Purpose The aim of this study was to investigate the value of dual-phase 99mTc-MIBI SPECT/CT in the differential diagnosis between benign and malignant enhancing solid renal tumors. Patients and Methods Totally, 180 patients were imaged with dual-phase 99mTc-MIBI SPECT/CT, which was performed 30 minutes and 90 minutes after 99mTc-MIBI administration. Among them, 147 patients with 148 histologically proved solid renal tumors met the selection criteria and were included for the final analysis. Relative quantification was performed by measuring the radioactive uptake ratio of tumor to the normal renal parenchymal background for both early and delayed images. Results Benign renal tumors (4 renal oncocytomas and 8 lipid-poor angiomyolipomas) demonstrated a significantly higher early relative uptake value (ERUV) and delayed relative uptake value (DRUV) than malignant renal tumors (n = 136; both P < 0.0001). The ERUV cutoff value of 0.53 helped to differentiate benign from malignant renal tumors, with sensitivity of 100%, specificity of 94.8%, and accuracy of 95.3% for the diagnosis of benign renal tumors. The DRUV cutoff value of 0.50 helped to differentiate benign from malignant renal tumors, with sensitivity of 100%, specificity of 96.3%, and accuracy of 96.6% for the diagnosis of benign renal tumors. There was no statistically significant difference between the efficacy of ERUV and DRUV in the differential diagnosis between benign and malignant renal tumors (P = 0.5). The efficacies of ERUV and DRUV were all significantly higher than the retention index (both P < 0.0001). Conclusions Both early and delayed phase 99mTc-MIBI SPECT/CT are helpful for distinguishing benign renal oncocytoma and lipid-poor angiomyolipoma from malignant renal tumors, and the delayed phase imaging tends to show higher diagnostic accuracy.

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Cardiac MRI can determine viable myocardium and clearly delineate the location and degree of myocardial necrosis. PET slightly overestimates the extent of the necrotic myocardium and is unable to distinguish transmural necrosis from subendocardial necrosis.