RU2714082C1 - Diagnostic technique for gunshot wounds of the spinal column using magnetic resonance and x-ray computed tomography - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: present invention refers to medicine, namely to diagnostics. A diagnostic technique for spinal gunshot wounds is performed by means of magnetic resonance and X-ray computed tomography by dividing the patient's preoperative, preoperative and postoperative stages. Preoperative MRI examination is performed with contrast enhancement; preoperative stage involves X-ray CT examination of area of interest and postoperative stage of X-ray CT examination of area of interest and MRI examination with contrast enhancement. Additionally, the stage of the patient's examination is introduced - the intake, where the X-ray CT examination is carried out in the "whole body" mode, according to the results of which all foreign bodies of metal density are removed, and the MRI examination, wherein the MRI analysis protocol for all steps includes obtaining locators in three mutually perpendicular planes, obtaining a series of shots in the STIR (Short Tau Inversion Recovery) pulse sequence in the coronal plane, obtaining T2-weighted images in the sagittal and axial planes, and in the preoperative and postoperative steps with contrast enhancement additionally include obtaining T2-weighted volumetric images in the axial plane, obtaining T1-weighted images with selective suppression of the adipose tissue signal by chemical shift based on Dixon's method in the sagittal plane to assess inflammatory changes before contrast enhancement, obtaining post-contrast T1-weighted images in sagittal, axial and coronal planes in fat-suppression mode based on the Dickson method.

EFFECT: technical result provided by the disclosed invention is higher clinical effectiveness.

1 cl, 1 dwg, 5 tbl, 2 ex

Description

This invention relates to medicine, namely to radiation diagnostics.

Gunshot wounds of the spine are among the most severe combined injuries that are in the field of interest for neurosurgery, traumatology and radiation diagnostics, as they give mortality rates as high as 70% and lead to severe disability of the victims [Aryan, N.E. Gunshot wounds to the spine in adolescents. Division of Neurosurgery, University of California, San Diego, California, USA / H.E. Aryan, A.P. Amar, B.M. Ozgur et al. // Neurosurgery. 2005. - Vol. 57, No. 4. - P. 74852; Kathleen A. McCarroll Imaging traumatic brain injury, II Russian-American Conference "Actual Issues of Neurosurgery, Neuroanesthesiology and Resuscitation" 2003, 67-70].

The prevalence of this injury in peacetime is about 29.4 per 10,000,000 of the population in developed countries and up to 50 per 1,000,000 in developing countries. In conditions of armed local conflicts, the frequency of gunshot injuries of the spine and spinal cord during local armed conflicts increases by 4-5 times, reaching 3.5% [Kathleen A. McCarroll Imaging traumatic brain injury, II Russian-American Conference “Actual issues of neurosurgery, neuroanesthesiology and resuscitation "2003, 67-70].

The management tactics of such patients is determined by the nature of the wound, the degree of compression and the level of damage to the spine and spinal cord, the presence of combined injuries of adjacent organs and tissues [Trufanov G.E. Radiation diagnosis of head and spine injuries 2006; 193-202; Levchuk A.L. Gunshot thoracospinal wounds: dissertation 2007; 80-118; Mohammed, K.M. Elhazh Gunshot wounds of the spine and spinal cord: dissertation 2010; 43-47]. High-quality diagnostics allows you to choose the most optimal tactics of surgical and conservative treatment, thereby significantly increasing the effectiveness of treatment and avoiding severe consequences [Alan, M. Levine Spine trauma. Epidemiology perspective problem / M. Alan // Polytrauma patient. Philadelphia: WB Saunders, 1998. -P. 668; Ackery, A. Global Perspective on Spinal Cord Injury Epidemiology / A. Ackery, C. Tator, A. Krassioukov // J neurotrauma. 2004. - Vol. 21, No. 10. - P. 1355-1370]. The lack of necessary information before the operation can lead to formidable complications [Reinke, M. Brown-Sequard syndrome caused by a high velocity gunshot injury: a case report / M. Reinke, Y. Robinson, W. Ertel et al. // Spinal cord. 2007. - Vol. 45, No. 8. - P. 579-82].

The main prognostic criterion for such wounded is the anatomical integrity of the spinal cord [Alan, M. Levine Spine trauma. Epidemiology perspective problem / M. Alan // Polytrauma patient. Philadelphia: WB Saunders, 1998. -P. 668].

