lymphoceles, which were demonstrated by hydrographic MRU as well. The definite cause for obstruction was provided in only 2 of 5 cases. Dilation due to vesicoureteral reflux could not be differentiated. The current multimodality approach to renal transplant imaging already provides comprehensive assessment of graft hydronephrosis. Static MRU may be useful in some cases since complications associated with intravenous iodinated contrast or antegrade pyelography can be avoided. Its main drawback, the lack of functional information, may be overcome by combining it with contrast-enhanced MRU. Received: 18 February 1999; Revised: 23 July 1999; Accepted: 18 November 1999     

Magnetic resonance urography: initial experience of a low-dose Gd-DTPA-enhanced technique

Contrast-enhanced magnetic resonance urography (MRU) is a promising tool in the evaluation of the renal collecting system, but it can be limited by T2^* effects resulting from hyperconcentrated gadolinium chelates. The aim of this study was to evaluate a low-dose dimeglumine gadopentetate (Gd-DTPA) MRU technique consisting of a dynamic fast low-angle-shot (FLASH) 2D sequence and a static fast imaging in steady state precession (FISP) 3D sequence for depicting the kidneys and urinary tract. The Gd-DTPA dose (0.01 mmol/kg) was established experimentally in a healthy volunteer study. Ninety-one patients presenting with various renal disorders were examined with a low-dose Gd-DTPA MRU and a T2-weighted turbo spin echo (TSE) MRU technique on a 1.5-T system. Image quality and diagnostic value were considered at least satisfactory in 98.9 % of the FLASH 2D studies, 83.5 % of the FISP 3D studies and 78.5 % of the TSE T2-weighted studies. Typical enhancement patterns were established for the renal cell carcinoma and transitional cell carcinoma. The major limitations were motion artefacts and insufficient hydration of the patients. Low-dose Gd-DTPA MRU appears to be a useful technique in the evaluation of the kidneys and urinary tract, especially in cases of renal tumours. Received: 26 February 1998; Revised: 25 January 1999; Accepted: 14 June 1999