[Evaluation of left ventricular function using gated planar myocardial imaging with Tc-99m-MIBI]

Area of Science:

• Nuclear Cardiology
• Cardiovascular Imaging
• Medical Physics

Background:

• Assessing left ventricular (LV) function is crucial in diagnosing and managing heart disease.
• Traditional methods for evaluating LV wall motion can be invasive or have limitations.
• ECG-gated planar myocardial imaging offers a non-invasive approach to assess cardiac function.

Purpose of the Study:

• To develop and validate a quantitative index for left ventricular wall motion from ECG-gated planar myocardial images.
• To compare this novel index with ejection fraction (EF) derived from contrast ventriculography (LVG) and radionuclide ventriculography (RNV).
• To assess the ability of the index to reflect regional wall motion abnormalities.

Main Methods:

• Developed a quantitative index, %count increase (CI), based on end-diastolic and end-systolic myocardial activity from Tc-99m-MIBI gated planar scintigraphy.
• Measured mean myocardial activities using circumferential profile analysis.
• Compared global %CI with EF from LVG (n=29) and RNV (n=24).
• Assessed regional %CI against LVG-evaluated wall motion in 39 heart disease patients and 5 normal controls.

Main Results:

• The global %CI showed strong correlations with EF from LVG (r=0.70) and RNV (r=0.75).
• Regional %CI significantly decreased in areas with worsened wall motion as assessed by LVG.
• The developed index provides quantitative data on both global and regional left ventricular function.

Conclusions:

• ECG-gated planar myocardial perfusion imaging with Tc-99m-MIBI is a valuable tool for assessing left ventricular function.
• The quantitative index derived from this imaging modality provides reliable information on global and regional ventricular wall motion.
• This technique offers complementary functional information alongside myocardial perfusion assessment.