Kidney scintigraphy with 99mTc-DMSA and 131I-hippurate

Radioprotective effects of montelukast, a selective leukotriene CysLT1 receptor antagonist, against nephrotoxicity induced by gamma radiation in mice

PURPOSE

In this study, we evaluated the renal protective effects of montelukast (MLK) against ionizing radiation (IR) induced nephrotoxicity in mice.

MATERIALS AND METHODS

Radioprotective effects of MLK were assessed by biochemical analysis including measurements of kidney malondialdehyde (MDA), reduced glutathione (GSH), and serum creatinine and urea levels. Besides, for further evaluation of protective effects of MLK on renal system, ^99m Tc-dimercaptosuccinic acid (DMSA) has been applied. The total antioxidant capacity of MLK was measured by using 1,1-diphenyl-2-picryl hydrazyl radical reagents and compared with butylated hydroxyl toluene standard antioxidant.

RESULTS

The biochemical evaluation revealed that better results have been achieved for the groups administered with MLK than the only radiation group. Besides only IR-treated mice group, those treated with MLK demonstrated a significant decrease in urea and creatinine levels. Statistically, significant differences of MDA and SHG levels (P < .05) were found between the radiation group and MLK plus IR-treated group. Also, ^99m Tc-DMSA kidney uptake value (%ID/g) was observed lower for MLK plus IR-treated mice group than only radiation-treated mice group.

CONCLUSIONS

According to our findings, MLK has a potential role to be used as a renal protective agent against gamma radiation in radiotherapy.

Effect of unilateral vesicoureteric reflux on renal growth and the uptake of 99mTc DMSA by the kidney. An experimental study in the minipig

The influence of unilateral vesicoureteric reflux (VUR) on renal growth and the uptake of 99mTc DMSA by the kidney has been investigated in a 2-kidney model in the growing minipig over a period of approximately 5 months. Animals with reflux in association with low voiding pressures and normal bladder function (n = 5), as well as those with raised voiding pressures and abnormal bladder function (n = 7), were investigated with appropriate non-refluxing controls (n = 12). Urinary infection and renal scarring were avoided since these factors may affect kidney function and growth independently. Statistical tests of difference failed to demonstrate any effect of VUR on renal growth or renal uptake of 99mTc DMSA even in the presence of elevated voiding pressures and abnormal detrusor function.

Technetium-99m dimercaptosuccinic acid uptake in long-term catheterized kidney. Comparison with renal function

We studied 23 long-term catheterized kidneys in 14 patients. The uptake of 99mtechnetium dimercaptosuccinic acid (99mTc-DMSA) was measured at one- and two-hour intervals after injection, and the uptake was corrected for variations in renal depth. These values were compared with inulin, creatinine, and para-amino hippurate (PAH) clearances which were measured in each kidney by collecting urine through long-term catheterization. Correlation coefficient was obtained between PAH clearance corrected for the body surface area and the two-hour uptake of 99mTc-DMSA. The correlation coefficients between the two-hour uptake of 99mTc-DMSA and the clearance values are not significantly different from those between the one-hour uptake and the clearance values. Corrections of the uptake for variations in renal depth did not improve the correlation coefficients. The results show that 99mTc-DMSA is an excellent method to estimate the renal plasma flow and the one-hour uptake without correction for renal depth is clinically sufficient to evaluate the split renal function.

The effect of radiopharmaceutical choice on the assessment of the relative renal function in upper urinary tract obstruction

