This document summarizes a radiological accident where over 385 patients undergoing CT brain perfusion scans were accidentally exposed to excess radiation doses of 3-4 Gy instead of the expected 0.5 Gy. Technicians intentionally used high radiation levels to get clearer images without proper protocols. This led to consequences like hair loss, skin redness, and increased long-term cancer risks for patients. The accident highlighted the need for specific protocols, training, and oversight of CT equipment to prevent such accidents.

1. Radiological accidents:
CT Brain Perfusion Scans
Overdose.
Moayyad Alssabbagh
MGQ120003
Master of Medical Physics 2012/2013
University of Malaya

2. Radiological accidents: CT Brain Perfusion Scans Overdose
In this Presentation:
• What is CT perfusion scan
• Accident description
• Accident causes
• The consequences, impact and implications
• Lessons learned and recommendations

3. Radiological accidents: CT Brain Perfusion Scans Overdose
• What is CT Perfusion scan:
It’s a kind of diagnostic x-ray scans produce
cross-sectional images or 'slices' of specific
areas of the head.

4. Radiological accidents: CT Brain Perfusion Scans Overdose
• Why:
For stroke test which is the
evaluation of blood flow in the brain.
• Causes:
It happens when blood flow to a
part of the brain stops, which lead
to brain cells die or causing
permanent damage due to lack of
blood and oxygen.
• A stroke is called also a "brain
attack.“

5. Radiological accidents: CT Brain Perfusion Scans Overdose
Accident description
• In Oct. 2009, the first notification was reported
(FDA)
• Patients undergoing computed tomography (CT)
brain perfusion scans were accidently exposed
to excess radiation doses.

6. Radiological accidents: CT Brain Perfusion Scans Overdose
Accident disc. - Cont.
• Some patients reported
obvious signs of excessive
radiation exposure following
their scans, such as hair loss
or skin redness, which called
attention to the problem.

7. Radiological accidents: CT Brain Perfusion Scans Overdose
Problem Description – cont.
• Over 385 patients from six hospitals all in
California alone, were exposed to excess
radiation during CT brain perfusion scans
• Other cases appeared:
– More than 200 patients in a hospital in Los Angeles
– And dozens more at a hospital in Huntsville, Alabama,
were being overdoses too.

8. Radiological accidents: CT Brain Perfusion Scans Overdose
How much radiation dose they received?
• Instead of receiving the expected dose of 0.5 Gy to the
head (depend on patient size, age, condition and
scanner design, etc.), these patients received 3-4 Gy
(approximately eight times) which is in some cases
resulted in hair loss and erythema.

9. Radiological accidents: CT Brain Perfusion Scans Overdose
• How did this happen? (Accident causes)
• An investigation by the Food and Drug Administration
(FDA) was set
• Technicians intentionally used high levels of radiation to
get clearer images. (Recommendation by the companies
that supplied the scanners)
• No manufacturer-defined protocol provided to get
reasonable and appropriate image quality and dose.
• Hospitals modified their own scanning protocols .

10. Radiological accidents: CT Brain Perfusion Scans Overdose
The consequences, impact and implications
• In Addition to hair loss and skin redness, patients experienced
headaches, memory loss and confusion.
• Over time, excessive radiation exposure can place patients at
increased risk for long-term radiation effects, such as risk of
brain damage and cancer.

11. Radiological accidents: CT Brain Perfusion Scans Overdose
• It also has social effects, which may be reflected on the
psychological state of the patient, which can also lead to
work loss.
Mr. Alain Reyes’s co-workers at a shipping
company avoided him, and his boss sent
him home, fearing he had a contagious
disease.

12. Radiological accidents: CT Brain Perfusion Scans Overdose
Lessons learned and recommendations
• The problem may not be detected because the dose is not high
enough to cause radiation injury.
• Regulatory agencies was unaware of those doses but started to
investigate after a news paper brought them to the public attention.
• Providing particular information, protocols and training on brain-
perfusion to all facilities that receiving CT equipments.
A medically-needed CT scan that does not expose the patient to
unnecessary radiation has benefits that far outweigh the radiation
risks

13. Radiological accidents: CT Brain Perfusion Scans Overdose

14. Radiological accidents: CT Brain Perfusion Scans Overdose
• References
• U.S. Food and Drug Administration
 http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm193293
.htm
 http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm185898
.htm
• The New York Times news paper. The New York Times Company
(NYSE: NYT)