CT of Anatomic Variants of the Paranasal Sinuses and Nasal Cavity: Poor Correlation With Radiologically Significant Rhinosinusitis but Importance in Surgical Planning

Paranasal Sinus Hypoplasia and Sinonasal Anatomical Variants in Cystic Fibrosis Adult Patients: A Computed- Tomography-Based Volumetric Comparison with Healthy Controls

Objectives: In this retrospective study, we performed a volumetric analysis of paranasal cavity pneumatization in a population of adult patients with cystic fibrosis compared to healthy controls, providing parcel evaluation of each sinus, and analyzing the prevalence of major anatomical sinonasal variants in the two groups. Methods: We compared paranasal sinus volumes of 89 adult patients with cystic fibrosis and 144 healthy controls who underwent paranasal sinus computed tomography. Volumes were segmented and extracted on tomographic images using the freely available software MRIcron 2019, then compared using a t-test; the z-score test was used to determine whether the two groups differ significantly in terms of major anatomical variants prevalence. Results: Overall sinus volumes in patients with cystic fibrosis patients differ significantly as compared to the healthy population (p < 0.00001). Furthermore, with the only exception of ethmoid sinus pneumatization, which was similar in both populations, all the other sinuses were statistically different. No significant difference emerged concerning anatomical variants' prevalence. Conclusions: Our results further stress the impact of cystic fibrosis on sinus structure in adult patients, better revealing the consequences of the disease on upper airways and in optimizing the management of patients with sinonasal manifestations.

Functional Endoscopic Sinus Surgery: Key Points for Safer Surgery

Objectives: To review measures for safer functional endoscopic sinus surgery (FESS). Methods: PubMed, EBSCO, UpToDate, Proquest Central at Kırıkkale University, Google, and Google Scholar were used in the literature review. The search was performed using keywords of "functional endoscopic sinus surgery," "FESS," "Safety," "Image-Guided," and "complications" between 2000 and 2024. Results: Inflammatory and infectious sinus illnesses are the most prevalent indications for FESS. The 4 most common methods for FESS are endoscopic uncinectomy, maxillary antral ostomy/ethmoidectomy, anterior ethmoidectomy, and posterior ethmoidectomy. FESS has a complication rate of 0% to 1.5% for significant problems and 1.12% to 20.8% for minor issues. Sinus surgery outcomes can be improved and problems avoided with careful preoperative preparation. Powered instrumentation may enhance the severity of the problems rather than the number of occurrences. Intraoperative detection of cerebrospinal fluid leakage necessitates immediate localization and fixing of the leaking structure. The danger of infection increases and hospital stays are longer when investigation is delayed. In image-guided surgery, surgeons employ preoperative imaging data to pinpoint the exact position of a surgical tool concerning surrounding anatomical structures in real time. Although initially designed for use in neurosurgery, endoscopic sinus surgery has quickly become one of the most popular applications of this technique. Conclusion: Safer FESS can be accomplished with accurate CT scans, good patient preparation, surgical knowledge and training, and by using image guidance for endoscopic sinus surgery.

Evaluation of lamina papyracea dehiscence with paranasal computed tomography

INTRODUCTION

The lamina papyracea is the thin line between the ethmoid sinus and the medial orbital wall. Knowledge of the presence of the lamina papyracea dehiscence (LPD) bears critical importance to prevent misdiagnosis of fractures at this level and to define the anatomy before sinonasal surgery, including Functional Endoscopic Sinus Surgery (FESS). The present study is therefore intended to determine the incidence of LPD in paranasal computed tomography, to identify its imaging characteristics in CT, and to compare with the literature.

MATERIALS AND METHODS

The current study included patients who underwent paranasal CT scanning for any reason in our clinic between January 2018 and January 2022. Patients were evaluated in terms of age, gender, and presence of LPD. Patients with dehiscence were evaluated in terms of age, gender, dehiscence localization (right, left), tissue at the level of dehiscence, dehiscence size, and dehiscence grade.

RESULTS

1000 patients with a mean age of 32. ± 16.3 (min = 18-max = 79) were included in the study. 20 patients (2%) were found to have LPD. Of those with LPD, 14 (70%) were grade 1, 4 (20%) were grade 2 and 2 (10%) were grade 3. Again of those with LPD, 14 (70%) had LPD localized on the right and 6 (30%) had LPD on the left. In 12 (60%) of the patients with LPD, herniated tissue was detected. Among these patients with herniation, fatty tissue herniation was observed in 10 (83.3%) and medial rectus muscle herniation was observed in 2 (16.7%).

DISCUSSION AND CONCLUSION

Comprehensive evaluation for and identification of LPD are very important before possible sinus surgery.

Comparison of Low-Dose Non-contrast CT in Detecting Anatomical and Surgically Important Variants of Paranasal Sinuses to Standard Dose Non-contrast CT: Experience from a Tertiary Care Hospital in Sub-Himalayan Region of Northern India

Computed tomography (CT) is the gold standard for diagnosing sinusitis and anatomical variations and a guide for paranasal sinus (PNS) surgeries. High doses of radiation lead to increased risk of head and neck malignancies, radiation-induced cataracts, hypothyroidism, and hyperthyroidism. The purpose of this study was to assess the effectiveness of low-dose CT as compared to standard-dose CT in the identification of anatomical variants of paranasal sinus and rhinosinusitis. This was a prospective cross-sectional study consisting of 72 patients who were divided equally into cases (underwent low-dose CT for PNS) and controls (underwent CT for PNS using standard dose protocols). Prevalence of anatomical variants and sinusitis were compared. Image quality was assessed using volume CT dose index (CTDIvol), dose length product (DLP), scan length, and noise. Subjective assessment was done by two radiologists, and scores were given. The comparison and analysis of the quantitative and qualitative variables were done. Anatomical variants were comparable among cases and controls, with post-sellar sphenoid being most common and paradoxical middle turbinate being least common surgically important variant. The difference in mean SD of CTDIvol (mGy), DLP (mGy-cm), effective dose (mSv), globe, and air noise between low and standard doses was statistically significant. A moderate agreement (with kappa 0.50) in cases and substantial agreement (with kappa 0.69) in controls was observed between both observers. Low-dose CT PNS and standard-dose CT PNS are comparable in delineating the paranasal sinus anatomy, with a 3.53× reduction of effective radiation dose to patients.

