Radiology of urinary undiversion

Many patients with urinary diversions are now considered candidates for “undiversion”. Radiographic evaluation prior to undiversion of the urinary tract includes cystography to determine bladder capacity and sensation, urinary continence, and the presence of reflux. Urography, loopography, and/or ureterography (antegrade and/or retrograde) are necessary to completely visualize the remaining urinary structures. Surgical techniques involved in the reconstruction are briefly discussed to facilitate an understanding of the often unusual radiographic appearance of the undiverted urinary tract. Stentograms and cystography are recommended for early postoperative evaluation to exclude urinary leakage or significant obstruction. Percutaneous ureteral perfusion studies are often useful in the long-term follow-up of these patients.     

Urinary tract infection in infants and children evaluated by ultrasound

Fifty-nine pediatric patients with urinary tract infection (UTI) underwent renal ultrasonography, excretory urography, and voiding cystourethrography. The imaging procedures were analyzed retrospectively to determine their relative effectiveness in detecting abnormalities that might predispose the patient to UTI. Voiding cystourethrography provided valuable information, particularly the presence or absence of vesicoureteral reflux, that could not be obtained from the other procedures. Excretory urography was less specific than ultrasonography in the majority of patients, with the exception of those who had renal scarring. The authors recommended ultrasonography as the initial imaging procedure in the evaluation of children with UTI. When the sonogram is normal, excretory urography is not considered necessary, but voiding cystourethrography is thought to be essential. If sonography is abnormal, excretory urography and/or other follow-up studies are indicated.     

Radiographic evaluation of children with urinary tract infections

Any child with urinary tract infection needs a radiologic work-up to determine his or her potential risk for sustaining renal damage. VCUG, either fluoroscopic or isotopic, should always be performed. If the infection responds to treatment and the VCUG is normal, ultrasonography should be performed. However, when the VCUG demonstrates reflux, radionuclide scan or, less preferably, excretory urography is indicated to assess renal parenchymal damage and function. When a urinary tract infection does not respond to treatment, ultrasonography or CT scan should be obtained to check for renal or perirenal abscess. If the findings are normal, medical treatment to control the infection is indicated. Further evaluation of the urinary tract may be temporarily delayed. In an infant with urinary tract infection and sepsis, renal ultrasonography is indicated. If the sonogram is normal, VCUG can be delayed until the infant responds to medical treatment. If ultrasonography is abnormal, VCUG and radionuclide scan such as 99mtechnetium DTPA with furosemide to evaluate gross morphology and function should be obtained. Complicated medical problems, such as urinary tract infection in combination with a history of intravenous drug abuse or with findings of fever and a mass, deserve immediate evaluation with ultrasonography or CT scan. A patient with fever of unknown origin and normal urine culture should have a radionuclide scan using gallium67 citrate or indium111-tagged leukocytes, both of which can demonstrate an extrarenal or unsuspected intrarenal site of infection. A variety of imaging modalities are available today for investigating urinary tract infections in the pediatric patient. Used intelligently, singly or in combination, these examinations provide information for the clinical evaluation as well as short-and long-term management of infections, their causes and complication, and their effect on renal function.     

CT of trauma to the abnormal kidney

Traumatic injuries to already abnormal kidneys are difficult to assess by excretory urography and clinical evaluation. Bleeding and urinary extravasation may accompany minor trauma; conversely, underlying tumors, perirenal hemorrhage, and extravasation may be missed on urography. Computed tomography (CT) was performed in eight cases including three neoplasms, one adult polycystic disease, one simple renal cyst, two hydronephrotic kidneys, and one horseshoe kidney. CT provided specific and clinically useful information in each case that was not apparent on excretory urography.     

CT尿路造影对非结石性尿路梗阻疾病的诊断作用

目的评价CT尿路造影(CTU)对非结石性尿路梗阻疾病的诊断作用。方法40例非结石性尿路梗阻病例给予实质期、分泌期增强螺旋扫描。分泌期数据经第2次重建后在工作站以三维方式获得CTU影像。结果40例中，24例良性梗阻呈轻度或重度积水。18例先天畸形CTU呈现各自特征；4例输尿管炎表现为鸟嘴样狭窄，2例前列腺增生可见膀胱后壁压迹。16例肿瘤患者梗阻端呈截断或锥状狭窄伴局部软组织影，12例尿路中度积水，4例重度积水。其中4例呈双侧积水。对6例一侧无分泌功能者，可采用最小强度投影等予以显示，并与对侧最大强度投影像等整合。结论CTU对非结石性尿路梗阻疾病的诊断具有良好的效果。     

