INTRODUCTION & HISTORY OF COMPUTED TOMOGRAPHY (CT)

By MAAJID MOHI UD DIN MALIK Radiology Hub -January 09, 2023

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INTRODUCTION & HISTORY OF COMPUTED TOMOGRAPHY (CT)

INTRODUCTION

Medical imaging technology has experienced tremendous changes in the last five decades in both technology and clinical areas. New innovations and developments have become routine or mainstream in the radiology department. The goal of these new developments is to optimize and advance the technical parameters of the existing examinations and improve the image quality needed for the diagnosis, more importantly, provide improved patient care and safety during these examinations. Among these new technologies one such development that is an uprising or revolutionary tool of medicine, particularly in the field of medical imaging, is computed tomography (CT), which become one of the important tools for the evaluation and diagnosis of different abnormalities and pathologies by taking cross sections images of an object in a single axis from multiple directions.

The word tomography is derived from the Ancient Greek word tomos (slice, section) and graphein (to write or to describe). The word tomography is not new

in the field of imaging. It can be tracked down back to the 1920s when the method to image a specific section of radiography was discovered, at that time this technique was known as “body section radiography”. In 1935 Grossman refined the technique and labelled it as “tomography”.

COMMON NAMES OF CT

Ø Computerized axial transverse scanning.

Ø Computerized axial tomography.

Ø X-ray computed tomography.

Ø Computed/computerized tomography

Now computed tomography is commonly used and accepted worldwide.

HISTORY OF COMPUTED TOMOGRAPHY

The history of computed tomography starts back in 1917 when an Austrian mathematician Johann Karl August Radon developed a mathematical theory of the Radon transforms.

Ø In 1917-Radon developed the basic mathematics equation.

Ø In 1920-the method to image a “specific section of the radiography” was developed.

Ø In 1935- Grossman refined the technique and labelled it as “tomography”.

Ø In 1937- Watson developed another tomography technique and this is known as “transverse axial tomography”.

Ø In 1940- Frank and Takahashi published the basic principle of axial computed tomography (CT).

Ø In 1956- Alan M Cormach developed the theory of imaging reconstruction.

Ø In 1971- Godfrey Newbold Hounsfield developed the clinically useful computed tomography scanner.

Ø In 1974- the first clinical brain scan was done. The first CT took several hours to acquire the raw data for a single slice and overnight for reconstruction.

Ø In 1979- A dynamic spatial reconstructor (D S R) was installed in the bio-dynamic unit at the mayo-clinic.

Ø In 1980- A high-speed CT scanner was introduced that used electron beam technology by Dr Doubles (University of California).

Ø Electron beam technology was used to image the cardiovascular system to overcome motion artefact problems. This scanner is known as EBCT.

Ø In 1992- A dual-slice spiral/helical CT scanner was introduced.

Ø In 1998- A MSCT was introduced at the radiological society of North America (RSNA) in Chicago.

Ø Multi-slice computed tomography (MSCT) is based on the use of multi-detector technology to scan more slices per rotation.

Ø In 2000- 8-16 and 32-64 slice CT scan was introduced.

Ø In 2004- a 64-slice CT scanner was introduced.

Ø In 2006- A dual-source CT scanner was introduced - 2 x-ray tubes coupled to 2 detector arrays.

Ø In 2006-2007- 256 and 320 slices were introduced and used for clinical practice.

In the year 1979, both Allan M Cormack and Godfrey Newbold Hounsfield were given Nobel Prize in Physiology or Medicine "for the development of computer-assisted tomography."