Pneumatized Nasal Septum Extending to the Left Frontal Sinus "Septo-Frontal Cell": A Case Report

Multiple anatomical variations in the nasal cavity are well-described in the literature. We describe a rare case of pneumatization of the frontal sinus in the nasal septum that we term "Septo-Frontal Cell". To the best of our knowledge, this pattern of nasal septum pneumatization has not been described in the literature before. We have discussed the clinical and radiological findings and management of this patient.

Infectious and Inflammatory Sinonasal Diseases

Rhinosinusitis is a commonly encountered disease. Imaging is not typically required in acute uncomplicated rhinosinusitis; however, it is integral in the evaluation of patients who present with prolonged or atypical symptoms or when acute intracranial complications or alternate diagnoses are suspected. Knowledge of the paranasal sinus anatomy is important to understand patterns of sinonasal opacification. Bacterial, viral, and fungal pathogens are responsible culprits and, with duration of symptoms, serve to categorize infectious sinonasal disease. Several systemic inflammatory and vasculitic processes have a predilection for the sinonasal region. Imaging, along with laboratory and histopathologic analysis, assist in arriving at these diagnoses.

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.

Roles of Anatomical Abnormalities in Localized and Diffuse Chronic Rhinosinusitis

Background

This study aimed to examine the roles of anatomical variation in localized and diffuse chronic rhinosinusitis [LCRS and DCRS]) .

Methods

A database was analyzed retrospectively on patients hospitalized in the Department of Otorhinolaryngology of our university hospital from 2017 to 2020. A total of 281 patients were included and divided into three categories: patients with LCRS, patients with DCRS, and a normal control group. The frequency of anatomical variation, the demographic information, disease type (with or without polyps), symptom visual analogue scale (VAS) scores and Lund-Mackay (L-M) scores were calculated and compared.

Results

Anatomical variants were observed more frequently in LCRS than DCRS (P < 0.05). The frequency of variation was higher in the LCRSwNP group than the DCRSwNP group (P < 0.05), and higher in the LCRSsNP group than the DCRSsNP group (P < 0.05). The L-M scores for patients with DCRS with nasal polyps were significantly higher (14.96 ± 6.15) than those of patients with DCRS without nasal polyps (6.80 ± 5.00) and also significantly higher (3.78 ± 2.07) than those of patients with LCRS with nasal polyps (2.63 ± 1.12; P < 0.05). A poor correlation was observed between the severity of symptoms and the performance of CT scans in CRS (R = 0.29, P < 0.01).

Conclusion

Anatomical variants were common in CRS, and possibly correlated with LCRS but not with DCRS. The frequency of anatomical variation is not associated with the occurrence of polyps. CT could reflect the severity of disease symptoms to some extent.

The incidence of concha bullosa: a retrospective radiologic study

AIM

This study was conducted to discuss the incidence, directions, and types of concha bullosa using studies in the literature.

MATERIALS AND METHODS

The images of patients who presented to the ENT clinic with different ENT symptoms in the last 7 years and had paranasal sinus tomography were analyzed retrospectively.

RESULTS

The study consisted of a total of 3133 patients, including 1534 females (48.96%) and 1599 males (51.03%). The age range of the cases was between 12 and 85 years, and the mean age was 57.25 years. Middle concha bullosa was detected in 1402 (44.74%) of the cases. Of these cases, it was determined that 320 (22.82%) had right, 311 (22.18%) had left, and 771 (54.99%) had bilateral middle concha bullosa. Of middle types of concha bullosa, lamellar type concha bullosa was detected in 575 (41.01%) patients, bulbous type in 363 (25.89%), and extensive type in 464 (33.09%). Of the cases with lamellar type middle concha bullosa, it was found that 130 (22.60%) had right side, 105 (18.26%) had left side, and 340 (59.13%) had bilateral lamellar type middle concha bullosa. Of the cases that were determined to have bulbous type middle concha bullosa, 97 (26.72%) had right side, 99 (27.27%) had left side, and 167 (46.00%) had bilateral bulbous type middle concha bullosa. Of the cases that were determined to have extensive type middle concha bullosa, 93 (20.04%) had right side, 107 (23.06%) had left side, and 264 (56.89%) had bilateral extensive type middle concha bullosa. The incidence of superior concha bullosa was determined in 487 (15.54%) of 3133 cases. Of these, bilateral superior concha bullosa was detected in 332 (68.17%) cases and unilateral in 155 (31.82%) cases.

CONCLUSIONS

Our study has the largest case series among studies investigating the incidence of concha bullosa. The incidence of concha bullosa appears to be common in the community. Additional studies may be useful to determine whether its high incidence is associated with other sinus pathologies and the extent of its effect on other rhinological complaints.

Sinusitis and its association with deviated nasal septum at a tertiary hospital: A retrospective study

Objectives

Sinusitis is common and deviated nasal septum (DNS) is a frequent anatomical variant in the paranasal sinuses (PNS). Whether DNS can cause sinusitis has been a subject of debate. This study determined the rate of sinusitis and its possible association with DNS and other factors in patients attending King Abdulaziz University Hospital (KAUH).

