Radiation dose reduction and image quality in pediatric paranasal sinus CT: with automatic tube current modulation and iterative reconstruction technique.

Our objective is to evaluate radiation dose and image quality in pediatric paranasal sinus computed tomography (CT) with automatic tube current modulation (ATCM) and sinogram-affirmed iterative reconstruction algorithm (SAFIRE). CT scans from 80 patients were divided into two groups: Group A [80 kVp, pitch 1.5, 40 mAs, the filtered back projection (FBP) algorithm] and Group B (70 kVp, pitch 3, ATCM with reference at 40 mAs, SAFIRE strengths 1-5). We have evaluated image quality and radiation dose. Group B demonstrated significantly lower volume computed tomography dose index, dose-length product, and effective dose than Group A (0.13 ± 0.03 vs. 1.57 ± 0.01 mGy, 2.27 ± 0.82 vs. 19.88 ± 2.01 mGy·cm, and 0.0081 ± 0.0017 vs. 0.079 ± 0.013 mSv, respectively; P < .001). Increasing SAFIRE strengths correlated with noise reduction and SNR enhancement. Group B's noise and SNRsoft at SAFIRE strength 5 were comparable with Group A. Images reconstructed with SAFIRE strength 5 in Group B exhibit comparable image quality with FBP in Group A.

Sinonasal Anatomic Variations in the Adult Population: CT Examination of 1200 Patients.

BACKGROUND: The nasal cavity and paranasal sinuses are one of the most frequently anatomically varied regions. Their size and shape vary from person to person, and ethnic origin may have a role in this variety. Recognizing this variations is so important for ear nose throat (ENT) specialists because they predispose to sinonasal pathologies and affect the complication rate and success of endoscopic sinus surgery. AIM: This study aimed to determine the frequency of sinonasal anatomic variations on paranasal sinus computed tomography (CT) in the Turkish population. METHODS: Patients who had undergone paranasal sinus CT with any complaints between 2013 and 2020 and aged over 18 years were included in the study. A total of 1209 patients who had undergone paranasal sinus CT were examined for coronal, axial, and sagittal plans retrospectively by two ENT professionals, and anatomical variations were evaluated. To assign the frequency of anatomic variations in a healthy population, patients who had previously undergone paranasal sinus and nasal surgery, who had nasal polyposis, and for whom CT evaluation was not possible due to intense sinusitis were excluded from the study. RESULTS: Among 1209 patients, 644 were male and 565 were female. The mean age of the patients was 33.7 years. The most common sinonasal anatomical variations were nasal septal deviation and agger nasi cells, while the least common variation is the supreme turbinate. No variation was found in 48 (3.9%) CTs. CONCLUSION: Almost all patients had at least one sinonasal anatomical variation. These variations should be known by the professionals who have interest in sinonasal disease and surgery.

[Analysis of imaging features of rare tumors in nasal cavity and paranasal sinus].

Objective:To explore the imaging features of rare tumors of nasal cavity and sinuses, and to improve the understanding of these diseases, thereby aiding clinical diagnosis and treatment. Methods:The CT and MRI findings of 79 cases of rare neoplasm of nasal cavity and sinuses confirmed by pathology were retrospectively analyzed, and the imaging features were summarized. Results:Among the 79 cases, there were 16 cases of neuroendocrine carcinoma, most showing expansive and infiltrative bone destruction without hyperosteogeny and sclerosis. The sphenoid sinus exhibited a "pigeon" shape. In 28 cases of malignant melanoma, MRI signals were diverse, typical signals were rare, but mixed signals were more common. In 12 cases of rhabdomyosarcoma, MRI enhancement mostly showed "grape-like" enhancement and partial ring enhancement; There were 10 cases of olfactory neuroblastoma, the lesions were consistent with the distribution area of olfactory mucosa, most of them were lobulated, marginal nodules, and "flower ring" enhancement, and 2 cases grew across intracranial and external, with multiple cystic lesions and surrounding flaky edema bands. In 5 cases of solitary fibrous tumor, Benign tumors had regular shape and uniform density, while malignant tumors had irregular shape and uneven density, The enhancement was obviously uneven and showed a "pattern" change. There were 2 cases of sarcomatoid carcinoma, both with lobed appearance, uneven density, lamellar low-density shadow, and osteolytic bone destruction. In 4 cases of schwannoma, the enhancement showed obvious inhomogeneous enhancement. One case showed cystic necrosis, one case showed calcification, and the surrounding structure was compressed without damage. There was 1 case of neurofibroma, with many cystic components, low signal separation and compartmentalized enhancement. One case of paraganglioma showed moderate enhancement in the arterial phase and progressive enhancement in the venous phase, accompanied by significant swelling bone destruction. Conclusion:Rare tumors of nasal cavity and paranasal sinuses have distinctive imaging features. CT and MRI can effectively show the extent of the lesions and the degree of infiltration into adjacent tissues and organs, which is helpful for early clinical diagnosis and staging. However, definitive diagnosis still depends on pathology and immunohistochemistry.

