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

A proposal for analyzing the inflammatory and remodeling processes of mucosa in chronic rhinosinusitis with nasal polyposis through MRI

OBJECTIVES

Chronic Rhinosinusitis with Nasal Polyposis (CRSwNP) is a disease characterized by chronic inflammation and tissue remodeling process. The remodeling process in nasal polyps has mainly been studied by histology analysis. However, it is limited to a polyp fragment and requires tissue removal. The present study aims to evaluate the ability of Magnetic Resonance Imaging (MRI) to depict and characterize the remodeling process in patients with CRSwNP.

METHODS

30 patients that met clinical diagnostic criteria for CRSwNP, without previous history of rhinosinusitis surgery were submitted to MRI scan (conventional, diffusion-weighted and DCE MRI) and compared with polyp tissue histological findings, IL-6 concentrations in the tissue and eosinophil count in the blood. The examinations were evaluated, independently, by two radiologists blinded to other radiological and histological data. The pathologist, blinded to MRI results, also compared the tissue sample from the most central and the most peripheral portion of the polypoid tissue adjacent to the floor of the nasal fossa.

RESULTS

This study demonstrated a characteristic pattern of nasal polyps, whose peripheral portions of nasal polypoid tissue are edematous, whereas the central portions in the middle meatus and in the middle and upper ethmoid are predominantly fibrotic. ADC values found in the most anterior portion of the polyps may be a marker for radiological phenotyping the remodeling process. This non-invasive analysis presented a high degree of agreement in the fibrosis and edema rating by two radiologists and the histological analysis was concordant with the MRI findings. The polyps were characterized as eosinophilic, and no relationship was found between the severity of the eosinophilic inflammatory process or concentration of IL-6 and the remodeling process.

CONCLUSION

MRI by using T2-weighted imaging sequence and ADCs values allows tissue characterization and is an effective tool for the differentiation of edematous and fibrotic components in CRSwNP.

LEVEL OF EVIDENCE: 3

Inflammatory Modifications in Paranasal Sinuses and Ostiomeatal Complex Anatomical Variations in Jet Aircraft Pilots: A Computed Tomography Study

Introduction  Jet aircraft pilots are exposed to huge pressure variation during flight, which affect physiological functions as systems, such as the respiratory system. Objectives  The objective of the present investigation was to evaluate inflammatory changes of paranasal sinuses of jet aircraft pilots before and after a jet aircraft training program, using multislice computed tomography (CT), in comparison with a group of nonairborne individuals with the same age, sex, and physical health conditions. A second objective of the present study was to assess the association between the ostiomeatal complex obstruction and its anatomical variations. Methods  The study group consisted of 15 jet aircraft pilots participating in the training program. The control group consisted of 41 nonairborne young adults. The 15 fighter pilots were evaluated before initiating the training program and after their final approval for the presence of inflammatory paranasal sinus disease. The ostiomeatal complex anatomical variations and obstructions were analyzed in pilots after the training program. Results  Jet aircraft pilots presented higher incidence of mucosal thickening in maxillary sinus and anterior ethmoid cells than controls. Prominent ethmoidal bulla showed significant association with obstruction of the osteomeatal complex. Conclusions  Jet aircraft pilots present increased inflammatory disease when compared with nonairborne individuals. The presence of a prominent ethmoidal bulla is associated with ostiomeatal complex obstruction.

Evaluation of the efficacy of diffusion-weighted magnetic resonance imaging and apparent diffusion coefficients in the diagnosis of maxillary diseases

OBJECTIVE

We investigated the efficacy of using diffusion-weighted imaging (DWI) with quantitative apparent diffusion coefficient (ADC) mapping in the diagnosis of maxillary diseases.

STUDY DESIGN

We evaluated 146 cases of maxillary diseases (32 malignant tumors, 11 benign tumors, 28 maxillary cysts, 60 cases of maxillary sinusitis, and 15 maxillary sinus retention cysts) that had been examined using magnetic resonance imaging. The DWI sequence was obtained with b values of 0 and 800 s/mm2 and ADC values were calculated. We used one-way analysis of variance and the Tukey honestly significant difference test to identify differences within and between the types of diseases.

