High-field actively detuneable transverse electromagnetic (TEM) coil with low-bias voltage for high-power RF transmission.

High-field actively detuneable transverse electromagnetic (TEM) coil with low-bias voltage for high-power RF transmission. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

High-field actively detuneable transverse electromagnetic (TEM) coil with low-bias voltage for high-power RF transmission. Abstract Text:

Nikolai I Avdievich,Ken Bradshaw,Andrey M Kuznetsov,Hoby P Hetherington,

The design and construction of a 4T (170 MHz) transverse electromagnetic (TEM) actively detuneable quadrature head coil is described. Conventional schemes for active detuning require high negative bias voltages (>300 V) to prevent leakage of RF pulses with amplitudes of 1-2 kW. To extend the power handling capacity and avoid the use of high DC bias voltages, we developed an alternate method of detuning the volume coil. In this method the PIN diodes in the detuning circuits are shorted when the RF volume coil is tuned, and negatively biased with -12 V when the coil is detuned. To preserve the high Q(U)/Q(L) ratio of the TEM coil, we modified the method of Nabetani and Watkins (Proceedings of the 13th Annual Meeting of ISMRM, Kyoto, Japan, 2004, abstract 1574) by utilizing a high-impedance (approximately 200 Omega), lumped-element, quarter-wavelength transformer. A Q(U) of 500 was achieved for the detuneable TEM, such that incorporation of the detuning network had minimal effect (<1 dB) on the performance of the coil in vivo.

High-field actively detuneable transverse electromagnetic (TEM) coil with low-bias voltage for high-power RF transmission. Publishing Authors By Initials

NI Avdievich,K Bradshaw,AM Kuznetsov,HP Hetherington,

For similar equipment and supplies: phantoms, imaging research abstracts see: equipment and supplies: phantoms, imaging research

PUBMED ID PMID:

MEDLINE DATE:

High-field actively detuneable transverse electromagnetic (TEM) coil with low-bias voltage for high-power RF transmission. Journal Published:

PUBLICATION TYPE: Research Support, N.I.H., Extr

Journal: Magnetic resonance in medicine : official journal

VOLUME: 57

Page Numbers: 1190-5

Journal Abbreviation:

ISSN: 0740-3194

DAY: 3

MONTH: Jun

YEAR: 2007

High-field actively detuneable transverse electromagnetic (TEM) coil with low-bias voltage for high-power RF transmission. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 8505245

High-field actively detuneable transverse electromagnetic (TEM) coil with low-bias voltage for high-power RF transmission. Keywords Mesh Terms:

KEYWORDS: Phantoms, Imaging

MESH TERMS: instrumentation

Chemical & Substance for Abstract: High-field actively detuneable transverse electromagnetic (TEM) coil with low-bias voltage for high-power RF transmission. Information

Substance Name:

Registry Number:

Grant and Affiliation Information for High-field actively detuneable transverse electromagnetic (TEM) coil with low-bias voltage for high-power RF transmission.

AFFILIATION: Department of Radiology, Albert Einstein College of Medicine, Bronx, NY, USA. nikolai.avdievich@yale.edu

Country: United States

AGENCY: United States NIBIB

GRANT: R01 EB00473

ACRONYM: EB

MEDLINETA: Magn Reson Med

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

High-field actively detuneable transverse electromagnetic TEM coil with low-bias voltage for high-power RF transmission Related Publications

• 4 T Actively detuneable double-tuned 1H/31P head volume coil and four-channel 31P phased array for human brain spectroscopy.
• 4T split TEM volume head and knee coils for improved sensitivity and patient accessibility.
• Abscisic acid-induced stomatal closure mediated by cyclic ADP-ribose.
• Chronic intermittent but not constant hypoxia decreases NAA/Cr ratios in neonatal mouse hippocampus and thalamus.
• Coxa valga associated with osteo-arthritis.
• Factors influencing neurotrophic effects of electrical stimulation in the deafened developing auditory system.
• Fifteen years' experience with the tuberculin test.
• Generational changes in marriage patterns in the central province of Kenya, 1930-1990.
• High-field actively detuneable transverse electromagnetic (TEM) coil with low-bias voltage for high-power RF transmission.
• How best to hunt for tubercle bacilli.
• Internalization of the Ultra-Thin Ideal: Positive Implicit Associations with Underweight Fashion Models are Associated with Drive for Thinness in Young Women.
• Medical care in Wheatville.
• Parenting and adolescent antisocial behavior and depression: evidence of genotype x parenting environment interaction.
• Q fever treated with erythromycin.
• SENSE imaging with a quadrature half-volume transverse electromagnetic (TEM) coil at 4T.
• SPECIAL OBJECTIVES OF PHYSICAL EDUCATION WITH RELATIONSHIPS TO PUBLIC HEALTH.
• The "Pill" and deep-venous thrombosis.
• The Nonshared Environment in Adolescent Development (NEAD) project: a longitudinal family study of twins and siblings from adolescence to young adulthood.
• The clinical psychologist in the mental hospital.
• The stability of short-term measures of energy regulation: associations with childhood adiposity.
• Traumatic cerebrospinal fluid rhinorrhea and otorrhea, pneumocephalus, and meningitis.