The relative function of the obstructed kidney (RFOK) was assessed in 43 adult patients with upper urinary tract obstruction (UUTO) using 99mTc-DTPA and 131I-ortho-iodohippurate (OIH) dynamic studies and 99mTc-DMSA dynamic and static studies. The patients were divided into five groups according to the duration and degree of obstruction. Findings were as follows: a) in patients with the first occurrence of acute severe obstruction (group 1), the relative glomerular filtration rate (GFR) was significantly less than the relative effective renal plasma flow (ERPF); b) in patients with chronic severe obstruction and long term uroinfection, the relative ERPF decreased significantly compared with the relative GFR; c) the RFOK calculated from the DMSA dynamic study was the same as both the relative GFR or ERPF in any group; d) the RFOK calculated from the DMSA static study seemed to parallel the relative ERPF more closely than the relative GFR, but in group one it was significantly higher than any of three other estimates. It is concluded that 99mTc-DTPA is the radiopharmaceutical of choice in obstructive uronephropathy, but when interpreting the RFOK, the time course and severity of obstruction, the presence or absence of uroinfection should also be considered.

Evaluation of renal parenchyma in children by DMSA scintigraphy, X-ray computed tomography and intravenous urography

The demonstration of diminished or scarred renal parenchyma in children is often the decisive factor in determining the future management of children with urinary tract malformations. Renal scintigraphy using technetium 99m-labelled dimercaptosuccinic acid (DMSA), computed tomography (CT) and intravenous urography (IU) were used to evaluate the renal parenchyma prior to ureter re-implantation in a series of 13 children. Their ages ranged from 5 months to 3 years 8 months. The indication for operation was ureteric reflux in 8 children and distal ureteric stenosis in 5. CT was performed on a Toshiba TCT-80 scanner. Renal scintigraphy was performed 3 hours after intravenous injection of DMSA. Compared with IU, DMSA imaging gave more information about the renal parenchyma in 6 children, gave equal information in 6 and less in 1. Compared with CT, DMSA imaging gave more information in 2 children, was equally informative in 8 and less so in 3. Accordingly, DMSA imaging was judged to be more sensitive than IU and as sensitive as CT. DMSA imaging can be used both for the initial evaluation and for follow-up assessment of renal parenchymal damage.

Radioisotopic evaluation of the renal parenchymal function in children with ureteropelvic junction obstruction. A retrospective study

Separate glomerular filtration rates were evaluated in 21 children with uni- or bilateral ureteropelvic junction stenosis, using the Tc-99m DTPA complex and the scintillation camera. The grade of alteration seen on urograms has influenced the surgeon in his decision to use a conservative or a surgical treatment, whereas the type of intervention (pyeloplasty or nephrectomy) was mainly based on the scintigraphic quantitation. The morphological data provided by an excretory urogram could not predict the degree of functional impairment. The scintigraphic evaluation of single kidney clearance was useful in the evaluation of the effects of medical and surgical treatment.

99mTc-DTPA and 99mTc-DMSA renal gamma imaging in the surveillance of patients with conduit urinary diversion

We studied renal anatomy and function using 99mTc-2-3 dimercaptosuccinic acid (DMSA) and 99mTc-diethylenetriaminepentaacetic acid (DTPA) in 27 patients with conduit urinary diversion. In this condition, free ureteral reflux is often associated with bacteriuria, and these factors are thought to precipitate progressive renal deterioration. Gamma-camera images provided valuable information concerning the structure of the renal parenchyma, the function of individual kidneys and possible ureteral obstruction, thus helping us to decide whether or not to instigate further treatment. The information gained using renal gamma imaging with 99mTc-DTPA and 99mTc-DMSA was complementary and partly overlapping. We preferred the use of 99mTc-DTPA because of its ability to visualise the ureters and the region of ureteroconduit anastomosis. Using diuretic medication, we were able to differentiate true ureteral obstruction from atony in 9 patients using 99mTc-DTPA.