Diagnostic accuracy of double density sign on CT scan of para-nasal sinuses for fungal sinusitis taking microbiology culture as gold standard.

Objectives: To compare double-density sign on non-contrast computed tomography scan of paranasal sinuses with fungal sinusitis on histopathology. METHODS: This prospective study was conducted at the Shifa International Hospital, Islamabad, Pakistan, from July 1, 2021, to June 30, 2023, and comprised patients of either gender aged 20-60 years who were set to undergo functional endoscopic sinus surgery. Demographic characteristics and non-contrast computed tomography scan findings were recorded preoperatively, while microbiological and histopathology results were recorded post-operatively. The microbiological finding was taken as the gold standard. Data was analysed using SPSS 23. RESULTS: Of the 201 patients, 123(61.2%) were males and 78(38.8%) were females. The overall mean age was 41.62±8.52 years. The diagnostic accuracy of a double-density sign on computed tomography scan showed sensitivity 90%, specificity 90.8%, positive predictive value 84%, and negative predictive value 94.4%. CONCLUSIONS: A higher rate of sensitivity and specificity indicated that non-contrast computed tomography scan was an effective modality that could be used for the diagnosis of fungal sinusitis.

Computed Tomography Signs of Sinonasal Inflammation in Patients with Acute Dacryocystitis.

BACKGROUND: Nasal and paranasal sinus abnormalities may be related to nasolacrimal duct obstructive disease but are strongly debated. Data of acute disease stage are lacking. OBJECTIVE: The purpose of this study was to determine if there are correlations between radiologic signs of sinus inflammation and acute dacryocystitis (AD). METHODS: This cross-sectional controlled study was conducted at Wenzhou, Zhejiang Province, China from February 2021 to November 2023. Forty-four consecutive patients with AD and 50 consecutive patients with orbital tumors (the control group), who completed preoperative computed tomography scans, were enrolled to evaluate the extent of their inflammatory sinonasal disease by the modified Lund-Mackay score system. RESULTS: The inflammation signs of the paranasal sinuses (total mean sinus scores, 95% CI [0.00, 2.00]; P < 0.001), namely the anterior ethmoid sinus(95% CI [0.00, 1.00]; P < 0.001), the posterior ethmoid sinus(95% CI [0.00, 0.00]; P = 0.003), the frontal sinus (95% CI [0.00, 0.00]; P = 0.02), and the ostiomeatal complex (P < 0.001) were more extensive in patients with AD when compared with the controls. The disease course was negatively correlated with the anterior ethmoid (P = 0.03) and frontal scores (P = 0.01). The symptom of eyelid swelling was positively correlated with the anterior ethmoid (P = 0.03), ostiomeatal complex (P = 0.004), and total sinus scores (P = 0.005). CONCLUSION: Inflammatory sinus disease was found to be more frequent in patients with AD, which was gradually alleviated with the prolongation of the disease course. The mutual spread of inflammation particularly in the acute course may play an important role in lacrimal duct obstructive disease.

Three-Dimensional Segmentation of Equine Paranasal Sinuses in Multidetector Computed Tomography Datasets: Preliminary Morphometric Assessment Assisted with Clustering Analysis.

