Spirometry-assisted HRCT in children helps detect early signs of CT lung disease

Is spirometry assisted high-resolution computed tomography (HRCT) on the chests of children worth a clinician's effort, time and financial commitment? 

A study, published Oct. 30 in Current Problems in Diagnostic Radiology, attempts to answer that very question. The ultimate goal of the research was to determine if children being coached through breath holds while undergoing an HRCT could improve overall image quality. The image quality of HRCT is dependent on adequate breath holds from the patient, which in most cases is arguably harder to accomplish with children than adults.   

Data for the study were taken from HRCTs conducted at a children's hospital before and after the spirometry-assisted CT scans of 50 children over 8 years old.  

"Spirometry-assisted CT scans were matched by age, gender and diagnosis (cystic fibrosis vs other) to CT scans obtained with voluntary breath holds in the six years before implementation of the spirometry assistance protocol (controls), and evaluated by two blinded pediatric radiologists," said lead author of the study Jeffrey Parke Otjen, MD.  

The children were then trained by a respiratory therapist on proper breathing techniques and holds prior to their CT scan, which they repeated with a respiratory therapist coaching them.  

The researchers were unable to successfully detect if image quality improved on inspiratory scans more than expiratory scans. However, they did find that, of the 50 children analyzed, 10 carried the diagnosis of cystic fibrosis.  

Most notably concluded from the study, researchers gathered that spirometry-assisted CT scans are likely to result in improved detection of air trapping, an important sign to in further detecting early peripheral airway obstruction in cystic fibrosis lung disease. Additionally, the 50 children in the study were able to achieve a median of 95 percent of their best inspiratory and expiratory slow vital capacity during CT scanning.  

"Spirometry assistance during CT scanning improves the lung volumes at which inspiratory and, particularly, expiratory images are obtained and allows quantification of lung volumes relative to the patient’s best slow vital capacities," Otjen concluded. "However, the additional time, cost, and scheduling considerations necessary for spirometry-assisted scans may make this protocol difficult to justify for routine use in all HRCT examinations."