Evaluating pediatric ureteropelvic junction obstruction:Dynamic magnetic resonance urography vs renal scintigraphy 99mtechnetium mercaptoacetyltriglycine

BACKGROUND Ureteropelvic junction obstruction(UPJO)is a common congenital urinary tract disorder in children.It can be diagnosed as early as in utero due to the presence of hydronephrosis or later in life due to symptomatic occurrence.AIM To evaluate the discrepancy between dynamic contrast-enhanced magnetic resonance urography(dMRU)and scintigraphy 99m-technetium mercaptoacetyltriglycine(MAG-3)for the functional evaluation of UPJO.METHODS Between 2016 and 2020,126 patients with UPJO underwent surgery at Robert DebréHospital.Of these,83 received a prenatal diagnosis,and 43 were diagnosed during childhood.Four of the 126 patients underwent surgery based on the clinical situation and postnatal ultrasound findings without undergoing functional imaging evaluation.Split renal function was evaluated preoperatively using scintigraphy MAG-3(n=28),dMRU(n=53),or both(n=40).In this study,we included patients who underwent surgery for UPJO and scintigraphy MAG-3+dMRU but excluded those who underwent only scintigraphy MAG-3 or dMRU.The patients were divided into groups A(<10%discrepancy)and B(>10%discrepancy).We examined the discrepancy in split renal function between the two modalities and investigated the possible risk factors.RESULTS The split renal function between the two kidneys was compared in 40 patients(28 boys and 12 girls)using scintigraphy MAG-3 and dMRU.Differential renal function,as determined using both modalities,showed a difference of<10%in 31 children and>10%in 9 children.Calculation of the relative renal function using dMRU revealed an excellent correlation coefficient with renal scintigraphy MAG-3 for both kidneys.CONCLUSION Our findings demonstrated that dMRU is equivalent to scintigraphy MAG-3 for evaluating split renal function in patients with UPJO.

Effects of Saline Administration, Abdominal Compression, and Prolongation of Acquisition Delay on Image Quality Improvement of CT Urography

Objective To retrospectively evaluate the effects of saline administration following contrast material injection, abdominal compression and two delay phase acquisition on image quality improvement of computed tomographic urography (CTU). Methods Medical records and informed consents of patients were obtained. In totally 122 patients (50 men, 72 women), two delay phase images with CTU were performed. Scans began simultaneously with a contrast bolus injection of 100 mL (300 mgI/mL) followed by a saline bolus injection of 100 mL at a rate of 5 mL/s. Two delay phase images were taken at 400 and 550 seconds for each patient. Examinations were taken by using abdominal compression or not. The distention and opacification of the urinary tract were evaluated by two interpreters together on transverse images and post-processing images. Effects of four techniques (saline administration and abdominal compression, saline administration only, compression only, and neither saline administration nor compression) and two delay phase acquisition on image quality improvement were analysed by using ANOVA and Chi-square test. Results Saline administration improved opacification (P<0.05) and increased overall image quality (P<0.01) of the intrarenal collecting system and proximal ureter. Abdominal compression (P<0.05) and delayed phase image acquisition of 550 seconds (P<0.01) all improved distention of the intrarenal collecting system and proximal ureter but did not improve opacification. No statistically significant effects on the distal ureter were found. However, there were more visualized distal ureteral segments with the longer imaging delay. Conclusion Saline administration, abdominal compression and longer imaging delays are all effective in improving image quality of 64-detector row CTU.

Magnetic Resonance Urography and X-ray Urography Findings of Congenital Megaureter

