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Triple-tuned birdcage and single-tuned dipole array for quadri-nuclear head MRI at 7 T

Paška, Jan; Wang, Bili; Chen, Anna M; Madelin, Guillaume; Brown, Ryan
PURPOSE/OBJECTIVE:The purpose of this work was to design and build a coil for quadri-nuclear MRI of the human brain at 7 T. METHODS: RESULTS: CONCLUSION/CONCLUSIONS:While the SNR of the quadruple tuned coil was significantly lower than dual- and single-tuned reference coils, it represents a step toward truly simultaneous quadri-nuclear measurements.
PMID: 38116692
ISSN: 1522-2594
CID: 5612402

Three-row MRI receive array with remote circuitry to preserve radiation transparency

Lakshmanan, Karthik; Wang, Bili; Walczyk, Jerzy; Collins, Christopher M; Brown, Ryan
PMID: 38537307
ISSN: 1361-6560
CID: 5644962

Extended and weightbearing wrist 3-T MRI using a novel harness and flexible 24-channel glove coil to evaluate carpal kinematics: a pilot study in 10 volunteers

Wang, Bili; Walczyk, Jerzy; Ahmed, Mohammad; Elkowitz, Stuart; Daniels, Steven; Brown, Ryan; Burke, Christopher J
BACKGROUND:Wrist pain in the extended or extended weightbearing positions may be incompletely evaluated using standard magnetic resonance imaging (MRI) with standard rigid clamshell coils in the neutral position. PURPOSE/OBJECTIVE:To evaluate a flexible 24-channel glove coil and harness when imaging the wrist in neutral, dorsally extended, and weightbearing positions. MATERIAL AND METHODS/METHODS:Ten wrists in 10 asymptomatic volunteers (mean age = 29 years) were scanned. Participants underwent 3-T MRI using the harness and flexible glove coil, acquiring sagittal turbo spin echo (TSE) and half-Fourier acquisition single-shot turbo spin echo (HASTE) pulse sequences. Static TSE images were obtained in neutral, extended, and weightbearing positions using proton density parameters and independently evaluated by two radiologists for: dorsal radiocarpal ligament thickness; radiocapitate, radiolunate, and capitatolunate angles; palmar translation of the lunate on the radius; angulation of the extensor tendons; and distance from the distal extensor retinaculum to Lister's tubercle. Cine HASTE images were dynamically acquired between neutral-maximum extension to measure the radiocapitate angle. RESULTS: < 0.01). CONCLUSION/CONCLUSIONS:Significant increases in dorsal radiocarpal ligament thickness, articular and tendon angulations occur during wrist extension, that further increase with dorsal weightbearing.
PMID: 37470466
ISSN: 1600-0455
CID: 5535952

Magnetic resonance imaging-based assessment of in vivo cartilage biomechanics

Chapter by: Menon, Rajiv G.; Brown, Ryan; Regatte, Ravinder R.
in: Cartilage Tissue and Knee Joint Biomechanics: Fundamentals, Characterization and Modelling by
[S.l.] : Elsevier, 2023
pp. 163-171
ISBN: 9780323907217
CID: 5615722

A flexible MRI coil based on a cable conductor and applied to knee imaging

Wang, Bili; Siddiq, Syed S; Walczyk, Jerzy; Bruno, Mary; Khodarahmi, Iman; Brinkmann, Inge M; Rehner, Robert; Lakshmanan, Karthik; Fritz, Jan; Brown, Ryan
Flexible radiofrequency coils for magnetic resonance imaging (MRI) have garnered attention in research and industrial communities because they provide improved accessibility and performance and can accommodate a range of anatomic postures. Most recent flexible coil developments involve customized conductors or substrate materials and/or target applications at 3 T or above. In contrast, we set out to design a flexible coil based on an off-the-shelf conductor that is suitable for operation at 0.55 T (23.55 MHz). Signal-to-noise ratio (SNR) degradation can occur in such an environment because the resistance of the coil conductor can be significant with respect to the sample. We found that resonating a commercially available RG-223 coaxial cable shield with a lumped capacitor while the inner conductor remained electrically floating gave rise to a highly effective "cable coil." A 10-cm diameter cable coil was flexible enough to wrap around the knee, an application that can benefit from flexible coils, and had similar conductor loss and SNR as a standard-of-reference rigid copper coil. A two-channel cable coil array also provided good SNR robustness against geometric variability, outperforming a two-channel coaxial coil array by 26 and 16% when the elements were overlapped by 20-40% or gapped by 30-50%, respectively. A 6-channel cable coil array was constructed for 0.55 T knee imaging. Incidental cartilage and bone pathologies were clearly delineated in T1- and T2-weighted turbo spin echo images acquired in 3-4 min with the proposed coil, suggesting that clinical quality knee imaging is feasible in an acceptable examination timeframe. Correcting for T1, the SNR measured with the cable coil was approximately threefold lower than that measured with a 1.5 T state-of-the-art 18-channel coil, which is expected given the threefold difference in main magnetic field strength. This result suggests that the 0.55 T cable coil conductor loss does not deleteriously impact SNR, which might be anticipated at low field.
PMID: 36056131
ISSN: 2045-2322
CID: 5332272

