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.     

Reliability of the combination of ultrasonography-cystography in the study of urinary infection in children. Prospective study on 90 cases

The authors report a prospective study concerning 90 children with a urinary tract infection, investigated for the first time by radiological and ultrasonographic techniques. Amongst these 90 children, 50 (i.e. 55% of cases) had a normal retrograde cystography and ultrasonography. These children did not have any IVU and medical surveillance proved to be sufficient. Ten patients had a normal retrograde cystography and abnormal ultrasonography. Intravenous urography carried out in these 10 cases revealed in 8 instances an abnormality of the upper urinary tract. Finally 30 children had an abnormal retrograde cystography, with reflux in 29 cases, leading to intravenous urography which yielded a pathological result in only half of the cases studied. This series confirms the central role of retrograde cystography. When it is normal, intravenous urography may be legitimately substituted by ultrasonography.     

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.     

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.     

Urinary tract infection in children. A reappraisal of its radiologic investigation

In a prospective study, 100 children with either an acute or a previous history of urinary tract infection were investigated by intravenous urography, micturition cystourethrography, and ultrasonography. The results from the three diagnostic modalities were compared: The urinary tracts in 59 patients were normal, and revealed some abnormality in 41. Ultrasonography proved to be superior to intravenous urography in outlining renal contours and in detecting subtle cortical changes secondary to urinary tract infection (such as slight increases in cortical thickness and edema or cortical scarring). The mucosa of the renal pelvis and bladder was more easily assessed by ultrasound than by intravenous urography. Both modalities were "equally" accurate in detecting important congenital malformations of the urinary tract. Ultrasound failed to detect 24 of 28 ureters demonstrating reflux on voiding cystourethrography. We propose that carefully performed abdominal ultrasonography can replace intravenous urography in the initial investigation of urinary tract infection in children. It should be done in association with a radiographic or radionuclide voiding cystogram. Intravenous urography would then become a complementary examination for abnormal or problematic patients.     

Anomalies of the distal ureter, bladder, and urethra in children: embryologic, radiologic, and pathologic features.

Congenital anomalies of the lower urinary tract are a significant cause of morbidity in infancy. Radiologic investigation is an important source of clinical information in lower urinary tract disorders but should not inconvenience the patient, expose the patient to unnecessary radiation, or delay surgical correction. In pediatric patients with suspected underlying urologic structural anomalies, screening ultrasonography is commonly the initial diagnostic study. If dilatation of the urinary tract is confirmed, voiding cystourethrography is performed to determine the presence of vesicoureteral reflux (VUR) and other causes of upper tract dilatation. If VUR is confirmed, follow-up with nuclear cystography or echo-enhanced cystosonography may be performed. If VUR is excluded, nuclear diuresis renography is the primary test for differentiating between obstructed and nonobstructed megaureter. Intravenous urography can be used to specifically identify an area of obstruction and to determine the presence of duplex collecting systems and a ureterocele. Computed tomography and magnetic resonance (MR) imaging are unsuitable for general screening but provide superb anatomic detail and added diagnostic specificity. MR imaging is mandatory in the evaluation of associated spinal anomalies. MR urography can demonstrate ectopic extravesical ureteric insertions, thereby providing a global view of the malformation. Familiarity with anomalies of the lower urinary tract is essential for correct diagnosis and appropriate management.     

99Tcm-mercapto acetyl triglycine in paediatric renal tract disease.

