CN102613990B - Display method of blood flow rate of three-dimensional ultrasonic spectrum Doppler and space distribution of blood flow rate - Google Patents

Abstract

The invention discloses a display method of the blood flow rate of three-dimensional ultrasonic spectrum Doppler and the space distribution of the blood flow rate, which designs a three-dimensional visualization method. The method comprises the steps of obtaining flow velocity distribution in different positions along the cross section of a blood vessel through a plurality of doors, and finally obtaining additional distribution and time information. The method adopting the ultrasonic spectrum Doppler technology and three-dimensional visualization display to evaluate the space distribution of blood flow rate in the blood vessel has great clinical meaning on the diagnosis of angiocardiopathy, and is applicable to the technical field of medicine.

Description

The blood flow rate of three-D ultrasonic frequency spectrum Doppler and spatial distribution display packing thereof

Technical field

The invention belongs to medicine technology field, relate to a kind of blood flow rate and spatial distribution display packing thereof of three-D ultrasonic frequency spectrum Doppler.

In medical ultrasonic cardiovascular disease, detect in application, by direction, speed and the turbulent fluctuation information of blood flow are provided, can determine flow velocity and the VELOCITY DISTRIBUTION thereof of blood flow, to reach the object of auxiliary diagnosis.Frequency spectrum Doppler is by focusing on the scattering impact signal that transmitting repeats and calculate the VELOCITY DISTRIBUTION in Range Gate to being called as on the same space position of Range Gate (scope door).Next, velocity profile information is shown with spectrogram form, and spectrogram is a chart changing along with the time, express time in one direction, expression speed in another direction.

Traditional frequency spectrum Doppler is thereby that the base complex signal belonging in same door is averaged to the frequency spectrum calculating in time series.Time series is also referred to as time dimension.

As follows with reference to Fig. 1 frequency spectrum Doppler principle:

$f_d=\left(\frac{2v{f}_s}{c}\right)\cos \mathrm{\&theta;},(v<<c)$

Wherein v is flow velocity, and c is sound velocity of wave propagation, and fd represents to be detected to obtain Doppler frequency shift, and fs is source frequency, and θ represents the angle of blood flow and ultrasonic beam.Actual frequency spectrum Doppler adopts following formula:

$x(d,n)=\exp \left(j2\mathrm{\&pi;}\frac{f_c}{f_s}d\right)\underset{\mathrm{\&upsi;}}{\mathrm{\&Sigma;}}{\mathrm{\&alpha;}}_{\mathrm{\&upsi;}}\exp \left(j2\mathrm{\&pi;}\frac{2f_c\mathrm{\&upsi;}}{c{f}_{\mathrm{prf}}}n\right)$

Wherein, x0 is actual reception signal, and d, n are relevant with watch window, f _ssample frequency when fast, f _prfsample frequency when slow, α _vfor velocity flow profile.

But traditional frequency spectrum Doppler is defectiveness also.When data in scope door are summed, the spatial information of blood flow can be lost.Therefore, the turbulent fluctuation information of blood flow is usually propagated to infer by the spectrum width in Gate (door) or flow velocity.Yet because the distance apart from blood vessel wall is different, the velocity profile of the laminar flow blood flow in blood vessel is similar to a parabolic.Therefore, the spatial information of flow velocity and VELOCITY DISTRIBUTION have equal importance.

According to this thought, we have designed a kind of three-dimensional visualization method.The spatial distribution of utilizing the ultrasonic spectral Doppler technology of many sampling gates and three-dimensional visualization thereof to show to assess blood vessel Inner blood flow rate has important clinical significance to the diagnosis of what cardiovascular disease.

Summary of the invention

The object of the invention is to overcome above-mentioned technological deficiency, a kind of blood flow rate and spatial distribution display packing thereof of three-D ultrasonic frequency spectrum Doppler is provided.The method is used a plurality of doors to obtain velocity flow profile along the cross section of blood vessel in the position different, and finally can obtain extra distribution and temporal information.

