Evaluation of renal parenchymal defects with 99mtechnetium mercaptoacetyltriglycine scintigraphy using a modified grading and scoring system: Comparison with 99mtechnetium dimercaptosuccinic acid Teknesyum-99m merkaptoasetiltriglisin sintigrafsi ile renal parankimal defektlerin modifye gradeleme ve skorlama sistemi kullani{dotless}larak deǧerlendirilmesi: Teknesyum-99m dimerkaptosüksinik asit ile karşi{dotless}laşti{dotless}rma