Half-Time SPECT Acquisition with Resolution Recovery for Tc-MIBI SPECT Imaging in the Assessment of Hyperparathyroidism

Reduced SPECT acquisition time protocols have been recently developed based on collimator-detector response compensation reconstruction. The present study aims to evaluate the potential use of a short-time technetium-99m methoxyisobutylisonitrile (Tc99m-MIBI) SPECT algorithm in the investigation of parathyroid adenoma (PTA). Ninety patients (59 women; age range, 21-76 years) with biochemical evidence of hyperparathyroidism were referred for Tc99m-MIBI scintigraphy for diagnosis and localization of PTA. Standard full-time and half-time SPECT studies starting at 45 min after injection were performed in random order in all patients. PTA detection rate and overall image quality parameters were evaluated and graded for each study and compared for the two SPECT protocols. Focal Tc-99m-sestamibi uptake consistent with PTA was reported in 60 out of 90 studies (67%). Congruent results between the full- and half-time SPECT acquisition were found in 73 patients (81%). Minor disagreement between the two SPECT protocols with respect to PTA detectability was found in 17 patients but with no statistically significant difference (p = 0.67). The correlation coefficient between the two SPECTs was r = 0.88 (p < 0.0001), and the Bland-Altman correlation analysis confirmed the interchangeability of the two protocols. Image quality was reported as either good or excellent for all studies, and no statistical significant difference in image quality scoring between protocols was found (p = 0.155). Parathyroid MIBI SPECT can be performed using the collimator-detector response compensation reconstruction algorithm for only half of the scanning time without compromising significant diagnostic data.