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Sci—Thurs AM: YIS—09: Detection of Lung Remodeling Following Radiation Therapy Using Hyperpolarized 3 He Magnetic Resonance Imaging
Author(s) -
Mathew L,
Gaede S,
Wheatley A,
EtemadRezai R,
Rodrigues G,
Parraga G
Publication year - 2009
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3244169
Subject(s) - magnetic resonance imaging , medicine , effective diffusion coefficient , image registration , nuclear medicine , lung , radiology , medical imaging , image (mathematics) , artificial intelligence , computer science
Purpose: To assess subjects with clinically diagnosed radiation‐induced lung injury (RILI) at a single center using hyperpolarized3 He magnetic resonance imaging (MRI). Measurements of the3 He apparent diffusion coefficient (ADC) and percnt ventilated volume (PVV) were examined at an initial visit and 6‐month follow‐up. Furthermore, feasibility of3 He – 1 H ,3 He — CT and3 He — radiation planning image registration was evaluated. Methods: Seven subjects diagnosed with RILI provided written informed consent and were enrolled. Four subjects returned 22.0 ± 0.8 weeks later for a second visit. All subjects underwent spirometry and plethysmography. Three MR image sets were acquired at 3.0T; a1 He image, a static3 He ventilation image, and a3 He diffusion weighted image. PVV and ADC were evaluated for each lung independently and combined, and differences between lungs and between scans were evaluated. Feasibility of3 He registration was assessed for the center slice using the overlap coefficient. Results: At baseline, PVV was significantly different ( p = 0.025 ), and lower in the ipsilateral lung as compared to the contralateral lung. Significant increases were found in the contralateral lung for both ADC (mean increase 0.02 ± 0.01cm 2 / s , p = 0.003 ), and PVV (mean increase 16% ± 6%, p = 0.012 ). Good feasibility of3 He — CT registration was observed, with a center slice overlap coefficient of 75.3 ± 10.5. Conclusions: Hyperpolarized3 He MRI is well tolerated in subjects with moderate to severe RILI. Using this technique, structural and functional differences between lungs and over time can be detected in RILI subjects. Multi‐modality image registration incorporating3 He MRI is feasible.