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Radionuclide renal scan performed with (diethyle triamine penta acetic acid (DTPA), ethylene dicysteine (EC), mercaptoacetyltriglycine (MAG3), and dimercaptosuccinic acid (DMSA) provides split function between the two kidneys. Hence it is a valuable method to evaluate percentage function prior to nephrectomy. Nephrectomy may be done in a prospective renal donor or it may be done for a diseased kidney. In either case, the nephrologist/ urologist must ensure that the remaining kidney is able to sustain renal function post nephrectomy. We present a case where conventional renal scan had underestimated the split function due to a large posterior cortex cyst accounting for attenuation of radionuclide photons. Repeat scan in anterior view had eliminated this erroneous result. We could not find any such reported discrepancy despite extensive web-based search. World J Nephrol Urol. 2021;10(1):12-14 doi: https://doi.org/10.14740/wjnu422

BACKGROUND: One of the basic clinical indications for dynamic renal scintigraphy (DRS) is a diagnosis of obstructive uropathy and/or nephropathy. Currently, a basic quantitative criterion for diagnosing nephropathy is the percentage of individual kidney’s contribution in the global uptake of a radiopharmaceutical from the blood (so-called Split Function - SF). From a clinical point of view, a parameter evaluating a radiopharmaceutical uptake and reflecting the efficiency of a specific kidney, determined independently of the total uptake of both kidneys, would be much more useful. Based on a Rutland theory, a kidney uptake constant K proportional to a radiotracer uptake by individual kidney was introduced and applied to DRS with 99mTc-ethylene-1-dicysteine (99mTc-EC). In addition, a kidney efficiency index (KEi) was also worked out as a new parameter obtained by dividing the uptake constant K by the surface of the ROI of a given kidney, which can be interpreted as the average “efficiency” of clearance of a kidney. MATERIAL AND METHODS: K and KEi values were verified in 72 studies selected retrospectively from patients referred routinely for DRS, with available current level of blood creatinine, used for calculation of estimated GFR (eGFR) according to a CKD-EPI formula. After splitting of eGFR values into individual kidneys according to SF, single kidney eGFR values (SKeGFR) were obtained and then used as a verification method for SF, K and KEi values. RESULTS: Correlation between SF and SKeGFR values, rsp = 0.64, was significantly weaker (p < 0.0022) than the correlation of SKeGFR values with K uptake constants and KEi indices: 0.90 and 0.84, respectively. CONCLUSIONS: Uptake constant K and KEi, as quantitative parameters, give the opportunity to analyze a function of each kidney separately and in an absolute way. KEi also allows for a reliable assessment of kidneys of atypical sizes (larger or smaller than average). It also gives the opportunity to create normative values for this parameter and may be useful in a number of clinical situations where the diagnostic effectiveness of such a relative parameter as SF, is severely limited, e.g. in assessing a large kidney with hydronephrosis or while differing a cirrhotic from hypoplastic (i.e. a small but properly functioning) kidney.

INTRODUCTION AND OBJECTIVE:MAG3 nuclear renograms are standard practice to document split renal function in patients with possible ureteropelvic junction (UPJ) obstruction. We hypothesized that qua...

Pelvic ureteric junction obstruction (PUJO) can pose a management challenge to urologists. The natural history of the disease, particularly in adults is poorly understood and management decisions are largely based on historical, poor quality data. Additionally, many older patients may already have a degree of renal impairment secondary to systemic disease, further compounding the situation. The purpose of this paper is to detail the pathophysiology and natural history of PUJO, discuss the implications of chronic kidney disease in this population detailing the current evidence base for poorer functioning kidneys and describe the nephrological advantages of accurate renal function testing. There exists accurate methods to assess both glomerular filtration rate (GFR) and split function which could potentially provide both the urologist and patient with more relevant data on which to base their decisions when contemplating surgical intervention. The existing, low patient number case series currently published fail to address the relevance of overall GFR on the outcomes after pyeloplasty, no studies use single unit GFR and there is no clear consensus on what constitutes surgical success. PUJO is an area of benign upper tract disease that is in need of high-quality scientific studies to identify when intervention is necessary, long-term success of both surgery and conservative management in poorer functioning kidneys and clear guidelines for urologists.

