Comparison of parameters of 123I-MIBG scintigraphy for predicting prognosis in patients with dilated cardiomyopathy.

123I-metaiodobenzylguanidine (MIBG) scintigraphy has been used to predict prognosis of patients with dilated cardiomyopathy (DCM), although it is unknown which parameter of MIBG is the most useful clinically. We studied MIBG in 59 patients with DCM, and followed them up to evaluate the prognosis of DCM. Single photon emission tomography (SPET) and planar imaging were performed, both early (e) and 4 h (delayed, d) post-injection. 201Tl (TL) SPET and radionuclide-ventriculography were also investigated. The total defect score of early and delayed MIBG and 201 Tl (MIBGeDS, MIBGdDS, TLDS) was analysed visually for each SPET image. The heart to mediastinum ratio (H/M) for both the early and delayed MIBG planar images and myocardial washout rate at 4 h were analysed quantitatively. Sixteen patients died during follow-up. Cox Hazards univariate analysis selected washout rate (P < 0.0001), H/Me (P = 0.0012), H/Md (P = 0.0001) and left ventricular ejection fraction (P = 0.0004) as indices for the prediction of cardiac death. Multivariate analysis selected washout rate as the most powerful independent predictor of prognosis (P < 0.0001). Survival curves with a threshold value of 52% for washout rate were able to differentiate a negative outcome from survival (P < 0.0001). TLDS, MIBGeDS and MIBGdDS were not useful in the prediction of prognosis. The washout rate of MIBG is the most potent predictor of cardiac death and is considered clinically useful.     

Volume expansion diuretic renal scan in urinary tract obstruction

The diuretic renal scan is used to differentiate the obstructed dilated urinary system from the nonobstructed dilated system. The technique, however, has a false-positive and indeterminate rate of 10%-15%. This usually is due to variables such as the degree of dilatation of the pelvicalyceal system or ureter, the degree of bladder distention, the diuretic dose, and the state of hydration. We developed the volume expansion diuretic renal scan (VEDRS) to overcome these variables and to improve the accuracy of the technique. Twelve patients who had obstructive patterns on the diuretic renal scan were evaluated. Ten patients were shown to be dilated but not obstructed. Two patients were confirmed as obstructed. This technique improves the accuracy of the diuretic renal scan.     

Evaluation of dilated upper renal tracts by technetium-99m ethylenedicysteine f+0 diuresis renography in infants and children

AIM: To evaluate the feasibility of modifying diuresis renography by the simultaneous administration of Tc-99m ethylenedicysteine and furosemide in the investigation of hydronephrosis and hydroureteronephrosis in infants and children. Parameters assessed were the diuretic response in normal kidneys and the ability of the F+0 study to differentiate between renal obstruction and nonobstruction. METHODS: One hundred and thirty-three children (93 males, 40 females; mean age 35.2 months) with sonographic diagnoses of hydronephrosis or hydroureteronephrosis underwent F+0 diuresis renography. Tc-99m ethylenedicysteine (3.7 MBq/kg body weight) and furosemide at an appropriate dose were administered intravenously at the start of the study. Posterior imaging of the kidneys and bladder was performed for 20 min followed by imaging after voiding. All patients were followed-up for 12 months, and the results of the initial F+0 diuresis renography were compared with the final diagnoses. Final diagnosis was based on the pediatric urologist's decision of either surgery or conservative management. RESULTS: A renal unit was defined as a kidney and its ureter. There were 262 renal units with 4 patients having a solitary kidney. 90 normal and 172 abnormal renal units on sonography were assessed by F+0 diuresis renography. The furosemide clearance half time for the 90 normal renal units was 5.8 +/- 1.4 min. Of the 172 abnormal renal units, 100 were classified as nonobstructed and 72 as obstructed on diuresis renography. All 100 nonobstructed renal units were correctly classified with no false-negative studies; of the 72 renal units classified as obstructed, there were 43 true-positive studies and 29 false-positive studies. The sensitivity was 100%, specificity was 78% and accuracy was 83%. CONCLUSION: Tc-99m ethylenedicysteine F+0 diuresis renography is a valid method for the investigation of hydronephrosis and hydroureteronephrosis in infants and children.     

