Aaron Kujawa
University College London
Bayesian probabilityIrradiationNuclear Overhauser effectBiomedical engineeringSaturation (chemistry)Magnetic resonance imagingHyperintensityRepeatabilityChemical physicsGaussianSaturation (magnetic)Pulse sequenceChemistryBiological systemField strengthField (physics)Materials scienceRange (statistics)In vivoProstateGrey matterScannerContext (language use)Prostate cancerLesionWhite matterMagnetization transferSignal SensitivityFitting algorithmNuclear medicineRelaxation rateGlucose infusionSaturation transferWater saturationChemical exchangeBody regionMagnetizationMoleculeMathematicsPercentage pointNuclear magnetic resonanceProtonStatistical significanceNuclear magnetic resonance spectroscopyMedicinePulse (signal processing)Coefficient of variationReduction (complexity)
7Publications
3H-index
18Citations
Publications 6
Newest
#1Eleni Demetriou (UCL: University College London)H-Index: 5
#2Aaron Kujawa (UCL: University College London)H-Index: 3
Last. Xavier Golay (UCL: University College London)H-Index: 60
view all 3 authors...
Abstract Within the field of NMR spectroscopy, the study of chemical exchange processes through saturation transfer techniques has a long history. In the context of MRI, chemical exchange techniques have been adapted to increase the sensitivity of imaging to small fractions of exchangeable protons, including the labile protons of amines, amides and hydroxyls. The MR contrast is generated by frequency-selective irradiation of the labile protons, which results in a reduction of the water signal as...
1 CitationsSource
#1Mina Kim (UCL: University College London)H-Index: 3
#2Aaron Kujawa (UCL: University College London)H-Index: 3
Last. Xavier Golay (UCL: University College London)H-Index: 60
view all 12 authors...
PURPOSE: To translate the recently developed PRO-QUEST (Progressive saturation for quantifying exchange rates using saturation times) sequence from preclinical 9.4T to 3T clinical magnetic field strength. METHODS: Numerical simulations were performed to define the optimal saturation flip angles for PRO-QUEST saturation pulses at 3T and demonstrate the effect of a T2 error on the exchange rate (kex ) estimation at various field strengths. Exchange-dependent relaxation rate (Rex ) was measured for...
1 CitationsSource
#1Mina Kim (UCL: University College London)H-Index: 3
#2F Torrealdea (UCLH: University College Hospital)H-Index: 1
Last. Xavier GolayH-Index: 60
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Background: The aim of this study was to translate dynamic glucose enhancement (DGE) body magnetic resonance imaging (MRI) based on the glucose chemical exchange saturation transfer (glucoCEST) signal to a 3 T clinical field strength. Methods: An infusion protocol for intravenous (i.v.) glucose was optimised using a hyperglycaemic clamp to maximise the chances of detecting exchange-sensitive MRI signal. Numerical simulations were performed to define the optimum parameters for glucoCEST measureme...
12 CitationsSource
#1Mina KimH-Index: 3
#2M BattistonH-Index: 4
Last. Xavier GolayH-Index: 60
view all 10 authors...
#1Aaron Kujawa (UCL: University College London)H-Index: 3
#2Mina Kim (UCL: University College London)H-Index: 3
Last. Xavier Golay (UCL: University College London)H-Index: 5
view all 7 authors...
Abstract Fitting a model based on the Bloch-McConnell (BM) equations to Chemical Exchange Saturation Transfer (CEST) spectra allows for the quantification of metabolite concentration and exchange rate as well as simultaneous correction of field inhomogeneity, direct water saturation and magnetization transfer. Employing a Bayesian fitting approach permits the integration of prior information into the analysis to incorporate expected parameter distributions and to prevent over-fitting. However, t...
3 CitationsSource
#1Vincent Evans (UCL: University College London)H-Index: 2
#2F. J. Torrealdea (UCL: University College London)H-Index: 9
Last. David Atkinson (UCL: University College London)H-Index: 68
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BACKGROUND: Chemical exchange saturation transfer (CEST) can potentially support cancer imaging with metabolically derived information. Multiparametric prostate MRI has improved diagnosis but may benefit from additional information to reduce the need for biopsies. PURPOSE: To optimize an acquisition and postprocessing protocol for 3.0 T multipool CEST analysis of prostate data and evaluate the repeatability of the technique. STUDY TYPE: Prospective. SUBJECTS: Five healthy volunteers (age range: ...
8 CitationsSource