This study evaluates the usefulness of parameters allowing assessment of renal function in absolute values in dynamic renal scintigraphy (DRS) with 99mTc-ethylenedicysteine (99mTc-EC) uptake constant (K), mean transit time (MTT), and parenchymal transit time (PTT) in the diagnosis of obstructive uro/nephropathy. The study included 226 people: 20 healthy volunteers, for whom normative values of assessed parameters were determined, and 206 patients. Reproducibility of results obtained by two independent operators, specificity, correlation with estimated GFR (eGFR), and Cohen’s kappa were used to evaluate reliability of assessed parameters. Normative values were as follows: K ≥ 1.6, MTT ≤ 250 s, and PTT ≤ 225 s. Reproducibility of determination of K (rs = 0.99) and MTT (rs = 0.98) was significantly higher than that of PTT (rs = 0.95) (p = 0.001). Specificity was 100% for K, 81% for MTT, and 91% for PTT. Correlation of eGFR with K (rs = 0.89) was significantly higher than with PTT (rs = 0.53) and with split function (SF) (rs = 0.66) (p &lt, 0.0001). Cohen’s kappa was κ = 0.89 for K, κ = 0.88 for MTT, and κ = 0.77 for PTT. In a group of patients where standard DRS parameters are unreliable (bilateral obstructive uro/nephropathy or single functioning kidney), the use of K (the most effective among assessed parameters) changed the classification of 23/79 kidneys (29%). K enables reproducible assessment of absolute, individual kidney function without modifying routine DRS protocol. Diagnostic value of MTT and PTT is limited.

Leukemia – a type of blood cancer which was caused by abnormal growth of White Blood Cells (WBC) in bone marrow. Accurate identification of effected patients and diagnosing within time is most important otherwise it causes to death. Machine learning algorithms are most popular for accurate identification of patient status. Presenting 152 patients data which was clinically collected. In this paper, proposing Bagging with Random split function for classification of leukemia patients. Also compared the classifier performance with various ensemble techniques – Multiclass classifier, Logit Boost, Stacking and Random Committee classifiers. Experiments are conducted and proven that bagging with Random split function shows 95% accuracy on classification of leukemia disease dataset.

BACKGROUND: Output efficiency (OE) and normalized residual activity (NORA) are two parameters that allow quantifying the renal drainage at any moment of renographic acquisition. Although OE is theoretically more accurate than NORA in case of a decreased overall renal function, both parameters present some weaknesses. OBJECTIVES: To compare both parameters and to evaluate whether the clinical information provided by both parameters is identical. METHODS: From a large database of Tc-99m mercaptoacetyltriglycine 3 renographic studies, 450 kidneys were selected covering a large range of ages, overall function, split function, and quality of drainage. NORA and OE were calculated at the end of the 20-min renogram, as well as on the late post erect postmicturition (PM) views. RESULTS: An inverse correlation was observed between NORA 20 and OE 20 (r=-0.926), as well as between NORA PM and OE PM (r=-0.936). Discrepancies were noted in approximately 10% of the kidneys, but main discrepancies, which would result in a different estimation of the quality of drainage, were only observed in 2% of the kidneys. There was no bias in the discordances; OE could reveal a better as well as a worse quality of drainage than NORA. It is likely therefore that imperfections of both parameters might be the cause of the divergences. The stratification of the kidneys according to age, overall renal function, split function, or quality of drainage did not modify the results. CONCLUSION: NORA, being much easier to program, can replace the output efficiency in the evaluation of renal drainage. © 2011 Wolters Kluwer Health

ObjectiveTo evaluate a mentoring circle workforce development intervention among a group of public health nutrition novices.DesignThe mentoring circle intervention focused on facilitating practice-based public health nutrition competence development and supporting reorientation of practice from clinical services to preventive services. A retrospective post-intervention qualitative semi-structured interview was used to explore the experiences of those participating in the mentoring circle and to make evaluative judgements about intervention attributes and effectiveness.SettingVictoria, Australia.SubjectsThirty-two novice public health nutrition practitioners employed in the state public health system.ResultsKey evaluative theme categories relating to the mentoring circle intervention were identified, including the structure and function of the group, the utility of using advanced-level competency items to guide planning, having a safe and supportive environment for learning and the utility of learning via mentoring and on-the-job experiences. These qualitative evaluation data identify the attributes of the mentoring circle intervention contributing to intervention effectiveness.ConclusionsThis qualitative evaluation indicates that mentoring circles can be an effective workforce capacity-building intervention, particularly in novice workforces characterised by professional isolation and split function roles.

