Comparison of low dose and standard dose abdominal CT scan in body stuffers.

PURPOSE

Detection of body stuffers is challenging in emergency departments. Because of the small size of baggies, plain radiograph is of little value in most suspects. On the other hand, abdomen CT scan is burdened by high cost and radiation dose. This study was performed to compare the image quality, radiation dose and accuracy of low-dose CT scan in comparison with standard dose.

MATERIAL AND METHODS

In this prospective study, suspected body stuffers who were referred to the radiology department underwent two different protocols of abdominal non-contrast CT scan simultaneously: low-dose (with equivalent dose to conventional abdominal x-ray) and standard dose. Standard dose CT scan was considered as the reference. Low-dose CT scans were evaluated for detection of baggies by two radiologists blinded to the result of standard dose CT. Image quality, noise, dose-length product (DLP) and effective dose (ED) compared between two groups.

RESULTS

The study consisted of 40 patients (33.38 ± 7.4 years). Standard dose CT evaluation was positive in 22 patients (55%). In comparison with standard dose CT scan, low-dose group had a sensitivity of 86%, specificity of 100%, PPV and NPV of 100% and 86%. The accuracy of low-dose CT scan for detection of baggies larger than 1 cm was 100%. However, from the 3 cases that could not be detected with low dose protocol, one had CT features suspected for baggies rupture which was intubated and later deceased. Noise average of low-dose protocol, was approximately 7 times greater than standard dose group, while DLP and ED were 9.7 times less.

CONCLUSION

Low dose CT scan appears to be an appropriate screening method for body stuffers, especially when the baggies are larger than one centimeter. However, in the presence of severe clinical symptoms, a standard dose CT scan will be more helpful due to better image quality especially in suspected ruptured baggies.