Imaging of the paranasal sinuses

Diagnosis of Odontogenic Maxillary Sinusitis by Cone-beam Computed Tomography: A Critical Review

INTRODUCTION

This review aims to provide an up-to-date overview of the current applications of cone-beam computed tomography (CBCT) and other imaging modalities in diagnosing odontogenic maxillary sinusitis (OMS). Furthermore, the clinical operation procedures of radiography modalities in OMS diagnosis were summarized, with the goal of assisting clinicians in improving OMS diagnostic accuracy in clinical practice.

METHOD

A comprehensive review of researches that discussed the applications of radiography modalities in the diagnosis of OMS was conducted. Pertinent information was evaluated and organized for this review.

RESULTS

Cone-beam computed tomography (CBCT) offers a superior, high-resolution, and three-dimensional view of the maxillary tooth-bone-sinus complex compared to conventional radiography modalities. It enables a better understanding and classification of the spatial relationships between root apices/periapical lesions and maxillary sinus. The use of CBCT, combined with the advantages of other radiography modalities and proper image interpretation, is indispensable to enhance OMS diagnostic accuracy and mitigate the risk of missed or misdiagnosis.

CONCLUSION

The significance of CBCT in the diagnosis of oral and maxillofacial conditions has garnered widespread recognition. It provides highly precise diagnostic information and classification basis for OMS. The clinical operation procedures for imaging examination are essential in ensuring the consistency and reliability of the diagnosis.

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.

Analyzing the maxillary sinuses using 3D-modeling

Introduction. The study of the anatomy of the maxillary sinuses using computed tomography (CT) techniques is an important area of scientific research. The most developing technique that allows you to move from planar images to a picture that clearly represents the shape of the anatomical structure and topographic-anatomical relationships is 3D-modeling.

Purpose. Analyze the forms of the maxillary sinuses using 3D-modeling using the Autoplan APK.

Materials and methods. The primary analysis included 260 studies, from which 80 studies were subsequently selected. The studies were carried out on Aqulion 32 (Toshiba, Japan) and Revolution EVO 128 (GE, Russia) computed tomographs. MSCT was performed on patients aged 22 to 84 years. The average age of patients in the study group was 52.31±3.18 years. To stratify the patients of the study group by age groups, the age periodization scheme of the Institute of Age Physiology of the Russian Academy of Medical Sciences (1969) was used.

Results. The analysis of the shape of the maxillary sinuses showed that the trends in the prevalence of different types of their forms are almost the same, both in the general analysis of the shape of the maxillary sinuses in the study group, and in the isolated analysis of the right and left maxillary sinuses.

Conclusion. To conduct a full study of the shape of the maxillary sinuses allows only their three-dimensional modeling, it also allows you to move from linear dimensions to volumetric measurements by highlighting all the elements of the volumetric image that relate to the sinus cavity. The study of the shape of the maxillary sinuses is a modern problem with the lack of a unified approach to the process of segmentality and interpretation of the results. With regard to otorhinolaryngology, three-dimensional reconstructions of images semi-accepted on the basis of computed tomography are effective in assessing the choice of the type of surgery that is most acceptable in a particular patient.

Guidelines for magnetic resonance imaging in pediatric head and neck pathologies: a multicentre international consensus paper

The use of standardized imaging protocols is paramount in order to facilitate comparable, reproducible images and, consequently, to optimize patient care. Standardized MR protocols are lacking when studying head and neck pathologies in the pediatric population. We propose an international, multicenter consensus paper focused on providing the best combination of acquisition time/technical requirements and image quality. Distinct protocols for different regions of the head and neck and, in some cases, for specific pathologies or clinical indications are recommended. This white paper is endorsed by several international scientific societies and it is the result of discussion, in consensus, among experts in pediatric head and neck imaging.

