SPECT blood pool phase analysis can accurately and reproducibly quantify mechanical dyssynchrony

Area of Science:

• Nuclear Cardiology
• Cardiovascular Imaging
• Medical Physics

Background:

• Single-photon emission computed tomography (SPECT) blood pool imaging offers potential for assessing mechanical dyssynchrony (MD).
• Left ventricular (LV) wall motion analysis in SPECT can utilize time-activity or time-distance curves.
• Comparing these techniques is crucial for optimizing MD detection.

Purpose of the Study:

• To compare time-activity and time-distance based SPECT phase analysis for detecting mechanical dyssynchrony (MD).
• To evaluate the diagnostic performance using receiver-operator characteristics (ROC) analysis.
• To assess the intra- and inter-observer reproducibility of both methods.

Main Methods:

• SPECT phase analysis was conducted on 48 normal subjects and 55 MD patients.
• ROC analysis was applied to phase standard deviation, synchrony, and entropy for each LV wall motion technique.
• Student t-test and regression analysis were used for statistical comparisons and reproducibility assessment.

Main Results:

• Time-activity-based phase analysis yielded excellent ROC areas (≥0.93) for all parameters.
• Time-distance techniques showed significantly lower ROC areas (0.53–0.76).
• Time-activity analysis demonstrated superior intra- and inter-observer reproducibility (correlation coefficients >0.96) compared to time-distance methods (~0.85).

Conclusions:

• SPECT time-activity-based phase analysis is highly sensitive and specific for detecting MD.
• This method exhibits excellent intra- and inter-observer reproducibility.
• Time-activity analysis is a superior technique for assessing LV mechanical dyssynchrony via SPECT.