Aims and objectives
Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) allows for indirect detection of diluted molecules via their saturation transfer to the abundant water pool [1-3].
Many different diluted solutes were reported to be detectable with CEST,
including endogenous solutes such as peptides and proteins [3–6],
and injected solutes such as iopamidol [11–13],
or glucose [14–17].
CEST MRI is gaining interest as a molecular MRI technique in a clinical setting. To meet the demand for a fast CEST sequence...
Methods and materials
MRI was performed at 3 T (Prisma,
Siemens Healthcare) in three healthy subjects,
each at a different clinical site: University College London (UCL),
Max Planck Institute (MPI) for Biological Cybernetics in Germany,
and Tel Aviv University (TAU) in Israel. In addition,
one patient with one brain tumor patient with a high-grade glioma was scanned in Tuebingen.
All subjects provided written,
informed consent prior to participation and each study was approved by the local ethics committee.
Snapshot CEST imaging was performed with a 3D gradient echo...
All three sites produced similar CEST contrasts with stable signal distribution over all slices.
APT-weighted images exhibited the expected low contrast in healthy tissues (Figure 2).
Spectrally selective amide- and NOE-CEST maps (Figure 3) showed gray- and white-matter contrast comparable to that reported previously at ultra-high field .
Negligible change in OH-weighted contrast (Figure 4) indicated a stable baseline for future dynamic glucose injection measurements in patients.
The 3 T snapshot CEST protocol generates expected protein CEST contrast signature in the brain tumor (Figure 5):...
At clinical field strengths,
CEST effects are spectrally broadened and lower in magnitude,
and therefore harder to isolate compared to experiments at ultra-high magnetic field strengths. Translation of CEST imaging to clinical field strengths is therefore challenging. In this study,
a fast 3D snapshot CEST imaging sequence optimized for SNR at 3T was tested for clinical feasibility. For three different pre-saturation types,
snapshot CEST produced consistent contrasts at multiple clinical sites,
with results agreement with previous studies [22,
In addition to showing little...
Department of High-Field Magnetic Resonace
Max Planck Institute for Biological Cybernetics
email: [email protected]
Forsen and R.
“Study of Moderately Rapid Chemical Exchange Reactions by Means of Nuclear Magnetic Double Resonance,” J.
Ward et al., “A New Class of Contrast Agents for MRI Based on Proton Chemical Exchange Dependent Saturation Transfer (CEST),” J.
Zhou et al.,
“Using the amide proton signals of intracellular proteins and peptides to detect pH effects in MRI,” Nat.