A known method of chest x-ray [Levchuk A.L. Gunshot thoracospinal wounds: dissertation 2007; 80-118; Mohammed, K.M. Elhazh Gunshot wounds of the spine and spinal cord: dissertation 2010; 43-47], in which it is possible to obtain primary data on possible damage to the spine based on the identification of foreign bodies in the immediate vicinity of it or in the spinal canal itself. However, these data do not specify the nature of the injuries, it is not always possible to identify traumatic injuries of bone structures, to accurately determine the anatomical position and depth of the location of bone fragments and foreign bodies, and also to establish the trajectory of a wounding projectile. Gunshot wounds are combined injuries, accompanied by trauma to neighboring organs and tissues.

Also known method [Aryan N.E., Amar A.R., Ozgur V.M. et al. Gunshot wounds to the spine in adolescents. Neurosurgery. 2005; 57] X-ray computed tomography (PKT) of the spine, which allows various types of image processing, obtaining the necessary projections and building three-dimensional models, assessing the state of all organs and tissues of the region of interest, thereby providing extremely reliable information about the state of bone and adjacent structures. At the same time, these data are insufficient to assess the condition of the spinal cord and its membranes, with the exception of cases of hematomyelia.

Objective visualization of the spine is performed using a number of different research methods.

An analogue of the proposed method is magnetic resonance imaging (MRI) of the spine [General recommendations of primary and repeated descriptions of CT, MRI, x-ray studies; Radiological Research Description Protocol Templates. Volume 2. Computer tomography; The "Management of Radiology Report Templates" (MRRT) - RSNA's Reporting Initiative (http://www.radreport.org)]. The standard protocol for MP-examination of the spine includes obtaining T1-weighted images (T1VI) and T2-weighted images (T2 VI) in the sagittal (SAG) and axial (AX) planes, as well as a series of images in the coronal plane using a pulse sequence (IP ) with suppression of the signal from adipose tissue by means of a short inversion-recovery time (STIR).

Table 1 presents the standard protocol for MRI scans of the spine (cervical, thoracic, lumbosacral).

The disadvantage of this method is the poor visualization of the membranes and roots of the spinal cord, wound canal, as well as the inability to detect inflammatory changes.

The closest analogue of the proposed method is described in [Ulyanov V.A. Magnetic resonance imaging in the diagnosis of gunshot wounds of the spine // Medical imaging. 2015. 3. S. 10-16]. In this paper, the informational content of magnetic resonance imaging (MRI) with contrast enhancement (CT) is evaluated to diagnose inflammatory changes in patients with gunshot wounds. In the course of the work, it was shown that the introduction of a contrast medium allows to detect violations of the blood-brain barrier, as well as dynamic observation of the inflammatory process. Some pulsed sequences expanding the standard protocol of MRI studies are indicated, which form T1VI with KU, T2VI with KU using the FatSat (FS), STIR, fat suppression function. However, this method has several disadvantages, in particular, it does not provide the ability to detect metal objects in the patient’s body, which must be removed to safely perform an MRI scan. In addition, the prototype does not indicate the sequence of diagnostic measures that must be observed when analyzing the patient’s condition from the moment of admission to the postoperative stage, and the modes of recording volumetric images in the axial plane with high spatial resolution and differentiation of tissues, including neural structures, are not presented , and allowing to identify inflammatory changes.

The technical problem solved by the claimed invention is to develop a single standard for the diagnosis of patients with gunshot wounds of the spine on an X-ray computer and magnetic resonance imaging (MRI), including CT, with an assessment of damage to the neural structures of the spinal cord.

Achievable technical result is the creation of a universal standardized research protocol, which makes it possible to reduce the effect of artifacts from metal objects, to best visualize the spinal cord, its membranes and roots, identify inflammatory changes, thereby allowing to choose the most optimal tactics of surgical and conservative treatment, significantly increase the effectiveness treatment and avoid serious consequences.

The inventive method represents the optimal diagnostic algorithm for admission of patients with gunshot wounds of the spine and contains a universal standardized protocol for MP-research.

