More information on the Open Book is available. Copyright 1989, the National Academy Press. Keywords, machine extracted. Top 50 words repeated twice, next 100 once, plus phrases. With this data, the CAT scan computer generates an image showing the structure in that cross section of her head.
CAT scans are particularly good for showing the fine detail of bone structure.
The machine is called a CAT scan, for computerized axial tomography scanner. Indeed, many doctors believe that more progress has been made in medical diagnos- tics since the CAT scan was introduced than in all previous medical history. CAT has so far had the widest impact of the new imaging technologies. It has saved untold numbers of lives by quickly finding tumors, infections, bleeding, and blood clots that would have been found too late or missed altogether by regular x-rays or other diagnostic techniques. A normal series of 30 scans is performed in about 20 minutes and usually without injections.