[Qualitative determination of infarct segment by Fourier analysis using gated cardiac pool emission computed tomography].

As a new method for regional wall motion analysis, the tomographic functional images, including "coronal", "sagittal" and "four-chamber" sections, were produced by applying the fundamental Fourier analysis using gated cardiac pool emission computed tomography (POOL-SPECT). Segmental wall motion was qualitatively assessed from the functional images in 10 normal subjects and in 48 patients with myocardial infarction. The results were compared with those assessed by gated blood pool planar images (modified LAO 45), two-dimensional echocardiography (2DE) or contrast left ventriculography (LVG). The following results were obtained. 1. POOL-SPECT imaging could separate the ventricle in three dimensions from the neighboring cardiovascular system by avoiding the overlapping blood pool to make accurate recognition of regional wall motion. 2. The functional tomograms had greater clinical efficacy in the diagnosis of infarcted segments than did the conventional equilibrium method, with high sensitivity (93/99, 93.9%), specificity (128/141, 90.8%) and accuracy (221/240, 92.1%), especially in the apical and inferoposterior portions. 3. Tomographic functional imaging facilitated estimating segmental cardiac performance from spatial and temporal aspects. The amplitude image which expresses regional stroke volume was readily available to detect hypokinesis and akinesis. The phase image of the initial cardiac movement was very useful for diagnosing dyskinesis. 4. In comparing the qualitative analysis with 2DE or LVG, complete agreement was observed in 80% (128/160) and 85.1% (149/175) of segments, though POOL-SPECT imaging showed underestimations in 11% of the segments. In conclusion, POOL-SPECT can be performed repeatedly without potential risks and the tomographic functional images derived from application of Fourier analysis to POOL-SPECT images are very useful for qualitative and three-dimensional analysis of regional wall motion. Thus, this technique may be a promising procedure in clinical investigations, obviating the disadvantages of conventional methods.