Bladder Post-void Residual Volume Research Articles

Long-Term Urethral Function Measured by Uroflowmetry After Hypospadias Surgery: Comparison with an Age Matched Control

Long-term outcomes of hypospadias surgery, particularly urinary function, have not been examined thoroughly. Uroflowmetry can be used to evaluate long-term functional outcomes by assessing flow shape and the rate of micturition. We assessed urethral function using uroflowmetry in adolescents after undergoing hypospadias repair in infancy and compared this with age matched controls. After human research ethics committee approval (HREC 28111A), 17 boys 13 to 15 years old with no history of urological or neurological disorders underwent uroflowmetry (65 separate voids) to determine standard values for boys of this age. Then 60 boys age 13 to 15 years who had undergone treatment for hypospadias in early infancy were seen for long-term followup and underwent uroflow assessment. Standard urinary flow rates were established in the 13 to 15-year-old control group and represented on a nomogram. In the boys who underwent hypospadias surgery the urine flow rates were significantly lower compared to the control nomogram (p <0.0001), with half the patients having uroflow rates below 1 SD from the control mean but without symptoms. Boys with significant preoperative chordee were more likely to have poorer urinary flow (p <0.04). A poor urinary flow rate also was significantly associated with post-void residual bladder volume (p <0.03). There was no correlation with original meatal location, number of operations, presence of postoperative complications, current anatomy and lower urinary tract symptoms (eg post-void dribble, hesitancy, incontinence). At long-term followup after hypospadias surgery urinary flow rates were significantly lower compared to age matched controls but still fell within the normal range. In the hypospadias cohort there was no significant association with lower urinary tract symptoms and poor urinary flow. Detection of poor urinary flow may indicate incomplete bladder emptying. The presence of severe chordee preoperatively is a significant risk factor for poor urinary flow rates on long-term followup.

A multicentre single-blind randomized controlled trial comparing bipolar and monopolar transurethral resection of the prostate

Monopolar transurethral resection of the prostate (TURP) is the gold standard surgical therapy for men with lower urinary tract symptoms due to benign prostatic hyperplasia. Although generally considered safer, TURP experience is limited in Canada. Forty-three patients from 5 Canadian centres were randomized to TURP with either bipolar or monopolar platforms. Patients underwent baseline determinations of American Urological Association (AUA) symptom score, peak urinary flow rate, post-void residual bladder volume and transrectal ultrasound prostate volume. Primary outcome measures were improvement in AUA symptom score, quality of life assessment and bother assessment. Secondary outcomes included procedural times, duration of catheterization, length of hospitalization, complications and the degree of thermal artifact in tissue specimens. Patients were followed for 6 months. Twenty-two patients were treated with bipolar and 21 with monopolar TURP. Preoperative demographics were not statistically different between groups. Postoperative data collection times were equivalent in AUA symptom, quality of life, bother and sexual function assessments. No differences were observed in the procedure time (60.7 min, bipolar vs. 47.4, monopolar) or the duration of urethral catheterization (1.5 days, bipolar vs. 1.1, monopolar). More patients in the bipolar group were discharged on the same day of surgery. There were no differences in the degree of tissue thermal artifact or complication rate. This trial suggests equivalent short-term outcomes for men undergoing monopolar or bipolar TURP.

Evaluation of Sevoflurane as an Anesthetic Agent for Voiding Cystourethrography in Pediatric Patients