Methods

We conducted a hospital-based cross-sectional study and reviewed the electronic health records of KAUH retrospectively. We recruited all patients aged ≥18 years who were referred to the Diagnostic Radiology Department for a PNS computed tomography scan from January 2018 to December 2020. Descriptive and inferential statistics were calculated.

Results

A total of 676 participants met the eligibility criteria, with a mean (SD) age of 38.9 (13) years. Sinusitis was present in 47.5% of patients, 54.8% ofwhich were males. Patients aged 31–40 years suffered sinusitis more than the other age groups.Approximately three-fourths (75.1%) of the total sample had DNS, and 51.3% of them had sinusitis. Those who did not have DNS but had sinusitis were 27.8%.There were significant associations between sinusitis and both sex (P <0.001) and age (P <0.05). Patients with DNS were approximately three times more likely to have sinusitis than those without DNS (OR =2.74, 95% CI:1.86–4.04; P <0.001).

Conclusion

Almost half of the patients had sinusitis, and three-fourths had DNS. Sex, age, and DNS are possible factors associated with sinusitis. Assessing the presence of DNS and correcting it, if possible, is recommended to prevent the occurrence of sinusitis.

Anatomy and Variations of Onodi Cells and Haller Cells: A HRCT Cum Clinical Analysis in Sinonasal Disease and Polyposis

The Onodi cell is defined as the posterior-most ethmoid cell. Haller cells are defined as infraorbital ethmoid cells. HRCT scanning provides excellent bone detail and accurate soft tissue mapping. The aim of this study is to know the prevalence of Haller cells and Onodi cells and to find variations in them on HRCT. Also to find co-relation between HRCT findings and Intra operative findings. A Hospital based prospective and cross-sectional study which included 30 patients above 15 years of age coming to ENT OPD with complaints related to sinonasal disease and polyposis;willing for HRCT followed by operative procedures. A total of 30 patients are included in the study. The mean age was found to be 38.70 ± 14.37. Prevalence of haller cells and onodi cells was 30% and 33.3% respectively. Statistical significance was found between association of haller cells with sinusitis. Intra-operative findings corresponded to 8 out of 9 HRCT findings (p-value = 0.001). We conclude that the actual prevalence of haller cell and onodi cell is best noted on HRCT-PNS and this holds a significant role in imparting thorough knowledge of the anatomical variations of PNS and hence preventing intraoperative complications due to presence of these variant cells.

[Endoscopic management and outcome of nasosinusitis in non-traumatic dehiscence of the lamina papyracea with orbital content herniation]

Objective:To analyze the CT manifestations, clinical features, and endoscopic management and outcome of nasosinusitis in non-traumatic dehiscence of the lamina papyracea with herniation of orbital contents. Methods:From January 2019 to October 2020, a total of 686 cases with chronic nasosinusitis or nasal septum deviation were admitted to our department, including 448 male cases and 238 female cases. No patient had prior maxillofacial or orbital trauma as well as surgery related to nose and eyes. The clinical data were retrospectively analyzed. Results:Twelve patients were diagnosed as dehiscence of the lamina papyracea. Preoperative CT revealed that the location of dehiscence was only in the ethmoid sinus. Conclusion:For nasosinusitis patients with non-traumatic dehiscence of the lamina papyracea, all ethmoid cells should be opened during FESS. Precise and skillful operation, good bleeding control and clear visual field were critical. no damage to the herniated periorbital fat during the operation and appropriate cavity packing after the operation are essential, which could avoid the orbital-related complications as well as improve the symptom resolution. No recurrence was found during the follow-up period.

ACR Appropriateness Criteria® Sinonasal Disease: 2021 Update

This article presents guidelines for initial imaging utilization in patients presenting with sinonasal disease, including acute rhinosinusitis without and with suspected orbital and intracranial complications, chronic rhinosinusitis, suspected invasive fungal sinusitis, suspected sinonasal mass, and suspected cerebrospinal fluid leak. CT and MRI are the primary imaging modalities used to evaluate patients with sinonasal disease. Given its detailed depiction of bony anatomy, CT can accurately demonstrate the presence of sinonasal disease, bony erosions, and anatomic variants, and is essential for surgical planning. Given its superior soft tissue contrast, MRI can accurately identify clinically suspected intracranial and intraorbital complications, delineate soft tissue extension of tumor and distinguish mass from obstructed secretions.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Anatomical Variations of the Sinonasal Area and their Clinical Impact on Sinus Pathology: A Systematic Review

Introduction  Anatomical variations of the nasal cavity and of the paranasal sinuses are frequently encountered and play an important role in dysfunctional drainage of sinuses. However, it is not clear in the literature whether they predispose to sinus pathology.

Objectives  The aim of the present review is to summarize the understanding of the association between anatomical variations of the sinonasal area and sinus pathology.

Data Synthesis  The present review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We performed a thorough research on PubMed from October 2004 until May 2020 by using the search terms paranasal sinus anatomical variations and sinus disease , sinusitis , and mucosal disease .

Thirty studies were eligible and were included in the analysis. Overall, the studies encompassed a total of 6,999 patients included in the present review. In many studies, it has been statistically established that certain anatomical variations increase the risk of sinus disease. On the other hand, the rest of the collected studies failed to show any statistically significant correlation between anatomical variants and sinus pathology.

Conclusion  The present study highlights the possible correlation between some anatomical variations of the sinonasal area and pathologies of the paranasal sinuses. Careful assessment and computed tomography (CT) in patients with chronic rhinosinusitis is needed, especially in those undergoing endoscopic surgery, to identify and treat anatomical variations in the paranasal sinuses that may be correlated with rhinosinusitis. Due to contradictory results in the literature, further research is needed to elucidate the effects of anatomical variants of the sinonasal area.

