Certification Exams

In some countries, including England and Australia, graduating from an accredited program is the requirement for entry to practice for a Radiological Technologist. Alternately, in Canada, the US, and other countries, certification exams are required to be a practicing Technologist.

In Canada, all students graduating from Canadian accredited programs must write the Canadian Association of Medical Radiation Technologists (CAMRT) certification exam in order to practice in Canada. The exam is a competency based exam, written in two 3-hour sessions, with a total of 250 multiple choice questions (CAMRT, 2009). In the US, the American Registry of Radiologic Technologists (ARRT) provides certification in Radiography. Candidates write a 220 multiple choice question exam. (ARRT, 2010). In the Philippines, graduates of a recognized school with a Baccalaureate degree in radiologic technology sit for the registry exam (PRC, 2010).

The big question for any student is how to prepare for this extremely important exam.

The CAMRT provides, in addition to the study guide, an online practice exam. You can take this exam by going to http://camrt.protraining.com/ and registering. There are practice exams for all of the CAMRT professional streams including Radiological Technology, Nuclear Medicine, Radiation Therapy, and Magnetic Resonance Imaging.

Today, Blogger and Instructor, Hariette made a post on her blog "Radiology 101" about a Radiologic Technology review program. The program consists of lecture-style review over a period of two months to prepare students for their board examination.

Another approach is to use the study guides published, for example Mosby's Comprehensive Review of Radiography or Lange Q&A: Radiography Examination, which are written based on the ARRT examination. These guides receive mixed reviews, some readers saying they did not contain all the required information for the exam, while others say they were a big help in their studies (Amazon, 2004). I bought the Mosby's book last year thinking it might be a little help studying for my CAMRT exam this spring. The book is useful in that it provides multiple-choice questions to practice with. However, the book does not provide in depth or complete information as I would assume is needed to pass the CAMRT exam. There are currently no published study guides for the CAMRT examinations.

Early after the discovery of X-rays, one journalist suggested that X-rays could be used to directly project radiographic images into the minds of students (Dewing, 1962). If only.

Any wise words of advice on preparing for these exams?

AART. (2010). American Registry of Radiologic Technologists. Retrieved from https://www.arrt.org/

Amazon. (2004). Mosby's Comprehensive Review of Radiography: Customer Reviews. Retrieved from http://www.amazon.ca/Mosbys-Comprehensive-Review-Radiography-Complete/dp/0323054331/ref=pd_sim_b_3

CAMRT (2009). Prep Guide. Retrieved from http://www.camrt.ca/english/certification/pdf/Prep-guide.pdf

Dewing, S. B. (1962). Modern Radiology in Historical Perspective. Springfield, IL: Charles C Thomas Publisher

PRC. (2010). Republic of the Philippines Professional Regulation Commission. Retrieved from http://www.prc.gov.ph/default.asp

Towards the Standardization of Exposure Indices

Exposure index is a tool used by Radiological Technologists in digital radiography to assess radiographic exposure. Exposure index is, broadly speaking, a measure of the amount of exposure detected by the image receptor. Accordingly, it depends on the mAs and kV used, the detector area irradiated, and the beam attenuation (Bontrager & Lampignano, 2005). 

Under the reign of film-screen radiography, exposure is directly related to the final density of the image. A measure of exposure is not needed because it is plainly evident on the image. In digital radiography, overexposed images may not be dark and underexposed images may not be light. Post processing ultimately controls the brightness of the image on the monitor. Exposure thus becomes evident only through the noise in the image, more noise coinciding with underexposure. Because of the low resolution displayed by the monitor used by the Radiological Technologist in assessing the image, noise level is sometimes not evident. The exposure index is the indication of an appropriate exposure and resultant image quality (AAPM, 2009)

Depending on what system you use, the concept of an exposure index is represented by one of many terms.  Sensitivity number, log median exposure (lgM), f-number, reached exposure (REX), and detector exposure index (DEX) are just a few used terms, demonstrating the miscellany in nomenclature. It comes as no surprise that all of these ways of describing exposure are actually different, either in the information conveyed or the way it is described (Carlton & Adler, 2005).