PURPOSE The split or differential renal function is the most widely accepted quantitative parameter derived from radionuclide renography. To examine the intercenter variance of this parameter, we designed a worldwide round robin test. METHODS Five selected dynamic renal studies have been distributed all over the world by e-mail. Three of these studies are anonymized patient data acquired using the EANM standardized protocol and two studies are phantom studies. In a simple form, individual participants were asked to measure renal split function as well as to provide additional information such as data analysis software, positioning of background region of interest, or the method of calculation. RESULTS We received the evaluation forms from 34 centers located in 21 countries. The analysis of the round robin test yielded an overall z-score of 0.3 (a z-score below 1 reflecting a good result). However, the z-scores from several centers were unacceptably high, with values greater than 3. In particular, the studies with impaired renal function showed a wide variance. CONCLUSION A wide variance in the split renal function was found in patients with impaired kidney function. This study indicates the ultimate importance of quality control and standardization of the measurement of the split renal function. It is especially important with respect to the commonly accepted threshold for significant change in split renal function by 10%.

Functional compensation occurs in a kidney when the function of the contralateral kidney is decreased or absent. What is, however, not documented is the level of unilateral renal impairment at which functional compensation occurs. Split function, as obtained from a radionuclide renogram, can only show the asymmetry between both kidneys. The aim of the present work was to evaluate at what level of unilateral impairment a functional compensation can be observed in the contralateral normal kidney. From a large database, 180 children over 2 years of age with unilateral pathology were retrospectively selected. All of them underwent a radionuclide study, combining a technetium-99m mercaptoacetyltriglycine (Tc-99m MAG3) renogram associated with a chromium-51 ethylenediaminetetraacetic acid (Cr-51 EDTA) overall clearance, allowing a precise estimation of single-kidney glomerular filtration rate (SKGFR). Below 30-35 ml/min/1.73 m2, there was a significant inverse correlation between SKGFR on the normal and the abnormal side. Above this level, no such correlation was observed, the mean SKGFR on the normal side remaining around 58 ml/min/1.73 m2, whatever the value of SKGFR on the abnormal side. In pediatric patients, hyperfunction occurs when SKGFR of the diseased kidney is below 30-35 ml/min/1.73 m2.

Purpose: Retrospective evaluation of operative techniques and perioperative management as related to the primary anatomical and functional situation as well as analysis of the preliminary postoperative results regarding kidney function, continence and complications. Materials and Methods: From October 1992 to April 2003, 21 patients with bladder exstrophy-epispadias complex were treated, consisting of 12 children with untreated exstrophy and 9 who had undergone unsuccessful previous operations. Single-stage complete repair using the Erlangen concept was done during the first weeks of life in 8 infants and before school age in 3 children. One 13 year old girl had received a primary Mainz pouch II. The 9 unsuccessfully operated patients required a variety of different operations. The mean follow-up of 17 regularly controlled children was 62 months (range 3 to 129 months). Results: In all children global kidney function remained stable, while reflux or obstruction was responsible for impaired unilateral split function ranging between 31% and 45% in 5. Four children were continent day and night after complete single-stage repair, 4 after ureterosigmoidostomy or Mainz pouch II and 5 after augmentation. Conclusions: In the newborn with previously untreated exstrophy-epispadias, we recommend single-stage complete functional reconstruction within the first weeks of life. Continence without loss of kidney function can be achieved in 50% of these children. If adequate bladder capacity and continence cannot be achieved, an augmentation procedure or Mainz pouch II is our method of choice.

Objective Ultrasonography (US) is commonly used to visualize the upper urinary tract in children and adolescents with meningomyelocele (MMC). The aim of this investigation was to prospectively evaluate US in those with spinal angulation or obesity and compare it to the corresponding results obtained by mercaptoacetyltriglycine renography. Patients and methods Twenty-five children and adolescents with MMC and pronounced angulation of the spine or obesity, were prospectively investigated with both US and renography during the period 2006 to 2008. Results In 13 (52%) patients the kidneys could not be fully evaluated; in 4 (16%) neither renal size nor pelvic dilation, in 12 (48%) renal length and in 5 (20%) dilation was not accessible. In 23 individuals where dilatation could be evaluated uni- or bilaterally, US was compared to OEE% (%outflow excretion efficiency) at renography. In 1 of these individuals there was normal OEE% while slight dilatation on US was noticed. In 2/15 individuals, split function at renography did not correlate with renal length on US. Conclusion Severe spinal angulation and obesity in individuals with MMC reduced the possibility to evaluate the urinary tract by US. However, it seems that renography could be a reliable alternative to evaluate renal condition in those patients where US is insufficient.

