Micro-dose Paranasal Computed Tomography is Valuable When Evaluating Diseases of the Paranasal Sinuses

Aim: We explored whether a reduction in the radiation dose affected the quality of diagnostic images generated using third-generation dual-source computed tomography (CT) running advanced third-generation iterative reconstruction software. Methods: From February to May 2015, 72 consecutive patients aged 16 to 64 years with clinically suspected sinusitis were randomly and prospectively enrolled and divided into two groups (standard or micro-dose CT). Anatomical landmarks and mucosal structures were independently evaluated by a radiologist and an otorhinolaryngologist using a four-point grading scale. Mean scores were calculated and compared. Results: All images were of diagnostic quality. The mean effective radiation dose was significantly lower in patients evaluated via the micro-dose protocol (group 2) than in those evaluated using the standard protocol (group 1) (p<0.05). The mean anatomical scores showed that all landmarks were very well-defined, with the exceptions of the uncinate attachment point and the ethmoid foramen (used to identify the ethmoid artery). The Wilcoxon signed rank test revealed no significant difference between the mean scores of the two observers for either group (p>0.05). Conclusion: The radiation dose to the paranasal sinus delivered during CT in patients with suspected sinusitis can be reduced to 0.003 mSv using third-generation dual-source CT running advanced iterative reconstruction software.