The use of 99Tcm-mercapto acetyl triglycine (99Tcm-MAG3), a new hippuran substitute, has been reported widely in adults but not in children. Our experience of its use in 100 infants and children for renography and indirect micturating cystography (IMC) is reported. The average age was 5.6 years. 65 patients completed IMC studies and nine patients had 99Tcm-dimercaptosuccinic acid (99Tcm-DMSA) scans performed on the same day. The majority of patients were referred for the investigation of urinary tract infection. 32 kidneys were found to be scarred on 99Tcm-MAG3 scans, 17 kidneys and ureters refluxed on IMC and 14 kidneys were obstructed. The results of 99Tcm-MAG3 scans were compared with those of other urinary tract investigations including ultrasound, micturating cystography (MCUG), intravenous urography (IVU) and 99Tcm-DMSA scintigraphy. No kidney which was scarred had a normal 99Tcm-MAG3 scan. All significant degrees of dilatation or obstruction on IVU or ultrasound were also detected by 99Tcm-MAG3. 99Tcm-MAG3 gave more information than any other single imaging modality and we believe it represents an ideal initial screening test in the investigation of urinary tract infection in older toilet-trained children.     

The coexistence of ureteropelvic junction obstruction and reflux

Since ureteropelvic junction obstruction is the most common upper urinary tract problem in children, and vesicoureteral reflux the most common lower tract problem, it is not surprising that these entities sometimes coexist in the same child. Over a 10 year period this uncommon phenomenon has been noted 21 times (in about 2,800 children with reflux and 200 children with ureteropelvic junction obstruction). Significant ureteropelvic junction obstruction in association with mild reflux can mimic severe reflux, but the operation needed is not reimplantation but pyeloplasty. Conversely, when significant ureteropelvic junction obstruction coexists with significant reflux, both operations may be necessary, but the order in which they are done (pyeloplasty first) seems to be crucial. Voiding cystography with appropriate postvoid drainage films, excretory urography, often with a catheter draining the bladder to prevent reflux, and provocative diuretic excretory urography and/or renography can determine that ureteropelvic junction obstruction does coexist and quantitate the severity of each problem.     

Contrast-enhanced ultrasonography (voiding urosonography) of vesicoureteral reflux: State of the art

Three methods are currently used to identify vesicoureteral reflux (VUR) in children, namely, radiographic voiding cystourethrography, radionuclide voiding cystography and, more recently, echo-enhanced voiding urosonography (VUS). Recent advances in tissue-harmonic and contrast-specific imaging techniques, together with the development of second-generation contrast agents, have improved the potential of ultrasonography both in the diagnosis and grading of VUR in children. Today, VUS is able to accurately assess the grade of reflux and the state of the urethra, previously considered fundamental limitations to the extensive use of this technique. The aim of our paper is to review the role of ultrasonography in the diagnosis of VUR, from the initial experiences up to the recent use of second-generation microbubbles combined with contrast-specific low-mechanical-index software. We discuss the advantages and limits of VUS with respect to radiographic and radionuclide imaging in the light of an analysis of the most recent literature, and we described the new VUS study technique using second-generation contrast media. Growing requests by paediatric nephrologists and surgeons require that even general radiologists become familiar with this technique.     

糖尿病性膀胱病的影像学诊断

目的：探讨糖尿病性膀胱病的影像学表现、检查方法及其诊断价值。方法：搜集14例糖尿病性膀胱病，具有完整的临床、实验室检查、B超及静脉尿路造影资料，作一回顾性分析。结果：糖尿病性膀胱病表现：膀胱体积增大，呈松塔样，边缘可光滑或有假憩室及结石形成，输尿管膀胱段返流，伴有双侧输尿管增宽、纡曲线或以一侧明显，不同程度肾积水。结论：结合病史、实验室检查、影像学检查，特别是静脉尿路造影（IVU）表现并综合分析，可明确诊断，但如同时合并糖尿病性肾病，宜行B超和膀胱逆行造影，以免出现急性肾功能不全。     

Retrograde echocystography: a new ultrasonographic technique for the diagnosis and staging of vesicoureteral reflux]

