The history of science brims with episodes of nasty bickering between rival scientists over credit for major discoveries."" So remarks New York Times reporter Kleinfield in this fast-paced narrative of the development of nuclear magnetic resonance (NMR) imagery. The contenders were Paul Lauterbur, a chemist, and Raymond Damadian, a physician/biophysicist/mathematician. NMR as a phenomenon was discovered in the 1940's; it has to do with the fact that the protons in atomic nuclei of most atoms behave like tiny bar magnets. Normally, they are randomly oriented, but they can be forced to line up in two different arrays when a strong external magnetic field is imposed. If a radio signal is then beamed at the appropriate (resonating) frequency, the protons in one array absorb the signal and flip over to the other array. When the signal is turned off, the nuclear particles return to their resting state. Physicists used this property effectively to analyze complex molecules. The idea of using NMR to make 3-D images of living tissues occurred to both Lauterbur and Damadian in the 1970's; both were aware that living tissue is about 80% water and water's hydrogen atoms give off the most powerful NMR signals. Moreover, both were convinced that NMR images would show significant differences between normal and cancerous tissues. But their personalities, professional standings, and approaches were miles apart. Damadian was brash and braggadocio--just the sort of new boy on the block to raise the hackles of senior scientists and conservative grant administrators. Sheer backbreaking work and an ability to enlist the devotion of an odd mâ€šlange of lab talents finally won the day for Damadian: his machine called ""Indomitable"" produced the first whole body images of living human tissue. Kleinfield has a fine reporter's eye and ear for detail, describing the chaos of Damadian's lab during the assembly of the Indomitable, and telling such hapless tales as Damadian's trekking off to Plains, GA, to enlist the aid of any and all Carters to fund his dream. Details of machine assembly will likely appeal to Popular Science, types, for this sort of bio-technology is truly a marriage of electronics and mechanics. To his credit, too, he has interviewed and provides sympathetic treatments of Lauterbur and some principal English contenders, but it is clear that only one emerges as ""the Indomitable.