Lectures of Dr. Nikolai Avdievich
Dr. Nikolai Avdievich,
Senior Research Scientist, High-Field MR Center,
Max Planck Institute for Biological Cybernetics, Tubingen,
Institute of Physics, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany
Tuesday, 16.05, room 301/5
Lecture 1. MRI RF Coils: Surface Coils
Matching and tuning of the RF surface coil. Reciprocity theorem, RF coil transmit efficiency, SNR. Q-factor, Optimization of the RF surface coil. Transverse RF surface coils. Tx/Rx linear and quadrature RF coil operations. Components and circuits for RF surface coils.
Lecture 2. RF Coil Components
Transmission lines: VSWR, Reflection coefficient, Impedance, Smith Chart (Introduction), S-parameters, Matching and tuning of the RF surface coil, Components and circuits for RF surface coils, TR Switch, Baluns (Cable traps), Hybrids (Splitters).
Wednesday, 17.05, room 440
Lecture 3. MRI RF Coils: Volume Coils
General method of designing a homogeneous volume coil. Single-mode volume coils. Multiple mode volume coils. Birdcage coil volume coil. TEM volume coil. Half-volume multimode coil. Perturbation method.
Lecture 4. Tx-only/ Rx-only RF Coils and Interfacing to the Scanner
Detuning methods (active, passive), Design of Tx-only (Rx-only) RF surface coils, Design of Tx-only (Rx-only) RF volume coils, Rx-only phased arrays, Preamplifier decoupling, Cable rooting, Interfacing the RF coil to the scanner, Parallel reception, Components and circuits for Tx-only/ Rx-only RF coil.
Lecture 5. Phased Array Decoupling Methods
Decoupling of receive-only (Rx) arrays. Decoupling methods common for both Tx and Rx arrays. Resonant Inductive Decoupling (RID). Amplifier decoupling of Tx arrays. Decoupling (detuning) of Rx and Tx arrays (interarray decoupling). Decoupling b/w 1H- and X-nuclei arrays (double-tuned arrays). Geometrical Decoupling.
Thursday, 18.05, room 301/5
Lecture 6. Phased Array RF Coils
Building block -a single element of an array. Design of Tx-only/ Rx-only arrays (Example). Transmit vs Transceiver arrays. MRI at ultra-high field –advantages and challenges.
Lecture 7. Optimization of the Transmit and Receive Performance of the Transceiver Phased Array for Human Brain Imaging at Ultra-High (> 7T) Fields (UHF)
Maximum local SAR. Decoupling of transceiver array. Various optimization scenarios. Transmit efficiency. Receive performance. Longitudinal coverage. Final Array Design.
Lecture 8. Multi-Tuned Coils
Useful circuits and review (trap design, matching). Double-tuning of the same surface loop. Design ideas and criteria (match, efficiency). Double-tuning of 2 separate surface loops. Various designs of double-tuned coils. Double-tuned volume coils. Double-tuned arrays.