Objective To observe the imaging findings of congenital megaureter in order to enhance the understanding of this disease. Methods Image data of 5 patients with congenital megaureter and 2 misdiagnosed patients were analyzed, and image findings of congenital megaureter were summarized. Elscint Prestig 2.0T superconductive magnetic resonance urography （MRLI） with conventional sequence （spin-echo, T 1W1560 ms/16 ms; fast spin-echo, T2WI 9600 ms/96 ms） was performed. Raw data were acquired with fast spin-echo sequence from heavy T2-weighted image （9600 ms/120 ms）. Post-processing method of MRH was the maximum in- tensity projection with three-dimensional reconstruction in the workstation. Intravenous pyelography （IVP） was conducted, in which X-ray films were taken 7 minutes, 15 minutes, and 30 minutes after injecting contrast agent, except that in 2 patients the films were taken delayed at 60 and 90 minutes. X-ray retrograde pyelography was performed on 2 patients, successful in one but failed in the other. Results The dilated ureter showed hypointensity on T1-weighted images and hyperintensity on T2-weighted images in conventional MRI. The mass wall was intact, uniform in thickness, and showing hy- pointensity on Tl-weighted and T2-weighted images. The MRH images showed a retroperitoneal mass appearing as an elongated tubular cystic structure spreading from kidney to bladder. MRLI also revealed dilated calices and renal pelvis, pelviureteric obstruction, and renal duplication. The main signs of congenital megaureter in X-urography was significant dilatation of ureter, or normal renal pelvis with ureter dilatation, hydronephrosis, deformity, and displacement. Conclusions MRH with X-urography could visualize the characteristics of congenital megaureter, including the dilation of renal pelvis and ureter, calculi, urinary tract duplication, and stenosis location. The two techniques can complement each other in disease diagnosis and provide more detailed information for preoperative treatment.

Role of multi- slice CT urography over ultrasonography in patients with hematuria

Objective:Understanding the role of Multi-slice CT Urography(MSCTU)over Ultrasonography(US)in patients presenting with hematuria.Materials and Methods:Retrospective study enrolled 131 patients presenting with hematuria[microscopic hematuria(n=60)]and macroscopic hematuria(n=71)]who have undergone both MSCTU and US of urinary tract system simultaneously.Results of tests were compared with respective surgical and histopathological analysis of lesion.The cases obtained were bladder carcinoma,ureter carcinoma,renal carcinoma,urinary tract calculi and bladder inflammation.PASW-18thstatistical tool was used for obtaining statistical analysis and final interpretation of results.Results:The sensitivity and specificity of MSCTU and US for recognition of lesions presenting with macroscopic hematuria were 95.38%,83.33%and 81.54%,66.67%respectively and for those with microscopic hematuria were 96.08%,88.89%and 86.27%,77.8%respectively.The positive and negative likelihood ratios of MSCTU and US in macroscopic category were 5.73,0.055 and 2.46,0.277 respectively while for those in microscopic category were 8.65,0.044 and 3.88,0.176 respectively.In context to the sensitivity of MSCTU and US in patients presenting with macroscopic hematuriathedifferenceswere significant(McNemar's test,P=0.039)suggesting the tests are not similar whereas for those with microscopic hematuria the differences were not significant(Mc Nemar's test,P=2.68)indicatingsimilarity between these tests.Conclusion:Diagnostic efficacy of MSCTU is found to be far superior over US for patients presenting with macroscopic hematuria,thus current practice of using it as a first line modality seems to be justified.However,for those presenting with microscopic hematuria MSCTU and ultrasonography shows near to similar resultsin accordance to MSCTU,thus US alone seems sufficient to exclude significant urinary tract lesions.

Study of Role of Magnetic Resonance Urography (MRU) and Comparison with Conventional Radiology in the Diagnosis of Complex Renal Anomalies: A Tertiary Care Centre Experience

Anatomical renal anomalies are one of the most commonly occurring renal anomalies. Most of these anomalies require series of investigations for the proper diagnosis. We tried to compare the results of conventional radiological investigations with magnetic resonance urography in the diagnosis of complex renal anomalies. Materials and methods: This was a prospective study done over a period of five years from 2006 to 2011. All the patients with suspected or diagnosed presence of renal anomalies were investigated by ultrasound (USG), Intravenous urography (IVU), micturating cystourethrogram (MCU), magnetic resonance urography (MRU), retrograde urethrography, cystogenitoscopy, renal scans as per the indication in the case. Results: Total sixty three patients were studied over the period. The most common complex renal anomaly diagnosed was duplex system and conventional radiological investigations were useful in the diagnosis of less than 50% patients. Female patients outnumbered male patients in having complex renal anomalies. MRU was diagnostic in most of the patients with such anomalies and excellent mode of investigation for functional and anatomical details. Conclusion: MRU is better than conventional radiological investigations in the diagnosis of complex renal anomalies.