Correlation Between Anatomic Variations of Sphenoid Sinuses and Pituitary Adenoma

BACKGROUND

Many persons have studied relationship between anatomic variations (AVs) of sphenoid sinuses (SS) and paranasal disease, but no research has been done to reveal the correlation between AVs of SS and sellar region lesions.

OBJECTIVE

To compare AVs of SS between sellar region lesions and healthy persons and analyze factors affecting the volume of SS and explore the correlation between AVs of SS and pituitary adenomas (PAs).

METHODS

Clinical data of 53 PAs as experiment group and 30 healthy persons as control team was reviewed. Computed tomography images of SS performed at Tianjin Huanhu Hospital were studied. The AVs of SS including degree of pneumatization, type of intersinus septum (IS), and volume of SS were evaluated by ITK-SNAP software.

RESULTS

Age, gender, degree of pneumatization, and type of IS had no significant difference between groups, while the volume of SS in experiment group was smaller than that in control group (P < 0.05). The volume of SS was associated with age, sex, degree of pneumatization, type of IS in control group, and degree of pneumatization, type of IS in experiment group. In experiment group, patients with postoperative pathological examination ki67 ≥ 3% had bigger volume and higher recurrent rate (P < 0.05).

CONCLUSION

Visualizing different orientations and 3D model of SS is conducive to the success of trans-sphenoid surgery. Pituitary adenomas can deform the SS leading to smaller volume. The volume of SS can be a factor used to predict the outcome of PAs.

Cone-Beam Computed Tomography: A User-Friendly, Practical Roadmap to the Planning and Execution of Every Rhinoplasty-A 5-Year Review

BACKGROUND

Cone-beam computed tomography has recently rapidly developed worldwide as a versatile and convenient alternative to traditional computed tomography for imaging of the maxillofacial region. However, most surgeons performing rhinoplasty are surprisingly unfamiliar with it, in both the plastic surgery and ear, nose, and throat communities.

METHODS

The broad clinical experience of a single center over the past 5 years is reviewed. The many applications of cone-beam computed tomography to primary and secondary rhinoplasty are analyzed regarding septum, turbinates, nasal bones, skin thickness, and other issues. The importance of a paradigm shift from a two-dimensional to a three-dimensional approach in image reconstruction is demonstrated, together with the value of surface contour enhancement.

RESULTS

Cone-beam computed tomography has a multitude of practical applications highly relevant to rhinoplasty. The surface image will strengthen aesthetic analysis, and the detailed preview of bony and functional anatomy will facilitate surgical planning. Cone-beam computed tomography serves as a roadmap to plan and execute rhinoplasties more predictably and efficiently. The availability of spatial views and accurate detail, together with the possibility of easy, accurate measuring, offers a plenitude of potential applications.

CONCLUSIONS

Cone-beam computed tomography is a user-friendly, quick technique with abundant advantages in planning any rhinoplasty. It causes the patient no inconvenience and has very few, if any, drawbacks, with these being limited to radiation exposure and limited cost.

The Role of Imaging in the Preoperative Assessment of Patients with Nasal Obstruction and Septal Deviation-A Retrospective Cohort Study

Introduction  Isolated nasal obstruction (INO) is a common complaint of multiple etiology. The preoperative evaluation of patients presenting with nasal obstruction and deviated nasal septum (DNS) does not typically include imaging. The benefits of performing computed tomography (CT) in the preoperative setting are inconclusive. Objective  Assessing the contribution of preoperative CT to the surgical treatment of non-sinusitis patients presenting with INO and DNS. Methods  A retrospective cohort study on patients referred to surgery for nasal obstruction due to DNS or turbinate hypertrophy between 2006 and 2015. Data was retrieved from patients' medical charts. The CT scans and clinical data were reassessed by a second surgeon blinded to the patients' clinical course. Results  Seventy of the 843 patients (8.06%) who underwent endoscopic sinonasal procedures during the study period had presented with INO and met the inclusion criteria. Thirty-eight (55.88%) of them underwent CT scans during their preoperative assessment. Modification of the initial preoperative planning based on the radiological findings was required in 32 cases (84.2%). When reassessed by a second blinded surgeon, 58% of cases required surgical modification rather than classical submucosal resection of nasal septum and turbinate reduction ( P  = 0.048). Conclusion  Computed tomography was found beneficial in the preoperative planning for patients with INO. The original surgical plan based upon physical examination findings was modified based on radiological findings in 84.2% of the patients.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Prevalence of maxillary sinus hypoplasia and association with variations in the sinonasal complex: a cone beam CT study

OBJECTIVE

Understanding of maxillary sinus hypoplasia (MSH) and associated sinonasal variants is paramount to the diagnostic and therapeutic success of maxillary sinus and maxillary dental implant surgery. The purpose of this work was to explore the prevalence of MSH, frequency of mucosal thickening, and anatomical variations in the sinonasal complex.

METHODS

Retrospective case-control design based on cone beam CT images of dental patients with MSH and matched for age and gender. MSH type and sinonasal variables were recorded.

RESULTS

One thousand three hundred seventy cone beam CT scans were analyzed for MSH. MSH prevalence was 6% (n=82), matched with 82 controls= 100 females and 64 males, mean age 37.1±14.1 years. Most MSH were type I, 69.5%, 80.5% unilateral, 65.9% associated with no or mild mucosal thickening. Associated sinonasal anatomical variations were <27% except for deviated/hyperplastic (DH) meatus, 48.8%. Within the MSH group, significant associations were presented between MSH type, mucosal thickening, and DH nasal meatus. MSH group vs controls showed a significant difference in mucosal thickening (OR 5.2, 95% CI 2.0-17.3) and DH meatus (OR 1.6, 95% CI 1.4-2.1).