Its technical scheme is:

The blood flow rate of three-D ultrasonic frequency spectrum Doppler and a spatial distribution display packing thereof, comprise the steps:

1) scope of the door that user selects has enough large, large to covering whole blood vessel;

2) scope door is divided into M cervical orifice of uterus;

3) frequency spectrum that obtains summed time series in each cervical orifice of uterus can calculate with different spectral methods;

4) with three dimensions, show M sub-frequency spectrum: the M of frequency spectrum section stacked, then in three dimensions, rebuild, each voxel represents size and the frequency spectrum speed of the spectral density in the cervical orifice of uterus corresponding with it, the energy spectral density that the intensity representative frequency spectrum corresponding with it of voxel cut into slices.

5) with said three-dimensional body rendering intent, carry out imaging, and careful selection opacity value, enable the energy of comprehensive demonstration frequency spectrum.Further preferably, step 5), three-dimensional rendering method comprises the following steps:

A) volume data is stored in the three-D grain of video memory;

B) on this basis, generate the series of parallel tangent plane vertical with direction of observation, and each tangent plane is cooked to Tri linear interpolation;

C) use Alpha to merge and realize light emission absorption function, following formula, and obtain final 3-D view;

C wherein _iand A _iaccording to the color and the opacity value that obtain in voxel and the transfer function combined effect at i place, sampling location, opacity A _iapproximate light absorption process, the color value C processing through weighting _ibe similar at sampling location i and i+1 place along light emission and the absorption process of light slice direction.

Compared with prior art, beneficial effect of the present invention is:

The method of the invention allows the blood flow rate of observing in time domain that doctor both can be real-time to change, and wherein comprises several contraction/relaxation cycles, also can spatially judge laminar flow or turbulent flow.And the present invention also provides the function of the two-dimensional cross section that any two dimensions are combined to form.

Accompanying drawing explanation

Fig. 1 is background technology schematic diagram of the present invention;

Fig. 2 is the inventive method step 2) schematic diagram;

Fig. 3 is the inventive method step 4) schematic diagram;

Fig. 4 is the inventive method step 5) in b) schematic diagram of step;

Fig. 5 is the three-dimensional frequency spectrum Doppler display effect figure of analog data;

Fig. 6 utilizes method of the present invention for the carotid treatment effect figure of a Healthy People.

The specific embodiment

Below in conjunction with accompanying drawing and specific embodiment, the present invention is described in more detail.

The blood flow rate of three-D ultrasonic frequency spectrum Doppler and a spatial distribution display packing thereof, comprise the steps:

1) scope of the door that user can select has enough large, large to covering whole blood vessel.

2) above-mentioned scope door is divided into M cervical orifice of uterus, as shown in Figure 2.

3) frequency spectrum that obtains summed time series in each cervical orifice of uterus can calculate with different spectral methods, for example Short Time Fourier Transform.

4) with three dimensions, show M sub-frequency spectrum: the M of frequency spectrum section stacked, then in three dimensions, rebuild, as shown in Figure 3.Each voxel represents size and the frequency spectrum (speed) of the spectral density in the cervical orifice of uterus corresponding with it.The energy spectral density that the intensity representative frequency spectrum corresponding with it of voxel cut into slices.

5) with said three-dimensional body rendering intent, carry out imaging, and careful selection opacity value, enable the energy of comprehensive demonstration frequency spectrum.Three-dimensional rendering method is as follows:

A) volume data is stored in the three-D grain of video memory.

B) on this basis, generate the series of parallel tangent plane vertical with direction of observation, and each tangent plane is cooked to Tri linear interpolation, as shown in Figure 4:

C) use Alpha to merge and realize light emission absorption function, following formula, and obtain final 3-D view.

C wherein _iand A _iaccording to the color and the opacity value that obtain in voxel and the transfer function combined effect at i place, sampling location.Opacity A _iapproximate light absorption process, the color value C processing through weighting _ibe similar at sampling location i and i+1 place along light emission and the absorption process of light slice direction.

Derivative result:

1., if will carry out interpolation (Tri linear interpolation) operation when playing up, the number of door must reduce again.

