Mucociliary clearance scan to evaluate primary ciliary dyskinesia in children with bronchiectasis

Objectives Primary ciliary dyskinesia (PCD) is characterized by functional or structural defects in the cilia causing abnormal ciliary motion and impaired mucociliary clearance. This leads to recurrent respiratory infections and bronchiectasis. Ciliary ultrastructure abnormalities can be identified. However, in some patients the ciliary ultrastructure may appear normal, suggesting functional abnormalities. Mucociliary clearance scan is a noninvasive procedure and can be used to evaluate mucociliary clearance function. The aim of this study was to evaluate the feasibility to use the mucociliary clearance scan in the PCD workup in children.

Methods Six mucociliary clearance scans were reviewed retrospectively in children with bronchiectasis and recurrent respiratory infection. Scans were performed using 99mTc Sulfur Colloid inhaled for 10 minutes with oxygen flow by whisper jet nebulizer system. Imaging in anterior view was obtained dynamically for 30 sec/frame over 60 minutes with the patient in supine position. Cinematic review of the data was performed by two experienced Nuclear Medicine physicians. The evaluation is based on the bolus movement of tracer from the main bronchi to the trachea and frequency. The final Clinical diagnosis was based on the combination of spirometry, chest radiograph, history and symptoms, ultrastructure evaluation, and nasal nitric oxide test.

Results Scans were normal in 4 children consistent with final diagnosis and clinical workup. Two children had a final diagnosis of PCD. One of them with a history of situs inversus had abnormal scan. No ciliary ultrastructure abnormalities were found. The study was limited in one patient due to noncooperation and suboptimal tracer distribution. However, no evidence of effective ciliary motion was noted. The nasal nitric oxide test was abnormal.

Conclusions Mucociliary Clearance Scan is a noninvasive procedure and can be used effectively as an adjunctive test in the work up of pediatric patient with suspected primary ciliary dyskinesia