Multicenter Observational Study to Evaluate the Diagnostic Value of Sonography in Patients with Chronic Rhinosinusitis

Abstract

(1) Background: Computed tomography (CT) is considered mandatory for assessing the extent of pathologies in the paranasal sinuses (PNS) in chronic rhinosinusitis (CRS). However, there are few evidence-based data on the value of ultrasound (US) in CRS. This multicenter approach aimed to compare diagnostic imaging modalities in relation to findings during surgery. (2) Methods: 127 patients with CRS were included in this prospective multicenter study. Patients received preoperative US and CT scans. The sensitivity and specificity of CT and US were extrapolated from intraoperative data. (3) Results: CT scans showed the highest sensitivity (97%) and specificity (67%) in assessing CRS. Sensitivities of B-scan US were significantly lower regarding the maxillary sinus (88%), the ethmoid sinus (53%), and the frontal sinus (45%). The highest overall sensitivity was observed for assessing the pathology of the maxillary sinus. (4) Conclusions: We observed high accuracy with CT, confirming its importance in preoperative imaging in CRS. Despite the high US expertise of all investigators and a standardized examination protocol, the validity of CT was significantly higher than US. Ultrasound of the PNS sinuses is applicable in everyday clinical practice but lacks diagnostic accuracy. Nevertheless, it might serve as a complementary hands-on screening tool to directly correlate the clinical findings in patients with PNS disease.

Keywords: A-scan; B-scan; chronic rhinosinusitis; computed tomography; diagnostic imaging; paranasal sinuses; sonography; ultrasound.

Figure 1

CT scan in three spatial planes in a patient suffering from CRS. (a) Coronal reconstruction with opacification of the maxillary sinus and the ethmoid sinus bilaterally on both sides. (b) Axial reconstruction; when viewed together with A, it can be observed that there is a subtotal obstruction in both maxillary sinuses due to secretion and mucosal swelling. (c) Sagittal reconstruction; the frontal sinus is largely unaffected. There is discrete residual ventilation in the cranial part of the maxillary sinus.

Figure 2

Intraoperative endoscopic view during paranasal sinus surgery in CRS. Nasal polyps (NP) embracing the middle turbinate (MT) and the inferior turbinate (IT) and reaching the nasal septum (NS).

Figure 3

B-scan US of corresponding maxillary sinus from Figure 2. The osseus anterior wall of the maxillary sinus (AWMS) is identified at 1 cm depth. At a depth of 4.33 cm, the backscatter echo is depicted as hyperechoic back wall reflex (PWMS = posterior wall of the maxillary sinus).

Figure 4

Transducer-positions in B-mode ultrasound of the paranasal sinuses. (a,b): Examination of the maxillary sinus in the axial plane. The transducer is positioned horizontally below the orbit on the anterior wall of the maxillary sinus. (c,d): Examination of the ethmoid sinus in a parasagittal plane. The transducer is positioned vertically in the medial corner of the eye following the course of the medial orbital wall. (e,f): Examination of the frontal sinus in the axial plane. The transducer is positioned horizontally in the lower midline of the forehead.