Assessment of early bronchiectasis in young children with cystic fibrosis is dependent on lung volume.

OBJECTIVE: The aim of this study was to determine whether assessment of early CT scan-detected bronchiectasis in young children with cystic fibrosis (CF) depends on lung volume. METHODS: This study, approved by the hospital ethics committee, included 40 young children with CF from a newborn screened population contributing paired volume-controlled inspiratory and expiratory volumetric chest CT scans acquired under general anesthesia while clinically stable. Bronchiectasis was assessed with a semiquantitative CT scan score in inspiration and expiration, and the sensitivity of the expiratory CT scan to detect bronchiectasis was compared with the inspiratory CT scan by sensitivity and intraclass correlation coefficient analysis and Bland-Altman plots. Matched inspiratory and expiratory airway-vessel measurements were obtained in a subset of 10 children, and the relationship between lung volume and airway:vessel ratio after adjusting for age and vessel size was examined with the use of a linear regression model with generalized estimating equations. The number of visible airways in inspiration and expiration was compared in all 40 children by Wilcoxon signed rank test. RESULTS: Expiratory scans had poor sensitivity (0.46) to detect bronchiectasis, underestimating disease extent (P < .001). Airway:vessel ratios were consistently higher in inspiration, independent of age and vessel size (P < .001), with significantly more airways visible in inspiration than in expiration, independent of age (median, 71 vs 28, respectively; P < .001). CONCLUSIONS: In young children with CF, radiologic assessment of early bronchiectasis with chest CT scan depends on lung volume; thus, expiratory scans may not be appropriate for evaluating bronchiectasis in this population. Lung volume during CT image acquisition should be standardized to evaluate airway dimensions in young children.

Angle assessment by EyeCam, goniophotography, and gonioscopy.

PURPOSE: To compare EyeCam (Clarity Medical Systems, Pleasanton, CA) and goniophotography in detecting angle closure, using gonioscopy as the reference standard. METHODS: In this hospital-based, prospective, cross-sectional study, participants underwent gonioscopy by a single observer, and EyeCam imaging and goniophotography by different operators. The anterior chamber angle in a quadrant was classified as closed if the posterior trabecular meshwork could not be seen. A masked observer categorized the eyes as per the number of closed quadrants, and an eye was classified as having angle closure if there were 2 or more quadrants of closure. Agreement between the methods was analyzed by κ statistic and comparison of area under receiver operating characteristic curves (AUC). RESULTS: Eighty-five participants (85 eyes) were included, the majority of whom were Chinese. Angle closure was detected in 38 eyes (45%) with gonioscopy, 40 eyes (47%) using EyeCam, and 40 eyes (47%) with goniophotography (P=0.69 in both comparisons, McNemar test). The agreement for angle closure diagnosis (by eye) between gonioscopy and the 2 imaging modalities was high (κ=0.86; 95% Confidence Interval (CI), 0.75-0.97), whereas the agreement between EyeCam and goniophotography was not as good (κ=0.72; 95% CI, 0.57-0.87); largely due to lack of agreement in the nasal and temporal quadrants (κ=0.55 to 0.67). The AUC for detecting eyes with gonioscopic angle closure was similar for goniophotography and EyeCam (AUC 0.93, sensitivity=94.7%, specificity=91.5%; P>0.95). CONCLUSIONS: EyeCam and goniophotography have similarly high sensitivity and specificity for the detection of gonioscopic angle closure.