{'fraction_non_alphanumeric': 0.041053446940356314, 'fraction_numerical': 0.027885360185902403, 'mean_word_length': 4.81981981981982, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 2, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Evaluation of Lung Volumetry Using Dynamic Three-Dimensional Magnetic Resonance Imaging

Rationale and Objectives:We sought to investigate lung volume and surface measurements during the breathing cycle using dynamic three-dimensional magnetic resonance imaging (3D MRI). Materials and Methods:Breathing cycles of 20 healthy volunteers were examined using a 2D trueFISP sequence (3 images/second) in combination with a model and segmented 3D FLASH sequence (1 image/second) MR images using view sharing. Segmentation was performed semiautomatically using an interactive region growing technique. Vital capacity (VC) was calculated from MRI using the model (2D) and counting the voxels (3D) and was compared with spirometry. Results:VC from spirometry was 4.9 ± 0.9 L, 4.4 ± 1.2 L from 2D MRI measurement, and 4.7 ± 0.9 L for 3D MRI. Using the 3D technique, correlation to spirometry was higher than using the 2D technique (r > 0.95 vs. r > 0.83). Using the 3D technique, split lung volumes and lung surface could be calculated. There was a significant difference between the left and right lung volume in expiration (P < 0.05). Conclusions:Dynamic 3D MRI is a noninvasive tool to evaluate split lung volumes and lung surfaces during the breathing cycle with a high correlation to spirometry.