A frequency translation approach for multichannel ¹³C spectroscopy

Abstract

Multi-channel receivers are commonplace in MRI, but very few of these receivers are capable of operating over a broad enough bandwidth to accommodate nuclei other than (1)H. While this is fine for imaging, the recent surge in interest in in vivo NMR has created a need for receive arrays to improve the often-poor sensitivity of other nuclei. However, the development of these arrays has been slowed by the scarcity of multi-channel, multinuclear receivers. Frequency translation is a method to solve this by using radiofrequency mixers to convert signals received from multinuclear arrays to the proton frequency, adapting narrow-band receivers to multinuclear use. This method works with a wide variety of nuclei and easily accommodates proton decoupling, a necessity for working with (13)C.

A Review of Non-1H RF Receive Arrays in Magnetic Resonance Imaging and Spectroscopy

“…Historically, most clinical scanners have offered only a single broadband X-nuclei receiver channel, limiting the use of array coils for these applications. Workaround techniques, such as frequency translation [43] , [44] or multiplexing [45] – [47] , have been explored to provide multi-channel capability on systems without multiple broadband receivers. Additionally, clinical scanners which offer multiple broadband receiver channels are slowly becoming more prevalent as the utility of multinuclear studies becomes more apparent.…”