The paranasal sinuses, a bilaterally symmetrical system of eight air-filled cavities, represent one of the most complex parts of the equine body. This study aimed to extract morphometric measures from computed tomography (CT) images of the equine head and to implement a clustering analysis for the computer-aided identification of age-related variations. Heads of 18 cadaver horses, aged 2-25 years, were CT-imaged and segmented to extract their volume, surface area, and relative density from the frontal sinus (FS), dorsal conchal sinus (DCS), ventral conchal sinus (VCS), rostral maxillary sinus (RMS), caudal maxillary sinus (CMS), sphenoid sinus (SS), palatine sinus (PS), and middle conchal sinus (MCS). Data were grouped into young, middle-aged, and old horse groups and clustered using the K-means clustering algorithm. Morphometric measurements varied according to the sinus position and age of the horses but not the body side. The volume and surface area of the VCS, RMS, and CMS increased with the age of the horses. With accuracy values of 0.72 for RMS, 0.67 for CMS, and 0.31 for VCS, the possibility of the age-related clustering of CT-based 3D images of equine paranasal sinuses was confirmed for RMS and CMS but disproved for VCS.

Nasal endoscopy: What have we been missing?

Despite the widespread adoption of nasal endoscopy (NE) in the evaluation of sinonasal disease, its diagnostic potential may still be underutilized. Developments in endoscopic technology have led to significant improvements in video quality and maneuverability. However, there is concern that NE continues to be used primarily for the identification of gross pathology, with relative neglect of more subtle findings such as surface features of inflammation and mucus. With fewer technical limitations to perceive these abnormalities, there is potential to greatly improve the diagnostic value of NE. The reader is herein asked to consider several important visual nuances encountered during NE, with the hope that this engenders an appreciation of the versatility of NE as a diagnostic tool.

Indocyanine green fluorescence visualizes landmark arteries for endoscopic sinus and skull base surgery.

OBJECTIVE: Landmark arteries during endoscopic sinus surgery are currently identified on the basis of anatomy, CT imaging and navigation, and Doppler flowmetry. However, the advantage of intraoperative fluorescence imaging during endoscopic sinus surgery has not been demonstrated. This study aimed to investigate whether Indocyanine Green (ICG) is useful for visualizing landmark arteries during endoscopic sinus and skull base surgery. METHODS: Eight patients who underwent endoscopic sinus and pituitary surgeries and consented to study participation were included. After planned procedures were performed as usual, landmark arteries were examined by ICG endoscope. Recorded video and preoperative CT images were analyzed for identification of five landmark arteries: anterior ethmoidal artery (AEA), posterior ethmoidal artery (PEA), internal carotid artery (ICA), sphenopalatine artery (SPA), and postnasal artery (PNA). Identification of arteries was evaluated three grades: identifiable, locatable, unrecognizable. RESULTS: Eight patients and eleven sides were evaluated. The ICG dose was 2.5 mg/body and a single shot was sufficient for evaluation. 100 % of AEA was identified (9/9 sides), 86 % of PNA (6/7 sides), 56 % of ICA (5/9 sides), and 25 % of PEA and SPA (2/8 sides). CONCLUSION: ICG could visualize landmark arteries, even thin arteries like AEA, during endoscopic sinus and skull base surgeries. Visualization was affected by thickness of bone or soft tissue above arteries, blood clots, sensitivity setting, and angle and distance of near-infrared light irradiation. ICG visualization of landmark arteries may help avoid vascular injuries during endoscopic sinus and skull base surgeries, particularly of AEA, PNA and ICA.

Evaluation of sinonasal involvement in patients with asthma and chronic obstructive pulmonary disease.

Background: Asthma and chronic obstructive pulmonary disease (COPD) are the most common obstructive diseases. Based on the similarities, we aimed to evaluate sinonasal symptoms in patients with asthma or COPD, and compare the two diseases with regard to upper-airway involvement. Methods: Patients with asthma or with COPD who were followed up at Ankara University Immunology and Allergy or Chest Diseases Departments were included in the study. The participants went through pulmonary function tests, skin-prick tests, and disease severity assessment of either disease. Nasal endoscopic evaluations of all the patients were performed in the Department of Otorhinolaryngology. Lund-Mackay scoring was performed on the computed tomography of the paranasal sinus. Chronic rinosinusitis (CRS) diagnosis was made as recent guidelines. Results: A total of 112 subjects (number of women/men: n = 67/45; median age, 49 years [The range for IQR was 22 years]) were included in the study. Fifty-five patients had asthma, 33 had COPD, and 24 were healthy controls. Nasal symptoms were more frequent in the patients with asthma (patients with asthma, n = 52 [98%]; patients with COPD, n = 17 [52%]; controls, n = 9 [38%]) (p < 0.001). The median (IQR) 22-item Sino-Nasal Outcome Test (SNOT-22) questionnaire score was higher in the patients with asthma (33 [20-50]) than in the patients with COPD (8 [1.5-18.7]) and the control group (3.5 [0-18.7]) (p < 0.01). Patients with asthma had significantly higher prevalence rates of rhinosinusitis than did those in the COPD and the control groups (36%, 15.6%, 8.3%, respectively; p < 0.01). The SNOT-22 optimal cutoff score was calculated as ≥11 to detect the score limit for CRS prediction with the best sensitivity and specificity. Conclusion: As a result, patients with both asthma and COPD may have upper-airway symptoms. CRS, was primarily seen in the patients with asthma. Accordingly, SNOT-22 scores were higher in the patients with asthma than in those in the COPD and the control groups. A referral to the Ear Nose Throat department for further evaluation with nasal endoscopy and computed tomography of the paranasal may be required in a subgroup of patients.

