Evaluation of Renal Parenchymal Defects with 99mTechnetium Mercaptoacetyltriglycine Scintigraphy Using a Modified Grading and Scoring System: Comparison with 99mTechnetium Dimercaptosuccinic Acid

Objective: The aim of this study was to evaluate whether cortical scars can be detected using the summed images of 99mTechnetium- mercaptoacetyltriglycine (99mTc-MAG3) renal dynamic scans, and to compare the results with 99mTechnetium-dimercaptosuccinic acid (99mTc-DMSA) scans. Materials and Methods: We evaluated a total of 135 renal units from 68 patients (12 boys and 56 girls, with a mean age of 9 years old; range 3-16 years old) who had 99mTc-MAG-3 and 99mTc-DMSA scintigraphy within a period of two weeks. Differential renal function (DRF) values and parenchymal function parameters obtained from the two studies were compared with semiquantitative scoring and grading systems. Results: The correlation between 99mTc-MAG-3 and 99mTc- DMSA cortical scintigraphy, according to the semiquantitative scoring and grading systems, was perfect (rk tau-b=0.833). The sensitivity, specificity, and accuracy of 99mTc-MAG-3 scintigraphy were 92.6%, 96.8%, and 95.5%, respectively. There was no significant difference between two methods in detecting renal scars (p 0.05). Conclusion: Most parenchymal lesions detected on 99mTc- DMSA scans were also identified on 99mTc-MAG-3 parenchymal scans. By lowering the radiation exposure, 99m-Tc MAG-3 scintigraphy can provide simultaneous information on renal perfusion, concentration, drainage, parencymal functions, and DRF without the need for additional imaging methods. The reliability of renal parenchyma evaluation was increased by using scoring and grading systems to compare the two methods.