CONCLUSIONS

A hypoplastic maxillary sinus with abnormal or absent uncinate process is associated with advanced mucosal thickening and may present with altered anatomy of the lateral wall of the nasal cavity causing its approximation to the orbital floor.

CLINICAL RELEVANCE

Pre-surgical knowledge of altered anatomy in the sinonasal complex is crucial in dental implant or sinus surgery.

Anatomical Variations of the Nasal Cavities and Paranasal Sinuses: A Systematic Review

The anatomy of the nasal cavities and paranasal sinuses is one of the most varied in the human body. The aim of this study is to review the prevalence of anatomical variations in the sinonasal area. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We performed on PubMed a literature search from October 2004 until May 2020. The search strategy included the following keywords: ('paranasal sinus' OR 'frontal sinus' OR 'maxillary sinus' AND ('anatomical variants' OR 'anomalies')). Fifty studies were eligible and included in the analysis. Overall, the studies encompassed a total of 18,118 patients included in this review. Most common anatomical variations include agger nasi cells, nasal septum deviation and concha bullosa. Other variations seen in this region are uncinate process variations, paradoxical middle turbinate, Haller, Onodi and supraorbital ethmoid cells, accessory ostia of maxillary sinus. Less common variations include any sinus aplasia, crista galli pneumatization and dehiscence of the optic or maxillary nerve, internal carotid artery and lamina papyracea. Anatomical variations of this region also differ among ethnic groups. This study highlights the amount, variability and significance of most anatomical variants reported in the literature in the last years. It is essential for the sinus surgeon to have a broad spectrum of knowledge not only of "the typical" anatomy but also all the possible anatomical variations. With modern imaging modalities, anatomical variations can be detected, and uneventful pitfalls might be prevented.

A CT-Scan review of anatomical variants of sinonasal region and its correlation with symptoms of sinusitis (nasal obstruction, facial pain and rhinorrhea)

Objective:

To determine the incidence of anatomical variants of sinonasal region and its correlation with symptoms of sinusitis.

Methods:

The study was conducted from January-June 2020 at Radiology Department of PNS Shifa Hospital, Karachi. The study involved 50 symptomatic subjects of sinusitis with age ranges from 18-60 years which were prepared for computed tomography of paranasal sinuses. The scans were reviewed for nasal-septum, turbinates, uncinate process, ethmoid air-cells along with other anatomical variants and were correlated with symptoms of sinusitis.

Results:

Out of 50 subjects, 34 were males and 16 were females with mean age of 42.68±18.22 years. Most common anatomical variants observed were agger nasi cells (64%), deviated nasal septum (56%), and concha-bullosa (46%). Statistically significant correlation existed between bilateral agger nasi cells and nasal obstruction (p=0.017, ρ= -0.336).

Conclusion:

The anatomy of sinonasal region is highly complex. However, anatomical variants can disturb the sinus mucociliary drainage pathway resulting in patient suffering. Therefore, considering the variable anatomy of sinonasal region, CT-PNS is recommended for every subject in order to avoid surgical hazards.

Anatomographic Variants of Sphenoid Sinus in Ethiopian Population

Neurosurgeons often neglect the sphenoid sinus due to its deep location and difficulties in accessing during surgical interventions. Disease of the sphenoid sinus is difficult to diagnose since its presenting symptoms are difficult to recognize. Moreover, compared with other paranasal sinuses, the sphenoid sinus is considered the most variable air sinus in terms of its degree of pneumatization, number and position of inter-sinus septa, and its relationship with the surrounding anatomical structures. Anatomical variations of the sphenoid sinus are significant from a neurosurgical point of view. Understanding of these variations and its relationships with surrounding structures such as the internal carotid artery, optic nerve, and pituitary gland are clinically relevant to minimize injuries associated with surgical procedures that involve sphenoid sinus. We implemented principles of imaging using computed tomography to elucidate any anatomical variations of the sphenoid sinus in the Ethiopian population. We conducted a prospective study in 200 patients with ages 18-79, who underwent scans of the sphenoid sinus at the Tikur Anbessa Referral Teaching Hospital in 2017-2018. Our findings revealed an incidence of anatomographical variations in terms of pneumatization that varied between 2-50%. These variants include 2% conchal, 25.5% presellar, 50% sellar, and 22.5% postsellar pneumatization. We also demonstrated anatomographic variants in terms of septation, 77.5% single complete septa, 11.5% single incomplete, 10% double septa, and 1% absence of septa. In summary, the sellar pneumatization was found to be the most clinically relevant anatomographic variant among Ethiopians participating in the study, of which 90% were tomographically single septated. These variants must be taken into consideration during trans-sphenoidal surgery and knowledge of the variations has clinical implication in minimizing injuries during invasive surgical procedures involving the sphenoid sinus.

The Relationship Between Nasal Septal Deviation and Paranasal Pneumatization

OBJECTIVE

To investigate the impact of the presence and the severity of the nasal septal deviation (NSD) on the paranasal pneumatization.

METHODS

Initially, the deviated and contralateral sides was compared to evaluate the impact of the presence of NSD on pneumatization. Then, NSD classification groups were categorized according to the severity of deviation degree; 1: mild (<9°), 2: moderate (9°-15°), and 3: severe (>15°). Pneumatization of all paranasal sinuses, osteomeatal complex (OMC), frontoethmoid recess (FER) and variant structures were compared according to the NSD classification groups separately both for the deviated and the contralateral sides.

