Added-value of 99mTc- DMSA SPECT/CT to planar imaging in detecting renal cortical defects.

Introduction: Background /Aim: ^99mTc-dimercaptosuccinic acid (DMSA) planar scintigraphy is an optimal method for assessing renal scaring, especially in children, yet the value of single-photon emission computed tomography/ computed tomography (SPECT/CT) is not well established. The aim of this study was to compare planar and SPECT/CT imaging in patients with suspected renal cortical scarring.

Methods: Patients and Methods: Patients with clinically suspected renal cortical defects were enrolled in this prospective study. ^99mTc-DMSA planar images were acquired approximately 3 h. after I.V injection of about 185 MBq of the tracer. SPECT/CT images were acquired immediately after the planar ones. An experienced nuclear medicine physician interpreted the images independently and was blinded to both clinical data and the results of other imaging methods. Both images were scored as 0; no defects, 1; single defect, 2; multiple defects, 3; equivocal, and eventually, we compared the results of both modalities.

Results: Results: Seventy-two patients; (46 males and 26 females, mean age; 34.17_/+18.1 years) were recruited in this study. On lesion based analysis, planar images detected 20 single and 21 multiple defects while SPECT/CT images detected 29 single and 44 multiple defects. Both imaging techniques agreed in the reading of 66 kidneys with score 0, and 41 ones with scores 1& 2 (P< .01). Score 3 was found on planar images in 33 kidneys; 4 out of them were confirmed normal in the SPECT/CT images, while the remaining 29 lesions were proved to have a single defect at the SPECT/CT images. Four normal kidneys in planar images were confirmed to have a single small defect in the SPECT/CT images.

Conclusions: Conclusion: ^99mTc- DMSA SPECT/CT imaging detects more renal cortical defects than the planar one in patients with suspected renal cortical scarring. Additionally, it clarifies the equivocal lesions seen in the planar images.