17-segment scoring (perfusion and function)
All categorical polar maps and polar map and functional surface overlays in QGS and QPS currently available in the 20 segment format will also be made available in the AHA standard 17 segment format. Selection of the active configuration (17 or 20 segments) will be possible through a menu presented in the Defaults Dialog, so that any such change in configuration can be made both within and across application invocations. Presentation of 17 segment polar maps and polar map and functional surface overlays will be identical to those for 20 segments, with the exceptions that the 2 apex segments will be replaced with a single segment, and that the 6 most apical short axis segments will be replaced with 4 segments, as per the AHA standard.
17 segment categorical scores will be able to be automatically generated using either 17 or 20 segment normal limits, and in QPS the user will be able to create and manage 17 segment databases and normal limits using the same mechanisms currently available for 20 segments. 20 segment categorical scores, however, will not be able to be automatically generated using 17 segment normal limits.
Summed perfusion scores will be presented both in numerical form (SSS, SRS, etc) and as a percentage of the maximal numerical values obtainable (SS%, SR%, etc). The latter are independent of the number of segments used.
Eccentricity index measurement
Any static short axis datasets with associated LV contours will have the eccentricity of its mid-myocardial wall for each interval automatically computed, and expressed as an eccentricity index. The eccentricity index of the currently displayed interval will then be displayed in the QPS Information Box as ECC, and will have values between 0 and 1 (0=sphere, 1=line). The eccentricity/sphericity of the LV is a measurement tightly related to the amount of remodeling associated with the LV.