Roentgen examination of the liver.

Abstract

The long history of research into methods for the roentgen demonstration of the liver and its internal structures is a record of disappointments. Considering the five tubular structures and the two sets of cells, hepatic and reticuloendothelial, by which a contrast substance could be introduced into the liver, it is indeed surprising that more success has not attended such efforts. No doubt the great bulk of the liver and the lack of access to it from without have been in large part responsible for the unsatisfactory results. Attempts to find a harmless substance specifically excreted or secreted by the liver in sufficient quantities to make the internal anatomy of the organ visible in the roentgenogram have uniformly failed. That the size and shape of the liver can be demonstrated either by direct radiographic study or by pneumoperitoneum is evident, but such findings add little to our diagnostic ability. When cholecystography was first introduced, it was hoped that sufficient amounts of the contrast substance would fill the bile canaliculi, before passage into the bile ducts, to produce a roentgenogram of the liver parenchyma. Although the gallbladder and, to a lesser degree, the external bile ducts, were visualized in this way, the intrahepatic ducts and the liver cells could not be seen. Then followed the demonstration that the biliary duct system could be made visible by injection during a laparotomy or afterward, through a surgically created external fistula. Various means were proposed to permit injection of the biliary ducts or gallbladder through the intact abdominal wall, either blindly or with the aid of the peritoneoscope. The recent development of intravenous cholangiography has solved, to a partial degree at least, the problem of roentgenography of the biliary duct system. Altogether, x-ray study of the bile ducts can now be reasonably well accomplished. The introduction into the blood stream of a stable colloidal substance, Thorotrast, which has a high opacity to roentgen rays and is absorbed by the reticuloendothelial cells of the liver, resulted in a brilliant demonstration of the size, shape, and position of the liver and of its internal structures (16, 17). By this means, tumors of the liver, cirrhosis, and various other diseases could be effectively portrayed. Unfortunately, this substance is slightly radioactive and, what is even more important, it remains almost permanently within the liver after its introduction. There is some evidence that it may be slightly carcinogenic. As a practical method for the roentgen study of this organ, it has therefore fallen into disuse. Various other colloidal substances, with iodine as the opaque medium, were then prepared (2, 8). While some proved effective in producing contrast, none has been free from serious hazard and they are therefore rarely used. An excellent summary of such studies was presented by Gershon-Cohen and McClendon (12).