Multiple instance learning for eosinophil quantification of sinonasal histopathology images: A hierarchical determination on whole slide images.

KEY POINTS: We proposed a hierarchical framework including an unsupervised candidate image selection and a weakly supervised patch image detection based on multiple instance learning (MIL) to effectively estimate eosinophil quantities in tissue samples from whole slide images. MIL is an innovative approach that can help deal with the variability in cell distribution detection and enable automated eosinophil quantification from sinonasal histopathological images with a high degree of accuracy. The study lays the foundation for further research and development in the field of automated histopathological image analysis, and validation on more extensive and diverse datasets will contribute to real-world application.

An endoscopic chisel: intraoperative imaging carves 3D anatomical models.

PURPOSE: Preoperative imaging plays a pivotal role in sinus surgery where CTs offer patient-specific insights of complex anatomy, enabling real-time intraoperative navigation to complement endoscopy imaging. However, surgery elicits anatomical changes not represented in the preoperative model, generating an inaccurate basis for navigation during surgery progression. METHODS: We propose a first vision-based approach to update the preoperative 3D anatomical model leveraging intraoperative endoscopic video for navigated sinus surgery where relative camera poses are known. We rely on comparisons of intraoperative monocular depth estimates and preoperative depth renders to identify modified regions. The new depths are integrated in these regions through volumetric fusion in a truncated signed distance function representation to generate an intraoperative 3D model that reflects tissue manipulation RESULTS: We quantitatively evaluate our approach by sequentially updating models for a five-step surgical progression in an ex vivo specimen. We compute the error between correspondences from the updated model and ground-truth intraoperative CT in the region of anatomical modification. The resulting models show a decrease in error during surgical progression as opposed to increasing when no update is employed. CONCLUSION: Our findings suggest that preoperative 3D anatomical models can be updated using intraoperative endoscopy video in navigated sinus surgery. Future work will investigate improvements to monocular depth estimation as well as removing the need for external navigation systems. The resulting ability to continuously update the patient model may provide surgeons with a more precise understanding of the current anatomical state and paves the way toward a digital twin paradigm for sinus surgery.

Enfrentamiento diagnóstico de la rinosinusitis aguda en pacientes adultos ambulatorios / Diagnostic Approach of acute rhinosinusitis in adults outpatients

Acute rhinosinusitis is a common condition, mainly of viral etiology and self-limiting course. There is coexistence of microbiological agents that favor bacterial superinfection. Therefore, it is necessary to know evidence that supports diagnostic approach in adults out- patients. Having reviewed the evidence, we mention the isolated symptoms and signs have such a low performance to guide the diagnostic approach, some with statistical evidence such as hemifacial pain, colored nasal discharge and radiographic alterations suggestive of rhinosinusitis. Also, it is possible to improve clinical performance by combining suggestive findings. The imaging study has little evidence that supports them, because non-specific and non-concordant findings. Finally, empirical management with antibiotics does not statistically or clinically modify the evolution of an acute non-complicated condition.

