Editing CT scan (section)

=== Cardiac ===
A CT scan of the heart is performed to gain knowledge about cardiac or coronary anatomy.<ref>{{Cite web |title=Cardiac CT Scan – NHLBI, NIH |url=https://www.nhlbi.nih.gov/health/health-topics/topics/ct |url-status=live |archive-url=https://web.archive.org/web/20171201032800/https://www.nhlbi.nih.gov/health/health-topics/topics/ct |archive-date=2017-12-01 |access-date=2017-11-22 |website=www.nhlbi.nih.gov}}</ref> Traditionally, cardiac CT scans are used to detect, diagnose, or follow up [[coronary artery disease]].<ref name="Wichmann">{{Cite web |last=Wichmann |first=Julian L. |title=Cardiac CT {{!}} Radiology Reference Article {{!}} Radiopaedia.org |url=https://radiopaedia.org/articles/cardiac-ct-1 |url-status=dead |archive-url=https://web.archive.org/web/20171201040626/https://radiopaedia.org/articles/cardiac-ct-1 |archive-date=2017-12-01 |access-date=2017-11-22 |website=radiopaedia.org}}</ref> More recently CT has played a key role in the fast-evolving field of [[Interventional cardiology|transcatheter structural heart interventions]], more specifically in the transcatheter repair and replacement of heart valves.<ref>{{Cite journal |last1=Marwan |first1=Mohamed |last2=Achenbach |first2=Stephan |date=February 2016 |title=Role of Cardiac CT Before Transcatheter Aortic Valve Implantation (TAVI) |journal=Current Cardiology Reports |volume=18 |issue=2 |pages=21 |doi=10.1007/s11886-015-0696-3 |issn=1534-3170 |pmid=26820560 |s2cid=41535442}}</ref><ref>{{Cite journal |last1=Moss |first1=Alastair J. |last2=Dweck |first2=Marc R. |last3=Dreisbach |first3=John G. |last4=Williams |first4=Michelle C. |last5=Mak |first5=Sze Mun |last6=Cartlidge |first6=Timothy |last7=Nicol |first7=Edward D. |last8=Morgan-Hughes |first8=Gareth J. |date=2016-11-01 |title=Complementary role of cardiac CT in the assessment of aortic valve replacement dysfunction |journal=Open Heart |volume=3 |issue=2 |pages=e000494 |doi=10.1136/openhrt-2016-000494 |issn=2053-3624 |pmc=5093391 |pmid=27843568}}</ref><ref>{{Cite journal |last1=Thériault-Lauzier |first1=Pascal |last2=Spaziano |first2=Marco |last3=Vaquerizo |first3=Beatriz |last4=Buithieu |first4=Jean |last5=Martucci |first5=Giuseppe |last6=Piazza |first6=Nicolo |date=September 2015 |title=Computed Tomography for Structural Heart Disease and Interventions |journal=Interventional Cardiology Review |volume=10 |issue=3 |pages=149–154 |doi=10.15420/ICR.2015.10.03.149 |issn=1756-1477 |pmc=5808729 |pmid=29588693}}</ref>

The main forms of cardiac CT scanning are:
*[[Coronary CT angiography]] (CCTA): the use of CT to assess the [[coronary artery|coronary arteries]] of the [[heart]]. The subject receives an [[intravenous injection]] of [[radiocontrast]], and then the heart is scanned using a high-speed CT scanner, allowing radiologists to assess the extent of occlusion in the coronary arteries, usually to diagnose coronary artery disease.<ref>{{Cite book |last=Passariello |first=Roberto |url=https://books.google.com/books?id=eR5USB6sRU4C&q=ct+angiography |title=Multidetector-Row CT Angiography |date=2006-03-30 |publisher=Springer Science & Business Media |isbn=978-3-540-26984-7}}</ref><ref>{{Cite web |last1=Radiological Society of North America |last2=American College of Radiology |title=Coronary Computed Tomography Angiography (CCTA) |url=https://www.radiologyinfo.org/en/info.cfm?pg=angiocoroct |access-date=2021-03-19 |website=www.radiologyinfo.org}}</ref>
*[[Coronary CT calcium scan]]: also used for the assessment of severity of coronary artery disease. Specifically, it looks for calcium deposits in the coronary arteries that can narrow arteries and increase the risk of a heart attack.<ref name="mayo">{{Cite web |title=Heart scan (coronary calcium scan) |url=http://www.mayoclinic.org/tests-procedures/heart-scan/basics/definition/prc-20015000 |url-status=live |archive-url=https://web.archive.org/web/20150905084216/http://www.mayoclinic.org/tests-procedures/heart-scan/basics/definition/prc-20015000 |archive-date=5 September 2015 |access-date=9 August 2015 |publisher=Mayo Clinic}}</ref> A typical coronary CT calcium scan is done without the use of radiocontrast, but it can possibly be done from contrast-enhanced images as well.<ref name="van der BijlJoemai2010">{{Cite journal |last1=van der Bijl |first1=Noortje |last2=Joemai |first2=Raoul M.S. |last3=Geleijns |first3=Jacob |last4=Bax |first4=Jeroen J. |last5=Schuijf |first5=Joanne D. |last6=de Roos |first6=Albert |last7=Kroft |first7=Lucia J.M. |year=2010 |title=Assessment of Agatston Coronary Artery Calcium Score Using Contrast-Enhanced CT Coronary Angiography |journal=American Journal of Roentgenology |volume=195 |issue=6 |pages=1299–1305 |doi=10.2214/AJR.09.3734 |issn=0361-803X |pmid=21098187}}</ref>

