JP4709419B2 - Thin probe type ultrasonic diagnostic equipment - Google Patents

Description

とおくと、直線Ｅ２は、点Ｐ２を通るので、Ｐ２の座標は、
【数２】

で与えられる。
また、
【数３】

よって、直線Ｅ２の式は、
【数４】

となる。この関係式からＥ２上の位置データを読み出すことができる。
【００３６】
本発明は、上述した実施形態に限定されるものではなく、実施段階ではその要旨を逸脱しない範囲で種々変形して実施することが可能である。さらに、上記実施形態には種々の段階が含まれており、開示される複数の構成要件における適宜な組み合わせにより種々の発明が抽出され得る。例えば、実施形態に示される全構成要件から幾つかの構成要件が削除されてもよい。
【００３７】
【発明の効果】
本発明によると、細径プローブの挿入作業を好適にナビゲートすることができる。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る細径プローブ型超音波診断装置の構成を示すブロック図。
【図２】図１の細径プローブと体外超音波プローブとの配置を示す模式図。
【図３】図１のディスプレイモニタの表示画面例を示す図。
【図４】図１の３Ｄレンダラーの構成例を示す図。
【図５】図１の３Ｄレンダラーの他の構成例を示す図。
【図６】本実施形態において、３Ｄボリュームスキャンとポジショニングスキャンとのシーケンスを示す図。
【図７】図１のポジションディテクターによる体外プローブに対する細径プローブの相対的な位置及び方向の演算方法の説明図。
【図８】従来の表示画面例を示す図。
【符号の説明】
９…ディスプレイモニタ、
１０…ビデオインタフェース、
１１…リアルタイム３Ｄ体外超音波プローブ、
１２…送信部、
１３…受信部、
１４…ディジタルビームフォーマ、
１５…ディジタルレシーバ、
１６…エコープロセッサ、
１７…３Ｄスキャンコンバータ、
１８…３Ｄレンダラー、
１９…３Ｄレンダラー、
２０…リアルタイムコントローラ、
２１…リアルタイムコントローラ、
２２…細径超音波プローブ、
２３…ナビ用トランスジューサ、
２４…送信部、
２５…ポジションディテクター、
２６…二次元イメージング用トランスジューサ、
２７…送受信部、
２８…ディジタルレシーバ、
２９…エコープロセッサ、
３０…２Ｄスキャンコンバータ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thin probe type ultrasonic diagnostic apparatus equipped with a thin probe that can be inserted into a body cavity such as a blood vessel or a bile duct.
[0002]
[Prior art]
In recent years, a small-diameter probe is inserted directly into a body cavity such as a patient's blood vessel and bile duct, and the degree of cancer invasion to lesions, stenosis, and vessel wall is diagnosed, and surgical treatment planning and postoperative treatment effect determination, Treatments such as TAE (transcatheter arterial embolization), PTCA (percutaneous coronary dilatation), PTCR (percutaneous intracoronary thrombolysis) have been attempted. For this reason, the surgeon needs to grasp the intrusion position of the catheter or the small-diameter probe and confirm that the distal end reaches the diagnosis site or the treatment site.
[0003]
Therefore, in the past, X-ray fluoroscopy was used to image the catheter and small-diameter probe entry site in the body, and the operator monitored the tip position of the catheter and small-diameter probe while viewing the X-ray image displayed on the monitor. Was. However, in X-ray fluoroscopic monitoring, it is inevitable that not only patients but also operators will receive X-ray exposure.
[0004]
For this reason, a method for confirming the distal end position of a catheter or a small-diameter probe using an ultrasonic diagnostic apparatus instead of an X-ray fluoroscopic apparatus has been proposed. The ultrasonic diagnostic device emits an ultrasonic beam from the body surface to the inside of the body using an external probe, receives an echo signal reflected from a portion having a difference in acoustic impedance, reconstructs it, and images it. Is. However, the surfaces of catheters and small diameter probes are smooth and generally bent in vivo. For this reason, since the ultrasonic beam incident from the body surface is regularly reflected by the surface of the catheter or small probe, it often does not return to the body surface probe, and it is very difficult to detect and image the position. there were. Therefore, Japanese Patent Laid-Open No. 4-129543 proposes a method of obtaining positional information by installing a transducer at the tip of a catheter or a small-diameter probe and receiving an ultrasonic beam transmitted from an extracorporeal probe.