RESULTS

Although there was no statistically significant difference in pneumatization of the paranasal sinuses between the deviated and contralateral sides, a significant difference was observed in OMC and FER diameters. In the deviated side, there was statistically significant difference in ethmoid sinus volume, in FER and OMC diameters between NSD classification groups. In the contralateral side, FER and OMC diameters were found to be significantly different between group 1 and group 2 and between group 1 and group 3, respectively (P = 0.04 and 0.06, respectively). Both the presence and severity of the NSD did not statistically significant influence the pneumatization of variant structures, air cells and vital structures.

CONCLUSION

The severity of NSD effects the ethmoid sinus volume. The relationship of FER and OMC with NSD is evident, however this may not always be in a proportional pattern. The paranasal pneumatization did not affect Keros type, bone integrity of carotid canal and optic canal.

Identification of Significant Anatomical Variations in the Nose and Anterior Skull Base Using Computed Tomography: A Cross-Sectional Study

Introduction This study is aimed at the identification of anatomic variations in the nose, paranasal sinuses (PNS), and anterior skull base, which are substantially important to ensure safe and complete endoscopic sinus and skull base surgery. Materials and methods This cross-sectional study was conducted at the Dow Institute of Radiology, Dow International Medical College, Dow University Hospital. We included adult patients (i.e., those aged 18 years or older) undergoing a non-contrast CT of the nose and PNS. Two consultant radiologists reviewed the scans on the picture archiving and communication system independently. Any conflict was resolved with consensus. Anatomical variations in the nose, PNS, and anterior skull base of both sides were evaluated. Results We reviewed the CT of the PNS of 130 patients with an age of 35.8 ± 14.48 years (mean ± standard deviation). The proportion of men (64/130; 49.2%) and women (66/130; 50.8%) was equal. All patients had one or more variations. The most common abnormality was a deviated nasal septum (DNS), observed in 115 of 130 participants (88.5%) with unilateral occurrence predominant. It was followed by inferior nasal turbinate hypertrophy and agger nasi cells in 76.2% and 67.7% patients, respectively. Optic nerve variation type I (160/260 sinuses; 61.5%) and Keros type II, for olfactory depth (162/260 sinuses; 62.3%), were most common. Conclusions Here we report anatomical variations in PNS in all patients of our study; the commonest of all anatomical variations was a DNS. A CT scan is instrumental in surgical planning and patient safety in functional endoscopic sinus surgery.

Nasal cavities and the nasal septum: Anatomical variants and assessment of features with computed tomography

The nasal cavities are complex anatomical structures with high inter-individual variability that relates to different functions. Different anatomic variants may manifest at this site, mainly belonging to the nasal septum and turbinates. Precise knowledge of the anatomy and variants is fundamental for both radiologists and ENT surgeons. This article provides an overview of the main anatomic variants and their frequency, according to the existing literature, as well as ongoing research on nasal cavity segmentation in order to obtain personal 3D models and to predict post-surgical results.

Anatomic Variations of Paranasal Region in Migraine

PURPOSE

To assess the incidence of anatomical variations of the paranasal region on computed tomography in migraine patients compared with control subjects.

METHODS

Paranasal computed tomography scans of 2 groups consisting of 50 migraine patients and 50 control subjects were evaluated, retrospectively. The presence of anatomic variations and the unilateral or bilateral presence of these variations were noted. Appropriate statistical tests were performed to compare the migraine and control groups, using a threshold P value of 0.05 for statistical significance.

RESULTS

The migraine group included 39 female and 11 male patients with mean age of 39.9 (range: 18-65) years. The control subject group included 29 female and 21 male patients with mean age of 41.9 (range: 18-73) years. Anatomic variations noted included nasal septal deviation and spur, paradoxical curvature of middle concha, agger nasi cell, infraorbital ethmoidal (Haller) cells, sphenoethmoidal (Onodi) cells, supraorbital ethmoidal air cells, concha bullosa, uncinate bulla, and pneumatized crista galli. Of these variations, only the presence of Haller cells was statistically significantly higher in the migraine group compared with controls (P = 0.007). The unilateral presence of Onodi (P < 0.001), unilateral presence of supraorbital ethmoidal air cells (P = 0.012), and bilateral presence of concha bullosa (P = 0.016) were statistically significantly higher in the migraine group. There was no statistically significant difference between the unilateral or bilateral presence of Haller cells in migraine patients compared with controls (P > 0.05).

CONCLUSION

Radiographic assessment of the paranasal sinuses is useful to elucidate potential points of pathology in migraine patients. The specific contribution of Haller cells to migraine headache symptoms and safe methods for surgical decompression warrant further study.

Prolapse of Orbital Fat through the Inferior Orbital Fissure: Description, Prevalence, and Assessment of Possible Pathologic Associations

BACKGROUND AND PURPOSE

A few patterns of orbital fat prolapse have been described. Some are associated with disease, and others may mimic a neoplasm. We have observed prolapse of orbital fat into the infratemporal fossa via the inferior orbital fissure on MR imaging. The clinical relevance of this finding, if any, is unknown. The purposes of this study were to describe the MR imaging appearance of orbital fat prolapse through the inferior orbital fissure, to estimate the prevalence of this finding, and to assess possible pathologic associations.

MATERIALS AND METHODS

For this retrospective study of 228 orbital MR imaging examinations, 3 neuroradiologists independently assessed the presence of prolapse on high-resolution T1-weighted images. Discrepancies were resolved by consensus, and interobserver agreement was calculated. Patient demographics, indications for imaging, and pertinent clinical history were recorded. One-way analysis of variance and the Fisher exact test were used to assess possible associations between prolapse and specific patient characteristics.

