Adopting new gamma cameras and reconstruction algorithms: Do we need to re-establish normal reference values?

Area of Science:

• Nuclear Cardiology
• Medical Imaging Technology
• Cardiovascular Physiology

Background:

• The impact of novel single photon emission computed tomography (SPECT) hardware and software on left ventricular (LV) volumes is not well-defined.
• Establishing accurate normal LV reference ranges is essential for diagnosing and managing cardiac conditions.

Purpose of the Study:

• To investigate how advancements in SPECT camera technology and reconstruction algorithms affect normal LV volume measurements.
• To determine if new SPECT systems necessitate updated reference ranges for LV volumes.

Main Methods:

• Analysis of 1953 normal patients undergoing Tc-99m tetrofosmin gated SPECT MPI.
• Exclusion of patients with prior myocardial infarction, revascularization, or known LV dysfunction.
• Comparison of LV end-diastolic volume index (EDVi) and end-systolic volume index (ESVi) across different gamma camera types (CZT vs. NaI).

Main Results:

• Significant differences in LV EDVi and ESVi were observed between CZT and dual-headed NaI gamma cameras in both men and women (P < 0.001).
• Inter- and intra-observer reliability for all LV volume measurements was excellent.
• No significant differences in LV volumes were found when comparing new resolution recovery and standard reconstruction software.

Conclusions:

• Normal LV volume reference ranges differ significantly between SPECT camera technologies.
• Camera-specific reference values are necessary for accurate interpretation of SPECT-derived LV volumes.
• Reconstruction algorithm changes did not impact LV volume measurements in this study.