JP3168634B2 - Method of creating 3D model of neural activity site - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for creating a three-dimensional model of a nerve activity part to be an estimation area when estimating the position, size, and direction of a biological activity current source, for example. Note that this three-dimensional model is also used in the field of research on brain function and at the time of various diagnoses.

[0002]

2. Description of the Related Art When an external stimulus such as light or sound is applied to a living body, a signal (active current) is generated in a sensory nerve.
The magnetic field formed by this biological activity current is referred to as SQUI
The measurement is performed with a sensor using D (Superconducting Quantum Interference Dvice), and the position, size, and direction of the biological activity current source are estimated from the measurement data. The estimated life activity current source (hereinafter simply abbreviated as a current source) is displayed on a tomographic image inside the body taken by an X-ray CT apparatus, an MRI apparatus, or the like, and is used to specify a physical position of an affected part or the like. You.

A general method for estimating the position, magnitude, and direction of a current source is to assume a large number of current sources of an arbitrary size and an arbitrary direction at an arbitrary position in the brain of a living body, Magnetic field distribution data formed by the source is obtained by numerical calculation. Then, a square error between the calculated magnetic field distribution data and the magnetic field distribution data of the living body actually measured by the SQUID sensor is obtained, and a biological activity current source corresponding to the magnetic field distribution data with the minimum square error is obtained.

[0004] At this time, if a large number of current sources are assumed for all regions of the brain, the calculation amount of the magnetic field distribution data becomes enormous and the estimation time is considerably consumed. Therefore, it is often the case that a certain region in the brain is designated and the current source is estimated in that region. When specifying the area, first
A method is adopted in which a three-dimensional model of the brain is created and displayed on a monitor display, and an area in the brain corresponding to the surface of the head on which the SQUID sensor is installed is specified for the three-dimensional model.

[0005]

However, the installation location of the SQUID sensor is almost arbitrary in most cases.
The region of the brain corresponding to the surface of the head where the UID sensor is installed does not always have the bioactive current source. The magnetic field distribution data measured at the time of estimation is based on the current source generated in the sensory area of the brain (the area where nerve cells that cause sensations are gathered and corresponds to the nerve activity site) when a certain stimulus is given to the living body The sensory cortex is formed by light,
They are in different places depending on the external stimuli of sound and smell.

Therefore, when the location of the SQUID sensor and the location of the sensory cortex corresponding to the stimulus are largely separated from each other, there is a problem that an erroneous current source is estimated. Even if the sensory area corresponding to each stimulus is specified as an area for estimation, the sensory area cannot be accurately specified for a three-dimensional brain model. It has not been practically specified in the area of the field. In general, when a doctor determines a sensory area corresponding to each stimulus, it is based on "brain wrinkles" and the like. Therefore, a three-dimensional model accurately represents in-vivo information such as "brain wrinkles". Because they cannot do it.

The present invention has been made in view of such circumstances, and has as its object to provide a method capable of creating an accurate three-dimensional model of a nerve activity site.

[0008]

The present invention employs the following method to achieve the above object. That is, according to the present invention, a region of a nerve activity site is specified in advance for a plurality of two-dimensional images obtained by using the cerebrospinal fluid imaging method in the MR imaging method, and coordinate data of the specified region is stored. It is characterized in that a three-dimensional model of a nerve activity site is created by interpolation, and the three-dimensional model is created on an MRI three-dimensional image.

[0009]

According to the method of the present invention, a neural activity site is specified for a plurality of two-dimensional images obtained in advance by using the cerebrospinal fluid imaging method in the MR imaging method. Since two-dimensional images obtained by the cerebrospinal fluid imaging method clearly show in-vivo information such as "brain wrinkles", it is possible to accurately specify a nerve activity site. Then, a three-dimensional model of the region of the nerve activity site is created and created on an MRI three-dimensional image, so that the three-dimensional position of the nerve activity site can be accurately grasped. It can be used for conversion.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. [1] First, as shown in FIG.
-Select a plurality of slice planes along the y plane in the z direction,
A tomographic image of each slice plane is captured using an RI device (not shown). The imaging method is preferably performed using a pulse sequence for extracting cerebrospinal fluid. As a result, it is known that a slice image in which the "wrinkles" of the cerebral cortex is embossed is obtained, and the location of the sensory cortex corresponding to each stimulus can be accurately determined.

