Objective
Chest pain is one of the most common complaints in the emergency department (ED). Cardiac computed tomography angiography (CCTA) is a frequently used tool for the early triage of patients with low- to intermediate-risk acute chest pain. We present a study protocol for a multicenter prospective randomized controlled clinical trial testing the hypothesis that a low-dose CCTA protocol using prospective electrocardiogram (ECG)-triggering and limited-scan range can provide sufficient diagnostic safety for early triage of patients with acute chest pain.
Methods
The trial will include 681 younger adult (aged 20 to 55) patients visiting EDs of three academic hospitals for acute chest pain or equivalent symptoms who require further evaluation to rule out acute coronary syndrome. Participants will be randomly allocated to either low-dose or conventional CCTA protocol at a 2:1 ratio. The low-dose group will undergo CCTA with prospective ECG-triggering and restricted scan range from sub-carina to heart base. The conventional protocol group will undergo CCTA with retrospective ECG-gating covering the entire chest. Patient disposition is determined based on computed tomography findings and clinical progression and all patients are followed for a month. The primary objective is to prove that the chance of experiencing any hard event within 30 days after a negative low-dose CCTA is less than 1%. The secondary objectives are comparisons of the amount of radiation exposure, ED length of stay and overall cost.
Results
and Conclusion Our low-dose protocol is readily applicable to current multi-detector computed tomography devices. If this study proves its safety and efficacy, dose-reduction without purchasing of expensive newer devices would be possible.

Objective
The overall use of Computed Tomography (CT) continues to grow inside the hospital. Despite CT imaging is a valuable diagnostic technique, the relatively high radiation doses associated with CT compared with conventional radiography have raised health concerns such as future cancer risk. We investigated the awareness level concerning radiation dose and possible risks associated with CT scans in medical personnel (MP).
Methods
and materials: This study was conducted from April to May 2012. Physicians and nurses who worked in emergency department of 17 training hospitals were enrolled in the survey. The questionnaire included the degree of CT scan or radiography affecting health using a 10 numerical rating scale, estimation of the radiation dose for the CT scan compared with one chest radiograph, and the perception of the increased lifetime cancer risk of CT scan.
Results
A total of 354 MP participated in this study. They included 142 nurses, 87 interns, 86 residents, and 39 specialists. Interns were less aware of CT scan or radiography affecting health than other physicians or nurses (4.8±2.7 vs. 5.9±2.7 vs. 6.1±2.7 vs. 6.0±2.2, interns vs. residents vs. faculties vs. nurses, respectively. mean (SD). p < 0.05). There was significant difference in the knowledge about the relative radiation dose of the CT scan for one chest radiograph between doctors and nurses (48.6% vs. 28.9%, doctors vs. nurses, p < 0.05). MPs perceived increased cancer risk from radiation of CT scan.
Conclusions
Medical personnels perceived the radiation risk associated with CT scan, but seems to be insufficient.