Radiological imaging of inflammatory lesions in the nasal cavity and paranasal sinuses

Advanced imaging of head and neck infections

When head and neck infection is suspected, appropriate imaging contributes to treatment decisions and prognosis. While contrast-enhanced CT is the standard imaging modality for evaluating head and neck infections, MRI can better characterize the skull base, intracranial involvement, and osteomyelitis, implying that these are complementary techniques for a comprehensive assessment. Both CT and MRI are useful in the evaluation of abscesses and thrombophlebitis, while MRI is especially useful in the evaluation of intracranial inflammatory spread/abscess formation, differentiation of abscess from other conditions, evaluation of the presence and activity of inflammation and osteomyelitis, evaluation of mastoid extension in middle ear cholesteatoma, and evaluation of facial neuritis and labyrinthitis. Apparent diffusion coefficient derived from diffusion-weighted imaging is useful for differential diagnosis and treatment response of head and neck infections in various anatomical sites. Dynamic contrast-enhanced MRI perfusion may be useful in assessing the activity of skull base osteomyelitis. MR bone imaging may be of additional value in evaluating bony structures of the skull base and jaw. Dual-energy CT is helpful in reducing metal artifacts, evaluating deep neck abscess, and detecting salivary stones. Subtraction CT techniques are used to detect progressive bone-destructive changes and to reduce dental amalgam artifacts. This article provides a region-based approach to the imaging evaluation of head and neck infections, using both conventional and advanced imaging techniques.

Diagnosis and management of extramedullary plasmacytoma in nasal cavity: Clinical experience and literature review

Nasal extramedullary plasmacytoma (EMP) is a rare plasma cell tumor that occurs in the soft tissue of the nasal cavity, and its imaging characteristics are still unclear. The purpose of this study was to investigate the clinical features, imaging findings, treatment, survival analysis, and prognosis of nasal EMP, and to provide a systematic review of the patients we treated and the published literature. A 45-year-old female patient who presented with epistaxis with nasal obstruction was recommended for magnetic resonance imaging to assess the nature of the lesion. On magnetic resonance imaging, abnormal signal shadow can be seen in the right nasal cavity. Diffusion weighted imaging showed signal of the lesion was significantly limited, presenting high signal, with a low apparent dispersion coefficient, and the lesion was significantly enhanced on contrast-enhanced scan. Combined with the clinical manifestations of the patient, who was initially considered to have a hemangioma. She underwent endoscopic nasal surgery under general anesthesia to remove the mass, and the final pathology confirmed it was EMP. However, the final pathology confirmed EMP. Five months later, the patient came to our hospital for follow-up and underwent fluorine-18-fluorodeoxyglucose/positron emission tomography/computed tomography scan, which showed no recurrence of the lesion and no transformation of multiple myeloma. The nasal EMP imaging findings were mostly soft tissue masses with uniform density or signal, which were significantly enhanced by enhancement scan, high signal on diffusion weighted imaging and low signal on apparent dispersion coefficient. Immunohistochemical staining for CD38, CD138, and CD79a was positive in most of the cases evaluated, while CD20 and CD10 were negative. The absence of dilated features, infiltrative features and the presence of significant contrast enhancement may be relatively specific imaging findings of nasal EMP. The prognosis of nasal EMP is good, and recurrence, metastasis, and transformation into multiple myeloma are rare. Because the lesions are sensitive to radiotherapy, surgical resection combined with radiotherapy is a more effective treatment.

Anatomical Characteristics of the Accessory Maxillary Ostium in Three-Dimensional Analysis

Background and Objectives: The accessory maxillary ostium (AMO) can interfere with ventilation and drainage of the maxillary sinus, and therefore the importance of evaluating the anatomical features of the AMO has been emphasized. This study aimed to evaluate anatomical characteristics of the AMO together with the natural ostium (NO) using three-dimensional (3D) analysis and to assess the relationship between the AMO and maxillary sinus pathologies. Materials and Methods: This retrospective study included 394 sinuses in 197 patients. Using 3D computed tomography images, the prevalence of the AMO and concurrent sinus pathologies were examined. For patients with an AMO, 3D spatial positions of the AMO and NO related to adjacent anatomic structures and dimensions of the AMO and NO were evaluated. Results: A total of 84 sinuses showed single or multiple AMO, with a prevalence of 21.3%. The AMO was located superiorly by 30.1 mm from the maxillary sinus floor, inferiorly by 1.3 mm from the orbital floor, and posteriorly by 22.4 mm from the anterior sinus wall. The AMO was located 5.4 mm posteriorly and 0.7 mm inferiorly from the NO. On the same coronal plane as the NO or AMO, height from the maxillary sinus floor to the NO and AMO ranged from 19.4 to 45.8 mm and 14.5 mm to 41.9 mm, respectively. The mean horizontal and vertical dimensions were 5.9 mm and 4.6 mm for the NO and 2.8 mm and 3.0 mm for the AMO. We detected a significant association between the presence of the AMO and the mucosal thickening (p = 0.029). Conclusions: The results of this study suggest that, although the AMO and NO are mostly located in positions that do not limit sinus-related surgeries, such as maxillary sinus floor augmentation, the AMO and NO are also found in lower positions, which may be a detriment to the postoperative physiological function of the maxillary sinus and affect treatment outcomes.

Neuroradiological Basis of COVID-19 Olfactory Dysfunction: A Systematic Review and Meta-Analysis

Objective

Olfactory dysfunction (OD) is a common presenting symptom of COVID‐19 infection. Radiological imaging of the olfactory structures in patients with COVID‐19 and OD can potentially shed light on its pathogenesis, and guide clinicians in prognostication and intervention.

Methods

PubMed, Embase, Cochrane, SCOPUS were searched from inception to August 1, 2021. Three reviewers selected observational studies, case series, and case reports reporting radiological changes in the olfactory structures, detected on magnetic resonance imaging, computed tomography, or other imaging modalities, in patients aged ≥18 years with COVID‐19 infection and OD, following preferred reporting items for systematic reviews and meta‐analyses guidelines and a PROSPERO‐registered protocol (CRD42021275211). We described the proportion of radiological outcomes, and used random‐effects meta‐analyses to pool the prevalence of olfactory cleft opacification, olfactory bulb signal abnormalities, and olfactory mucosa abnormalities in patients with and without COVID‐19‐associated OD.