Correlation between magnetic resonance imaging and cone-beam computed tomography for maxillary sinus graft assessment

Purpose

Little is known regarding the accuracy of clinical magnetic resonance imaging (MRI) protocols with acceptable scan times in sinus graft assessment. The aim of this study was to evaluate the correlations between MRI and cone-beam computed tomographic (CBCT) measurements of maxillary sinus grafts using 2 different clinical MRI imaging protocols.

Materials and Methods

A total of 15 patients who underwent unilateral sinus lift surgery with biphasic calcium phosphate were included in this study. CBCT, T1-weighted MRI, and T2-weighted MRI scans were taken 6 months after sinus lift surgery. Linear measurements of the maximum height and buccolingual width in coronal images, as well as the maximum anteroposterior depth in sagittal images, were performed by 2 trained observers using CBCT and MRI Digital Imaging and Communication in Medicine files. Microcomputed tomography (micro-CT) was also performed to confirm the presence of bone tissue in the grafted area. Correlations between MRI and CBCT measurements were assessed with the Pearson test.

Results

Significant correlations between CBCT and MRI were found for sinus graft height (T1-weighted, r=0.711 and P<0.05; T2-weighted, r=0.713 and P<0.05), buccolingual width (T1-weighted, r=0.892 and P<0.05; T2-weighted, r=0.956 and P<0.05), and anteroposterior depth (T1-weighted, r=0.731 and P<0.05; T2-weighted, r=0.873 and P<0.05). The presence of bone tissue in the grafted areas was confirmed via micro-CT.

Conclusion

Both MRI pulse sequences tested can be used for sinus graft measurements, as strong correlations with CBCT were found. However, correlations between T2-weighted MRI and CBCT were slightly higher than those between T1-weighted MRI and CBCT.

Headache Caused by Sinus Disease

Headaches and sinus disease are common reasons to seek medical care, with marked worldwide prevalence and large socioeconomic burdens. Headaches caused by sinus diseases are rare; many "rhinogenic headaches" are actually migraines. The similar symptoms may result from autonomic dysfunction and trigeminovascular pathways. Using the mnemonic ACHE, this article presents key Anatomy, Clinical cases, How to image, Essential clinical and radiographic features that help the radiologist, otolaryngologist, and neurologist evaluate sinus disease and headaches.

The value of the apparent diffusion coefficient calculated from diffusion-weighted magnetic resonance imaging scans in the differentiation of maxillary sinus inflammatory diseases

OBJECTIVES

This study examined the value of the apparent diffusion coefficient (ADC) calculated by using diffusion-weighted imaging (DWI) in the differentiation of inflammatory lesions of the maxillary sinus.

STUDY DESIGN

Sixty-five maxillary sinus magnetic resonance imaging (MRI) scans with findings suggestive of inflammatory lesions were qualitatively categorized into 4 distinct groups by using T2-weighted images: group 1: presence of mucosal thickening; group 2: presence of sinonasal polyps or mucous retention cysts; group 3: presence of fluid identified by air-fluid levels with a homogeneous signal intensity; and group 4: presence of fluid identified by air-fluid levels with a heterogeneous signal intensity. The ADC of each imaging finding was measured by using a 5-mm area of interest. Statistical differences between the groups were determined by using nonparametric tests with a 5% significance level.

RESULTS

Statistically significant differences were observed between group 1 and the other groups. Mucosal thickening was associated with lower ADC values compared with the other inflammatory lesions.

CONCLUSIONS

The ADC can be useful in differentiating mucosal thickening from other inflammatory alterations in the maxillary sinuses. Mucosal thickening had more restricted water diffusion compared with the other inflammatory lesions.

Diffusion-weighted magnetic resonance imaging of the paranasal sinuses: A systematic review

OBJECTIVES

This was a systematic review of studies on the use of diffusion-weighted imaging (DWI) for paranasal sinus diseases. The applications of DWI were analyzed along with the main results, and conclusions were obtained by the investigators.

