Integration of high velocity test object motion into a channelized Hotelling observer for the assessment of x-ray angiography systems.

Integration of high velocity test object motion into a channelized Hotelling observer for the assessment of x-ray angiography systems. Phys Med Biol. 2019 Aug 08;: Authors: Tao A, Fetterly KA Abstract Assessment of x-ray angiography systems is typically performed using stationary task objects with simple geometries such as a disk on a uniform background. However, these methods do not represent realistic imaging conditions in interventional cardiology as anatomy and devices are inherently non-stationary due to cardiac motion. In this work, a novel method using the channelized Hotelling observer (CHO) was used to assess the influence of motion blur on object detectability. A standard CHO model assumes image system stationarity whereby the detectability index d' of a task object is independent of location however, real angiography systems exhibit non-stationarity. While vendor correction gain factors and offset maps are used to compensate for visual non-uniformities, these corrections do not restore stationarity to the images. Methods to accommodate non-stationarity and allow assessment of the influence of motion blur on test object detectability will be presented. The effect of motion blur was quantified with the relative detectability index (r_d'), where the d' for an object when moving with constant linear velocity was compared to a low velocity "pseudo-stationary" condition to account for system non-stationarity. The pseudo-stationa...
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research