Results

We included 7 case–control studies (N = 353), 11 case series (N = 154), and 12 case reports (N = 12). The pooled prevalence of olfactory cleft opacification in patients with COVID‐19 infection and OD (63%, 95% CI = 0.38–0.82) was significantly higher than that in controls (4%, 95% CI = 0.01–0.13). Conversely, similar proportions of cases and controls demonstrated olfactory bulb signal abnormalities (88% and 94%) and olfactory mucosa abnormalities (2% and 0%). Descriptive analysis found that 55.6% and 43.5% of patients with COVID‐19 infection and OD had morphological abnormalities of the olfactory bulb and olfactory nerve, respectively, while 60.0% had abnormal olfactory bulb volumes.

Conclusion

Our findings implicate a conductive mechanism of OD, localized to the olfactory cleft, in approximately half of the affected COVID‐19 patients. Laryngoscope, 132:1260–1274, 2022

Imaging of pediatric nasal masses: A review

Several conditions may present as nasal masses in pediatric age, including congenital and developmental disorders, inflammatory and infectious conditions, neoplastic and neoplastic-like lesions, and other miscellaneous disorders. A confident presurgical diagnosis can be challenging and imaging is often key in the management of these lesions. We provide a pictorial review of pediatric nasal masses and discuss a location-based approach to the diagnosis of these lesions on imaging studies. Acquaintance with the most common pathologies and awareness for its characteristic imaging features can aid the physician in the differential diagnosis. Location and extension of the lesion can be particularly helpful. Midline masses raise suspicion for developmental nasal midline lesions, including frontoethmoidal cephalocele, dermoid/epidermoid cyst, and neuroglial heterotopia. In case of trauma, nasal septum hematoma/abscess should be considered. Developmental or odontogenic cystic lesions and osseous neoplasms and neoplasm-like lesions can originate from the maxilla and palate. Although most nasal tumors show overlapping imaging characteristics, some have suggestive features, such as nasopharyngeal angiofibroma and esthesioneuroblastoma. Malignant tumors tend to be locally aggressive, demonstrating invasive features, bony erosion, intermediate signal on T2-weighted images, and restricted diffusion on diffusion-weighted imaging. In certain cases, a definite diagnosis can only be made histologically. Nonetheless, detailed characterization of the lesion is crucial prior to invasive procedures in order to avoid complications.

Comparison of MRI and CT in the Evaluation of Unilateral Maxillary Sinus Opacification

Objectives

To evaluate the diagnostic performance of MRI compared with CT in differentiating neoplastic from infectious/inflammatory causes of complete unilateral maxillary sinus opacification (UMSO). Although MRI is increasingly used, no studies validate its utility compared to CT or nasal endoscopy in this context.

Methods

A retrospective analysis of 49 patients presenting with complete UMSO to a tertiary referral centre was performed, investigated with both CT and MRI. Two head and neck radiologists independently reviewed each imaging modality and recorded both a final diagnosis and Likert-scale diagnostic certainty score. A consensus radiological diagnosis was determined, stratified into potentially neoplastic or infectious/inflammatory aetiology, and compared with nasal endoscopy and final diagnosis. Diagnostic performance and interoperator agreement for predicting neoplasia were calculated.

Results

Both CT and MRI demonstrated high sensitivity and negative predictive value for neoplasm, although MRI was more specific (79%; 95% CI: 60–92%) than CT (14%; 95% CI: 4–32%), with a higher positive predictive value. MRI was more accurate (88%; 95% CI: 75–95%) than CT (49%; 95% CI: 34–64%) in diagnosing neoplasia. MRI had significantly higher diagnostic certainty Likert scores than CT (p < 0.0001 for both observers). Interobserver agreement was fair for CT (kappa coefficient = 0.327) and excellent for MRI (kappa coefficient = 0.918).

Conclusions

MRI is more specific than CT in characterising UMSO, with greater diagnostic certainty and reproducibility. The additive diagnostic value of MRI complements CT, potentially reducing diagnostic delays in some cases and the need for diagnostic endoscopic sinus surgery in others. We recommend MRI incorporation into the diagnostic pathway for patients with UMSO.

Clinical features in maxillary sinus fungus ball in patients with malignant hematological disease

PURPOSE

Previous studies on fungus balls have primarily focused on immunocompetent patients, and only a few studies have described the clinical characteristics of fungus balls in malignant hematological disease (MHD) patients. Therefore, we compared the clinical features of maxillary sinus fungus ball (MSFB) between immunosuppressive patients with MHD and immunocompetent patients.

METHODS

Twenty patients with MHD and 40 randomly selected immunocompetent patients were enrolled and divided into MHD and non-MHD groups. All patients were diagnosed with MSFB and their clinical features were retrospectively analyzed.

RESULTS

Patients in the MHD group had non-specific clinical symptoms and endoscopic manifestations of MSFB, similar to those in the non-MHD group. On computed tomography (CT), the MHD group showed higher Lund-Mackay scores, lesser single sinus opacifications, more multiple sinus opacifications on the affected side, and more bilateral opacifications compared to the non-MHD group. The MHD group had a lower frequency of central hyper-density and heterogeneous opacifications than the non-MHD group. There were no significant differences between the two groups in terms of the fungal-infected side, lateral sinus wall ratio, sclerosis of the lateral sinus wall, erosion of the inner sinus wall, and nasal septum deviation.

CONCLUSION

The clinical symptoms and endoscopic manifestations of MSFB in patients with MHD were similar to those of immunocompetent patients. However, more atypical signs and wider mucosal inflammation were found on CT scans of MSFB patients with MHD. These results indicate that caution should be executed when excluding the possibility of fungus balls in immunosuppressive patients.

Ultrasound Imaging versus Radiographs in Differentiating Periapical Lesions: A Systematic Review

BACKGROUND

Ultrasonography is a non-invasive method of diagnosing periapical lesions while radiologic methods are more common. Periapical lesions due to endodontic infection are one of the most common causes of periapical radiolucency that need to be distinguished to help determine the course of treatment. This review aimed to examine the accuracy of ultrasound and compare it to radiographs in distinguishing these lesions in vivo.

METHODS

This review process followed the PRISMA guidelines. A literature search of databases (PubMed, Scopus, Embase, and Web of Science) was conducted without any restrictions on time. Articles available in English were included. The selection was done according to the inclusion and exclusion criteria. The QUADAS-2 tool was used to assess the quality of the studies.

RESULTS

The search provided a total of 87 articles, out of which, five were selected for the final review. In all the studies, ultrasound had higher accuracy in distinguishing periapical lesions. All the studies indicated a risk of bias, especially in patient selection.

CONCLUSION

Within limitations, the study indicates that ultrasound is a better diagnostic tool to distinguish periapical lesions compared to radiographs but further studies with well-designed, rigorous protocols and low risk of bias are needed to provide stronger evidence.