BackgroundSevoflurane anesthetic has recently been administered by anesthesiologists during voiding cystourethrograms in a centre where radiologists are not permitted to deliver pediatric sedation. ObjectiveTo determine whether sevoflurane is a satisfactory anesthetic agent for voiding cystourethrography in children. MethodsRecords of children undergoing voiding cystourethrogram while they were under sevoflurane were reviewed for anesthetic adverse effects and diagnostic quality of the cystourethrogram. The occurrence of on-table voiding and post-void residual bladder volume were documented and compared with an age- and sex-matched control group of children undergoing unsedated voiding cystourethrography. The caregivers were surveyed regarding the anesthetic experience. ResultsA total of 91 children underwent sevoflurane voiding cystourethrography; there were no adverse cardiorespiratory events. Voiding was observed in 96%, with residual bladder volumes minimal in 38%, moderate in 32%, and large in 28% of anesthetized children, not significantly different from the control group. Vesicoureteral reflux was observed in 53% of examinations under sevoflurane. When children with a previous history of reflux or voiding cystourethrography were excluded in a comparison with age- and sex-matched controls, vesicoureteral reflux was observed in 38% of studies under sevoflurane and in 44% of studies in the control group, P = .69; 85% of caregivers of children with prior unsedated voiding cystourethrography found voiding cystourethrography with sevoflurane easier than without sevoflurane; 89% thought the anesthetic experience reduced their child's anxiety towards medical procedures. ConclusionNo adverse events or effects on diagnostic quality of the pediatric voiding cystourethrogram were encountered when using sevoflurane. The majority of surveyed caregivers thought that anesthesia made voiding cystourethrography an easier experience for their child.

S18 DIAGNOSTIC VALUES OF DETRUSOR WALL THICKNESS, POSTVOID RESIDUAL URINE AND PROSTATE VOLUME TO EVALUATE LOWER URINARY TRACT SYMPTOMS IN MEN

277 L ower urinary tract symptoms (LUTS) are common, affecting approximately 40% of older men (1). LUTS is a recent term for what used to be known as prostatism (2). However, obstructive disorders of the lower urinary tract may also be caused by other diseases, such as bladder neck contractures, urethral valves, or external sphincter dyssynergia. However, for the majority of cases in the male population, the etiology is benign prostatic hyperplasia (BPH). Various animal and human studies have revealed that a significant enlargement of the bladder wall is attributable to smooth muscle cell hypertrophy, fibrocyte hyperplasia, and collagen deposition in the detrusor (3, 4). From a clinical perspective, thickening of the bladder wall should be considered as a sign of significant subvesical obstruction (5). The best way to visualize this detrusor muscle hypertrophy in a noninvasive manner is to measure the detrusor wall thickness (DWT) by suprapubic ultrasonography. In 2006, Belal and Abrams (6) evaluated noninvasive methods used to diagnose bladder outlet obstruction (BOO) in a meta-analysis and observed that ultrasound measurements of the DWT and bladder weight were the only predictors of subvesical obstruction in LUTS patients. It is widely accepted that DWT decreases continuously while the bladder fills to 50% of its capacity and then remains constant until 100%. Therefore, the detrusor wall measurements are performed on patients when the bladder is filled to maximum capacity only (7). However, no study has been published that evaluates the diagnostic accuracy of DWT when the bladder is empty. In our study, we investigated the association between the LUTS severity and DWT. In addition, the parameter “DWT when the bladder was empty” was also evaluated as a noninvasive diagnostic tool to predict LUTS in men. An ideal assessment tool to detect LUTS must be noninvasive, quick, inexpensive, and reproducible with high diagnostic accuracy. Ultrasonography has all of these criteria with additional advantages (no contrast material and no ionizing radiation). In uro-radiology practice, conventional ultrasound-derived noninvasive tests for the evaluation of LUTS severity can achieve measurements of DWT, postvoid residual urine volume (PVR), and prostate and bladder volumes. Hence, our primary aim in this prospective, controlled clinical study was to analyze the diagnostic accuracy of these ultrasound-derived noninvasive tools (i.e., DWT when the bladder is full and empty, PVR, and bladder and prostate volumes) in healthy, mildly symptomatic, and moderately-toseverely symptomatic men, and compare the outcomes in each group. In addition, their correlation according to International Prostate Symptom Score (IPSS) and age groups as well as differences in DWT values were also investigated. Our hypothesis was that these tests would accurately discriminate symptomatic cases from healthy subjects and would ABDOMINAL IMAGING

