Sequential sampling: A new acquisition technique for fatty acid kinetics from quasi-simultaneous multiple projections

Studies of myocardial metabolism by rapidly catabolized fatty acids like -I-123-heptadecanoic acid (IHA) are usually limited to one planar view of require sophisticated equipment, such as bidirectional slant-hole collimators or seven-pinhole collimators for multiplane or tomographic views. To solve this problem a normal SPECT camera was utilized to acquire sequentially sampled dynamic studies from up to six different views. This was done by a periodically repeated sequence of acquisitions in different projections, which followed one another clockwise. This procedure overcomes the single-plane limitations of the usual IHA dynamic studies. It reveals regional myocardial patterns of tracer uptake and elimination not obtainable from any single viewing angle. In this way one methodological disadvantage relative to thallium perfusion studies is removed. Furthermore, the non-invasive diagnosis of cardiomyopathies, for which no other radioisotope procedure is appropriate, should be improved using this new method.