Media type: E-Article Title: Automatic tuning of flexible interventional RF receiver coils Contributor: Venook, Ross D.; Hargreaves, Brian A.; Gold, Garry E.; Conolly, Steven M.; Scott, Greig C. imprint: Wiley, 2005 Published in: Magnetic Resonance in Medicine Language: English DOI: 10.1002/mrm.20616 ISSN: 0740-3194; 1522-2594 Keywords: Radiology, Nuclear Medicine and imaging Origination: Footnote: Description: <jats:title>Abstract</jats:title><jats:p>Microcontroller‐based circuitry was built and tested for automatically tuning flexible RF receiver coils at the touch of a button. This circuitry is robust to 10% changes in probe center frequency, is in line with the scanner, and requires less than 1 s to tune a simple probe. Images were acquired using this circuitry with a varactor‐tunable 1‐inch flexible probe in a phantom and in an in vitro porcine knee model. The phantom experiments support the use of automatic tuning by demonstrating 30% signal‐to‐noise ratio (SNR) losses for 5% changes in coil center frequency, in agreement with theoretical calculations. Comparisons between patellofemoral cartilage images obtained using a 3‐inch surface coil and the surgically‐implanted 1‐inch flexible coil reveal a worst‐case local SNR advantage of a factor of 4 for the smaller coil. This work confirms that surgically implanted coils can greatly improve resolution in small‐field‐of‐view (FOV) applications, and demonstrates the importance and feasibility of automatically tuning such probes. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.</jats:p>