MR Imaging–guided Cryoablation for the Treatment of Benign Prostatic Hyperplasia

A patient with benign prostatic hyperplasia presented with chronic lower urinary tract symptoms despite prior surgery and continued medical therapy. Using a magnetic resonance imaging–guided transperineal approach, two cryoprobes were placed into the transition zone of the prostate gland, and two cryoablation freeze-thaw cycles were performed. At 10 weeks after treatment, the frequency of nocturia had decreased from once every 1.5 hours to once per night, urinary peak flow rates had increased from 5.1 mL/s to 10.3 mL/s, and postvoid residual urinary bladder volume had decreased from 187 mL to 58 mL. Improved flow rates and symptoms remained stable 16 weeks after treatment.

Patient preferences for clean intermittent catheterisation and transurethral indwelling catheterisation for treatment of abnormal post-void residual bladder volume after vaginal prolapse surgery

To determine patient preferences for clean intermittent catheterisation (CIC) relative to transurethral indwelling catheterisation (TIC) as the treatment of abnormal post-void residual bladder volume (PVR) following vaginal prolapse surgery. Scenario-based preference assessment during face-to-face interview. Teaching hospital. A sample of consecutive patients scheduled for vaginal prolapse surgery. Preference for CIC relative to TIC was assessed using written treatment scenarios. Initially, treatment duration was set at 3 days and the risk for urinary tract infection (UTI) was 30% for both interventions. Both treatment duration and UTI risk related to TIC were kept constant. Treatment duration and UTI risk after CIC were varied until patients altered their preference. In this way, the duration of catheterisation and level of UTI risk related to CIC at which patients would prefer CIC to TIC could be determined. Patients' preference for CIC relative to TIC. When both duration of treatment and UTI risk were identical for both interventions, 64% of patients prefer CIC. Ninety-two percent of patients prefer CIC when CIC lasts 3 days but results in a 15% lower risk of UTI. Assuming that CIC results in a 15% risk of UTI, a total of 98 and 99% of patients prefer CIC to TIC when catheterisation with CIC last 2 and 1 day, respectively. Most patients with abnormal PVR prefer CIC to TIC. The results of a recent randomised controlled trial showed that CIC resulted in a 2 days shorter catheterisation and more than 20% reduced risk of UTI. These conditions correspond to a preference of 99% of patients for CIC.

Comparing clean intermittent catheterisation and transurethral indwelling catheterisation for incomplete voiding after vaginal prolapse surgery: a multicentre randomised trial

To compare clean intermittent catheterisation with transurethral indwelling catheterisation for the treatment of abnormal post-void residual bladder volume (PVR) following vaginal prolapse surgery. Multicentre randomised controlled trial. Five teaching hospitals and one non-teaching hospital in the Netherlands. All patients older than 18 years experiencing abnormal PVR following vaginal prolapse surgery, with or without the use of mesh. Exclusion criteria were: any neurological or anxiety disorder, or the need for combined anti-incontinence surgery. All patients were given an indwelling catheter directly after surgery, which was removed on the first postoperative day. Patients with a PVR of more than 150 ml after their first void were randomised for clean intermittent catheterisation (CIC), performed by nursing staff, or for transurethral indwelling catheterisation (TIC) for 3 days. Bacteriuria rate at end of treatment. A total of 87 patients were included in the study. Compared with the TIC group (n = 42), there was a lower risk of developing bacteriuria (14 versus 38%; P = 0.02) or urinary tract infection (UTI; 12 versus 33%; P = 0.03) in the CIC group (n = 45); moreover, a shorter period of catheterisation was required (18 hours CIC versus 72 hours TIC; P < 0.001). Patient satisfaction was similar in the two groups, and no adverse events occurred. Clean intermittent catheterisation is preferable over indwelling catheterisation for 3 days in the treatment of abnormal PVR following vaginal prolapse surgery.