La rinosinusitis aguda es una condición frecuente, principalmente de etiología viral y de curso autolimitado. Existe coexistencia de agentes microbiológicos que favorece la sobreinfección bacteriana. Por ello, es necesario conocer la evidencia que dirige el enfrentamiento diagnóstico en pacientes adultos ambulatorios. Habiéndose revisado la evidencia, mencionamos que los síntomas y signos aislados poseen bajo rendimiento para guiar el proceso diagnóstico, destacando algunos con mejores atributos diagnósticos, pero de significancia estadística bastante discreta, como lo son el dolor hemifacial, la descarga nasal coloreada y alteraciones de la radiografía sugerentes de rinosinusitis. También, que se puede mejorar discretamente el rendimiento clínico combinando algunos de estos hallazgos sugerentes. El estudio imagenológico posee poca evidencia que lo respalde, dado la presencia de hallazgos inespecíficos o no concordantes, inclusive en pacientes asintomáticos. Finalmente, respecto de manejo empírico con antibióticos, destaca que su uso no modifica estadística ni clínicamente la evolución de un cuadro agudo no complicado.

Sinonasal manifestations of granulomatosis with polyangiitis: A retrospective analysis.

OBJECTIVE: This study aimed to examine the characteristics of nasal and imaging findings of sinonasal lesions in granulomatosis with polyangiitis (GPA) patients and how these lesions change over time in both the active and remission phases of the disease. METHODS: We retrospectively reviewed GPA patients with sinonasal lesions who were followed up at our department between January 2005 and December 2020. The following data were collected: age, sex, symptoms at initial presentation, anti-neutrophil cytoplasmic antibody (ANCA) type, and histopathological, nasal (initial and follow-up), and imaging (initial and follow-up) findings. RESULTS: This study included 17 patients with GPA aged 30 to 79 years. Computed tomography (CT) of the sinuses showed mucosal thickening in 16 patients, bone thickening in 12, bone destruction in 4, and an orbital invasion mass in 3 at the time of diagnosis. After initiating treatment, mucosal thickening of the sinuses improved in 3 of 16 patients and remained unchanged in 13. Bone thickening at the time of diagnosis remained unchanged in 10 of 12 patients and worsened in 2; 1 patient displayed newly developed bone thickening. Destructive nasal findings on CT were positive for proteinase 3-ANCA. CONCLUSIONS: Our study revealed that mucosal thickening, bone thickening, bone destruction, and orbital invasion mass were major CT findings in patients with GPA. Intranasal findings such as granulations, crusting, and necrosis were seen in the active phase; moreover, saddle nose, loss of turbinate, and nasal septal perforation were subsequently seen in the course of the disease. Sinonasal findings of GPA vary depending on the disease stage and period.

The association between sinonasal anatomical variants and the laterality of orbital complications in pediatric acute rhinosinusitis.

INTRODUCTION: As the role of sinonasal anatomical variants as predisposing factors in determining the lateralization of acute rhinosinusitis-related orbital complications (ARS-OC) in pediatrics remains a topic of debate, this study further explores the potential association between anatomical variations and ARS-OC. METHODS: A retrospective study was conducted on children who had been admitted with ARS-OC using medical records and sinus CT scans to compare anatomical differences between the affected and contralateral sides. This study aimed to identify bony anatomical disparities that may impact OC laterality secondary to ARS. The anatomical features examined included septal deviation, concha bullosa, lamina papyracea dehiscence (LPD), and uncinate process abnormalities. RESULTS: The CT scans of 57 pediatric patients (114 sides) were reviewed. Our results indicated that bony anatomical variations were associated with ARS-OC laterality (63 % vs. 37 %, P = 0.006), yielding an odds ratio of 2.91. Additionally, our study revealed a significant association between ipsilateral LPD with the increased risk of ARS-OC (39 % vs. 1.8 %, P < 0.05), with an odds ratio of 34.3 compared to the opposite side. CONCLUSIONS: LPD might play a role in the pathophysiology of pediatric ARS-OC, as it is associated with a significantly higher risk of affecting the ipsilateral side. Further research is necessary to determine whether LPD is a causative factor or a result of ARS.

Severe Hypoplasia of Paranasal Sinuses and Turbinates.

This case report describes a patient in their 40s with a history of bronchiectasis, azoospermia, and epididymal cysts who presented with bilateral nasal obstruction.

Dental findings frequently overlooked in sinus computed tomography reports.