[0005]
Based on the obtained position information of the tip of the small-diameter probe, volume data acquired through the two-dimensional array probe outside the body is represented by a threshold value process, a maximum value projection process, and the like. It has also been proposed to display a marker of the position of the tip of the small-diameter probe on a three-dimensional rendering image (see FIG. 8). The catheter operator can perform the catheter insertion operation while confirming the tip position of the small-diameter probe with the marker in the three-dimensional rendering image.
[0006]
However, when a catheter is inserted into a blood vessel that travels in a complicated manner, it may be difficult to understand from a three-dimensional rendering image, for example, whether the blood vessel branch is advanced in the upper, lower, left or right direction. Further, when the catheter insertion path is long, it is often difficult to draw with only one three-dimensional rendering image. In these cases, if necessary, image operations such as rotating a three-dimensional rendering image and performing clipping are performed to draw a necessary part, thereby avoiding the problem. However, since the catheter inspection or operation time becomes long, there arises a problem that the burden on the patient increases.
[0007]
In addition, it is considered that the above problems can be reduced by providing a forward viewing function and a bending function at the catheter tip. However, since the catheter tip becomes large, the operability is deteriorated and the catheter application range is limited. Also, there is a problem of an increase in the cost of the catheter itself, so the feasibility is low.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide information capable of suitably navigating the insertion operation of a thin probe in a thin probe type ultrasonic diagnostic apparatus.
[0009]
[Means for Solving the Problems]
The present invention provides a thin probe type ultrasonic diagnostic apparatus that acquires and displays radial ultrasonic image data representing a tissue form around a thin probe through a thin probe inserted into the body of the subject. An extracorporeal ultrasound probe applied to the body surface of the specimen, means for acquiring three-dimensional volume data relating to the tissue morphology inside the subject via the extracorporeal ultrasound probe, and position detection for detecting the position of the small diameter probe Means for generating perspective projection image data from the three-dimensional volume data with the position of the narrow probe as a viewpoint and a line-of-sight direction in front of the narrow probe; and means for displaying the perspective projection image data It comprises.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a thin probe type ultrasonic diagnostic apparatus. The small-diameter probe is typically used in a state of being inserted into a catheter (therapeutic tubule). The catheter is generally an intravascular ultrasound catheter (IVUS; Intraductal Ultrasound), and the intravascular ultrasound probe is IDUS (Intraductal Ultrasound).
[0011]
FIG. 1 shows a configuration of a thin probe ultrasonic diagnostic apparatus according to an embodiment of the present invention. This device scans the circumference of the basic function of the thin-diameter probe type ultrasonic diagnostic apparatus, that is, a microtransducer (microtransducer) 26 for two-dimensional imaging arranged inside the tip of the catheter in a radial (circular) manner. In addition to a radial two-dimensional scanning portion for obtaining a circular tissue morphology image (hereinafter simply referred to as a radial image), a navigation portion for detecting the position of the catheter, and an external real-time three-dimensional ultrasound imaging portion Are characteristically equipped.
[0012]
(Radial 2D scanning part)
A small transducer 26 for two-dimensional imaging is arranged near the tip of the small-diameter probe 22, specifically, behind the navigation transducer 23 by a predetermined distance. The radial two-dimensional scanning portion typically obtains a circular two-dimensional image representing a tissue form by scanning the periphery of the transducer 26 with the transmission / reception unit 27 via the transducer 26 while mechanically rotating the transducer 26. It is a unit for. In addition, in the ultrasonic wave used in the radial two-dimensional scanning part,
The ultrasonic wave generated by the mechanical vibration of the transducer 26 by the drive signal propagates through the subject, is reflected by the discontinuous surface of the acoustic impedance in the middle, and returns to the transducer 26 as an echo. This echo mechanically vibrates the transducer 26. The weak electric signal generated thereby is amplified by the preamplifier of the transmission / reception unit 27, digitized, subjected to quadrature detection by the digital receiver 28, and further subjected to envelope detection by the echo processor 29. The generated ultrasonic vector data is converted into circular pixel data by the two-dimensional scan converter 30 and then sent to the video interface 10.
