RU2629064C1 - Device for stereotaxic targeting of biopsy needle under mri control - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: device for stereotaxic tarfeting of a biopsy needle under MRI control contains a support, a carriage, a cylindrical rod and a biopsy needle. It differs by the support is made in the form of a frame compatible with the upper frame, which has a millimeter scale and a groove with inclined walls for connection to the carriage and assurance of its transverse movement. To fix the carriage position, a bar with an angular scale and carriage fixing screws are inserted, a holder of a cylindrical rod is placed between the carriage and the bar. The carriage and holder have fixing screws for cylindrical rod position, and the bar with the angular scale has a screw-lock for its angle of rotation, in addition, the bar with the angular scale, the holder and the carriage have holes for placement on a cylindrical rod having a millimeter scale, at the beginning of which a tip having a flask for contrast, a channel for a needle and a screw fixing its position, is installed.

EFFECT: device allows accurate navigation and sampling of diagnostic material in any area of the body, provides reliable fixation with a radio frequency coil, which allows to accurately monitor the position of the contrast flask and needle during biopsy on MR tomograms.

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Description

The invention relates to medical equipment, in particular to devices for performing targeted biopsies of internal organs, soft tissues, bones and various tumors under the control of magnetic resonance imaging in order to diagnose various diseases.

In a number of cases of diagnostic studies, ambiguously interpreted results of radiation and clinical examination methods arise, which creates the need for an accurate diagnosis by means of a targeted histological examination of material obtained using minimally invasive diagnostic intervention procedures (Barentsz JO MR intervention in the pelvis: an overview and first experiences in MR-guided biopsy in nodal metastases in urinary bladder cancer // Abdom Imaging, 1997, 22: 524-530). The absence of radiation exposure, high contrast of soft tissues and the ability to obtain images in any plane make magnetic resonance imaging (MRI) an ideal way to control when performing interventional intervention (Lamb GM, Gedroyc WM Interventional magnetic resonance imaging // Br J Radiol, 1997, 70: S81-S88). In addition, there are pathological conditions that are detected only on MRI and require the use of this method only as a control for the invasive diagnostic procedure (Solomon SB, Bohlman ME, Choti MA (2002) Percutaneous gadolinium injection under MR guidance to mark target for CT- guided radiofrequency ablation. J Vasc Interv Radiol 13: 419-421). However, despite the high efficiency of this area, the use of magnetic resonance imaging in interventional radiology is limited by its low prevalence and technical complexity of the method (Lamb G.M., Gedroyc W.M. Interventional magnetic resonance imaging // Br J Radiol, 1997, 70: S81-S88). One limitation is the precise navigation of the biopsy instrument.

Known stereotactic system according to patent RU No. 2125835. The system is used for tomographic studies of invasive and non-invasive stereotactic operations on the human brain. The stereotactic system is assembled in the form of three assemblies. The first assembly consists of a patient head retainer and a stereotactic adapter. It is intended for carrying out a diagnostic procedure and localization of an intracerebral target. The second assembly consists of a stereotactic phantom and an arc with a guiding device. It serves to guide the stereotactic instrument onto the image of the intracerebral target. The third assembly consists of a head and arc retainer with a stereotactic instrument and is intended for stereotactic surgery on the patient’s brain. Assemblies allow you to quickly, simply and clearly, excluding complex mathematical calculations, perform stereotactic guidance directly on the image of the intracerebral target and conduct a stereotactic operation. Also known device for stereotactic guidance of a surgical instrument according to patent RU No. 2138223. The device is used in neurosurgery for operations on the head and neck. The device comprises a main ring, a phantom ring with a coordinate device, as well as a portable arc with a guide module for a surgical instrument. The rings are made with a removable segment. The portable duta is fixed on the removable segment with an axis and can be shifted and rotated relative to it. The axis is mounted on the segment with the possibility of displacement along it. The removable segment can be mounted alternately on both rings. The device improves the accuracy of surgical instrument guidance, expands access to the surgical field during stereotactic operations and allows stereotactic guidance for all major types of neurosurgical operations on the head and neck.

