Uniformity comparison: Automatic vs. manual SPECT/CT quality control

Objectives Quality control (QC) is an integral part of any Nuclear Medicine department. The main goal of QC is to ensure optimal system performance so that reliable, high quality images can be produced to aid in diagnosis. The purpose of this study was to compare uniformity analysis results between automatic and manual quality control on the Symbia TruePoint SPECT/CT (Siemens Medical Solutions USA).

Methods Integral and differential uniformity analysis was evaluated for manual and automatic intrinsic and extrinsic QC. Manual intrinsic verification was completed by removing the collimators and inserting a 26-31mCi ^99mTc point source in the integrated point source holder. Automatic intrinsic verification was performed by using the AutoQC device with an internal ^99mTc point source. Manual extrinsic verification was accomplished by placing a ⁵⁷Co sheet source on the collimated detector and running the manual extrinsic QC protocol. Automatic extrinsic sweep was performed using the internal ¹⁵³Gd source. Five same day runs of automatic and manual extrinsic and automatic and manual intrinsic QC were performed and the data collected.

Results Both the intrinsic and extrinsic automatic vs. manual verification data favored manual uniformity analysis, with the exception of extrinsic Differential UFOV. The average variances are listed in the tables below.

Conclusions Overall, uniformity analysis favored manual QC over automatic. Visual comparison of manual and automatic uniformity images is consistent with the above results. Additional data will continue to be collected to further validate these findings.