High‐resolution hyperpolarized metabolic imaging of the rat heart using kk – tt PCA and kk – tt SPARSE

摘要

> The purpose of this work was to increase the resolution of hyperpolarized metabolic imaging of the rat heart with accelerated imaging using k – t principal component analysis ( k – t PCA) and k – t compressed sensing ( k – t SPARSE). Fully sampled in vivo datasets were acquired from six healthy rats after the injection of hyperpolarized [1‐ 13 C]pyruvate. Data were retrospectively undersampled and reconstructed with either k – t PCA or k – t SPARSE. Errors of signal–time curves of pyruvate, lactate and bicarbonate were determined to compare the two reconstruction algorithms for different undersampling factors R . Prospectively undersampled imaging at 1 × 1 × 3.5‐mm 3 resolution was performed with both methods in the same animals and compared with the fully sampled acquisition. k – t SPARSE was found to perform better at R 3, but was outperformed by k – t PCA at R ≥ 4. Prospectively undersampled data were successfully reconstructed with both k – t PCA and k – t SPARSE in all subjects. No significant difference between the undersampled and fully sampled data was found in terms of signal‐to‐noise ratio (SNR) performance and metabolic quantification. Accelerated imaging with both k