T1ρ-weighted Dynamic Glucose-enhanced MR Imaging in the Human Brain

Abstract

Purpose To evaluate the ability to detect intracerebral regions of increased glucose concentration at T1ρ-weighted dynamic glucose-enhanced (DGE) magnetic resonance (MR) imaging at 7.0 T. Materials and Methods This prospective study was approved by the institutional review board. Nine patients with newly diagnosed glioblastoma and four healthy volunteers were included in this study from October 2015 to July 2016. Adiabatically prepared chemical exchange-sensitive spin-lock imaging was performed with a 7.0-T whole-body unit with a temporal resolution of approximately 7 seconds, yielding the time-resolved DGE contrast. T1ρ-weighted DGE MR imaging was performed with injection of 100 mL of 20% d-glucose via the cubital vein. Glucose enhancement, given by the relative signal intensity change at T1ρ-weighted MR imaging (DGEρ), was quantitatively investigated in brain gray matter versus white matter of healthy volunteers and in tumor tissue versus normal-appearing white matter of patients with glioblastoma. The median signal intensities of the assessed brain regions were compared by using the Wilcoxon rank-sum test. Results In healthy volunteers, the median signal intensity in basal ganglia gray matter (DGEρ = 4.59%) was significantly increased compared with that in white matter tissue (DGEρ = 0.65%) (P = .028). In patients, the median signal intensity in the glucose-enhanced tumor region as displayed on T1ρ-weighted DGE images (DGEρ = 2.02%) was significantly higher than that in contralateral normal-appearing white matter (DGEρ = 0.08%) (P < .0001). Conclusion T1ρ-weighted DGE MR imaging in healthy volunteers and patients with newly diagnosed, untreated glioblastoma enabled visualization of brain glucose physiology and pathophysiologically increased glucose uptake and may have the potential to provide information about glucose metabolism in tumor tissue. RSNA, 2017 Online supplemental material is available for this article.

d‐glucose weighted chemical exchange saturation transfer (glucoCEST)‐based dynamic glucose enhanced (DGE) MRI at 3T: early experience in healthy volunteers and brain tumor patients

“…Because of the complicated pathology and limited number of cases studied in this initial pilot study, it is difficult to determine the exact pattern of enhancement with glucoCEST. Others also found that regions of DGE and Gd enhancement differed in area . In our previous 7T study, we noticed in 1 patient case that early enhancement corresponded to the Gd‐enhanced ring, whereas later enhancement spread through a larger tumor area not enhanced in the Gd T 1 ‐weighted scan.…”

Dynamic glucose‐enhanced (DGE) MRI in the human brain at 7 T with reduced motion‐induced artifacts based on quantitative R1ρ mapping

“…In this study, two CESL‐based DGE contrast metrics were investigated. First, the R 1ρ ‐weighted dynamic glucose‐enhanced (DGE ρ ) contrast calculated according to Schuenke et al:with S 50ms (t) being the acquired R 1ρ ‐weighted images for the spin‐lock time (TSL) = 50 ms (i.e., TSL 1 ), and S 50ms (ref) being the average of the first 20 S 50ms (t) images. Note, in comparison to the original definition, DGE ρ in Equation is divided by the respective TSL = 50 ms to enable a direct comparison of contrast values (in units of Hz) to the second DGE contrast metric investigated in this study (Equation ).…”

“…Whether glucose in blood vessels, extracellular glucose, or intracellular phosphorylated glucose derivatives are the driving source for the observed DGE contrast remains to be investigated in depth . Furthermore, the applicability for examinations in humans has already been verified in independent pilot studies based on glucoCEST and glucoCESL . However, DGE contrast maps are prone to motion‐induced artifacts because DGE image series consist of data acquired before, during, and after glucose injection.…”

Chemical exchange saturation transfer (CEST) signal intensity at 7T MRI of WHO IV° gliomas is dependent on the anatomic location

“…Additionally, high‐resolution T 2 sequence imaging was performed at 7T MRI . CEST and T 2 image data were coregistered with the "Medical Imaging Interaction Toolkit" (MITK) software, using an automatic multimodal rigid registration algorithm …”