Full-body CT scan
- For full-body scanners found in airport-security, see Full body scanner.
A "'full-body scan is a scan of the patient's entire body as part of the diagnosis or treatment of illnesses. If computed tomography (CAT) scan technology is used, it is known as a full-body CT scan, though many medical imaging technologies can perform full-body scans (see box on bottom of page).
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[edit] Use in preventive screening
A full-body scan has the potential to identify disease (e.g. cancer) in early stages, and early identification can improve the success of curative efforts. Controversy arises from the use of full-body scans in the screening of patients who have no signs or [symptom]]s suggestive of a disease.[1] As with any test that screens for disease, the risks of full-body CT scans need to be weighed against the benefit of identifying a treatable disease at an early stage.[2]
[edit] Controversy
[edit] Health risks
- Compared to most other diagnostic imaging procedures, CT scans result in relatively high radiation exposure. This exposure may be associated with a very small increase in cancer risk. The question is whether that risk is outweighed by the benefits of diagnosis and therapy[3]
[edit] Diagnosis benefits
- Allows a transparent view of the body, which normally is not transparent. Many possible malignancies are discovered with a full-body scan, but these are almost always benign.[4][5] These may not be related to any disease, and may be benign growths, scar tissue, or the remnants of previous infections. CT scanning for other reasons sometimes identifies these "incidentalomas".
[edit] Expense
These procedures are relatively expensive. Possibly high cost: At a cost of US$600 to $3000, full-body scans are expensive, and are rarely covered by insurance.[6][7] However, in December 2007, the IRS stated that full-body scans qualify as deductible medical expenses, without a doctor's referral. This will likely lead employer-sponsored, flexible-spending plans to make the cost of the scans eligible for reimbursement.[8]
[edit] False positives
Low rate of finding disease.[4][5] Confusion regarding "incidentalomas" (see above): It is uncertain how to treat some of them, or if treatment is even necessary.[9]
- May not be able to detect colors, unlike for example a colonoscopy.
[edit] Alternatives
[edit] Partial-body scans
Other CT scans may be used in screening for disease in high risk groups. These scans are more localized and are identical to those used in the course of treating a disease, the only difference being that these scans are done before any disease is found.
Low-dose CT scanning of the lungs may be done to screen for lung cancer, but it has showed varied success.[10][11] CT colography, or virtual colonoscopy is a CT scan that looks for polyps that may develop into colon cancer. It has shown detection rates for polyps of size greater or equal to 8 mm that are comparable to traditional or "optical" colonoscopy. One of the downsides of imaging is that although they provide comparable detection rates, they have no inherent capability of treatment. For example, if polyps are found on virtual colonoscopy the next step is to perform a traditional colonoscopy to remove the polyps; however the initial diagnosis is significantly less invasive.[12]
Other types of scans include heart, brain, bone density, angiogram and carotid artery.[13][14]
Magnetic resonance imaging (MRI) scans are associated with a lesser radiation risk than CT scans, and are being evaluated for their use in screening.[15]
[edit] In popular culture
- In the episode "Role Model" of the TV show House the lead character Dr. Gregory House refers to full-body scans as "useless" because, in his words, "you could probably scan every one of us and find fifty doo-dads that look like cancer". This issue was revisited in a later episode, "The Social Contract", where a full-body scan was successfully used to identify a tumor and diagnose Doege-Potter syndrome. Then in "Black Hole", House orders a full-body scan over the objections of his team, followed by a different scan on a pineal gland.
- In the Scrubs episode "My Fault", Dr. Kelso decides to offer full-body scans at Sacred Heart Hospital, despite the objections of Dr. Cox. This offer is taken by Harvey Corman, who is an "admittedly frugal hypochondriac".
[edit] See also
- Full body scanner
- Medical imaging
- Backscatter X-ray (for security scanning)
- Millimeter wave scanner (for security scanning)
[edit] References
- ^ "U.S Food and Drug Administration Whole body CT scans, DHHS Publication No: (FDA) 03-0001". March 2003. http://www.fda.gov/cdrh/ct/ctscansbro.html. Retrieved August 30, 2006.
- ^ MacLean CD (January 1996). "Principles of cancer screening". Med Clin North Am 80 (1): 1–14. doi:10.1016/S0025-7125(05)70423-5. PMID 8569290.
- ^ Full-Body CT Scans - What You Need to Know. Fda.gov. Retrieved on 2010-09-26.
- ^ a b Brant-Zawadzki MN (November 2005). "The role of computed tomography in screening for cancer.". Eur Radiol 15 Suppl 4: 52–54. PMID 16479647.
- ^ a b Berlin L (February 2003). "Potential legal ramifications of whole-body CT screening: taking a pesek into Pandora's box.". AJR Am J Roentgenol 180 (2): 317–322. PMID 12540423.
- ^ Meyer M. (October 2002). "Behind the Body Scan Craze". http://www.aarp.org/bulletin/yourhealth/a2003-08-01-bodyscan.html?print=yes. Retrieved August 30, 2006.
- ^ "Whole-body Scans More Marketing Than Science, Say Medical Physicists. American Institute of Physics.". 2002-08-26. Archived from the original on May 1, 2006. http://web.archive.org/web/20060501223224/http://www.aip.org/isns/reports/2002/052.html. Retrieved August 30, 2006.
- ^ "Diagnosis? It's Deductible". http://turbotax.intuit.com/support/kb/deductions-and-credits/deductions-and-credits/5214.html.
- ^ Grumbach MM, Biller BM, Braunstein GD, Campbell KK, Carney JA, Godley PA, Harris EL, Lee JK, Oertel YC, Posner MC, Schlechte JA, Wieand HS (March 2003). "Management of the clinically inapparent adrenal mass ("incidentaloma")". Ann Intern Med. 138 (5): 424–429. PMID 12614096.
- ^ Diederich S, Wormanns D. (August 2004). "Impact of low-dose CT on lung cancer screening". Lung Cancer 45 suppl 2: 13–19. doi:10.1016/j.lungcan.2004.07.997. PMID 15552777.
- ^ Kashiwabara K, Kohshi S. (September 2006). "Outcome in patients with lung cancer invisible on chest roentgenograms but detected only by helical computed tomography.". Respirology 11 (5): 592–597. doi:10.1111/j.1440-1843.2006.00903.x. PMID 16916332.
- ^ Pickhardt PJ, Choi JR, Hwang I, Butler JA, Puckett ML, Hildebrandt HA, Wong RK, Nugent PA, Mysliwiec PA, Schindler WR. (March 2003). "Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults.". New England Journal of Medicine 349 (23): 2191–2200. doi:10.1056/NEJMoa031618. PMID 14657426.
- ^ Frequently Asked Questions (FAQ's) on Body Scans, Heart Scans, Lung Scans, Virtual Colonoscopy. Scandirectory.com (2007-06-12). Retrieved on 2010-09-26.
- ^ Virtual Colonoscopy effective in finding most poly. ScanDirectory. Retrieved on 2010-09-26.
- ^ Lauenstein TC, Semelka RC. (August 2006). "Emerging techniques: Whole-body screening and staging with MRI.". J Magn Reson Imaging 24 (3): 489–498. doi:10.1002/jmri.20666. PMID 16888774.