A 13C/31P surface coil to visualize metabolism and energetics in the rodent brain at 3 Tesla

Vaidya, Manushka V; Zhang, Bei; Hong, DongHyun; Brown, Ryan; Batsios, Georgios; Viswanath, Pavithra; Paska, Jan; Wulf, Gerburg; Grant, Aaron K; Ronen, Sabrina M; Larson, Peder E Z
PURPOSE/OBJECTIVE:P MRS was carried out for a healthy rat brain. METHODS:P spectra were obtained in a single scan session using 1D slice selective acquisitions. RESULTS:P MRS. CONCLUSIONS:The coil enables obtaining complementary information within a scan session, thus reducing the number of trials and minimizing biological variability for studies of metabolism and bioenergetics.
PMID: 36075133
ISSN: 1096-0856
CID: 5337132

Simultaneous 3D acquisition of 1 H MRF and 23 Na MRI

Yu, Zidan; Hodono, Shota; Dergachyova, Olga; Hilbert, Tom; Wang, Bili; Zhang, Bei; Brown, Ryan; Sodickson, Daniel K; Madelin, Guillaume; Cloos, Martijn A
PURPOSE/OBJECTIVE:, and proton density) and sodium density weighted images over the whole brain. METHODS:were evaluated in phantoms. Finally, in vivo application of the method was demonstrated in five healthy subjects. RESULTS:values measured using our method were lower than the results measured by other conventional techniques. CONCLUSIONS:
PMID: 34971454
ISSN: 1522-2594
CID: 5108342

Twenty-four-channel high-impedance glove array for hand and wrist MRI at 3T

Zhang, Bei; Wang, Bili; Ho, Justin; Hodono, Shota; Burke, Christopher; Lattanzi, Riccardo; Vester, Markus; Rehner, Robert; Sodickson, Daniel; Brown, Ryan; Cloos, Martijn
PURPOSE/OBJECTIVE:To present a novel 3T 24-channel glove array that enables hand and wrist imaging in varying postures. METHODS:The glove array consists of an inner glove holding the electronics and an outer glove protecting the components. The inner glove consists of four main structures: palm, fingers, wrist, and a flap that rolls over on top. Each structure was constructed out of three layers: a layer of electrostatic discharge flame-resistant fabric, a layer of scuba neoprene, and a layer of mesh fabric. Lightweight and flexible high impedance coil (HIC) elements were inserted into dedicated tubes sewn into the fabric. Coil elements were deliberately shortened to minimize the matching interface. Siemens Tim 4G technology was used to connect all 24 HIC elements to the scanner with only one plug. RESULTS:The 24-channel glove array allows large motion of both wrist and hand while maintaining the SNR needed for high-resolution imaging. CONCLUSION/CONCLUSIONS:In this work, a purpose-built 3T glove array that embeds 24 HIC elements is demonstrated for both hand and wrist imaging. The 24-channel glove array allows a great range of motion of both the wrist and hand while maintaining a high SNR and providing good theoretical acceleration performance, thus enabling hand and wrist imaging at different postures to extract kinematic information.
PMID: 34971464
ISSN: 1522-2594
CID: 5108352

Transcranial Photobiomodulation Modulates Metabolism in the Human Brain as Measured by Magnetic Resonance Spectroscopy

Chapter by: Walsh, Kevin A.; Malave, Amilcar; Brown, Ryan; Dmochowski, Jacek
in: Proceedings of the International Astronautical Congress, IAC by
[S.l.] : International Astronautical Federation, IAF, 2022
pp. ?-?
CID: 5619892

A radially interleaved sodium and proton coil array for brain MRI at 7 T

Wang, Bili; Zhang, Bei; Yu, Zidan; Ianniello, Carlotta; Lakshmanan, Karthik; Paska, Jan; Madelin, Guillaume; Cloos, Martijn; Brown, Ryan
The objective of the current study was to design and build a dual-tuned coil array for simultaneous 23 Na/1 H MRI of the human brain at 7 T. Quality factor, experimental B1 + measurements, and electromagnetic simulations in prototypes showed that setups consisting of geometrically interleaved 1 H and 23 Na loops performed better than or similar to 1 H or 23 Na loops in isolation. Based on these preliminary findings, we built a transmit/receive eight-channel 23 Na loop array that was geometrically interleaved with a transmit/receive eight-channel 1 H loop array. We assessed the performance of the manufactured array with mononuclear signal-to-noise ratio (SNR) and B1 + measurements, along with multinuclear magnetic resonance fingerprinting maps and images. The 23 Na array within the developed dual-tuned device provided more than 50% gain in peripheral SNR and similar B1 + uniformity and coverage as a reference birdcage coil of similar size. The 1 H array provided good B1 + uniformity in the brain, excluding the cerebellum and brain stem. The integrated 23 Na and 1 H arrays were used to demonstrate truly simultaneous quantitative 1 H mapping and 23 Na imaging.
PMID: 34476861
ISSN: 1099-1492
CID: 5011792