Computed Tomography Findings of Bronchiectasis in Different Respiratory Phases Correlate with Pulmonary Function Test Data in Adults.

OBJECTIVE: To investigate bronchiectasis variations in different computed tomography (CT) respiratory phases, and their correlation with pulmonary function test (PFT) data, in adults. METHODS: Retrospective data analysis from 63 patients with bronchiectasis according to CT criteria selected from the institution database and for whom PFT data were also available. Bronchiectasis diameter was measured on inspiratory and expiratory phases. Its area and matched airway-vessel ratios in both phases were also calculated. Finally, PFT results were compared with radiological measurements. RESULTS: Bronchiectatic airways were larger on inspiration than on expiration (mean cross-sectional area, 69.44 vs. 40.84 mm2; p < 0.05) as were airway-vessel ratios (2.1 vs. 1.4; p < 0.05). Cystic bronchiectasis cases showed the least variation in cross-sectional area (48%). Mean predicted values of forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were 81.5 and 77.2%, respectively, in the group in which bronchiectasis could not be identified on expiratory images, and 58.3 and 56.0%, respectively, in the other group (p < 0.05). Variation in bronchiectasis area was associated with poorer lung function (r = 0.32). CONCLUSION: Bronchiectasis detection, diameter, and area varied significantly according to CT respiratory phase, with non-reducible bronchiectasis showing greater lung function impairment.

Multidetector Computed Tomography Findings in Pulmonary Hamartomas: A New Fat Detection Threshold.

PURPOSE: The aim of the study was to determine the accuracy of multidetector computed tomography in the evaluation of histologically confirmed pulmonary hamartomas (PHs), with a special focus on fat detection. MATERIALS AND METHODS: Data from 55 patients who had received a histologically confirmed diagnosis of PH and had undergone 64-slice thoracic MDCT were retrospectively evaluated. RESULTS: PHs manifested predominantly as peripheral pulmonary nodules with lobulated margins. The average lesion diameter was 1.51 cm (SD 0.6 cm). Histologic analyses identified fat content in 43/55 (78.2%) surgical specimens. The accuracy, sensitivity, and specificity of fat detection at a density threshold of -40 HU were 83.7%, 100%, and 87.2%, respectively. A threshold of -33 HU yielded better results (95.3%, 100%, and 96.3%, respectively). Popcorn-like calcifications were found in only 12/55 (21.8%) PHs and were the only imaging feature suggestive of PH in 7.2% of cases. Most (66%) lesions with popcorn-like calcifications also contained fat. CONCLUSIONS: The adoption of a new threshold for fat content (<-33 HU) can lead to further improvements in the overall ability to detect PHs by CT.