W(h)ither human cardiac and body magnetic resonance at ultrahigh fields? technical advances, practical considerations, applications, and clinical opportunities

Magnetic Resonance in Med

Graessl

et al. 2015

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103

Section: Electromagnetic Field and Sar Simulationsmentioning

confidence: 99%

Section: Assembly Of a Cardiac Arraymentioning

confidence: 99%

16‐channel bow tie antenna transceiver array for cardiac MR at 7.0 tesla

Oezerdem

Magnetic Resonance in Med

Graessl

et al. 2015

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103

“…In addition to SNR gains and phase noise reduction at UHF (111)(112)(113), improvements are expected by using local multi-channel receive arrays for MR thermometry which demonstrated major SNR benefits over the use of the traditional RF body coil approach and are clinical routine (B0 ≤ 3.0T) (98,(114)(115)(116).…”

Section: Integrated Systems or Thermal Mrmentioning

confidence: 99%

Magnetic resonance thermometry: Methodology, pitfalls and practical solutions

International Journal of Hyperthermia

Oberacker

Paul

et al. 2015

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186

165

Clinically established thermal therapies like thermo ablative approaches or adjuvant hyperthermia treatment rely on accurate thermal dose information for the evaluation and adaptation of the thermal therapy. Intratumoral temperature measurements have been correlated successfully with clinical endpoints. Magnetic resonance imaging is the most suitable technique for non-invasive thermometry avoiding complications related to invasive temperature measurements. Since the advent of MR thermometry two decades ago, numerous MR thermometry techniques have been developed continuously increasing accuracy and robustness for in vivo applications. While this progress was primarily focused on relative temperature mapping, current and future efforts will likely close the gap towards quantitative temperature readings. These efforts are essential to benchmark thermal therapy efficiency, understand temperature related biophysical and physiological processes and to use these insights to set new landmarks for diagnostic and therapeutic applications. With that in mind, this review summarizes and discusses advances in MR thermometry providing practical considerations, pitfalls and technical obstacles constraining temperature measurement accuracy, spatial and temporal resolution in vivo. Established approaches and current trends in thermal therapy hardware are surveyed with respect to potential benefits for MR thermometry.3

“…More than 35.000 7.0 Tesla MR research examinations (1) have already been performed globally, producing valuable data that indicate the value of ultrahigh fields (2)(3)(4)(5)(6)(7)(8). Even if these instruments do not become standard tools in the everyday clinical setting in the very near future, the invaluable new insights they are providing into (patho)physiological processes will be helpful to patients everywhere.…”

Section: Introductionmentioning

confidence: 99%

Electrodynamics and radiofrequency antenna concepts for human magnetic resonance at 23.5 T (1 GHz) and beyond

Niendorf

2016

Magn Reson Mater Phy

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Materials and MethodsElectromagnetic field simulations (EMF) are performed in phantoms with average tissue simulants for dipole antennae using discrete frequencies (300MHz (7.0T) to 3GHz (70.0T)).To advance to a human setup EMF simulations are conducted in anatomical human voxel models of the human head using a 20-element dipole array operating at 1 GHz. ResultsOur results demonstrate that transmission fields suitable for 1 H MR of the human brain can be achieved at 1GHz. An increase in transmit channel density around the human head helps to enhance B1 + in the center of the brain. The calculated relative increase in specific absorption rate (SAR) at 23.5T vs. 7.0T was below 1.4 (in-phase phase setting) and 2.7 (circular polarized phase setting) for the dipole antennae array. ConclusionThe benefits of multi-channel dipole antennae at higher frequencies render MR at 23.5Tfeasible from an electrodynamic standpoint. This very preliminary finding opens the door on further explorations that might be catalyzed into a 20 Tesla class human MR system.2