Principles and techniques of cardiac imaging

Cardiac MRI is a relatively new modality in the morphological and functional evaluation of the heart. Its ability in the evaluation of many cardiac diseases is widely recognized. It provides clinically relevant information in: a) the evaluation of anatomy and function (if question remains after echocardiography or X-ray angiography); b) in complex malformations and in follow up studies when echocardiography does not provide complete information; c) in the evaluation of the apex region, epicardial borders, right ventricle and pericardial thickening. Cardiac MRI is considered a promising modality still under investigation for the evaluation of the myocardial perfusion and coronary artery diseases. Technical aspects. The evaluation of the heart is quite different from that of the other organs: the ECG triggering of the acquisition is essential, functional evaluation is mandatory and the evaluation is performed in oblique planes. The morphological examination is obtained using ECG gated multiphase-multislice sequences which take from 4-5 minutes of the standard SE acquisition time to one second of the fastest black blood half Fourier single-shot FSE sequence. Functional evaluation is performed using breath hold Fast Gradient echo acquisition with very short TR/TE and K-space segmentation useful to obtain Cine imaging with up to 60 phases per breath-hold. The standard examination is performed on long and short axis planes but different orientation may be useful in different cases. This technique is considered the best modality to evaluate cardiac volumes and mass providing direct non geometric analysis of the ventricles. Learning Objectives: 1. To comprehend the indications for Cardiac MRI in the clinical setting. 2. To understand the study technique of the heart (sequences and slice orientation). 3. To become familiar with the normal anatomy. 4. To learn the parameters of the normal cardiac function