Fujifilm's S-number is the oldest exposure indicator, closely mimicking the "speed class" system used in film-screen radiography. Exposure index increases with a decrease in exposure. Kodak's exposure index (EI) is representative of the average pixel value for the clinical area of interest. A change of 300 in the EI indicates a change of a factor of 2 in the exposure. Agfa CR utilizes the "lgM" or log median exposure. A change in the lgM by 0.301, or a logarithm of 2, indicates a change of a factor of 2 in the exposure. Philips EI is inversely proportional to air kerma, and the scale used is represented in bigger discrete steps (200, 250, 320…) which requires a 25% change in exposure per step (AAPM, 2009). This illustrates the large differences in the source and calculation of the exposure indicator.

The American Association of Physicists in Medicine (2009) suggest the standardization of an indicator of exposure to the detector. Not only would it be useful to monitor differences in exposure between systems in a given institution, but it would provide unambiguous information for Technologists working with more than one system. A standardized exposure indicator should, according to the AAPM (2009), reflect the radiation exposure to the detector and image noise. 

The deviation index (DI) is the proposed index to be displayed to the Radiological Technologist immediately after every exposure. The DI is a measure of the relative deviation from the targeted value for a particular body part and view (AAPM, 2009).

American Association of Physicists in Medicine. (2009). An Exposure Indicator for Digital Radiography. Retrieved from http://www.aapm.org/pubs/reports/rpt_116.pdf

Bontrager, K. L., & Lampignano, J. P. (2005). Textbook of radiographic positioning and related anatomy (6th ed.). Elsevier Science. 

Carlton, R. R. & Adler, A. M. (2005). Principles of radiographic imaging: An art and a science. Delmar Learning. 

Marie Curie in Radiography

Marie Curie is best known for her work in radioactivity. During World War I Curie, through conversation with an eminent radiologist Dr. Henri Beclere, recognized that radiographic equipment was rarely used in the French military. When it was used, the equipment was usually in poor condition and was being used by untrained persons (Quinn, 1996). Curie stopped her work in radioactivity and started working where she was needed most, in radiology (Dewing, 1962).

The French government did not give this work any consideration. She was required to scrounge money, equipment and materials to continue the project. Manufacturers of x-ray equipment were harassed until they would provide what was needed (Dewing, 1962). In fact, Curie faced many obstacles in this endeavour, being a woman, a volunteer, and offering a service that was not offered by the military (Quinn, 1996).

Curie took radiography equipment that was going unutilized in laboratories or in the offices of doctors who had been mobilized, and installed them in hospitals. Marie knew more about medicine than most of her colleagues in physics and chemistry, as her siblings were both medical doctors. Working in radiology allowed her to use her scientific knowledge to aid those who were wounded in war (Quinn, 1996).

While working in hospitals in Paris and from radiologist Dr. Beclere, Curie learned the fundamentals of radiography. With this new knowledge, she taught volunteers of radiological technique and anatomy (Quinn, 1996). She converted her Institute of Radium into a school for radiologic technicians. Between 1916 and 1918, she personally trained 150 female technicians, in addition to American soldiers (Kelves, 1997; Dewing, 1962).
 

Curie (centre) with four of her students (Library of Congress, 1910-1915).

Marie and her seventeen year old daughter, Irene, worked to convert ordinary automobiles into mobile radiography cars, which were called "les voitures radiologique" and sometimes "petits Curies" by the French soldiers. The car's motor powered the x-ray tube. The cars would be packed with all necessary equipment and were embarked by a doctor, a technician, and a driver. Marie learned to drive with the intent of not requiring a chauffeur. She thought that a good team works inter-professionally and transcends their roles (Quinn, 1996; Kelves, 1997).
 

Curie in a mobile radiography car (Centre of History for Physics, 2010)

When the car arrives at the locale of the wounded, the team, within half an hour, unloads and installs the equipment. Then, the team gets to work, where fluoroscopy and radiography are used to examine the patient. Observations are recorded. Then, the team packs up and returns to base to get to work on their next case (Quinn, 1996).

