The most common x-ray is the chest film, which is used for a variety of purposes. The posteranterior and lateral chest x-rays are simple methods of detecting lung cancers or lesions metastatic to the lung from other primary cancer sites. The x-ray can show the tumor size, location, obstruction, pleural effusion, or invasion of adjacent structures such as the chest wall or [glossary term:] mediastinum.
Mammography is an x-ray technique used to diagnose abnormalities in the breast. Usually, two views are taken of each breast, and the radiographs are examined for lesions or micro calcifications. The mammogram is useful in localizing suspicious nonpalpable lesions. The area of concern is visualized while the breast is in the mammography unit. The radiologist injects dye or inserts a special hookwire needle into the suspicious area. The surgeon is then able to excise the abnormal area.
The most common x-ray used for the diagnosis of colon cancer is the barium enema. The large colon is filled with a barium solution and multiple x-ray films are taken. Polyps, as well as constricted and obstructed areas, can be seen. The upper GI series is useful in diagnosing lesions of the pharynx, esophagus, stomach, and small intestine.
One common radiological exam used in the study of the urinary tract is the KUB, a frontal film of the abdomen used to examine the kidneys, ureters, and bladder. There are several other urinary tract x-ray exams that use a contrast medium (a radiopaque substance to delineate and define the contour of the structures). The intravenous [glossary term:] pyelogram (IVP) follows the injection of the contrast media into a vein and displays the path of the media through the kidneys, ureters, and bladder. A retrograde urogram is carried out by inserting a cystoscope into the ureteral meatus, inserting a catheter through the cystoscope, and adding a contrast solution to study the renal pelvis and ureters. The location and size of the tumors of the urinary tract can often be defined through these x-rays studies.
An angiogram is an x-ray study of the vascular system that is used to diagnose some cancers. A cerebral angiogram helps define the blood supply to brain lesions. [glossary term:] Lymphangiograms are useful in the study of vessels of the lymphatic system. They were widely used as a staging workshop for lymphomas before the widespread availability of CT and MRI scanning.