Can the Diagnostic Accuracy of Bone Scintigraphy be Maintained with Half the Scanning Time?

Abstract

Purpose: We aim to show that the acquisition time of a conventional bone scan can be reduced by one-half without loss of the diagnostic value of the scan. Materials and Methods: Fifty adult patients (37 male and 13 female, mean age 62.5, SD 8.7 years) were enrolled. Patients were injected with 25–30 mCi (925-1110 MBq) ^99mTc MDP IV. The Standard Protocol whole body planar images were acquired first [scan speed = 10 cm/min, acquisition time around 20 minutes] and were followed immediately by the Half-Time Protocol whole body planar images [scan speed = 20 cm/min; acquisition time around 10 minutes]. Both images were interpreted by two nuclear medicine physicians. Each reviewer, when reviewing the Standard Protocol images, was “self-blinded” to the result they had obtained when reviewing the Half-Time images, and vice-versa. This self-blinding was accomplished by allowing a minimum of two weeks to elapse between the two interpretations. We used the κ-coefficient to compare the agreement between the Standard-Protocol results and the Half-Time results. Results: There was no difference in clinically significant diagnostic information for Half -Time and Standard Protocol. The diagnostic quality of Half-Time and the Standard Protocol images were not significantly different (0.86 < κ < 1.0). Conclusion: Our data suggest that if we reduce the ^99mTc MDP dose by half and keep the acquisition time at its standard value we gain the benefits of reduced dose without loss of diagnostic value of the scan.