Synthetic signal injection using a single radiofrequency channel

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Spectroscopy
• Medical Physics

Background:

• Quantitative magnetic resonance (MR) imaging and spectroscopy often employ artificial reference signals (pseudo-signals) for signal conversion.
• Previous methods required simultaneous acquisition of real and pseudo-signals, necessitating a second radiofrequency (RF) channel.

Purpose of the Study:

• To demonstrate that real and pseudo-signals can be acquired separately using a single RF channel without compromising signal fidelity.
• To simplify the conversion of MR signals to concentration units.

Main Methods:

• Validation of the separate acquisition method using in vivo spectroscopy and in vitro imaging.
• Comparison of results from separate acquisition with simultaneous acquisition methods.

Main Results:

• A very strong correlation (r = 0.94; P = 0.02) was observed between in vivo concentrations determined by separate and simultaneous acquisition.
• In vitro measurements confirmed that the separate acquisition method effectively compensates for coil loading variations, similar to simultaneous acquisition.

Conclusions:

• Separate acquisition eliminates the need for a second RF channel, facilitating implementation on single-channel systems.
• This method offers greater flexibility in pseudo-signal design, potentially improving signal-to-noise ratio and reducing concentration conversion variability.