Optimizing left anterior oblique (LAO) caudal imaging in coronary angiography using the Taguchi method: A phantom study with clinical verification.

Abstract

The aim of this work tried to optimize the spider view of the coronary angiograph for the clinical diagnosis of cardiac artery disease by cardiologists. A qualified spider view in coronary angiography must be exactly a "quasi-spider" image, which can help to diagnose a lesion in left main coronary artery and related regions. Coronary artery phantom was placed in a 75mm-thick acrylic box to model a 70kg human thorax. Eighteen groups of various combinations of operating factors of the X-ray facility were organized based on a Taguchi analysis. The six factors that govern the imaging quality of X-ray were (A) whether the X-rays emitted through a filter, (B, C) the Left Anterior Oblique (LAO) and Caudal Angulation (CAU) projection angles, (D) X-ray peak voltage (kVp), (E) X-ray pulse duration and current (mAs) and (F) distance between X-ray source and intensifying plate (SID). The obtained X-ray spider view images of each group were graded to determine the optimal settings; X-ray emitted without filter, 70° LAO, 30° CAU, 110kVp, 1.5mAs and 108cm of SID. X-ray imaging quality optimal result was confirmed based on a clinical diagnosis of 43 patients, to prove the effectiveness of this study.