Mri machine and method for measuring a head area of a patient

Patent metadata

Field	Value
Publication number	US-2018199852-A1
Application number	US-201815868179-A
Country	US
Kind code	A1
Filing date	Jan 11, 2018
Priority date	Jan 13, 2017
Publication date	Jul 19, 2018
Grant date	—

Abstract

Described is an MRI machine for measuring a head area of a patient, comprising at least one primary magnetic field unit, at least one gradient coil assembly, a closed patient opening, at least one excitation coil and at least one receiver coil. In a first region, a closed patient opening of the MRI machine comprises a first inner diameter perpendicular to a center axis of the MRI machine and, in the second region, a second inner diameter, which is arranged parallel to the first inner diameter. The first inner diameter is smaller than the second inner diameter, wherein the first region at least partially comprises the head area of the patient, wherein the second region at least partially comprises a torso area of the patient. The MRI machine is arranged obliquely, wherein, in a z-direction relative to a direction of the gravitational force, the center axis of the MRI machine comprises an angle between 20° and 75°.

First claim

1 . MRI machine for measuring a head area of a patient, comprising at least one primary magnetic field unit, at least one gradient coil assembly, a closed patient opening, at least one excitation coil and at least one receiver coil,
wherein in a first region, a closed patient opening of the MRI machine comprises a first inner diameter (perpendicular to a center axis of the MRI machine, wherein in the second region, a second inner diameter is arranged parallel to the first inner diameter, wherein the first inner diameter is smaller than the second inner diameter, wherein the first region at least partially comprises the head area of the patient, wherein the second region at least partially comprises a torso area of the patient, wherein the MRI machine is arranged obliquely, and wherein the center axis of the MRI machine comprises an angle between 20° and 75° relative to a direction of the gravitational force.

2 . The MRI machine according to claim 1 , wherein the second inner diameter of the second region is disposed along a shoulder axis of the torso area of the patient which is arranged in a coronal manner.

3 . The MRI machine according to claim 1 , wherein a first cross section of the patient opening in the first region and/or a second cross section in the second region comprises a circular shape, an elliptical shape or a rectangular shape.

4 . The MRI machine according to claim 1 , wherein in the first region, the patient opening comprises the first inner diameter is between 250 mm and 650 mm, and in the second region, the second inner diameter is between 500 mm and 800 mm.

5 . The MRI machine according claim 1 , wherein the gradient coil assembly is arranged within the MRI machine around the patient opening, wherein the gradient coil assembly comprises a first gradient coil inner diameter in the first region of the patient opening and a second gradient coil inner diameter in the second region of the patient opening, which is disposed parallel to the first gradient coil inner diameter, wherein the first gradient coil inner diameter is smaller than the second gradient coil inner diameter.

6 . The MRI machine according to claim 1 , wherein the gradient coil assembly is disposed only in the first region and comprises the head area of the patient, and that the second region comprising the torso area is free of the gradient coil assembly.

7 . The MRI machine according to claim 1 , wherein the first region of the patient opening comprises a length of at least 150 mm.

8 . The MRI machine according to claim 1 , wherein the gradient coil assembly comprises a z-gradient coil for a z-direction, wherein the z-gradient coil comprises coil windings which are wound in a cylindrical manner, wherein the distance between the coil windings varies over the length of the z-gradient coil in the z-direction.

9 . The MRI machine according to claim 8 , wherein the winding density of the coil windings of the z-gradient coil is configured symmetrically with respect to a plane of the z-gradient coil, which is arranged perpendicular to the center axis of the MRI machine.

10 . The MRI machine according to claim 8 , wherein the winding density of the coil windings of the z-gradient coil is asymmetrical, wherein the coil windings of the z-gradient coil comprise a higher winding density on a side directed toward a torso of the patient compared to the opposite side that is directed toward the head of the patient.

11 . A Method for positioning a patient relative to an MRI machine according to claim 1 , wherein a patient seat is attached to the MRI machine, wherein the patient seat comprises adjusting means, wherein the patient is positioned on the patient seat and is brought into an imaging position by moving the patient at least partially into the MRI machine by means of the adjusting means along an axis of travel, until the head of the patient is arranged at least partially in the first region of the patient opening of the MRI machine.

12 . The Method according to claim 11 , wherein the adjusting means of the patient seat are mechanically adjusted by a user in order to bring the patient seat into the imaging position.

13 . The Method according to claim 11 , wherein the adjusting means of the patient seat are driven by at least one electric motor and are controlled by means of a control unit, in order to bring the patient seat into the imaging position.

Assignees

• Dentsply Sirona Inc

Inventors

• Hell Erich
• Rasche Volker
• Ulrici Johannes

Classifications

• A61B5/055 Primary

  involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging · CPC title

• G01R33/385

  using gradient magnetic field coils · CPC title

• G01R33/307

  specially adapted for moving the sample relative to the MR system, e.g. spinning mechanisms, flow cells or means for positioning the sample inside a spectrometer · CPC title

• G01R33/381

  using electromagnets · CPC title

• A61B5/0042

  for the brain · CPC title