To better visualize the anatomy, post-processing of the images is common.<ref name="Wichmann" /> Most common are multiplanar reconstructions (MPR) and [[volume rendering]]. For more complex anatomies and procedures, such as heart valve interventions, a true [[3D reconstruction]] or a 3D print is created based on these CT images to gain a deeper understanding.<ref>{{Cite journal |last1=Vukicevic |first1=Marija |last2=Mosadegh |first2=Bobak |last3=Min |first3=James K. |last4=Little |first4=Stephen H. |date=February 2017 |title=Cardiac 3D Printing and its Future Directions |journal=JACC: Cardiovascular Imaging |volume=10 |issue=2 |pages=171–184 |doi=10.1016/j.jcmg.2016.12.001 |issn=1876-7591 |pmc=5664227 |pmid=28183437}}</ref><ref>{{Cite journal |last1=Wang |first1=D. D. |last2=Eng |first2=M. |last3=Greenbaum |first3=A. |last4=Myers |first4=E. |last5=Forbes |first5=M. |last6=Pantelic |first6=M. |last7=Song |first7=T. |last8=Nelson |first8=C. |last9=Divine |first9=G. |last10=Taylor |first10=A. |last11=Wyman |first11=J. |last12=Guerrero |first12=M. |last13=Lederman |first13=R. J. |last14=Paone |first14=G. |last15=O'Neill |first15=W. |year=2016 |title=Innovative Mitral Valve Treatment with 3D Visualization at Henry Ford |url=http://www.materialise.com/en/blog/innovative-mitral-valve-treatment-3d-visualization-at-henry-ford |url-status=dead |journal=JACC: Cardiovascular Imaging |volume=9 |issue=11 |pages=1349–1352 |doi=10.1016/j.jcmg.2016.01.017 |pmc=5106323 |pmid=27209112 |archive-url=https://web.archive.org/web/20171201043336/http://www.materialise.com/en/blog/innovative-mitral-valve-treatment-3d-visualization-at-henry-ford |archive-date=2017-12-01 |access-date=2017-11-22}}</ref><ref>{{Cite journal |last1=Wang |first1=Dee Dee |last2=Eng |first2=Marvin |last3=Greenbaum |first3=Adam |last4=Myers |first4=Eric |last5=Forbes |first5=Michael |last6=Pantelic |first6=Milan |last7=Song |first7=Thomas |last8=Nelson |first8=Christina |last9=Divine |first9=George |date=November 2016 |title=Predicting LVOT Obstruction After TMVR |journal=JACC: Cardiovascular Imaging |volume=9 |issue=11 |pages=1349–1352 |doi=10.1016/j.jcmg.2016.01.017 |issn=1876-7591 |pmc=5106323 |pmid=27209112}}</ref><ref>{{Cite journal |last1=Jacobs |first1=Stephan |last2=Grunert |first2=Ronny |last3=Mohr |first3=Friedrich W. |last4=Falk |first4=Volkmar |date=February 2008 |title=3D-Imaging of cardiac structures using 3D heart models for planning in heart surgery: a preliminary study |journal=Interactive Cardiovascular and Thoracic Surgery |volume=7 |issue=1 |pages=6–9 |doi=10.1510/icvts.2007.156588 |issn=1569-9285 |pmid=17925319 |doi-access=free}}</ref>