Today, engineering achievements have reached their zenith in the special procedure room of the department of radiology; it has become mandatory for the radiologist to be knowledgeable in the basic sciences. In the recent past, a radiologist could be of service using a pattern-dependent approach, perhaps relying on dimly remembered dynamic principles only when fluoroscoping the heart or gastrointestinal tract. But even here the major emphasis was on structure, not function. This is no longer possible. Now, he must be well grounded in fundamental disciplines. In special and conventional roentgen studies, motion is the key word. The most impenetrable viscera are fair game for catheter, scintillation counter, television screen, or movie camera. The radiologist who fails to think in dynamic terms misses many opportunities to retrieve information.
Lasser has attempted to compile and correlate physiologic principles with roentgen diagnosis and to confine this information within the framework of a