Current Trends in Sinonasal Imaging

As endoscopic sinus surgery (ESS) has evolved since its introduction to the United States, so has technology for imaging the sinonasal cavities. Although imaging is most frequently performed for evaluating chronic sinusitis refractory to medical therapy, its uses have expanded beyond inflammatory sinus disease. Multidetector Computed Tomography is the current workhorse for both diagnosis and preoperative planning in prospective ESS patients, while MR imaging remains a complementary tool for evaluating suspected tumors or intracranial and orbital complications of rhinosinusitis. In this article, the authors review current trends and potential future directions in the use of these modalities for sinus imaging.

Computed tomographic analysis of frontal sinus drainage pathway variations and frontal rhinosinusitis

OBJECTIVE

The objective of this study was to radiologically determine frontal sinus drainage pathway variations with respect to superior attachment of uncinate process (SAUP) and their effect on prevalence of frontal rhinosinusitis.

DESIGN

This was a retrospective cohort study.

METHODS

Computed tomography scans of the 919 frontal sinus sides of 460 patients (252 female, 208 male; mean age, 35.1 ± 10.5 years) who were candidates for endoscopic sinus surgery were evaluated retrospectively between August 2012 and January 2013 by 3 radiologists to determine the SAUP types and the presence of frontal rhinosinusitis.

RESULTS

The frontal sinus outflow tract was localized medial to the SAUP in 651 frontal sinus sides and lateral to the SAUP in 268 sides. We determined 3 types (types 7, 8, and 9) of SAUP in addition to 6 types defined in literature. The most common type of SAUP was type 3 (n = 332, 36.1%) followed by type 2 (n = 256, 27.8%) and type 7 (n = 160, 17.4%). Of the evaluated sides, 316 (34.3%) had frontal rhinosinusitis. Frontal rhinosinusitis was more common in the sides where the frontal sinus outflow tract was localized medial to the SAUP than those localized lateral (37.2% vs 27.6%, P = 0.006).

CONCLUSIONS

Endoscopic approach to frontal recess usually requires uncinectomy, and it is necessary to know SAUP to prevent postoperative retained superior portion of the uncinate process. The location of frontal sinus outflow tract on the SAUP affects the prevalence of frontal rhinosinusitis as well. Frontal rhinosinusitis is significantly more common when the frontal sinus outflow tract was localized medial rather than lateral to the SAUP.

LEVEL OF EVIDENCE

2b.

Analysis of the Agger nasi cell and frontal sinus ostium sizes using computed tomography of the paranasal sinuses

The Agger nasi cell (ANC) and the frontal sinus ostium (FO) are important structures that can influence the anatomy and physiology of the frontal recess. The aim of this study was to evaluate the presence and size of ANC and the FO and correlate them according to gender, race and among themselves.

Method

A prospective study with 40 patients who underwent CT of the paranasal sinuses with sagittal reconstruction. Measurements: ANC (APAN) anteroposterior diameter, ANC (CCAN) craniocaudal diameter, ANC (LLAN) side-to-side diameter, anteroposterior diameter of the FO (APFO) and side-to-side diameter of the FO (LLFO).

Results

Twenty-two patients were male and 18 females, mean age 33.7 years. Most patients were white (45%), followed by browns (32.5%), blacks (20%) and asians (2.5%). The ANC was present in 98.7% of patients. There was statistical difference for APAN on females and LLAN on females and on the total sample. There were no differences for all measurements regarding gender, as well as the race. ANC and FO measurements showed positive correlation, but poor or very poor.

Conclusion

The prevalence of ANC in our sample was high and did not show a statistically significant difference for most measurements. The correlation between measurements of ANC and the FO was poor or very poor.

Role of the sagittal view of computed tomography in evaluation of the nasofrontal ducts in frontal sinus fractures

PURPOSE

Frontal sinus fractures are relatively uncommon due to the high-impact force required to produce these. However, their management is quite complex, with the treatment algorithm incorporating many factors in which the status of the nasofrontal ducts is critically important. Traditionally, this has been evaluated by both axial and coronal computed tomographic (CT) scan views. Anatomically, we propose that this is better evaluated by coronal and sagittal CT views. We evaluated the role of sagittal CT scan views in determining the status of the nasofrontal ducts in patients with frontal sinus fractures.