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 and Clinical Significance of Radiographic Sinus Disease on Preoperative Computed Tomography Imaging in the Endoscopic Skull Base Surgery Population

INTRODUCTION

Endoscopic skull base surgery (ESBS) provides a safe, minimally invasive approach to treat benign and malignant skull base lesions. The significance of concomitant sinonasal pathology on imaging in patients undergoing ESBS and its effect on perioperative management is not well described. We sought to identify the prevalence and clinical significance of incidentally found radiographic sinus disease on preoperative imaging in patients undergoing ESBS and provide a protocol for management of these patients.

DESIGN

A retrospective chart review was performed of consecutive patients who underwent ESBS from January 1, 2016 to June 30, 2018. Preoperative computed tomography (CT) scans were reviewed and scored using the Lund-Mackay (LM) staging system. Preoperative nasal endoscopy findings were analyzed. Any preoperative treatment based on these findings and changes in intraoperative management were examined.

RESULTS

A total of 156 patients (81 women, 74 men) who underwent ESBS were reviewed. The average LM score was 2 ± 2.7 (range: 0-12). A total of 94 patients (60.3%) had evidence of radiographic sinus disease (LM score > 0) and 23 patients (14.7%) had presence of sphenoid sinus disease. Seven patients (4.5%) were treated preoperatively based on CT and/or nasal endoscopy findings. All patients who received preoperative treatment had evidence of sinus disease on imaging with an average score of 4.7 and were evaluated and treated within 1-2 weeks prior to ESBS. One patient had ESBS postponed until endoscopic sinus surgery was performed for extensive chronic rhinosinusitis (CRS) findings on imaging.

CONCLUSION

A review of preoperative imaging in patients undergoing ESBS can help identify concurrent sinonasal disease, which has the potential to alter preoperative as well as intraoperative management in these patients. We report a diligent but conservative approach for the treatment of concomitant CRS in the ESBS population with decision for preoperative treatment guided by various factors.

Comparative studies on the histological characteristics of equine nasomaxillary aperture and paranasal sinus mucosa considering topographic and age-related differences

Background

Horses may acquire a range of paranasal sinus diseases. Clinical studies show slight differences regarding anatomical regions and age. Histopathological examination of tissue samples could play an important role in the diagnostic process. Therefore, detailed knowledge of the histological appearance of the paranasal sinus mucosa (PSM) and the nasomaxillary aperture mucosa (NAM) is essential. The objective of this study was to determine topographic and age-related differences within the healthy equine PSM. In addition, we aimed to gain detailed knowledge of the histological appearance of the NAM in comparison to the PSM.

Results

The PSM had an average height of 75.72 ± 44.48 μm with a two-row pseudostratified columnar epithelium of 13.52 ± 4.78 μm. The parameters mucosal height, epithelial height and number of goblet cells revealed significant dependency of the sample site and age group. The maxillary and dorsal conchal sinus showed the highest values for these parameters. In terms of age, younger horses showed a significantly higher total mucosal height in contrast to a significantly lower epithelial height than older horses. Positive correlation was seen between the epithelial height and number of goblet cells. The NAM had an average height of 820.27 ± 653.21 μm. Its pseudostratified epithelium was usually arranged in three rows and had an average height of 44.9 ± 12.78 μm. The number of goblet cells in the NAM was five times higher than in the PSM. Serous glands were found in only 4% of the PSM samples and 100% of the NAM samples.

Conclusions

There are significant histological differences between different paranasal sinus sites and between different groups of age. This may be related to an altered susceptibility for certain pathologies. The striking difference in the histological appearance of the NAM compared to the PSM could be due to an enhanced role in mucociliary clearance. Further studies are necessary to improve the understanding of mucosal function in specific paranasal sinus compartments and mucosal changes generated by different diseases.

Chronic invasive fungal rhinosinusitis vs sinonasal squamous cell carcinoma: the differentiating value of MRI

OBJECTIVES

To investigate MRI features in discriminating chronic invasive fungal rhinosinusitis (CIFRS) from sinonasal squamous cell carcinomas (SNSCC).

METHODS

MRI findings of 33 patients with CIFRS and 47 patients with SNSCC were retrospectively reviewed and compared. Multivariate logistic regression analysis was performed to identify significant imaging features in distinguishing between CIFRS and SNSCC. The ROC curves and the AUC were used to evaluate diagnostic performance.

RESULTS

There were significant differences in cavernous sinus involvement (p < 0.001), sphenoid sinus involvement (p < 0.001), meningeal involvement (p = 0.024), T2 signal intensity (p = 0.006), and enhancement pattern (p < 0.001) between CIFRS and SNSCC. Multivariate logistic regression analysis identified cavernous sinus involvement (odds ratio [OR] = 0.06, 95% confidence interval [95% CI] = 0.02-0.20) and sphenoid sinus involvement (OR = 0.14, 95% CI = 0.05-0.45) as significant indicators for CIFRS and T2 isointensity to gray matter (OR = 4.44, 95% CI = 1.22-16.22) was a significant indicator for SNSCC. ROC curve analysis showed the AUC from a combination of three imaging features was 0.95 in differentiating CIFRS and SNSCC.

CONCLUSIONS

MRI showed significant differences between CIFRS and SNSCC features. In immunocompromised patients, a sinonasal hypointense mass on T2WI with septal enhancement or loss of contrast enhancement, and involvement of cavernous sinus, sphenoid sinus, and meninges strongly suggest CIFRS.

KEY POINTS

• Chronic invasive fungal rhinosinusitis (CIFRS) is often difficult to distinguish from sinonasal squamous cell carcinomas (SNSCC) in clinical practice. • Cavernous sinus and sphenoid sinus involvement appear to be significant indicators for CIFRS. T2 isointensity to gray matter appears to be a significant indicator for SNSCC. • Loss of contrast enhancement and septal enhancement can be used to distinguish CIFRS from SNSCC with a high degree of specificity.

MR Findings of Fungus Ball: Significance of High Signal Intensity on T1-Weighted Images

BACKGROUND

Central dark-signal intensity with high-signal, hypertrophic mucosal wall of paranasal sinuses on T2-weighted images (T2WI) is a characteristic magnetic resonance imaging (MRI) feature of sinonasal fungus ball. However, this finding is usually interpreted as non-fungal chronic sinusitis with central normal sinus air. In addition, T1-weighted images (T1WI) and T2WI are basic sequences of all magnetic resonance (MR) examinations. Therefore, we evaluated the usefulness of T1WI for detecting fungus balls comparing with computed tomography (CT) findings and T2-weighted MRI findings.