The disadvantages of the devices according to patents RU No. 2125835 and No. 2138223 are their narrow use when performing minimally invasive procedures on the brain and neck and the inability to use in other areas, such as the chest, abdominal cavity, pelvis, soft tissues and bone structures. Moreover, the devices are not intended for use in a strong magnetic field, do not have fastenings to the table of a magnetic resonance imager or to special radio-frequency coils, which limits their use in magnetic resonance imaging.

The prototype of the proposed technical solution is a device for lateral percutaneous stereotactic puncture of the intervertebral discs according to patent RU No. 2093101. The device is used for puncture of intervertebral discs during discographic examination, as well as for the introduction of anesthetics and drugs dissolving disc hernias into the disc. It contains supporting and bearing parts, a rack with a scale and a goniometer mechanism with an angular scale, an arrow and a guide for a puncture needle. The goniometer mechanism is mounted on the supporting part with the possibility of fixed displacement and contains a carriage rigidly connected to the angular scale. The rod mounted in the carriage with the possibility of rotation is made with an axial blind hole at one of the ends and two grooves in the axial plane. The grooves are made to the entire depth of the hole to accommodate a puncture needle and fix it with a cylindrical sleeve and nut. At the same time, an arrow is fixed at the other end of the rod. The device is equipped with a frame movably mounted on a rack with an arrow-pointer, the end of which corresponds to the plane of the puncture needle. The disadvantages of this device is the narrow and specific clinical use in vertebrology, the inability to fix to the table of a magnetic resonance imager, or to a radio frequency coil. This device is used in conditions of x-ray control and, therefore, the materials from which it is made exclude its use in a strong magnetic field.

The technical result of the invention is to create an MP compatible stereotactic device that allows biopsy in a strong magnetic field, with reliable fixation to the radiofrequency coil in any part of the body, which allows you to deliver the working end of the stereotaxic instrument to the desired location with a high degree of accuracy, which in turn reduces the time of manipulation, increases the accuracy and reliability of stereotactic intervention.

Previous experience gained by the authors in performing about 50 minimally invasive interventions under the control of magnetic resonance imaging, which used stepwise blind needle advancement using the “free hand” method, together with the patient’s breathing excursion, created problems in reliable fixation and accurate guidance of the biopsy instrument, which led to an increase in the number of biopsy stages and the duration of the intervention itself.

All this prompted the formulation of requirements for the creation of a stereotactic instrument capable of conducting accurate navigation and fixation of a biopsy instrument in a strong magnetic field in order to increase accuracy and reduce the time of diagnostic intervention.

The essence of the invention includes a support, a carriage, a cylindrical rod and a needle. In it, the support is made in the form of a lower frame, which is combined with the upper frame. The upper frame has a millimeter scale and a groove with inclined walls for connecting to the carriage and ensuring its transverse movement. A strap with an angular scale for fixing the carriage and a holder for the cylindrical rod are also introduced into the device. In this case, the carriage, the bar with an angular scale and the holder have holes for placement of a cylindrical rod in them. In addition, the carriage and holder have screws for fixing the rotation angle and the position of the cylindrical rod. The cylindrical rod has a millimeter scale, at the origin of which a limit switch is installed, which has a bulb for contrast, a channel for the needle and a screw for fixing its position.

List of figures

FIG. 1 General view of the device: 1 - support, 2 - upper frame 3 - carriage, 4 - cylindrical rod, 5 - needle.

FIG. 2 Device details: 1 - support, 2 - upper frame, 3 - carriage, 4 - cylindrical rod, 5 - needle, 6 - millimeter scale of the frame, 7 - groove, 8 - bracket of the carriage with an angular scale, 9 - screws for fixing the position of the carriage 10 - holder of a cylindrical rod, 11 - screws for fixing the position of the cylindrical rod, 12 - screw for fixing the angle of rotation of the cylindrical rod, 13 - millimeter scale of the cylindrical rod, 14 - trailer, 15 - bulb for contrast, 16 - channel for the needle, 17 - screw fixing the position of the trailer. The axial directions, roll and pitch angles are presented in the lower left corner.