[0013]
(Catheter navigation part)
The catheter navigation portion is equipped to detect the tip position of the small diameter probe 22. As shown in FIGS. 2A and 2B, a navigation transducer 23 is disposed at the tip of the small-diameter probe 22. The transmitter 24 applies a drive signal to the navigation transducer 23 in synchronization with the navigation pulse generation signal generated by the real-time controller 21. As a result, an omnidirectional ultrasonic pulse is generated from the navigation transducer 23.
[0014]
The omnidirectional ultrasonic pulse propagates inside the subject and is received by the extracorporeal ultrasonic probe 11. The position detector 25 estimates the position of the navigation transducer 23, that is, the tip position of the small-diameter probe 22 based on the received signal. Of course, this position is the tip position of the small-diameter probe 22 relative to the extracorporeal ultrasonic probe 11, and is a coordinate system unique to the extracorporeal ultrasonic probe 11, for example, an XYZ coordinate system with the center of the extracorporeal ultrasonic probe 11 as the origin. It is expressed by
[0015]
Typical position estimation methods include a GPS method and a maximum energy pulse detection method. In the present embodiment, either of them may be adopted, both may be adopted, and they may be selectively used, or both formulas are used together and the final result is obtained from these two results (estimated positions). A specific position may be determined.
[0016]
a) Navigation ultrasonic waves received in three discrete groups of three discrete points within the array plane of the GPS system extracorporeal ultrasonic probe 11, that is, a discrete three transducers or a predetermined number of adjacent transducers as one group. Based on the phase difference or time difference between the three received signals of the pulse, the position of the navigation transducer 23 viewed from the center point of the extracorporeal ultrasonic probe 11 is estimated by triangulation. In principle, the position can be estimated by one reception. However, when the S / N is poor, the transmission / reception and the position estimation are repeated several times, and the center of gravity positions of the plurality of estimated positions are used as the final positions. It may be determined.
[0017]
b) Energy maximum pulse detection method The navigation ultrasonic pulse received by the extracorporeal ultrasonic probe 11 is beam-formed in multiple directions by the digital beam former 14, and the maximum energy (maximum wave height) therein is obtained by the position detector 25. The position of the point on the selected beam is extracted. That is, the maximum energy point obtained by scanning the entire volume is the position of the navigation ultrasonic pulse generation source, that is, the navigation transducer 23. This method achieves a higher S / N than the previous GPS method, but requires a long time for estimation because the beamforming process is repeatedly executed in multiple directions.
[0018]
(External real-time 3D ultrasound imaging part)
The real-time three-dimensional extracorporeal ultrasonic probe 11 is a probe that is in contact with the body surface of the subject, as shown in FIG. 2A, unlike the small-diameter probe 22 inserted into the subject. In order to scan a three-dimensional (3D) region inside the subject with ultrasonic waves at high speed, a plurality of transducers arranged in a two-dimensional manner are provided. A transmitter 12 is connected to the extracorporeal ultrasound probe 11 during transmission, and a receiver 13 is connected during reception. The transmission unit 12 is provided with a plurality of pulsers, a transmission delay circuit, and a pulse generator respectively connected to the plurality of transducers. The pulser is generated from the pulse generator at a fixed period, and a pulse signal delayed by the transmission delay circuit for beaming and directing the ultrasonic wave is used as a trigger to drive the transducer (high-frequency voltage signal). Apply.
