title: Design and evaluation of a 32-channel phased-array coil for lung imaging with hyperpolarized 3-helium.
abstract: Imaging with hyperpolarized 3-helium is becoming an increasingly important technique for MRI diagnostics of the lung but is hampered by long breath holds (>20 sec), which are not always applicable in patients with severe lung disease like chronic obstructive pulmonary disease (COPD) or alpha-1-anti-trypsin deficiency. Additionally, oxygen-induced depolarization decay during the long breath holds complicates interpretation of functional data such as apparent diffusion coefficients. To address these issues, we describe and validate a 1.5-T, 32-channel array coil for accelerated (3)He lung imaging and demonstrate its ability to speed up imaging (3)He. A signal-to-noise ratio increase of up to a factor of 17 was observed compared to a conventional double-resonant birdcage for unaccelerated imaging, potentially allowing increased image resolution or decreased gas production requirements. Accelerated imaging of the whole lung with one-dimensional and two-dimensional acceleration factors of 4 and 4 x 2, respectively, was achieved while still retaining excellent image quality. Finally, the potential of highly parallel detection in lung imaging is demonstrated with high-resolution morphologic and functional images.
authors.affiliation: Section of Medical Physics, Department of Diagnostic and Interventional Radiology, Johannes Gutenberg University Medical Center Mainz, Mainz, Germany.
authors.forename: Florian M
authors.initials: FM
authors.lastname: Meise
authors.forename: Julien
authors.initials: J
authors.lastname: Rivoire
authors.forename: Maxim
authors.initials: M
authors.lastname: Terekhov
authors.forename: Graham C
authors.initials: GC
authors.lastname: Wiggins
authors.forename: Boris
authors.initials: B
authors.lastname: Keil
authors.forename: Sergej
authors.initials: S
authors.lastname: Karpuk
authors.forename: Zahir
authors.initials: Z
authors.lastname: Salhi
authors.forename: Lawrence L
authors.initials: LL
authors.lastname: Wald
authors.forename: Laura M
authors.initials: LM
authors.lastname: Schreiber
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006371:Helium; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D007554:Isotopes; D008168:Lung / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers
chemical_list: D007554:Isotopes; D019275:Radiopharmaceuticals; D006371:Helium