9.4 Tesla

Diffusion Imaging

Nuclear Magnetic Resonance Diffusion Imaging


Diffusion tensor imaging (DTI) investigates none-invasively the cellular architecture by probing the water molecules displacement due to thermal motion. Diffusion information are described by an ellipsoid, representing the water molecule apparent diffusion in three dimension (Ell.). Several metrics can be derived with the mean diffusivity (MD), the axial diffusivity (AD), the radial diffusivity (RD) given in 10-3 mm2/s and the fractional anisotropy (FA) representing a normalized ratio between AD and RD.

References
– Kunz N, Sizonenko S., Hüppi P, Gruetter R, van de Looij Y (2013) “Investigation of field and diffusion time dependence of the diffusion-weighted signal at ultrahigh magnetic fields”, NMR in biomed, doi: 10.1002/nbm.2945
– van de Looij Y, Lodygensky GA, Dean J, Lazeyras F, Hagberg H, Kjellmer I, Mallard C, Hüppi PS, Sizonenko SV (2012) “High-field diffusion tensor imaging characterization of cerebral white matter injury in lipopolysaccharide-exposed fetal sheep”, Pediatr Res. 72(3):285-92. doi: 10.1038/pr.2012.72.
 

1H spectroscopy installation, including CSI

In vivo 1H MRS

Reference
Cudalbu C. (2012) In vivo studies of brain metabolism in animal models of Hepatic Encephalopathy using (1)H Magnetic Resonance Spectroscopy, Metab Brain Dis. DOI 10.1007/s11011-012-9368-9

In vivo 13C MRS

 

Reference
Lanz B, Duarte JMN, Kunz N, Mlynárik V, Gruetter R, Cudalbu C. (2012) Which prior knowledge? Quantification of in vivo brain 13C MR spectra following 13C glucose infusion using AMARES. Magnetic Resonance in Medicine, doi: 10.1002/mrm.24406

In vivo 19F MRI

In vivo 19F-CMR of myocarditis. (A) 1H CMR slice at the base of the heart of a mouse with disease score 3; RV, LV: right & left ventricles; Lu: lung; Li: liver (B) 19F-CMR; signal can be observed at the myocardium (solid arrow) and at the liver (dotted arrow). (C) Fusion of A & B: 19F signal co-localizes with subepicardial layer of the LV anterior wall, RV free wall (arrow) and liver (dotted arrow). (D) An animal with disease score 4. The 19F signal is spread over the majority of the ventricles with a subepicardial 19F signal in the inferior wall of the LV (arrowhead). (E) Animal with disease score 2 with a relatively small patch of 19F signal (arrow). (F) Healthy control, with 19F signal only in the liver (dotted arrow).

3D ex vivo CMR of a mouse heart with myocarditis. (A) 1H long-axis MR image of the heart. (B) 19F MR image at same location with the same resolution of 112x112x224μm. (C) Fusion image showing 19F signal in the subepicardial layer of the LV. Blue lines indicate location of the orthogonal images in (D&E). Solid, dashed and dotted frames correspond to image orientations shown by the corresponding cross-sectional line patterns.
                                                                                                                                                        Reference
van Heeswijk RB, De Blois J, Kania G, Gonzales C, Blyszczuk P, Stuber M, Eriksson U, Schwitter J. (2013) Circ Cardiovasc Imaging. 6: 277-284.
 

In vivo 15N MRS

 

A) Representative in vivo 15N spectra acquired in the rat brain during 15N ammonium chloride infusion; B) Neuroglial two-compartment metabolic model for [5‐ 15N]Gln and [2‐ 15N]Gln+Glu; C) The time courses and corresponding fits of total Gln, [5‐ 15N]Gln and [2‐ 15N]Gln+Glu from one rat (duration of ammonium chloride infusion 7 hours).

Reference
Cudalbu C, Lanz B, Duarte JM, Morgenthaler FD, Pilloud Y, Mlynárik V, Gruetter R. (2012) J Cereb Blood Flow Metab. 32(4):696‐708