[0019]
The ultrasonic wave generated by the mechanical vibration of the transducer to which the drive signal is applied propagates inside the subject, is reflected by the discontinuous surface of the acoustic impedance in the middle, and returns to the probe 11 as an echo. This echo mechanically vibrates the transducer of the probe 11. The weak electric signal generated thereby is amplified by the preamplifier of the receiving unit 13, digitized, and subjected to phasing addition processing by the digital beam former 14. As a result, a reception signal having directivity is generated. The transmission unit 12 and the reception unit 13 change the directivity of transmission and reception for each transmission and reception under the control of the real-time controller 21 and scan the three-dimensional region inside the subject with an ultrasonic beam. In actual examination, the position of the extracorporeal probe 11 is set so that the vicinity of the tip of the small-diameter probe 22 is included in this three-dimensional scanning range.
[0020]
The reception signal generated by the reception unit 13 is subjected to quadrature detection by the digital receiver 15 and further supplied to the echo processor 16. The echo processor 16 performs envelope detection on the received signal and generates data representing the tissue morphology. This data is converted into three-dimensional volume data as a voxel aggregate by a three-dimensional scan converter 17 and supplied to three-dimensional renderers 18 and 19 that generate two types of three-dimensional images from the three-dimensional volume data. Rendering, as is well known, refers to rendering volume data in a three-dimensional representation into a two-dimensional image so that it can be drawn on the display monitor 9, and as a process, the coordinate position of the volume data is first converted into a viewpoint coordinate system. Then, an image is generated through the hidden surface processing and the shading that shades the object surface. Here, two systems 18, 19 are provided as three-dimensional renderers. These two systems of three-dimensional renderers 18 and 19 generate three-dimensional images with different expressions.
[0021]
The three-dimensional renderer 18 arranges the viewpoint at an arbitrary position outside the three-dimensional region (external), for example, the center position of the extracorporeal probe 11 from the three-dimensional volume data acquired via the extracorporeal two-dimensional array probe 11. Then, a three-dimensional rendering image representing the external structure of the blood vessel similar to the conventional one shown in the left screen of FIG. 3 is generated in the line-of-sight direction toward the detected catheter tip position. The three-dimensional renderer 19 uses the same line-of-sight direction in the axial direction (traveling direction) from the tip of the catheter, as shown in the right screen of FIG. 3, from the three-dimensional volume data acquired via the two-dimensional array probe 11 outside the body. To produce an endoscopic perspective image looking forward. The three-dimensional rendering image and the endoscopic-like perspective projection image are combined into one screen by the video interface 10 and are simultaneously displayed on the display monitor 9. The operator grasps the blood vessel travel and the approximate position of the catheter by the conventional three-dimensional rendering image, and at the same time, navigates the catheter by the endoscope-like perspective projection image, that is, the catheter is inserted into the blood vessel branch to be advanced. Can be confirmed. When the traveling direction of the probe 22 is reversed as the probe 22 is retreated, the line-of-sight direction is reversed with respect to the traveling direction.
[0022]
The three-dimensional renderer 19 enables rendering processing by either or both of volume rendering and surface rendering. As an actual configuration example, as shown in a typical configuration in FIG. 4, the input stage is composed of two systems of volume memories 32 and 33 around the memory controller 31, and the direct memory access controller 34 is connected to this input stage. The processing stage is connected at high speed via the PCI bus 34, and the processing stage has a general configuration including a system controller 38, a CPU 36, a main memory 39, a graphic controller 40, and a frame memory 41. Can be provided. In order to increase the speed by parallel processing of volume rendering and surface rendering, the CPUs 36 and 37 can be parallelized as shown in FIG. In this case, the system controller 38 has two CPU interfaces and the OS uses a multithread function. Each of the two types of rendering processing is processed in parallel as different threads.
