Computed Axial Computed Axial Tomography Tomography

MachinesMachinesBy: Jay PatelBy: Jay Patel

BME 181BME 181Professor: Ming LiuProfessor: Ming Liu

What is a CAT Scan?What is a CAT Scan?

It is a non-invasive medical imaging procedure that It is a non-invasive medical imaging procedure that combines the use of X-rays and computer combines the use of X-rays and computer processing to generate tomographic (‘slices’) of the processing to generate tomographic (‘slices’) of the area scannedarea scanned

Four classifications of the types of scans: Four classifications of the types of scans: -Abdominal-Abdominal-Bone-Bone-Head-Head-Vascular-Vascular

Present-Day CAT Scan Present-Day CAT Scan MachineMachine

BackgroundBackground

Was formally introduced in 1972 by a British Was formally introduced in 1972 by a British engineer Sir Godfrey Hounsfieldengineer Sir Godfrey Hounsfield

The first scan was done in 1971, of the brainThe first scan was done in 1971, of the brain

Physicist Allan Cormack also invented a similar Physicist Allan Cormack also invented a similar machine in the United Statesmachine in the United States

Both Cormack and Hounsfield were awarded the Both Cormack and Hounsfield were awarded the Nobel Prize in 1979 Nobel Prize in 1979

First clinical scanners were installed in 1974First clinical scanners were installed in 1974

Was a revolutionary invention in terms of medical Was a revolutionary invention in terms of medical imagingimaging

Notable AdvancementsNotable Advancements

First invented scanners were only dedicated to head First invented scanners were only dedicated to head imagingimaging

Full body CAT scan machines were not widely Full body CAT scan machines were not widely available until 1980available until 1980

Over the years, scan speeds have drastically Over the years, scan speeds have drastically increased going from a few hours to just minutesincreased going from a few hours to just minutes

The resolution of the scanned images are 16x betterThe resolution of the scanned images are 16x better

Improved designs of the machines allow all the Improved designs of the machines allow all the ‘slices’ to be put together so the image is ‘slices’ to be put together so the image is continuouscontinuous

Procedure for ScanProcedure for Scan

Depending on the type of scan, you may not be Depending on the type of scan, you may not be allowed to eat/drink a few hours prior to scanallowed to eat/drink a few hours prior to scan

Wear comfortable clothing or a gown will be Wear comfortable clothing or a gown will be providedprovided

All metal and electronic possessions that can be All metal and electronic possessions that can be removed must be removedremoved must be removed

Intravenous contrast (if necessary) is injected into Intravenous contrast (if necessary) is injected into patientpatient

Patient is then asked to lay on the machine Patient is then asked to lay on the machine platform, and alignedplatform, and aligned

How it FunctionsHow it Functions

Image from ScanImage from Scan

Limitations/Limitations/ConsiderationsConsiderations

Cost: Ranges from $250-5000+Cost: Ranges from $250-5000+

Restriction on number of exams in a given period of Restriction on number of exams in a given period of timetime

Women who are pregnant, generally are Women who are pregnant, generally are discouraged from having a CAT scan performeddiscouraged from having a CAT scan performed

Risk of getting cancerRisk of getting cancer

Intravenous or oral contrast can be uncomfortableIntravenous or oral contrast can be uncomfortable

Future: Decrease the time needed for scan/Decrease Future: Decrease the time needed for scan/Decrease the amount of radiation required for scanthe amount of radiation required for scan

ReferencesReferences

http://melissaheart.blogspot.com/2011/04/cat-scan-dangers.html - 4/18/13 - 4/18/13

https://blogs.lsc.edu/dalagest/files/2009/02/ctscan.jpg - 4/18/13- 4/18/13

http://www.dydent.com/ctscanhistory.htm - 4/18/13 - 4/18/13

http://www.imaginis.com/ct-scan/brief-history-of-ct ct - 4/19/13- 4/19/13

http://en.wikipedia.org/wiki/X-http://en.wikipedia.org/wiki/X-ray_computed_tomographyray_computed_tomography- 4/19/13- 4/19/13

http://www.radiologyinfo.org/en/info.cfm?pg=bodycthttp://www.radiologyinfo.org/en/info.cfm?pg=bodyct- 4/19/13- 4/19/13