We report a case of a 37-year-old man with a body mass index of 28 kg/m(2) who presented to our outpatient clinic with intermittent left flank pain. Non-contrast abdominopelvic computed tomography revealed a giant coralliform calculus in the left kidney. This giant kidney stone was successfully treated with 3 sessions of percutaneous nephrolithotomy (PNL) with a total 12 accesses. There was no significant reduction in the split function of the kidney after PNL.

Summary Background: Reference values for 99mTc-MAG3 renography were determined and the influence of sex and age (41%, Tmax

A suitable candidate for kidney donation is usually seen 1–3 months before the date of surgery. He is assessed by Nephrologists, Urological Surgeons and Anesthetists, by thorough investigations with the aim of avoiding surgery for any person who is ASA 3 or above. Moreover, although we haven’t faced obese candidates in our experience, we think that a BMI above 35 should be considered a relative contraindication for kidney donation since those subjects would be more exposed to perioperative complications and late renal dysfunction.

the right kidney can be determined both for the anterior and the posterior projection, allowing calculation of its geometric mean. The same can be done for the standard placed at the level of the left kidney using the first and the third acquisitions. As the same standard is used for the right and for the left kidney, if the attenuation is equal, the ratio of the geometric mean of the standard at these two locations is one. The ratio of the calculated geometric mean will differ from unity because of bone attenuation and differences in body thickness at the levels of the right and the left kidney. This calculated value can then be used to correct the geometric mean of the differential renal function calculated from the first data acquisition. The same approach can be used in renography to estimate renal split function in the presence of a pelvic kidney.

Objective. Significant controversy remains concerning the best way to treat ureteropelvic junction obstruction (UPJO). This study evaluates subjective and objective outcomes of retrograde holmium laser endopyelotomy in a selected population with UPJO. Material and methods. Forty-seven patients with UPJO were referred to retrograde endopyelotomy between April 2004 and March 2007. Patients with a very large pelvis, a high insertion of the ureter, a renal split function below 20% or a long (>2 cm) stenosed ureteropelvic segment, and patients younger than 18 years were not selected for endopyelotomy, but subjected to laparoscopic pyeloplasty. Renal function was estimated on renal diuretic scan before and after surgery with a mean renographic follow-up of 35 weeks. Subjective results were based on questionnaires which were returned from 44 patients with primary (n=37) or secondary (n=7) obstruction (mean follow-up 110 weeks). Success criteria were defined as symptom relief and improved or preserved renal function. Results. Twenty-nine patients (66%) experienced complete symptom resolution and 10 patients (23%) had significant symptom improvement (i.e. no need for pain-killing medication). Five patients (11%) had unchanged symptoms. No difference in postoperative renal function was observed between these three groups of patients. The differences between preoperative and postoperative renal function were non-significant in each group. No major complications were observed. Five patients (11%) were referred to retreatment owing to unchanged symptoms. Conclusion. Retrograde ureteroscopic endopyelotomy is a safe and effective treatment option in patients with primary and secondary UPJO when selected properly.

The split function (SF) of hydronephrotic kidneys may dramatically decrease in the presence of severe and persistent obstruction, necessitating surgical correction. The indication for pyeloplasty versus nephrectomy is mainly based on the results of repeated renal ultrasonography (US) and MAG3-diuretic nephrography (DNG) with SF. Nephrectomy is usually recommended if SF is less than 10 %. However, recent studies with long-term follow-up indicate that even with an initial SF of10 %, a significant improvement of SF may be seen when pyeloplasty is performed so that nephrectomy may not be justified.Case histories of 32 children with pre- or postnatally diagnosed severe hydronephrosis were retrospectively analyzed. Surgical correction was indicated if US revealed progredient hydronephrosis (anteroposterior diameter20 mm) and/or DNG demonstrated a loss of SF40 % and/or severe obstruction, respectively. Postoperative follow-up examinations included renal US after 3, 6 and 12 months, as well as DNG after 12 months.Thirty-two children (25 male, 7 female) underwent Anderson-Hynes pyeloplasty (AHP). At the time of operation, the mean age of the patients was 33 months (1 - 156 months). Patients were divided into 3 groups according to the initial SF: group I, 21 patients with SF40 %; group II, 7 patients with moderately impaired SF between 10 - 40 %; group III, 4 patients (aged 1 - 137 months) with a SF of10 %. In 2 patients, percutaneous nephrostomy (PCN) was performed, followed by AHP. Thirty patients underwent AHP without preceding PCN. In group III, SF increased from10 % preoperatively to 21 %, 27 %, 45 %, and 53 % postoperatively, respectively. In all patients, postoperative DNG demonstrated a significant improvement of SF from 41 %, on average, preoperatively (range 0 - 64 %) to 47 %, on average, postoperatively (range 17 - 60 %).Long-term follow-up confirms that the prognosis for renal function is excellent in patients with moderately reduced SF. The significant improvement of SF 12 months after AHP in all patients with a poor SF of less than 10 % supports our approach of performing pyeloplasty in patients even with an initial SF of10 %, which is in contrast to common practice.