STUDY DESIGN

Databases were searched using the keyword "diffusion" combined with "sinonasal," "paranasal sinus," "maxillary sinus," "frontal sinus," "ethmoid sinus," and "sphenoid sinus," including only articles that were published from 2008 to 2018. Only original English language studies with sinonasal disease samples were selected.

RESULTS

Sixteen studies about various sinonasal diseases were included. The main objectives of most of the studies were related to the use of the apparent diffusion coefficient (ADC) in the differentiation of benign lesions and malignant neoplasms. We concluded that the ADC for malignant neoplasms is lower. Histologic features of samples evaluated in the studies were heterogeneous.

CONCLUSIONS

The ADC may improve the quality of the diagnostic hypothesis, particularly in differentiating benign and malignant diseases. Furthermore, the differences between certain types of lesions could be determined by using the ADC. However, further studies focusing on inflammatory diseases should be performed. Overall, DWI and the ADC are promising methods that can be incorporated into routine evaluations.

Diffusion-Weighted Magnetic Resonance Imaging in Maxillary Sinuses Inflammatory Diseases: Report of Three Cases and Literature Review

Background

Magnetic resonance imaging is considered a preferable imaging examination in the diagnosis of inflammatory maxillary sinus disease and can provide precise sinonasal characterization. Diffusion-weighted magnetic resonance imaging and apparent diffusion coefficient are complementary magnetic resonance imaging tools that can be applied to the differentiation of sinus diseases. In this report, 3 cases of inflammatory maxillary sinus diseases imaging findings considering diffusion-weighted magnetic resonance imaging features were described. Additionally, a literature review considering the use of diffusion-weighted magnetic resonance imaging in inflammatory lesions is provided.

Methods

The cases reported were: presence of air-fluid levels, mucosal thickening and a mucous retention cyst. Conventional magnetic resonance imaging and apparent diffusion coefficient (ADC) maps, with ADC values were demonstrated. In the literature review, the studies considering inflammatory lesions were detailed, as well as ADC values established by investigators.

Results

ADC values for presence of air-fluid levels, mucosal thickening and mucous retention cyst were respectively: 1.99 x 10^-3 mm²/s; 1.83 x 10^-3 mm²/s; 2.05 x 10^-3 mm²/s.

Conclusions

It was observed that apparent diffusion coefficient values from the inflammatory lesions described in this report were different and apparent diffusion coefficient may be useful in the differentiation of these maxillary sinus alterations. Further larger sample investigations considering apparent diffusion coefficient values focusing in inflammatory lesions are recommended. The lack of studies considering the use of diffusion-weighted magnetic resonance imaging on inflammatory diseases diagnostic was the major limitation to the literature review.

Anatomic Variations in Paranasal Sinuses of Patients With Sinonasal Polyposis: Radiological Evaluation

OBJECTIVE

Although sinonasal anatomic variations have been postulated as a risk factor for sinus disease, the role of anatomic abnormalities in the pathogenesis of nasal polyps is still unclear. This study was conducted to examine the association of sinonasal polyposis with anatomic variations.

METHODS

The paranasal sinus computerized tomography scans of 155 patients with sinonasal polyposis were examined retrospectively from January 2012 to 2014 in a tertiary care hospital. Paranasal sinus computerized tomography of 100 patients without complaints and signs of sinus disease were also included to serve as control group. The incidence of anatomic variations was evaluated. The sinonasal polyposis and control group data was compared statistically.

RESULTS

The incidence of the septal deviation, concha bullosa, Agger nasi, frontal sinus hypoplasiaand accessory sinus ostium in healthy subjects, and sinonasal polyposis patients revealed statistically significant difference. The mentioned variations were found significantly higher in sinonasal polyposis patients (P = 0.000, P = 0.000, P = 0.001, P = 0.002, and P = 0.035 respectively) and may be predisposing for this pathology.

