The results demonstrate the feasibility to characterize prostate cancer metabolism in animals, and now patients using this new 3D dynamic HP MR technique to measure k , the kinetic rate constant of [1- C]pyruvate to [1- C]lactate conversion.

• Although conventional CT is useful for diagnosis of SRMs, it has limitations. • Machine-learning based CT texture analysis facilitate differentiation of small AMLwvf from RCC. • The highest accuracy of SVM-RFE+SMOTE classifier reached 93.9 %. • Texture analysis combined with machine-learning methods might spare unnecessary surgery for AMLwvf.

To our knowledge, this is the first time a chemical shift of the ultrashort-T brain component has been measured in vivo. This chemical shift, at around 1.7 ppm, is similar to the primary resonance of most lipids, indicating that much of the ultrashort-T component observed in vivo arises from bound protons in the myelin phospholipid membranes. Magn Reson Med 80:726-735, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

3 J. Magn. Reson. Imaging 2017;45:167-176.

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Purpose To investigate acute changes in glucose metabolism in liver and kidneys in vivo after a bolus injection of either fructose or glucose, using hyperpolarized [2‐13C]dihydroxyacetone. Methods Spatially registered, dynamic, multi-slice MRS were acquired for the metabolic products of [2-13C]dihydroxyacetone in liver and kidneys. Metabolism was probed in 13 fasted rats at three time points: 0, 70 and 140 minutes. At 60 minutes, rats were injected intravenously with fructose (n=5) or glucose (n=4) at 0.8 g/kg to initiate acute response. Controls (n=4) did not receive a carbohydrate challenge. Results Ten minutes after fructose infusion, levels of [2-13C]phosphoenolpyruvate and [2-13C]glycerol-3-phosphate halved in liver: 51% (P=0.0010) and 47% (P=0.0001) of baseline, respectively. Seventy minutes later, levels returned to baseline. The glucose challenge did not alter the signals significantly, nor did repeated administration of the dihydroxyacetone imaging bolus. In kidneys, no statistically significant changes were detected after sugar infusion other than a 20% increase of the glycerol-3-phosphate signal between 10 and 80 minutes after fructose injection (P=0.0028). Conclusion Hyperpolarized [2-13C]dihydroxyacetone detects a real-time, transient metabolic response of the liver to an acute fructose challenge. Observed effects possibly include ATP depletion and changes in the unlabeled pool sizes of glycolytic intermediates.

Diffusion MRS provides a new method to characterize the ECM degradation processes directly and sensitively. Macromolecule ADCs offer a potentially more sensitive and earlier marker for ECM degradation than the proteoglycan content and T2, and water MR properties during early IVDD. Such diffusion approach offers the possibility to directly monitor ECM integrity and degradation processes in vivo at molecular and microstructural levels in both preclinical and clinical settings.

Effective coil combination methods for human hyperpolarized 13 C spectroscopy multi-channel data had been relatively unexplored. This study implemented and tested several coil combination methods, including 1) the sum-of-squares (SOS), 2) singular value decomposition (SVD), 3) Roemer method by using reference peak area as a sensitivity map (RefPeak), and 4) Roemer method by using ESPIRiT-derived sensitivity map (ESPIRiT). These methods were evaluated by numerical simulation, thermal phantom experiments, and human cancer patient studies. Overall, the SVD, RefPeak, and ESPIRiT methods demonstrated better accuracy and robustness than the SOS method. Extracting complex pyruvate signal provides an easy and excellent approximation of the coil sensitivity map while maintaining valuable phase information of the coil-combined data.