Computed tomography anatomy of the paranasal sinuses and anatomical variants of clinical relevants in Nigerian adults

Ultra-low-dose photon-counting CT of paranasal sinus: an in vivo comparison of radiation dose and image quality to cone-beam CT

PURPOSE

This study investigated the differences in subjective and objective image parameters as well as dose exposure of photon-counting CT (PCCT) compared to cone-beam CT (CBCT) in paranasal sinus imaging for the assessment of rhinosinusitis and sinonasal anatomy.

METHODS

This single-centre retrospective study included 100 patients, who underwent either clinically indicated PCCT or CBCT of the paranasal sinus. Two blinded experienced ENT radiologists graded image quality and delineation of specific anatomical structures on a 5-point Likert scale. In addition, contrast-to-noise ratio (CNR) and applied radiation doses were compared among both techniques.

RESULTS

Image quality and delineation of bone structures in paranasal sinus PCCT was subjectively rated superior by both readers compared to CBCT (P < .001). CNR was significantly higher for photon-counting CT (P < .001). Mean effective dose for PCCT examinations was significantly lower than for CBCT (0.038 mSv ± 0.009 vs. 0.14 mSv ± 0.011; P < .001).

CONCLUSION

In a performance comparison of PCCT and a modern CBCT scanner in paranasal sinus imaging, we demonstrated that first-use PCCT in clinical routine provides higher subjective image quality accompanied by higher CNR at close to a quarter of the dose exposure compared to CBCT.

Evaluation of Anatomical Variations Associated with Chronic Rhinosinusitis by Computed Tomography of Paranasal Sinuses

BACKGROUND

Chronic rhinosinusitis (CRS) is a syndrome with multifactorial aetiology. Amongst which, anatomical variations studied by computed tomography of paranasal sinuses (CT PNS) had a high incidence which varied between 64.0% and 99.8%10. Due to such high incidence, this study is undertaken to assess the various anatomical variations and their significant association in CRS.

METHOD

A prospective observational study was conducted in 70 CRS patients and were subjected to CT PNS. CT PNS is studied to know the various anatomical variations & other CT findings causing CRS and then findings noted down, tabulated and statistical analysis done.

RESULTS

All 70 CRS patients evaluated by CT PNS had one or more anatomical variations along with other findings like fungal sinusitis in 6 patients, dentigerous cyst and inverted papilloma in 1 case each. The anatomical variations observed in our study were septal deviation(62.8%), concha bullosa(52.8%), agger nasi(51.4%), pneumatized crista galli(47.1%), hyperpneumatized bulla(40%), suprabullar cells(37%), septal spur(34.3%), paradoxically curved middle turbinate(34.2%), supra orbital cells(32.8%), haller cells(31.4%), septal pneumatization(17.1%), pneumatized uncinate(13%), interfrontal septal pneumatization(13%), maxillary septations(10%), maxillary sinus hypoplasia(7.1%), frontal hypoplasia(5.7%), uncinate attached to lamina papyracea(40%), uncinate to middle turbinate(11%), uncinate to skull base(7.9%), free uncinate(41%), frontal cells type 1;2;3;4 (36%);(30%);(20%);(38.5%), onodi cells(27.1%), pneumatized anterior clinoid process(18.5%), lateral recess(15.7%), sphenoid septations attached to optic nerve(10%) and carotid(2.8%), pneumatized superior turbinate(1.4%), Sellar; Pre sellar; Post sellar sphenoid(42.8%);(5.7%);(51.4%). In our study only anatomical variations around the maxillary & Frontal sinus showed significant association with CRS.

CONCLUSION

Anatomical variations around the anterior group of sinuses have a significant association with CRS.

Volumetric Changes of the Paranasal Sinuses with Age: A Systematic Review

BACKGROUND

There are four pairs of paranasal sinuses: maxillary, ethmoidal, frontal, and sphenoidal. It is common to see changes in size and shape throughout life, so understanding the effect of age on sinus volume can help in radiographic studies and in planning dental and surgical procedures in the sinus-nasal region. The aim of the present systematic review was to perform a qualitative synthesis of available studies which assess the volumetric characteristics of the sinuses and their changes according to age.

MATERIALS AND METHODS

The present review followed PRISMA 2020 guidelines. A systematic advanced electronic search was performed in five databases (Medline (via PubMed), Scopus, Embase, Cochrane, and Lilacs) in June-July 2022. Studies that assessed the volumetric changes of paranasal sinuses with age were eligible for inclusion. A qualitative synthesis of the methodology and results of the included studies was performed. Quality assessment was performed using the NIH quality assessment tool.

RESULTS

A total of 38 studies were included in the qualitative synthesis. Most authors who studied the maxillary and ethmoidal sinuses concluded that it begins its development from birth until the maximum peak of growth, from which it begins to decrease in volume with age. Results regarding the volumetric changes of the frontal and sphenoidal sinuses are mixed.