METHODS

This retrospective study was approved by the Institutional Review Board of Korea University Guro Hospital. Two reviewers assessed preoperative CT and MR images of 55 patients with pathologically confirmed fungus balls. Reviewers evaluated the presence and patterns of calcifications on CT. Overall signals and the presence and extent of certain signals of fungus balls on MRI were also assessed. The relationship between calcifications and MRI signals was also evaluated.

RESULTS

Of the patients, 89.1% had calcifications on CT. All had dark signal portions with high signal, hypertrophic mucosal walls on T2WI. Most (92.7%) patients showed iso- to hyper-intense overall signals on T1WI and 89.1% had T1-weighted high signal portions on MRI. The presence, patterns, and location of calcifications had no significant correlation with T1-weighted high-signal intensity portion.

CONCLUSION

Fungus ball can be suggested by the presence of the hyper-signal intensity portions in the fungal mass on T1WI in conjunction with dark-signal lesions surrounded by high-signal, hypertrophic mucosal walls in paranasal sinuses on T2WI.

Pyogenic granuloma gravidarum: a case in the nasal cavity and the use of MRI as a preoperative surgical aide

Pyogenic granuloma gravidarum is a benign fibrovascular proliferative lesion usually involving the oral gingivae in pregnant patients. While it also occurs, although less frequently, on other oral sites such as lips, tongue and palate, it is relatively unusual to find it in the nasal cavity. Furthermore, lesions normally involute spontaneously after childbirth. For persistent lesions requiring surgical management, imaging has historically been limited to CT. This case is notable not only for its uncommon location but also for its recurrent nature, failure to regress post partum and the use of MRI in the preoperative planning.

An Evaluation of Bone Mineral Density Using Cone Beam Computed Tomography in Patients with Ectodermal Dysplasia: A Retrospective Study at a Single Center in Turkey

BACKGROUND The aim of this retrospective study was to compare the measurements of bone mineral density (BMD) combined with volumetric dental tomography measurements taken from three main regions selected on the lower mandible, the right mandibular, medial mandibular, and left mandibular regions, in patients with ectodermal dysplasia and age-matched and gender-matched controls. Measurement of BMD in Hounsfield units (HUs) were evaluated using three-dimensional (3D) cone beam computed tomography (CBCT) imaging. MATERIAL AND METHODS Mandibular bone tomography images were evaluated from 9 women and 5 men diagnosed with ectodermal dysplasia and a control group of 9 women and 5 men. The HU values obtained according to age and gender of the total 28 study participants were measured. Statistical analysis of the data used Student's t-test. RESULTS BMD in the ectodermal dysplasia group was significantly lower compared with the BMD in the control group. Comparison of the left and right mandibular angulus regions showed that the BMD of patients with ectodermal dysplasia was significantly lower when compared with the control group in both regions, but no significant difference was found between the two groups in the BMD of the central mandibular region. CBCT was found to be an effective method for the measurement of BMD. CONCLUSIONS In patients with ectodermal dysplasia, reduced BMD should be taken into consideration when planning surgical interventions involving bone tissue and when planning implant surgery. The results of this study may be of value in dentistry and other fields of medicine.

LOW-DOSE COMPUTED TOMOGRAPHY OF THE PARANASAL SINUSES: PERFORMANCE OF TWO DIFFERENT ITERATIVE RECONSTRUCTION ALGORITHMS

To evaluate the performance of two iterative reconstruction algorithms in low-dose paranasal sinus computed tomography (CT). Sinus CT scans were reconstructed using Adaptive Iterative Dose Reduction 3D (AIDR 3D, n = 36 patients) or Sinogram Affirmed Iterative Reconstruction (SAFIRE, n = 32 patients). Reconstructed images were evaluated regarding subjective image quality, depiction of anatomic landmarks and noise (HU). Dose-length product (DLP), calculated effective dose (ED) and CT dose index (CTDIvol) were documented for each scan. Images were not significantly different in subjective image quality (p = 0.09) and conspicuity of anatomic landmarks (p = 0.28). Noise was significantly lower in images reconstructed with AIDR 3D (p = 0.012). DLP, ED and CTDIvol were significantly lower in the SAFIRE datasets (each p < 0.001). The results indicate that iterative reconstruction, independent of the manufacturer, enables for imaging the paranasal sinuses with an ED below 0.1 mSv while ensuring diagnostic image quality.

First report of lateral nasal wall pneumatization

Pneumatization is defined as air-filled cavities inside bone tissue. It is an anatomic variation such asymptomatic radiolucent defects that can be unilateral and multilocular in healthy individuals. The skull contains numerous pneumatized regions including paranasal sinuses, nasal cavity, zygomatic arch and temporal bone. 38-year-old female patient was referred to our clinic with a complaint of upper third molar pain. A radiolucent area was observed in left nasal region during panoramic radiograph examination. In cone beam computed tomography images, a pneumatization within mucosal thickening was diagnosed in left nasal wall. This case report describes anatomic and morphologic features of lateral nasal wall pneumatization with cone beam computed tomographic images.

Three-dimensional evaluation of maxillary sinus volume in different age and sex groups using CBCT

AIM

Sinus maxillaris is an important anatomical formation in many branches of dentistry due to its proximity to the field of work. Various methods have been used in literature to measure the maxillary sinus volume (MSV) such as cadavers, stereology, two-dimensional conventional radiographs, computed tomography (CT), magnetic resonance imaging (MRI). The aim of this study is to evaluate the change of maxillary sinus volume according to age and gender with MIMICS 19.0 (Materialise HQ Technologielaan, Leuven, Belgium) which is one of three-dimensional modeling software.

MATERIALS AND METHODS

This study was performed in 200 patients selected by a retrospective review of the archives of the Dicle University, Faculty of Dentistry, Department of Oral and Maxillofacial Radiology. Patients were divided into five age groups (18-24 years, 25-34 years, 35-44 years, 45-54 years, and ≥ 55 years) and by sex. Cone-beam computed tomography (CBCT) images of the patients were transferred to the MIMICS software and the MSV was measured. All statistical analyses were performed using the SPSS (Statistical Package for Social Sciences, version 21) software.

RESULTS

There was no statistically significant difference between the right and left maxillary sinus volume according to the findings obtained from our study, and maxillary sinus volume in males was found to be significantly higher than that of females. Another finding of our study is that the maxillary sinus volume decreases with age increase. Especially it was also found that the sinus volume in males in the 18-24 age group was statistically significantly higher than females.

CONCLUSION

Consequently, maxillary sinus volume measurements can be made on CT, CBCT, MRI scans using reconstruction software.

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.