Combined [99mTc]DMSA kidney scintigraphy and [131I]hippuran renography in children with urinary tract infections

Combined [99mTc]DMSA kidney scintigraphy and [131I]hippuran renography were performed consecutively in 87 children with recurrent urinary tract infections in a retrospective study. This procedure allows a description of renal cortical morphology, split function determination and run-off evaluation. Signs of cortical scarring were found in 41 of 172 kidneys (24%) and were significantly associated with vesico-ureteral reflux (p less than 0.001) and with delayed urinary run-off (p less than 0.01). Split renal function was significantly reduced in kidneys with unilateral scarring (p less than 0.001). The radio-isotope investigations and intravenous urography were performed within 3 months of each other in 56 patients (110 kidneys). Good agreement between the findings was found except for 13 kidneys, where cortical activity defects were revealed by scintiscan despite normal urography. The extended scintigraphic procedure described is considered useful for urological screening of children with urinary tract infections and may thus replace urography as a first-line investigation. It should be followed by micturition cysto-urethrography when evaluation for vesico-ureteral reflux is indicated.

Radionuclide scanning--new applications in urology

The current status of nuclear renal scanning and function evaluation is summarized. The indications for renal imaging are discussed. Techniques for measurement of split and total renal function are reviewed. Special attention is given to the role of renography (conventional and diuretic) in the evaluation of the obstructed kidney.

A clinical study of 99mTechnetium dimercaptosuccinic acid uptake in obstructed kidneys: comparison with the creatinine clearance

We studied 17 hydronephrotic kidneys owing to stenosis of the pyeloureteral junction. Preoperative uptake of 99mtechnetium dimercaptosuccinic acid was compared to early postoperative unilateral creatinine clearance, measured by urine collection from the nephrostomy tube. An excellent correlation was found. Therefore, uptake of 99mtechnetium dimercaptosuccinic acid represents a reliable parameter of renal function even in the presence of severe urinary tract obstruction. However, 99mtechnetium dimercaptosuccinic acid uptake should be measured more than 24 hours after injection of the tracer.

Renal radiopharmaceuticals--an update

Noninvasive radionuclide procedures in the evaluation of renal disease have been accepted increasingly as effective and valuable alternatives to older clinical methods. The development of suitable radiopharmaceuticals labeled with high photon intensity radionuclides and with 99mTc in particular has stimulated this modality during the last few years. Currently several nearly ideal agents are available for anatomical and functional studies of kidney imparting very low absorbed radiation doses. These include 99mTc-GHA and 99mTc-DMSA for renal morphology and differential function evaluation, 99mTc-DTPA for GFR and 123I orthoiodohippurate for ERPF measurements. A suitable agent as a replacement for the latter labeled with 99mTc is actively being sought. Computer-assisted processing of dynamic renal function studies enables the observer to obtain a wealth of information related to the renal extraction, uptake, parenchymal transit and pelvic transit parameters of the agent administered into the bloodstream. Each of these parameters either globally or differentially contributes to a detailed evaluation of renal disease states. Several of these procedures have been validated against classical techniques clinically but more detailed information is being sought with the recently introduced radiopharmaceuticals. With the detailed validation and increasing recognition of the clinical utility of several of the radionuclidic procedures at many centers, it is hoped that radionuclide assessment of renal disorders ultimately will be made available routinely at all medical facilities.

Role of modern radiological investigations in obstructive uropathy

Obstructive uropathy in its various forms accounts for much of the work load in urological units and general hospitals. Until recently, laboratory tests and excretion urography were the only procedures available for its assessment. The past few years have seen the development and refinement of ultrasound, examination by computer tomography, nuclear medicine, antegrade pyelography, and perfusion pressure flow studies. This paper examines the particular qualities of these modern procedures and their role in the clinical assessment of the obstructed urinary tract.

The dilated non-obstructed renal pelvis

This paper discusses 28 patients with renal pelvic dilatation in whom obstruction was excluded by excretion urography and diuresis renography. The clinical presentation and progress of the patients over a follow-up period of 1 to 5 years are presented. One patient required pyeloplasty, one developed 2 asymptomatic pelvic calculi and one showed some deterioration in function on the affected side. The remaining 25 patients remain well and their follow-up renograms show satisfactory renal function and excretion. Before the advent of objective means of assessing renal function and urodynamics, these patients would probably have been subjected to pyeloplasty. The present study confirms that the correct management of the dilated non-obstructed renal pelvis is conservative.