Dynamic phantom for functional magnetic resonance imaging
A dynamic phantom for use with a functional magnetic resonance imaging (fMRI) device is described. In one example, the dynamic phantom includes an outer housing, an inner cylinder including a removable divider, and a gearbox that can rotate the cylinder, all of which are made from fMRI-compatible materials. The divider forms longitudinal compartments inside the cylinder that can each contain a contrast material. When the cylinder contains contrast materials having at least two different concentrations, and a space between the cylinder and the housing also contains a contrast material, rotation of the cylinder produces biomimetic hemodynamic signals that may be detected by the fMRI device.
1. An apparatus for use with a functional magnetic resonance imaging (fMRI) device, comprising:
(a) an fMRI-compatible housing;
(b) an fMRI-compatible support structure, the support structure being cylindrical and concentric with the housing, the support structure being within the housing;
(c) an fMRI-compatible rotor within the housing, the support structure surrounding the rotor;
(d) a first magnetic-resonance-contrast-producing material filling a space between an outer surface of the rotor and an inner surface of the housing;
(e) one or more suitable other magnetic-resonance-contrast-producing materials filling a space within the rotor, such that longitudinal rotation of the rotor produces biomimetic hemodynamic signals that are detected by the fMRI device; and
(f) an fMRI-compatible actuator operatively connected to the rotor.
2. The apparatus as claimed in claim 1 , further comprising:
(g) a power unit capable of powering the actuator;
(h) a control unit operatively connected to the power unit and the actuator;
(i) a position indicator operatively connected to the rotor; and
(j) a feedback unit operatively connected to the position indicator and the control unit.
3. The apparatus as claimed in claim 1 , wherein the housing is substantially cylindrical.
4. The apparatus as claimed in claim 1 , wherein the housing is substantially symmetrical.
5. The apparatus as claimed in claim 1 , wherein the housing is substantially asymmetrical.
6. The apparatus as claimed in claim 5 , wherein the housing is generally anthropomorphic.
7. The apparatus as claimed in claim 1 , wherein the rotor is substantially cylindrical.
8. The apparatus as claimed in claim 7 , wherein the rotor is substantially concentric with the housing.
9. The apparatus as claimed in claim 1 , wherein the actuator is capable of imparting dual rotation to the rotor.
10. The apparatus as claimed in claim 1 , further comprising a removable divider that forms a plurality of longitudinal compartments within the rotor.
11. The apparatus as claimed in claim 10 , wherein the removable divider forms two longitudinal compartments.
12. The apparatus as claimed in claim 10 , wherein the removable divider forms four longitudinal compartments.
13. The apparatus as claimed in claim 12 , wherein the first magnetic-resonance-contrast-producing material has a first concentration and the other magnetic-resonance-contrast-producing materials comprise a second material having a second concentration and a third material having a third concentration, and the second and third materials alternate in each of the four compartments.
14. The apparatus as claimed in claim 13 , wherein the first concentration differs from the second concentration.
15. The apparatus as claimed in claim 13 , wherein the first concentration is differs from the third concentration.
16. The apparatus as claimed in claim 13 , wherein the first concentration differs from the second and third concentrations.
17. An apparatus for use with a functional magnetic resonance imaging (fMRI) device, comprising:
(a) an fMRI-compatible housing;
(b) an fMRI-compatible support structure, the support structure being cylindrical and concentric with the housing, the support structure being within the housing;
(c) an fMRI-compatible rotor that:
is surrounded by the support structure such that a first magnetic-resonance-contrast-producing material is contained in a space between an outer surface of the rotor and an inner surface of the housing; and
is capable of longitudinal rotation that, when the rotor contains one or more suitable other magnetic-resonance-contrast-producing materials, produces biomimetic hemodynamic signals that are detected by the fMRI device; and
(d) an fMRI-compatible actuator operatively connected to the rotor.
18. The apparatus as claimed in claim 17 , further comprising:
(e) a power unit capable of powering the actuator;
(f) a control unit operatively connected to the power unit and the actuator;
(g) a position indicator operatively connected to the rotor; and
(h) a feedback unit operatively connected to the position indicator and the control unit.
19. A method for using a functional magnetic resonance imaging (fMRI) device, comprising:
placing first, second, and third magnetic-resonance-contrast-producing materials within an apparatus comprising:
(a) an fMRI-compatible housing;
(b) an fMRI-compatible support structure, the support structure being cylindrical and concentric with the housing, the support structure being within the housing;
(c) an fMRI-compatible rotor within the housing, the support structure surrounding the rotor, the first magnetic-resonance-contrast-producing material filling a space between an outer surface of the rotor and an inner surface of the housing;
and the second and third magnetic-resonance-contrast-producing materials filling a space within the rotor, such that longitudinal rotation of the rotor produces biomimetic hemodynamic signals that are detected by the fMRI device; and the apparatus further comprising
(d) an fMRI-compatible actuator operatively connected to the rotor;
causing the actuator to rotate the rotor; and
detecting the biomimetic hemodynamic signals.