Dagnostic imaging of the upper part of the abdomen.

The new diagnostic procedures developed during the last several years present a confusing dilemma. The state of the art of ultrasound, computed tomography and nuclear scintigraphy is progressing so rapidly that what one says today is generally out of date tomorrow. However, certain guidelines should be followed in evaluating various organ systems. Generally, ultrasound is the procedure of choice in the upper part of the abdomen in most patients who are not extremely obese or filled with intestinal gas. A sonogram is less expensive than computed tomography and, at the present time, is considered noninvasive compared with compound tomography, which produces a small, but significant, radiation exposure. The accuracy of the two modalities is quite similar. Using the slight advantage that computed tomography may have in a given organ system does not generally override other factors, such as cost and radiation dose. However, mitigating factors, such as obesity, presence or absence of intestinal gas or barium, should be taken into account when selecting patients for either procedure. In many clinical situations, neither computed tomography nor ultrasound should be used until other modalities, such as conventional radiography or scintigraphy, have first been tried. Should the problem not be resolved by these more conventional techniques, an ultrasound or computer tomographic examination may be indicated to delineate further the pathologic condition of the abdomen.