Lukas Ebner1,2, Rohan S Virgincar3, Mu He3,4, Kingshuk R Choudhury1, Scott H Robertson3,4, Andreas Christe2, Achille Mileto5, Joseph G Mammarapallil1, H Page McAdams1, Bastiaan Driehuys1,2,3,5, Justus E Roos6. 1. 1 Department of Radiology, Duke University Medical Center, 2301 Erwin Rd, Box 3808, Durham, NC 27710. 2. 2 Department of Diagnostic, Interventional and Paediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland. 3. 3 Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC. 4. 4 Department of Radiology, University of Washington School of Medicine, Seattle, WA. 5. 5 Department of Radiology, Cantonal Hospital, Lucerne, Switzerland. 6. 6 Department of Radiology and Nuclear Medicine, Cantonal Hospital, Lucerne, Switzerland.
Abstract
OBJECTIVE: The objective of our study was to identify the magnitude and distribution of ventilation defect scores (VDSs) derived from hyperpolarized (HP) 129Xe-MRI associated with clinically relevant airway obstruction. MATERIALS AND METHODS: From 2012 to 2015, 76 subjects underwent HP 129Xe-MRI (48 healthy volunteers [mean age ± SD, 54 ± 17 years]; 20 patients with asthma [mean age, 44 ± 20 years]; eight patients with chronic obstructive pulmonary disease [mean age, 67 ± 5 years]). All subjects underwent spirometry 1 day before MRI to establish the presence of airway obstruction (forced expiratory volume in 1 second-to-forced vital capacity ratio [FEV1/FVC] < 70%). Five blinded readers assessed the degree of ventilation impairment and assigned a VDS (range, 0-100%). Interreader agreement was assessed using the Fleiss kappa statistic. Using FEV1/FVC as the reference standard, the optimum VDS threshold for the detection of airway obstruction was estimated using ROC curve analysis with 10-fold cross-validation. RESULTS: Compared with the VDSs in healthy subjects, VDSs in patients with airway obstruction were significantly higher (p < 0.0001) and significantly correlated with disease severity (r = 0.66, p < 0.0001). Ventilation defects in subjects with airway obstruction did not show a location-specific pattern (p = 0.158); however, defects in healthy control subjects were more prevalent in the upper lungs (p = 0.014). ROC curve analysis yielded an optimal threshold of 12.4% ± 6.1% (mean ± SD) for clinically significant VDS. Interreader agreement for 129Xe-MRI was substantial (κ = 0.71). CONCLUSION: This multireader study of a diverse cohort of patients and control subjects suggests a 129Xe-ventilation MRI VDS of 12.4% or greater represents clinically significant obstruction.
OBJECTIVE: The objective of our study was to identify the magnitude and distribution of ventilation defect scores (VDSs) derived from hyperpolarized (HP) 129Xe-MRI associated with clinically relevant airway obstruction. MATERIALS AND METHODS: From 2012 to 2015, 76 subjects underwent HP 129Xe-MRI (48 healthy volunteers [mean age ± SD, 54 ± 17 years]; 20 patients with asthma [mean age, 44 ± 20 years]; eight patients with chronic obstructive pulmonary disease [mean age, 67 ± 5 years]). All subjects underwent spirometry 1 day before MRI to establish the presence of airway obstruction (forced expiratory volume in 1 second-to-forced vital capacity ratio [FEV1/FVC] < 70%). Five blinded readers assessed the degree of ventilation impairment and assigned a VDS (range, 0-100%). Interreader agreement was assessed using the Fleiss kappa statistic. Using FEV1/FVC as the reference standard, the optimum VDS threshold for the detection of airway obstruction was estimated using ROC curve analysis with 10-fold cross-validation. RESULTS: Compared with the VDSs in healthy subjects, VDSs in patients with airway obstruction were significantly higher (p < 0.0001) and significantly correlated with disease severity (r = 0.66, p < 0.0001). Ventilation defects in subjects with airway obstruction did not show a location-specific pattern (p = 0.158); however, defects in healthy control subjects were more prevalent in the upper lungs (p = 0.014). ROC curve analysis yielded an optimal threshold of 12.4% ± 6.1% (mean ± SD) for clinically significant VDS. Interreader agreement for 129Xe-MRI was substantial (κ = 0.71). CONCLUSION: This multireader study of a diverse cohort of patients and control subjects suggests a 129Xe-ventilation MRI VDS of 12.4% or greater represents clinically significant obstruction.
Authors: Mu He; Scott H Robertson; S Sivaram Kaushik; Matthew S Freeman; Rohan S Virgincar; John Davies; Jane Stiles; William M Foster; H Page McAdams; Bastiaan Driehuys Journal: Magn Reson Imaging Date: 2015-04-30 Impact factor: 2.546
Authors: Helen K Reddel; D Robin Taylor; Eric D Bateman; Louis-Philippe Boulet; Homer A Boushey; William W Busse; Thomas B Casale; Pascal Chanez; Paul L Enright; Peter G Gibson; Johan C de Jongste; Huib A M Kerstjens; Stephen C Lazarus; Mark L Levy; Paul M O'Byrne; Martyn R Partridge; Ian D Pavord; Malcolm R Sears; Peter J Sterk; Stuart W Stoloff; Sean D Sullivan; Stanley J Szefler; Mike D Thomas; Sally E Wenzel Journal: Am J Respir Crit Care Med Date: 2009-07-01 Impact factor: 21.405
Authors: Mu He; S Sivaram Kaushik; Scott H Robertson; Matthew S Freeman; Rohan S Virgincar; H Page McAdams; Bastiaan Driehuys Journal: Acad Radiol Date: 2014-09-26 Impact factor: 3.173
Authors: Lukas Ebner; Jeff Kammerman; Bastiaan Driehuys; Mark L Schiebler; Robert V Cadman; Sean B Fain Journal: Eur J Radiol Date: 2016-09-16 Impact factor: 3.528
Authors: Miranda Kirby; Sarah Svenningsen; Amir Owrangi; Andrew Wheatley; Adam Farag; Alexei Ouriadov; Giles E Santyr; Roya Etemad-Rezai; Harvey O Coxson; David G McCormack; Grace Parraga Journal: Radiology Date: 2012-09-05 Impact factor: 11.105
Authors: Justus E Roos; Holman P McAdams; S Sivaram Kaushik; Bastiaan Driehuys Journal: Magn Reson Imaging Clin N Am Date: 2015-05 Impact factor: 2.266