Ureteral Jets Research Articles

Assessment of Obstruction in Adult Ureterocele by Means of Color Doppler Duplex Sonography

Aim: The purpose of this study is to present a method for identifying a ureteral obstruction in unilateral orthotopic ureterocele by means of conventional sonography and color Doppler duplex sonography. We focus on the measurement of the ureterocele dimensions, the degree of dilation it causes to the ipsilateral upper urinary tract, the registration of urine out-flow from the ureteral orifice into the bladder and its spectral analysis. Material and Method: Over 2 years at our institutions, 8 adult patients (7 women, 1 man) were diagnosed as having a single system orthotopic ureterocele. Four of them presented with lumbar pain, dysuria and recurrent urinary tract infections, while the remainder were asymptomatic and diagnosed accidentally. The diagnosis was based on serial sonography of the upper and lower urinary tract confirmed by intravenous pyelography and cystoscopy. We also performed color Doppler duplex sonographic evaluation of the urine jets ejected from both ureteral orifices into the bladder. Using the flow spectral study we analyzed the waveforms and measured their duration and flow rate. The study was completed with a comparative analysis of the data obtained from both ureteral orifices. Results: Cystic dilation of the lower ureteric extremity into the bladder was presented in all cases. Upper urinary tract dilation, of various grades, was present in 4 of 8 patients. Differences in urine jets between those derived from the ureterocele and those from the healthy contralateral ureteral orifice were significant in those patients with dilation of the upper urinary tract. The differences concerned mainly the frequency and symmetry of the jets as well as the pattern, duration and velocity of their waves. The 4 above-mentioned patients, with dilated upper urinary tracts and waveforms differentiated from the contralateral ones, were characterized as obstructive. On the other hand, the remaining 4 patients with subclinical ureterocele showed insignificant differences in urine jets and waveforms, and were found to be non-obstructive. Conclusion: Conventional sonography of the urinary tract in combination with color Doppler duplex sonography of the ureteral jets can be used in an attempt to diagnose and evaluate a unilateral orthotopic (single system) ureterocele and assess the necessity of intervention to identify the obstruction.

Investigation of loin pain

Evaluation of a patient presenting with acute loin pain is a common reason for emergency referral to a radiology department. In the majority of cases the prime diagnostic consideration will be colic due to a ureteric stone. Although most ureteric stones are sufficiently radio-opaque to be visible on a plain radiograph of the abdomen, they are frequently obscured by bony structures and bowel contents. Other abdominal calcifications, particularly phleboliths, can be impossible to differentiate from ureteric stones. For this reason a plain film alone is usually not adequate for diagnosis. IVU has been the traditional method of diagnosing ureteric calculi and although it has a high sensitivity in demonstrating ureteric obstruction it frequently cannot directly identify a stone as the cause. It also requires the use of intravenous contrast medium, exposes the patient to ionising radiation, and diagnosis may be delayed by the need for late films. Ureteric stones are usually difficult to identify with ultrasound, which instead relies on evidence of obstruction to indirectly indicate the presence of a stone. The presence of hydronephrosis lacks specificity in this regard but diagnostic accuracy may be improved by identifying changes in intrarenal blood flow that occur in acute obstruction and by the analysis of ureteric jets. In combination with a plain radiograph, ultrasound provides an acceptable imaging technique when CT is not available. The use of ultrasound is particularly attractive in patients presenting with loin pain in pregnancy in whom it should be the primary imaging investigation. Unenhanced spiral CT has now become the imaging technique of choice for most patients with flank pain, not only owing to its unrivalled ability to directly visualise ureteric stones, but also its speed and ease of use. It provides all the imaging information required for patient management. CT also has the major advantage of demonstrating many other possible causes of loin pain in patients that do not have ureteric stones. The radiation exposure of CT must always be considered, particularly in young patients and those with recurrent stone formation, and dose reduction techniques should be applied whenever possible.

