@article{HuberHaaseGleich2017, author = {Huber, Stephan and Haase, Axel and Gleich, Bernhard}, title = {Analysis of 2D NMR relaxation data using Chisholm approximations}, volume = {2017}, journal = {Journal of Magnetic Resonance}, number = {281}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1096-0856}, doi = {https://doi.org/10.1016/j.jmr.2017.05.006}, pages = {66 -- 74}, year = {2017}, language = {en} } @article{GomezDamianSperlJanichetal.2014, author = {G{\´o}mez Dami{\´a}n, Pedro A. and Sperl, Jonathan I. and Janich, Martin A. and Khegai, Oleksandr and Wiesinger, Florian and Glaser, Steffen J. and Haase, Axel and Schwaiger, Markus and Schulte, Rolf F. and Menzel, Marion Irene}, title = {Multisite Kinetic Modeling of 13C Metabolic MR Using [1-13C]Pyruvate}, volume = {2014}, pages = {871619}, journal = {Radiology Research and Practice}, publisher = {Hindawi}, address = {New York}, issn = {2090-195X}, doi = {https://doi.org/10.1155/2014/871619}, year = {2014}, abstract = {Hyperpolarized13C imaging allows real-timein vivomeasurements of metabolite levels. Quantification of metabolite conversion between [1-13C]pyruvate and downstream metabolites [1-13C]alanine, [1-13C]lactate, and [13C]bicarbonate can be achieved through kinetic modeling. Since pyruvate interacts dynamically and simultaneously with its downstream metabolites, the purpose of this work is the determination of parameter values through a multisite, dynamic model involving possible biochemical pathways present in MR spectroscopy. Kinetic modeling parameters were determined by fitting the multisite model to time-domain dynamic metabolite data. The results for different pyruvate doses were compared with those of different two-site models to evaluate the hypothesis that for identical data the uncertainty of a model and the signal-to-noise ratio determine the sensitivity in detecting small physiological differences in the target metabolism. In comparison to the two-site exchange models, the multisite model yielded metabolic conversion rates with smaller bias and smaller standard deviation, as demonstrated in simulations with different signal-to-noise ratio. Pyruvate dose effects observed previously were confirmed and quantified through metabolic conversion rate values. Parameter interdependency allowed an accurate quantification and can therefore be useful for monitoring metabolic activity in different tissues.}, language = {en} } @article{HuberMinStaatetal.2019, author = {Huber, Stephan and Min, Changwook and Staat, Christoph and Oh, Juhyun and Castro, Cesar and Haase, Axel and Weissleder, Ralph and Gleich, Bernhard and Lee, Hakho}, title = {Multichannel digital heteronuclear magnetic resonance biosensor}, volume = {2019}, journal = {Biosensors and Bioelectronics}, number = {126}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-4235}, doi = {https://doi.org/10.1016/j.bios.2018.10.052}, pages = {240 -- 248}, year = {2019}, language = {en} } @article{CoelloHafalirNoeskeetal.2019, author = {Coello, Eduardo and Hafalir, Fatih S. and Noeske, Ralph and Menzel, Marion Irene and Haase, Axel and Menze, Bjoern H. and Schulte, Rolf F.}, title = {Overdiscrete echo-planar spectroscopic imaging with correlated higher-order phase correction}, volume = {84}, journal = {Magnetic Resonance in Medicine}, number = {1}, publisher = {Wiley}, address = {Hoboken}, issn = {1522-2594}, doi = {https://doi.org/10.1002/mrm.28105}, pages = {11 -- 24}, year = {2019}, language = {en} } @article{WuMulderBaronetal.2020, author = {Wu, Mingming and Mulder, Hendrik T. and Baron, Paul and Coello, Eduardo and Menzel, Marion Irene and van Rhoon, Gerard C. and Haase, Axel}, title = {Correction of motion-induced susceptibility artifacts and B0 drift during proton resonance frequency shift-based MR thermometry in the pelvis with background field removal methods}, volume = {84}, journal = {Magnetic Resonance in Medicine}, number = {5}, publisher = {Wiley}, address = {Hoboken}, issn = {1522-2594}, doi = {https://doi.org/10.1002/mrm.28302}, pages = {2495 -- 2511}, year = {2020}, abstract = {Purpose The linear change of the water proton resonance frequency shift (PRFS) with temperature is used to monitor temperature change based on the temporal difference of image phase. Here, the effect of motion-induced susceptibility artifacts on the phase difference was studied in the context of mild radio frequency hyperthermia in the pelvis. Methods First, the respiratory-induced field variations were disentangled from digestive gas motion in the pelvis. The projection onto dipole fields (PDF) as well as the Laplacian boundary value (LBV) algorithm were applied on the phase difference data to eliminate motion-induced susceptibility artifacts. Both background field removal (BFR) algorithms were studied using simulations of susceptibility artifacts, a phantom heating experiment, and volunteer and patient heating data. Results Respiratory-induced field variations were negligible in the presence of the filled water