title: Intracranial microvascular imaging at 7 T MRI with transceiver RF coils.
abstract: OBJECTIVE
  To investigate intracranial microvascular images with transceiver radio-frequency (RF) coils at ultra-high field 7 T magnetic resonance imaging (MRI).
  
  
  METHODS
  We designed several types of RF coils for the study of 7 T magnetic resonance angiography and analyzed quantitatively each coil's performance in terms of the signal-to-noise ratio (SNR) profiles to evaluate the usefulness of RF coils for microvascular imaging applications. We also obtained the microvascular images with different resolutions and parallel imaging technique.
  
  
  RESULTS
  The overlapped 6-channel (ch) transceiver coil exhibited the highest performance for angiographic imaging. Although other multi-channel coils, such as 4- or 8-ch, were also suitable for fast imaging, these coils performed poorly in homogeneity or SNR for angiographic imaging. Furthermore, the 8-ch coil was poor in SNR at the center of the brain, while it had the highest SNR at the periphery.
  
  
  CONCLUSIONS
  The present study has demonstrated that the overlapped 6-ch coil with large-size loop coils provided the best performance for microvascular imaging or angiography with the ultra-high-field 7 T MRI, mainly because of its long penetration depth together with high SNR.
authors.affiliation: Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea; Department of Radiological Science, College of Health Science, Gachon University, Incheon, Republic of Korea.
authors.forename: Chang-Ki
authors.initials: CK
authors.lastname: Kang
authors.affiliation: Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea.
authors.forename: Myung-Kyun
authors.initials: MK
authors.lastname: Woo
authors.affiliation: Institute of Neuroscience and Medicine - 4, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Suk-Min
authors.initials: SM
authors.lastname: Hong
authors.affiliation: Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea.
authors.forename: Young-Bo
authors.initials: YB
authors.lastname: Kim
authors.affiliation: Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea. Electronic address: zhcho36@gmail.com.
authors.forename: Zang-Hee
authors.initials: ZH
authors.lastname: Cho
mesh_terms: D001921:Brain / Q000098:blood supply*; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D019047:Phantoms, Imaging; D011846:Radio Waves; D059629:Signal-To-Noise Ratio
keywords: 7T MRI; MRA; Microvascular imaging; Multi-channel RF coil; Parallel imaging