Ultrasound as a Preoperative Imaging Tool for Nasal Dorsum Cysts and Fistulas: A Single-Center Retrospective Study of 87 Patients.

Nasal dorsum cysts and fistulas (NDCF) are rare congenital malformations whose surgical resection depends on the possible presence of intracranial extension (ICE). MRI and CT scans are recommended for preoperative assessment. The objective of the study was to evaluate the ultrasound's performance in detecting ICE. Methods. Retrospective, single-center, tertiary descriptive study including patients who underwent surgery for NDCF between 2004 and 2023. All patients underwent at least one preoperative imaging examination. The imaging results were compared with the surgical findings. The parameters calculated were sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy. Eighty-seven patients were included. The mean age at diagnosis was 2.31 (±5.06) years. There were 63 cysts (72.41%), 17 fistulas (19.54%), and 7 combined forms (8.05%). A total of 54 ultrasounds, 64 MRIs, and 17 CT scans were performed. Height patients (9.20%) had ICE. Negative predictive values were 100% (ultrasound), 98% (MRI), and 91% (CT scan). Ultrasound had 98% accuracy, with 1 false positive and no false negatives. Conclusion. Ultrasound, performed by an experienced pediatric radiologist, is an effective first-line test for excluding ICE in cases of NDCF. In cases of doubtful diagnosis, MRI or CT scan remains necessary depending on the age of the patient.