Comparison of Magnetic Resonance Urography (MRU) with Intravenous Pyelography (IVP) in Evaluation of Patients with Hydronephrosis on Ultrasonography Due to Pelvi-Ureteric Junction Obstruction

The objective of this study was to compare Magnetic Resonance Urography (MRU) with Intravenous Pyelography (IVP) in evaluation of patients with hydronephrosis on ultrasonography. 49 patients of hydronephrosis on USG were enrolled for the study from Jan. 2011 to Dec. 2012. All patients under went Intravenous Urography (IVU). MRU was done to determine the anatomical details and function of each renal unit. MRU was performed on a 1.5 tesla unit (Magneton Avento;Siemens, Erlangen, Germany). Static T2-weighted Magnetic Resonance Urography (MRU) was performed by using a standard fast spin echo technique. Dynamic study was performed after injecting intravenous diuretic followed by Gadolinium contrast media. Morphological results of MRU were compared with IVU. The anatomical findings were compared with operative findings. Stastical analysis was performed and data expressed as mean ± SD. MRU showed PUJ obstruction in 41 out of 45 patients (91.1%). We concluded that MRU can provide complete diagnostic evaluation of entire urinary tract in a single session and has potential to replace IVP.

Magnetic resonance urography in the diagnosis of urinary tract obstruction after renal transplantation

OBJECTIVE: To evaluate magnetic resonance urography (MRU) in the diagnosis of urinary tract obstruction after renal transplantation. METHODS: A total of 31 patients with suspected urinary tract obstruction after renal transplantation were examined, and the results were compared with those from surgery and B-ultrasound examination. RESULTS: The urinary tract after renal transplantation was clearly shown using MRU, and all patients were clearly diagnosed by MRU. Imaging results were consistent with those from surgery. CONCLUSIONS: MRU is suitable for detecting urinary tract obstruction after renal transplantation. It is a alternative method for IVP and CT in patients with renal function impairment and uremia.

Poor visualization of renal collecting system in intravenous urography as an indicator of invasive transitional cell carcinoma in the upper urinary tract

Background Transitional cell carcinoma of the upper urinary tract （UUT-TCC） accounts for 5% to 10% of all renal tumours and 5% to 6% of all urothelial tumours all over the world. In China, the proportion of UUT-TCC to all urothelial tumours may be 26%, which is higher than that in the western world. The early diagnosis of UUT-TCC is difficult and the present study elucidates the diagnostic value of poor or nonvisualization （PNV） in intravenous urography in patients with UUT-TCC and its correlations with pathological findings and clinical characteristics. Methods The data of 172 consecutive patients between January 1997 and January 2005 with UUT-TCC who underwent nephroureterectomy in our departments were selected and analyzed retrospectively. Results Of our sample, 144 cases presented with gross haematuria （83.7%） and 12 with microscopic haematuria （7.0%）. Forty-six cases （26.7%） were detectable by cytology. Filling defect identified 36 positive cases of 172 patients （20.9%）, PNV was present in the images of 105 of 172 patients （61.0%）. The detection rate by PNV （61.0%） was significantly different from that by cytology （26.7%） or by filling defect （20.9%） （P=-0.031, P=-0.001, respectively）. Univariate logistic regression analysis for PNV showed that tumour stage, grade and size were significant predictors （P=0.028; P=-0.031; P=-0.006, respectively）. Tumour stage and size were identified as independent risk factors in the multivariate logistic regression model （P=-0.042; P=-0.014）.Conclusions Except for suspected urolithiasis, urinary tuberculosis or congenital abnormalities, UUT-TCC should be considered if PNV exists in intravenous urography especially of old patients. The value of PNV is much more significant than filling defect in intravenous urography in the diagnosis of UUT-TCC. It is supposed that PNV carries more risk of higher stage and larger tumour size in UTT-TCC.

Practical value of intravenous urography combined with add-on CT in diagnosina ureteral abnormalities

Background Intravenous urography （IVU） combined with add-on CT （IVU-CT） can help to provide more diagnostic information for determining the localization and nature of ureteral abnormalities with less irradiation dose. This study aimed to determine the value of IVU-CT for diagnosis of ureteral diseases, where IVU is insufficient to determine the diagnosis. Methods Two hundred and eighty patients underwent IVU for suspected ureteral disorders, which identified a definite diagnosis in 184 cases and was insufficient for definite diagnosis in 96 cases designated as indeterminate diagnosis. Subsequently 90 patients （six patients declined CT） with indeterminate diagnosis consented to undergo immediate or delayed helical CT scan. The CT data were transferred to the workstation for post-processing, and the cost and mean effective dose for each imaging method were calculated and compared indirectly. Results Of the 90 indeterminate diagnosis cases, diagnosis was determined in 86 cases by IVU-CT with a diagnostic accordance rate of 95.6%, while 184/280 （65.7%） had diagnosis determined by IVU alone. There was a significant difference between IVU and IVU-CT in the determination of the diagnosis of ureteral diseases （X2=36.4, P 〈0.05）. The cost of IVU equals to 1/8-1/9 of that for CT urography （CTU）, and the cost of IVU-CT is as much as 1/3 of CTU. CTU results in the highest mean effective dose, approximately nine times that for IVU and three times that for IVU-CT. Conclusion IVU-CT provides valuable information for the localization and diagnosis of ureteral abnormalities and may be considered as an efficient, cost-effective and low-dose diagnostic technique in this setting.