Assessment of Postoperative Postvoid Residual Bladder Volume Using Three-Dimensional Ultrasound Volumetry

The aim of our prospective study was to assess the concordance between postvoid residual volumes (PVR) of the urinary bladder obtained by two different three-dimensional (3-D) ultrasound (US) volumetric methods (VOCAL and XI VOCAL) and with measurement by the catheter in postoperative patients who have undergone radical hysterectomy. The 3-D sonographic volume-determination of PVR with both methods correlated significantly with the actual amount of PVR by the catheter. The accuracy of both 3-D US volumetric methods was significantly higher under 300 mL of PVR. Bland–Altman plots were generated to examine limits of agreement. Both noninvasive 3-D sonographic methods are appropriate for the correct volume-determination of PVR following radical hysterectomy. Thus, we may avoid routine, albeit often unnecessary, catheterization to measure postoperative residual bladder volumes and subsequently the incidence of lower urinary tract infection may be reduced and better postoperative comfort for patients may be permitted. (E-mail: szabolcs.bozsa@aok.pte.hu)

Postpartum urinary retention after vaginal delivery

Objective To determine the incidence of covert and overt postpartum urinary retention (PUR) after vaginal delivery and to determine obstetric variables contributing to PUR. Methods In a cross-sectional study, women who delivered vaginally underwent a transabdominal ultrasound scan for estimation of postvoid residual bladder volume and diagnosis of PUR. Patient data, including age, obstetric history, mode of delivery, and duration of labor, were compared between women with and those without PUR. Results Of the 771 participants recruited, 84 (10. 9%) had PUR: 82 (10.6%) with covert PUR and 2 (0.3%) with overt PUR. Women with instrumental delivery were more prone to develop PUR ( P = 0.03), with an odds ratio (OR) of 1.194 (95% confidence interval [CI], 0.56–1.90). A duration of labor of more than 700 minutes was a good predictor of PUR. The area under the receiver operating characteristic (ROC) curve was 0.634 (95% CI, 0.567–0.702; P < 0.001), with an OR of 1.003 (95% CI, 1.001–1.004). Conclusion Covert retention of urine was significantly associated with parturients who had an instrumental delivery and a duration of labor of more than 700 minutes.

Effects of postoperative analgesia on postpartum urinary retention in women undergoing cesarean delivery

Various analgesics and administration methods are used to provide women undergoing cesarean delivery pain relief after surgery. We compared three methods of postoperative analgesia regarding the incidence of postpartum urinary retention (PUR) in primiparous women undergoing elective cesarean delivery. We estimated post-void residual bladder volume after the first postpartum micturition among 150 parturient women. Risk factors stratified for PUR defined by 150-mL post-void residual bladder volume were analyzed. Obstetric parameters and prevalence of lower urinary tract symptoms after surgery were compared among three groups of parturient women given different postoperative analgesia: epidural bolus morphine (EBM), patient-controlled epidural analgesia (PCEA) with ropivacaine-fentanyl, and intramuscular pethidine. The incidence of PUR was higher in the group given EBM (33.3%) than the groups receiving ropivacaine-fentanyl by PCEA (15%) or intramuscular pethidine (16.7%) (P = 0.038). Eighteen (12%) parturient women needed bladder catheterization to resolve their urinary retention at 1 day postpartum but all achieved spontaneous micturition prior to hospital discharge. The need for catheterization was also increased in the group with EBM (21.7%) in comparison with the other two groups (6.7% and 3.3%, respectively, P = 0.011). At the 3-month follow up, six women (4%) had obstructive voiding problems and seven women (4.7%) had irritating voiding problems. At the 1-year follow up, only one woman in the EBM group had incomplete emptying and another in the PCEA group had urinary incontinence. Epidural analgesia with morphine was significantly associated with post-cesarean urinary retention. Nonetheless, it was not detrimental to later urinary function.