Utility of sonography for the evaluation of suspected urolithiasis in pregnancy

Study objectives: We seek to evaluate the utility of sonography for the evaluation of suspected renal colic in pregnant patients. Methods: One radiologist retrospectively reviewed the radiology reports of all pregnant patients who presented to 1 institution during a 5-year period with suspected renal colic. All women who had at least 1 renal sonogram and the initial suspected diagnosis of renal colic were included. The official reports of the sonographic studies and of any additional relevant imaging studies were then reviewed. The presence or absence of a ureteral calculus, as well as hydronephrosis, was recorded. Potential indicators of ureteral obstruction on sonography, including abnormal color or power Doppler flow within the renal parenchyma, absence of ureteral jets, and elevated resistive indices of each kidney, were noted, if these observations were recorded. The results of any repeated sonographic studies during the course of the same pregnancy were also reviewed. The percentage of cases in which a ureteral stone was believed to be present was calculated. The percentage of cases in which a significant alternative diagnosis was believed to be established according to sonography was also calculated. Results: Seventy-seven women had at least 1 episode of suspected renal colic during pregnancy and also had at least 1 sonogram. Fifty-five of these women underwent a single study, and 22 underwent a total of 58 studies. Of the 22 women who underwent more than 1 study, 5 had 2 separate pregnancies in which sonography was performed for possible renal colic. There were only 2 women for whom a ureteral stone was reported at sonography (3.9% of women, 3.5% of examinations, 3.6% of pregnancies). The only alternative diagnosis established according to sonography was pyelonephritis, which was suggested in 1 woman and diagnosed in 2 others (3.9% of women, 2.7% of examinations, 3.6% of pregnancies). Only 1 woman had a magnetic resonance imaging urogram, which revealed no ureteral stone. Fifty-one percent of sonograms revealed some degree of unilateral or bilateral hydronephrosis. There was no consistent reporting of ureteral jets, resistive indices, or color or power Doppler analysis. Conclusion: Fewer than 5% of pregnant patients with suspected renal colic had that diagnosis established on sonography, fewer than 5% had an alternative diagnosis established, and only 1% underwent testing with a different imaging modality. Although the actual incidence of urolithiasis in these pregnant patients was unknown, the utility of routine sonography is questioned, and alternative testing such as magnetic resonance imaging urography should be considered when clinically indicated.

Functional evaluation of the urinary tract by color-Doppler ultrasonography (CDU) in 100 patients with renal colic

Introduction and objective: To evaluate if the addition of a renal color-Doppler ultrasonography (CDU) in the setting of acute renal colic improves the sensitivity of conventional sonography. Materials and methods: Between July 2002 and June 2003, 100 patients (median 49 years) with renal colic have been evaluated. Within 24 h of the admission, a CDU study of the urinary tract was performed using a sonograph GE Logiq 500 PRO with a multifrequency (3–5 MHz) convex probe. The following parameters were evaluated: ultrasonography (US) of both kidneys, ureters and bladder; resistive index (RI) of the arciform arteries of both kidneys in three different parenchymal areas; ureteric jets in response to hydration. A renal RI >0.70 and/or a 10% difference between the kidneys were considered as diagnostic of obstructive uropathy; an asymmetric and/or reduced ureteric jet from the ureteric orifices was an additional indicator of obstruction. All patients underwent a CT scan both with and without the administration of contrast medium. Results: Enhanced helical CT demonstrated an urinary stone in 90 out of the 100 patients (90%): 29 pyelic, 28 at the pyelo-ureteral junction, 23 lumbo-iliac and 10 juxtavesical stones. Among 90 patients with urolithiasis, the stone was undetectable with US in 11 cases (12.2%); in 8 cases (8.9%) pyelocalicectasis was absent, and in 6 patients (6.6%) a non-obstructive hydronephrosis was present. Median RI in obstructed and non-obstructed kidney was 0.73 (range 0.71–0.87) versus 0.62 (0.50–0.68), respectively; in two, obstructed kidneys RI was <0.70 but greater than 10% compared with normal side. Sensitivity and specificity of US, CDU (RI + ureteric jet), unenhanced helical CT and CDU in association with unenhanced helical CT were 94.8 and 55.5, 98.9 and 90.9, 100 and 100%, respectively. Discussion and conclusions: CDU in patients with renal colic and/or pelvicalicectasis improves the diagnostic accuracy of US in distinguishing between obstructive and non-obstructive dilatation. Combined with unenhanced CT, CDU has a 100% sensitivity and specificity. Moreover, due to the absence of contraindications and side-effects, CDU is indicated for the follow-up of patients after ESWL, pregnant women and children.