[2] Each slice image 1 as shown in FIG. 2 is displayed on a monitor display, and a nerve activity site is designated for each slice image. In other words, when estimating the biological activity current source, the sensory area corresponding to the stimulus given to the subject M is specified when obtaining the actual measurement data of the subject M. The location of the sensory cortex is already medically known. For example, on the outer surface of the right hemisphere of the cerebrum shown in FIG. The auditory cortex where nerve cells gather. In addition, a human brain diagram (Brain Atlas) showing regions of each sensory area with respect to a tomographic image of the brain is presented in a medical book or the like (see FIG. 3 (b)).

When the auditory cortex B is designated using these pieces of information, for example, from among the selected slice planes,
A slice plane corresponding to the position of the auditory cortex B in the z direction of the brain shown in FIG. As shown in the figure, since the auditory cortex B extends along the z direction of the brain, a plurality of slice planes are required. The obtained slice images 1 on the respective slice planes are displayed on the monitor display, and the region on the xy plane of the auditory cortex B is marked with reference to the human brain diagram of FIG. 3B (see FIG. 4). . As a marking method, a region of the auditory cortex B is traced with a cursor to create a line segment of a closed region.

[3] Interpolate the corresponding coordinate points of each sliced image 1 by neighborhood calculation to create a three-dimensional model of the brain. At this time, a similar interpolation process is performed on the region line segment of the designated sensory cortex to form a three-dimensional model. Then, the designated sensory area appears in the three-dimensional model of the brain as a similar three-dimensional model. When estimating a biological activity current source, the position coordinates of the three-dimensional model of the sensory cortex are designated as an area for estimation, and an arbitrary position in the three-dimensional model of the sensory cortex is assumed as a current source. Specify as a starting point for.

In the above-mentioned designation of the sensory cortex, a slice image 1 (transverse image) of the head of the subject M in the xy plane and a slice image (sagittal image) of the subject M in the xz plane May be obtained, and a three-dimensional coordinate of a three-dimensional model of the area of the sensory cortex may be obtained by specifying the area of the sensory cortex on these images.

In the above-described embodiment, an example is shown in which a three-dimensional model of a nerve activity site (sensory cortex) is used to designate an estimated area of a biological activity current source.
It can also be used for research on brain function and various diagnoses.

[0016]

As is apparent from the above description, the method for creating a three-dimensional model of a nerve activity site according to the present invention is based on the MR imaging method in which in-vivo information of a subject such as "brain wrinkles" appears accurately. Since the region of the nerve activity site is designated in the two-dimensional image obtained by the cerebrospinal fluid imaging method and then three-dimensionally modeled, an accurate three-dimensional model of the nerve activity site can be obtained. Therefore, when the internal region of the three-dimensional model is used for estimating a biological activity current source, the estimation region can be accurately specified, and the biological activity current source is estimated assuming a large number of current sources at arbitrary positions in the body. It allows for much less computational and time-saving estimation.

[Brief description of the drawings]

FIG. 1 is a diagram showing a plurality of slice planes with respect to a head of a subject.

FIG. 2 is a diagram showing an example of a slice image captured on the slice plane.

FIG. 3 is a diagram showing sensory areas of the cerebrum.

FIG. 4 is a diagram showing a sensory area designated for each slice image.

[Explanation of symbols]

 1: Slice image A: Visual cortex B: Auditory cortex M: Subject

Continuation of the front page (56) References JP-A-3-272738 (JP, A) JP-A-2-36846 (JP, A) JP-A-1-288247 (JP, A) Kiyohiro Hokin et al., “Volime Development of MR Brain 3D Image by Rendering Method ", Brain and Nerv Brain and Nerve, (1991), Vol. 43, No. 7, pp. 665-670 (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 5/055 JICST file (JOIS)

Claims (1)

(57) [Claims] An area of a nerve activity site is specified in advance for a plurality of two-dimensional images obtained by using a cerebrospinal fluid imaging method in an MR imaging method, and coordinate data of the specified area is interpolated. To create a three-dimensional model of the nerve activity site,
A method for creating a three-dimensional model of a nerve activity site, comprising creating the three-dimensional model on a three-dimensional image.