Hyperpolarized (3)He magnetic resonance imaging-derived pulmonary pressure-volume curves.
We aimed to evaluate the potential for the use of hyperpolarized helium-3 magnetic resonance imaging (MRI) apparent diffusion coefficient (ADC) surrogates of alveolar size, together with literature-based morphological parameters in a theoretical model of lung mechanics to simulate noninvasive transpulmonary pressure-volume curves. Fourteen ex-smokers with chronic obstructive pulmonary disease (COPD) (n = 8 stage II, n = 6 stage III/IV COPD) and five age-matched never-smokers, provided written, informed consent and were evaluated at baseline and 26 + or - 2 mo later (n = 15 subjects) using plethysmography, spirometry, and (3)He MRI at 3.0 T. Total lung capacity, residual volume, and literature-based morphological parameters were used with alveolar volumes derived from (3)He ADC to simulate noninvasive pressure-volume curves. The resultant anterior-posterior transpulmonary pressure gradient was significantly decreased for stage II COPD (P < 0.01) and stage III COPD subjects (P < 0.001) compared with healthy volunteers. Both COPD subgroups showed increased alveolar radius compared with healthy subjects (P < 0.01, stage II COPD; P < 0.001, stage III COPD). In addition, surface area and surface tension were significantly increased in stage III COPD compared with healthy volunteers (P < 0.01). These results suggest that (3)He MRI provides a potential noninvasive approach to evaluate lung mechanics regionally and further supports the use of ADC values as a regional noninvasive probe of pulmonary microstructure and compliance.
Imaging Research Laboratories, Robarts Research Institute, PO Box 5015, 100 Perth Dr., London, Ontario, Canada N6A 5K8.
Stephen
S
Choy
Andrew
A
Wheatley
David G
DG
McCormack
Grace
G
Parraga
D000368:Aged; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D005541:Forced Expiratory Volume; D006371:Helium; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008168:Lung / Q000473:pathology* / Q000503:physiopathology*; D008170:Lung Compliance; D008176:Lung Volume Measurements; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009864:Ontario; D010865:Pilot Projects; D010991:Plethysmography; D011237:Predictive Value of Tests; D011312:Pressure; D011650:Pulmonary Alveoli / Q000473:pathology / Q000503:physiopathology; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D012115:Residual Volume; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects; D016540:Smoking Cessation; D013147:Spirometry; D013997:Time Factors; D014109:Total Lung Capacity; D014797:Vital Capacity
D006371:Helium