Cannon lecture. The impact of radiology on hepatology

Because of remarkable advances in diagnostic imaging and the development of a variety of useful interventional techniques, radiology now plays a central role in the diagnosis and treatment of patients with hepatic disease. These include focal, vascular, and metabolic liver diseases, abnormalities of the biliary tract, and conditions associated with hepatic transplantation. Thus, optimal care of patients with liver disease now requires that there be close cooperation between the two specialties.     

The Reference Man in diagnostic radiology dosimetry.

Following the legislation for radiation protection in Europe, increasing interest has been given to patient dosimetry in diagnostic radiology. Dose comparisons between groups of patients have demonstrated considerable discrepancies. The equipment, as well as the procedures used, have been scrutinized in order to find the reasons for the variation and to reduce it. In this work, patient size and shape are considered in patient dose evaluations in diagnostic radiology. The size, shape and constitution of the patients are shown to relate exponentially to the energy imparted during examination of the trunk. The equivalent cylindrical diameter of the patient body is used as the independent variable. Exponential functions are created by linear regression. The ICRP Reference Man with an equivalent diameter of 22.9 cm is used as a body-size standard. A method is suggested by which coordinate transformations reduce data to a base line defined by the Reference Man. It is shown that the method reduces the range of energy imparted by between 30% and 60% for six common X-ray examinations of the trunk. Resulting data constitute a finer instrument for intercomparisons between hospitals for the same examination. Further, it is suggested that adipose tissues should not be included when detrimental effects of radiologic exposure are determined. The Reference Man, stripped of 10 kg subcutaneous adipose tissue, is used as the non-fat standard dimension corresponding to the equivalent cylindrical diameter 21.2 cm. The suggested method is used to estimate the fraction of energy imparted to vital organs only. The results show that the energy imparted is reduced by between 30% and 60% according to this model. Consequently, predicted deaths are reduced by the same amount.     

Interventional radiology: reflections and expectations. The 1985 Eugene P. Pendergrass new horizons lecture

The history and current practice of interventional radiology are reviewed. Interventional radiology is considered a subspecialty of diagnostic radiology that involves the use of a variety of percutaneous techniques to treat a spectrum of vascular and nonvascular diseases. It is physician intensive and requires a commitment to patient care analogous to that in surgery. Still considered in its infancy, interventional radiology should prosper and undergo continued growth over the next several decades.