Summary Objective: A drop of split renal function often constitutes a criterion for pyeloplasty in hydronephrosis since it is considered as representing deterioration of the affected kidney. The aim of this work was to determine, in a selected population of patients with a drop of split function of at least 5%, if the evolution of single kidney glomerular filtration rate (SKGFR) was parallel to the one of split renal function. Methods: From a large data basis, we found retrospectively only 29 children (10 below and 19 above two years of age at first examination) having had at least two Tc-99m mertiatide (Tc-99m MAG3) renographic explorations for various urological diseases, with a decrease of split function of at least 5% between the two examinations. Evolution of split function was compared to evolution of SKGFR obtained by means of the combination of Tc-99m MAG3 split function and overall glomerular filtration rate as given by the chromium Cr 51 ethylenediamine tetraacetic acid (EDTA) clearance. Results: For the group above two years of age, SKGFR increased or remained stable in 63% of the cases, while in the children less than 2 years of age, a decrease of SKGFR was never observed, according to the maturation of overall GFR in this age group. Thus, the decrease of split function was not necessarily associated with a similar decrease of SKGFR. Conclusion: In patients with unilateral or bilateral urological disorders, deterioration of split renal function does not necessary correspond to a loss of function of the affected kidney. SKGFR often modifies the interpretation of split function.

We investigated the outcome of patients with antenatally detected pelviureteric junction (PUJ) obstruction treated either conservatively or surgically. The series comprised 68 such patients, 54 with unilateral obstruction. Of the unilateral cases, 22 units were treated conservatively, 21 underwent early and 11 late surgery. Of the bilateral cases, 18 units were treated conservatively, 9 underwent early pyeloplasty, whereas 1 underwent later surgery. Among the conservatively treated unilateral cases, none of the patients’ good renal function deteriorated during follow-up. In the group with early surgery, the primary good function remained unchanged in all. In some patients, moderate function improved after early pyeloplasty, but in patients with poor function no improvement occurred. Of patients who underwent late pyeloplasty, primary good renal function remained unchanged in all except 1, although it had deteriorated to moderate function in some before surgery. In all except 1 patient with bilateral obstruction treated conservatively, both the grade of hydronephrosis and split function remained unchanged. In most patients the outcome of antenatally detected unilateral PUJ obstruction with initially good renal function, whether treated conservatively or surgically, seems favorable. Some patients with moderate function might benefit from pyeloplasty. In kidneys with poor function, recovery may be minimal despite pyeloplasty.

Radionuclide methods are important diagnostic modalities for the detection and quantification of renal disease. There are three categories of renal radionuclide investigations: Clearance studies Split function investigations with measurement of parenchymal uptake, parenchymal wash-out, and pelvic and ureteric urinary flow (renography) Renal imaging (scintigraphy)

Summary— A total of 49 retrograde balloon dilatations for pelviureteric junction (PUJ) obstruction were carried out on 43 pelviureteric junctions in 42 patients from 1986 to 1991. The majority (34/ 43) were performed as primary treatment for PUJ obstruction, with 9 patients having a history of previous open pyeloplasty. Follow-up ranged from 3 months to 4 years (mean 18 months). Clinical improvement, as assessed by absence of symptoms, was seen in 34 cases (80%). There was either no change or an improvement in renographic findings (t1/2 time and/or split function) in 40 patients (93%). Of the 9 patients who were undergoing secondary treatment, 5 showed clinical improvement and 8 showed no change or renographic improvement. Nine patients required 12 further procedures, of which 5 were interval nephrectomy. Balloon pyelolysis is a simple procedure with good results over a 4-year follow-up period. It is less effective for the treatment of secondary pelviureteric junction obstruction. It has a low morbidity and no mortality, involves a short hospital stay and allows an immediate return to full activity. It is therefore an attractive alternative to open pyeloplasty as first-line treatment for PUJ obstruction.

