Computed Tomography and the Pediatric Patient
Computed Tomography (CT) or CAT scanning is generally prescribed as a safe medical procedural diagnosis for its efficient treatment of a clinical condition (Radiology Info, n.d.). This medical diagnosis combines x-ray apparatus with high-tech computers to generate cross-sectional pictures of the subjected body parts. These CT images of body parts like bones, tissues, blood vessels, and other internal organs aid medical doctors for a better clinical diagnosis (Radiology Info, n.d.). CT diagnosis is not only advised for adults but nowadays, is also widely used for children. Annually, the estimated CT scan patients in the United States of America reach about 62 million, including four million pediatric cases (Brenner and Hall, 2007). This trend is ascribed to the simplicity of CT examination process as compared with other medical tools.
Children or pediatric CT is generally used in the diagnosis and monitoring for the treatment of infectious disorders, pain, and other injury-related cases (Radiology Info, n.d.). Also, CT is used for the assessment of blood vessels, spinal cord, brain damages, lung tumor or bronchi inflammation, heart and other internal organs. In addition, CT scanning is done to detect appendicitis, colitis, cysts, birth defects, and pelvic bones, gall bladder and urinary tract disorders (Radiology Info, n.d.).
Computed Tomography (CT) Equipment
The CT machine has a central tunnel with a sliding table where patients lay down during the examination (Radiology Info, n.d.). When the patient is placed under the CT imaging system through the motorized examination table, the x-ray tube and detectors that are located in the gantry move around the patient. Then, a fan-shaped ray of light is produced by the x-ray source. In a simultaneously manner, x-ray radiation source in synchrony with the x-ray detectors, moves at each opposite sides around the patient (Brenner and Hall, 2007). For head scans, axial CT is employed wherein the motorized table after moving at the succeeding slice remains stationary. Conversely, helical CT is used for body scans wherein the motorized table simultaneously moves with x-ray source and x-ray detectors creating a spiral scan (Brenner and Hall, 2007).
The sophisticated computers which process images of the examined parts are located in a separate room. The bodily images are processed through computer software to create two-dimensional or cross-sectional images of the subjected parts (Radiology Info, n.d.). As similar with traditional x-rays, radiation is absorbed by the different body parts of the patient and white and gray appearances of the bones and tissues are observed respectively on a photographic film. Then, the radiologist will analyze and interpret the produced images. On the contrary, high level of radiation in CT improves picture quality, while in conventional radiography the results created are dark images (Frush, Donnelly, and Rosen, 2003).
CT technology made clinical diagnosis for children easy, safe, and accurate at the shortest possible time. Unlike traditional x-rays, CT scanning provides a better view of the image details of tissues, bones, and organs (Radiology Info, n.d.). Nonetheless, this technology is a cost-effective device used to determine internal injuries or bleeding, and other clinical problems during emergency cases. Meanwhile, the recent helical technology and multidetector features paved ways for the CT improved capabilities in the wide range of disorders like renal calculi, appendicitis, and cardiac and vascular evaluations (Frush, Donnelly, and Rosen, 2003).
CT General Procedure
The medical attendant should ensure that the patient is lying correctly on the CT table (Radiology Info, n.d.). Also, straps and pillows are provided for the patient’s comfort while lying flat on its back so as to avoid unnecessary movement. During the scanning process, patients are encouraged to control their breathing for it affects the quality of the images. At times, children may experience fear of the CT machine and the buzzing sounds during the examination process, thus, parents wearing lead apron or protective gear may accompany the patient (Radiology Info, n.d.).
Children are required to wear loose-fitting garment like an operating gown in the CT scan procedure. Metal objects such as jewelries, retainers, and eyeglasses may affect CT pictures, thus, are not allowed during the examination (Radiology Info, n.d.). Children several hours before the CT scan are generally advised not to take any food stuff or even drink especially if anesthesia will be injected to the patient during the process. Other medical information like previous medication and food allergies should be also given to the attending physician (Radiology Info, n.d.).
Contrast medicines are given intravenously or through enema (Image Gently, n.d.). These medicines, radioactive in nature, concentrate in a specific organ and emit gamma radiation. The emitted gamma rays are then detected and converted to electronic signals that are transformed by computers for an enhanced view of the organs. Contrast substance, although generally safe, are prohibited for patients with kidney problems due to the possibility of aggravating their disorders (Image Gently, n.d.). Also, allergic reactions with these substances are seldom reported. Thus, it is an important matter to determine the medical background of the patient prior to the CT exam. Moreover, especially for children’s cases, drugs for sedation or anesthesia are used to enable children to be relaxed, hence, avoiding unnecessary movements during the CT scan process (Image Gently, n.d.).
