Low-Noise Active Decoupling Circuit and its Application to 13C Cryogenic RF Coils at 3T

We analyze the loss contributions in a small, 50-mm-diameter receive-only coil for carbon-13 (13C) magnetic resonance imaging at 3 T for 3 different circuits, which, including active decoupling, are compared in terms of their Q-factors and signal-to-noise ratio (SNR). The results show that a circuit using unsegmented tuning and split matching capacitors can provide >20% SNR enhancement at room temperature compared with that using more traditional designs. The performance of the proposed circuit was also measured when cryogenically cooled to 105 K, and an additional 1.6-fold SNR enhancement was achieved on a phantom. The enhanced circuit performance is based on the low capacitance needed to match to 50 Ω when coil losses are low, which significantly reduces the proportion of the current flowing through the matching network and therefore minimizes this loss contribution. This effect makes this circuit particularly suitable for receive-only cryogenic coils and/or small coils for low-gamma nuclei

3D myocardial perfusion quantification using hyperpolarized HP001

We propose a 3D gradient echo sequence with hyperpolarized HP001 as contrast agent for whole heart myocardial perfusion quantification. The estimated perfusion values are correlated with the perfusion values estimated from dynamic contrast enhanced (DCE)-MRI

A constrained decomposition method for myocardial perfusion quantification using hyperpolarized MRI

As an alternative to Gadolinium, metabolically inert hyperpolarized contrast agents have been used in perfusion studies. For myocardial perfusion measurements, it is challenging to reliably obtain perfusionrelated signals due to partial volume effects. We propose a constrained decomposition approach, enforcing prior knowledge of the residue function being temporally decreasing. The method is capable of separating the arterial and perfusion components and the quantified perfusion map is not visibly affected by partial volume effects