[0023]
As the surface rendering, the three-dimensional renderer 19 generates boundary surface geometric information by extracting the boundary of the blood vessel inner wall or the body cavity inner wall from the three-dimensional volume data acquired via the two-dimensional array probe 11 outside the body. For the boundary extraction, a generally known method such as SNAKE method or ACT method can be used. In order to improve the efficiency of the blood vessel inner wall search, the blood vessel inner wall search is performed with the position of the transducer 23 (catheter tip position) as the initial position. The boundary surface geometric information is expressed as a set of triangles, and is generated as polygon information widely used in computer graphics. In particular, by holding data in a format compatible with OpenGL, which is one of 3D graphics APIs (Application Program Interface), it is possible to realize drawing by a low-cost personal computer. Specifically, the drawing is performed by a surface rendering method using OpenGL. In order to perform perspective projection with a depth, the size and projection position of the polygon are corrected according to the distance between the viewpoint position and the polygon.
[0024]
The viewpoint is set at the tip position of the detected catheter. The line-of-sight direction is set along the traveling direction by calculating the traveling direction of the catheter from the two catheter tip positions detected by two consecutive position detecting operations this time and the previous time. When the amount of movement of the catheter between the two position detection operations is 0, that is, when the catheter is stationary during that time, the viewing direction is set to be the same as the previous viewing direction. If there is some movement due to heartbeat, the direction may not be changed if it is below a certain threshold.
[0025]
Immediately after the start of navigation, the catheter traveling direction is not determined, so the direction is determined by one of the following methods.
Method 1) An initial traveling direction is determined as a default value.
Method 2) A user sets an initial direction of travel using input means such as a mouse or a joystick.
Method 3) A search is performed in six directions from the viewpoint position, and the distance to the collision with the polygon is the longest.
[0026]
This method 3 is based on the assumption that the catheter is often placed at the end of the volume when navigation is started. In addition, as a texture mapping, a function obtained from volume data collected via a two-dimensional array probe 11 outside the body or a three-dimensional volume obtained by mechanical scanning of a transducer attached to the distal end of the catheter Define the shape information as a texture corresponding to the generated polygon and texture-map it to the perspective projection image. This can be realized as a function defined by OpenGL. The function / form information includes the following.
[0027]
As information collected by the extracorporeal probe 11, the blood flow velocity or the blood flow direction measured by the color Doppler method is mapped. The information collected by the catheter probe 22 includes blood vessel / body cavity wall thickness. Thickness is calculated by performing threshold processing on the reflection intensity from the blood vessel wall, and is associated with hue, saturation, and luminance (including gray level). The simplest method is to measure the thickness radially from the surface of the vibrator. However, if the thickness is eccentric, an error occurs. By determining the center by extracting the blood vessel wall and calculating the center of gravity, it is possible to estimate a more accurate wall thickness.
[0028]
Furthermore, there is a wall unevenness degree. Volume data collected through the two-dimensional array probe 11 outside the body has a larger positional error than volume data collected by the catheter probe 22. Therefore, subtle irregularities on the blood vessel surface are not reflected in the extracted blood vessel geometric information. Extract the vessel surface collected with the catheter and fit the ellipse. The difference from the ellipse is calculated at each part and associated with the gray level or hue, saturation, and luminance.
[0029]
When the information collected by the catheter probe is texture-mapped, the texture of the portion where the catheter has not reached is displayed in a different expression, so that when the catheter is pulled back, arrival / non-arrival can be easily recognized.
[0030]
As described above, in the 3D renderer 19, instead of generating polygon information by boundary extraction, it is also possible to generate a perspective projection image using a volume rendering method. Although the process is heavier than surface rendering, a relatively good three-dimensional image can be obtained even when boundary extraction is difficult. The method for determining the line-of-sight direction is the same as in the case of surface rendering.
[0031]
FIG. 6A shows a three-dimensional volume scanning with the extracorporeal ultrasonic probe 11 in the present embodiment and a non-directional supersonic wave from the transducer 23 to detect the position of the transducer 23 of the small-diameter probe 22 (the position of the tip of the catheter). A sequence of positioning and scanning in which a sound wave is transmitted and received by the extracorporeal ultrasonic probe 11 is shown. As described above, since these operations use ultrasonic waves in the same frequency band, both operations need to be performed in a time-sharing manner. Here, every time the volume scanning is repeated a predetermined number of times, for example, 8 times, the positioning / scanning is performed once.
