Doctors' knowledge of the doses and risks of radiological investigations performed in the emergency department.

OBJECTIVES: To assess emergency doctors' knowledge of radiation exposure doses and risks, and the increasing use of radiological investigations in emergency medicine practice is very concerning because of the associated risks of cancer. METHODS: Doctors from different specialties and with different levels of training working in emergency departments of 8 hospitals in Jeddah, Kingdom of Saudi Arabia, filled out a questionnaire. Participants estimated the radiation doses of different imaging modalities and answered questions regarding possible associated risks. Results: One hundred seventy-one doctors returned completed questionnaires. The overall correct dose estimation rate was 20.8%. Doses were more correctly estimated by consultants versus specialists and residents (p=0.007), and by emergency physicians versus doctors from other specialties (p=0.05). The correct answer rate was insignificantly higher among doctors with formal training on radiation protection (p=0.065). The overall correct answer rate was unsatisfactory for 4 questions assessing physicians' knowledge of risks. Questions about the lifetime risk of cancer due to ionizing radiation were more correctly answered by consultants versus residents and specialists (p=0.05). Specialists were more knowledgeable about the risk of imaging on fetuses (p=0.05). Doctors with formal training answered 3 out of 4 questions more correctly than doctors without formal training, but no difference existed between them regarding imaging modalities, that they selected for pregnant patients (p=0.297). Conclusion: Doctors working in emergency departments had poor knowledge about radiation doses and risks. This issue warrants urgent attention.

Coronary artery calcification detected by PET/CT scan as a marker of myocardial ischemia/coronary artery disease.

BACKGROUND: There have been no data with regard to the relationship between coronary artery calcification (CAC) detected with positron emission tomography (PET)/computed tomography (CT), as incidental findings, and myocardial perfusion single photon computed tomography (MPS) results in patients with cancer. OBJECTIVES: The main objective of this study was to investigate the relationship between CAC detected on the CT component of PET/CT and abnormal MPS in patients with cancer before oncologic surgery. METHOD: A total of 157 patients without known coronary disease and clinically proven indication for PET/CT underwent PET/CT and MPS as a routine preoperative workup. PET/CT and MPS were performed within 3 months. The frequency of abnormal MPS was compared with the presence or absence of CAC. CAC was evaluated visually. RESULTS: Among 81 patients with no CAC, MPS results were normal in 71 patients (88%). Only 10 patients (20%) with no CAC had abnormal MPS (P<0.005) results. However, in the total patient population with visually detectable CAC (76 patients), MPS results were normal in 36 patients (47%) and abnormal in 40 patients (53%) with no statistically significant value. CAC and diabetes mellitus were the most potent predictors of abnormal MPS by multivariable analysis. CONCLUSIONS: Visual detection of CAC in the CT component of PET/CT is a strong predictor of MPS results. The presence of CAC is associated with a high likelihood of abnormal MPS, but the absence of CAC is rarely associated with abnormal MPS. These findings imply a potential role for applying routine visual CAC detection in the CT component of PET/CT and might obviate unnecessary MPS indications in the preoperative evaluation in patients with cancer.