PURPOSE: We investigated the accuracy of a new US investigation technique, called retrograde cystography US, in the early diagnosis and staging of vesicoureteral reflux. MATERIAL AND METHODS: We examined 5 patients, aged 3 months to 10 years, suffering from hydronephrosis and/or pyelonephritis. Retrograde cystography US was followed by conventional retrograde cystography. Retrograde cystography US consists in the transcatheter introduction of a contrast agent (Levovist, Schering AG, Berlin, Germany) into the bladder and a subsequent color Doppler examination to show or exclude the presence of reflux. Superpubic scanning of bladder, ureters and pyelocaliceal cavity was performed after echocontrast agent introduction to assess the reflux grade. US was performed with an Esaote AU 590 asynchronous scanner (Esaote Biomedica, Genova, Italy) with a 3.5 MHz convex probe. RESULTS: After the transcatheter introduction of Levovist, vesicoureteral reflux was seen in 5/5 patients. Reflux grade was also measured with US and then confirmed at retrograde cystography. In a patient with pyelonephritis and no reflux at follow-up cystography, retrograde cystography US identified a unilateral reflux (grade 1). DISCUSSION AND CONCLUSIONS: Retrograde cystography US showed the echocontrast agent in the urinary tract and assessed the reflux grade in all 5 patients, which was then confirmed at cystography. In a patient with grade 1 unilateral reflux at cystography US, follow-up conventional cystography showed no reflux, which seems to confirm a higher sensitivity of the US technique. The total agreement of conventional and US findings seems to confirm the importance of the US method for the diagnosis and staging of vesicoureteral reflux.     

Urinary tract infections in children: renal ultrasound evaluation

Ultrasound may replace urography in screening pediatric patients with uncomplicated urinary tract infections but without vesicoureteral reflux. A child undergoing a first radiographic evaluation for urinary tract infection is initially examined by voiding cystourethrography. If reflux is present, urography is performed. If no reflux is present, the kidneys are evaluated by real-time ultrasound; urography may also be performed if the ultrasound examination is abnormal, equivocal, or inadequate. A total of 192 patients was evaluated with this protocol; 146 (76%) had no reflux and therefore were examined with ultrasound. One patient was found to have hydronephrosis and underwent surgical correction. This group of patients was compared with a similar group of 223 patients without reflux who were evaluated by urography prior to the institution of the ultrasound protocol; there was no significant difference between the two groups in upper urinary tract findings that influenced patient management.     

Cyclic cystography: diagnostic yield in selected pediatric populations.

PURPOSE: To test the hypothesis that the diagnostic yield of cyclic cystography is related to the prevalence of vesicoureteral reflux (VUR) in the population being evaluated. MATERIALS AND METHODS: Two groups of children were examined prospectively: 124 with severe urinary tract infection, defined as patient hospitalization or a maximum temperature greater than 39.5 degrees C, and 135 with previously diagnosed VUR. Nuclear cystography was performed in 249 patients, and fluoroscopic cystography was performed in 10. If VUR was not seen during the first cycle of bladder filling and voiding, a second cycle was performed. RESULTS: VUR was present during cycle 1 in 40 (32%) of 124 patients with severe urinary tract infection and 90 (67%) of 135 children in the VUR follow-up group (P < .001). VUR was demonstrated during cycle 2 in seven (9%) of 76 of the severe urinary tract infection group and eight (24%) of 34 of the VUR follow-up group (P = .045). Of 15 patients with VUR during cycle 2, two had grade III VUR and 13 had grade I or II VUR. CONCLUSION: The second cycle of cyclic cystography has a higher diagnostic yield in patients undergoing VUR follow-up than in patients with severe urinary tract infection. The decision to perform a second cycle of bladder filling and voiding should take into account the pretest probability of VUR in the child being examined.     

The value of Ga-67 renal SPECT in diagnosing and monitoring complete and incomplete treatment in children with acute pyelonephritis.