[0032]
As shown in FIG. 6B, positioning scanning is performed a plurality of times for one volume scanning. This timing chart shows an example of control that is performed three times at the start, end, and intermediate time of volume scanning. The time required for volume scanning is very long in the scanning method using the color Doppler method, and thus the catheter navigation is facilitated by frequently updating the catheter position marker and the perspective projection image. When the collection time of volume scanning is short, it is possible to minimize the influence of the position shift due to the heartbeat by performing the average processing of the detection positions. Positioning scanning at the end of volume scanning can be combined with that at the start of the next volume scanning.
[0033]
FIG. 7 is an explanatory diagram regarding the position detection of the position of the transducer 23 of the small diameter probe 22 (the tip position of the catheter) by the position detector 25. The center position of the external real-time three-dimensional ultrasonic probe 11 is taken as the origin (0, 0) of the X and Y axes. N1 is the position of the navigation transducer 23 attached to the tip of the catheter at time t1 (x1, y1), and P1 is the position of the radial scan transducer 26 attached to the central portion of the catheter at that time. Let L be a fixed distance between the navigation transducer 23 and the radial scan transducer 26. Further, the position of the navigation transducer 23 at time t2 after the elapse of the positioning / scanning period from time t1 is N2 (x2, y2), and the position of the radial scan transducer 26 is P2. Thus, the catheter is traveling from N1 to N2 (P1 to P2). A line connecting these N1 and N2 (P1 and P2) is D, and a line E1 perpendicular to D corresponds to a plane including a cross section (radial scan plane) of an image obtained by the radial scan transducer 26 of the catheter. Similarly, the cross section after a certain time is E2.
[0034]
Therefore, it is necessary to extract information on the cross sections E1 and E2 from the volume data collected by the external real-time three-dimensional probe 11, and the position and direction of the cross section are calculated by the radial scan plane selector 31 of FIG. . The calculation result or voxel data on the cross section represented by the calculation result is sent to the video interface 10.
[0035]
An example of the calculation method is shown below.
Inclination of the straight line D: (y ₂ −y ₁ ) / (x ₂ −x ₁ )
Since the slopes of the straight lines E1 and E2 are perpendicular to D: (x ₂ −x ₁ ) / (y ₂ −y ₁ )
The equation for the straight line E2 is

Since the straight line E2 passes through the point P2, the coordinates of P2 are
[Expression 2]

Given in.
Also,
[Equation 3]

Therefore, the equation of the straight line E2 is
[Expression 4]

It becomes. The position data on E2 can be read from this relational expression.
[0036]
The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. Furthermore, the above embodiment includes various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, some constituent requirements may be deleted from all the constituent requirements shown in the embodiment.
[0037]
【The invention's effect】
According to the present invention, it is possible to suitably navigate the insertion operation of the small diameter probe.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a thin probe ultrasonic diagnostic apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing the arrangement of the small-diameter probe and the extracorporeal ultrasonic probe of FIG.
3 is a diagram showing an example of a display screen of the display monitor in FIG. 1. FIG.
4 is a diagram showing a configuration example of the 3D renderer in FIG. 1. FIG.
FIG. 5 is a diagram showing another configuration example of the 3D renderer in FIG. 1;
FIG. 6 is a diagram showing a sequence of 3D volume scanning and positioning scanning in the present embodiment.
7 is an explanatory diagram of a method for calculating a relative position and direction of a small-diameter probe with respect to an extracorporeal probe by the position detector of FIG. 1;
FIG. 8 is a diagram showing an example of a conventional display screen.