2. show any one the two-dimentional tangent plane in three-dimensional data.This just can guarantee that spatial distribution situation (Spatial Dimension and speed dimension) shows on an independent image, also can guarantee to show the combined information of other dimensions on an independent image.

3. in system, realize real-time three-dimensional data and upgrade, so just can realize four-dimensional dynamic visual.

4. measure bag: for example follow the trail of two-dimentional tangent plane, face extracts, and calculates curvature or gradient.

5. various modes.For example, can combine with B pattern and C pattern.

6. can combine with the method for current existence.For example, image is compound, code-excited, the spectrum estimation of frame losing etc.In order to detect along the laminar flow of the parabolic shape on blood vessel wall border, conventionally very high to the requirement of resolution.Therefore code-excited technology is even more important in this case.Traditional Doppler pulse ripple adopts 10 to 15 Cycle, thereby this can be potential, the fuzzy information of falling on Spatial Dimension causes unconspicuous parabolic shape.

Simulation process is as follows:

1. gather conventional frequency spectrum in actual body

2. service routine is the frequency spectrum copy of 64 parabolic shapes by actual spectrum division.The reason of doing is like this: the real data from many Gate can't directly collect at that time system.

3. with said three-dimensional body method for drafting, play up this 64 frame frequency spectrum copy, and allow manual setting opacity to control transfer function.

Rebuilt and the three dimensional display test result played up is as shown in Figure 5:

The method of the invention has been carried out human trial, has shown the carotid treatment effect for a Healthy People in Fig. 6.In Fig. 6 a, the present invention is equidistant and parallel a plurality of cervicals orifice of uterus by shown door cutting, and this test is 16, and on each cervical orifice of uterus, does traditional frequency spectrum demonstration.Next, the spatial distribution form of certain time point is revealed in Fig. 6 b, and it has shown a profile that is similar to parabolic shape.In Fig. 6 c, the frequency spectrum data that comes from certain in three-dimensional data is shown.In Fig. 6 d, three-dimensional data is carried out to volume drawing, and the spectrum distribution display mode in the time of depending on, space is provided.

Embodiments of the invention are not limited to this, any type of simple change, and equivalence is replaced and is all fallen within the scope of protection of the present invention.With three dimensional form, show that the spatio-temporal distribution information about blood flow is a kind of brand-new technology, and can also from three-dimensional data, choose arbitrarily a two dimension slicing and show.

Claims (1)

1. the blood flow rate of three-D ultrasonic frequency spectrum Doppler and a spatial distribution display packing thereof, is characterized in that, comprises the steps:

1) scope of the door that user selects has enough large, large to covering whole blood vessel;

2) scope door is divided into M cervical orifice of uterus;

3) frequency spectrum that obtains summed time series in each cervical orifice of uterus calculates with different spectral methods;

4) with three dimensions, show M sub-frequency spectrum: the M of frequency spectrum section stacked, then in three dimensions, rebuild, each voxel represents size and the frequency spectrum speed of the spectral density in the cervical orifice of uterus corresponding with it, the energy spectral density that the intensity representative frequency spectrum corresponding with it of voxel cut into slices;

5) with said three-dimensional body rendering intent, carry out imaging, and select opacity value, enable the energy of comprehensive demonstration frequency spectrum;

Described three-dimensional rendering method comprises the following steps:

A) volume data is stored in the three-D grain of video memory;

B) on this basis, generate the series of parallel tangent plane vertical with direction of observation, and each tangent plane is cooked to Tri linear interpolation;

C) use Alpha to merge and realize light emission absorption function, following formula, and obtain final 3-D view;

$C=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{C}_i\underset{j=1}{\overset{i-1}{\mathrm{\&Pi;}}}(1-A_j)$

$A=1-\underset{j=1}{\overset{n}{\mathrm{\&Pi;}}}(1-A_j)$

C wherein _iand A _iaccording to the color and the opacity value that obtain in voxel and the transfer function combined effect at i place, sampling location, opacity A _iapproximate light absorption process, the color value C processing through weighting _ibe similar at sampling location i and i+1 place along light emission and the absorption process of light slice direction.