CONCLUSIONS

Based on the results of the studies included in the present review, it can be concluded that the volume of the maxillary and ethmoidal sinus appears to decrease with age. Conclusions on the volumetric changes of the sphenoidal and frontal sinuses require further evidence.

Are maxillary sinus variations related to maxillary sinus diameters?

OBJECTIVES

The reasons why the maxillary posterior region is challenging for dentists are its structure and anatomical variations. For this reason, it is necessary to have complete knowledge about the anatomy of this region. In dentistry, necessary information for the desired evaluation in this region can be provided by CBCT. The fact that it provides a three-dimensional evaluation and has measurement reliability emphasizes its importance in surgical applications. The septa, haller cell, and accessory ostium are variations of the maxillary sinus. There are few studies in the literature examining the relationship between maxillary sinus diameters and its variations. The aims of this study are to determine the prevalence of maxillary sinus variations and the average of maxillary sinus diameters, to examine their relationships according to age and gender, and to evaluate the effects of maxillary sinus diameters on variations.

METHODS

In this retrospective study, CBCT images of 212 patients were examined. The examined CBCT images were analysed and recorded in more than one section. Descriptive statistics, chi-square tests, independent t test, one-way Anova tests were used to evaluate the data.

RESULTS

As a result, a statistically significant difference was observed between the variations, gender and age groups in terms of morphometric characteristics of the maxillary sinus. The most common variation was observed to be accessory ostium.

CONCLUSIONS

The rate of patients with at least one anatomical variation was 77.8%. For this reason, a detailed analysis should be performed to avoid complications before surgical procedures are performed in the area.

Variations of the Nasal Septum in Adult Nigerians: Computed Tomography Study

Introduction  The morphological variants of the nasal septum have been implicated in sinus pathology and pose a challenge during endoscopic surgeries. Objective  The present study aimed at evaluating the prevalence of nasal septum variants in adult Nigerians. Methods  The present study was performed at the Radiology Department of Delta State University Teaching Hospital, Nigeria, following ethical approval. Brain computed tomography (CT) scan images of 336 adults were evaluated for nasal septum variants. The angle of the deviated nasal septum was measured, and the severity was classified. Data were analyzed using IBM SPSS Statistics for Windows, version 23.0 (IBM Corp., Armonk, NY, USA). The angle of deviation was presented in means and standard deviation. Frequencies of the variants were presented in percentages. The Student t -test was used to compare the angle of deviation, while the chi-squared test was used to compare the frequencies in the different groups. A p-value < 0.05 was considered statistically significant. Results  The prevalence of straight and deviated nasal septum was 59.5% and 40.5%, respectively. Deviation was predominant in females (46%) and, more frequently, of moderate severity (75%). The angle of deviation was significantly larger in males (12.55 ± 2.99°) than in females (11.13 ± 2.41°; p  = 0.003). Nasal spur had a prevalence of 11.9%, and its coexistence with deviated nasal septum was observed in 5.06%. Septal pneumatization was seen in 10 patients (3%). Conclusion  Deviation of the nasal septum occurred more in females and toward the left; however, the angle of deviation was significantly higher in males. Nasal septal spur and pneumatization were the least prevalent variants.

Radiological anatomical variations of the lateral nasal wall and anterior skull base amongst different populations: A systematic review and meta-analysis

OBJECTIVES

To determine the anatomical variations of the lateral nasal wall and anterior skull base amongst populations in different geographical regions.

DESIGN

Systematic review and meta-analysis.

METHODS

Using PRISMA guidelines, SCOPUS and PUBMED databases were searched from inception until 1 March 2022. The regions and populations identified were from Europe, Asia, Middle East, Australia-New Zealand-Oceania, South America, North America and Africa. Random-effects model was used to estimate the pooled prevalence with 95% confidence intervals (CIs). Heterogeneity was assessed using the I² statistic and Cochran's Q test.

MAIN OUTCOME MEASURES

Anatomical variations of the lateral nasal wall and anterior skull base confirmed by computed tomography scan.

RESULTS

Fifty-six articles were included with a total of 11 805 persons. The most common anatomical variation of the ostiomeatal complex was pneumatization of the agger nasi (84.1%), olfactory fossa was Keros type 2 (53.8%) and ethmoids was asymmetry of the roof (42.8%). Sphenoethmoidal and suprabullar cells have a higher prevalence in North Americans (53.7%, 95% CI: 46.00-61.33) while asymmetry of ethmoid roof more common in Middle Easterns (85.5%, 95% CI: .00-100). Bent uncinate process has greater prevalence in Asians while supraorbital ethmoid cells and Keros type 3 more common in non-Asians. The overall studies have substantial heterogeneity and publication bias.

