Diagnostic or medical imaging incorporates radiology, nuclear medicine, investigative radiological sciences, endoscopy, medical thermography, medical photography, and microscopy. Diagnostic imaging is a science, and a tool that often is misunderstood. In this resource, which contains 20 facts everyone should know about diagnostic imaging, you may learn that the facts vary depending upon the sources. And, outside the solid fact that some body piercings may be safe to wear during testing, information on this topic often is controversial.
Although the term, “noninvasive,” often is applied to diagnostic imaging because the techniques do not penetrate the skin physically, some procedures are very invasive on the electromagnetic and radiation level. Learn more about safety standards for these processes.
- Radiation Exposure: In 2009, the National Council on Radiation Protections and Measurements (NCRP) reported that Americans were exposed to more than seven times as much ionizing radiation from medical procedures than in the early 1980s. But, the reason behind this increase was primarily a result of the growth in the use of medical imaging procedures, especially computed tomography (CT) and nuclear medicine.
- Exposure Reduction Measures: In 2010, the U.S. Food and Drug Administration (FDA) announced an initiative to reduce unnecessary radiation exposure from three types of medical imaging procedures: computed tomography (CT), nuclear medicine, and fluoroscopy. These quality assurance practices will improve the quality of oversight and promote the safe use of advanced imaging technologies.
- Learning More from Less: Doctors and health facilities are learning that information gained from one magnetic resonance (MR) or CT scan can be used for other information about a patient, lessening the amount of time and money spent on repetitious procedures and increasing safety all around.
- Image Wisely: As a result of safety concerns, the American College of Radiology and the Radiological Society of North America formed the Joint Task Force on Adult Radiation Protection to address concerns about the surge of public exposure to ionizing radiation from medical imaging. This site addresses issues for radiologists, medical physicists, other imaging practitioners, and patients.
- Patient Control Factors: Although this link leads to only one resource, this company — among others — have responded to the FDA idea about patient medical imaging history cards that allow patients to track their amounts of imaging doses over a lifetime. Another free resource [PDF] is shown at Radiology Info’s site.
Mammograms and Controversies
- Ultrasound Backup for Detection: Up to ten percent of breast cancers do not show up on a mammogram, either because they are located in a part of the breast that is difficult to include in the image or they are hidden by normal breast tissue. While ultrasound is not a first choice for detecting breast cancer, if a patient feels a lump that tests negative on a normal mammogram, an ultrasound may be used to diagnose that lump.
- Early Detection: An experienced examiner can feel a lump the size of a small pea. Mammography can find a lump the size of a grain of rice, especially with computer assisted detection tools (CAD).
- Government Intervention: In 2009, The U.S. Preventive Services Task Force advised that women over age 74 should stop all breast cancer screening because the practice lacks evidence of clinical benefit. The group based its recommendations on findings that radiology screening for breast cancer lacks evidence of clinical benefit.
- Controversy Continues: While tests about the effectiveness of breast cancer screening continue through 2010, one conclusion is that a better test is needed. Current screenings offer a 30-percent reduction of breast cancer deaths, while Pap smears result in a 90-percent reduction in cervical cancer deaths. Colorectal screening yields a 60-percent reduction.
- Further Controversy: When Mammography Screening—truth, lies and controversy was published, the book caused controversy among researchers, policymakers, and physicians. Dr. Gøtzsche, the author and director of The Nordic Cochrane Centre, Copenhagen, describes himself as someone who knew little about mammography when, in 1999, he was asked by the Danish Research Council to do an in-depth assessment of all mammography-related research. This book shows that many more women given regular mammograms are treated for breast cancer than the unscreened women, and these treatments themselves may cause fatalities.
- Overdiagnosis: A 2012 report reveals that Norwegian researchers analyzed data from 39,888 women with invasive breast cancer through 2006; over ten years, 7,793 women were diagnosed during the screening program. The results showed that an estimated 15 percent to 25 percent of breast cancers (1,169 to 1,948 women) were over diagnosed. This study adds to an increasing body of evidence that this practice has caused a problem for women — diagnosis of breast cancer that wouldn’t cause symptoms or death.
Other Myths and Realities
- More Over Diagnosis: According to the Centers for Disease Control and Prevention (CDC), over diagnosis is a major concern when screening for any cancer. This is because the screening process may be more likely to detect slow growing cancers or cancers that would not have become symptomatic and therefore never diagnosed. The implication for over diagnosis is that the patients diagnosed with an indolent cancer may end up undergoing an invasive intervention that they would not otherwise need.
- Diagnostic Imaging Doesn’t Increase Health Care Costs: A new analysis of 2010 Medicare claims data shows that spending on medical imaging continues to decline and that Medicare patients are actually receiving fewer imaging procedures, debunking the myth that life-saving diagnostic imaging exams and radiation therapy are increasing health care costs.
- Diagnostic Trends and Affects on Medicare: Imaging growth in Medicare is less than two percent per year. Unlike most other Medicare services, spending on medical imaging is at roughly the same level as in 2004.
- Increased Life Expectancy: A National Bureau of Economic Research study showed that increased use of medical imaging is directly tied to an increase in life expectancy for Americans. And that those who had lesser access to imaging had a smaller increase in life expectancy.
- Discrepancies in Utilization [PDF]: A Radiology Business Management Association (RBMA) survey of freestanding and outpatient imaging centers shows that the national average equipment utilization rate is only 54 percent. The results, which vary by a variety of characteristics, indicate that the present equipment utilization rate assumption of 75 percent is artificially high.
- CT Use Increasing in Emergencies: A recent analysis of national trends in use of CT in the emergency department (ED) concludes the increased use of CT in the ED has been associated with a decline in admissions or transfers after CT use.
- Diagnostic Imaging Cannot Detect Alzheimer’s Disease: There is no blood or imaging test that can be used to diagnose Alzheimer’s disease. Although imaging tests may be used in a battery of other tests to rule out other symptoms, after someone dies, an autopsy can be performed to look for physical markers of Alzheimer’s disease in the brain that cannot be seen with imaging tests.
- Piercings are Permissible During MR: Despite the fear that many healthcare providers harbor that jewelry will fly across the room during a magnetic resonance (MR), most published articles that address MR and piercings show that higher-quality body jewelry containing LVM 316 or 316L stainless steel, titanium, or niobium has been found to be safe even if worn during an MR examination.
- An MRI Can Be Used in Court: Although one company has been trying to use the magnetic resonance imaging process as a lie-detector test, this process is not as reliable as many hoped. But, in November 2009, MRI brain scans were used in court for the first time. During a sentencing hearing in Illinois for the convicted multiple murderer Brian Dugan, defense attorneys used MRI scans that showed Dugan had abnormal brain functioning.