At one time doctors relied heavily on plain films or x-rays for information concerning the inner workings of the body. Today more sophisticated equipment reveals far more about the body's interior and uses less harmful methods. Tests such as the CT scan, PET scan, myelogram, ultrasound, bone scan and MRI have advanced the diagnostic capabilities of the medical field. This new diagnostic technology can confuse the layman, who may wonder why her doctor has chosen to order an MRI, for instance, rather than a bone scan. Understanding what these two machines can and cannot do may answer some questions.
Definitions
The bone scan is a nuclear medicine diagnostic tool that works by injecting a radioactive material into the patient and then watching the screen for any inconsistencies along the length of the bones. These differences, called “hot spots”, signal possible malignancy. This test looks particularly at metabolic changes in the bones. It does not evaluate structural conditions such as fractures. The MRI or magnetic resonance imaging holds first place as the most effective diagnostic imaging available today, according to Imagimed.com. Employed to find infections, tumors and other maladies, the MRI uses safe magnetic imaging without the radioactive contrasts associated with scanners.
Uses
While helpful in diagnosing a suspected tumor, infection or fracture, the bone scan has limitations. Spineuniverse.com reports that it has poor spatial resolution in areas such as the spine, so the MRI is a better choice here. The scan studies bones only. If a bone scan is positive for disease or injury, a definitive diagnosis needs to come from a follow-up MRI or CT scan. Besides its utility for bony structures, the MRI can diagnose problems in the brain, head, neck, chest, spine, pelvis, muscles, joints and abdomen.
Conditions
The bone scan picks up on abnormalities. These “hot spots” suggest possible diagnoses, such as metastasis to bone tissue of primary cancers of the breast, lungs, prostate etc. Because they can help with staging primary cancer in an organ distant from the bone, oncologists choose this test most often. Bone scans also prove reliable as a first step screening for many suspected conditions and can help doctors determine whether further tests are needed.
Imagimed.com reports that the MRI can help to evaluate a vast list of conditions. Briefly, some common uses include the diagnosis of stroke, heart attack, nervous system diseases such as multiple sclerosis, seizure disorders and primary tumors of the nervous system, hydrocephalus and brain malformations, as well as blood vessel malformations and various infections, inflammations and tumors in many parts of the body. The MRI also helps diagnose sciatica, herniated disc, spinal stenosis, various forms of paralysis, spinal alignment abnormalities and bone infections. It can detect pelvic masses like uterine fibroids, endometriosis, ovarian masses, diverticulosis, aortic aneurysms and dissections.
Considerations
Obviously, the MRI covers more diagnostic ground than the bone scan. In addition, the MRI does not require the invasive technique of injecting radioactive material into the patient. The broad spectrum of conditions that the MRI can diagnose makes it a far more useful tool than the bone scan. So why use the bone scan at all? The biggest reason is cost.
Costs
On average, a bone scan costs between $200 and $600 in 2010, according to Buzzle.com. CompareMRIcost.com reports that the MRI can cost from $1600 to $3600, the higher end charged in larger U.S. cities. Then insurance coverage comes into consideration. Even if you have insurance, you cannot ask for an MRI if a bone scan would prove useful. Some medical insurance policies don't cover an MRI at all while some do so only for certain conditions.
Recommendations
Your best course of action if you need one of these studies includes discussing your options with your physician and calling your insurance company to ask about coverage before you take the test. Keep in mind that other diagnostic tests such as the CT scan and ultrasound fall somewhere between these two in cost and effectiveness. Your doctor will undoubtedly order the test that gives him the most accurate and useful results for the least money.
Member Comments