Cardiac MR imaging: a guide for the beginner.

The complex motion of the heart during contraction is a serious challenge to the diagnostic radiologist and to the capabilities of the magnetic resonance (MR) imaging unit itself, but electrocardiographic (ECG) gating "stops" motion and thus allows acquisition of diagnostic-quality images. Attention to placement of chest-wall ECG electrodes and the course of ECG leads from the patient will maximize the quality of the gating signal and result in better-quality images. Before commencing the MR imaging examination, the clinical questions for the examination must be identified so that a clinical protocol can be applied to acquire relevant morphologic and physiologic data. In addition to the standard orthogonal views (axial, coronal, and sagittal), oblique and complex sections parallel and orthogonal to intrinsic cardiac axes may be necessary to portray the relevant anatomy to best advantage. Construction of these views requires an understanding of basic normal and pathologic cardiac anatomy. If care is taken in the planning and execution of the MR imaging examination, the radiologist will be able to exploit this exciting technology to its full noninvasive potential.