Other Imaging Careers
Magnetic Resonance Imaging (MRI) Nuclear Medicine Sonography (Ultrasound) Cardiovascular Interventional Radiography Radiation Therapy
Computed Tomography:
Commonly known as "CAT Scanners" or "CT," computed tomography units use an x-ray tube that revolves around the patient's body while hundreds of radiation measurements are taken by an array of detectors on the opposite side. All of these measured values are sent to a large computer. By comparing the measurements taken from different angles, the computer is able to "reconstruct" a usable image. It is as though hundreds of partial x-rays were combined to form a complete image in another plane, a plane that takes a "slice" out of the patient. This marvelous technology allows us to effectively dissect a patient without ever touching them!
Since CT uses x-radiation, only certified radiographers may train to become CT technologists. After completing a regular radiography program, additional study must be undertaken. An advanced certification exam published by the A.R.R.T. may be taken.
MRI units utilize huge electromagnets and radio waves to create "slice" images, effectively dissecting the patient just like CT images do. However, MRI uses no harmful ionizing radiation, and MRI images demonstrate certain anatomical structures and diseases better than CT images.
When the patient is placed into the MRI gantry, hydrogen protons in the body are magnetized and "point" toward the north pole of the MRI magnet. But they also wobble like a spinning top. When radio waves that are "tuned" to the rate of that wobbling motion are aimed at the patient, they knock over the protons. The radio burst is then shut off, allowing the protons to "stand back up" and point "north" again. They actually spiral back up in a wobbling motion, which causes secondary radio waves. Amazingly, the body has been induced to emit its own radio waves!
Hundreds of radio measurements, encoded as to their location of origin, are taken by an array of detectors. As with CT, all of these measured values are sent to a large computer and a composite image is "reconstructed."
To specialize in MRI, after completing a regular radiography program, additional study must be undertaken. An advanced certification exam published by the A.R.R.T. may be taken.
Cardiovascular Interventional Radiography:
CIV is a challenging mixture of surgical techniques and radiography. By various catheterization methods, iodine compounds that show up on x-rays can be injected directly into the chambers of the heart, the aorta, or the vessels of various organs such as the brain. Advanced technology allows rapid filming sequences or motion pictures to be taken of these circulatory vessels for diagnosis. And, with special catheters and other equipment, certain treatments can now be administered while the patient is on the x-ray table.
Graduates of a regular radiography program can complete additiona study and can then become certified by taking an exam published by the A.R.R.T.
Certain radioactive chemicals can be safely injected into the human body, which produce enough radiation to create a useful image, yet actually expose the patient to less radiation than a typical x-ray series. These substances are chemically "tagged" to elements which tend to concentrate in specific organs: Iron goes to the liver and potassium to bone, while iodine tends to concentrate in the thyroid gland. Each radiation wave emitted from the organ under study is picked up by detectors and displayed as a dot on a TV screen. The composite of dots forms an image, in which an area of unusual concentration or a lack of signal can indicate a diseased portion of the organ.
Students with some college background can go into two-year nuclear medicine schools, or graduates of a regular radiography program can complete a one-year program. They can then become certified by taking an exam published by the A.R.R.T. or by the NMTCB.
Sonography units emit sound waves that have a frequency much higher than the human ear can hear. These sound waves will reflect off of different anatomical structures just as a shout will echo from a canyon wall. By measuring how long it takes for the sound waves to reflect back to the machine's transducer, the organs can be located. The strength of the returning wave gives an indication of the type of tissue that reflected it. A computer can create a useful image from these measurements.
Students with some college background can go into a sonography program of 18 - 24 months duration. They can then become certified by taking an exam published by the A.R.R.T. or by the RDMS. Midland College offers a 18-month program in sonography. Students certified in a health care field are preferred.
Radiation therapy technologists apply large, carefully calculated doses of ionizing radiation to specific locations in the body in order to destroy cancer cells. Over a period of several treatments, many kinds of tumors can be successfully treated in this manner.
Students with some college background can go into two-year radiation therapy schools, or graduates of a regular radiography program can complete a one-year program. They can then become certified by taking an exam published by the A.R.R.T.