Magnetic resonance (MR) examinations of the brain are routinely performed with circularly polarized (CP) head coils. These volume coils are closely shaped around the head of the patient. At best, CP coils provide a signal-to-noise ratio (SNR) gain of √2 compared with non-CP coils. In superconducting systems, they usually have a ‘bird-cage’ configuration. In MR systems where the direction of the B 0 field is oriented perpendicular to the long axis of the body, e.g., open-design resistive or permanent magnet systems, solenoid head coils are used. By diagonally crossing two solenoid wire loops, a CP head coil can be created. Surface coils are rarely used for brain imaging, and are usually reserved for ‘special’ applications: high-resolution imaging of the orbits, or the temporo-mandibular joints (double-doughnut surface coil). A promising new development is the use of phased-array coils to perform high-resolution imagine of the cerebral cortex.
KeywordsIschemia Lymphoma Migraine Tuberculosis Vasculitis
Unable to display preview. Download preview PDF.
- Armed Forces Institute of Pathology (1994) Tumors of the Central Nervous System. Armed Forces Institute of Pathology, Washington, D.C.Google Scholar
- Atlas SW (1996) Magnetic resonance imaging of the brain and spine. Lippincott-Raven, PhiladelphiaGoogle Scholar
- Barkovich JA (1995) Pediatric neuroimaging. Lippincott Raven, PhiladelphiaGoogle Scholar
- Byrd SE, Darling CF, Wilczynski MA (1993) White matter of the brain: maturation and myelination magnetic resonance in infants and children. Neuroimaging Clin North Am 3:247–266Google Scholar
- Castillo M (guest ed) (1998) New techniques in MR neuroimaging. In: Magnetic resonance imaging clinics of North America 1998, vol. 6. Saunders, PhiladelphiaGoogle Scholar
- Hoang TA, Hasso, AN (1994) Intracranial vascular malformations. Neuroimaging Clin North Am 4:823–847Google Scholar
- Jack CR (1995) Magnetic resonance imaging: neuroimaging and anatomy. Neuroimaging Clin North Am 5:597–622Google Scholar
- Lee SH, Rao KCVG, Zimmerman RA (1992) Cranial MRI and CT, 3rd edn. McGraw-Hill, New YorkGoogle Scholar
- Lufkin RB (1998) The MRI manual, 2nd edn. Mosby-Year Book, St. LouisGoogle Scholar
- Osborn AG (1994) Diagnostic neuroradiology. Mosby-Year Book, St. LouisGoogle Scholar
- van der Knaap MS, Valk J (1995) Magnetic resonance of myelin; myelination and myelin disorders. Springer, Berlin Heidelberg New YorkGoogle Scholar