Urodynamic findings in women with pelvic organ prolapse and obstructive voiding symptoms

Objective To determine whether obstructive voiding symptoms in women with advanced pelvic organ prolapse (POP) were associated with objective bladder outflow tract obstruction. Methods We reviewed preoperative data from patients with advanced POP who underwent surgical correction at the Department of Obstetrics and Gynecology, Carmel Medical Center, Haifa, Israel, between December 1, 2005, and November 30, 2007. Obstructive voiding symptoms were recorded from Pelvic Floor Distress Inventory-20 questionnaires. Results Of the 81 women aged 44–80 years who were included in the study, 40 (49.4%) reported incomplete bladder emptying preoperatively. There was no significant difference between these women and asymptomatic women in terms of demographic and clinical parameters such as age, parity, and stage of prolapse. Furthermore, there was no significant difference with regard to postvoid residual bladder volume (52.8 ± 65.8 vs 41.6 ± 41.2 mL), maximal (23.8 ± 11 vs 21.9 ± 9.6 mL/second) and average (10.3 ± 6.2 vs 9.3 ± 4 mL/second) urinary flow velocities, prevalence of increased postvoid residual volume (10.0% vs 4.8%), or obstructive urinary flow (17.5% vs 7.3%). Conclusion Almost half of all women with advanced POP experienced incomplete bladder emptying; however, this symptom did not correlate with objective urodynamic bladder outflow tract obstruction.

Recurrent postpartum urinary retention: A case report

Postpartum urinary retention (PUR) is a clinical condition that is neither well-recognized nor defined by standardized means but normally has a good prognosis. We present the case of a woman with a history of PUR who demonstrated recurrent PUR. Prolonged first and second stage of labor, isolated prolonged second stage of labor, forceps delivery or vacuum extraction, perineal laceration, nulliparity and epidural anesthesia can act as independent risk factors for the development of PUR. In this case, epidural anesthesia, which was administered in both deliveries, was the only risk factor, suggesting that its application in a woman with a history of PUR should be carefully considered and discussed with the patient. Bladder drainage resolves PUR, after which there seems to be no cumulative risk for voiding dysfunction. An initial smaller post-void residual bladder volume may have a predictive value concerning the time to resolution of PUR.

Postpartum Urinary Retention After Cesarean Delivery

Liang, C.C.; Chang, S.D.; Chang, Y.L.; Chen, S.H.; Chueh, H.Y.; Cheng, P.J. Author Information

Postpartum Urinary Retention After Cesarean Delivery

Reported rates of postpartum urinary retention (PUR) following vaginal delivery range as high as 18%, but the risk of PUR associated with cesarean delivery is difficult to determine because of the effects of surgery and anesthesia on postpartum bladder function and also because there is no consensus on what constitutes PUR. In this study, PUR was diagnosed when ultrasonography demonstrated a postvoid residual bladder volume (PVRBV) of 150 mL or greater. Participating in this prospective study were 605 pregnant women having cesarean section. The PVRBV was estimated ultrasonically after first micturition. The overall incidence of PUR following cesarean delivery was 24.1%. The incidence of overt PUR, when no spontaneous micturition took place 6 hours after removal of the catheter and patients developed symptoms of obstructed voiding such as incomplete emptying, straining, and difficulty voiding, was 7.4%. Covert PR, with no associated urinary symptoms despite an elevated PVRBV, was more than twice as frequent (16.7%). Factors significantly associated with PUR included postoperative epidural morphine administration, multiple pregnancy, and a low body mass index at the time of delivery. After 3 months of follow-up, 5% of patients had obstructive voiding symptoms and 9.1% had irritative voiding symptoms. Differences in the frequency of voiding problems between the PUR and normal groups were not statistically significant. Nearly one-fourth of these patients developed PUR following cesarean delivery. The chief contributing factor was the use of morphine for postoperative analgesia. When transient and diagnosed at an early stage, PUR did not compromise urinary function and was not associated with subsequent voiding problems.

