Development of CT

Development of the Computed Tomography (CT) Scanner

Sue Edyvean

St. George’s Hospital, London

Development of CT

Computed Tomography

• Images ‘slices’ through the patient– ‘Graphia’ – to write, to draw

– ‘Tomos’ – cut, incision, section

– ‘Computed’ – determined by mathematical methods

Development of CT

• CT scanner developed at EMI Medical by Godfrey Hounsfield

Development of the CT Scanner

Development of CT

• Prototype installed at Atkinson Morley’s Hospital, Wimbledon, London

Development of the CT Scanner

Development of CT

• Support of Dr James Ambrose, Neuro-radiologist AMH

Development of the CT Scanner

Godfrey Hounsfield, James Ambrose

Development of CT

• 1st clinical scan 1st October 1971

Development of the CT Scanner

Development of CT

• Godfrey Hounsfield – EMI, inventor of clinical CT 1971 (design)– 1979 Nobel prize (jointly with Cormack)

• Dr. James Ambrose – Neuroradiologist AMH (clinical)– Standing ovation at RSNA 1972

• Dr. BJ Perry – Head of Medical Physics SGH/AMH (radiation)– Dosimetry and image quality, measurements and methods

British Journal of Radiology 1973 – three linked papers

Godfrey Hounsfield James Ambrose John Perry

(GH died Aug 12th 2004, JA died March 12th 2006)

Development of CT

CT scanner development 1971

• 2 x (8 – 10 mm), first dual slice scanner, • 80 x 80 matrix• 4 min per rotation

Development of CT

• Data tapes sent away overnight for image reconstruction• Paper (CT numbers) or polaroid (Scan numbers 200 and 215,

images A and B refer to the two slices imaged simultaneously)

Early Clinical Images - AMH Scanner

Development of CT

CT scanner development 1971

• Scanner is now in the science museum

Development of CT

Godfrey Hounsfield – Nobel Speech 1979

Fig. 14 shows a picture from the experiment. The heart chambers can be discerned by a little intravenous injected contrast media.

A further promising field may be the detection of the coronary arteries. …. It may be possible to detect these under special conditions of scanning.

Development of CT

2010 Scanning the heart has become a reality

SOMATOM DefinitionFlash

Temp res. 75 msColl. 128 x 0.6 mmSpatial res. 0.33 mm350 ms for 149 mmRotation 0.28 s100 kV, 290 mAs/ rotation

0.90 mSv

Development of CT

Development of the CT Scanner