Ureteric jet in the anaesthetised child

We have already suggested that there is an active bimodal sphincteric mechanism in the human vesicoureteral junction (VUJ). This mechanism is affected by immaturity, hormonal effects and surgical ablation. This study set out to investigate the effects of anaesthesia on this mechanism. A total of 16 children undergoing surgery were recruited. They were well hydrated. The ureteric jets before and after anaesthesia were recorded using the colour and pulse wave Doppler. Of the total, 14 children showed mature (complex pattern) and two showed immature (monophasic pattern) waveforms before surgery. After anaesthesia, all showed the monophasic waveform ( p = 0.01). Thus, the sphincteric action of VUJ as manifest by the complexity of the ureteric jet was modified by anaesthesia by loss of the complex pattern. This supports the hypothesis that the complex pattern is a neural modulation of the simpler myogenic mechanism that produces the monophasic jet. (Email: leuyf2@ctimail.com)

Paediatric Doppler—kidney

Renal Doppler imaging has been successfully performed, as the blood flow in a normal kidney is important, resulting in a high Doppler signal level. Several Doppler techniques can be used, including color, amplitude, and duplex modes. A precise knowledge of their respective benefits and limitations allows for the appropriate choice, a better optimisation of technical settings in a given patient, and a good understanding of normal vascular anatomy and hemodynamics. From a practical point of view, the wish of a good sensitivity to low blood flow is often compromised by motion artifacts. Other modalities, such as Dynaflow and non-Doppler techniques, have been recently introduced, leading to a better spatial resolution. The actual trend to use higher transmission frequencies further improves the spatial resolution, and increases the sensitivity to flow. New softwares have been introduced, in the attempt to reduce motion artifacts. Clinical applications of Doppler include the detection and follow-up of renal vein or artery thrombosis, the diagnosis of acute pyelonephritis, the evaluation of vascularity of renal tumors and pseudotumors, the detection of crossing vessels in UPJ syndromes, and the follow-up of patients after renal transplantation. Ureteral jets may be an adjunct for the diagnosis of obstruction of the upper urinary tract in some cases. Doppler has been used for the detection of vesico-ureteral reflux, but now contrast-enhanced US appears more sensitive and reliable.

Ultrasound of acute renal problems

The most common acute renal problems prompting request for imaging are acute renal failure, infection, and pain with possible stone disease. For patients with acute renal failure, management depends on determination of prerenal (hypoperfusion), renal, or postrenal (obstructive) cause. Diagnosis and treatment can frequently be based upon careful analysis of patient history, symptoms/signs, and urine/blood laboratory analysis. However, the clinical picture is often inconclusive, and ultrasound is the primary imaging modality in this evaluation. Ultrasound evaluation includes determination of renal size, presence of focal or generalized renal scarring, and evaluation for hydronephrosis/hydroureter. Renal Doppler is used to confirm renal arterial and venous patency and to evaluate resistive indices in intrarenal vessels, which may help determine presence of parenchymal disease and prognosis in some situations. Imaging of the urinary bladder, including presence or absence of ureteral jets, is essential in patients with possible obstructive uropathy. Patients with acute pyelonephritis are also commonly managed based on clinical parameters, but require imaging with clinical suspicion of pyonephrosis (infection in an obstructed collecting system) or abscess. Ultrasound or contrast-enhanced computed tomography can be effective in this situation. Advantages of ultrasound include its portability, ability to guide invasive procedues, and lack of ionizing radiation. CT may be more sensitive to abscess/pyonephrosis in some situations, especially with obese patients. Patients with acute flank pain and hematuria may be imaged with ultrasound to evaluate for signs of obstruction and stones. Lack of sensitivity for stones and early obstruction limits this evaluation, but some find the addition of Doppler useful. In pregnant patients, ultrasound is most appropriate, but in other populations CT is often preferred.

