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Quantification of low-velocity motion using a navigator-echo supported MR velocity-mapping technique: application to intracranial dynamics in volunteers and patients with brain tumours

Author:
  • Ronnie Wirestam
  • Leif Salford
  • C Thomsen
  • Sara Brockstedt
  • B R Persson
  • Freddy Ståhlberg
Publishing year: 1997
Language: English
Pages: 1-11
Publication/Series: Magnetic Resonance Imaging
Volume: 15
Issue: 1
Document type: Journal article
Publisher: Elsevier

Abstract english

Gradient-echo pulse sequences with velocity-encoding gradients of 22.5-25 mT/m, were used for brain-motion and CSF-flow studies. To reduce motion artifacts, a phase-correction technique based on navigator echoes was evaluated. Three patients with right-sided parietal tumours were investigated; one astrocytoma grade III-IV, one astrocytoma grade I-II and one benign meningioma. In healthy volunteers, a maximal brain-tissue velocity of (0.94 +/- 0.26) mm/s (mean +/- 1SD) was observed, which is consistent with previously presented results. The phase correction was proven useful for reduction of artifacts due to external head movements in modulus and phase images, without loss of phase information related to internal motion. The tissue velocity within the astrocytomas was low during the entire cardiac cycle. An abnormally high rostral velocity component was, however, observed in the brain tissue frontal to the astrocytomas. In all patients, an abnormal CSF flow pattern was observed. The study of brain motion may provide further understanding of the effects of tumours and other pathological conditions in the brain. When considering intracranial motion as a source of error in diffusion/perfusion MRI, the present study suggests that a pathology can alter the properties of brain motion and CSF flow considerably, leading to a more complex impact on diffusion/perfusion images.

Keywords

  • Radiology, Nuclear Medicine and Medical Imaging
  • Brain tumour
  • Brain motion
  • Cerebrospinal fluid
  • Magnetic resonance imaging
  • Velocity mapping
  • Phase mapping

Other

Published
  • ISSN: 1873-5894
Freddy Ståhlberg
E-mail: freddy [dot] stahlberg [at] med [dot] lu [dot] se

Professor

Medical Radiation Physics, Lund

+46 46 17 31 19

+46 70 688 31 19

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Professor

Diagnostic Radiology, (Lund)

+46 46 17 70 30

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Project manager

MR Physics

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