Thickness of the Schneiderian membrane and its correlation with anatomical structures and demographic parameters using CBCT tomography: a retrospective study

Background

The aims of the present study were to determine the thickness of the Schneiderian membrane and identify the width of the maxillary sinus, which is indicated by the buccal and lingual walls of the sinus angle between. Furthermore, to investigate the possibility of a correlation between the aforementioned structures and also other anatomical and demographic parameters using CBCTs for dental implant surgical planning.

Methods

The study included CBCT images of 76 consecutive patients with field-of-view 15 × 12 or 12 × 8cm. Reformatted cross-sectional CBCT slices were analyzed with regard to the thickness of the Schneiderian membrane designated by the medial and the lateral walls of the sinus, in three different standardized points of reference. Age, gender, and position of the measurement were evaluated as factors that could influence the dimensions of the anatomical structures, using univariate and multivariate random effects regression model.

Results

The mean thickness of the Schneiderian membrane was 1.60 ± 1.20 mm. The average thickness revealed now differentiation by age (p = 0.878), whereas gender seemed to influence the mean thickness (p = 0.010). Also, the thickness of the Schneiderian membrane increased from medial to distal (p = 0.060). The mean value of the angle designated by buccal and lingual walls of the sinus was 73.41 ± 6.89 °. The angle measurements revealed no correlation with age, but a tendency towards lower mean angles in females (2.5 ° on average, p = 0.097). According to the anatomical position of the measurement, a differentiation was also detected. No correlation between thickness of the Schneiderian membrane and the angle of the walls of the sinus was concluded (p = 0.662).

Conclusions

This study demonstrated that the thickness of the Schneiderian membrane and the width of the maxillary sinus can only be affected by gender and anatomical position, but not by the age of the patient.

Magnetic resonance imaging of a giant frontal hemorrhagic mucocele with intracranial extension in a cat

A 6-year-old domestic short-haired cat was presented with an acute onset of right cortical encephalopathy. Magnetic resonance imaging (MRI) performed 4 days after the onset of clinical signs revealed a lesion originating from the right frontal sinus with intracranial extension and compression of the right frontal lobe. The lesion was T1-weighted hypointense and T2-weighted and fluid-attenuated inversion recovery hyperintense. Signal voids within the lesion were observed on T2* images, consistent with hemorrhage. Peripheral ring enhancement was visible on postcontrast sequences. These features were consistent with a giant hemorrhagic mucocele. To the authors' knowledge, this is the first report of MRI characteristics of this lesion in a cat.

Mucocele After Orbital Fracture Repair Masquerading as Optic Neuritis

The authors report a patient of mucocele formation after orbital wall fracture repair masquerading as optic neuritis.A 38-year-old man with a history of medial orbital wall fracture repair with an alloplastic implant 10 years previously, presented with left visual disturbance and mild ocular pain with movement of the left eye of 3-day duration, and a relative afferent papillary defect in his left eye. He reported having cold symptoms 2 weeks before presentation. His symptoms were typical of retrobulbar optic neuritis. Under suspicion of optic neuritis, computed tomography and magnetic resonance imaging were performed and revealed a large cyst in the sphenoid sinus and ethmoid sinus, just behind the alloplastic implant, that was compressing the medial rectus muscle and optic nerve of the left eye. The patient underwent endoscopic marsupialization of the cyst. Subsequent histologic examinations revealed a cyst lined with ciliated pseudostratified columnar epithelium. The patient had an uncomplicated postoperative course and the visual disturbance resolved. For patients who present solely with optic neuropathy after orbital fracture repair, it is important to be vigilant of potentially rare cause, mucocele formation.

Extrasinonasal infiltrative process associated with a sinonasal fungus ball: does it mean invasive fungal sinusitis?

PURPOSE

Invasive fungal sinusitis (IFS) has rarely been reported to develop from non-IFS. The purpose of this study was to disclose the nature of the extrasinonasal infiltrative process in the presence of a sinonasal fungus ball (FB).

METHODS

We retrospectively reviewed the medical records, computed tomography, magnetic resonance images of 13 patients with sinonasal FB and the extrasinonasal infiltrative process. Based on histology and clinical course, we divided the extrasinonasal infiltrative process into IFS and the nonfungal inflammatory/infectious process (NFIP). The images were analyzed with particular attention to the presence of cervicofacial tissue infarction (CFTI).

RESULTS

Of the 13 patients, IFS was confirmed in only one, while the remaining 12 were diagnosed to have presumed NFIP. One patient with IFS died shortly after diagnosis. In contrast, all 12 patients with presumed NFIP, except one, survived during a mean follow-up of 17 months. FB was located in the maxillary sinus (n=4), sphenoid sinus (n=8), and both sinuses (n=1). Bone defect was found in five patients, of whom four had a defect in the sphenoid sinus. Various sites were involved in the extrasinonasal infiltrative process, including the orbit (n=10), intracranial cavity (n=9), and soft tissues of the face and neck (n=7). CFTI was recognized only in one patient with IFS.

CONCLUSION

In most cases, the extrasinonasal infiltrative process in the presence of sinonasal FB did not seem to be caused by IFS but probably by NFIP. In our study, there were more cases of invasive changes with the sphenoid than with the maxillary FB.

Comparison of hand and semiautomatic tracing methods for creating maxillofacial artificial organs using sequences of computed tomography (CT) and cone beam computed tomography (CBCT) images

INTRODUCTION

The aim of this study was to compare the paranasal sinus volumes obtained by manual and semiautomatic imaging software programs using both CT and CBCT imaging.

METHODS

121 computed tomography (CT) and 119 cone beam computed tomography (CBCT) examinations were selected from the databases of the authors' institutes. The Digital Imaging and Communications in Medicine (DICOM) images were imported into 3-dimensonal imaging software, in which hand mode and semiautomatic tracing methods were used to measure the volumes of both maxillary sinuses and the sphenoid sinus. The determined volumetric means were compared to previously published averages.

RESULTS

Isometric CBCT-based volume determination results were closer to the real volume conditions, whereas the non-isometric CT-based volume measurements defined coherently lower volumes. By comparing the 2 volume measurement modes, the values gained from hand mode were closer to the literature data. Furthermore, CBCT-based image measurement results corresponded to the known averages.

CONCLUSIONS

Our results suggest that CBCT images provide reliable volumetric information that can be depended on for artificial organ construction, and which may aid the guidance of the operator prior to or during the intervention.

Complications of sinusitis

BACKGROUND

Sinusitis is a common disorder associated with significant patient symptomatology that adversely affects quality of life. Sinusitis can cause further morbidity and mortality through its impact on comorbid disorders, progression of inflammation, and extension of infection.

