Coronary blood flow quantification from X-ray angiography

Coronary angiography provides anatomical information about the epicardial coronary arteries but is poor at evaluating coronary microcirculation. Coronary blood flow (CBF) measurements would be a superior tool for evaluation of coronary circulation but are difficult to perform in cardiac catheterisation laboratory in real time. A workflow for quantification of CBF using X-ray signal intensity analysis of coronary angiogram images was developed at the University of Leeds using a custom-built computer software – herein referred to as the ‘X-ray Blood Flow’ (XBF) method. A bench study and two human pilot studies were conducted to test the feasibility of quantification of CBF using the XBF method. The bench study utilised a cardiac phantom that simulated CBF. The first human validation study compared XBF flow to CBF measured by continuous thermodilution technique. The second human study in ST elevation myocardial infarction (STEMI) patients study sought to establish the safety and utility of the XBF method by correlating the XBF flow and resistance measurements after primary percutaneous intervention to infarct parameters from cardiovascular magnetic resonance (CMR) imaging.