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

A quantitative index of left ventricular wall motion obtained from ECG-gated planar myocardial images has been developed. Five normal controls and 39 patients with heart disease received an injection of Tc-99m-MIBI (550-740 MBq) at rest, and ECG-gated planar scintigraphy (LAO view) was performed 3 h later. Mean End-diastolic (ED) and end-systolic (ES) myocardial activities were measured using circumferential profile analysis and %count increase (CI) was determined according to the following formula; (ES count-ED count)/(ED count) x 100. The global %CI was compared with the EF obtained from contrast ventriculography (LVG; n = 29) and radionuclide ventriculography using Tc-99m-labelled RBC (RNV; n = 24). The regional %CI was compared with left ventricular wall motion assessed by LVG. The global %CI was correlated well with EF by LVG (r = 0.70) and EF by RNV (r = 0.75). The regional %CI significantly decreased in accordance with wall motion on LVG worsened at impaired region. In conclusion, gated perfusion imaging with Tc-99m-MIBI provides useful information on ventricular function in addition to myocardial perfusion.