Hybrid cardiac SPECT/64-slice CTA-derived LV function parameters: correlation and reproducibility assessment

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Radiology

Background:

• Accurate assessment of left ventricular (LV) function and volumes is crucial in managing coronary artery disease.
• Hybrid SPECT/CT imaging offers a single-session approach for comprehensive cardiac evaluation.
• Evaluating the correlation and reproducibility of parameters derived from different imaging modalities is essential for clinical application.

Purpose of the Study:

• To determine the relationship between SPECT and CT angiography (CTA) measured LV parameters (function and volumes).
• To assess the reproducibility of LV parameters measured using 64-slice CTA.
• To evaluate LV parameters in a single session using a SPECT/CT hybrid device.

Main Methods:

• Seventy-six patients with suspected or known coronary artery disease underwent simultaneous SPECT and 64-slice CTA.
• LV end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were measured using both modalities.
• Intra-observer and inter-observer variability for CTA measurements were calculated.

Main Results:

• A strong correlation was observed between SPECT and CTA for LVEF (r=0.81), ESV (r=0.90), and EDV (r=0.82).
• CTA measurements showed small positive differences for LVEF and more prominent differences for ESV and EDV compared to SPECT.
• Excellent reproducibility was found for all CTA-measured LV parameters, with very low intra- and inter-observer variability.

Conclusions:

• While LVEF measurements from CTA and SPECT correlate well, their interchangeable use requires caution.
• Interchangeable use of LV EDV and ESV measurements between CTA and SPECT should be avoided due to significant differences.
• CTA demonstrates high reproducibility for LV volume and function assessment.