OBJECTIVES: Computed tomography (CT) and cone beam computed tomography (CBCT) represent the main imaging modalities used in rhinosinusitis patients and are also important in odontogenic sinusitis (OS) diagnostics. Reports, however, often lack information on dentition. Here, we aimed to determine how maxillary dentition is initially interpreted in rhinosinusitis patients' CT/CBCT reports and which dental findings in particular are potentially missed, thus needing more attention. STUDY DESIGN: CT/CBCT scans and radiological reports from 300 rhinosinusitis patients were analysed focusing specifically on dental findings. An experienced oral and maxillofacial radiologist re-evaluated the scans and the assessment was compared to the original reports using the McNemar test. RESULTS: From the 300 original reports, 233 (77.7%) mentioned the maxillary teeth. The most frequent statement (126/300, 42.0%) was 'no apical periodontitis'. Apical periodontitis and severe alveolar bone loss were significantly overlooked (p < 0.001). Amongst the 225 patients for whom the CT/CBCT report initially lacked information on dental pathology, 22 patients were diagnosed with apical periodontitis and 16 with severe alveolar bone loss upon re-evaluation. CONCLUSIONS: Dental pathology remains underreported in rhinosinusitis patients' CT/CBCT reports. Because these reports affect OS diagnostics, a routine and structured review of the maxillary teeth by a radiologist is necessary. Such examinations should encompass the maxillary teeth.

My Favorite Sinus.

This essay reflects on the author's approach to interviewing applicants for medical residency in the otolaryngology department.

Effects of Endoscopic Sinus Surgery on Olfactory Bulb Volume among Patients with Chronic Rhinosinusitis: A Systematic Review and Meta-Analysis.

BACKGROUND: Endoscopic sinus surgery (ESS) could significantly improve olfactory function among patients with chronic rhinosinusitis (CRS). This study aimed to perform a meta-analysis to evaluate the effect of ESS on the olfactory bulb volume (OBV) among patients with CRS. METHODS: A systemic search of PubMed, Medline, Embase, Web of Science, and other databases was conducted to identify studies assessing OBV changes in patients with CRS after ESS utilizing magnetic resonance imaging. RESULTS: A total of four studies with 168 participants were included. Comparing the changes in OBV of patients with CRS before and after surgery within 3-6 months, the ESS significantly improved the overall OBV (P = 0.005, I2 = 66%), with the left OBV increased by 5.57mm3 (P = 0.84, I2 = 0%), and the right OBV increased by 8.63mm3 (P = 0.09, I2 = 53%). A difference in OBV persists between healthy controls and patients with CRS 3-6 months after ESS. The overall OBV of patients with CRS after ESS was significantly smaller than controls (mean difference = -3.84, P = 0.04), with a mean difference of 4.13mm3 on the left side (P = 0.72, I2 = 0%), and a mean difference of 3.22mm3 on the right side (P = 0.0001, I2 = 89%). CONCLUSIONS: ESS significantly increases the OBV among patients with CRS.

Evaluation of lamina papyracea dehiscence with paranasal computed tomography.

INTRODUCTION: The lamina papyracea is the thin line between the ethmoid sinus and the medial orbital wall. Knowledge of the presence of the lamina papyracea dehiscence (LPD) bears critical importance to prevent misdiagnosis of fractures at this level and to define the anatomy before sinonasal surgery, including Functional Endoscopic Sinus Surgery (FESS). The present study is therefore intended to determine the incidence of LPD in paranasal computed tomography, to identify its imaging characteristics in CT, and to compare with the literature. MATERIALS AND METHODS: The current study included patients who underwent paranasal CT scanning for any reason in our clinic between January 2018 and January 2022. Patients were evaluated in terms of age, gender, and presence of LPD. Patients with dehiscence were evaluated in terms of age, gender, dehiscence localization (right, left), tissue at the level of dehiscence, dehiscence size, and dehiscence grade. RESULTS: 1000 patients with a mean age of 32. ± 16.3 (min = 18-max = 79) were included in the study. 20 patients (2%) were found to have LPD. Of those with LPD, 14 (70%) were grade 1, 4 (20%) were grade 2 and 2 (10%) were grade 3. Again of those with LPD, 14 (70%) had LPD localized on the right and 6 (30%) had LPD on the left. In 12 (60%) of the patients with LPD, herniated tissue was detected. Among these patients with herniation, fatty tissue herniation was observed in 10 (83.3%) and medial rectus muscle herniation was observed in 2 (16.7%). DISCUSSION AND CONCLUSION: Comprehensive evaluation for and identification of LPD are very important before possible sinus surgery.