The claimed technical result is provided by the developed algorithm of diagnostic measures performed upon admission of a patient with a gunshot wound of the spine to the hospital, and is achieved due to the following essential features that distinguish the claimed invention from the above analogues:

- separation of the stages of the study of the patient into the following: admission, preoperative, preoperative, postoperative,

- conducting at the stage of receipt of the CT in the mode of "whole body" and MRI,

- carrying out at the preoperative stage MRI with KU for the purpose of dynamic observation,

- conducting at the preoperative stage of the RCT area of interest,

- carrying out in the postoperative stage of the CT, areas of interest and MRI with CT,

- MRI scan in compliance with the order of PI, including the standard part of the study and a special one (at each stage of the algorithm of diagnostic measures, except for the preoperative one), including a list of PIs that provide the following images:

1. T1VI in the sagittal plane with selective suppression of the signal from adipose tissue by chemical shift based on the Dixon method (T1 SAG Dixon) or FatSat (T1 SAG FS);

2. T1VI with suppression of the signal from adipose tissue in three planes after MRI with KU (T1 SAG Dixon (/ FS) with KU, T1 COR Dixon (/ FS) with KU, T1 AX Dixon (/ FS) cKY);

3. Volumetric T2VI in the axial plane 3D-Fiesta - SSFP (FIESTA) AX, where SSFP - Steady State Free Precession, FIESTA - Fast Imaging Employing Steady-state Acquisition.

Obtaining T1VI images in the sagittal plane and with contrast enhancement is partially used in the prototype, but it is essential that in the claimed invention, these images are obtained in a certain sequence and use selective signal suppression from adipose tissue by chemical shift based on the Dickson method.

In FIG. 1 schematically presents an algorithm for the sequence of diagnostic measures for patients with gunshot wounds of the spine. The method is as follows:

1. Upon admission to a patient with a gunshot wound of the spine, the following is performed:

- RKT in the "whole body" mode

All foreign bodies of metal density, represented by wounding shells in the form of bullets and fragments of mines, found on CT, are removed before an MRI.

- modified MRI protocol, i.e. a protocol that includes a standard part and a special one.

With the modified MRI protocol, the state of neural structures, intervertebral discs, and paravertebral soft tissues are assessed. The modified MRI scan protocol includes:

a. Obtaining locators in three mutually perpendicular planes (SAG-sagittal, COR - coronal, AX - axial) is a standard part of the protocol.

b. Obtaining a series of images in the STIR IP in the coronal plane is a standard part of the protocol.

c. Obtaining T2VI in the sagittal and axial planes is a standard part of the protocol.

d. Obtaining T2-weighted volumetric images in the axial plane is a special part of the protocol.

e. Obtaining T1VI with selective suppression of the signal from adipose tissue according to the chemical shift based on the Dixon or FatSat method in the sagittal plane to assess inflammatory changes (Tl SAG Dixon (/ FS)) before the KU.

f. Obtaining post-contrast T1VI in the sagittal, axial and coronal planes in the mode of fat reduction based on the Dixon or FatSat method (Tl SAG Dixon (/ FS) with KU, T1 COR Dixon (/ FS) with KU, T1 AX Dixon (/ FS) with KU) -special part of the protocol.

2. At the preoperative stage, it is necessary to perform only MRI with CT for the purpose of dynamic monitoring until the inflammatory process is stabilized. MRI with CT is performed using a modified protocol for MRI scanning.

3. At the preoperative stage, when planning surgical intervention, only the CT of the area of interest is performed.

4. In the postoperative phase is performed:

- RKT in order to assess the state of bone structures and stabilizing metal structures (if any)

- MRI with KU in order to assess the integrity of the dural sac, stump of the spinal cord, roots and spinal nerves, as well as post-inflammatory changes. MRI with CT is performed using a modified protocol for MRI scanning.

Table 2 presents the modified protocol for MRI scan of the spine (cervical, thoracic, lumbosacral).

The technical parameters of the PI used in the above embodiment of the claimed invention are presented below.

Table 3 presents the technical parameters of the PI forming T2VI in the sagittal plane. Table 4 presents the technical parameters of the PI forming T1VI with selective suppression of the signal from adipose tissue in the sagittal plane. Table 5 presents the technical parameters of STIR PI in the sagittal plane.

Thus, a preferred embodiment of the invention is as follows:

All patients at the stage of admission to the hospital perform an RKT in the "whole body" mode. All foreign bodies of metal density, represented by wounding shells in the form of bullets and fragments of mines, found on the CT scan, are removed before an MRI scan.

In this case, RKT studies are performed on a multislice X-ray computer tomograph (Toshiba Aquilion 64). At all stages of the diagnosis, except for the preoperative one, MRI is performed on a device with a magnetic field induction of 1.5 T (Toshiba Atlas) with a standard matrix 16-channel transmitter-receiver coil for the lumbar spine using a modified protocol for MRI scanning.