Issues and Concerns
The use of CT technology marked a great advancement in diagnostic radiology that requires higher level of radiation exposure than conventional x-ray radiography (Brenner and Hall, 2007). X-ray is a form of ionizing radiation that can cause biological damage by knocking-off the electrons in a particular biomolecule, thereby producing free-radicals. These radicals may interact with DNA molecules or bases of the cell resulting to mutation. Mutation on the other hand, may lead to the production of cancers cells (Brenner and Hall, 2007). This notion was proven by cohort studies conducted on the victims of 1975 Hiroshima bombing in Japan and 400, 000 workers in nuclear industry. These studies found a significant correlation between radiation doses, 30-90 millisievert (mSv) that is tantamount to two or three CT scan sessions, and cancer risk increase (Brenner and Hall, 2007).
It is foreseen in the near future the possibility of endoscopic evaluation to children (Frush, Donnelly, and Rosen, 2003). Thus, the continuous increase in the application of CT technology logically implies augmentation in radiation exposure for medical purposes. This heightened concern of CT pediatric application is due to several accounts: CT uses radiation that may physiologically harm the young ones; CT uses higher dose of radiation as compared with other medical imaging practices; and the wide range of CT application denotes increase in population’s exposure to CT radiation (Frush, Donnelly, and Rosen, 2003).
As compared with adults, children’s organs are still small and much sensitive to biological effects of ionizing radiation. Thus, the whole body exposure of a child in CT radiation instead of target parts only, leads to the absorption of a significantly high amount of radiation. This means higher possibility of fatal cancer development (Frush, Donnelly, and Rosen, 2003). Even though appropriate radiation-level adjustment is being done with pediatric CT scan, there is still a need for machine-sized adjustment. It is also postulated that if children at very young age were exposed to radiation, the cumulative effect then will continue throughout their life time as they come in contact with radiographic devices (Frush, Donnelly, and Rosen, 2003).
Research Findings and recommendations
While the risk of induced cancer and allergic reactions are at hand, the benefits of CT as clinical technology are far more important (Radiology Info, n.d.). Since children’s organs are more sensitive to radiation and the possibility of its cumulative effect throughout their lives, the amount of radiation in CT scan is always kept at lowest possible level. Also, if alternative non-radiation medical diagnostic tools such as ultra-sound or magnetic resonance imaging (MRI) is possible, CT scan should be avoided (Frush, Huda, Brent, 2007). When CT scan is deemed to be the best way to diagnose disorders, radiation exposure should only be limited to the target parts of the body (Radiology Info, n.d.).
Even though some studies reported an increased cancer risk on patients exposed at low level radiation, solid proofs of such in CT patients have not yet established (Image Gently, n.d.). Based on the medical review conducted by experts, the correlation between cancer development and CT radiation exposure is hardly determined but suggested a minimal possibility (Frush, Huda, and Brent, 2007). Moreover, the results of nationally and internationally conducted studies noted that 200-250 among 1000 children without medical radiation exposure may die of cancer. Nevertheless, the reported increase in cancer risk due to CT scan, 0.03-0.05% for the general patient’s population, is very small and does not speak of the risk for a single child (Image Gently, n.d.).
The wide range of CT diagnostic application based on the above discussions really made a great impact on the medical imaging practices. Although, the possibility of cancer development is still at hand, experts suggested that it is of little probability and CT scan advantages are far more important. However, further studies on the impact of CT radiation on chromosomal defects and DNA mutation should be done to provide a solid basis on this matter. For the mean time, let us conform to what experts say on the proper CT scan practices.
Brenner, D.J., and Hall, E.J. (2007). Computed Tomography — An Increasing Source of Radiation Exposure. New England Journal of Medicine, 357:2277-84.
Frush, D.P., Donnelly, L.F., and Rosen, N.S. (2003). Computed Tomography and Radiation Risks: What Pediatric Health Care. Pediatrics, 112:951-957.
Frush, D.P., Huda, W., Brent, R.L. (2007). Radiation Risk to Children From Computed Tomography Radiology. Pediatrics, 120:677-682.
Image Gently. (n.d). What Parents Should Know about Medical Radiation Safety. Retrieved November 23, 2008, from http://www.pedrad.org/associations/5364/files/Image_Gently_8.5x11_Brochure.pdf
Radiology Info. (n.d). Children’s Computed Tomography. Retrieved November 23, 2008, from http://www.radiologyinfo.org/en/info.cfm?pg=pedia-ct