CONCLUSION

Certain anatomic variants are more common in a specific population. The 'approach of analysis' plays a role in the prevalence estimates and consensus should be made in future studies regarding the most appropriate 'approach of analysis' either by persons or by sides.

Nasal septal anatomical variations among Saudi population and their possible coincidence with sinusitis: a computed tomography scan study

The nasal septum is a crucial supporting factor for the nasal cavity and may develop several anatomical variants including septal deviation, spur and pneumatization. These variants could be associated with a higher incidence of sinusitis due to structural and functional alterations. So, the aim of this study was to assess the prevalence of nasal septal deviation (NSD), nasal septal spur (NSS) and nasal septal pneumatization (NSP) among the Saudi adult population and their links with the incidence of sinusitis by using computed tomography (CT). A retrospective study was achieved over a twenty-two months period on 681 adult Saudi subjects (420 males and 261 females) aged 20 years or older, referred for coronal CT evaluation of the paranasal sinuses. NSD and NSS were significantly more prevalent in males than females (80.0% vs. 67.4% respectively for NSD, and 34.5% vs. 24.9% respectively for NSS), while there was no statistical difference in frequency of NSP regarding gender (P=0.670). The incidence of sinusitis was significantly higher in presence of NSD and/or NSS (P<0.001 for both). On the contrary, NSP was not associated with a significant increase in the prevalence of sinusitis (P=0.131). In conclusion, NSD and NSS are more prevalent in males than females among the Saudi population with no statistical difference between both genders regarding the presence of septal pneumatization. Furthermore, sinusitis is more prevalent with the occurrence of NSD and NSS, and not related to the incidence of NSP.

Anatomical relationship of pterygoid process pneumatization and vidian canal

Introduction

The vidian canal acts as landmark for the identification of the petrous carotid artery, especially during extended endoscopic endonasal approaches in cranial base surgeries. In order to localize the canal and to understand the relationship of pneumatization of pterygoid process to the type of vidian canal, this study was designed.

Objectives

The objective was to describe the anatomical relationship of pneumatization of the pterygoid process with types of vidian canal. The length of vidian canal, relationship to medial plate of pterygoid process and relationship to the petrous part of internal carotid artery were evaluated.

Methods

Head computer tomography scans of 52 individuals for suspected paranasal pathology were studied. The degree of sphenoid sinus pneumatization, pterygoid process pneumatization and types of vidian canal (type 1, 2 and 3) were noted. The length of vidian canal, distance from the plane of medial pterygoid plate and relation of vidian canal to the junction of petrous and Gasserian (ascending) part of internal carotid artery was noted.

Results

46 (92%) sphenoid sinuses were of the sellar variety. Out of 104 sides that were studied, 57 sides demonstrated a pneumatised pterygoid process and 47 were not pneumatised. In 49 sides (47.1%) the vidian canal was on the same plane as that of the medial pterygoid plate in the coronal section. The vidian canal partially protruded into the sphenoid sinus (type 2) was the most common type (50.9%), found both on right and left sides. There is a statistically significant association between the pterygoid process pneumatization and occurrence of type 2 and type 3 vidian canal configuration. The average length of the vidian canal was 16.16 ± 1.8 mm. In 96 sides, the anterior end of vidian canal was inferolateral to petrous part of internal carotid artery in the coronal plane.

Conclusion

Pneumatization of the pterygoid process indicates either type 2 or type 3 vidian canal configuration.

A Case Report of Aggressive Chronic Rhinosinusitis with Nasal Polyps Mimicking Sinonasal Malignancy

Introduction

Cases of extensive nasal polyps rarely occur and may mimic more aggressive lesions of the nose and paranasal sinuses. A case of extensive nasal polyposis with unusually aggressive behavior and its management is presented.

Presentation of Case

A 27-year-old male patient visited the emergency department of a tertiary center, complaining of recurrent episodes of epistaxis. The patient presented with a large polypoid lesion protruding from the right nostril and producing asymmetry of the face. Diagnostic imaging illustrated a lesion of the right maxillary sinus producing excessive bone remodeling and extension into neighboring structures in every direction. Fine limits were noted, however, with no invasive characteristics. Biopsy under local anesthesia was performed, showing findings consistent with nonspecific inflammation. Open surgery through a lateral rhinotomy under general anesthesia was performed, and the mass was readily mobilized and removed. No macroscopic invasion of neighboring structures was noted. Permanent histology confirmed the diagnosis of nasal polyposis. Postoperative follow-up has shown no evidence of recurrence after 12 months.

Conclusion

Nasal polyps do not typically expand in an aggressive manner, producing bone resorption or extending into neighboring structures. However, nasal polyposis should be included in the differential diagnosis of nasal tumors with such behavior.