Radiographic density profiles link frontal and anterior ethmoid sinuses behavior in chronic rhinosinusitis

Value of MRI signal intensity in evaluation of allergic fungal rhinosinusitis compared with CT Hounsfield units: Retrospective study

"Allergic fungal sinusitis (AFS)" is typically diagnosed using radiologic images like computed tomography (CT) scans and magnetic resonance imaging (MRI), with the "Hounsfield unit (HU)" in CT scans and T2-weighted images (T2WI) in MRI serving as reliable objective parameters. However, diagnosing AFS might be difficult because of possible signal changes and densities caused by variations in the secretion concentration in the sinus. Few studies have compared the diagnostic performance of MRI and CT scans. This study aimed to investigate the value of MRI signal intensity in evaluating AFS compared with CT HUs. This retrospective study included 111 patients with pathologically confirmed AFS who underwent CT imaging followed by MRI evaluation at King Saud Medical City, Riyadh, Saudi Arabia, from January 2012 to December 2022. Radiographic densities of sinus opacities on CT scan, including the mean HU values, and MRI findings, including signal voids on T1-weighted images and T2WI, were gathered and analyzed. To determine the efficacy of these radiographic characteristics in predicting the disease and the best cutoff value, we employed receiver operator characteristic curves. The mean age was 31.9 ± 15.6 years, and most patients were 74 females (66.7%). The main symptom was nasal obstruction in 73 patients (65.8%). In comparison, between HU and signal void on T2WI, there was moderate predictive performance [area under the curve: 0.856, P = .001]. An ideal HU cutoff value of 69.50 HU was obtained with a sensitivity of 100% and a specificity of 44.7%. However, the receiver operator characteristic for T1-weighted images could not be plotted, as no signal was avoided to predict AFS and it was not statistically significant (area under the curve: 0.566; P = .287). The study found a CT HU of 69.5 can predict MRI T2WI signal values with a void signal, aiding in diagnostic workup and evaluation for AFS.

Radiologic sinus inflammation and symptoms of chronic rhinosinusitis in a population-based sample

BACKGROUND

Chronic rhinosinusitis (CRS) epidemiology has been largely studied using symptom-based case definitions, without assessment of objective sinus findings.

OBJECTIVE

To describe radiologic sinus opacification and the prevalence of CRS, defined by the co-occurrence of symptoms and sinus opacification, in a general population-based sample.

METHODS

We collected questionnaires and sinus CT scans from 646 participants selected from a source population of 200 769 primary care patients. Symptom status (CRS_S ) was based on guideline criteria, and objective radiologic inflammation (CRS_O ) was based on the Lund-Mackay (L-M) score using multiple L-M thresholds for positivity. Participants with symptoms and radiologic inflammation were classified as CRS_S+O . We performed negative binomial regression to assess factors associated with L-M score and logistic regression to evaluate factors associated with CRS_S+O . Using weighted analysis, we calculated estimates for the source population.

RESULTS

The proportion of women with L-M scores ≥ 3, 4, or 6 (CRS_O ) was 11.1%, 9.9%, and 5.7%, respectively, and 16.1%, 14.6%, and 8.7% among men. The respective proportion with CRS_S+O was 1.7%, 1.6%, and 0.45% among women and 8.8%, 7.5%, and 3.6% among men. Men had higher odds of CRS_S+O compared to women. A greater proportion of men (vs women) had any opacification in the frontal, anterior ethmoid, and sphenoid sinuses.

CONCLUSION

In a general population-based sample in Pennsylvania, sinus opacification was more common among men than in women and opacification occurred in different locations by sex. Male sex, migraine headache, and prior sinus surgery were associated with higher odds of CRS_S+O .

Outcomes of chronic frontal sinusitis treated with ethmoidectomy: a prospective study

BACKGROUND

In medically refractory chronic frontal sinusitis, ethmoidectomy without instrumentation of the frontal ostium may resolve frontal disease. Our aim was to determine the efficacy of ethmoidectomy alone for the treatment of chronic frontal sinusitis.

METHODS

Adults with chronic rhinosinusitis prospectively enrolled in a multicenter study who demonstrated frontal sinusitis on computed tomography were divided into 2 groups: (1) endoscopic sinus surgery (ESS) incorporating ethmoidectomy, but excluding frontal sinusotomy; and (2) ESS incorporating frontal sinusotomy. The primary outcome was improvement in 22-item Sino-Nasal Outcome Test (SNOT-22) scores. Secondary outcomes included endoscopic scores and use of corticosteroids and antibiotics.

RESULTS

A total of 196 cases undergoing frontal sinusotomy and 30 cases treated with ethmoidectomy without frontal sinusotomy were analyzed and were comparable demographically. The prevalence of nasal polyps, previous ESS, asthma, and aspirin intolerance was more common in the frontal sinusotomy group (p < 0.050). Preoperative endoscopy and computed tomography scores were higher in the frontal sinusotomy group (p ≤ 0.001). Postoperatively, both groups showed comparable SNOT-22 scores with worse endoscopy scores in the frontal sinusotomy group (p = 0.038). Postoperative improvement in SNOT-22 total and subdomain scores was comparable between groups. Nasal endoscopy scores improved to a greater degree in the frontal sinusotomy group (p = 0.023). Duration of postoperative topical steroid use was higher in the frontal sinusotomy group (p = 0.007). Revision surgery was needed in 2.6% of frontal sinusotomy patients and 0% of patients without frontal sinusotomy.

CONCLUSION

The treatment of chronic frontal sinusitis through ethmoidectomy is a potential alternative to frontal sinusotomy achieving similar quality of life (QOL) improvements in patients manifesting less severe sinus disease.

Objective radiographic density measurements of sinus opacities are not strong predictors of noninvasive fungal disease

BACKGROUND

High-density paranasal sinus opacities are often deemed consistent with fungal elements. No studies of objective quantitative radiographic density measures have been performed to support this assertion.

METHODS

A consecutive series of 120 patients with chronic rhinosinusitis who underwent maxillary antrostomy with microbiological evaluation of contents within 60 days of sinus computed tomography scanning was investigated. Radiographic density characteristics of opacities in cultured maxillary sinuses (minimum, maximum, average, and standard deviation of Hounsfield units [HUstd]) were recorded. Receiver operator characteristic (ROC) curves were used to analyze the accuracy of radiographic characteristics in predicting fungal opacities.

RESULTS

Of 133 maxillary sinus opacities, 22 were ultimately consistent with noninvasive fungal disease: 11 allergic fungal rhinosinusitis and 11 fungal balls. Fungal balls had higher-density components and were more heterogeneous and allergic fungal mucin was generally more radiodense. These findings were reflected by statistically significant ROC curves for maximum HU (p = 0.019) and HUstd (p = 0.023) for fungal balls and for average HU (p = 0.002) for allergic fungal mucin. A maximum HU cutoff of 334.0 detected fungal balls with 90.9% sensitivity and 72.7% specificity. An average HU cutoff of 42.9 HU detected allergic fungal mucin with 100% sensitivity and 46.3% specificity, although specificity improved to 73.2% with inclusion of nasal polyposis as a second requirement.

CONCLUSION

Higher average HU more accurately predicts allergic fungal mucin whereas heterogeneity/high-density components more accurately predict fungal balls. No objective radiographic density measure, in isolation, is both sensitive and specific in predicting noninvasive fungal sinusitis.