Enhanced MRI is based on the plain MRI scan and uses intravenous contrast to diagnose disease by taking advantage of the difference in blood supply characteristics between the lesion and normal tissue, the difference in blood source, and the difference in signal intensity generated, and it also scans several more sequences than the plain MRI. Enhanced MRI is mainly used for lesions that are detected by normal MRI but the nature of the lesion is not clear, or for other examinations or tests that suggest an occupying lesion that is not shown by normal MRI. However, for enhanced MRI, an allergy test of the contrast agent should be performed before the examination and only if the patient is not allergic.