MRI (Magnetic Resonance Imaging)
MRI examinations are very important in detection, diagnosis, treatment planning and follow-up of many diseases. For instance, the images can reveal the limits of a tumor, contributing to a more precise surgery and radiation therapy. MRI has become a routine method during the last decades, and the method is still in rapid development. This modality is often superior to other imaging techniques. MRI has replaced several invasive modes of examination and thereby reduced the discomfort and the risk of complications for many patients.
In patients with prolonged back pain, it is important to see if the pain is caused by pressure on a nerve or on the spinal cord. MRI examinations have replaced previous methods.
Today, MRI is used to examine all organs of the body. Detailed MR images allow physicians to better evaluate various parts of the body and determine the presence of certain diseases that may not be assessed adequately with other imaging methods such as xray, ultrasound or computed tomography (also called CT or CAT scanning). Examination with MRI is the best for diagnosis and follow-up of many diseases. Another example is early demonstration of encephalitis.
Magnetic Resonance Imaging (MRI) uses radiofrequency waves and a strong magnetic field rather than x-rays to provide remarkably clear and detailed pictures of internal organs and tissues. The technique has proven very valuable for the diagnosis of a broad range of pathologic conditions in all parts of the body, including cancer, heart and vascular disease, stroke, and joint and musculoskeletal disorders. MRI requires specialized equipment and expertise and allows evaluation of some body structures that may not be as visible with other imaging methods.
Because MRI can give such clear pictures of soft-tissue structures near and around bones, it is the most sensitive exam for spinal and joint problems. MRI is widely used to diagnose sports-related injuries, especially those affecting the knee, shoulder, hip, elbow, and wrist. The images allow the physician to see even very small tears and injuries to ligaments and muscles.
In addition, MRI of the heart, aorta, coronary arteries, and blood vessels is a fast, noninvasive tool for diagnosing coronary artery disease and heart problems. Physicians can examine the size and thickness of the chambers of the heart, and determine the extent of damage caused by a heart attack or progressive heart disease.
Organs of the chest and abdomen including the lungs, liver, kidney, spleen, pancreas, and abdominal vessels can also be examined in high detail with MRI, enabling the diagnosis and evaluation of tumors and functional disorders. MRI is growing in popularity as an alternative to traditional x-ray mammography in the early diagnosis of breast cancer. We, at California Radiology, are happy to announce that we have a specially designed equipment to make MRI of the breast as easy as possible. Because no radiation exposure is involved, MRI is often the preferred diagnostic tool for examination of the male and female reproductive systems, pelvis and hips, and the bladder.
How should one prepare for the procedure?
Because the strong magnetic field used for MRI will pull on any metal object implanted in the body, MRI staff will ask whether you have a prosthetic hip, heart pacemaker (or artificial heart valve), or any metal plates, pins, screws, or surgical staples in your body. Tattoos and permanent eyeliner may also create a problem. You will be asked if you have ever had a bullet or shrapnel in your body, or ever worked with metal. If there is any question of metal fragments, you may be asked to have an x-ray that will detect any such metal objects. Tooth fillings usually are not affected by the magnetic field, but they may distort images of the facial area or brain, so the radiologist should be aware of them. The same is true of braces, which may make it hard to “tune” the MRI unit to your body. You will be asked to remove anything that might degrade MRI images, including hairpins, jewelry, eyeglasses, hearing aids, and any removable dental work.
What are the benefits of MRI or MRA?
Exposure to radiation is avoided.
Images are clearer and more detailed than with other imaging methods.
Identifies the causes of pain, swelling, and bleeding so that appropriate treatment can begin.
The contrast material is less likely to produce an allergic reaction than the iodine-based materials used for conventional x-rays and CT scanning.
MRI enables the detection of abnormalities that might be obscured by bone tissue with other imaging methods.
MRI angiography provides detailed images of blood vessels in the brain without the need to inject contrast material.
MRA (MAGNETIC RESONANCE ANGIOGRAM)
Magnetic Resonance Angiography (MRA) is a special type of magnetic resonance imaging (MRI) test designed to evaluate arteries, veins, and the flowing blood within them. During an MRI examination, the patient is placed inside the opening of a very large magnet. Radiofrequency pulses are used within the magnetic field to generate detailed images of internal organs. No X-rays or ionizing radiation of any kind is necessary for an MRI exam. During an MRA exam, special types of pulses are used to create pictures of flowing blood and blood vessels. MRA is performed without need for catheters, and in many cases without need for any type of dyes or contrast injections. Sometimes, to produce exceptionally detailed pictures, MRI dye (gadolinium) is injected into a vein in the arm.
MRA is performed on the arteries of the neck and brain to test for any narrowing or plaque buildup that could lead to stroke, or for any weakening or ballooning of the arteries (aneurysms) that could lead to bleeding around the brain. MRA is performed on the arteries to the kidneys to test for narrowing that could lead to hypertension (high blood pressure). MRA is performed on the pelvis and legs to look for narrowing that could lead to painful walking or nonhealing ulcers or to look for blood clots in the veins.