Calyceal Diverticulum Mimicking Simple Parapelvic Cyst:a Case Report

CALYCEAL diverticulum is a cystic intrarenal cavity lined by nonsecretory transitional epithelium that communicates with the collecting system via a narrow isthmus or infundibulum. It is arare anatomic anomaly with an incidence of 0.2% to 0.6% in the patients undergoing renal imaging.1 Single imaging modality usually cannot differentiate calyceal diverticulum from other cystic renal diseases.2 Here, we report a 60-year-old male who was reliably diagnosed with calyceal diverticulum by retrograde urography combined with non-enhanced computed tomography （CT） and magnetic resonance urography （MRU）.

Multi-modality imaging review of congenital abnormalities of kidney and upper urinary tract

Congenital abnormalities of the kidney and urinary tract(CAKUT) include a wide range of abnormalities ranging from asymptomatic ectopic kidneys to life threatening renal agenesis(bilateral). Many of them are detected in the antenatal or immediate postnatal with a significant proportion identified in the adult population with varying degree of severity. CAKUT can be classified on embryological basis in to abnormalities in the renal parenchymal development, aberrant embryonic migration and abnormalities of the collecting system. Renal parenchymal abnormalities include multi cystic dysplastic kidneys, renal hypoplasia, number(agenesis or supernumerary), shape and cystic renal diseases. Aberrant embryonic migration encompasses abnormal location and fusion anomalies. Collecting system abnormalities include duplex kidneys and Pelvi ureteric junction obstruction. Ultrasonography(US) is typically the first imaging performed as it is easily available, noninvasive and radiation free used both antenatally and postnatally. Computed tomography(CT) and magnetic resonance imaging(MRI) are useful to confirm the ultrasound detected abnormality, detection of complex malformations, demonstration of collecting system and vascular anatomy and more importantly for early detection of complications like renal calculi, infection and malignancies. As CAKUT are one of the leading causes of end stage renal disease, it is important for the radiologists to be familiar with the varying imaging appearances of CAKUT on US, CT and MRI, thereby helping in prompt diagnosis and optimal management.

无压式大剂量IVU加延迟摄片在中重度肾积水梗阻部位诊断中的价值

目的探讨无压式大剂量静脉尿路造影(Intravenous urography,IVU)加延迟摄片在中重度肾积水梗阻部位诊断中的应用价值。方法从本院2011年9月—2013年9月收治的中重度肾积水患者中随机选择100例进行研究,随机分为两组,分别给予B超检查和无压式大剂量IVU加延迟摄片检查。结果利用无压式大剂量IVU加延迟摄片检查的梗阻部位诊断准确率高于B超检查,经比较差异有统计学意义(χ2=8.23,P<0.05)。结论较之B超检查,利用无压式大剂量IVU加延迟摄片检查对中、重度肾积水的患者进行诊断,可以达到较高的梗阻诊断准确率,效果确切,值得推广。

IMAGING TECHNIQUES FOR THE DIAGNOSIS OF RENAL TUMORS

In recent years.diagnostic imaging techniques,especially ultrasonography (US) and CTscanning,have been widely adopted in clinical practice,making early accurate diagnosisof renal tumors possible.A total of 452 cases of renal tumors have been admitted to theinstitute since 1951,of which 220 were seen from 1951 to 1979 and 232 in the past 9years (1980-1988).The frequency of renal parenchymal tumors was obviously higher in thelatter group,including asymptomatic renal carcinoma in 20.2% and hamartoma in 38.1%.All these were discovered on routine physical check-up by ultrasonography and/or CTscanning and would otherwise have gone undiagnosed on conventional urography.Ultra-sonography and CT can also reveal the nature and the extent of the tumor.The idea that“a renal tumor should be considered malignant unless pathologically proven otherwise”isno longer valid.However,general manifestations of renal carcinoma,such as elevatederythrocyte sedimentation rate (ESR),hypertension,malaise,anemia,fever and hypercalcemia,still deserve proper attention.We suggest that ultrasonography of both kidneys should bemandatory in routine physical check-up,as far as the urinary system is concerned,in orderto discover asymptomatic renal tumors.