Over the course of the war, Curie helped install 200 x-ray units for the French and Belgian armies, and provided 20 more radiography cars. Before WWI, radiology was on the fringes of medical practice. The mass involvement of radiography throughout the first world war brought radiology to the forefront of medicine (Kelves, 1997).

Center of History for Physics. (2010). Help for the wounded. Retrieved from http://www.aip.org/history/curie/brief/05_campaigns/campaigns_1.html

Dewing, S. B. (1962). Modern Radiology in Historical Perspective. Springfield, IL: Charles C Thomas Publisher

Kelves, B. (1997). Naked to the Bone: Medical Imaging in the Twentieth Century. New Brunswick, NJ: Rutgers University Press

Library of Congress (1910-1915). Marie Curie and four of her students. Retrieved from http://nobelprize.org/nobel_prizes/physics/laureates/1903/marie-curie-photo.html 

Quinn, S. (1996). Marie Curie: a life. United States of America: Da Capo Press

CBLB502: Radiation Protection Drug

On January 28, 2010, Cleveland BioLabs, Inc. announced that the European Patent Office granted them a patent, "Methods of Protecting Against Radiation Using Flagellin". This patent had already been granted in the United States and 11 other countries. This patent covers the method of protecting a mammal from radiation using flagellin or its derivatives, like CBLB502  (Levine, 2010).

CBLB binds to Toll-like receptor 5 (TLR5) and turns on the nuclear factor-κB signalling pathway. This results in the induction of factors that protect cells like apoptosis inhibitors and promotes tissue regeneration through cytokines. The drug also inhibits the p53 tumour suppression pathway which is a mechanism by which cancer cells resist radiation.

Radiation is toxic because of the massive apoptosis it causes in radiosensitive organs. CBLB502 operates on the principle that radioprotection is achieved through suppression of apoptosis. CBLB502 protects healthy cells from the harmful effects of radiation, all while allowing the tumours to be better affected by the radiation. 

High-dose ionizing radiation can cause acute radiation syndromes involving the hematopoietic system and the gastrointestinal tract. CBLB502 was effective as a radioprotectant in 19 monkeys who were subjected to 6.5 Gy total body irradiation, which is a lethal dose for 70% of monkeys (LD70). The monkeys received an injection of 0.04mg of CBLB502 45 minutes before the irradiation. This reduced the onset of radiation-induced mortality by 10 days and increased the 40-day survival rate from 25% to 64%. The 7 monkeys who survived 40 days post-irradiation demonstrated minor damage to major hematopoietic and lymphoid organs, the bone marrow, spleen and thymus (Burdelya, et al., 2008). 

Burdelya, et al. (2008) assessed CBLB502 as an adjuvant for anticancer radiotherapy. CBLB502 was injected into mice 1 hour before each of three daily treatments of 4 Gy total body irradiation. The treatment completely prevented radiation-induced mortality or significantly protected against it. The implication of this is that the drug could be used in patients receiving radiotherapy to protect against the adverse effects. The adverse effects of radiation must be managed by limiting the dose applied. If the adverse effects were eliminated, higher doses could be used. 

Another interesting application of the drug is treatment post lethal irradiation. Mice who were exposed to lethal radiation (13 Gy) were rescued by CBLB502 treatment 6 months later. The mice showed signs of radiation-induced tissue damage but had no signs of cancer (Burdelya, et al., 2008).

CBLB502 is still in the early stages of development but it could allow for safer and more effective radiation therapy and protection in overexposures to radiation.

Levine, R. (2010, January 28). Cleveland BioLabs granted European patent for radiation protection drug CBLB502. CNN. Retrieved from http://money.cnn.com/news/newsfeeds/articles/marketwire/0581289.htm

Burdelya, L. G., Krivokrysenko, V. I., Tallant, T. C., Strom, E., Gleiberman, A. S., Gupta, D., … Gudkov, A. V. (2008). An agonist of toll-like receptor 5 has radioprotective activity in primate models. Science, 320(5873), 226-230. Retrieved from http://www.sciencemag.org.ezproxy.library.dal.ca/cgi/content/full/320/5873/226