The prevalence of silent postpartum retention of urine in a heterogenous cohort

SummaryThe aim of this study was to assess the prevalence of silent postpartum retention of urine. It included 100 patients within 48 h from delivery or removal of indwelling catheters, when such catheters were inserted during labour. Residual urine was estimated using a portable bladder scan. A total of 37 patients (37%) had a post void residual bladder volume > 150 ml; the volume was between 151–200 ml in 26 patients (26%) and > 200 ml in 11 patients (11%). No association was found with time since delivery, or catheter removal in those catheterised at the time of delivery, catheterisation at the time of delivery, use of regional anaesthesia, or mode of delivery. This showed that silent retention of urine affects a significant proportion of various groups of patients after delivery, which calls for further research into this area.

Prevalence and associated risk factors of retention of urine after caesarean section

Caesarean section poses higher risk of postpartum urinary retention (PUR) than vaginal delivery. The aim of this study was to identify the prevalence and the associated risk factors of PUR after caesarean section. Two hundred seven parturients (mean age = 31.26 years old, median parity = 0) who delivered by caesarean section were recruited from the postnatal unit of a tertiary hospital in Hong Kong. Voiding was encouraged 6 h after removal of Foley catheters. Transvaginal ultrasound scan was performed immediately after voiding to estimate the postvoid residual bladder volume (PVR). PUR after caesarean section was defined as PVR of more than 150 ml. The results indicated a prevalence of 3.38%. Logistic regression analysis indicating 'lack of progress of labor' was the only significant associated factor (p < 0.001). The findings of this study provide information for further exploration on how to reduce the morbidity caused by PUR in the postoperative period of caesarean section.

Assessing intra-fractional bladder motion using cine-MRI as initial methodology for Predictive Organ Localization (POLO) in radiotherapy for bladder cancer

Aim To assess the feasibility of using cine-MR to study intra-fractional time–volume and volume-deformity patterns of the bladder during radiotherapy as initial methodology for Predictive Organ Localization (POLO). Methods Nine patients receiving radiotherapy for localized muscle invasive bladder cancer were prospectively studied. Each had an MR scan performed on an empty bladder using a T1 weighted cine sequence over a period of 20 min. Scans were taken prior to, and repeated towards the end of, radiotherapy treatment. Time–volume sequences were determined and compared before and during radiotherapy. Absolute bladder volumes were then correlated with changes in bladder wall position. Results The mean post void residual bladder volume prior to radiotherapy at time 0 was 113 cm 3 [SD 53] and this did not differ significantly during radiotherapy −106 cm [SD 40] ( p = 0.24, paired t-test analysis). A linear relationship was observed for the rate bladder filling over a 20 min period, which did not significantly change on the cine-MR during radiotherapy (regression coefficient 2.1 vs 1.6, respectively, p = 0.51). Significant positive relationships were seen between volume and anterior ( p = 0.02), superior ( p < 0.001), and inferior ( p = 0.03) wall motion. These relationships were complex, though linearity was observed for volumes up to 150 cm 3. The 1.5 cm CTV–PTV margin was sufficient to account for expansion in the majority of cases with the only breach occurring on the anterior wall in one patient. Conclusions This study confirms the feasibility of using cine-MR for POLO. The development of such predictive methodology may compensate for the need to use an isotropic CTV–PTV margin to simply cover bladder filling when using image-guided radiotherapy.