Characteristics on diagnosis and treatment of renal tuberculosis

Objective To study the new characteristics on diagnosis and treatment of renal tuberculosis ( RT). Methods Eighty-seven patients with renal tuberculosis were retrospectively reviewed; their diagnosis was established by standard microbiological and histological techniques. Results Atypical RT was diagnosed by various examinations, including urinary analysis, polymerase chain reaction of tuberculosis ( PCR-TB), ultrasonography, intravenous urography ( IVU), and computerized tomography (CT). Treatment consisted of antituberculous chemotherapy in all patients, in combination with nephrectomy (62. 5 %) or enterocytoplasty (4. 6%). Conclusion The differential diagnosis of RT should be emphasized, especially for atypical RT, provided a much more specific diagnosis in clinical suspicion of RT. IVU can not be regarded as a specific examination for RT. Computerised tomography (CT) can be used for early diagnosis of RT. Surgery for TR is still ablative. 5 refs.

MRI of the Bladder in Patients Suspected of Bladder Tumors

Objective: To prospectively evaluate the use of MRI for the detecting of bladder tumors and the T- stage using T2W, T1W and diffusion-weighted images (DWI). Material and methods: Twenty-eight consecutive patients (21 men, 7 women;age range, 20 - 82 years;mean age, 62.8 years) suspected of bladder tumors underwent MRI, flexible cystoscopy and transurethral resection (TURB). The presence of bladder tumor was confirmed by histopathology in 21 patients;18 patients had pTa, one pT1 and two pT2. The images were reviewed by two uroradiologists. They assigned the presence of a bladder tumor and whether the tumor was non-muscle invasive (Ta and T1) or muscle- invasive (T2, T3 or T4). Results: Compared to the histopathological results, the accuracy for identifying a bladder tumor was 60.7% and 53.7% for reviewer A and B, respectively. The sensitivity and specificity were 66.7%/61.9% and 57.1%/42.9%. Positive predictive values were 82.6%/ 76.5%. The overall staging was correct in 47.6%/52.5%, but improved on stage-by-stage up to 50%/66.7%. The agreement between the reviewers was moderate in the detecting, staging and location of the tumor (Kappa = 0.47 - 0.57). Conclusion: A simple MRI using no contrast media, but DWI, cannot replace flexible cystoscopy in the detection of new or recurrent bladder tumors.

经皮肾镜碎石术致结肠损伤意外拔管后多处脓肿形成一例报告

经皮肾镜碎石术导致结肠损伤是一种罕见而严重的并发症,虽然近年来有一些报道,但对于在确诊结肠损伤前就拔除了肾造瘘管的处理非常棘手。攀钢集团总医院发生1例,为引起重视并加以预防,结合相关文献复习,现报告如下。

The value of three-dimensional helical computed tomography for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones

Objective: The aim of our study was to determine if there is any advantage of three-dimensional helical computed tomography (3D-HCT) over intravenous urogram (IVU) for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones. Methods: From June 2012 to January 2014, a total of 52 cases of lower pole renal stones underwent retrograde intrarenal surgery (RIRS) in our center. All patients underwent a preoperative IVU and three-dimensional helical computed tomography urography (3D-CTU) program to define the collecting system anatomy, manly concerning the following lower pole features; infundibu-lopelvic angle (IPA), infundibular length (IL), and infundibular width (IW). The examinations were performed in the same cen-ter of reference with a standardized method and with 3D-HCT Siemens Somaton Plus equipment. The measurements were per-formed by the same researcher, using a ruler and a square. Results: Based on clinical threshold difference of the anatomic factors on an IVU image to compare the difference between an IVU image and a 3D-CT image of 52 patients, the IPA was<30? when measured on intravenous pyelography (IVP) for 21 patients. We found that with the IPA of<30? measured with IVP only 19%(4/21) were correctly classified in the same size category using 3D-HCT, whereas 81%(17/21) were upgraded to 40e50? on 3D-CT. This difference was significant between IVP and 3D-HCT. Conclusions: 3D-HCT has advantages over IVU when analyzing the morphometric and the morphological features of kidney lower pole spatial anatomy for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones.