Editing CT scan (section)

== Advantages ==
CT scanning has several advantages over traditional [[Plane (mathematics)|two-dimensional]] medical [[radiography]]. First, CT eliminates the superimposition of images of structures outside the area of interest.<ref>{{Cite book |last1=Mikla |first1=Victor I. |url=https://books.google.com/books?id=Y81JrnVA_5sC&q=ct+scan+removes+superimposition&pg=PA37 |title=Medical Imaging Technology |last2=Mikla |first2=Victor V. |date=2013-08-23 |publisher=Elsevier |isbn=978-0-12-417036-0 |page=37}}</ref> Second, CT scans have greater [[image resolution]], enabling examination of finer details. CT can distinguish between [[tissue (biology)|tissues]] that differ in [[Radiodensity| radiographic density]] by 1% or less.<ref>{{Cite book |url=https://books.google.com/books?id=rOppAAAAMAAJ&q=CT+can+distinguish+between+tissue |title=Radiology for the Dental Professional |publisher=Elsevier Mosby |year=2008 |isbn=978-0-323-03071-7 |pages=337}}</ref> Third, CT scanning enables multiplanar reformatted imaging: scan data can be visualized in the [[transverse plane|transverse (or axial)]], [[Coronal plane|coronal]], or [[Sagittal plane|sagittal]] plane, depending on the diagnostic task.<ref>{{Cite book |last=Pasipoularides |first=Ares |url=https://books.google.com/books?id=eMKqdIvxEmQC&q=ct+scan+enables+multiple+plane+reformatting&pg=PA595 |title=Heart's Vortex: Intracardiac Blood Flow Phenomena |date=November 2009 |publisher=PMPH-USA |isbn=978-1-60795-033-2 |pages=595}}</ref>

The improved resolution of CT has permitted the development of new investigations. For example, CT [[angiography]] avoids the invasive insertion of a [[catheter]]. CT scanning can perform a [[virtual colonoscopy]] with greater accuracy and less discomfort for the patient than a traditional [[colonoscopy]].<ref name="Heiken">{{Cite journal |last1=Heiken |first1=JP |last2=Peterson CM |last3=Menias CO |date=November 2005 |title=Virtual colonoscopy for colorectal cancer screening: current status: Wednesday 5 October 2005, 14:00–16:00 |journal=Cancer Imaging |publisher=International Cancer Imaging Society |volume=5 |issue=Spec No A |pages=S133–S139 |doi=10.1102/1470-7330.2005.0108 |pmc=1665314 |pmid=16361129}}</ref><ref name="pmid16106357">{{Cite journal |last1=Bielen DJ |last2=Bosmans HT |last3=De Wever LL |last4=Maes |first4=Frederik |last5=Tejpar |first5=Sabine |last6=Vanbeckevoort |first6=Dirk |last7=Marchal |first7=Guy J.F. |date=September 2005 |title=Clinical validation of high-resolution fast spin-echo MR colonography after colon distention with air |journal=J Magn Reson Imaging |volume=22 |issue=3 |pages=400–5 |doi=10.1002/jmri.20397 |pmid=16106357 |doi-access=free |s2cid=22167728}}</ref> Virtual colonography is far more accurate than a [[barium enema]] for detection of tumors and uses a lower radiation dose.<ref>{{Cite web |title=CT Colonography |url=https://www.radiologyinfo.org/en/info.cfm?pg=ct_colo |website=Radiologyinfo.org}}</ref>

CT is a moderate-to-high [[radiation]] diagnostic technique. The radiation dose for a particular examination depends on multiple factors: volume scanned, patient build, number and type of scan protocol, and desired resolution and image quality.<ref>{{Cite journal |vauthors=Žabić S, Wang Q, Morton T, Brown KM |date=March 2013 |title=A low dose simulation tool for CT systems with energy integrating detectors |journal=Medical Physics |volume=40 |issue=3 |pages=031102 |bibcode=2013MedPh..40c1102Z |doi=10.1118/1.4789628 |pmid=23464282}}</ref> Two helical CT scanning parameters, tube current and pitch, can be adjusted easily and have a profound effect on radiation. CT scanning is more accurate than two-dimensional radiographs in evaluating anterior interbody fusion, although they may still over-read the extent of fusion.<ref>Brian R. Subach M.D., F.A.C.S et al.[http://www.spinemd.com/publications/articles/reliability-and-accuracy-of-fine-cut-computed-tomography-scans-to-determine-the-status-of-anterior-interbody-usions-with-metallic-cages "Reliability and accuracy of fine-cut computed tomography scans to determine the status of anterior interbody fusions with metallic cages"] {{webarchive|url=https://web.archive.org/web/20121208184918/http://www.spinemd.com/publications/articles/reliability-and-accuracy-of-fine-cut-computed-tomography-scans-to-determine-the-status-of-anterior-interbody-usions-with-metallic-cages |date=2012-12-08 }}</ref>