Note: This copy is for your personal, non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, contact us at www.rsna.org/rsnarights. ORIGINAL RESEARCH n THORACIC IMAGING Radiology: Volume 255: Number 1—April 2010 n radiology.rsna.org 225 Hyperpolarized 3 He MR for Sensitive Imaging of Ventilation Function and Treatment Efficiency in Young Cystic Fibrosis Patients with Normal Lung Function 1 Elise Bannier, MSc Katarzyna Cieslar, PhD Karim Mosbah, MD Françoise Aubert, TBD François Duboeuf, PhD Zahir Salhi, PhD Sophie Gaillard, MSc Yves Berthezène, MD, PhD Yannick Crémillieux, PhD Philippe Reix, MD, PhD Purpose: To assess the sensitivity of hyperpolarized helium 3 ( 3 He) magnetic resonance (MR) imaging for the detection of pe- ripheral airway obstruction in younger cystic fibrosis (CF) patients showing normal spirometric results (mean forced expiratory volume in 1 second [FEV 1 ], 112% 6 14.5 [stan- dard deviation]) and to observe the immediate effects of a single chest physical therapy (CPT) session, thereby com- paring 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 3 He 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 ven- tilated 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 6 1.9; mean global VF, 78.5% 6 12.3; and mean peripheral VF, 75.5% 6 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 6 1.1; mean global VF, 83.5% 6 12.2; and mean peripheral VF, 80.3% 6 12.2). There was no correlation between FEV 1 and VDI ( r = 20.041, P = .863) or global VF ( r = 20.196, P = .408) values but peripheral VF and VDI were corre- lated ( r = 20.563, P = .011). Conclusion: Although spirometric results indicate normal lung func- tion, 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 dispa- rate changes in the distribution and extent of ventilation defects. q RSNA, 2010 1 From the CREATIS LRMN, CNRS UMR 5220 INSERM U630, Université de Lyon, 43 boulevard du 11 Novembre, 69622 Villeurbanne, France (E.B., K.C., K.M., F.D., S.G., Y.B., Y.C.); Centre d’Investigation Clinique, Lyon, France (F.A.); Johannes Gutenberg Universität, Mainz, Germany (Z.S.); and Service de Pédiatrie, Pneumologie, Allergologie, Mucoviscidose, Hôpital Femme Mère Enfant, Lyon, France (P.R.). Received January 6, 2009; revision requested March 17; revision received September 8; accepted September 16; final version accepted October 26. Supported by Vaincre La Mucoviscidose, the Hospices Civils de Lyon, and the European Union Marie Curie Research Training Network PHeLINet (no. MRTN-CT-2006-036002). Method- ologic approach was prepared with the support of Centre d’Investigation Clinique de Lyon. Address correspondence to Y.C. (e-mail: yannick.cremillieux@univ-lyon1.fr). q RSNA, 2010