[Effect of wall thickness of left ventricle on 201Tl myocardial SPECT images: myocardial phantom study]

201Tl myocardial SPECT is known for better sensitivity, specificity, and accuracy than planar images in detecting coronary artery disease and diagnosing myocardial viability. SPECT images are also superior to planar images in diagnostic sensitivity and anatomical orientation. However, as limitation of the spatial resolution of the machine, we often encounter poor SPECT plower image quality in patients with decreased wall thickness. To test the accuracy of SPECT images in patients with marked thinning of the left ventricular wall, as occurs in dilated cardiomyopathy, we performed a experimental study using myocardial phantom with 7 mm wall thickness. Tomographic image of the phantom images were rather heterogeneous, though no artificial defect was located. Dilated cardiomyopathy is thought to be characterized by patchy defects in the left ventricle. Careful attention should be given to elucidating myocardial perfusion in patients with a thin left ventricle wall, as there are technical limitations in addition to clinical features.