Frequency-selective SVD-based magnetic resonance spectroscopy with prior knowledge

We present a novel method for exploiting prior knowledge in magnetic resonance spectroscopy (MRS) based on the frequency-selective SELF-SVD method, which was introduced in P. Stoica et al. (2003). More specifically, we use the common assumption that the magnetic resonance (MR) data is modeled by the superposition of a given number of exponentially damped sinusoids. As an application we consider the ATP (adenosine triphosphate) complex of an MRS signal and we use the fact that the dampings α_k and frequencies ω_k of the peaks of the ATP complex satisfy the following conditions: α_k = α and ω_k = ω + kΔ, where α and ω are unknown and Δ is known. Numerical examples mimicking ₃₁P MRS data are included. The results show the superiority especially in speed of this new approach, which refers to as the FREEK (frequency-selective estimation with prior knowledge) method.