OBJECTIVE

This review highlights common complications of acute bacterial rhinosinusitis (ABRS) and chronic rhinosinusitis (CRS).

RESULTS

ABRS is complicated by orbital infections, such as pre- or postseptal cellulitis, and by intracranial infections, including abscesses of the epidural and subdural spaces. CRS can contribute to asthma, sleep disordered breathing, and smell disorders. CRS can be complicated by development of allergic fungal rhinosinusitis or deformity of surrounding bony structures. Fungal complications contribute to morbidity and mortality.

CONCLUSION

Complications of ABRS, although relatively rare, can cause significant morbidity and mortality, and must be promptly recognized. CRS commonly complicates or drives comorbid diseases, which adversely impacts quality of life. Treatment of these complications often requires coordinated multidisciplinary care.

Differentiating Benign from Malignant Sinonasal Lesions: Feasibility of Diffusion Weighted MRI

Introduction  Appearance of nasal masses on routine CT and MRI are not pathognomonic. We utilized the apparent diffusion coefficient (ADC) value obtained from diffusion weighted image (DWI) to detect the differences in the microstructures of tumor and non-tumor tissues.

Objective  The objective of our study was to evaluate the diagnostic role of DWI and ADC values in differentiating between malignant and benign sinonasal lesions and its correlation with histopathological results as the reference standard.

Methods  Patients with nasal and / or paranasal mass underwent CT, MRI, and DWI before any surgical intervention. We used diagnostic sinonasal endoscopy and biopsy to confirm the diagnosis after MRI.

Results  When we used ADC value of (1.2 × 10–3 mm2/s) as a cut-off value for differentiating benign from malignant sinonasal lesions, we achieved 90% accuracy, 100% sensitivity, 88.4% specificity, 77.8% positive predictive value, and 100% negative predictive value. At this cut-off, benign lesions show statistically significant higher ADC value than malignant tumors.

Conclusion  DW MRI and ADC value calculation are promising quantitative methods helping to differentiate between malignant and benign sinonasal lesions. Thus, they are effective methods compared with other conventional methods with short imaging time thus it is recommended to be incorporated into routine evaluations.

The Age-Related Development of Maxillary Sinus in Children

INTRODUCTION

Paranasal sinuses are complex structures and show individual variation. Providing normative values for paranasal sinus size and their changes related to age could be helpful in evaluating the presence of some diseases related to sinonasal region. The purpose of the current study was to investigate the development of maxillary sinuses and evaluate the volume changes according to age and sex by using stereological and ellipsoidal formula methods after that to compare these approaches with each other in children.

MATERIALS AND METHODS

This retrospective volumetric computed tomography (CT) study was carried out on 361 individuals (180 females, 181 males) between 0 and 18 years old (10 females, 10 males in each group, only 14 age group includes 11 males) with no signs of sinus pathology volumetric estimations determined on CT images using point-counting approach of stereological methods and ellipsoid formula by using morphometric data.

RESULTS

Maxillary sinus volume measurements that were obtained using 2 methods were increased with age in both sexes until 16 years old. There was a significant correlation determined between 2 methods (ICC 0.894-1.000 for right and 0.862-0.999 for left maxillary sinus measurements). According to the sex, the right and left mean maxillary sinuses volumes were determined at 8.30 ± 5.19 and 8.57 ± 5.53 cm(3) in male and at 7.60 ± 4.57 and 7.99 ± 4.73 cm(3) in female by using ellipsoid formula respectively. By the stereological method these values were 8.28 ± 5.26, 8.44 ± 5.35 cm(3) and 7.64 ± 4.55, 7.85 ± 4.73 cm(3) respectively. There was no statistically significant difference between the volume of maxillary sinuses with sex and side using both methods.

CONCLUSIONS

This study presents the basic data for studies relative to the development of the maxillary sinus in children according to 2 methods. The current study demonstrated that the point-counting method and ellipsoid formula are both effective in determining volume estimation of maxillary sinuses and are well suited for CT studies.

Current Trends in Sinonasal Imaging

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

Imaging in Sinonasal Inflammatory Disease

While most patients with inflammatory rhinosinusitis are successfully diagnosed clinically, imaging is indicated in patients with recurrent or chronic sinusitis, atypical symptoms and complicated acute sinusitis. Non-enhanced high resolution, thin section computed tomography (CT) is the reference standard in evaluating such patients. It provides superb anatomical details and enables a fairly accurate diagnosis and delineation of the disease, addressing all concerns of the endoscopic surgeon prior to intervention. Contrast MR imaging is preferred for assessing intraorbital or intracranial complications. The radiologist must have a systematic approach to sinonasal CT and generate a clinically relevant report that impacts patient management.

Paranasal sinus opacification in headache sufferers: A population-based imaging study (the HUNT study-MRI)

Background

The association between headache and paranasal sinus disease is still unclear. Because of symptom overlap, the two conditions are not easily studied on the basis of symptoms alone. The aim of the present study was to investigate whether paranasal sinus opacification on magnetic resonance imaging (MRI) was associated with migraine, tension-type headache (TTH) or unclassified headache.

Methods

This was a cross-sectional study of 844 randomly selected participants (442 women, age range 50–65 years, mean age 57.7 years). Based on 14 headache questions, participants were allocated to four mutually exclusive groups: migraine, TTH, unclassified headache or headache free. On MRI, opacifications as mucosal thickening, polyps/retention cysts and fluid in the five paired sinuses were measured and recorded if ≥1 mm. For each participant, opacification thickness was summed for each sinus and, in addition, a total sum of all sinuses was calculated. Opacification in each sinus was compared between headache-free participants and the headache groups using non-parametric tests, and the total sum was compared by logistical regression.

Results

No significant association was found between paranasal sinus opacification and headache in general, nor when headache was differentiated into migraine, TTH and unclassified headache. This was also true in separate analyses of mucosal thickening and fluid and of opacification from each paranasal sinus.

Conclusion

Migraine, TTH and unclassified headache were found not to be associated with an increased degree of paranasal sinus opacification at MRI.

Magnetic Resonance Imaging of Acute Head and Neck Infections

This article discusses the use of MR imaging in various acute infectious diseases of the head and neck, with particular emphasis on situations where MR imaging provides additional information that can significantly impact treatment decisions and outcomes. MR imaging findings of various disease processes are discussed, based on the head and neck compartments from which they originate. Specifically, infectious entities of the orbit, paranasal sinuses, pharynx, oral cavity (including periodontal disease), salivary glands, temporal bone, and lymph nodes are described in detail.