METHODS

A retrospective analysis examining 8 patients with frontal sinus fractures, from August 2004 to January 2008, was performed. Axial, coronal, and sagittal CT scan views were obtained routinely as part of the facial trauma workup. These views were assessed to determine the status of the nasofrontal ducts. The operative findings were also reviewed.

RESULTS

Five of the 8 patients had displaced anterior and posterior table frontal sinus fractures. Of these, 4 required surgical intervention that included addressing the nasofrontal ducts. Two of the 8 patients had displaced anterior table fractures that required no intervention of the nasofrontal ducts. One patient had nondisplaced anterior and posterior table fractures and did not require surgery. The sagittal CT view clearly demonstrated the anatomy of the nasofrontal ducts in all 8 patients, including patients in whom the axial and/or coronal views were questionable. Intraoperatively, where the patency of the nasofrontal ducts was directly evaluated, there was a direct correlation with the sagittal image findings.

CONCLUSIONS

The sagittal CT view provides invaluable information for evaluating the patency of the nasofrontal ducts in frontal sinus fractures. The ability to evaluate the frontal sinus in an anteroposterior dimension (the usual vector of the injury) and in a superoinferior dimension (the anatomic pathway of the ducts) is the reason for this imaging advantage.

Three-dimensional reconstruction based on computed tomography images of the frontal sinus drainage pathway

OBJECTIVE

This study aimed to investigate the utility of three-dimensional reconstructions of paranasal sinus computed tomography data in depicting the anatomy of the frontal sinus drainage pathway.

METHODS

Twenty-nine patients underwent imaging of the sinuses for various clinical indications. Variations in frontal sinus recess anatomy were determined from 0.75-mm thick coronal, axial and sagittal computed tomography images. Three-dimensional, reformatted images were generated from manually segmented volumes of interest. Observations were made on the variation and usefulness of these reconstructions.

RESULTS

Three-dimensional, reformatted images of segmented volumes aided delineation of the spatial relationships of the frontal sinus, frontal sinus drainage pathway, infundibular and meatal direction of drainage, agger nasi cells, ethmoid bulla cells, supraorbital cells, and suprabullar cells.

CONCLUSION

Three-dimensional, reformatted images of frontonasal anatomy enable improved understanding of the frontal sinus drainage pathway anatomy and of the spatial relationships between ethmoid air cells in this region. Such images may provide a useful adjunct to surgical planning and education.

Comparison between three-dimensional and triplanar computed tomography imaging of the frontal recess

BACKGROUND

Despite advances in endoscopic surgical techniques, management of frontal sinus disease remains challenging. Much of this is related to the complex nature of frontal recess anatomy. A thorough understanding of frontal recess anatomy is paramount for the safety and success of frontal sinus surgery. Three-dimensional (3D) computed tomography (CT) may allow surgeons to obtain a more complete preoperative assessment of frontal recess anatomy. The purpose of this study was to determine if reconstructed 3D CT images as an adjunct to conventional triplanar imaging provide additional information regarding the frontal recess anatomy.

METHODS

A prospective study was performed. Two otolaryngologists reviewed the CT scans of 25 patients referred for routine paranasal sinus disease. The findings from review of the triplanar CT images were compared with the findings from review of the 3D reconstructions. Each study was assessed for (1) frontoethmoidal cells, (2) agger nasi cell, (3) subrabullar and frontal bullar cells, (4) intersinus septal cell, (5) superior uncinate process attachment site, and (6) and frontal sinus outflow tract. The examiners rated the usefulness of each study to identify each of the aforementioned anatomic subsites using a modified 5-point Likert scale.

RESULTS

Intersinus septal cells, supraorbital ethmoid cells, and the anterior-posterior dimension of the frontal sinus outflow tract were better defined on the reconstructed 3D CT images.

CONCLUSION

Three-dimensional CT is a useful adjunct to the conventional triplanar studies for the evaluation of frontal sinus and recess anatomy. This technique can define certain anatomic variants more effectively than 2D multiplanar reconstructed images.

