Three-dimensional ROI-based quantification of stress/rest 201Tl myocardial SPECT: presentation of a method.

A semiautomated method for three-dimensional quantification of stress/rest 201Tl myocardial SPECT of the left ventricle (LV) is introduced. A total of 33 ringsegment-shaped regions of interest (ROIs) are distributed over 6 oblique (short axis cuts) double-slices (thickness 1.3 cm) from LV apex to base, commencing with 1 ROI for the apex up to 8 ROIs for the base (1-4-4-8-8-8). Within the last two double slices an additional adjacent ROI is automatically placed in the upper right quadrant to observe lung TI-uptake. Correspondence of slices for exercise and rest is achieved by adjusting the long axis outlines rebuilt from summed profiles of 15 oblique slices of each examination. Calculated numeric arrays of the extracted parameters (vitality, washout and redistribution) are displayed in a target-like two-dimensional polar fashion.