Immature ureteric jet doppler patterns and urinary tract infection and vesicoureteric reflux in children

The Doppler waveform of the ureteric jet is the result of modification of ureteric peristalsis by an active sphincteric mechanism of the vesicoureteric junction (VUJ). The monophasic pattern is associated with immaturity. This study set out to see the correlation between this immature pattern with urinary tract infection (UTI) and vesicoureteric reflux (VUR) in children. Ureteric jets of 241 healthy children and 98 children with UTI were studied. The monophasic pattern was found in 29% of healthy children overall, but varied greatly according to age. The monophasic pattern was virtually universal in the first 6 months of life, dropping to below 15% in late childhood. This immature pattern was more commonly seen in the UTI (73.5%) and VUR (90.5%) groups than in the healthy controls. The difference was statistically significant ( p = 0.0005 for both). The persistence of this immature pattern was highly associated with UTI and VUR.

The ureteric jet doppler waveform as an indicator of vesicoureteric sphincter function in adults and children.: An observational study

The nature of the action of the vesicoureteric junction (VUJ) in humans is still controversial. We were interested in the reasons why the jet consists of several peaks. We hypothesised that the modification of the jet into a variable number of peaks is the result of an active sphincter mechanism at the VUJ. A total of 1010 subjects of all ages and both genders were recruited into this study. The Doppler waveform of the jet was recorded bilaterally. We could identify six basic patterns of ureteric jet according to the number of peaks: monophasic, biphasic, triphasic, polyphasic (four or more peaks), square and continuous. By analysing the duration, maximum peak velocity and initial slope of the first four patterns, a mechanism of action of an active VUJ sphincter could be postulated. Furthermore, the basic patterns could be assigned to three modes of ureteric actions: the square and continuous are only seen during diuretic stress; the biphasic, triphasic and polyphasic patterns are variations of the adult physiological steady-state mode, and the monophasic is distinctly different and represents the immature mode.

Doppler waveform of the ureteric jet in pregnancy

We have shown that the function of the bladder vesicoureteric junction (VUJ) can be studied by the Doppler waveform of the ureteric jet, and this reflects the active sphincteric mechanism of the VUJ. We wished to investigate if the hormonal changes of pregnancy cause any alteration of VUJ function. A total of 107 pregnant women and 375 nonpregnant women were recruited. Three scans, 20 and 32 weeks of gestational age and 3 months postpartum, were done. The occurrence of a monophasic waveform in the nonpregnant group was 1.9%. In the pregnancy group, this was 18.7%, 41.1% and 1.6% at 20, 32 weeks of gestational age and 3 months postpartum, respectively. The difference in occurrence of the monophasic waveforms was statistically significant (both p = 0.0005 at 20 and 32 weeks). This suggests an adverse hormonal effect on the vesicoureteric junction during pregnancy, and may be a factor in the increased risk of UTI in pregnancy.

Ureteric jet in renal transplantation patient

We have made a case for an active sphincteric mechanism at the VUJ modifying the ureteric jet Doppler waveform. The transplanted ureter does not have a normal VUJ, but retains inherent peristalsis. This study was to document any difference in the transplanted ureteric jet Doppler pattern. A total of 55 transplant patients and 817 healthy subjects were recruited. The Doppler waveform of the transplanted ureter is distinctly different from that of the healthy adult ureter. There are two major patterns: a short monophasic waveform is the most common (66.1% vs. 2.6% in healthy ureters). Less common is a longer, more phasic, pattern, which, however, does not resemble the patterns of the healthy ureter. This supports the hypothesis that the mode of action at the VUJ is sphincteric, because this is lost with transplantation, and ureteric drainage reverts to a simple unmodified pattern.