RESULTS

Orbital fat prolapse through the inferior orbital fissure was observed in 20/228 patients (9%). This finding was unilateral in 11 patients (55%) and bilateral in 9 patients (45%). There was no significant association with age, sex, obesity, Graves disease, hypercortisolism, prior orbital trauma, proptosis, or enophthalmos. Interobserver agreement was 90%.

CONCLUSIONS

Prolapse of orbital fat into the infratemporal fossa via the inferior orbital fissure is a relatively common finding on orbital MR imaging that has no identified pathologic association. Neuroradiologists should recognize this finding so as not to report it as pathologic.

Can Volumetric and Morphological Variants of Sphenoid Sinuses Influence Sinuses Opacification?

Improvements in computed tomography and in functional endoscopic sinus surgery have recently increased interest toward paranasal sinus anatomy and anatomic variations that can be observed in patients affected by sinusitis. Isolated sphenoid sinusitis is a relatively rare pathology, often related to nonspecific symptoms, therefore making diagnosis difficult. The correlation between this type of sinusitis and anatomical variants remains unclear.The authors' aim was to retrospectively revise paranasal sinuses computed tomography scans of patients affected by sphenoid sinusitis, compared with a control group, analyzing the types of sphenoid sinus and the presence of aberrant pneumatization, and performing a segmentation of the sphenoid sinuses to calculate the volumes.Sphenoid sinuses of 60 patients affected by sinus opacification, compared with a control group, were segmented. Type of sinus (sellar, presellar, postsellar) and presence of aberrant pneumatization were assessed as well. Possible statistically significant differences in volumes according to sex and group were assessed through 2-way ANOVA test (P < 0.05). Post-hoc test was assessed through Student t test. χ test was applied in order to verify the statistically significance of differences in frequency of different types of sinus pneumatization variants (P < 0.05).Average volume of sphenoid sinuses in males was of 7.672 cm and of 7.751 cm in females within the group of patients; statistically significant differences in volume were found according to sex (P: 0.342), but not between the patients and control group (P: 0.0929). Post-hoc test verified that males affected by sinus opacification showed smaller volumes in comparison with the control males (P < 0.05). In addition, patients by affected sinus opacification showed more frequently the postsellar type and were less affected by pneumatization variants of the sphenoid bone than the control group (P < 0.05).This study first suggests the possible protective role of variants of pneumatization in the development of sphenoid sinus opacification.

Evaluation of superior concha bullosa by computed tomography

OBJECTIVE

Concha bullosa is generally regarded as pneumatisation of the middle turbinate in the nose. However, pneumatisation may also be seen in the superior and inferior turbinate. Computed tomography (CT) of paranasal sinuses is extremely helpful for the examination of this inaccessible area. Coronal CT sections of paranasal sinuses are particularly useful for surgical anatomy, as these images show nearly the same regions as the endoscopic examinations. The aim of this retrospective study was to evaluate the presence, incidence and unilaterality-bilaterality of superior turbinate pneumatisation and concomitant nasal pathologies.

METHODS

A total of 1000 patients who underwent CT of the paranasal sinuses because of headaches, nasal obstructions, anosmia, facial pain or facial trauma were evaluated retrospectively.

RESULTS

Among the 1000 patients, superior pneumatized turbinate was seen on CT images of the paranasal sinuses in 149 (14.9%) cases. Of these patients, 84 were female, 65 were male, and the mean age was 38.14 years. Among 149 patients, 58 patients had bilateral superior pneumatized turbinate and the remaining 91 patients had unilateral superior pneumatized turbinate. 60.4% of the patients with superior pneumatized turbinate also had middle pneumatized turbinate.

CONCLUSION

The superior pneumatized turbinate is an anatomical variation with an incidence ranging from 12.2 to 50%. The present study revealed that there is no relationship between volume size of the superior pneumatized turbinates and sinusitis, nasal septum deviation and paradoxical middle concha. It is very important to define anatomical variations in the preoperative CT evaluation of the paranasal sinuses.

Diagnostic Performance of Multidetector Computed Tomography (MDCT) in Diagnosis of Sinus Variations

Background

In this prospective study, we looked for correlations between anatomic variants of paranasal sinuses and chronic or recurrent sinusitis.

Material/Methods

Two hundred and forty (240) patients with clinical features of chronic rhinosinusitis were examined; patients with first-onset or allergic sinusitis and pregnant females were excluded. Routine multi-slice CT of the paranasal sinuses was performed to look for mucosal disease of the paranasal sinuses, drainage pathways, and presence of anatomical variations and their relation to known sinus drainage pathways.

Results

Anatomic variations were very frequent, and we classified them into four easily recognized groups: nasal septum variations, middle turbinate variations, uncinate process variations, and ethmoidal variations. Deviated nasal septum was the most frequent variation in patients with chronic or recurrent sinusitis, and it was detected in 48.8% of cases. Agger nasi cells and concha bullosa were equally frequent (30.6%), and Haller cells were detected in 11.2%. Uncinate process variations were detected in 18.1%, and the large ethmoid bulla was detected in 10%.

Conclusions

The importance of anatomic variations is that they can compromise drainage pathway of the related sinus, which results in inflammatory sinus disease. Anatomical variations are not diseases on their own and may be present as incidental findings in patient with chronic sinusitis.

Role of Sinonasal Anatomic Variations in the Development of Maxillary Sinusitis: A Cone Beam CT Analysis

Background:

Several anatomical variations can lead to the inflammation of the paranasal sinuses; therefore, surgeons should be familiar with these variations and their impacts on the status of the paranasal sinuses.

Objectives:

The present study aimed to determine the prevalence of Haller cells and its association with patients’ sex and age. Furthermore, the relationships between the presence and size of Haller cells, deviation of the uncinate process and size of the maxillary sinus ostium with the occurrence of maxillary sinusitis were investigated.

