3t ingenia mr system

Four liquid metal coils with a diameter of 105 mm were fabricated with silicone tubes of inner diameters of 0.3, 0.5, 0.8 and 1.0 mm. Their Q_unloaded/Q_loaded was 61/17, 110/16, 152/16 and 166/16, respectively. A reference coil of the same diameter of 105 mm was fabricated from 0.8 mm diameter copper wire. The Q_unloaded/Q_loaded of this copper reference coil was 278/18. All coils were connected to a custom printed circuit board containing tuning, matching, and detuning electronics together with an integrated preamplifier module, with properties similar to standard metal-oxide-semiconductor field-effect transistors^{7 (link)}. Printed circuit boards and components were individual for each coil. The same preamplifier was used in all coils to reduce the effects on the measurements due to variation of noise figure over preamplifiers. Images were acquired on a Philips 3T Ingenia MR system (Philips Healthcare, Best, The Netherlands) using a gradient echo sequence (TR 30 ms, TE 4.7 ms, FA 30°, 1 × 1 × 5 mm³, 1 slice, scan duration 6 s) with the coils conforming to a 120 mm diameter phantom bottle containing a copper sulfate solution emulating MR characteristics of human tissue (770 mg/l CuSO₄ ∙ 5(H₂O), 2000 mg/l NaCl). Following the method proposed by Nordmeyer-Massner et al.,^{7 (link)} pixelwise SNR maps were calculated from imaging data and a dynamic noise scan with no RF and no gradients.

Three different sized phantoms (770 mg/l CuSO₄ ∙ 5(H₂O), 2000 mg/l NaCl) of diameters of 120 mm, 130 mm and 140 mm were used for SNR evaluation of the cylindrical array when stretched. Tuning and matching of the receive array was performed only when attached to the phantom of 120 mm diameter. For the two larger phantoms no further adjustments to tuning and matching were made. Images were acquired on a Philips 3T Ingenia MR system (Philips Healthcare, Best, The Netherlands) using a gradient echo sequence (TR 30 ms, TE 4.7 ms, FA 30°, 1 × 1 × 5 mm³, 1 slice, scan duration 6 s). From images and noise data from a dynamic noise scan, pixelwise SNR and noise correlation maps were calculated^{7 (link)}.

The MR pulse sequence was implemented on a Philips Ingenia 3T MR system (Philips Healthcare, Best, the Netherlands) and was evaluated by phantom studies as well as in-vivo comparison with other approaches.