A review of The Encyclopaedia of Medical Imaging requires superlatives. Truly a magnum opus, it is available either as a CD-ROM or as eight separate volumes, all of which have been created in the past 4 years. This herculean undertaking was directed by editor-in-chief Holger Pettersson with the aid of an assistant editor and associate editors of world renown in radiology, including representatives from both North America and western Europe.