Cardiac magnetic resonance cine image analysis

Abstract

Cine MRI imaging is a main component of almost every cardiovascular magnetic resonance (CMR) exam. Typically, a stack of parallel short-axis (SAX) images covering the heart is acquired along with four-chamber, two-chamber, and sometimes three-chamber views. Ventricular contours drawn on the cine images during postprocessing are used to generate measures of global heart function, for example, volumes, mass, and ejection fraction (EF). However, recent efforts have been made to exploit cine images for evaluating regional heart function, for example, measuring myocardial strain and detecting wall motion abnormalities. It should be noted that while the cine images lack the tagging pattern that is used for tracking myocardial deformation in the MRI tagged images, useful information can still be obtained from tracking wall motion during the cardiac cycle. Furthermore, myocardial radial thickening is easier to measure from the cine nontagged images because the tagging pattern sparsely samples the myocardium in the radial direction. Therefore, many image processing and analysis techniques have been developed for evaluating myocardial deformation during the cardiac cycle based on processing the cine images, which is the topic of this chapter. It should be noted that in this chapter we do not address methods for analyzing the cine images using the recently developed feature-tracking techniques. These techniques are covered in detail in the next chapter.