SCIENTIFIC IMPORTANCE OF X-RAYS—GARLAND 187 
reasons why a consultant roentgenologist may require stereoscopic 
or other additional projections even though you present yourself 
with a perfectly good film made elsewhere only a few days before. A 
small wart on the back may be projected on a film in a manner 
identical with that of a kidney stone or gall stone. Visual exam- 
ination of the undressed patient or stereoscopic projections should 
prevent an error being made. In general, it is advisable for persons 
to be undressed when having X-rays taken, since objects such as ear- 
rings have been mistaken for misplaced toothroot fragments, buttons 
for gallstones, and the edge of folded clothing for fractures. Faulty 
darkroom technique sometimes results in undeveloped or fogged areas 
of films which can suggest (in chest films) pneumonia or (in films 
of the limbs) diseased bone, even to the initiated. 
The use of X-ray methods in medical diagnosis may be outlined 
in relation to the various systems of the body. 
Alimentary system.— X-ray examination of the alimentary system 
permits the early diagnosis of a vast number of common disease con- 
ditions, ranging from adhesions to volvulus. Both fluoroscopic and 
film examinations are usually essential. The fluoroscopic examination 
discloses facts regarding the mobility and function of organs which 
cannot be obtained from films alone; the films in turn reveal detail 
of structure which cannot be appreciated on the fluoroscopic screen. 
The value of either method depends on the skill, patience, and ex- 
perience of the examiner. When it is a question of a condition such 
as early stomach cancer, the examination may have to be repeated 
two or three times before a reliable opinion can be rendered. For the 
upper part of the system (the gullet, stomach, and small intestine) 
it is necessary for the patient to come fasting. He is given a drink 
of barium sulfate suspended in water and the appearance of these 
portions of the tract is studied under the fluoroscope. Patients often 
complain at the chalky taste of the bariumized water. The reason 
that flavoring agents are not used is that in some persons they stimu- 
late large amounts of gastric secretion which dilutes the test meal 
undesirably. In the early days of roentgenology the barium or bis- 
muth used to be given in flavored preparations. However, if these 
contained much milk or cream, stomach emptying would be (physio- 
logically) delayed. If they contained much sugar, stomach emptying 
would be hastened. These conditions often resulted in erroneous con- 
clusions as to the presence of gastric stasis. In the average case 4 
ounces of barium sulfate (by weight) are given in about 8 ounces of 
water. This eventually mixes with the other contents of the intestinal 
tract and does not require laxation for its natural ejection. 
The lower portion of the alimentary system normally is examined 
by barium enema. Sixteen ounces of barium sulfate are suspended 
725362—47——14 