RESULTS

Mean ADC values for malignant tumors (1.07 × 10-3 mm2 s-1) were significantly lower than ADCs for benign tumors (1.85 × 10-3 mm2 s-1), maxillary cysts (1.77 × 10-3 mm2 s-1), maxillary sinusitis (2.34 × 10-3 mm2 s-1), and maxillary sinus retention cysts (2.52 × 10-3 mm2 s-1), with P < 0.001.   Mean ADC differed significantly between all disease types except between maxillary sinusitis and maxillary sinus retention cysts. ADC values also significantly differed between specific lesions within the malignant tumor and maxillary cyst groups.

CONCLUSIONS

The use of ADC values can be useful in the differential diagnosis of malignant maxillary diseases, benign lesions, cysts, and inflammatory and reactive conditions.

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.

Magnetic resonance imaging study of incidental findings in the paranasal sinuses and ostiomeatal complex

Purpose

This study aimed to assess incidental abnormal findings in the paranasal sinuses and anatomical variations of the ostiomeatal complex (OMC) on magnetic resonance imaging (MRI) scans.

Materials and Methods

MRI scans of 616 patients (mean age, 44.0±19.4 years) were evaluated. Prior to obtaining the MRI scans, a checklist of patients’ clinical symptoms was filled out after obtaining their consent. The Lund-Mackay classification was used to assess the paranasal sinuses and OMC. The prevalence of abnormal findings and their associations with patients’ age, sex, and subjective symptoms were analyzed by the chi-square test, independent-sample t-test, and analysis of variance. The level of significance was set at 0.05.

Results

Abnormal findings in the paranasal sinuses were detected in 32.0% of patients, with a significantly higher prevalence in males (P<0.05), but no significant association with age (P>0.05). Epithelial thickening and retention cyst were the most common abnormal findings in the paranasal sinuses. According to the Lund-Mackay classification, 93% of the study population had normal sinuses (score<4). Concha bullosa and paradoxical concha were detected in 15.3% and 3.4%, respectively, with no significant association with the presence of septal deviation or Lund-Mackay classification (P>0.05).

Conclusion

Considering the relatively high prevalence of abnormal findings in the paranasal sinuses, it appears that clinical symptoms alone are not sufficient to diagnose sinusitis. A more accurate strategy would be to assess radiographic images of the paranasal sinuses and use a classification system. Sinusitis should be suspected in patients receiving a high score in this classification.

An Update of the Possible Applications of Magnetic Resonance Imaging (MRI) in Dentistry: A Literature Review

This narrative review aims to evaluate the current evidence for the application of magnetic resonance imaging (MRI), a radiation-free diagnostic exam, in some fields of dentistry.

BACKGROUND

Radiographic imaging plays a significant role in current first and second level dental diagnostics and treatment planning. However, the main disadvantage is the high exposure to ionizing radiation for patients.

METHODS

A search for articles on dental MRI was performed using the PubMed electronic database, and 37 studies were included. Only some articles about endodontics, conservative dentistry, implantology, and oral and craniofacial surgery that best represented the aim of this study were selected.

RESULTS

All the included articles showed that MRI can obtain well-defined images, which can be applied in operative dentistry.

CONCLUSIONS

This review highlights the potential of MRI for diagnosis in dental clinical practice, without the risk of biological damage from continuous ionizing radiation exposure.

Diffusion-weighted magnetic resonance imaging of mandibular bone marrow: do apparent diffusion coefficient values of the cervical vertebrae and mandible correlate with age?

OBJECTIVES

The objective of this investigation was to assess the correlation between the mandible and cervical vertebrae bone marrow apparent diffusion coefficient (ADC), obtained by diffusion-weighted magnetic resonance imaging (DWI), with age; to verify the correlation between ADC values from the mandible and the cervical vertebrae; to describe and assess the differences between ADC values obtained from DWI examinations of distinct mandible areas as well as cervical vertebrae.

METHODS

Thirty imaging examinations with DWI for that included the mandible and C1, C2, C3, and C4 vertebrae in the same examination were included. ADC values were collected from 7 distinct areas in the mandible and the cervical vertebrae. Differences between ADC values and non-parametric correlations were performed.

RESULTS

A total of 270 regions were assessed. No significant difference was found between ADC values of all areas tested. An inverse correlation was found between C2, C3, and C4 vertebrae ADC values and age. The significant correlation of anatomic area ADC values and age were presented as graphics to verify if the linear trend of ADC values and age are in accordance with the literature CONCLUSIONS: The mandible area that most correlates with the cervical vertebrae, using ADC values, is the posterior trabecular area, below the inferior molars. Also, C2, C3, and C4 vertebrae ADC values inversely correlate with age, which demonstrates the bone qualitative changes in bone composition. ADC values may be useful for the qualitative assessment of bone quality to screen patients at osteoporosis risk.