Hepatobiliary scintigraphy (HBS) is a well established non invasive procedure for the differential diagnosis of intra-and extrahepatic jaundice. Clinical impact of hepatobiliary scintigraphy increased since the introduction of the 99mTc labeled hepatobiliary imaging agents by Loberg and coworkers in 1975 [16, 31].

Presented herein are initial experiences with the RP/ED renogram, a unique radioisotope differential split function study, which can be performed with a minimum of discomfort to the patient. This test should totally supplant the existing renogram and, with additional experience, may replace the use of split function studies in the evaluation of renovascular hypertension.

The suitability of the background-subtracted renogram as a method for separate kidney function in children was evaluated by comparison with planimetry of the individual renal parenchymal area measured from urography. In different groups of renal disorders the total kidney function as reflected by the glomerular filtration rate has been compared with the sum of right and left renal parenchymal areas. The percentage side distribution of kidney function estimated from the renogram combined with measurements of total glomerular filtration rate has been correlated to individual renal parenchymal area. A good correlation was found for both total and separate measurements. A moderate scatter around the regression lines has to be taken into consideration when kidney function is judged from planimetry. A highly significant correlation was observed between renography and planimetry for the percentage distribution of kidney function, indicating that both methods are well suited for determining the side distribution of kidney function. For calculation of individual kidney function, combination of renography and 51Cr-EDTA-clearance offers a reliable method with a modest dose of irradiation.

A quantitative renal scintillation camera study has been described for the evaluation of total renal function and the split function of the two kidneys by a noninvasive technic. It requires no patient preparation, is not affected by bowel gas, and no allergic reactions have been reported. Six cases are reported to illustrate its usefulness with renal tumors, neurogenic bladders, pyelonephritis, nephrolithiasis, congenital anomalies, and renal insufficiency.

The pyelogram urea washout test (PUWT) was performed in 96 hypertensive patients who had sufficient clinical and laboratory data for meaningful retrospective analysis. Seventy-six patients had negative PUWTs. At least one other negative test (usually aortography) confirmed the negative washout test in each. Eleven patients had unilaterally positive tests and in 9 of these there was excellent correlation with split function studies, renal arteriography or results of surgery. In the remaining 2 there was no evidence of renovascular hypertension (false positives).Since there were no false negative tests, the PUWT seems to be well suited as one of the screening tests to exclude the diagnosis of hypertension due to surgically correctable unilateral renal disease. Because of the occasional false positive test, renovascular hypertension should be confirmed by aortography. Split function studies or other tests should be performed if aortography is negative because of the possibility of unilateral pyelonephritis.

A case of renal artery stenosis (RAS) is described in a seven-year-old boy. The pre-operative renal perfusion-excretion determination (RPED) was diagnostic of renal artery stenosis. In addition, after corrective surgery the postoperative RPED showed relatively normal values with a decrease in tubular transport time (TTT), an anticipated finding in patients with corrected RAS. This patient also represents an interesting example of intrarenal collateral vessel formation in an ischemic kidney.

Quantitative methods to measure the glomerular and tubular function of the kidneys with radionuclides have been available for many years. They have not been widely used because the techniques and the calculations exceeded the scope of routine nuclear medicine practice. Validation of simplified methods and the introduction of computer technology have made measurement of the effective renal plasma flow (ERPF) and the glomerular filtration rate (GFR) simple enough so that they can be performed reproducibly in most nuclear medicine departments. The estimation of ERPF with radioiodinated OIH and GFR with 99m TcDTPA can be achieved in many ways, all of which yield clinically useful results. How to get the best results using the simplest methods is still unclear. The required accuracy depends on the intended clinical use. Our preference at the present time is to use a single or double plasma sample to calculate global ERPF or GFR, and to use the 1–2 min OIH or 1–3 min Tc-DTPA uptake to calculate relative function of the two kidneys (split function ERPF or GFR). The choice of method will be influenced by local factors, such as the nature of the patient population, the case volume, and the resources available. A desirable goal for future studies is to document carefully the capabilities and limitations of each alternative method, so that the choice can be rational.

Single kidney function was determined both by single probe renography (131I hippuran) and gamma camera scintigraphy (99Tc111 DMSA) in the sitting position in 42 consecutive patients who were referred to renography as a part of the workup of their hypertension. the positioning of the detectors turned out to be satisfactory in 83 per cent of the patients when compared with the determination of the split function at scintigraphy. This might be explained by the small 100 per cent isocount area of the probe (avoiding the effect of mobile kidneys) and by the 4-channel localization system