Surface/specialty coil devices and gating techniques in magnetic resonance imaging

Surface and other specialty coil devices and gating techniques are used in conjunction with MRI procedures to enhance image quality. Surface coils improve image quality by virtue of the improved signal-to-noise ratio, which results in better anatomic detail and tissue contrast. These coils may be advantageous for many kinds of imaging procedures, particularly for small structures that require greater spatial resolution. Although safety is not considered an issue, certain precautions must be taken to avoid skin burns. Gating techniques have been used to eliminate movement artifacts and associated image blurring. Cardiac-gated imaging has enabled the acquisition of high resolution diagnostic quality cardiac images with conventional MRI. Studies of gated cardiac imaging have demonstrated the technical capacity of MR scanning for evaluating ischemic heart disease, cardiomyopathy, pericardial diseases, intracardiac and paracardiac masses, thoracic-aortic diseases, and congenital heart disease. Cardiac imaging also has been found valuable in reducing motion artifacts in MRI of the chest, brain, spine, and liver. Gated imaging studies demonstrated that MRI respiratory gating improves thoracic and abdominal imaging; however, inherent time delays limit its usefulness. No patient-related risks appear to be involved when gating procedures are used appropriately. The use of gating techniques may add substantial time to the imaging procedure. Surface coil and gated MRI techniques have been found to be better than the conventional MRI studies when they improve the quality of the exam and its diagnostic capabilities.