CONCLUSION

Considering the results obtained, the presence of septal deviation, concha bullosa, Agger nasi cell, frontal sinus hypoplasiaand accessory sinus ostium may play role in pathogenesis of sinonasal polyposis.

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.

The use of digital periapical radiographs to study the prevalence of alveolar domes

PURPOSE

In the present study, we coined the term 'alveolar dome' and aimed to demonstrate the prevalence of alveolar domes through digital periapical radiographs.

MATERIALS AND METHODS

This study examined 800 digital periapical radiographs in regard to the presence of alveolar domes. The periapical radiographs were acquired by a digital system using a photostimulable phosphor (PSP) plate. The χ(2) test, with a significance level of 5%, was used to compare the prevalence of alveolar domes in the maxillary posterior teeth and, considering the same teeth, to verify the difference in the prevalence of dome-shaped phenomena between the roots.

RESULTS

The prevalence of alveolar domes present in the first pre-molars was statistically lower as compared to the other maxillary posterior teeth (p<0.05). No statistically significant difference was observed in the prevalence of alveolar domes between the maxillary first and second molars. Considering the maxillary first and second molars, it was observed that the palatal root presented a lower prevalence of alveolar domes when compared to the distobuccal and mesiobuccal roots (p<0.05).

CONCLUSION

The present study coined the term 'alveolar dome', referring to the anatomical projection of the root into the floor of the maxillary sinus. The maxillary first and second molars presented a greater prevalence of alveolar domes, especially in the buccal roots, followed by the third molars and second pre-molars. Although the periapical radiograph is a two-dimensional method, it can provide dentists with the auxiliary information necessary to identify alveolar domes, thus improving diagnosis, planning, and treatment.

Radiological and clinical difficulties in the management of chronic maxillary sinusitis in β Thalassemic paediatric patients

INTRODUCTION

Beta thalassemia is a blood dyscrasia that caused a marked expansion of active marrow spaces and extramedullary haematopoiesis results. In these patients various alterations and abnormalities affects different body areas, including increased risk of sinusitis. The marrow expansion in the facial bones results in delay in pneumatisation of the sinuses, overgrowth of the maxillae, and forward displacement of the upper incisors with skeletal deformities. In current literature, maxillary sinuses are not deeply evaluated by CT scan studies in these kind of patients. The aim of our study was to investigate the presence of maxillary sinuses abnormalities by the use of CT in patients with beta-thalassemia major and to compare these findings with a control group free from this disease.

MATERIALS AND METHODS

A retrospective analysis of 22 paediatric patients with beta-thalassemia major and 22 control subjects without sinonasal diseases was performed. CT was done using a 64-multidetector-row CT scanner without contrast injection, obtained in axial plane using thin-slice technique. Evaluated parameters were: bone thickness of the lateral and anterior wall, density and volume of the maxillary sinuses.

RESULTS

Significant difference was found between the study group and control group in the evaluation of all the parameters examined. The maxillary sinus of β thalassemic patients was smaller respect of controls, the bone was more dense and thick in the side and anterior wall. Beta-thalassemic patients have a relative risk of 2.87 to develop a maxillary sinusitis.

DISCUSSION

In these patients there is an increased incidence of sinonasal infections due to the abnormal development of cranio facial skeleton. These bone alterations might confuse the physicians and lead to an increased rate of sinusitis diagnoses.

Unique canal communicating between both maxillary sinuses through the palatine recess with hypertrophy of sinuses

The result of an inappropriate growth of the jaws is in many cases related to abnormalities in the rest of the facial skeleton. We present a 21-year-old patient with a possibly unique anomaly of the maxillary sinus in skeletal class III dentofacial deformity. This anatomical variant has not to our knowledge been previously reported and all clinicians should be aware of it. It presented not only as hypertrophy of the sinuses but also as a communication between the two maxillary sinuses, and might be associated with a severe III class deformity with an extremely narrow maxilla. We describe this as a narrowed maxillary canal with no septum or membrane.