Quantitative and qualitative analysis and interpretation of CT perfusion imaging

Abstract

Coronary artery disease (CAD) remains the leading cause of death in the United States. Rest and stress myocardial perfusion imaging has an important role in the non-invasive risk stratification of patients with CAD. However, diagnostic accuracies have been limited, which has led to the development of several myocardial perfusion imaging techniques. Among them, myocardial computed tomography perfusion imaging (CTP) is especially interesting as it has the unique capability of providing anatomic- as well as coronary stenosis-related functional data when combined with computed tomography angiography (CTA). The primary aim of this article is to review the qualitative, semi-quantitative, and quantitative analysis approaches to CTP imaging. In doing so, we will describe the image data required for each analysis and discuss the advantages and disadvantages of each approach.

2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS Guideline for the Diagnosis and Management of Patients With Stable Ischemic Heart Disease

“…In addition, newer scanning techniques have allowed assessment of perfusion and FFR by CCTA alone, in addition to coronary anatomy. [195][196][197][198][199][200][201] Notably, these combined assessments allow for a fused image in which the physiological assessment of flow is coupled with the anatomic extent and severity of CAD and also provides information on plaque composition and arterial remodeling. Limited evidence is available on hybrid imaging, although several reports have reported prognostic accuracy for cardiac events with both ischemic and anatomic markers.…”

Myocardial Blood Flow Quantification for Evaluation of Coronary Artery Disease by Positron Emission Tomography, Cardiac Magnetic Resonance Imaging, and Computed Tomography

“…Investigators demonstrated a strong correlation of EBCT-derived myocardial perfusion metrics with microsphere-derived MBF [57-59]. Dynamic EBCT was further validated in an animal study and in healthy volunteers with maximal vasodilatation and at rest [60].…”

Computer-Assisted Myocardial Perfusion Assessment

“…The window and level are initially set to 300 and 150, respectively, based on experience and on typical values described in the literature (e.g., Valdiviezo et al [8] and Cury et al [13]) and considering that common starting values should be used for all exams contributing to similar analysis conditions and criteria. If desired, window and level can be adjusted at any time.…”

“…While some efforts are being directed to the development of such methods [6,7] for quantitative myocardial perfusion assessment, to the best of our knowledge, none of those works considered providing enhanced tools to support the clinician during visual assessment. Visual interpretation of CTP images is still of paramount importance [8], given the common presence of image artefacts [5,9] which hinder a good performance of automatic methods (among other factors). Introducing interactive tools to support visual perfusion assessment might, for example, reduce the required clinician effort to correctly assign perfusion deficit to a specific myocardial segment, shortening analysis time and improving confidence levels.…”