Optimized imaging of the midface and orbits

A variety of imaging techniques are available for imaging the midface and orbits. This review article describes the different imaging techniques based on the recent literature and discusses their impact on clinical routine imaging. Imaging protocols are presented for different diseases and the different imaging modalities.

Paranasal sinus opacification at MRI in lower airway disease (the HUNT study-MRI)

The study builds on the concept of united airways, which describes the link between the upper and lower airways. Explorations of this concept have mainly related to asthma and less to chronic obstructive pulmonary disease (COPD). The aim of this study was to investigate paranasal sinus opacification at magnetic resonance imaging (MRI) in COPD, self-reported asthma and respiratory symptoms. In this cross-sectional study, 880 randomly selected participants in the Nord-Trøndelag health survey (HUNT) (mean age 57.7 years, range 50-66 years, 463 women) were investigated using MRI of the paranasal sinuses. Participants were allocated to four mutually exclusive groups: (1) COPD (n = 20), (2) asthma (n = 89), (3) respiratory symptoms (n = 199), and (4) reference group (n = 572). Paranasal sinus opacifications were categorised as mucosal thickening, polyps and retention cysts, and fluid. In each participant, measurements ≥1 mm from all sinuses were summed to give a total for each category of opacities. The sums for these three categories were further added together, and referred to as the total sum. Using the 75th percentile cut-off values, the likelihood of having paranasal sinus opacifications was more than six times higher in participants with COPD and twice as high in participants with asthma than among the reference group. Respiratory symptoms were only associated with mucosal thickening. The present study shows that paranasal sinus opacification is associated not only with asthma, but also with COPD and respiratory symptoms. This is in accordance with the united airways hypothesis, and should be kept in mind when handling patients with these conditions.

Imaging characteristics of sinonasal organized hematoma

BACKGROUND

Sinonasal organized hematoma is a rare benign disease that may be mistaken for malignancy.

PURPOSE

To define the imaging characteristics of sinonasal organized hematoma.

MATERIAL AND METHODS

We retrospectively reviewed computed tomography (CT) images of eight patients (4 male patients, 4 female patients; mean age, 40 years; range, 9-83 years) with pathologically proven sinonasal organized hematomas; magnetic resonance imaging (MRI) was performed in one patient among them. The following lesions characteristics were analyzed: size, shape, location, expansile nature, density, signal intensity, internal structure, enhancement pattern, and surrounding bony wall change.

RESULTS

The lesion sizes were in the range of 2-5.2 cm (mean, 3.55 cm), and the shapes were lobular, lumpy, or nodular. They were located in the nasal cavity (n = 1), maxillary sinuses (n = 2), or both nasal cavities and maxillary sinuses (n = 5). Expansile lesions with locally aggressive margins were observed in two cases. All lesions were hyperdense on precontrast CT scans; the smaller lesions showed even hyperdensity, whereas the larger lesions showed uneven density. The signal intensity was mixed on MRI, consisting of hemorrhage, fibrosis, and neovascularization. Papillary or frond-like enhancement was noted after contrast injection. All cases showed smooth erosion of the medial walls of the maxillary sinuses, and the epicenters were the secondary maxillary ostia. Two lesions showed erosion of the lateral walls of the maxillary sinuses and were expansile in nature. Non-hemorrhagic polyps accompanied the organized hematomas in three cases.

CONCLUSION

Although sinonasal organized hematoma can be mistaken for a malignant tumor, the following characteristic imaging findings facilitate the diagnosis of an organized hematoma: erosion of the bony sinus walls, markedly heterogeneous signal intensity, and papillary or frond-like enhancement.

Magnetic resonance imaging in sinonasal disease

Computed tomography (CT) is often the primary imaging modality for the evaluation of sinonasal disease. For some indications, magnetic resonance imaging (MRI) may provide additional information. There are established indications for using MRI in complicated sinonasal inflammatory disease, invasive fungal sinus disease, and sinonasal mass lesions. When MRI is used in the evaluation of sinonasal disease, it is usually used as a complementary modality in addition to CT. Magnetic resonance imaging in sinonasal disease can be used to further characterize the primary sinonasal disease process and to evaluate the extent of complications such as orbital or intracranial involvement. When MRI is used in sinonasal disease, it should be evaluated in the context of the clinical situation and CT imaging features. This will help radiologists provide a meaningful differential diagnosis to assist in clinical management.

Incidental findings in MRI of the paranasal sinuses in adults: a population-based study (HUNT MRI)

BACKGROUND

Diagnostic imaging of the head is used with increasing frequency, and often includes the paranasal sinuses, where incidental opacifications are found. To determine the clinical relevance of such findings can be challenging, and for the patient such incidental findings can give rise to concern if they are over-reported. Studies of incidental findings in the paranasal sinuses have been conducted mostly in patients referred for diagnostic imaging, hence the prevalence in the general population is not known. The purpose of this study was to determine the prevalence and size of incidental opacification in the paranasal sinuses in a non-selected adult population using magnetic resonance imaging (MRI) without medical indication, and to relate the results to sex and season.

METHODS

Randomly and independent of medical history, 982 participants (518 women) with a mean age of 58.5 years (range, 50-66) underwent MRI of the head as part of a large public health survey in Norway. The MRIs included 3D T1 weighted volume data and 2D axial T2 weighted image (WI). Opacifications, indicating mucosal thickenings, polyps, retention cysts, or fluid, were recorded if measuring more than 1 mm.

RESULTS

Opacifications were found in 66% of the participants. Mucosal thickenings were found in 49%, commonly in the maxillary sinuses (29%) where 25% had opacifications that were less than 4 mm in size. Other opacifications occurred in the anterior ethmoid (23%), posterior ethmoid (21%), frontal sinus (9%), and sphenoid (8%). Polyps and retention cysts were also found mainly in the maxillary sinuses in 32%. Fluid was observed in 6% of the MRIs. Mucosal thickening was observed more frequently in men than in women (P <0.05). No seasonal variation was found.

CONCLUSIONS

In this large non-selected sample, incidental opacification in the paranasal sinuses was seen in two out of three participants, and mucosal thickening was seen in one out of two. Fluid was rare. Knowledge of incidental opacification is important because it can affect clinical practice.

MRI findings of otic and sinus barotrauma in patients with carbon monoxide poisoning during hyperbaric oxygen therapy

BACKGROUND AND PURPOSE

To study the MRI findings of otic and sinus barotrauma in patients with carbon monoxide(CO) poisoning during hyperbaric oxygen (HBO) therapy and examine the discrepancies of otic and sinus abnormalities on MRI between barotrauma and acute otitis media with effusion.

