Hyperpolarized 3He MR for Sensitive Imaging of Ventilation Function and Treatment Efficiency in Young Cystic Fibrosis Patients with Normal Lung Function
Abstract
Given the sensitivity of hyperpolarized 3He MR imaging in depicting small ventilation defects in young asymptomatic cystic fibrosis patients, this technique could play a major role to study treatment at an early stage of the disease.
Purpose
To assess the sensitivity of hyperpolarized helium 3 (3He) magnetic resonance (MR) imaging for the detection of peripheral airway obstruction in younger cystic fibrosis (CF) patients showing normal spirometric results (mean forced expiratory volume in 1 second [FEV1], 112% ± 14.5 [standard deviation]) and to observe the immediate effects of a single chest physical therapy (CPT) session, thereby comparing two image quantification techniques.
Materials and Methods
Ten pediatric CF patients (age range, 8–16 years) with normal spirometric results were included in this study after approval from the local research ethics committee. Spirometry followed by proton and hyperpolarized 3He three-dimensional lung imaging were performed with a 1.5-T MR unit before and after 20 minutes of CPT. The number of ventilation defects per image (VDI) and the ventilated lung fraction (VF), defined as the ratio of ventilated lung volume divided by total lung volume, were quantified.
Results
Ventilation defects were found in all patients (mean VDI, 5.1 ± 1.9; mean global VF, 78.5% ± 12.3; and mean peripheral VF, 75.5% ± 17.1) despite normal spirometric results. After CPT, disparate changes in the distribution of ventilation defects were observed but the average VDI and VF did not change significantly (mean VDI, 5.1 ± 1.1; mean global VF, 83.5% ± 12.2; and mean peripheral VF, 80.3% ± 12.2). There was no correlation between FEV1 and VDI (ρ = −0.041, P = .863) or global VF (ρ = −0.196, P = .408) values but peripheral VF and VDI were correlated (ρ = −0.563, P = .011).
Conclusion
Although spirometric results indicate normal lung function, the mean VDI in patients (5.1) found in this study is well above the VDI in healthy subjects (1.6) reported in the literature. A single CPT session induces disparate changes in the distribution and extent of ventilation defects.
© RSNA, 2010
References
- 1 . Cystic fibrosis mortality and survival in the UK: 1947–2003. Eur Respir J 2007;29(3):522–526. Crossref, Medline, Google Scholar
- 2 . Guidelines for implementation of cystic fibrosis newborn screening programs: Cystic Fibrosis Foundation workshop report. Pediatrics 2007;119(2):e495–e518. Crossref, Medline, Google Scholar
- 3 . Monitoring cystic fibrosis lung disease in clinical trials: is it time for a change?. Proc Am Thorac Soc 2007;4(4):297–298. Crossref, Medline, Google Scholar
- 4 Lung function testing: selection of reference values and interpretative strategies: American Thoracic Society. Am Rev Respir Dis 1991;144(5):1202–1218. Crossref, Medline, Google Scholar
- 5 . High-resolution computed tomography of the lung in children with cystic fibrosis: technical factors. Proc Am Thorac Soc 2007;4(4):306–309. Crossref, Medline, Google Scholar
- 6 . Radiation-induced cancer risk from annual computed tomography for patients with cystic fibrosis. Am J Respir Crit Care Med 2007;176(10):970–973. Crossref, Medline, Google Scholar
- 7 . Magnetic resonance imaging of the lung in cystic fibrosis. Proc Am Thorac Soc 2007;4(4):321–327. Crossref, Medline, Google Scholar
- 8 . Assessment of human pulmonary function using oxygen-enhanced T(1) imaging in patients with cystic fibrosis. Magn Reson Med 2004;51(5):1009–1016. Crossref, Medline, Google Scholar
- 9 . Assessment of hemodynamic changes in the systemic and pulmonary arterial circulation in patients with cystic fibrosis using phase-contrast MRI. Eur Radiol 2005;15(8):1575–1580. Crossref, Medline, Google Scholar
- 10 . Contrast-enhanced 3D MRI of lung perfusion in children with cystic fibrosis: initial results. Eur Radiol 2006;16(10):2147–2152. Crossref, Medline, Google Scholar
- 11 . Normal and abnormal pulmonary ventilation: visualization at hyperpolarized He-3 MR imaging. Radiology 1996;201(2):564–568. Link, Google Scholar
- 12 . Human lung air spaces: potential for MR imaging with hyperpolarized He-3. Radiology 1996;200(2):553–558. Link, Google Scholar
- 13 . Lung air spaces: MR imaging evaluation with hyperpolarized 3He gas. Radiology 1999;210(3):851–857. Link, Google Scholar
- 14 . Cystic fibrosis: combined hyperpolarized 3He-enhanced and conventional proton MR imaging in the lung—preliminary observations. Radiology 1999;212(3):885–889. Link, Google Scholar
- 15 . Hyperpolarized HHe 3 MRI of the lung in cystic fibrosis: assessment at baseline and after bronchodilator and airway clearance treatment. Acad Radiol 2005;12(11):1423–1429. Crossref, Medline, Google Scholar
- 16 . Hyperpolarized 3helium magnetic resonance ventilation imaging of the lung in cystic fibrosis: comparison with high resolution CT and spirometry. Eur Radiol 2006;16(11):2483–2490. Crossref, Medline, Google Scholar
- 17 . Quantitative analysis of regional airways obstruction using dynamic hyperpolarized 3He MRI-preliminary results in children with cystic fibrosis. J Magn Reson Imaging 2005;22(3):420–426. Crossref, Medline, Google Scholar
- 18 . Assessment of lung disease in children with cystic fibrosis using hyperpolarized 3-Helium MRI: comparison with Shwachman score, Chrispin-Norman score and spirometry. Eur Radiol 2007;17(4):1018–1024. Crossref, Medline, Google Scholar
- 19 . Standardisation of spirometry. Eur Respir J 2005;26(2):319–338. Crossref, Medline, Google Scholar
- 20 . Maximum expiratory flow-volume curves and airway conductance in children and adolescents. J Appl Physiol 1969;26(3):308–316. Crossref, Medline, Google Scholar
- 21 . MR imaging of the lungs with hyperpolarized helium-3 gas transported by air. Phys Med Biol 2002;47(13):N185–N190. Crossref, Medline, Google Scholar
- 22 . Long-term study of one hundred five patients with cystic fibrosis; studies made over a five- to fourteen-year period. AMA J Dis Child 1958;96(1):6–15. Crossref, Medline, Google Scholar
- 23 . Evaluation of scoring system of the chest radiograph in cystic fibrosis: a collaborative study. AJR Am J Roentgenol 1980;134(6):1195–1198. Crossref, Medline, Google Scholar
- 24 . Combined helium-3/proton magnetic resonance imaging measurement of ventilated lung volumes in smokers compared to never-smokers. J Magn Reson Imaging 2005;21(4):365–369. Crossref, Medline, Google Scholar
Article History
Received January 6, 2009; revision requested March 17; revision received September 8; accepted September 16; final version accepted October 26.Published online: Mar 10 2010
Published in print: Apr 2010