Amide proton transfer (APT) and semi-solid magnetization transfer (ssMT) imaging can predict clinical outcomes in patients with glioma. However, the treatment of brain tumors is accompanied by the deposition of blood products within the tumor area in most cases. For this reason, the objective was to assess whether the diagnostic interpretation of the APT and ssMT is affected by methemoglobin (mHb) and hemosiderin (Hs) depositions at the first follow-up MRI 4 to 6 weeks after the completion of radiotherapy.
View Article and Find Full Text PDFPurpose: The purpose of this study was to compare the potential of asymmetry-based (APTw ), Lorentzian-fit-based (PeakAreaAPT and MT ), and relaxation-compensated (MTR APT and MTR MT) CEST contrasts of the amide proton transfer (APT) and semi-solid magnetization transfer (ssMT) for early response assessment and prediction of progression-free survival (PFS) in patients with glioma.
Methods: Seventy-two study participants underwent CEST-MRI at 3T from July 2018 to December 2021 in a prospective clinical trial four to 6 wk after the completion of radiotherapy for diffuse glioma. Tumor segmentations were performed on T -FLAIR and contrast-enhanced T images.
Background And Purpose: Outcome prediction of patients with glioma early after the completion of radiotherapy represents a major clinical challenge. Previously, the prognostic value of chemical exchange saturation transfer (CEST) imaging has been demonstrated in patients with newly diagnosed glioma. The objective of this study was to assess the potential of amide proton transfer (APT)-, relayed nuclear Overhauser effect (rNOE)- and semi-solid magnetization transfer (ssMT)-imaging according to Zhou et al.
View Article and Find Full Text PDFIn this paper, we investigate depolarization properties of a quartz double-wedge Cornu depolarizer with respect to the generation of spatially unpolarized light in terms of on-average randomly occupied states on the Poincaré sphere. Spatially resolved Stokes parameter measurements yield transformed polarization states and polarization-dispersed characteristic fringes for the Stokes parameters. Their spatial symmetry, the degree of polarization, and spatially integrated Stokes parameters as a function of the aperture-determined input diameter together with a Mueller matrix calculus model confirm the successful generation of equator states incorporating the ensemble of all purely linearly polarized states, thus on spatial average representing unpolarized light.
View Article and Find Full Text PDFWe measure Stokes parameter correlations in analogy to the intensity correlation measurements in the original Hanbury-Brown & Twiss configuration by realizing an experimental setup by combining a Schaefer-Collett or Berry-Gabrielse-Livingston polarimeter with a Hanbury-Brown & Twiss intensity interferometer. We investigate true unpolarized light emitted from a broadband thermal light source, which we realize by an erbium-doped fiber amplifier, thus being an ideal source of true unpolarized light. We find that all Stokes parameter correlations ⟨⟩, ∈{1,2,3} are equal to 0.
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