An effective time reduction strategy in whole-body SPECT/CT studies using novel acquire during step mode without compromising diagnostic image quality

Purpose

WB-SPECT/CT can provide valuable insight into metastatic disease, assist in diagnosing numerous conditions, and enable volumetric dosimetry. Various approaches have made whole-body (WB) SPECT/CT less feasible in routine practice as it takes impractically long acquisition times. We aim to determine whether acquire during step (ADS) technology can be used for WB SPECT/CT studies to minimise acquisition time without compromising diagnostic quality.

Design

Two different phantom studies were performed using ^99mTc and ¹⁷⁷Lu. An initial comparison of step-and-shoot (SSM) and ADS SPECT acquisition mode with full-time, half-time, and quarter-time was carried out. The recovery coefficients were calculated for different spheres and background regions to check the quantitative accuracy of SSM and ADS modes with different acquisition times. The xSPECT quantification tool was used to obtain the SUVs in the VOI.

Result

The SPECT scan time with full-time ADS was 3.5 min quicker for each bed compared to full-time SSD. The ADS mode saved 15%-of acquisition time compared to the SSM mode. For both ^99mTc and ¹⁷⁷Lu, no statistical difference in recovery coefficients was noted between different acquisition times in SSM and ADS mode. No significant changes were noted in the background SUV between SSM and ADS for ^99mTc and ¹⁷⁷Lu isotopes.

Conclusion

A 15%-time reduction could be achieved using ADS technology in our SPECT/CT scans without any change in quantitative accuracy. We also found that time can be reduced further, and scans can be acquired faster by implementing a half-time or quarter-time ADS in routine practice without compromising quantitative accuracy. The improvements in WB SPECT acquisition time could reduce motion artefact, especially for patients with pain and improve the accuracy of disease diagnosis and personalised dosimetry.