[Explanation of symbols]
9 ... Display monitor,
10 ... Video interface,
11 ... Real-time 3D extracorporeal ultrasound probe,
12 ... Transmitter,
13 ... receiving part,
14 ... Digital beamformer,
15 ... Digital receiver,
16 ... Echo processor,
17 ... 3D scan converter,
18 ... 3D renderer,
19 ... 3D renderer,
20 ... Real-time controller,
21 ... Real-time controller,
22 ... a small-diameter ultrasonic probe,
23 ... Transducer for navigation,
24 ... Transmitter,
25 ... Position detector,
26. Transducer for two-dimensional imaging,
27: Transmitter / receiver,
28: Digital receiver,
29 ... Echo processor,
30 ... 2D scan converter.

Claims (15)

In a thin probe type ultrasonic diagnostic apparatus that acquires and displays radial ultrasonic image data representing a tissue form around the thin probe through a thin probe inserted into the body of a subject,
An extracorporeal ultrasound probe applied to the body surface of the subject;
Means for acquiring three-dimensional volume data relating to a tissue form inside the subject via the extracorporeal ultrasonic probe;
Position detecting means for detecting the position of the small diameter probe;
Means for generating perspective projection image data from the three-dimensional volume data with the position of the narrow probe as a viewpoint and the line-of-sight direction in front of the narrow probe;
An ultrasonic diagnostic apparatus comprising: means for displaying the perspective projection image data.   The ultrasonic diagnostic apparatus according to claim 1, wherein the extracorporeal ultrasonic probe includes a plurality of transducers arranged two-dimensionally.   The means for detecting the position of the small-diameter probe includes: a vibrator that generates an omnidirectional ultrasonic wave mounted on the small-diameter probe; and an omnidirectional ultrasonic wave received via the extracorporeal ultrasonic probe. The ultrasonic diagnostic apparatus according to claim 1, further comprising a position calculating unit that calculates a relative position of the small-diameter probe based on a received signal.   The position calculating means calculates a relative position of the small-diameter probe based on a phase difference or a time difference of reception signals received at at least three discrete points of the extracorporeal ultrasonic probe. 3. The ultrasonic diagnostic apparatus according to 3.   The said position calculating means specifies the point which shows the maximum intensity | strength of the received signal from which the directivity differs through the said extracorporeal ultrasonic probe as a relative position of the said small diameter probe. Ultrasound diagnostic equipment.   The means for generating the perspective projection image data calculates a traveling direction of the small-diameter probe based on the detected at least two positions, and identifies the line-of-sight direction based on the traveling direction. The ultrasonic diagnostic apparatus as described.   The means for generating perspective projection image data reverses the line-of-sight direction with respect to the reversed traveling direction when the traveling direction of the small-diameter probe is reversed as the small-diameter probe is retreated. The ultrasonic diagnostic apparatus according to claim 6.   The ultrasonic diagnostic apparatus according to claim 1, wherein the perspective projection image data is generated by at least one of a volume rendering method and a surface rendering method.   The ultrasonic diagnostic apparatus according to claim 1, further comprising means for synthesizing a blood flow velocity image with the perspective projection image.   2. The ultrasonic diagnostic apparatus according to claim 1, further comprising means for generating three-dimensional rendering image data representing an external structure of a blood vessel from the three-dimensional volume data.   The ultrasonic diagnostic apparatus according to claim 10, wherein a marker representing a position of the small-diameter probe is synthesized with the three-dimensional rendering image data. The ultrasonic diagnostic apparatus according to claim 11, wherein the marker is set at a position specified by an average process of a plurality of positions of the small diameter probe detected a plurality of times.   The ultrasonic diagnostic apparatus according to claim 10, wherein the three-dimensional rendering image data is displayed simultaneously with the perspective projection image data.   The ultrasonic scanning for acquiring the three-dimensional volume data and the transmission / reception of the omnidirectional ultrasonic waves for detecting the position of the small diameter probe are repeated in a time division manner. Ultrasonic diagnostic equipment. 14. the transmission and reception of the non-directional ultrasonic waves was characterized by a plurality of times to detect the position of the small diameter probe for a single ultrasound scan for the acquisition of the three-dimensional volume data The ultrasonic diagnostic apparatus as described.

Images