RT Journal Article
SR Electronic
T1 Optimization of techniques in screening CT of the sinuses.
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 849
OP 854
VO 12
IS 5
A1 R Babbel
A1 H R Harnsberger
A1 B Nelson
A1 J Sonkens
A1 S Hunt
YR 1991
UL http://www.ajnr.org/content/12/5/849.abstract
AB The number of screening examinations of the sinuses performed with CT has markedly increased owing to the widespread and increasing use of endoscopic sinonasal surgery. We reviewed scans from 500 patients who had screening CT examinations of the sinuses for preendoscopic evaluation of inflammatory sinonasal disease to better define an optimal imaging protocol. Three aspects of direct coronal imaging of the paranasal sinuses were investigated: (1) preparation of the patient prior to the examination; (2) technical factors of the CT study, including positioning of the patient, optimal coronal angle, slice thickness, and CT exposure factors; and (3) data display. Our experience indicates that pretreatment of the patient with maximal medical therapy enables the best preendoscopic definition of anatomy, disease pattern, and nonreversible disease component for the treating surgeon. CT technical factors are optimized with scanning in the prone position with thin (3-mm) sections obtained through the anterior paranasal sinuses. This allows optimal visualization of the ostiomeatal unit. The remaining posterior portions of the sinuses are adequately imaged with thicker slices (5 mm). The coronal scan angle used is less critical. Exposure factors (mAs) can be reduced dramatically without image compromise. Data display is optimized when the bone algorithm is used to acquire the data and with image display at intermediate window center and width level. Use of the techniques outlined in this article results in a cost-effective yet diagnostic scan of the sinuses with decreased radiation exposure to the patient.