Laying the patient in a supine position, centering the laser beam on the navel.

As a contrast agent, a half-molar gadolinium containing the drug gadodiamide is used at a concentration of 0.5 mmol / ml at the rate of 0.2 ml / kg body weight.

They begin an MRI scan with locators in three mutually perpendicular planes (SAG — sagittal, COR — coronal, AX — axial).

A modified MRI scan protocol is set up, consisting of a standard and a special part.

The standard part of the protocol is performed, including obtaining series of images of STIR IPs in the coronal plane and IPs forming T2VI in the sagittal and axial planes.

Include in the scanning protocol special PIs used to obtain T2-weighted volumetric images in the axial plane, T1VI with selective suppression of the signal from adipose tissue by chemical shift based on the Dickson or FatSat method in the sagittal plane, as well as post-contrast images in the sagittal, axial and coronal planes in the mode of fat reduction by the method of Dixon or FatSat.

For optimal visualization of neural structures, T2-weighted volumetric images in the axial plane, 3D-Fiesta, are used, which have high spatial resolution and excellent differentiation of tissues, including neural structures, and also make it possible to detect inflammatory changes. The block of slices is set according to the received images in the sagittal or in the coronal plane. When constructing three-dimensional reconstructions, neural structures are clearly visualized against the background of hyperintensive cerebrospinal fluid. Postprocessing allows you to get three-dimensional images in new orthogonal planes.

They use PIs that form T1VI with selective suppression of adipose tissue by chemical shift based on the Dixon or FatSat method to suppress the signal from adipose tissue, reduce chemical shift artifacts, and improve visualization of contrast enhancement and tissue differentiation. In the study of hemorrhages, as well as in MRI with KU, it is preferable to choose the regime of fat suppression in favor of the Dixon method than FatSat. The disadvantages of IP FatSat are its great sensitivity to magnetic field inhomogeneity, uneven suppression of the signal from adipose tissue with a large field of view, outside the center of the image and in the presence of metallic foreign bodies. Suppression of the signal from fat based on longitudinal relaxation time (STIR PI) is less preferable in view of the different T1 values of the hemorrhagic component depending on the elapsed time from the wound, and KU is able to accumulate in unchanged adipose tissue.

Thus, obtaining a series of T1VI images with suppression of the signal from adipose tissue by a chemical shift in the sagittal plane prior to contrast enhancement (T1VI SAG Dixon (/ FatSat)) and in three orthogonal planes after administration of a contrast medium (Tl SAG Dixon (/ FS) with KU, T1 COR Dixon (/ FS) with KU, T1 AX Dixon (/ FS) with KU), allows to detect inflammatory changes. The pathological amplification of the MP signal in post-contrast images may be the first, and sometimes the only, manifestation of epiduritis, spondylitis, and discitis.

Post-contrast images in three planes also make it possible to evaluate the configuration and structure of the wound canal (pulsating zone, granulation zone, actively storing a contrast medium).

Below are examples of the use of the proposed method, confirming its diagnostic effectiveness.

Example No. 1

Patient N, 31 years old, gunshot bullet through penetrating wound of the abdomen.

Upon admission to the patient, according to the algorithm (Fig. 1), a CT scan was performed in the “whole body” mode, which allowed to reliably confirm the absence of foreign bodies of metal density before MRI.

Using MRI, an analysis of latent damage to neural structures was performed. The state of the substance of the spinal cord was evaluated, with emphasis on the proximal sections, its integrity, the presence of foci of myelopathy, the condition of the spinal nerves, and also the integrity of the dural membrane. A severe contusion of the cauda equina roots, rupture of ligaments, fragmentation and dislocation of the intervertebral discs were established.

Since gunshot wounds belong to high-energy injuries, except for the projectile damage zone, the injury was accompanied by tissue damage by a lateral shock wave and the presence of an extensive zone of molecular concussion. In this connection, the state of proximal and distal, from the level of direct damage to the projectile, intervertebral discs was evaluated.

MRI made it possible to assess the state of paravertebral soft tissues, including massive fluid stains due to cerebrospinal fluid, mainly on impulse sequences with signal suppression from adipose tissue, and also to conduct dynamic observation after puncture of stains.

