[Usefulness of electrocardiogram gated 99mTc-methoxy isobutyl isonitrile (MIBI) single photon emission computed tomography for detection of wall motion abnormality of left ventricle].

We evaluated whether the newly developed perfusion imaging agent "99mTc-methoxy isobutyl isonitrile (MIBI)" has a possibility to detect wall motion abnormality of left ventricle. Electrocardiogram (ECG) gated single photon emission computed tomography (SPECT) was performed in 6 patients with myocardial infarction (anterior: 3 and inferior: 3). Apical and basal short axis images were selected from each patient and circumferential analysis was performed on end-diastolic (ED) and end-systolic (ES) images respectively. Count in end-diastole (EDC) and count in end-systole (ESC) were obtained, then % (ESC-EDC) and (ESC-EDC)/EDC were calculated. Wall motion of left ventricle was evaluated by either ultrasonic cardiogram or left ventriculography. Left ventricle was divided into anterior, septal, posterior and lateral areas and then each area was divided into apical and basal segments (finally the heart was divided into 8 segments). Of 48 segments, 33 segments showed normal wall motion and 15 segments showed abnormal wall motion: hypokinesis, akinesis and dyskinesis. % (ESC-EDC) was 74.39 +/- 16.85% in segment of normal wall motion and 33.27 +/- 23.56% in segment of abnormal wall motion (p < 0.001). (ESC-EDC)/EDC was 48.67 +/- 13.35% in segment of normal wall motion and 23.33 +/- 18.83% in segment of abnormal wall motion (p < 0.001). From these data, lower limit of % (ESC-EDC) and (ESC-EDC)/EDC in normal wall motion was defined as 40 and 22 respectively: mean -2SD of normal wall motion. Sensitivity of diagnosis of abnormal wall motion was 73% in % (ESC-EDC) and 60% in (ESC-EDC)/EDC (n.s.). Specificity was 94% and 97% (n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)