Local Multi-Channel RF Surface Coil versus Body RF Coil Transmission for Cardiac Magnetic Resonance at 3 Tesla: Which Configuration Is Winning the Game?
BACKGROUND
The purpose of this study was to demonstrate the feasibility and efficiency of cardiac MR at 3 Tesla using local four-channel RF coil transmission and benchmark it against large volume body RF coil excitation.


METHODS
Electromagnetic field simulations are conducted to detail RF power deposition, transmission field uniformity and efficiency for local and body RF coil transmission. For both excitation regimes transmission field maps are acquired in a human torso phantom. For each transmission regime flip angle distributions and blood-myocardium contrast are examined in a volunteer study of 12 subjects. The feasibility of the local transceiver RF coil array for cardiac chamber quantification at 3 Tesla is demonstrated.


RESULTS
Our simulations and experiments demonstrate that cardiac MR at 3 Tesla using four-channel surface RF coil transmission is competitive versus current clinical CMR practice of large volume body RF coil transmission. The efficiency advantage of the 4TX/4RX setup facilitates shorter repetition times governed by local SAR limits versus body RF coil transmission at whole-body SAR limit. No statistically significant difference was found for cardiac chamber quantification derived with body RF coil versus four-channel surface RF coil transmission. Our simulation also show that the body RF coil exceeds local SAR limits by a factor of ~2 when driven at maximum applicable input power to reach the whole-body SAR limit.


CONCLUSIONS
Pursuing local surface RF coil arrays for transmission in cardiac MR is a conceptually appealing alternative to body RF coil transmission, especially for patients with implants.
Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.|Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrueck Center for Molecular Medicine, Berlin, Germany.
Oliver
http://orcid.org/0000-0002-3131-936X
O
Weinberger
Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.
Lukas
L
Winter
Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.|Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrueck Center for Molecular Medicine, Berlin, Germany.
Matthias A
MA
Dieringer
Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.
Antje
A
Els
Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.|German Centre for Cardiovascular Research (DZHK), Berlin, Germany.
Celal
C
Oezerdem
MRI.TOOLS GmbH, Berlin, Germany.
Jan
J
Rieger
MRI.TOOLS GmbH, Berlin, Germany.
Andre
A
Kuehne
Medical Metrology Department, Physikalisch Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany.
Antonino M
AM
Cassara
Medical Metrology Department, Physikalisch Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany.
Harald
H
Pfeiffer
Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.
Friedrich
F
Wetterling
Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.|Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrueck Center for Molecular Medicine, Berlin, Germany.|MRI.TOOLS GmbH, Berlin, Germany.
Thoralf
T
Niendorf
D019985:Benchmarking; D004574:Electromagnetic Fields; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D019047:Phantoms, Imaging; D011846:Radio Waves