Frontal Sinus

We precisely defined optode locations using a typical fNIRS probe arrangement (ETG-4000, Hitachi Medical Systems, Japan), which was positioned over the right prefrontal cortex. A set of optodes, which correspond to 24 fNIRS recording channels each consisting of an NIR-light emitter-detector pair, was used in the present study. The probe set was placed in respect to the Fpz surface marker of the International EEG 10–20 system (figure 8). Specifically, the light emitter of the NIRS-channel #1 and #4, respectively, was placed on Fpz while the bottom row of NIRS optodes of the probe set was located on a line from Fpz to F8. A previous pilot fNIRS-fMRI measurement confirmed feasibility of identification of precise optode positions as probe-holder of each optode and/or slight skin indentation by optode tips were visible in the structural image. This positional information defined native spatial coordinates of the 24 NIRS channels in each subject using the MRIcro software [34] (link). The channel coordinates between two optodes were normalized to MNI-space using SPM8 normalization routines. The normalized coordinates were then spatially averaged over all subjects and indicated by blobs of 5 voxels diameter using MRIcro. The channels #1, #2 and #4 are mostly associated with parts of the frontal sinus with most volume underneath channel #1. The normalized and averaged probe set is displayed in figure 8.

CT examinations were carried out using GE Light speed 16-slice and Siemens SOMATOM Definition 40-slice spiral CT scanners. Axial and coronal plain scanning and enhanced axial venous scanning were performed. Scanning parameters: tube current: 300mA; tube voltage: 120kV; matrix: 512x512; layer thickness: 3mm; window width: 250HU; and window level: 50HU. MR examinations were conducted using Siemens 1.5T, GE 3.0T magnetic resonance scanners, and quadrature head coil. Axial and coronal plain scanning, and enhanced axial, coronal and sagittal scanning were performed. Scanning parameters: T1WI: TR=230, TE=2.30; T2WI: TR=2800, TE=82.12; STIR sequences in coronal positions: TR=3200, TE=2.70; matrix: 256x256, layer thickness: 4mm, and interval: 1mm. Contrast-enhanced CT and MR scanning were respectively administered with the contrast agents of non-ionic iodine (ioversol, iohexol, dosage of 1.5ml/kg, flow rate of 3ml/s) and Gd-DTPA (dosage of 0.1mmol/kg, flow rate of 2ml/s) intravenously injected through the cubital vein with high-pressure syringe. The scanning range of CT and MR: the axial scanning was from the upper edge of the frontal sinus to the lower edge of the second cervical vertebra, while the coronal scanning was from the frontal sinus to the posterior edge of the sphenoid sinus, and the sagittal scanning covered the whole nasal cavity and paranasal sinuses.

The demographic information (including age and sex) and clinical characteristic (including SIgE test results, serum eosinophil count, eosinophilic granulocytes, visual analog scale [VAS] score, computerized tomography [CT] scoeosinophilre, endoscopic score, the sino‐nasal outcome Test‐20 [SNOT‐22] score) were collected.
The SIgE test results before surgery were collected. The semi‐quantitative detection unit of specific allergen IgE was IU/mL, and the grades were classified into: grade 0, normal, <0.35; grade 1, mild, 0.35–0.7; grade 2, moderate, 0.7–3.5; grade 3, severe, >3.5. Grade 0 was considered negative, and grades 1–3 were considered positive.
The subjective symptoms of rhinosinusitis (nasal obstruction, nasal discharge, and swelling pain in the nasal and facial area) of all the patients before surgery were scored using a VAS score. The range from 0 to 10 represented symptoms gradually aggravating.
The eosinophilic granulocytes in the nasal polyp tissue of the enrolled patients after surgery were counted. If the count was ≥10/HPF, it was defined as ECRS, and if the count was <10/HPF, it was defined as non‐ECRS CRS_wNP.¹⁹The Lund‐Mackay CT score¹⁹ was used to grade the extent of lesions on the coronal CT of the paranasal sinus of the patients before surgery, including the bilateral anterior and posterior sinuses and the ostiomeatal complexes. For the paranasal sinus, 0 represented normal, 1 represented partial shadow, and 2 represented complete shadow. For the ostiomeatal complex, 0 represented no obstruction, and 2 represented obstruction. A maximum of 12 points were scored for each side.
The Lund‐Kennedy score¹⁹ was used to grade the preoperative nasal endoscopy of the patients as endoscopic score, which was divided into three grades: 0 meant that no nasal polyp was found; 1 meant that the size of the nasal polyp did not exceed the middle nasal concha; 2 meant that the lower end of the nasal polyp exceeded the middle nasal concha. Edema: 0 point, no edema; 1 point, slight edema; 2 points, severe edema. Discharge: 0 point, no rhinorrhea; 1 point, clear and thin nose leakage; 2 points, viscous and purulent rhinorrhea.
SNOT‐20²⁰ score was used to score the preoperative questionnaire investigation of the enrolled patients. The Chinese version of SNOT‐22 includes a total of 22 symptoms, involving three aspects: physiological problems, functional limitations and emotional outcomes. The respondents were asked to score 22 symptoms according to their own symptoms of sinusitis. A score of 0 means that they have no problems; 1 point means that the respondent is slightly troubled; 2 points represent moderate distress to the respondents; A score of 3 indicates that the respondents are seriously troubled. The higher the total score of 20 symptoms, the worse the quality of life of the respondents.