Magnetic resonance. Principles and applications.
Magnetic resonance is a unique, noninvasive imaging modality which allows direct, multiplanar imaging and the possibility of obtaining biochemical information in vivo. Presently, MR appears most applicable to the evaluation of central nervous system abnormalities. The high sensitivity of MR in the evaluation of intracranial pathology suggests that it may eventually replace CT for many suspected diseases, if future investigations are able to improve its specificity. As previously noted, MR may be more diagnostic than other radiologic studies in the evaluation of suspected Chiari malformation, syringomyelia, congenital abnormalities, tumors of the spinal axis, and disc space infection. In the chest, MR appears to be more accurate than CT in the determination of the extent of mediastinal tumor, but at present cannot replace CT because of the lack of experience in imaging parenchymal nodules and benign diseases. MR of the breast is promising, but the size of the lesion may prove to be a limiting factor with magnetic field strengths commonly being utilized. There are inherent difficulties in the evaluation of cardiac disease with MR, but it offers a noninvasive method of investigating congenital heart disease and may provide valuable information in suspected myocardial ischemia and altered cardiac function. MR provides a new method of evaluating the vascular system, both in terms of providing anatomic information on large and medium-sized vessels and flow analysis. In the abdomen, MR appears to be most sensitive in the evaluation of suspected hepatic masses, but as with the brain, greater specificity will be needed to replace CT. At the present time, MR offers no distinct advantage over conventional imaging modalities in the evaluation of pancreatic disease, it maybe more accurate than CT in the staging of renal cell carcinoma. Larger studies are needed to determine the role of MR in the investigation of retroperitoneal adenopathy and adrenal abnormalities. In the pelvis, MR offers the hope of earlier diagnosis of prostatic carcinoma and may replace CT for staging of prostatic carcinoma and transitional cell carcinoma of the bladder. Limited MR experience with benign disease of the female pelvis suggests that it is currently more accurately evaluated with ultrasound. MR appears to be highly sensitive and specific for the diagnosis of avascular necrosis and may provide an early clue in suspected osteomyelitis. Finally, in vivo MR spectroscopy may provide unique metabolic information that was unobtainable prior to the advent of magnetic resonance, if this proves to be technically feasible.
D001847:Bone Diseases / Q000175:diagnosis; D001927:Brain Diseases / Q000175:diagnosis; D001941:Breast Diseases / Q000175:diagnosis; D005260:Female; D005831:Genital Diseases, Female / Q000175:diagnosis; D005832:Genital Diseases, Male / Q000175:diagnosis; D006258:Head and Neck Neoplasms / Q000175:diagnosis; D006331:Heart Diseases / Q000175:diagnosis; D006801:Humans; D008107:Liver Diseases / Q000175:diagnosis; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D010182:Pancreatic Diseases / Q000175:diagnosis; D055585:Physical Phenomena; D010825:Physics; D013122:Spinal Diseases / Q000175:diagnosis; D013896:Thoracic Diseases / Q000175:diagnosis; D014057:Tomography, X-Ray Computed; D014570:Urologic Diseases / Q000175:diagnosis; D014652:Vascular Diseases / Q000175:diagnosis