bolus. Even though LBV and PDF showed comparable results for most data, LBV seemed more robust in our data sets. Some data sets suggested that PDF tends to overestimate the background field, thus removing phase attributed to temperature. The BFR methods even corrected for susceptibility variations induced by a subvoxel displacement of the phantom. The method yielded successful artifact correction in 2 out of 4 patient treatment data sets during the entire treatment duration of mild RF heating of cervical cancer. The heating pattern corresponded well with temperature probe data. Conclusion The application of background field removal methods in PRFS-based MR thermometry has great potential in various heating applications and body regions to reduce motion-induced susceptibility artifacts that originate outside the region of interest, while conserving temperature-induced PRFS. In addition, BFR automatically removes up to a first-order spatial B0 drift.}, language = {en} } @article{WuMulderZuretal.2018, author = {Wu, Mingming and Mulder, Hendrik T. and Zur, Yuval and Lechner-Greite, Silke and Menzel, Marion Irene and Paulides, Margarethus M. and Rhoon, Gerard C. van and Haase, Axel}, title = {A phase-cycled temperature-sensitive fast spin echo sequence with conductivity bias correction for monitoring of mild RF hyperthermia with PRFS}, volume = {32}, journal = {Magnetic Resonance Materials in Physics, Biology and Medicine}, number = {3}, publisher = {Springer}, address = {Heidelberg}, issn = {1352-8661}, doi = {https://doi.org/10.1007/s10334-018-0725-5}, pages = {369 -- 380}, year = {2018}, language = {en} } @article{SprengerSperlFernandezetal.2016, author = {Sprenger, Tim and Sperl, Jonathan I. and Fernandez, Brice and Haase, Axel and Menzel, Marion Irene}, title = {Real valued diffusion-weighted imaging using decorrelated phase filtering}, volume = {77}, journal = {Magnetic Resonance in Medicine}, number = {2}, publisher = {Wiley}, address = {Hoboken}, issn = {1522-2594}, doi = {https://doi.org/10.1002/mrm.26138}, pages = {559 -- 570}, year = {2016}, language = {en} } @article{SprengerSperlFernandezetal.2016, author = {Sprenger, Tim and Sperl, Jonathan I. and Fernandez, Brice and Golkov, Vladimir and Eidner, Ines and S{\"a}mann, Philipp G. and Czisch, Michael and Tan, Ek Tsoon and Hardy, Christopher J. and Marinelli, Luca and Haase, Axel and Menzel, Marion Irene}, title = {Bias and precision analysis of diffusional kurtosis imaging for different acquisition schemes}, volume = {76}, journal = {Magnetic Resonance in Medicine}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {1522-2594}, doi = {https://doi.org/10.1002/mrm.26008}, pages = {1684 -- 1696}, year = {2016}, language = {en} } @article{ScholzJanichKoellischetal.2014, author = {Scholz, David Johannes and Janich, Martin A. and Koellisch, Ulrich and Schulte, Rolf F. and Ardenkjaer-Larsen, Jan H. and Frank, Annette and Haase, Axel and Schwaiger, Markus and Menzel, Marion Irene}, title = {Quantified pH imaging with hyperpolarized 13C-bicarbonate}, volume = {73}, journal = {Magnetic Resonance in Medicine}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {1522-2594}, doi = {https://doi.org/10.1002/mrm.25357}, pages = {2274 -- 2282}, year = {2014}, language = {en} } @article{KoellischLaustsenNorlingeretal.2015, author = {Koellisch, Ulrich and Laustsen, Christoffer and N{\o}rlinger, Thomas S. and {\O}stergaard, Jakob Appel and Flyvbjerg, Allan and Gringeri, Concetta V. and Menzel, Marion Irene and Schulte, Rolf F. and Haase, Axel and St{\o}dkilde-J{\o}rgensen, Hans}, title = {Investigation of metabolic changes in STZ-induced diabetic rats with hyperpolarized [1-13C]acetate}, volume = {3}, pages = {e12474}, journal = {Physiological Reports}, number = {8}, publisher = {Wiley}, address = {Weinheim}, issn = {2051-817X}, doi = {https://doi.org/10.14814/phy2.12474}, year = {2015}, abstract = {In the metabolism of acetate several enzymes are involved, which play an important role in free fatty acid oxidation. Fatty acid metabolism is altered in diabetes patients and therefore acetate might serve as a marker for pathological changes in the fuel selection of cells, as these changes occur in diabetes patients. Acetylcarnitine is a metabolic product of acetate, which enables its transport into the mitochondria for energy production. This study investigates whether the ratio of acetylcarnitine to acetate, measured by noninvasive hyperpolarized [1-13C]acetate magnetic resonance spectroscopy, could serve as a marker for myocardial, hepatic, and renal metabolic changes in rats with Streptozotocin (STZ)-induced diabetes in vivo. We demonstrate that the conversion of acetate to acetylcarnitine could be detected and quantified in all three organs of interest. More interestingly, we found that the hyperpolarized acetylcarnitine to acetate ratio was independent of blood glucose levels and prolonged hyperglycemia following diabetes induction in a type-1 diabetes model.}, language = {en} }