Full-body scan

Full-body scan, also known as a full-body CT scan, involves a CT scan of the patient's entire body to support the diagnosis and treatment of specific illnesses.

History and overview

CT scans were first used in medicine in the 1970s,cite journal | author = Hounsfield GN. | year = 1976 | month = Sept | title = Historical notes on computerized axial tomography | journal = J Can Assoc Radiol | volume = 27 | issue = 3 | pages = 135–142 | pmid = 789383 ] and they now play an important role in diagnosis in medicine. Controversy arises from the use of CT scans in the screening of patients who have not been diagnosed with a disease, or who do not have symptoms suggestive of a disease,cite web| url = http://www.fda.gov/cdrh/ct/ctscansbro.html| title = U.S Food and Drug Administration Whole body CT scans, DHHS Publication No: (FDA) 03-0001| accessdate = August 30| accessyear = 2006| date = | year = 2003| month = March] due to the low rate of finding disease, and the inconclusiveness of the cause of abnormalities seen.cite journal | author = Brant-Zawadzki MN | year = 2005 | month = Nov | title = The role of computed tomography in screening for cancer. | journal = Eur Radiol | volume = 15 Suppl 4 | pages = 52–54|pmid = 16479647 ] cite journal | author = Berlin L | year = 2003 | month = Feb | title = Potential legal ramifications of whole-body CT screening: taking a peek into Pandora's box. | journal = AJR Am J Roentgenol | volume = 180 | issue = 2 | pages = 317–322 | pmid = 12540423 ]

As with any test that screens for disease, the risks of full-body CT scans, (including radiation, incidental or wrong diagnosis, and a false sense of security in a test with error), need to be weighed against the benefit of identifying a treatable disease at an early stage.cite journal | author = MacLean CD | year = 1996 | month = Jan | title = Principles of cancer screening | journal = Med Clin North Am | volume = 80 | issue = 1 | pages = 1–14 | pmid = 8569290 | doi = 10.1016/S0025-7125(05)70423-5] One of the risks of a full body CT scan is the relatively high doses of radiation.cite journal|author = McCauley TR | year = 2003 | month = Feb | title = Radiation risk of screening CT | journal = AJR Am J Roentgenol | volume = 180 | issue = 2 | pages = 540–541| pmid = 12540469] Conventional CT scanners may expose patients to 10 mSv of radiation, or over a hundred times that of a chest x-ray.cite web| url = http://www.radiologyinfo.org/en/safety/index.cfm?pg=sfty_xray#3| title = Radiologyinfo: Safety Radiation Exposure in X-ray Examinations | accessdate = August 30| accessyear = 2006| date = | year = | month = ] However, the radiation risk of CT scanners used for screening may be less than this, and depends upon the mathematical model used for calculation.cite journal | author = Prokop M | year = 2005 | month = Nov | title = Cancer screening with CT: dose controversy. | journal = Eur Radiol | volume = 15 Suppl 4 | pages = 55–61 |pmid = 16479648 ] Additional risks include the possible identification of incidental abnormalities of unclear significance. 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", and it is uncertain how to treat some of them.cite journal |author = Grumbach MM, Biller BM, Braunstein GD, Campbell KK, Carney JA, Godley PA, Harris EL, Lee JK, Oertel YC, Posner MC, Schlechte JA, Wieand HS | year = 2003 | month = Mar | title = Management of the clinically inapparent adrenal mass ("incidentaloma") | journal = Ann Intern Med. | volume = 138 | issue = 5 | pages = 424–429 | pmid = 12614096] This may lead to further unnecessary testing, which may be invasive.

Cost is an additional disadvantage; at a cost of US$600 to $3000 full-body scans are expensive, and are rarely covered by insurance. [cite web | url = http://www.aarp.org/bulletin/yourhealth/a2003-08-01-bodyscan.html?print=yes | title = Behind the Body Scan Craze | author = Meyer M. | accessdate = August 30| accessyear = 2006| date = | year = 2002| month = October] [cite web | url = http://www.aip.org/isns/reports/2002/052.html | title = Whole-body Scans More Marketing Than Science, Say Medical Physicists. American Institute of Physics. | date = 2002-08-26 | accessdate = August 30| accessyear = 2006] 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. [cite web | url = http://turbotax.intuit.com/support/kb/deductions-and-credits/deductions-and-credits/5214.html | title = Diagnosis? It's Deductible]

Other 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.cite journal | author = Diederich S, Wormanns D. | year = 2004 | month = Aug | title = Impact of low-dose CT on lung cancer screening | journal = Lung Cancer | volume = 45 suppl 2 | pages = 13–19 | pmid = 15552777 | doi = 10.1016/j.lungcan.2004.07.997] cite journal | author = Kashiwabara K, Kohshi S. | year = 2006 | month = Sep | title = Outcome in patients with lung cancer invisible on chest roentgenograms but detected only by helical computed tomography. | journal = Respirology | volume = 11 | issue = 5 | pages = 592–597 | pmid = 16916332 | doi = 10.1111/j.1440-1843.2006.00903.x] 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.cite journal | author = Pickhardt PJ, Choi JR, Hwang I, Butler JA, Puckett ML, Hildebrandt HA, Wong RK, Nugent PA, Mysliwiec PA, Schindler WR. | year = 2003 | month = Mar | title = Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults. | journal = New England Journal of Medicine | volume = 349 | issue = 23 | pages = 2191–2200 | pmid = 14657426 | doi = 10.1056/NEJMoa031618]

Other types of scans include Heart, Brain, Bone density, Angiogram, Carotid artery. [http://www.scandirectory.com/content/faq.asp#faq10] [http://www.scandirectory.com/news/news_details.asp?ID=67]

Magnetic resonance imaging (MRI) scans are associated with a lesser radiation risk than CT scans, and are being evaluated for their use in screening.cite journal | author = Lauenstein TC, Semelka RC. | year = 2006 | month = August | title = Emerging techniques: Whole-body screening and staging with MRI. | journal = J Magn Reson Imaging | volume = 24 | issue = 3 | pages = 489–498 | pmid = 16888774 | doi = 10.1002/jmri.20666 ]

ee also

* Security scan
* Medical imaging

References