Effectiveness of diuretic injection on the measurement of differential renal function using Tc-99m DMSA in patients with a dilated renal pelvis

AIM: The aim of this study was to evaluate the effectiveness of diuretic injection for the measurement of differential renal function (DRF) with technetium-99m dimercaptosuccinic acid (Tc-99m DMSA) scintigraphy in patients with a dilated pelvis. MATERIALS AND METHODS: A total of 46 patients who were referred for both technetium-99m-L,L-ethylenedicysteine (Tc-99m L,L-EC) and Tc-99m DMSA imaging and found to have a dilated collecting system on Tc-99m EC scintigraphy were studied. Four to 5 hours after intravenous injection of Tc-99m DMSA, imaging was performed in the supine position, and posterior, anterior, left and right lateral, and left and right posterior oblique views were taken. After this study, furosemide was administered intravenously and 30 minutes later, additional images in the anterior and posterior views were obtained. RESULTS: The kidneys were evaluated into 2 groups. Group 1 comprised 12 kidneys that had an obstructive curve pattern on Tc-99m EC scans. Group 2 comprised 34 kidneys that had a nonobstructive dilated renogram curve pattern. DRF of the kidneys in each patient were calculated, and the values obtained from the standard and diuretic DMSA scans were compared with each other for all patients and each group. Considering all the patients, the values of mean DRF on both standard and diuretic DMSA images were 55.4%+/-21.2% and 55.4%+/-21.5%, respectively. There were no significant differences between DRF values of each kidney obtained by the 2 methods. When we compared the DRF values in groups 1 and 2, there were again no significant differences. In group 1, the values of mean DRF on standard and diuretic images were 51.7%+/-13.7% and 51.6%+/-13.9%, respectively, and in group 2, the values of mean DRF were 56.7%+/-23.4% and 56.7%+/-23.6%, respectively. CONCLUSION: In view of our study, diuretic administration seems to be an unnecessary intervention because it has no effect on the accuracy of DRF measurements using DMSA scintigraphy in patients with a dilated collecting system whether it is obstructed or not.     

Consensus on renal cortical scintigraphy in children with urinary tract infection

A questionnaire related to cortical scintigraphy in children with urinary tract infection was submitted to 30 experts. A wide consensus was reached on several issues related to planar images: 99mTc dimercapto succinic acid (DMSA) appears as the most appropriate tracer for renal imaging; dynamic tracers are considered to be inferior, in particular 99mTc diethylenetriaminepentaacetate, which is not recommended. The general opinion is that DMSA scintigraphy is not feasible with a minimal dose below 15 MBq, whereas the maximum dose should not be higher than 110 MBq. The dose schedule generally is based on body surface area, and sedation is only exceptionally given to children. Images are obtained 2 to 3 hours after injection, preferably with high resolution collimators; pinhole images are used by only half of the experts. Posterior and posterior oblique views are used by most of the experts, and the posterior view is acquired in supine positions. At least 200.000 kcounts or 5 minute acquisition is required for nonzoomed images. As a quality control, experts check the presence of blurred or double outlines on the DMSA images. Color images are not used and experts report on film or directly on the computer screen. As far as normal DMSA images are concerned, most experts agree on several normal variants. Hydronephrosis is not a contraindication for DMSA scintigraphy but constitutes a pitfall. Differential renal function generally is measured, but no consensus is reached whether or not background should be subtracted. Most of the experts consider 45% as the lowest normal value. A consensus is reached on some scintigraphic aspects that are likely to improve and on some others that probably represent persistent sequelae. There is a wide consensus for the systematic use of DMSA scintigraphy for detection of renal sequelae, whereas only 58% of the experts are systematically performing this examination during the acute phase of infection.     

Technetium-99m-dimercaptosuccinic acid renal scintigraphy in children with urinary tract infections

