Abstract

INTRODUCTION

In the paranasal region, there are radiosensitive organs as thyroid gland and eyes. The dose to be given during paranasal computed tomography (CT) is particularly important in pediatric patients. We sought to answer the question of how much we could decrease the radiation dose during paranasal CT imaging in pediatric patients without compromising on diagnostic quality.

METHODS

Thirty patients (10 females, 20 males) referred for paranasal CT formed two patient groups. Patients were scanned with a 320-row-detector CT device (Aquilion ONE, Toshiba Medical Systems Corporation, Japan). The weight-adjusted standard imaging protocol (100-120 kV, 100-120 mAs) was applied for the first group, the low-dose parameters (100-120 kV, 25-30 mAs) were implemented to the second group. Remaining parameters were kept constant (rotation time: 0.5 s, collimation: 0.5x200-320). Coronal reformat images with 3 mm slice thickness were obtained and sent to picture archiving and computing system following removing patient-dose information. 2 pediatric radiologists evaluated the images independently for the diagnostic quality with a 5-scale scoring system.

RESULTS

The mean DLP value was 326±292 mGy*cm and 30.1±4.4 mGy*cm for the standard and low dose protocols. The effective dose was reduced by 72% in the low-dose protocol (0.6±0.2 mSv and 0.11±0.1 mSv, p<0.05). There was no significant difference of diagnostic quality in image sets (p >0.05). There was good agreement between radiologists in the evaluation of images sets (k=0.87).

DISCUSSION AND CONCLUSION

Paranasal sinus CT may be obtained at two waters graphy dose without compromising on diagnostic quality solely by reducing the tube current in pediatric patients.