Materials/ Patients and Methods:

120 coronal CBCT images were retrieved and analyzed. Statistical analysis of the data was performed by means of Mann - Whitney, χ² and T tests.

Results:

There were statistically significant associations between the presence and surface area of Haller cells and the occurrence of ipsilateral maxillary sinusitis. Neither the angulation of the uncinate process nor the size of the maxillary sinus ostium significantly correlates with the formation of maxillary sinusitis.

Conclusion:

Haller cells can interfere with the normal drainage of the maxillary sinus and result in sinusitis. In contrast, diameter of the sinus ostium and deviation of the uncinate process do not influence the inflammatory status of the maxillary sinus significantly.

The incidence of concha bullosa, unusual anatomic variation and its relationship to nasal septal deviation: A retrospective radiologic study

OBJECTIVE

Identifying anatomical variations associated with pathological findings is very useful for diagnoses and therapeutics. We conducted a study to detect various anatomical variations (superior, middle, inferior turbinate concha bullosa, uncinate bulla and nasal swell body [NSB]) in connection with nasal septal deviation.

METHODS

This study used a retrospective radiological design to analyze 594 (1188 sides) osteomeatal computed tomography scans from 494 male patients and 100 female patients aged between 17 and 75 years. We randomly selected 100 male and 100 female patients as controls; we compared the groups and performed a statistical analysis. All patients in the control group had sinusitis only (i.e., they lacked nasal septal deviations).

RESULTS

Left-sided septal deviation was found to be slightly more prevalent than right-sided deviation (43.9% and 36.4%, respectively). The incidence of S-curved septal deviation was 18.5%, that of dorso-ventral deviation was 10.9%, and that of caudal-rostral deviation was 7.6%. The incidence of only septal spur was 1.2%. In the case of middle turbinate concha bullosa, the incidence of the unilateral type was 17.3% and that of the bilateral type was 36.4%. In superior turbinate concha bullosa, the incidence of the unilateral type was 11.3% and that of the bilateral type was 27.4%. The incidence of inferior turbinate concha bullosa was 1.0% and that of uncinate bulla was 1.7%. NSB was found in 25.1% of patients, 24.7% of males and 27.0% of females. The frequencies of middle and superior concha bullosa were about 10-12 fold higher on the concave side. The nasal septal deviation group exhibited a higher incidence of most anatomical variants than the non-deviated group; differences in the middle turbinate concha bullosa attained statistical significance.

CONCLUSION

The radiologist must focus on anatomical variants in the preoperative evaluation. It is important for surgeons to be aware of these variations.

Reduction of Radiation Dosage in Visualization of Paranasal Sinuses in Daily Routine

Background. Preoperative imaging of the nose and paranasal sinus is standard in otorhinolaryngology. Previous studies on phantoms demonstrated the potential for dose reduction of cone beam computed tomography (CBCT) by varying the application parameters. Methodology. Based on previous studies, the standard protocol of paranasal sinus imaging by CBCT was altered. One hundred and fifty examinations using the old protocol (01/2010–01/2011, high dosage) and 150 examinations using the new protocol (09/2012–09/2013, low dosage) were evaluated and compared for the visibility of 17 anatomical structures, the Lund-Mackay Score, and technical parameters. Results. Alteration of the protocol resulted in a significant reduction in dosage (6.64 mGy versus 2.88 mGy). Both groups showed the same amount of pathology (Lund-Mackay Score: 4.95 ± 3.79 versus 5.26 ± 5.77; p = 0.558). There was a significant better visibility of the anatomical structures (all visible = 1, nothing visible = 4) (results: 1.25 versus 1.17; p = 0.001) in the low-dosage group. Conclusion. Despite a significant reduction in the applied dosage, reliable visualization of the bony anatomy of the anterior skull base is possible by CBCT. This demonstrates the need for the discussion of the required clinical imaging quality.

Imaging of Paranasal Sinuses and Anterior Skull Base and Relevant Anatomic Variations

This article reviews the normal anatomy and variants of the anterior skull base and sinonasal cavities that are relevant to endoscopic sinus and skull base surgery. Radiologists should be aware of sinonasal anatomy that can be impediments to surgical access and increase risk of vascular or cranial nerve injury during surgery. Imaging features of the paranasal sinuses and anterior skull base pathologies are also discussed.

Anatomic variants of the paranasal sinuses in patients with recurrent acute rhinosinusitis

BACKGROUND

The incidence and potential disease impact of paranasal sinus anatomic variants in patients with recurrent acute rhinosinusitis (RARS) has important implications for management, including surgery, but is incompletely defined.

METHODS

A retrospective review of 26 patients with RARS who had undergone computed tomography (CT) was performed. Patient demographics, RARS severity and comorbidities were reviewed. CT scans were reviewed for the incidence of anatomic variants in all patients. The pattern of inflammatory changes was explored in the subset of patients with acute rhinosinusitis at the time of CT. Potential correlation between the presence of anatomic variants and disease severity were investigated.

RESULTS

In the patient cohort who met inclusion criteria, the most common variants included agger nasi cell (88.5%), concha bullosa (53.8%), infraorbital cell (50%), and deviated nasal septum with middle meatus obstruction (42%). In exploring correlations with RARS severity, type 2 frontal cells correlated with a greater number of years with RARS (0.0363). In the 23 patients who underwent CT at the time of an acute infection, no statistically significant correlation was found between severity or location of inflammatory changes and the presence of anatomic variants.

CONCLUSION

This study describes the incidence of anatomic variants in a cohort of patients with RARS. A correlation between the presence of anatomic variants and the pattern of inflammatory changes was not identified.