PURPOSE: This study evaluated the utility of Ga-67 renal SPECT for diagnosing acute pyelonephritis (APN) in children and monitoring them. METHODS: Seventy-one children (ages 1 week to 12 years) who were thought clinically to have APN were included in the study. The disease was considered present if the patients had all of the following: fever (38.5 degrees C), pyuria (leukocyte counts/per high-power field > or = 10), and a positive result of a urinary culture or blood culture. Tc-99m DMSA, Ga-67 renal SPECT, and voiding cystourethrography were performed, with informed consent from the patients' parents, within 3 days after hospitalization. Three months after treatment, Tc-99m DMSA and Ga-67 renal SPECT were repeated in those patients who had abnormal results of the initial Ga-67 renal SPECT. RESULTS: In the diagnostic study, Ga-67 renal SPECT was superior to DMSA renal SPECT in detecting lesions (97% vs. 79%). Three children had false-negative results with Ga-67 renal SPECT. Seventeen kidneys were negative with Tc-99m DMSA but positive with Ga-67 renal SPECT. No patients had any Ga-67 uptake on post-therapy imaging. However, 32 of 107 kidneys (30%) had permanent renal scars. In these 107 kidneys, 78 (73%) were associated with high-grade vesicoureteral reflux (VUR; VUR grade > or = 3) and 29 (27%) with low-grade or no VUR. CONCLUSIONS: High-grade VUR tends to be associated more with APN than has been reported by others, probably because of an underestimation of APN by ultrasonography or DMSA. Ga-67 renal SPECT is sensitive and useful not only in diagnosis but also for monitoring and follow-up of children with clinical suspicion of APN, especially in those with equivocal results after DMSA renal SPECT studies.     

The evaluation of gross hematuria in anticoagulated patients: efficacy of i.v. urography and cystoscopy

To determine the efficacy of investigating gross hematuria in anticoagulated patients, records were reviewed of 24 patients who had gross hematuria while being treated with warfarin for various thromboembolic disorders. All had IV urography, and half had cystoscopy. Sources of bleeding were found in seven (29%) of 24 patients by IV urography and in five (42%) of 12 patients by cystoscopy. Abnormalities considered responsible for bleeding included renal stones (four), transitional cell carcinoma (one), calcified renal mass (one), lymphoma (one), bladder tumors (two), hemorrhagic cystitis (two), and a bleeding prostate tumor (one). Additionally, an enlarged prostate was the only abnormal finding in five patients. If an enlarged prostate is considered a source of bleeding, the workup that included both IV urography and cystoscopy identified a cause of bleeding in 17 (71%) of 24 patients. The results suggest that IV urography and cystography are warranted in patients who take anticoagulants and who have gross hematuria.     

Investigation of vesicoureteral reflux with colour Doppler sonography in adult patients with spinal cord injury

The aim of the study was to evaluate prospectively the performances of colour Doppler sonography for detection of vesicoureteral reflux in adult patients with neurogenic bladder due to spinal cord injury. One hundred eighty-seven adult patients who had developed neurogenic bladder due to spinal cord injury underwent retrograde cystography and sonographic evaluation by B-mode and colour flow Doppler sonography (CFDS). Results of both examinations were analyzed independently by two radiologists. Representative images of the sonographic evaluations were recorded on videotape and CD-Rom. CFDS detected reflux in 20 ureters while retrograde cystography revealed vesicoureteral reflux (VUR) in 25 ureters of a total of 374 ureters, which were examined by both methods. Sonography detected all cases of grades IV and V of reflux, 7 of 8 (87.5%) of grade III, 5 of 6 (83.3%) of grade II, and 4 of 7 (57.14%) of grade I. There were 6 false-positive and 5 false-negative findings with Doppler examination compared with retrograde cystography. Therefore, sensitivity and specificity of sonographic examination were 80 and 98.28%, respectively, with a positive predictive value of 76.92%. Colour flow Doppler sonography can play an important role in detection of VUR in spinally injured adult patients with neurogenic bladder and can be an effective imaging tool for follow-up.     