Prospective evaluation of ureteral stent durability in patients with chronic ureteral obstruction

Objectives. To prospectively evaluate the durability of ureteral stents in patients with chronic ureteral obstruction. Methods. Twenty-nine renal units from 22 patients with known chronic ureteral obstruction treated with indwelling ureteral stents were studied at 3, 6, 9, and 12 months after initial stent placement (7 to 8F Percuflex) by abdominal x-ray, serum creatinine, and renal and bladder ultrasonography. Renal ultrasound scans were performed by a single senior radiologist with specific attention paid to any increase in hydronephrosis and to the presence of ureteral jets. The stent was changed when calcifications were seen along the stent on abdominal x-ray, if an increase in serum creatinine occurred, or if any increase in hydronephrosis or absence of ureteral jets was seen on ultrasonography. In addition, the stents were changed if new-onset flank pain and/or pyelonephritis developed. If none of the above occurred, the stents were changed after 12 months. Results. Two patients died of metastatic cancer, leaving 25 renal units available for follow-up. The mean and median time to stent change were 6 months. At 3, 6, 9, and 12 months, the number of renal units that did not meet the criteria warranting stent change was 18 (72%), 12 (48%), 6 (24%), and 2 (8%), respectively. Only 2 (8%) of 25 renal units did not meet any exclusion criteria at 12 months. The most common reasons for requiring the stent to be changed were new-onset flank pain in 8 (35%), an increase in serum creatinine in 7 (30%), and new-onset or increased hydronephrosis in 7 (30%). No criteria were useful in predicting how long stents could be maintained in an individual patient. Conclusions. The stents were maintained for more than 6 months in 12 (48%) of 25 renal units. However, very few patients were able to maintain chronic ureteral stents for 12 months without requiring stent change based on our criteria.

Colour Doppler evaluation of ureteral jets in normal second and third trimester pregnancy: effect of patient position

The study was designed to investigate the effect of patient position on the detection of ureteral jets in normal pregnancy. The number of jets was recorded for 1 min using colour Doppler ultrasound in 26 healthy asymptomatic gravid women between 16 weeks and 34 weeks gestation. Each patient was examined in the supine position and in both the right and left lateral decubitus positions. Ureteral jets were present on at least one side in 24 patients in the supine position compared with 26 women in the lateral decubitus position. 13 (54%) of the 24 patients in whom jets were seen in the supine position had jets on only one side. A mean of 1.80 jets x min(-1) was detected on the right side and 3.23 jets x min(-1) on the left (p=0.046) in the supine position. In the contralateral decubitus position, jets were detected on the right side in 22 (85%) women and on the left in 25 (96%) women. A mean of 3.07 jets x min(-1) was detected on the right and 4.15 jets x min(-1) on the left. The difference in the frequency of ureteral jets between the supine and lateral decubitus positions was significant (p=0.004 for the right; p=0.011 for the left). However, the difference in the detection rate was significant on only the right side (p=0.016 for the right; p=0.063 for the left). 10 (77%) of 13 patients in whom unilateral absence of ureteral jets was noted had detectable jets in the lateral decubitus position. Our findings demonstrated the utility of the lateral decubitus position in the evaluation of ureters suspicious for obstruction. However, caution is still recommended in diagnosing ureteral obstruction if jets are persistently absent after this manoeuvre.

Color Doppler ultrasonography in the assessment of vesicoureteric reflux in children with bladder dysfunction.

To determine whether color Doppler ultrasound (DUS) evaluation of ureteric jets could predict vesicoureteric reflux (VUR) in children with non-neuropathic and neuropathic bladder/sphincter dysfunction, 129 children were evaluated to identify the vesicoureteric orifice and measure the distance from the orifice to the midline of the dorsal bladder wall (MVU distance). The type of bladder dysfunction was determined by urodynamic studies. Forty-two children with no history of kidney or bladder disease were examined by DUS as a control group. MVU distances were compared between several groups of children with different urodynamic findings, and the significance was tested. Jets were visualized in 81% of children. MVU distances were significantly lower in children without VUR compared to those with VUR. No statistically significant differences were observed between children without VUR and those with VUR and more severe urodynamic disturbances like dysfunctional voiding. In children with neuropathic bladders, jets were visible in only 57% of refluxive units and the range of MVU distances was very wide (5-22 mm). If a cut-off point of 10 mm is used, in children without bladder dysfunction the sensitivity of MVU measurement in the diagnosis of VUR was 87.5% and the specificity 97%. However, in children with non-neuropathic and neuropathic bladder dysfunction, the sensitivity was only 55% and the specificity 79%. Color Doppler (DUS) and measurement of the MVU distance proved useful in predicting VUR only in children with normal bladder function. In children with neuropathic and non-neuropathic bladder dysfunction it can be used to visualize ureteric jets, but cannot replace radiographic or radionuclide voiding cystourethrography.