Independent risk factors associated with higher mortality rates and recurrence of brain abscesses from head and neck sources

OBJECTIVE

The aim of this study was to identify the features and independent risk factors associated with recurrence and mortality in patients with brain abscesses of head and neck origin.

STUDY DESIGN

We designed a retrospective study of patients diagnosed with a brain abscess at the Massachusetts General Hospital between 1980 and 2017. Inclusion criteria were complete medical records, including medical and surgical history; and radiographic and microbiologic data. Multinomial logistic regression and Gray's test were used to evaluate the independent variables associated with recurrence and mortality.

RESULTS

Eighty-eight cases met the inclusion criteria. Of these, 48 patients (54.5%) were men (mean age 50.5 ± 18.8 years). Significant association between etiology and cultured organisms was found only in cases of neurosurgical intervention with staphylococcal or streptococcal isolates (P < .05). Seizure activity was the only significant predictor of recurrence. Predictors of mortality included advanced age (P = .005); staphylococcal infection (P = .029); low monocyte count (P = .004); hyponatremia (P = .002); elevated blood urea nitrogen (P = .000); elevated creatinine (P = .002); hyperglycemia (P = .023); and status at discharge (P = .000).

CONCLUSIONS

Independent risk factors, such as low monocyte count, hyponatremia, renal dysfunction, and hyperglycemia, were found to be associated with higher mortality rates in patients with brain abscesses of head and neck origin. These abnormalities should be promptly recognized and aggressively treated.

Can Diffusion-Weighted Imaging Serve as an Imaging Biomarker for Acute Bacterial Rhinosinusitis?

Acute rhinosinusitis is defined as symptomatic inflammation of the mucosal lining of the nasal cavity and paranasal sinuses lasting less than four weeks. It is most commonly secondary to viral infection but is often challenging to distinguish from bacterial etiologies. Even with recommendations from several specialty societies, there continues to be a frequent practice of overprescribing oral antibiotics for acute rhinosinusitis, thus leading to multidrug-resistant organisms, and rendering oral medication useless when actually clinically warranted. We observed a potential non-invasive imaging biomarker that could predict which patients would benefit from anti-microbial therapy. Often computed tomography (CT) imaging is obtained by the provider before consultation with the otolaryngologist, sometimes leading to unnecessary radiation to the patient. In addition, there are no clear CT findings to make the diagnosis of acute rhinosinusitis. The diagnosis is challenging for all clinicians involved, and therefore, additional signs on other imaging modalities would be helpful. We present a series of four patients with incidentally discovered culture-positive acute rhinosinusitis. Patients with incidentally discovered culture-positive acute rhinosinusitis were found to also have magnetic resonance imaging (MRI) that showed corresponding restricted diffusion on diffusion-weighted imaging (DWI). An imaging biomarker for acute bacterial rhinosinusitis may improve the appropriate use of antibiotic therapy. DWI MRI should be further investigated as a potential candidate screening modality.

Application of diffusion-weighted magnetic resonance imaging in the diagnosis of odontogenic lesions: a systematic review

OBJECTIVES

This systematic literature review addresses the use of diffusion-weighted magnetic resonance imaging (DWI) and apparent diffusion coefficient (ADC) for the evaluation of benign maxillomandibular odontogenic lesions.

STUDY DESIGN

Databases were searched, and original research studies or case report manuscripts up to April 2019 were included, using the keyword "diffusion," combined with the keywords "maxillofacial pathology," "oral pathology," "odontogenic tumors," "dental tissue neoplasms," "odontogenic cysts," and the histologic denomination of benign odontogenic lesions, according to the World Health Organization classification. Only English language articles and studies pertaining to DWI were selected.

RESULTS

Fifteen investigations (11 original articles and 4 case reports) of distinct benign odontogenic lesions were included. Most studies did not include exclusively odontogenic lesions in their samples.

CONCLUSIONS

It is too early to reach a conclusion that DWI and ADC can provide useful information in the differentiation of the histologic type of some benign odontogenic lesions on the basis of available data in the literature.