Efficacy of the excretory urogram in the staging of gynecologic malignancies

It is common for patients suspected of having a gynecologic malignancy to be referred for excretory urography as part of their preoperative staging evaluation. This study investigates the efficacy of this practice using prospective and experimental retrospective interpretations of 88 urograms obtained for this clinical indication. The results indicate that excretory urography reliably depicts the ureters in most cases. However, the urogram is quite insensitive (sensitivity, 7%-33% among the interpretation settings) in demonstrating the extension of malignancy; specificity for this purpose was 79%-97%. The excretory urogram is useful for locating the position of the ureters and demonstrating the presence of obstruction or unsuspected urinary tract abnormalities. Nonetheless, this information also may be obtained by computed tomography, which can more accurately assess the primary mass and indicate the presence of malignant extension.     

CT urography

With the advent of multi-detector row CT scanners, evaluation of the urothelium of the entire urinary tract with high-resolution thin sections during a single breath-hold has become a reality. Multidetector CT urography (MDCTU) is a single examination that allows evaluation of potential urinary tract calculi, renal parenchymal masses, and both benign and malignant urothelial lesions. Initial results with this new technique are encouraging. Current investigations of MDCTU focus on methods to improve opacification and distension of the upper urinary tract-the collecting systems, pelvis, and ureters. The role of abdominal compression, infusion of saline and/or furosemide, and optimal time delay of excretory phase imaging is being explored. Upper tract urothelial malignancies, including small lesions less the 5 mm in diameter, can be detected with high sensitivity. Methods to reduce radiation exposure are being explored, including split-bolus contrast injection techniques that combine nephrographic and excretory phases into a single phase. It is likely that in the near future, radiological evaluation of significant unexplained hematuria or of known or prior urothelial malignancy will consist of a single examination--MDCTU.     

Excretory urography and computed tomography in the initial evaluation of patients with cervical cancer: are both examinations necessary?

One hundred ten patients with carcinoma of the cervix were studied to determine if both excretory urography and computed tomography are needed for routine evaluation. Computed tomography gave more information in 25 patients and the excretory urogram was more informative in 10 patients. Thirty-five hydroureters were detected by computed tomography, whereas excretory urography identified 21. The hydroureter in its entirety was seen more often using computed tomography, and the site of obstruction was identified in 29 of 35 cases. The superiority of computed tomography was particularly evident in patients with stage IIB or more advanced lesions. In stage I-IIA lesions, both techniques yielded the same information about the urinary tract. It was concluded that routine use of both examinations is not indicated. Excretory urography is currently sufficient in evaluation of stage I or IIA lesions, while computed tomography obviates excretory urography in patients with advanced cervical cancer (IIB-IVB).     

CT urography

With the advent of multi-detector row CT scanners, evaluation of the urothelium of the entire urinary tract with high-resolution thin sections during a single breath-hold has become a reality. Multidetector CT urography (MDCTU) is a single examination that allows evaluation of potential urinary tract calculi, renal parenchymal masses, and both benign and malignant urothelial lesions. Initial results with this new technique are encouraging. Current investigations of MDCTU focus on methods to improve opacification and distension of the upper urinary tract-the collecting systems, pelvis, and ureters. The role of abdominal compression, infusion of saline and/or furosemide, and optimal time delay of excretory phase imaging is being explored. Upper tract urothelial malignancies, including small lesions less the 5 mm in diameter, can be detected with high sensitivity. Methods to reduce radiation exposure are being explored, including split-bolus contrast injection techniques that combine nephrographic and excretory phases into a single phase. It is likely that in the near future, radiological evaluation of significant unexplained hematuria or of known or prior urothelial malignancy will consist of a single examination—MDCTU.     

Spontaneous rupture of bladder diverticulum after postoperative radiotherapy for carcinoma of the uterine cervix: a case report

We present a case of spontaneous rupture of bladder diverticulum three years after postoperative whole pelvic irradiation (50.4 Gy) for carcinoma of the uterine cervix. The patient had suffered from a neurogenic bladder after hysterectomy, but excretory urography revealed no abnormalities. Bladder diverticulum was found two years later. Spontaneous rupture of the urinary bladder is one of the late complications associated with radiotherapy, although it is very rare. Postoperative neurogenic bladder may also be associated with rupture. We should be aware of this rare complication in patients who receive pelvic irradiation.     