Description of device design

A general view of the design of the device is shown in FIG. 1, and its details are shown in FIG. 2. In its general design, the support 1 is of fundamental importance, since it provides the placement and fixation of the device in the cell of the radio frequency coil of a magnetic resonance imager (not shown in Fig. 1). The upper frame 2, which has a millimeter scale 6 and provides connection to the carriage 3 by means of the groove 7, is mounted and latched onto the support 1 mounted below in the radio frequency coil; using the carriage 3, it is possible to laterally move the cylindrical rod 4. The sides of the groove 7 have inclined sides and the ability to limit the vertical displacement of the carriage 3. In the carriage 3 there is a through hole for the cylindrical rod 4. The position of the carriage 3 relative to the upper frame 2 is fixed using a bracket with an angle with an oval scale 8 and fixing screws 9. There is a hole for the cylindrical rod 4 in the bar with the angular scale 8. A holder 10 is placed between the carriage 3 and the bar with the angular scale 8. It has a screw-lock 11 for the position of the cylindrical rod 4 and a threaded hole for the screw -fixer rotation angle 12 of the rod. On the cylindrical rod 4 there is a millimeter scale 13, at the origin of which a limit switch 14 is installed. It contains a bulb for contrast 15, through which the channel 16 for the biopsy needle 5 passes. The limit switch 14 has a screw 17 for fixing the position.

The principle of operation of the device.

The proposed device using the support 1 and the upper frame 2 is fixed in a radio frequency coil. Then, the radio frequency coil, together with the fixed device, is placed on the patient’s body taking into account the region of interest and fixed with special straps to the tomograph table. Belts are included in his kit. A flask 15 is inserted into the trailer 14, filled with any contrast agent for magnetic resonance imaging in a ratio of 1: 100 with water. MP research is carried out with the inclusion in the field of view of the region of interest and the superimposed device. On MP tomograms, a flask 15 with a contrast agent is visualized, the direction of its long axis, as well as the region of interest. The direction of the long axis of the flask for contrast corresponds to the trajectory of the biopsy needle 5. In this case, the closest and safest trajectory of the biopsy needle 5 is chosen, bypassing critical organs, large vascular and neural structures. If necessary, the position of the coil and device on the patient's body can be adjusted. The necessary trajectory parameters are calculated using standard software built into the magnetic resonance imager. Parameters are needed to determine the entry point of the biopsy needle, its tilt angles, and immersion depth. Further, the obtained data is transferred to the device for adjusting the position of the bulb 15. To set the position of the bulb 15 along the X axis, the carriage 3 is moved along the groove 7 relative to the millimeter scale 6 and fixed with screws 9. To set the position of the bulb along the Y axis, the cylindrical rod 4 is extended along the Y axis relative to the millimeter scale 13 and is fixed with position fixing screws 11. To set the angle of heel in the ZX plane, the cylindrical rod 4 is rotated around the Y axis and fixed with a screw 12 relative to the angle scale on the bracket of the carriage 8. For the pitch angle settings in the ZY plane, the end 14 is rotated around the X axis and fixed with a screw 17. After the position of the bulb 15 is established and visually checked on a magnetic resonance imager, the needle 5 is inserted into the channel 16 for the needle. Next, it is immersed to the calculated depth in area of interest and perform sampling of diagnostic material.

Confirmation of the achievement of a technical result.

The proposed device is MP compatible, allows navigation in a strong magnetic field in any area of the body. It provides a secure hold with the RF coil. With its help, it seems possible to control the position of the flask for contrast and the biopsy needle on MP tomograms.

The advantages of the proposed device include the fact that its use allows you to cover a wide range of minimally invasive diagnostic procedures with high speed, accuracy and safety. The device itself is quite simple in design, convenient for placement on the patient’s body, reliable and safe to use.

Claims (1)

A device for stereotactic guidance of a biopsy needle under MRI control, containing a support, a carriage, a cylindrical rod and a biopsy needle, characterized in that the support is made in the form of a frame compatible with the upper frame having a millimeter scale and a groove with inclined walls for connecting to the carriage and providing its transverse movement, in order to fix the position of the carriage, a bar with an angular scale and carriage fixing screws are introduced, a holder of a cylindrical rod is placed between the carriage and the bar, and the carriage and the holder has fixing screws for the position of the cylindrical rod, and the bar with an angular scale has a screw that fixes its angle of rotation, in addition, the bar with an angular scale, the holder and the carriage have holes for their placement on a cylindrical rod having a millimeter scale, at the origin of which a trailer is installed, having a flask for contrast, a channel for the needle and a screw for fixing its position.

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