INNOVATION AND CHANGE
Making a Change : How the Development of the Computed Axial Tomography ( CAT ) Scan Revolutionized Diagnostic Radiology
I
think of the 1970s as a decade of momentous change in diagnostic radiology . During our residency at the University of Louisville ( 1974-1977 ) my fellow residents and I witnessed a series of technical advances that allowed us to move from the archaic world of dangerous and decidedly patient unfriendly diagnostic methods into the future . I refer specifically to the development of the first commercially viable CAT head scanner . This was produced at the Electric & Musical Industries ( EMI ) Central Research Laboratories , Hayes , England , the brainchild of Sir Godfrey Hounsfield . 1 The first clinical installation was at the Atkinson Morley Hospital in Wimbledon in 1971 . In October of that year , the first patient was scanned . The clinical diagnosis of left frontal lobe tumor was confirmed , and the patient underwent successful surgery . 2 The first U . S . installation was at the Mayo Clinic in 1973 . Their original
by ELIZABETH AMIN , MD machine remains on display in the imaging department . 1
We received our very own EMI scanner in the Radiology Department at the old Louisville General Hospital in 1976 . Our EMI 1010 was the second generation of EMI head scanners . One significant difference between first and second generation was the structured component that surrounded the patient ’ s head in the scanner . In the first generation , this consisted of a rubber sock into which the patient ’ s head was positioned . The sock completed the sixth side of a plastic box which was filled with water . The water provided a mechanism for X-ray beam attenuation and also a reference for CAT number accuracy . In the second-generation scanner , the water box was replaced with a carbon attenuator . Another significant difference was the increase in number of X-ray detectors to eight , meaning that the time to scan two contiguous 13 mm slices of the brain was reduced from five minutes to one .
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