The aim of this study was to determine the incidence of abnormal dimercaptosuccinic acid-Tc-99m ((99m)Tc-DMSA) renal scintigraphy findings in children with culture proved urinary tract infection (UTI) with or without vesicoureteral reflux (VUR). (99m)Tc-DMSA renal scintigraphy was performed in 343 children with culture documented UTI (247 girls and 96 boys) aged from three months to 14 years (middle age of 4.82 years). The children studied were all those submitted for renal scintiscan to the Institute of Nuclear Medicine, Military Medical Academy, Belgrade during a five-year period (2000-2004). Micturating cystoureterography (MCU) performed in all patients before (99m)Tc-DMSA scan, revealed VUR in 213 children, while in 130 children VUR was not detected by MCU. In 15 of the 213 children the grade of VUR was I, in 88 was II, in 57 was III, in 33 was IV and 20 children had grade V of VUR. Findings of (99m)Tc-DMSA renal scintigraphy were classified as: normal, equivocal and abnormal. Statistical analysis was performed using c(2)test. In all patients abnormal findings were detected in 38% (131/343), normal in 51% (174/343) and equivocal findings in 11% (38/343). In children with UTI and VUR the incidence of abnormal findings was 53% (112/213), of normal 37% (80/213) and of equivocal findings 10% (21/213). In children with UTI without VUR the incidence of abnormal findings was 15% (19/130), of normal findings 72% (94/130), and of equivocal findings 13% (17/130). The incidence of abnormal findings was significantly higher in children with UTI and VUR than in those with UTI without VUR (P<0.001). In children with VUR grades I, II, III, IV and V abnormal findings were 33%, 32%, 60%, 79% and 95% respectively. The incidence of abnormal findings was higher in children with VUR grades IV and V, than in grade I and II (P<0.001). Our results suggest that (99m)Tc-DMSA renal scintigraphy in children can discriminate between grade I-II and IV-V of VUR and also that in children with UTI and VUR abnormal findings in the scintiscan were more than three times higher than in children with UTI alone.     

Value of captopril renal scintigraphy in hypertensive patients with renal failure.

The aims of this study were to show the value of captopril renal scintigraphy for detecting a renovascular cause in hypertensive patients with renal failure and to assess the ability to predict the beneficial effect of revascularization on renal function. METHODS: Thirty-eight patients with renal failure (mean glomerular filtration rate = 35 mL/min) underwent renal scintigraphy after injection of 99mTc-mercaptoacetyltriglycine. Baseline scintigraphy was performed, and the test was repeated 24 h later after oral administration of 50 mg captopril given 60 min before the test. RESULTS: In 5 of 6 patients with a renovascular cause for renal failure, and 2 of 3 patients with a probable arterial pathology, scintigraphy had a high probability. The result was indeterminate in the other 2 patients. In 5 of 11 patients with negative arteriography and 14 of 18 patients with probable absence of renovascular pathology, we found a low probability of functional renal artery stenosis. Six revascularization procedures were performed and were predictive of a beneficial effect in 5 patients. Time of peak activity was an effective predictor in each case. CONCLUSION: In hypertensive patients with renal failure, captopril renal scintigraphy can detect hemodynamic dysfunction downstream from a renal artery stenosis and can predict the beneficial effect of revascularization in some cases.     

99Tcm-DMSA肾显像在小儿泌尿道感染中的应用

目的 探讨^99Tc^m-二巯基丁二酸（DMSA）肾显像对鉴别小儿上、下尿路感染（UTI）、判断肾瘢痕和指导临床治疗的价值。方法 对近5年来临床诊断UTI252例患儿^99Tc^m-DMSA肾显像结果进行分析。其中男94例，女158例，年龄1个月-14岁。肾显像采用常规方法，并计算分肾功能。显像结果分为正常[诊断为下尿路感染（LUTI）]和异常[诊断为上尿路感染（UUTI）或肾瘢痕]。结果 252例UTI患儿，110例显像正常，诊断为LUTI；142例显像结果异常，诊断为UUTI，其中116例为急性肾盂肾炎（APN），26例为肾瘢痕。LUTI者分肾功能为46％－54％。UUIT者单肾受累患者中，其受累肾脏分肾功能均低于45％（13％－44％）。UUTI患儿中有17例经正规抗感染治疗后再次显像，其中13例APN患儿，12例6个月后随访，显像结果均转正常或明显好转，1例4个月后随访无明显变化；4例肾瘢痕形成者6个月后复查无明显变化。结论 ^99Tc^m-DMSA肾显像鉴别小儿UTI无创伤，简便易行，可靠，尤适用于儿童。     

MR pyelography in 115 patients with a dilated renal collecting system

Purpose: To evaluate the accuracy of MR pyelography in the assessment of hydroureteronephrosis.Material and Methods: One hundred and fifteen patients, with variable degree of hydroureteronephrosis demonstrated by US and urography were subjected to MR pyelography obtained by means of two ultra-fast sequences.Results: Of the 228 kidneys examined, the collecting systems of 130 kidneys were dilated and correctly identified on MR pyelography, with only 2 false-positive results. The specificity of MR pyelography in detecting hydronephrosis was 98%. Accuracy in revealing level of obstruction was 100%. Sensitivity in detecting stones, strictures and congenital ureteropelvic junction obstructions was respectively 68.9%, 98.5% and 100%.Conclusion: MR pyelography can rapidly and accurately depict the morphological features of dilated urinary tracts with information regarding the degree and level of obstruction, without using contrast medium or ionizing radiation.     