Doppler visualization of ureteric jets in unilateral hydronephrosis in children and adolescents

Objective: to evaluate Doppler visualization of ureteric jets in the assessment of unilateral kidney collecting system dilatation in children and adolescents. Methods and patients: color Doppler ultrasonography was performed in 27 patients with hydronephrosis (11 female, 16 male, age range 3–21 years, mean age 10.5±4.4). Nine had acute obstruction due to ureteral calculus, seven had obstructive hydronephrosis due to uretero-pelvic junction (UPJ) stenosis, and 11 had non-obstructive hydronephrosis. Doppler was also performed in 32 healthy children (15 boys and 17 girls, age 2–17 years, mean age 7.8±3.9), who represented the control group. Results: in the control group jets were visible in 57 out of 64 ureteric units (89%). The mean frequency of jets in healthy children was 4.1 jets per min. In all children with hydronephrosis, jets were visible in 25 out of 27 normal ureteric units (92.6%), and their mean frequency was 4.5 jets per min. In children with acute unilateral colic, ureteric jets were completely absent in eight of nine patients (89%). In children with obstructive hydronephrosis, due to UPJ stenosis, jets were absent in five out of seven patients (71.4%), and in children with non-obstructive hydronephrosis jets were absent in three out of eleven patients (27.3%). When jets are visible, their frequencies are much lower on the obstructed side as compared with normal side, while in cases of nonobstructive dilatation frequency of jets is similar on both sides. Conclusion: absence of jets in patients with acute obstruction due to ureteral calculus, strongly correlates with high-grade obstruction. In children with UPJ stenosis, presence of ureteric jet does not exclude significant obstruction, but the frequency of jets on the obstructed side is much lower as compared with the unaffected side. When there is absence of jet from the dilated side or significant asymmetry in jet frequency, hydronephrosis is likely to be obstructive.

Jet Findings After Extracorporeal Shock Wave Lithotrispy for Ureteral Stone: Report of a Case

A female patient received laparoscopic total hysterectomy for uterine leiomyoma. Sonographic examination over bilateral ureteral jets, bilateral kidneys and gynecologic pelvis was done during a routine examination for all high-risk ureteral injury patients in our study. A dilated left renal pelvis, about 2.5 cm in diameter which mimicked a postoperative ureteral injury, was detected. After intravenous pyelography evaluation, a stone was found in the left ureter. The patient received extracorporeal shock wave lithotrispy (ESWL). Serial sonography and kidney-ureter-bladder X-ray films were done during follow-up. Initially the left ureteral jet was absent after ESWL but reappeared two weeks after ESWL. Thus, routine ureteral jet and bilateral renal sonography for patients who have undergone advanced laparosocopic surgery is a simple and effective method for detecting urinary track injury and ureteral stones. It can also play an important role in the follow-up examination of patients with ureteral stones after ESWI.

Evaluation and validation of ureteric jet index by glomerular filtration rate.

Ureteric jet index (UJI), a newly developed technique derived from color Doppler ultrasonography, may hold promise in evaluating renal function because of its ability to evaluate individual renal function and the use of nonionizing radiation. To assess the usefulness of UJI, the authors in this study analyzed the relation between UJI and the glomerular filtration rate (GFR). Fifteen adult patients with a wide range of renal function were included in this study. Subjects were well hydrated before color Doppler ultrasonography examinations. The UJI formula was: Vmean (average jet velocity) x D (jet duration) x F (jet frequency). GFR was calculated by the radionuclide method. Correlations between UJI, serum creatinine, and GFR were analyzed. Ureteric jet index had only a fair correlation with GFR. The coefficient of correlation value was 0.61, and the standard error of estimate of GFR was 17.9 mL/min. With the measurement of UJI, color Doppler ultrasound can provide both structural images and individual renal function information. It could substitute for a renal scan in determining individual renal function when a radionuclide examination is unavailable. Even if a renal scan were available, UJI can play a valuable role in the ultrasound examination of patients with suspected impaired renal function, providing further assessment of individual renal function.

