Functional Mr Imaging at 1.5 T

1993 ◽  
Vol 34 (1) ◽  
pp. 101-103 ◽  
Author(s):  
O. Henriksen ◽  
H. B. W. Larsson ◽  
P. Ring ◽  
E. Rostrup ◽  
A. Stensgaard ◽  
...  
Keyword(s):  
Blood Flow ◽  
Motor Cortex ◽  
Mr Imaging ◽  
Preliminary Investigation ◽  
Capillary Blood ◽  
Detectable Change ◽  
Gradient Echo ◽  
Functional Mr Imaging ◽  
Echo Time ◽  
Stimulation Of

A preliminary investigation of the effects of stimulation of the visual and the motor cortex was made on a conventional 1.5 T MR imaging scanner. Both types of activation gave a detectable change in the signal between rest and stimulation using a gradient echo sequence with an echo time of 60 ms. The observed effects were assumed to be caused by variation in the amount of paramagnetic deoxyhemoglobin between stimulation and rest due to local increase of capillary blood flow in the human brain during stimulation.

Functional MR Imaging of the Motor Cortex in Active and Passive Movement: Qualitative and Quantitative Changes

2002 ◽  
Vol 46 (5) ◽  
pp. 425
Author(s):  
Ki Bong Yu ◽  
Myung Kwan Lim ◽  
Hyung Jin Kim ◽  
Jun Soo Byun ◽  
Young Kook Cho ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Mr Imaging ◽  
Passive Movement ◽  
Qualitative And Quantitative ◽  
Functional Mr Imaging ◽  
Quantitative Changes

Functional magnetic resonance imaging of sensory and motor cortex: comparison with electrophysiological localization

1995 ◽  
Vol 83 (2) ◽  
pp. 262-270 ◽  
Author(s):  
Aina Puce ◽  
R. Todd Constable ◽  
Marie L. Luby ◽  
Gregory McCarthy ◽  
Anna C. Nobre ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Magnetic Resonance ◽  
Motor Cortex ◽  
Mr Imaging ◽  
Sensorimotor Cortex ◽  
Functional Magnetic Resonance ◽  
Planar Imaging ◽  
Content Type ◽  
Functional Mr Imaging ◽  
Fine Print

✓ Functional magnetic resonance (MR) imaging was performed using a 1.5-tesla MR system to localize sensorimotor cortex. Six neurologically normal subjects were studied by means of axial gradient-echo images with a motor task and one or more sensory tasks: 1) electrical stimulation of the median nerve; 2) continuous brushing over the thenar region; and 3) pulsed flow of compressed air over the palm and digits. An increased MR signal was observed in or near the central sulcus, consistent with the location of primary sensory and motor cortex. Four patients were studied using echo planar imaging sequences and motor and sensory tasks. Three patients had focal refractory seizures secondary to a lesion impinging on sensorimotor cortex. Activation seen on functional MR imaging was coextensive with the location of the sensorimotor area determined by evoked potentials and electrical stimulation. Functional MR imaging provides a useful noninvasive method of localization and functional assessment of sensorimotor cortex.

MAMMARY OXYGEN TENSION AND THE MILK-EJECTION MECHANISM

1962 ◽  
Vol 23 (4) ◽  
pp. 375-384 ◽  
Author(s):  
B. A. CROSS ◽  
I. A. SILVER
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Mammary Glands ◽  
Capillary Blood ◽  
Milk Ejection ◽  
Electrolytic Lesions ◽  
Ejection Mechanism ◽  
Urethane Anaesthesia ◽  
Surgical Shock ◽  
Stimulation Of

SUMMARY 1. Polarographic recording of pO2 from gold-plated needle electrodes inserted into lactating mammary glands of rabbits under light urethane anaesthesia gave resting values of 15–30 mm. Hg. Expelling the milk from distended glands raised the pO2 level. 2. Myoepithelial contraction (milk ejection) induced by i.v. injection of oxytocin lowered pO2 by an amount depending on the rise in intramammary pressure. 3. Surgical shock, spinal anaesthesia or i.v. injection of adrenaline depressed mammary pO2 and reduced the milk-ejection response to i.v. oxytocin. 4. When mammary pO2 was raised by O2 breathing, or lowered by N2 breathing, the milk-ejection response to i.v. oxytocin was not affected. 5. Electrical stimulation of the lateral and posterior hypothalamic areas reduced mammary pO2 and milk ejection in a way similar to i.v. adrenaline. Bilateral electrolytic lesions in these areas produced a sustained depression of mammary pO2. 6. It is concluded that the pO2 of mammary tissues gives a measure of capillary blood flow and that this, rather than the absolute pO2 level, determines the response of the myoepithelium to circulating oxytocin.

Brain mapping with functional MR imaging: comparison of gradient-echo--based exogenous and endogenous contrast techniques.

Radiology ◽  
1995 ◽  
Vol 194 (3) ◽  
pp. 687-691 ◽  
Author(s):  
V S Mattay ◽  
D R Weinberger ◽  
F A Barrios ◽  
G S Sobering ◽  
K J Kotrla ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Brain Mapping ◽  
Gradient Echo ◽  
Endogenous Contrast ◽  
Functional Mr Imaging

Persistent mirror movements: functional MR imaging of the hand motor cortex.

Radiology ◽  
1997 ◽  
Vol 203 (2) ◽  
pp. 545-552 ◽  
Author(s):  
G L Leinsinger ◽  
D T Heiss ◽  
A G Jassoy ◽  
T Pfluger ◽  
K Hahn ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Mr Imaging ◽  
Mirror Movements ◽  
Functional Mr Imaging
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