Technetium-99m-L,L-ethylenedicysteine scintigraphy in patients with renal disorders

Technetium-99m-L,L-ethylenedicysteine (^99mTc-L,L-EC), a new renal imaging agent, was introduced as an alternative to^99mTc-mercaptoacetyltriglycine (MAG3). This radiopharmaceutical can be easily labelled at room temperature and has high radiochemical purity and long stability. The aim of this study was to gain clinical experience in using^99mTc-L,L-EC in normal volunteers and patients. The clearance of this radiopharmaceutical was compared with that of iodine-131ortho-iodohippurate (OIH) in five healthy volunteers. In addition, conventional renogram and whole-body distribution of^99mTc-L,L-EC (40 min and 3 h post-injection) were evaluated in these subjects. Subsequently, ten patients with suspected obstructive nephropathy, four with renovascular disorders and two in acute renal failure were imaged. In five patients with impaired renal function both^99mTc-MAG3 and^99mTc-L,L-EC studies were performed. In each case the scintigraphic images and time/activity curves were evaluated and various semiquantitative parameters calculated and compared. No adverse effects were noted during and after^99mTc-L,L-EC scintigraphy. The mean clearance values for^99mTc-L,L-EC and¹³¹I-OIH in volunteers were 504 and 663 ml/min respectively. The total plasma clearance of^99mTc-L,L-EC was about 75.8% of the¹³¹I-0IH value. In volunteers the parenchymal transit time index, whole kidney transit time index and mean parenchymal transit time for^99mTc-L,L-EC were 63 s, 124 s and 175 s respectively. The mean time to peak activity was 235 s and the time from peak to 50% of peak activity was 402 s. In all patients the results of scintigraphy were concordant with clinical findings and subsequently influenced patient management. Furthermore,^99mTc-L,L-EC scintigraphy provided high-quality images similar to those obtained with^99mTc-MAG3, even at low glomerular filtration rates (18 ml/min). It is concluded that^99mTc-L,L-EC has excellent imaging characteristics similar to^99mTc-MAG3 and excretion properties similar to OIH. This radiopharmaceutical can be used routinely to evaluate patients with renal disorders.     

Bone scintigraphy in evaluation of the effect of renal transplantation in the patients with renal osteodystrophy

Bone scintigraphy before and after renal transplantation was studied in 10 patients with renal osteodystrophy. The hemodialyses, which resulted in renal osteodystrophy, were maintained for years in all cases before renal transplantation. The radionuclide distribution patterns visualized on the images before transplantation were classified into two groups, that is, one group with markedly increased tracer uptake throughout the whole skeleton, especially in the skull, another group with prominent tracer uptake in the soft tissues. These abnormal increased tracer accumulation improved after renal transplantation. Bone scintigraphy before and after renal transplantation brings about a useful information concerning the follow-up of the patients with renal osteodystrophy.     

Influence of vesicoureteral reflux and urinary tract infection on renal growth in children with upper urinary tract duplication

The growth of the renal parenchyma was examined in children with duplicated outflow systems, vesicoureteral reflux (VUR), urinary tract infection (UTI) and no sign of obstruction. Ten patients with reflux occurring only in the caudal system (group A) and 4 patients with reflux both to the caudal and the apical system (group B) were studied shortly after their first UTI (study 1) and then 1.5 to 9 years later (study 2). The frequency of UTI was relatively high during the follow-up period. At urography, renal length and renal area were normal in group A in studies 1 and 2. Parenchymal thickness of the apical pole (APT/L) did not differ from normal values in any of the studies. Parenchymal thickness of the caudal pole (CPT/L) was significantly smaller than normal in both studies. There was also a significant decrease in CPT/L between study 1 and 2. UTI during the first year of life was associated with a greater reduction in CPT/L. The determination of renal length and renal area in children with a duplicated ureter, VUR and UTI, does not identify subjects at risk of developing renal growth retardation while serial determinations of parenchymal thickness appear to be an appropriate method.     

Detection of renal artery stenosis by means of captopril renal scintigraphy in patients with multiple renal arteries.