Physiologic Reactivity to a Laboratory Stress Task Among Men with Benign Prostatic Hyperplasia

The sympathetic nervous system and hypothalamic-pituitary-gonadal axis are involved in the pathophysiology of benign prostatic hyperplasia (BPH). The sympathetic nervous system and hypothalamic-pituitary-gonadal axis are also highly reactive to psychological stressors, yet associations between prostate function and reactivity to a psychological stressor have not been examined using standardized psychological stress paradigms. The objective of this study was to examine the associations between psychological stress reactivity and BPH disease parameters. A total of 83 men diagnosed with BPH completed a standardized laboratory stress task, yielding measures of blood pressure, testosterone, and cortisol reactivity. Links were examined between stress reactivity (as indicated by changes in blood pressure, testosterone, and cortisol during the stress task) and measures of BPH disease, including prostate volume, postvoid residual bladder volume, urine flow rate, self-reported lower urinary tract symptoms, and impact and bother scores. In equations controlling for BPH medications, body mass index, and age, greater diastolic blood pressure reactivity was associated with a greater transition zone volume (P <0.001), greater total prostate gland volume (P <0.05), greater postvoid residual bladder volume (P <0.05), more severe lower urinary tract symptoms (P <0.001), and greater impact scores (P <0.05). Greater cortisol reactivity was associated with greater bother (P <0.05) and impact (P <0.001) scores. Physiologic reactivity to a standardized laboratory stressor is associated with objective and subjective BPH disease parameters. These findings contribute to growing data suggesting that stress conditions could be associated with the development or aggravation of prostatic disease.

Postpartum urinary retention after cesarean delivery

Objective: To investigate the incidence of postpartum urinary retention (PUR) after cesarean delivery and determine which obstetric factors contribute to this problem. Method: A prospective study recruited 605 pregnant women who had a cesarean delivery. Each patient’s postvoid residual bladder volume (PVRBV) was estimated with an ultrasound scan after first micturition. The women were divided into 2 groups: PUR (PVRBV ≥ 150 mL) and normal. Patients’ characteristics, obstetric parameters, and prevalence of lower urinary tract symptoms at 3 months postpartum were compared. Result: The overall incidence of PUR was 24.1%. The incidence of overt and covert PUR was 7.4% and 16.7%, respectively. Morphine-related postoperative analgesia, multiple pregnancy, and low body mass index were significantly associated with PUR. At 3-month follow-up, 5.0% of patients had obstructive voiding symptoms and 9.1% had irritative voiding symptoms. Conclusion: Our results revealed PUR was a common phenomenon in patients who had a cesarean delivery, and morphine-related postoperative analgesia was the main contributing factor.

99mTc-MAG3 Renography: Normal Values for MAG3 Clearance and Curve Parameters, Excretory Parameters, and Residual Urine Volume

Specific quantitative measurements have been recommended to assist in the interpretation of technetium-99m mercaptoacetyltriglycine (MAG3) renal studies. Our objective was to define the sex- and age-specific normal ranges for these recommended parameters. Data were obtained from a retrospective analysis of 106 subjects who were evaluated for kidney donation. The MAG3 clearance was calculated using a common camera-based method. The relative uptake, prevoid/postvoid and postvoid/maximum count ratios were determined using whole-kidney regions of interest (ROIs). Time to peak, time to half-peak, 20 min/maximum and 20 min/2-3 min count ratios were determined for cortical and whole-kidney ROIs. Residual urine volume was calculated on the basis of the pre- and postvoid bladder counts and voided urine volume. The mean camera-based MAG3 clearance was 321 +/- 69 mL/min/1.73 m2, essentially the same as the mean plasma sample MAG3 clearance in comparable populations. The percentages of relative uptake in the right and left kidneys were 49% and 51% +/- 4%, respectively; no difference was seen between men and women. Cortical values were lower than the whole-kidney values (p < 0.001); the mean cortical 20 min/maximum count ratio was 0.19 (SD, 0.07 and 0.04 for right and left kidneys, respectively). The mean postvoid/maximum whole-kidney count ratio was < 0.1, and the mean postvoid residual bladder volume was < 30 mL. Normal limits adjusted for age and sex have been established. Applying normal ranges to quantitative MAG3 parameters may assist in the interpretation of MAG3 scintigraphy and facilitate appropriate patient management.