Sunday, April 24, 2011

What can we do to reduce overexposure of CT?

  • Educate patients about CT exposure:
    • 90% reported confidence in a medical evaluation that included patient history, a physical exam, blood work, and a CT scan.
  • Dr. Fred Mettler, recommends that patients discuss test ordered with them and the possible amount of radiation given, as well as alternative testing.
  • Tailor the dose to the patient's size.
  • Radiology equipment by the manufactures are placing new protocols to help reduce radiation exposure.
  • Basic radiation protection principles to try to keep dose as low as reasonably achievable.
  • Image Gently campaign is devoted to educating and providing the public with information on the importance of reducing radiation mainly towards CT and children
    • Example: In the case of children, their cells are continually dividing and growing at such a rapid pase, they are more susceptible to cell damange from radiation.
  • Automatic exposure control settings have been implemented to many scanners which this can help reduce dose.
  • Setting protocols and safeguards on CT scanner.
  • Require tracking of the radiation dose levels which should be recorded both on the CT scanner and the patient's medical records.

References:

Patients profess more confidence in exams that include imaging. (2011). RT-image.
Retrieved from http://www.rt-image.com
Dargan, R.S. (2010). Does overexposure get too much exposure in the media. ASRT
            Scanner,46 (6),44-47.
Barnes, E. (2010).  Calif. legislature passes radiation protection bill. Retrieved from
http://www.auntminnie.com/index.aspx?sec=sup&sub=cto&pag=dis&ItemID=91817&wf=1

Saturday, April 23, 2011

What are the benefits of CT scanning?

  • CT scans can be incredibly beneficial with diagnosing and determining many dimensions of pathologies.
  • CT scan of the head can be increasing useful in the realm of acute trauma.
    • Example: CT scans provide more detailed information on head injuries than regular radiographs, and are the best choice for showing changes in bone.
  • CT can show bone, soft tissue, and blood vessels in the same images.
  • Advancements and quick timing of CT scans, patients are seen and diagnosed at a faster rate.
    • Example: Dr. Mike Heller, program director of the Emergency Medicine Residency at St. Luke's hospital in Bethlehem, PA., states, "...That's why a normal CT scan is so useful: in often; it allows you to discharge the patient and virtually assure the doctor that no operative intervention is needed."
  • CT can also be used for biopsies, planning surgery, diagnosing  new tumors, and monitoring old tumors.
    • Example: Physicians use abdomen-pelvis CT scans because they have been demonstrated to increase certainty of diagnosis, decrease the need for emergency surgery and avert up to a quarter hospital admissions.
  • 74% of 383 emergency room patients believe that getting the correct diagnosis outweighed the radiation risk of CT scans.
References:

ER patients favor CT; will tolerated risk. (2010). Diagnostic Imaging, 32 (11). Retrieved
            from http://www.diagnosticimaging.com
Costanzo, V. (2001). Imaging after head trauma: Which method do doctors prefer and
why?. Advance for Imaging & Radiation Oncology.  Retrieved from http://imaging-radiation-oncology.advanceweb.com
Patients profess more confidence in exams that include imaging. (2011). RT-image.
Retrieved from http://www.rt-image.com

Friday, April 22, 2011

Who is at risk?

  • The Archives of Internal Medicine recently published a research study that states, " An estimated 1 and 270 women who underwent CT coronary angiography at the age of 40 will develop cancer from at CT scan."
  • Based on the highest effective dose we observed 20-year-old women who underwent a CT for suspected pulmonary embolism, a CT coronary angiography, or a multihanse abdomen and pelvis CT scan could have a associated increased risk of developing cancer as high as 1 in 80.
    • Example: There was a study done on the amount of radiation received by a subgroup of atomic- bomb survivors who then experienced a significant increase in cancer risk. The mean dose of this group recieved approximately similar to the dose patients recieve from 2 or 3 CT sans.
  • Anyone who received a CT scan will have a risk.


References:

Brenner, D. J., & Hall, P. D. (2007). Computed tomography- an increasing source of
            radiation exposure. The New England Journal of Medicine, 357, 2277-2284.

 
Smith-Bindman, R., Lipson, J., Marcus, R., Kim, K., Mahesh, M., Gould, R.,
Berrington de Gonzalez, A., & Miglioretti, D.L. (2009). Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer. Archives of Internal Medicine, 169(22), 2078-2086.

Wednesday, April 20, 2011

What are some risk of CT scanning?

  • Estimated 3 million scans in 1980 has increased to 62 million scans currently obtained each year in the United States.
  • CT scanning is being used as a screening tool of asymptomatic patients.
  • Physicians are ording CT scans to try to avoid law suits.
  • Human error is common when it comes to overexposure to radiation.
  • Technologist who are not properly trained can over expose patients.
    • Example: A case of a 23 month old boy that was over exposed causing radiation burns to this patient. The case started with the parents just taking their child to the ER after the toddler had fallen out of bed. This exam usually takes between 5-15 minutes depending on the equipment, but in this case it took over an hour. During the exceeded exam time, the patient endured 151scans.
  • When technologist do not properly set the technique, the patients can be overexposed.
    • Example: The Chicago Tribune reports, " Some hospitals and freestanding centers still administer adult-size doses of radiation to children."
  • Machine error that causes over exposure to radiation, the machine may not be calibrated correctly.
    • Example: CT brain perfusions are scans that some facilities use to try to diagnosis strokes. During 2009-2010 about 400 patients have been overexposed during their CT brain perfusion exam causing patients to have hair loss and skin redness.


References:

Brenner, D. J., & Hall, P. D. (2007). Computed tomography- an increasing source of
            radiation exposure. The New England Journal of Medicine, 357, 2277-2284.
Rehani, M., & Frush, D.  (2010). Tracking radiation exposure of patients.  The Lancet,
376 (9743), 754-755. Retrieved from https://login.lib-proxy.usi.edu/login?url=http://search.proquest.com/docview/74976971?accountid=14752
Sanchez, R. (2011).  Bringing down the dose. Retrieved from
http://imaging-radiation-oncology.advanceweb.com/Student-and-New-Grad-Center/Student-Papers/Bringing-Down-the-Dose.aspx
Yin, S. (2010). Children undergo unnecessary CT scans, risk overexposure to radiation.
Retrieved from http://www.fiercehealthcare.com/story/children--CT-scans-risk-overexposure-radiation/2010-08-04

Monday, April 18, 2011

What is Computed Tomography?

What is radiation? 
  • Radiation exposure both manmade and natural can affect people's health.
  • Manmade radiation is the type of radiation received when getting a CT scan or regular x-rays. 
What is Computed Tomography? 
  • Also known as CT or CAT scan. 
  • It is a noninvasive diagnostic exam that is used to diagnosis trauma or other medical conditions. 
  • Obtains images by combining special equipment along with sophisticated computers. 
  • Combination of x-rays, computers, and equipment working together, cross sectional images are obtained during one quick exam.  
  • Most common area scanned in CT are: head, neck, chest, abdomen, pelvic area, spine and extremities. 




  Reference:
American College of Radiology-Radiological Society of North America Committee.
(2010). CT body. Retrieved from http://www.radiologyinfo.org/en/info.cfm?pg=bodyct
What is computed tomography?. (2009). Retrieved from
http://www.fda.gov/RadiationEmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/MedicalX-Rays/ucm115318.htm