Both captopril renal scintigraphy (CRS) and conventional arteriography were retrospectively evaluated in 64 patients to study CRS efficacy in hypertensive patients with multiple renal arteries (MRA). The presence of MRA was angiographically demonstrated in 9 patients, 7 unilaterally and 2 bilaterally, with a total of 11 kidneys supplied by 2 or more arteries. Overall, 25 MRA were identified and 7 were affected by stenosis of > 50%, causing a reduction of arterial supply in 5 of 11 kidneys. CRS correctly diagnosed all five ischemic kidneys (true positives) and five of six nonischemic kidneys (true negatives); in one case in which perfusion was not reduced, the CRS diagnosis was falsely positive. In the presence of MRA, CRS proved effective in identifying renal artery stenosis of > 50%, involving either one or all the MRA. This study shows that the presence of MRA is not a drawback in the evaluation of renal artery stenosis by means of CRS.     

Renal scintigraphy in children with urinary tract infections

BACKGROUND/AIM: To determine the incidence of abnormal Technetium Tc 99m Dimercaptosuccinic Acid (Tc99m DMSA) renal scintigraphy findings in the children with urinary tract infection (UTI), and to evaluate the difference between the children with UTI and vesico-ureteral reflux (VUR), and the children with UTI without VUR. METHODS: Tc99m DMSA renal scintigraphy was performed in 170 children with UTI, mean age 7.07 years (1 month to 14 years, 137 were girls and 33 were boys). In 88 of the children, VUR was proved by micturating cystouretherography (MCU), while in 82 VUR could not be detected by MCU. VUR was graded in accordance with MCU recommended by the intemational study of VUR. In 13 of the children the grade of VUR was grade I, in 30 was grade II, in 23 grade III, in 17 grade IV, while the grade V was in 5 of the children. Findings of Tc99m DMSA renal scintigraphy were classified as: 1--normal, 2--probably normal, 3--equivocal, 4--probably abnormal, and 5--abnormal. The degree of the significance of the difference of the findings was estimated using chi2, taking p < 0.01 as the limit of statistical significance. RESULTS: Of the total number of 170 studied children, the abnormal findings were detected in 30% (51/170), normal findings in 62% (106/170), and equivocal in 8% (13/170). In the children with UTI and VUR, the incidence of abnormal findings was 49% (43/88), of normal 43% (38/88), and of equivocal findings 8% (7/88). All the children with VUR grade V had the abnormal findings (the incidence of the abnormal findings was 100%). In the children with VUR grade IV, the abnormal findings were 71%. In the children with VUR grade I, 77% of the findings were normal, in the children with VUR grade II 53% of the findings were normal and in the children with VUR grade III, 30% otfthe findings of renal scintigraphy were normal. In the children with UTI without VUR, the incidence of abnormal findings was 10% (8/82), of normal findings 83% (68/82), and of equivocal findings 7% (6/82). The incidence of abnormal findings was significantly higher in the children with UTI and VUR than in those with UTI without VUR (p < 0.01). Also, the incidence of the abnormal findings was higher in the children with VUR grades IV and V than in the children with VUR grade I (p < 0.01). CONCLUSION: DMSA renal scintigraphy in the children with ITU revealed the abnormal findings in 30% of the cases. The incidence of the abnormallfindings was signficantly higher when VUR was present, as well as if the grade of VUR was higher. Our results confirmed that Tc99m DMSA renal scintigraphy was a very important technique in the evaluation of the children with ITU.     

Comparison of four different preparation protocols to achieve bladder distension in patients with gross haematuria undergoing a CT urography

IntroductionCT examination has been shown to be effective in detecting bladder cancer. Proper evaluation of the bladder requires it to be well distended. The purpose of the present study was to establish a preparation protocol to achieve satisfactory bladder distension without causing unacceptable patient discomfort.Material and methodWe used four different preparation protocols (1: 0.5 L of fluid intake during a 1-h period, 2: Same as 1 with the addition of IV diuretics when the patient was examined, 3: 1 L of fluid intake during a 2-h period, 4: Same as 3 with the additional instruction to empty the bladder after 1 h. In protocols 1–3, the patients were asked not to empty their bladder during the preparation time). Bladder volume was calculated and bladder distension was judged as satisfactory or not by the radiologist. The patients answered questions about their ability to follow the preparation protocol and were requested to rate their need to empty the bladder pre-, during and post-examination.ResultsProtocol 1 had the lowest bladder volume. Protocols 2, 3 and 4 were similar in bladder volume. However, Protocol 2 caused unacceptable patient discomfort, and the compliance was lowest in Protocol 4.ConclusionProtocol 3, drinking 1 L of fluid during a 2-h period, gave satisfactory bladder distension, did not cause unacceptable discomfort in patients and did not have the lowest compliance.