In vivo Measurement of Water Self Diffusion in the Human Brain by Magnetic Resonance Imaging

1987 ◽  
Vol 28 (3) ◽  
pp. 353-361 ◽  
Author(s):  
C. Thomsen ◽  
O. Henriksen ◽  
P. Ring
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Tissue Characterization ◽  
Pulse Sequence ◽  
Benign Intracranial Hypertension ◽  
Resonance Imaging ◽  
Self Diffusion ◽  
Brain Water

A new pulse sequence for in vivo diffusion measurements by magnetic resonance imaging (MRI) is introduced. The pulse sequence was tested on phantoms to evaluate the accuracy, reproducibility and inplane variations. The sensitivity of the sequence was tested by measuring the self diffusion coefficient of water with different temperatures. This phantom study showed that the water self diffusion could be measured accurately and that the inplane deviation was less than ±10 per cent. Seven healthy volunteers were studied with a 10 mm thick slice through the lateral ventricles, clear differences between grey and white matter as well as regional differences within the white matter were seen. In two patients with infarction, alternations in water self diffusion were seen in the region of the infarct. Likewise, pronounced changes in brain water self diffusion were observed in a patient with benign intracranial hypertension. The results indicate that brain water self diffusion can be measured in vivo with reasonable accuracy. The clinical examples suggest that diffusion measurements may be clinically useful adding further information about in vivo MR tissue characterization.

scholarly journals An Absolute Measurement of Brain Water Content Using Magnetic Resonance Imaging in Two Focal Cerebral Ischemic Rat Models

2000 ◽  
Vol 20 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Weili Lin ◽  
Ramesh Venkatesan ◽  
Kilichan Gurleyik ◽  
Yong Y. He ◽  
William J. Powers ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Water Content ◽  
Spin Density ◽  
Absolute Measurement ◽  
Brain Water Content ◽  
Resonance Imaging ◽  
Regional Brain ◽  
Brain Water

Magnetic resonance imaging (MRI) was utilized to obtain absolute estimates of regional brain water content (W), and results were compared with those obtained with conventional wet/dry measurements. In total, 31 male Long-Evans rats were studied and divided into two groups based on the surgical procedures used to induce cerebral focal ischemia: suture (n = 18) and three-vessel ligation (TVL; n = 13) groups. Both relative spin density and T1 were extracted from the acquired MR images. After correcting for radiofrequency field inhomogeneities, T2* signal decay, and temperature effects, in vivo regional brain water content, in absolute terms, was obtained by normalizing the measured relative brain spin density of animals to that of a water phantom. A highly linear relationship between MR-estimated brain water content based on the normalized spin density and wet/dry measurements was obtained with slopes of 0.989 and 0.986 for the suture ( r = 0.79) and TVL ( r = 0.83) groups, respectively. Except for the normal subcortex of the TVL group ( P < 0.02) and the normal hemisphere of the suture group ( P < 0.003), no significant differences were observed between MR-estimated and wet/dry measurements of brain water content. In addition, a highly linear relationship between MR-measured R1 (= 1/T1) and 1/W of wet/dry measurements was obtained. However, slopes of the linear regression lines in the two groups were significantly different ( P < 0.02), indicating that different R1 values were associated with the same water content depending on the model. These results show that an absolute measurement of in vivo regional brain water content can be obtained with MRI and potentially serves as a noninvasive means to monitor different therapeutic interventions for the management of brain edema subsequent to stroke and head trauma.

Prolonged bone marrow T1-relaxation in acute leukaemia. In vivo tissue characterization by magnetic resonance imaging

1987 ◽  
Vol 5 (4) ◽  
pp. 251-257 ◽  
Author(s):  
Carsten Thomsen ◽  
Peter Grundtvig Sørensen ◽  
Hans Karle ◽  
Per Christoffersen ◽  
Ole Henriksen
Keyword(s):  
Magnetic Resonance Imaging ◽  
Bone Marrow ◽  
Magnetic Resonance ◽  
Acute Leukaemia ◽  
Tissue Characterization ◽  
Resonance Imaging ◽  
T1 Relaxation

scholarly journals Investigating Sexual Dimorphism of Human White Matter in a Harmonized, Multisite Diffusion Magnetic Resonance Imaging Study

2020 ◽  
Vol 31 (1) ◽  
pp. 201-212 ◽  
Author(s):  
Johanna Seitz ◽  
Suheyla Cetin-Karayumak ◽  
Amanda Lyall ◽  
Ofer Pasternak ◽  
Madhura Baxi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Sex Differences ◽  
White Matter ◽  
Magnetic Resonance ◽  
Imaging Study ◽  
Resonance Imaging ◽  
Sexual Hormones ◽  
Specific Effects ◽  
Weighted Magnetic Resonance Imaging

