Imaging After Sinonasal Surgery

Posttreatment imaging evaluation of sinuses encompasses a wide gamut of procedures, ranging from endoscopic procedures for sinonasal inflammatory diseases to markedly radical surgeries for malignant neoplasms (with or without reconstructions), as well as providing access for surgeries involving the anterior and central skull base. Advances in both techniques and devices have expanded the use of endoscopic approaches in managing both benign and malignant lesions, in addition to being the primary surgical method for treating all medically refractive sinonasal inflammatory disorders. Familiarity with the complex anatomy in the sinonasal region and knowledge of the various procedures is indispensable in interpreting these imaging studies.

Repeated sinus CT imaging after recent head imaging

OBJECTIVES

Excessive use of sinus CT is a significant problem in medical imaging, resulting in unnecessary costs and radiation exposure. This study assesses frequency of sinus CT performed after recent head imaging has already adequately evaluated the sinuses.

METHODS

A retrospective search of the PACS database of an academic medical center was performed to identify cases of sinus CT imaging in 2017. Cases were excluded if sinus CT was performed related to trauma, tumor, operative evaluation, or acute infection other than sinusitis (orbital cellulitis, intracranial abscess). Studies with separate imaging covering the sinuses ordered at the same time as sinus CT or performed previously within 4 weeks were identified and clinical information was recorded.

RESULTS

Of 735 sinus CTs performed, 19 (5%) had same-day head imaging and 30 (8%) had previous head imaging within 4 weeks, adding up to a cumulative 13% of cases with recent head imaging. The average patient age was 42, with 13 pediatric cases. Of ordering providers, residents ordered the highest percentage of sinus CTs with same-day head imaging (84%) and previous imaging within 4 weeks (63%). The sinuses were described in all head CT radiology reports, while 10 of 12 brain MRI reports did not mention the sinuses.

CONCLUSION

In one year, 13% of patients receiving sinus CTs at our institution had recent head imaging. A focused education effort for ordering providers to avoid repeating sinus imaging, and for radiology to comment on sinuses on head imaging, may reduce unnecessary sinus CTs.

Morphological concordance between CBCT and MDCT: a paranasal sinus-imaging anatomical study

PURPOSE

Cone-beam computed tomography (CBCT) is an imaging technique, first developed for use during oral and pre-implant surgery. In sinonasal surgery, CBCT might represent a valuable tool for anatomical research given its high spatial resolution and low irradiation dose. However, clinical and anatomical evidence pertaining to its efficacy is lacking. This study assessed the morphological concordance between CBCT and multislice detector computed tomography (MDCT) in the context of sinonasal anatomy.

METHODS

We performed an anatomical study using 15 fresh cadaver heads. Each head underwent both CBCT and MDCT. Two independent reviewers evaluated 26 notable anatomical landmarks. The primary outcome was the overall morphological concordance between the two imaging techniques. Secondary objectives included assessment of inter-rater agreement and comparison of the radiation doses received by different parts of the anatomy.

RESULTS

Overall morphological concordance between the two imaging techniques was excellent (>98 %); the inter-rater agreement for CBCT was approximately 97 %, which is highly similar to MDCT, but achieved using a significantly decreased irradiation dose.

CONCLUSION

Our preliminary study indicates that CBCT represents a valid, reproducible, and safe technique for the identification of relevant sinonasal anatomical structures. Further research, particularly in pathological contexts, is required.