At the preoperative stage, it is only necessary to have an MRI with CT to stabilize the inflammatory process. Surgery on the spine before stabilization of the inflammatory changes is impractical, and only MRI with KU can evaluate these changes. The inflammatory process was manifested in the form of changes in neural structures, such as epiduritis and discitis, manifested in the form of amplification of the MP signal in post-contrast images.

The use of contrast enhancement made it possible to determine the violation of the blood-brain barrier, that is, to establish the presence of an inflammatory process, as well as to conduct a dynamic observation. Due to the fact that the signal characteristics from adipose tissue on T1VI have a hyperintensive MR signal that makes it difficult to detect inflammatory changes, the study was conducted in the mode of fat suppression (T1VI FS).

The change in the MP signal from the contusionally changed proximal intervertebral disc in dynamics was expressed as a decrease in the height of the disc and an increase in the signal from its structure.

Carrying out MRI with KU revealed gunshot osteomyelitis of L3-5 vertebral bodies.

Clinically: lower pronounced peripheral paraparesis to plegia in the feet. Dysfunction of the pelvic organs in the central type.

The following surgical interventions were performed for this patient:

1. Right-sided hemicolectomy, resection of the small intestine, inter-intestinal anastomosis end-to-end, terminal ileostomy, tamponade of the peritoneal space.

2. Laparotomy, separation of adhesions, removal of ileostomy, resection of the ileum, ileotransverse anastomosis, drainage of the abdominal cavity.

3. Trocar epicystostomy.

4. After stabilization of the inflammatory changes, the patient underwent L4-L5 laminectomy, revision of the area of the gunshot fracture, decompression of the dural sac, wound drainage.

Example No. 2 Patient N, 26 years old

Gunshot bullet blind wound of the cervical spine.

Upon admission to the patient, a whole-body CT was performed during which a gunshot comminuted fracture of the body, arch, transverse and articular process of C5 and the body of C6 vertebrae was established, a bullet in the area of the unvertebral joint C5-6 on the left, a gunshot wound to the trachea, cervical esophagus non-penetrating bullet blind wound of the left lumbar region, multiple comminuted wounds of the right and left thigh, right foot, right lumbar region. Carrying out MRI with KU (after bullet removal) revealed a severe spinal cord injury with a gross violation of conduction function in the C5, C6 spinal cord.

At the preoperative stage, CT of the area of interest was performed for planning surgical intervention, evaluating paravertebral fragments, sequestral cavities, and sclerosis zones.

In the postoperative phase, an RCT of area of interest was carried out in order to assess the state of bone structures, stabilizing metal structures, as well. MRI with CT in order to assess the state of neural structures and postoperative changes.

The following surgical interventions were performed:

1. Tracheostomy, PHO wounds of the right thigh, right hand, right foot.

2. C5 corpectomy, decompression of the spinal cord at the level of C5-6 vertebrae, removal of bone fragments, foreign body (bullet), followed by anterior stabilization by the ADD system at the level of C4-6 vertebrae.

3. Secondary surgical treatment of the lower back, right thigh, hand, foot; removal of a foreign body (bullet) in the lumbar region.

4. Revision of the postoperative wound of the neck, suturing wounds of the esophagus, drainage of the wound.

Claims (1)

A method for the diagnosis of gunshot wounds of the spine using magnetic resonance and x-ray computed tomography by dividing the stages of the study of the patient into preoperative, preoperative, postoperative, conducting at the preoperative stage an MRI study with contrast enhancement, conducting at the preoperative stage an CT scan of the area of interest and postoperative stage of the RCT study of the area of interest and MRI studies with contrast enhancement, characterized in that it further input The stage of the patient’s research is the admission, which conducts an RCT study in the “whole body” mode, according to the results of which all foreign bodies of metal density are removed, and an MRI study, while the protocol of an MRI study for all stages involves obtaining locators in three mutually perpendicular planes, obtaining a series of images in a pulsed sequence STIR (Short Tau Inversion Recovery) in the coronal plane, obtaining T2-weighted images in the sagittal and axial planes, and in the preoperative and postoperative At the opposite stages, with contrast enhancement, additionally include obtaining T2-weighted volumetric images in the axial plane, obtaining T1-weighted images with selective suppression of the signal from adipose tissue according to the chemical shift based on the Dickson method in the sagittal plane to evaluate inflammatory changes before contrast enhancement, and obtaining post-contrast T1-weighted images in the sagittal, axial and coronal planes in the mode of fat reduction based on the Dickson method.

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