This book is a supplement to Volume V/I in the present series, Diag- nostie Radiology, published in 1962. Despite the relatively long period of time whieh has elapsed sinee its publieation, that eomprehensive vol- urne is still essentially valid, even though further developments have of course oeeurred in eertain fields. In reeent years the developments in nuclear medieine and ultrasonie teehniques have led to a number of new methods of medieal investigation, whieh, in different ways, eomplement diagnostie radiology. Funetional disorders of the urinary traet ean often be detected by means of radioiso- topes. Sinee morphologie ehanges are almost always preeeeded by fune- tional disturbanees, radionuclide teehniques in many instanees produee an earlier diagnosis than radiography. Disturbances of renal blood flow, slight ureterie obstruetion, and ureterie reflux are examples of pathologie states whieh ean be deteeted early by the y scintillation eamera. Bone seans, Le., imaging of the skeletal system using a radionuclide, are used extensively to diagnose bone metastases now that it has been demonstrated that such metastatie growths are identified both earlier and with greater aeeuraey by scintigraphy than by radiographie teeh- niques.