This book is a supplement to Volume V /1 in the present series, Diag-
nostic Radiology, published in 1962. Despite the relatively long period
of time which has elapsed since its publication, that comprehensive vol-
ume is still essentially valid, even though further developments have of
course occurred in certain fields. In recent years the developments in
nuclear medicine and ultrasonic techniques have led to a number of new
methods of medical investigation, which, in different ways, complement
diagnostic radiology. Functional disorders of the urinary tract can
often be detected by means of radioiso- topes. Since morphologic changes
are almost always preceeded by func- tional disturbances, radionuc1ide
techniques in many instances produce an earlier diagnosis than
radiography. Disturbances of renal blood flow, slight ureteric
obstruction, and ureteric reflux are examples of pathologic states which
can be detected early by the'}' scintillation camera. Bone scans, i.e.,
imaging of the skeletal system using a radionuc1ide, are used
extensively to diagnose bone metastases now that it has been
demonstrated that such metastatic growths are identified both earlier
and with greater accuracy by scintigraphy than by radiographic tech-
niques.