Urography and voiding cystourethrography: findings in girls with urinary tract infection

The voiding cystourethrogram and excretory urogram have been considered essential parts of the evaluation of girls with urinary tract infections. To evaluate the usefulness of these procedures, 523 examinations in girls with urinary tract infections were reviewed retrospectively. The major finding on voiding cystourethrograms was vesicoureteral reflux, occurring in 36% of the children. Of the total group, 8% had excretory urographic evidence of parenchymal scarring. Higher grades of reflux were associated with an increase in parenchymal scarring. All urethras were normal, and only one paraureteral diverticulum was identified. Bladder emptying was incomplete in 46% of the patients. Ovarian radiation doses were measured with "low-dose" and standard systems. On the basis of this study, traditional approaches to the standard workup are questioned.     

Voiding cystourethrography: the initial radiologic study in children with urinary tract infection

The order in which children with urinary tract infection should undergo voiding cystourethrography (VCUG), excretory urography (EU), and/or renal ultrasonography (US) is not standardized. To determine a logical sequence of study, we performed VCUG and then either US or EU on 389 consecutive children with urinary tract infections. Thirty-seven percent (133/358) of the children were found to have reflux; of these, 22.5% (30/133) had an abnormal excretory urogram. No correlation was found between either the age of the child and the degree of reflux or the age of the child and the percentage of children with abnormal excretory urograms. Since normal EU or US results do not exclude significant reflux, VCUG is recommended as the preferred initial screening examination in children with urinary tract infection.     

排泄性磁共振尿路成像在泌尿系疾病诊断中的价值

目的:探讨对比增强磁共振尿路成像(排泄性MRU)在诊断泌尿系疾病方面的价值.方法:选择经手术病理和影像学检查证实的泌尿系结石20例、肾盂旁囊肿6例、肾盏憩室1例、膀胱憩室3例和输尿管移行细胞癌4例,均先行磁共振尿路成像(常规MRU),然后增强扫描后延迟至5、10和20 min行排泄性MRU,显示不良者4 h后再扫描一次.将两者源图像分别进行最大强度投影(MIP)重组,并分别独立诊断,对两者结果进行对比分析.结果:排泄性MRU尿路显示清楚 5 min 5例,10 min 25例,4 h 4例.两者定位诊断符合率均为100%.排泄性MRU均能作出准确定性诊断,常规MRU准确定性诊断分别为泌尿系结石17例(17/20)、肾盂旁囊肿2例(2/6)、膀胱憩室3例(3/3)、输尿管移行细胞癌2例(2/4).结论:排泄性MRU能清楚显示尿路形态变化及、排泄功能,有利于尿路疾病的诊断.     

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.     

Evaluation of pelvic masses during infusion excretory urography.

Infusion excretory urography not only clearly delineates the urinary tract structures, but provides additional information about the type of pelvic mass present. Benign uterine fibroids show contrast enhancement in a significant number of cases, whereas endometrial and cervial malignancies give no specific pattern. Cystic and mixed ovarian neoplasms show rim opacification in over 50 per cent of cases, and the presence of this rim sign points strongly to an ovarian lesion. The opacification of solid ovarian tumors cannot be differentiated from that of uterine fibroids unless other identifying features such as specific calcification or visualization of a normal uterus are present. Pelvic inflammatory disease shows no specific type of opacification. Excretory urography is part of the preoperative evaluation in most patients with pelvic mass lesions. By utilizing the infusion method, high quality excretory urograms are obtained, and, in addition, helpful information is obtained regarding the type of pelvic mass present.     

Vesicoureteral reflux in adults.

Vesicoureteral reflux was detected in 200 adults seen in a 4 year period. In group 1 (no history of urinary tract infection and negative urine cultures), all patients had abnormalities on excretory urograms that were suggestive of reflux. In patients with a history of recurrent urinary tract infection (groups 2 and 3), the excretory urograms showed an abnormality in 79 per cent of those with negative cultures and in 83 per cent of those with positive cultures. Thus, reflux should be suspected in patients with a history of recurrent urinary tract infection even if infection cannot be documented with urine culture. Urographic evidence of renal parenchymal scarring, ureteral dilatation, or mucosal striations should also suggest the possibility of vesicoureteral reflux even when the patient may have no urinary tract symptoms. Voiding cystourethrography should be performed in all adults with these findings to exclude the possibility of vesicoureteral reflux.     