Imaging of hematuria

Hematuria may have a number of causes, of which the more common are urinary tract calculi, urinary tract infection, urinary tract neoplasms (including renal cell carcinoma and urothelial tumors), trauma to the urinary tract, and renal parenchymal disease. This article discusses the current status of imaging of patients suspected of having urologic causes of hematuria. The role of all modalities, including plain radiography, intravenous urography or excretory urography, retrograde pyelography, ultrasonography, and multidetector computed tomography (MDCT) in evaluation of these patients is discussed. The article highlights the current status of MDCT urography in imaging of patients with hematuria, and discusses various-often controversial-issues, such as optimal protocol design, accuracy of the technique in imaging of the urothelium, and the significant issue of radiation dose associated with MDCT urography.     

Nuclear cystography and renal sonography: findings in girls with urinary tract infection

This retrospective study documents the findings on nuclear cystography and renal sonography of 455 girls who had urologic imaging for a proved urinary tract infection (UTI). Nuclear cystograms were normal in 313 (69%) of 455 patients. Vesicoureteral reflux was seen in 142 patients (31%): six with grade I, 90 with grade II, 43 with grade III, and three with grade IV. Twelve percent of patients with vesicoureteral reflux had renal parenchymal scars. Increasing grades of reflux were associated with an increase in the severity and number of parenchymal scars. Normal renal sonograms were seen in 83% of patients. Abnormalities noted on sonograms included parenchymal scarring in 31 (7%) of the 455 patients, anomalies in 19 patients (4%), mild to moderate dilatation of the renal pelvis and or ureters in 45 patients (10%), and bladder wall thickening in 45 patients (10%).     

Radiographic manifestations of congenital anomalies of the lower urinary tract

The evaluation of anomalies of the lower urinary tract (ureter, bladder, and urethra) requires high quality ultrasonography, voiding cystourethrography, and, occasionally, intravenous urography and contrast sinography. Infants with these anomalies present because of abnormal intrauterine ultrasonographic examinations, urinary tract infections, or obvious external malformations. With a solid embryologic knowledge of the development of the lower urinary tract the radiologist can tailor the imaging procedures to demonstrate almost all aspects of the anomaly and the presence or absence of frequently associated malformations.     

Targeted Delayed Scanning at CT Urography: A Worthwhile Use of Radiation?

Purpose: To determine whether ureteral segments not filled with contrast material at computed tomographic (CT) urography ever contain tumor detectable only by filling these segments with contrast material. Materials and Methods: In this institutional review board-approved, HIPAA-compliant retrospective study, with waiver of informed consent, databases were searched for all patients who underwent heminephroureterectomy or ureteroscopy between January 1, 2001, and December 31, 2009, with available CT urography findings in the 12 months prior to surgery or biopsy and patients who had undergone at least two CT urography procedures with a minimum 5-year follow-up between studies. One of two radiologists blinded to results of pathologic examination recorded location of unfilled segments, time of scan, subsequent filling, and pathologic or 5-year follow-up CT urography results. Tumors were considered missed in an unfilled segment if tumor was found at pathologic examination or follow-up CT urography in the same one-third of the ureter and there were no secondary signs of a mass with other index CT urography sequences. Estimated radiation dose for additional delayed sequences was calculated with a 32-cm phantom. Results: In 59 male and 33 female patients (mean age, 66 years) undergoing heminephroureterectomy, 27 tumors were present in 41 partially nonopacified ureters in 20 patients. Six tumors were present in nonopacified segments (one multifocal, none bilateral); all were identifiable by means of secondary signs present with earlier sequences. Among 182 lesions biopsied at ureteroscopy in 124 male and 53 female patients (mean age, 69 years), 28 tumors were present in nonopacified segments in 25 patients (four multifocal, none bilateral), all with secondary imaging signs detectable without delayed scanning. In 64 male and 29 female patients (mean age, 69 years) who underwent 5-year follow-up CT urography, three new tumors were revealed in three patients; none occurred in the unfilled ureter at index CT urography. Estimated radiation dose from additional sequences was 4.3 mSv per patient. Conclusion: Targeted delayed scanning at CT urography yielded no additional ureteral tumors and resulted in additional radiation exposure. ? RSNA, 2012.