Color flow Doppler sonography: a reliable alternative to voiding cystourethrogram in the diagnosis of vesicoureteral reflux in children

Objectives. In children with urinary tract infection, the incidence of vesicoureteral reflux (VUR) is nearly 30% to 40%. The standard for the diagnosis of VUR is voiding cystourethrography (VCUG). This study assessed the role of color flow Doppler sonography (CFDS) in the diagnosis of VUR and ureteral jets. Methods. CFDS imaging was performed in 36 patients aged 6 months to 13 years during a 4-year period. All patients underwent CFDS and VCUG within 24 to 48 hours, but the findings of the VCUG were not reported to the sonologist. The ultrasound examinations were done using a color Doppler real-time machine. Representative images of the bladder events were recorded with a multiformat camera and on VHS videotape. Results. The duration of the Doppler signal varied from 0.4 to 7.5 seconds. In 31 (86.1%) of 36 patients, the results of CFDS correlated well with VCUG findings. There were three false-negative and two false-positive results in the present study. Six patients underwent reimplantation during the course of their treatment. CFDS was used as a follow-up modality at the end of 6 months, and the results correlated well with standard VCUG in 4 of these patients. In the remaining 2 patients, only CFDS was performed and correlation with VCUG was not possible. VCUG was considered the reference standard in assessing the sensitivity of CFDS. Conclusions. CFDS of the bladder during the filling and micturating phases is a reliable and sensitive modality for identifying VUR and demonstrating ureteral jets. CFDS nullifies the danger of exposure to ionizing radiation and avoids the unpleasant catheterization many of these children fear.

Unilateral absence of ureteral jets in the third trimester of pregnancy: pitfall in color Doppler US diagnosis of urinary obstruction.

Among 23 asymptomatic pregnant women with ureteral jets noted at color Doppler ultrasonography, jets were detected at only one ureteral orifice in three (13%) during the third trimester. In each such case, normal jets were detected from the suspicious ureter after the patient turned to the contralateral decubitus position. A unilaterally absent jet noted in the third trimester of pregnancy should not be interpreted as a sign of ureteral obstruction unless the finding persists in the contralateral decubitus position.

Ultrasonographic detection of ureteral jets in normal pregnancy

Objective: Our purpose was to determine the impact of normal physiologic urodynamic alterations of pregnancy on the detection of ureteral jets into the bladder with use of transabdominal color Doppler ultrasonography. Study Design: We conducted a prospective cohort study of 125 healthy asymptomatic gravid women without any history of past or current renal disease, all with singleton pregnancies between 13.4 and 37.7 weeks' gestation. Right and left ureteral jets were recorded over a 5-minute period with use of color Doppler transabdominal ultrasonography and a full bladder. Each kidney was graded by the severity of the hydronephrosis. No hydronephrosis was grade 0, mild hydronephrosis was grade 1, and moderate hydronephrosis was grade 2. There were no cases of severe hydronephrosis. Results: There were 56 grade 0 cases on the right versus 93 grade 0 cases on the left ( p < 0.0001), 53 versus 30 grade 1 cases (right vs left, p < 0.003) and 16 versus 2 grade 2 cases (right vs left, p < 0.0009). In the subgroup where both kidneys were grade 0 the mean number of right ureteral jets 5 mm was 14.7 versus 15.1 for the left ureteral jets ( p = 0.73). In the grade 1 subgroup mean right versus left ureteral jets was 15.4 versus 16.6 ( p = 0.65). For the grade 2 subgroup mean right versus left ureteral jets was 15.5 versus 21.0 ( p = 0.32). There were 4 of 125 unilateral absent ureteral jets on the right versus 0 of 125 on the left ( p = 0.122). Conclusion: Our data demonstrate that ureteral jets can be readily detected during pregnancy independent of the gestational age. In addition, it does not appear that the physiologic urodynamic alterations of pregnancy affect the frequency or symmetry of ureteral jets. Thus identification of ureteral jets can be used in the workup of suspected urolithiasis in pregnant patients. (Am J Obstet Gynecol 1998;178:1194-8.)