多层螺旋CT在活体肾移植供体术前综合评估中的价值

目的 探讨多层螺旋CT(MSCT)在活体肾移植供体术前综合评估中的价值.方法 36名活体亲属供肾者术前均行MSCT扫描,前25名行平扫及动脉早期、动脉晚期、排泄期3期增强扫描(对比剂注射流率5 ml/s,总量100 ml,管电压120 kV),后11名行平扫(100 kV)及血管期、排泄期(100 kV)双期增强扫描(对比剂以2 ml/s流率注射40 ml,以4 ml/s流率注射60 ml),均采用排泄期的数据进行CT尿路成像(CTU).将图像与经手术证实的33名受检者术中所见对照,评价MSCT在评估供肾血管、尿路及肾实质情况的价值.对2组不同参数扫描的三维(3D)重组图像质量采用Mannwhitney U精确检验.结果 CT血管成像(CTA)对供肾动静脉主干、副肾动脉、动脉提前分叉、肾静脉主干变异、左肾静脉属支和交通支及CTU对尿路的显示与术中一致.2组三维(3D)血管重组图像质量评分分别为(4.4±1.2)和(4.2±1.3)分,CTU重组图像质量评分分别为(4.6±0.8)和(4.4±0.9)分,差异均无统计学意义(Z值分别为-0.89、-0.47,P值均＞0.05).结论 MSCT可以直观、准确地评价活体供肾者的血管、尿路及肾实质的情况,在活体供肾术前综合评估中起着重要作用.     

Sonography as a substitute for excretory urography in children with urinary tract infection

The possibility was explored of substituting renal sonography for excretory urography in children with urinary tract infection. Seventy-one patients were studied prospectively with voiding cystourethrography, sonography, and excretory urography; each examination was reviewed independently and without knowledge of the results of the others. Compared with urography the sensitivity and specificity of sonography was 100% and 51%, respectively, provided sonograms were of good technical quality. In a few instances, however, focal renal parenchymal scars were clearly seen only on urography. The findings suggest that in the absence of vesicoureteral reflux children with urinary tract infection should be studied with sonography. No further study is needed if a good-quality sonogram is within normal limits. In the presence of vesicoureteral reflux, however, or a suspicious or abnormal sonogram, excretory urography appears to be still necessary, at least at the present level of knowledge and technical expertise.     

Radiological findings of the urinary tract in hypospadias: a report of 110 cases.

One hundred and ten patients with hypospadias underwent excretory urography and micturating cysto-urethrography before surgical correction. Urographic studies revealed abnormalities in 50 patients (45%), mainly anomalies of ascent and rotation of the kidneys. None of these patients required corrective surgery. Voiding cysto-urethrography disclosed disease of the urinary tract in 65 of 110 patients (59%). Meatal stenosis was found in 38 patients and a rudimentary vagina or a prostatic utricle was revealed in 11 others. Vesico-ureteral reflux was present in 14 patients, seven of whom had meatal stenosis as well. Cystitis was found in eight and a stricture of the membraneous urethra in one patient. The voiding cysto-urethrogram is able to demonstrate functionally significant meatal stenosis, genital abnormalities and vesico-ureteral reflux. It can also serve as a useful baseline for comparison with postoperative studies. We therefore consider that it should be included in the preoperative work-up of every patient with hypospadias. Excretory urography, however, is perhaps indicated only in those with urinary tract infection, or in patients otherwise symptomatic.     

Multi-detector CT urography: effect of oral hydration and contrast medium volume on renal parenchymal enhancement and urinary tract opacification—a quantitative and qualitative analysis

Objective

To assess the effect of oral hydration and contrast-medium volume on renal enhancement and urinary tract opacification in multi-detector CT urography.

Methods

A total of 192 patients were assigned to different protocols with varying doses of contrast agent with and without oral hydration. The attenuation was measured in the renal parenchyma in the unenhanced, nephrographic and excretory phase, and in the urinary tract in excretory phase imaging, respectively. Opacification of the urinary tract was graded on volume rendered images.

Results

Oral hydration did not significantly alter renal parenchymal enhancement in both the nephrographic and the excretory phase (p?>?0.001), but significantly decreased mean attenuation of the urinary tract in the excretory phase (p?≤?0.001), and improved continuous opacification of all ureter segments (p?<?0.01). Higher volumes of contrast medium improved renal parenchymal enhancement (p?≤?0.001) and continuous opacification of the urinary tract (p?≤?0.01).

Conclusion

Oral hydration leads to lower attenuation values in the urinary tract but improves the continuous opacification of the tract. Increase in contrast medium volume leads to higher renal parenchymal enhancement as well as to an increased continuous opacification of the urinary tract. Decrease in contrast medium volume cannot be compensated for by oral hydration in terms of parenchymal enhancement.