Cancer Articles (Dr. S.N White)

What is a CT scan?  "CT" stands for " computerized tomography ." A newer way of looking inside the human body, it uses pencil like x-ray beams to scan the section of the body being studied. It combines the speed of a computer with the sensitivity of the x-ray detectors. Sometimes you will hear the terms tomographic scanner, ACTA scanner ("ACTA" stands for "automatic computerized transverse axial scanner"), or CAT ("computerized axial tomography"). They all mean the same thing. How does the CT scanner work?  The CT takes a three dimensional look inside the body. The scanner has an arm which directs the beam through the body as it rotates around you. The x-rays pass through the body and are detected by an electronic device. About 160 scans are made in one position; then the detectors are rotated and the 160 scans are repeated. Link What does the computer do?  As the beam moves around the body in the same plane, a minicomp...

What is a fluoroscope?  This is a kind of x-ray in which a special machine ( the fluoroscope ) takes a continuous x-ray so that the doctor can see the movement of internal organs. A fluorescent screen, coated with a special substance, is mounted in front of an x-ray tube. The x-ray shadow is cast on the screen. The fluoroscopic image can be amplified and displayed on a television screen. Fluoroscopy can show the expansion of the lung or a barium liquid passing through a patient's esophagus to his stomach. Fluoroscopic techniques sometimes provide important information which cannot be obtained in any other way. How much radiation exposure will I get from a fluoroscope? Fluoroscopes take longer to perform and often expose you to more radiation than do the conventional x-ray exams recorded on film. There are new machines which give better images with less exposure, particularly those which amplify the light from the fluoroscopic screen and then provide a brighter image on a TV...

Lymphangiography is important to cancer diagnosis because one of the ways that cancer spreads is through the lymph nodes. Lymphangiography can be useful in the diagnosis and staging of persons with Hodgkin's disease and lymphomas and sometimes for other cancers. It is a procedure which is done in an outpatient setting or in a hospital. A blue dye is injected into the small lymph vessel after a cut is made in the big toe. The lymph system in the abdomen can then be looked at by means of x-rays. Since the lymph glands are very small, it usually takes 2 to 3 hours for the dye to reach the lymph nodes. Lymphangiography is used to localize and determine the extent of the tumors. The surgeon can use it as a guide to finding specific lymph nodes and determining the size of the tumor. The radiotherapist uses it to evaluate how a person is responding to therapy. Since the dye stays in the system for some 3 to 4 months, progress usually can be followed through x-rays without repeating the p...