Nuclear Cardiology: Nuclear Cardiology:

Chapter 14 / Artifacts and Technical Problems in Cardiac Imaging 187Fig. 14-56. Quantification of the SPECT slices in Figs. 14-54 and 14-55 usingcircumferential count distribution profile analysis. The yellow curves representthe count distribution on the stress images and the red curves represent the restimages. The white curve represents the lower limit of normal radiotracer distribution(mean minus two standard deviations). The stress and rest curves arewithin the lower limit of normal in the apical, midventricular, and basal shortaxisslices. The apical segment is quantified from a mid horizontal long-axisslice and is normal as well. In the table at the top the results of computer quantificationare shown. No defects are quantified. These are quantitatively normalSPECT images.INCORRECT ORIENTATION OF TOMOGRAPHIC AXIS(FIG. 14-57 TO FIG. 14-60)The first step in reconstruction of tomographic images is to createtomographic slices that are oriented along the anatomical axis of thebody, resulting in transverse, coronal and sagittal slices. Since the heartis positioned in the chest at an angle to the body axis, interpretation of