Magnetic Resonance Physics

The magnetic resonance physics unit at Karolinska support diagnostic imaging with diverse techniques, in dynamic, quantitiative and functional MRI. Imaging with magnet strength up to 3T is currently available. The group has extensive connections to academic institutions in Sweden and abroad and a history of international impact in fields such as neurology.

A selection of ongoing projects   

Drug and disease effect on the human brain studied by functional MRI techniques

Investigators:

Love Engström Nordin (1, 2) and Tie-Qiang Li (1, 2)

Affiliations:

Karolinska University Hospital (1) and Karolinska Institutet (2)

Arterial spin labeling (ASL) techniques have become very promising for repetitive, longitudinal and quantitative brain perfusion measurements in MRI. This project consists of a set of studies investigating the potential of pseudo continuous labeling (pCASL), using healthy volunteers and patients with mild traumatic brain injury.

3D MR-phantom to access MR distortions

Investigators:

Torsten Dorniok

Affiliations:

Karolinska University Hospital

This project involves the development of a 3D MR-phantom for the assessment of hardware-related MR distortions (non-linear gradients, eddy currents) using 3D printing methods. This is particular interest for MR in radiation therapy planning, where a high geometric accuracy is essential.

 

Recent publications

Post mTBI fatigue is associated with abnormal brain functional connectivity

Investigators:

Love Engström Nordin (1, 2), Marika Christina Möller (2, 3), Per Juli (2, 4), Aniko Bartfai (2), Farouk Hashim (1, 2) and Tie-Qiang Li (1, 2)

Affiliations:

Karolinska University Hospital (1), Karolinska Institutet (2),  Uppsala University (3) and Stora Sköndal Foundation (4)

This study investigated resting-state functional connectivity before and after performing a 20 minute continuous psychomotor vigilance task (PVT) for patients with chronic post-concussion syndrome, and attempted to find behavioral correlates. The findings suggest that resting-state fMRI measurements may provide a useful indicator of performance potential and of fatigue level in the neural attentional system.

Functional and Structural Alterations in the Cingulate Motor Area Relate to Decreased Fronto-Striatal Coupling in Major Depressive Disorder with Psychomotor Disturbances

Investigators:

Benny Liberg (1, 2), Paul Klauser (1, 3), Ian H. Harding (1, 3), Mats Adler (2), Christoffer Rahm (1, 2), Johan Lundberg (2), Thomas Masterman (2), Caroline Wachtler (1, 2), Tomas Jonsson (4), Maria Kristoffersen-Wiberg (2, 4), Christos Pantelis (1) and Björn Wahlund (5)

Affiliations:

The University of Melbourne (AU) (1), Karolinska Institutet (2), Manash University (AU) (3), Karolinska University Hospital (4) and Swedish University of Agricultural Sciences (5)

Psychomotor disturbances are a classic feature of major depressive disorders. The neural correlates of such disturbances in depression are poorly understood, however in this study using functional and structural MRI, support is given for involvement of the cingulate motor area (CMA) and the putamen.

Shape analysis of the corpus callosum in Alzheimer's disease and frontotemporal lobar degeneration subtypes

Investigators:

Mark Walterfang (1), Eileen Luders (2), Jeffrey C.L. Looi (3, 4), Priya Rajagopalan (2), Dennis Velakoulis (1), Paul M. Thompson (2), Olof Lindberg (4), Per Östberg(4), Love E. Nordin (5), Leif Svensson (5) and Lars-Olof Wahlund (4)

Affiliations:

Royal Melbourne Hospital and University of Melbourne (AU) (1), UCLA School of Medicine (USA) (2), Australian National University Medical School (AU) (3), Karolinska Institutet (4) and Karolinska University Hospital (5)

The morphology of the corpus callosum is a useful indicator of neuronal loss, and a potential discriminator between dementias such as Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD). This study involved 80 subjects and was consistent with the authors' previous findings showing significant cortical and subcortical regional atrophy across FTLD subtypes; results suggest that callosal atrophy patterns differentiate AD from FTLD.

Quantification of severe liver iron overload using MRI offset echoes

Investigators:

Henric Rydén (1) and Mikael Skorpil (1, 2)

Affiliations:

Karolinska University Hospital (1) and Karolinska Institutet (2)

Magnetic resonance imaging (MRI) has become the clinical standard to estimate liver iron overload, the most commonly used technique being a multi-gradient recalled echo sequence (MGRE). We report a case with severe liver hemochromatosis and show the benefit of using an easily implemented MRI offset echo sequence to more accurately estimate liver iron concentration.

Acta Radiol Open. 2015 May 25; 4(5): 2047981614568910