MATERIALS AND METHODS

Eighty patients with CO-poisoning diagnosed with otic and sinus barotrauma after HBO therapy were recruited. Brain MRI was performed to predict delayed encephalopathy. Over the same period, 88 patients with acute otitis media with effusion on MRI served as control. The abnormalities of the middle ear and paranasal sinuses on MRI were noted and were compared between groups. Nine patients with barotrauma were followed up by MRI.

RESULTS

In the barotrauma group, 92.5% of patients had bilateral middle ear abnormalities on MRI, and 60% of patients had both middle ear cavity and mastoid cavity abnormalities on MRI in both ears. Both rates were higher than those in the control group (p = 0.000). In the two groups, most abnormalities on MRI were observed in the mastoid cavity. The rate of sinus abnormalities of barotrauma was 66.3%, which was higher than the 50% in the control group (p = 0.033). In the nine patients with barotrauma followed up by MRI, the otic barotrauma and sinus abnormalities had worsened in 2 patients and 5 patients, respectively.

CONCLUSION

MRI is able to depict the abnormalities of otic and sinus barotrauma in patients with CO-poisoning during HBO therapy and to differentiate these from acute otitis media with effusion.

Sinus imaging for diagnosis of chronic rhinosinusitis in children

Chronic rhinosinusitis (CRS) is a relatively common disease in children but is often overlooked because at times the clinical symptoms are subtle and nonspecific. This makes imaging very important in the diagnosis. Among the different techniques, plain radiography has limited utility,whereas CT scan and MRI have a major role in evaluating the modifications caused by the disease. In particular, a CT scan provides higher resolution of bone and soft tissue and removes the overlapping structures that are present in conventional radiography. CT is recommended in isolated sphenoid sinusitis, is essential in diagnosing fungal sinusitis, and is the technique of choice when orbital complications are suspected. MRI allows investigation of not only the morphology of structures, but their intrinsic biophysical and biochemical properties, such as water content, cellular density, lipid or blood product deposits, and fibrosis. MRI allows better soft tissue differentiation and high spatial resolution images depicting fine details. When indicated, MRI with contrast gadolinium-based agents may better characterize the local disease extension or its diffusion beyond paranasal and nasal cavities and has excellent contrast resolution. A combination of CT and MRI is useful in cases of diagnostic difficulties,especially when complications are involved.

Diagnosis of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a rather common disease in children, but its symptoms are often subtle and non-specific and this may result in overlooking a correct diagnosis. In turn, a missed diagnosis of CRS prevents a correct management to be performed and is associated with uneffective investigations and improper treatments. Actually, when CRS symptoms, which are mainly nasal congestion and obstruction, nasal discharge, facial pain, cough, and halitosis, are correctly assessed, the clinical diagnosis of CRS may be achieved, and confirmation may be obtained by imaging criteria or nasal fibroendoscopy. In imaging, computed tomography (CT) is the first choice technique for the evaluation of CRS and is able to provide an anatomic road map when surgery is required. Magnetic resonance imaging (MRI) of the sinuses, orbits, and brain should be performed whenever extensive or multiple complications of sinusitis are suspected. Also for middle ear disorders, CT is the first choice because it detects opacification of the middle ear cavity and mastoid cells, presence of fluids or debris, and allows the ossicular chain and the cortical bone of the mastoid to be evaluated. Another important diagnostic issue is the need to look for disorders that are frequently associated with CRS, such as obstructive sleep apnea syndrome (OSAS), that has some recognized risk factors in adenotonsillar hypertrophy, craniofacial anomalies, obesity, and neuromuscular disorders. Other associated disorders requiring investigation are recurrent or persistent otitis media and difficult asthma.

Multiparametric MR imaging of sinonasal diseases: time-signal intensity curve- and apparent diffusion coefficient-based differentiation between benign and malignant lesions

BACKGROUND AND PURPOSE

The sinonasal region is a platform for a broad spectrum of benign and malignant diseases, and image-based differentiation between benign and malignant diseases in this area is often difficult. Here, we evaluated multiparametric MR imaging with combined use of TICs and ADCs for the differentiation between benign and malignant sinonasal tumors and tumorlike diseases.

MATERIALS AND METHODS

TICs obtained from dynamic contrast-enhanced MR imaging and ADCs were analyzed on a lesion-by-lesion (overall TIC and ADC) and pixel-by-pixel (TIC and ADC mapping) basis in patients with benign (n = 21) or malignant (n = 23) sinonasal tumors and tumorlike diseases. The TICs were semiautomatically classified into 5 distinctive patterns (flat, slow uptake, rapid uptake with low washout ratio, rapid uptake with high washout ratio, and miscellaneous). ADCs were determined by using b-values of 500 and 1000 s/mm(2).

RESULTS

Malignant sinonasal tumors had small (<25%) areas of the type 1 flat TIC profile as determined by pixel-by-pixel TIC analysis and large (≥50%) areas of low or extremely low ADCs (≤1.2 × 10(-3) mm(2/)s) as determined by ADC mapping. Consequently, stepwise classification on the basis of TICs and ADCs successfully (at 100% accuracy) discriminated malignant from benign sinonasal diseases in the present patient cohort.

CONCLUSIONS

Multiparametric MR imaging by using TICs and ADCs may help differentiate benign and malignant sinonasal diseases.

Fungus ball within a mucocele of the sphenoid sinus and infratemporal fossa: case report with radiological findings

OBJECTIVE

We report an extremely rare case of a fungus ball within a mucocele of the sphenoid sinus and infratemporal fossa.

CASE REPORT

A 62-year-old woman was referred for evaluation of a mass lesion in the left sphenoid sinus and infratemporal fossa. Endoscopic examination of the nasal cavity was unremarkable. Computed tomography showed a non-enhancing, expansile mass with calcifications in the sphenoid and infratemporal fossa; T2-weighted magnetic resonance imaging revealed marked hypointense signals within the sphenoid sinus mass, with an intermediate signal intensity. A presumptive diagnosis of a mucocele was made. During surgery, a profuse amount of yellow fluid was drained from the mucocele. Clay-like material was noted within the mucocele, corresponding to the hypointense magnetic resonance imaging signals; this was identified as aspergillus on histopathological examination. Radiological findings for a fungus ball within a mucocele can be similar to those for allergic fungal sinusitis, which shows mixed low and high attenuation on computed tomography and low-signal intensity on T2-weighted magnetic resonance imaging, within an expansile, cystic lesion.

CONCLUSION

Although an association between a fungus ball and a mucocele is rare in the paranasal sinuses, this disease entity should be considered in the differential diagnosis of expansile, cystic sinus lesions.