Comprehensive management of failed frontal sinus obliteration

BACKGROUND

Treatment of patients with failed frontal sinus (FS) obliteration (FSO) remains an important challenge in the endoscopic era. Advances in endoscopic techniques have facilitated the application of minimally invasive approaches for clinical scenarios that previously required open procedures.

METHODS

A retrospective chart review of patients presenting with failed FSO from January 1, 2001 to June 30, 2007 was performed.

RESULTS

Seventeen patients (mean age, 52.8 years; 10 men and 7 women) presented at an average of 9.7 years from initial FSO. The most common primary presenting symptoms included headache (41.2%) and forehead swelling (23.5%). Seven patients had prior craniotomies and 10 patients had prior endoscopic sinus surgery. All patients underwent surgical exploration; revision procedures were required in 5 patients. Definitive procedures included endoscopic frontal sinusotomy (EFS; 10 patients), endoscopic frontal drill-out (3 patients), revision osteoplastic frontal sinusotomy with obliteration reversal (2 patients), and repeat FSO (2 patients). One patient required revision EFS twice. Initial intraoperative findings included mucocele (13 cases), bone wax (3 cases), fibrous tissue (2 cases), and polypoid mucosa (1 case). All patients had resolution or improvement of their primary presenting signs/symptoms. All FSO reversal patients achieved functional FS patency documented by endoscopy and/or CT scan with mean follow-up of 9.5 months (range, 1.5-30.8 months).

CONCLUSION

Operative exploration should be considered in all patients with persistent or recurrent symptoms and/or signs of failed FSO. In most instances, repeat FSO can be avoided, and a minimally invasive endoscopic strategy can be used successfully.

Computed tomography imaging of the paranasal sinuses: direct versus reformatted coronal images

OBJECTIVE

To evaluate the image quality of coronal reformatted CT images compared with direct coronal CT images.

STUDY DESIGN

Cross-sectional.

SUBJECTS AND METHODS

Patients who underwent paranasal sinus CT scans using both direct coronal images (DC) and axially acquired images with coronal reconstructions (CR) were consecutively enrolled. Two reconstruction groups were evaluated: group CR1 with 1-mm axial collimation and group CR2 with 0.625-mm axial collimation. Scans were presented in a randomized, blinded fashion to two sinus surgeons and a neuroradiologist.

RESULTS

When compared with CR1, DC images had higher image quality for each of five key anatomic landmarks (P < .0001). DC images were more likely to be adequate preoperative imaging (P < .0001). When compared with CR2, improved DC image quality was noted in the majority of key anatomic landmarks. No difference was noted in the "adequacy rating" between the DC and CR2 (0.625 mm) protocols.

CONCLUSION

The 0.625-mm reformatted images were judged to be adequate preoperative imaging. The additional information provided by multiple-image planes make reformatted 0.625-mm axial images an acceptable approach.

Bibliography. Current world literature. Nose and paranasal sinuses

PURPOSE OF REVIEW

Patients with advanced head and neck cancer are being treated with chemo-radiotherapy, and life is being prolonged, with or without persistent disease, for longer than was previously. Hypercalcaemia may present in patients with advanced or disseminated head and neck cancer, and, as such, these patients may present to a larger variety of clinicians for advice concerning their symptoms and illness. Modes of presentation of hypercalcaemia and treatment strategies are reviewed.

RECENT FINDINGS

There were previously few large series of head and neck cancer patients diagnosed with hypercalcaemia, which may or may not have been related to their cancer being treated. Investigations, by way of blood/serum calcium level, may identify such patients. Patients with cancer-related hypercalcaemia have a poor prognosis, but many may respond temporarily to treatment when offered, with an improvement of their quality of life and death.

SUMMARY

Hypercalcaemia should and must be considered in all patients who have or possibly have a diagnosis of a head and neck cancer and who present unwell with symptoms of fatigue, lethargy and somnolence. Investigation must include serum calcium (corrected for serum albumin binding) and parathyroid hormone level. Patients may be treated by a combination of rehydration and bisulphonate therapy until the serum calcium is reduced to a level below 3 mmol/l. The majority of patients diagnosed with hypercalcaemia due to head and neck malignancy die of their diseases in the short term, but some may enjoy a prolongation of life with reasonable quality if diagnosed and treated aggressively.