Abstract Axonal myelination and repair, critical processes for brain development, maturation, and aging, remain controlled by sexual hormones. Whether this influence is reflected in structural brain differences between sexes, and whether it can be quantified by neuroimaging, remains controversial. Diffusion-weighted magnetic resonance imaging (dMRI) is an in vivo method that can track myelination changes throughout the lifespan. We utilize a large, multisite sample of harmonized dMRI data (n = 551, age = 9–65 years, 46% females/54% males) to investigate the influence of sex on white matter (WM) structure. We model lifespan trajectories of WM using the most common dMRI measure fractional anisotropy (FA). Next, we examine the influence of both age and sex on FA variability. We estimate the overlap between male and female FA and test whether it is possible to label individual brains as male or female. Our results demonstrate regionally and spatially specific effects of sex. Sex differences are limited to limbic structures and young ages. Additionally, not only do sex differences diminish with age, but tracts within each subject become more similar to one another. Last, we show the high overlap in FA between sexes, which implies that determining sex based on WM remains open.

P1-198: White matter damage in posterior cortical atrophy assessed in vivo using diffusion tensor magnetic resonance imaging

2012 ◽  
Vol 8 (4S_Part_5) ◽  
pp. P176-P177
Author(s):  
Shiva Keihaninejad ◽  
Hui Zhang ◽  
Tim Shakespeare ◽  
Natalie Ryan ◽  
Ian Malone ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Cortical Atrophy ◽  
Resonance Imaging ◽  
Posterior Cortical Atrophy ◽  
White Matter Damage

A reproducible model of an epidural mass lesion in rodents. Part II: Characterization by in vivo magnetic resonance imaging

2002 ◽  
Vol 97 (6) ◽  
pp. 1419-1423 ◽  
Author(s):  
Martin Bendszus ◽  
Ralf Burger ◽  
Giles Hamilton Vince ◽  
Laszlo Solymosi
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Parietal Lobe ◽  
Mass Lesion ◽  
Resonance Imaging ◽  
Content Type ◽  
Sustained Inflation ◽  
Fine Print

Object. The goal of this study was to characterize a novel epidural space-occupying lesion caused by balloon expansion in rodents by using sequential in vivo magnetic resonance (MR) imaging Methods. Ten Sprague—Dawley rats were intraperitoneally sedated. A trephination was performed over the left parietal cortex to attach a balloon-expansion device, which was secured with dental cement. Measurements were performed using a 1.5-tesla MR imaging device to obtain sequential T2-weighted and diffusion-weighted (DW) sequences in the coronal plane. A three-dimensional, constructed interference in steady state sequence was used for calculation of the balloon volume. The animal's temperature, heartbeat, and the arterial percentage of oxygen saturation were monitored continuously. After a baseline examination had been performed, the balloon was inflated for a 30-minute period until it reached a maximum volume of 0.3 ml; this procedure was followed by a period of sustained inflation lasting 30 minutes, balloon deflation, and a period of reperfusion lasting 3 hours. After perfusion fixation of the animals, morphometric analysis of the lesion size and examination of the percentage of viable neurons in the hippocampus were performed. Magnetic resonance imaging allowed for the precise visualization of the extension and location of the epidural mass lesion, narrowing of the basal cisterns, and development of a midline shift. A white-matter focus of hyperintensity, consistent with brain edema, developed predominantly in the contralateral temporal lobe. During sustained inflation the volume of the balloon did not change and comprised 5 to 7% of total intracranial volume. During the same period the white-matter edema progressed further but no increased signal was revealed on DW images. After balloon deflation the brain reexpanded to the calvaria and imaging signs of raised intracranial pressure subsided. A cortical area of hyperintensity on T2-weighted images developed in the parietal lobe in the region of the former balloon compression. This area appeared bright on DW images, a finding that corresponded to an early cytotoxic edema. After deflation white-matter vasogenic edema in the temporal lobes regressed within 3 hours after reperfusion. The cortical edema in the parietal lobe and the ipsilateral basal ganglia became sharply demarcated. The histopathological results (that is, the extent of tissue damage) corresponded with findings of the authors' companion investigation, which appears in this issue. Conclusions. Magnetic resonance imaging allows for a precise and sequential in vivo monitoring of a space-occupying epidural mass lesion and visualizes the time course of vasogenic and cytotoxic brain edema. This rodent model of an epidural mass lesion proved to be reproducible.

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