RU2140203C1 - Method of three-dimensional echography in differential diagnosis of amatio retinae and membranous formations in vitreous body in eye injuries - Google Patents

Abstract

FIELD: medicine, ophthalmology. SUBSTANCE: method includes differentiation of membranous formations in vitreous body and amatio retinae by character of brightness histograms made on selected from three-dimensional mass of frontal acoustic cross-sections that makes it possible to enhanced diagnostic information content of ultrasonic examination in determination of indications and selection of tactics of surgical treatment of eye penetrating injury. EFFECT: higher diagnostic information content of three-dimensional echography of eye by detection alongside with topography of pathologic focus, its echographic structure for differential diagnosis of membranous formations of vitreous body and amatio retinae in penetrating injury of eye.

Description

 The invention relates to the field of medicine - ophthalmology - and is intended for the differential diagnosis of retinal detachment and membranous formations of the vitreous body with traumatic injuries of the eyeball.

 Differential diagnosis of membranous formations of the vitreous body and retinal detachment during eye injuries is a complex task of ultrasound, since the echographic signs of one and the other pathology can be so varied that they can only be distinguished by their characteristic configuration, connection with the optic disc and the membranes of the eye. But these signs are secondary and by no means always allow us to confidently judge the presence or absence of retinal detachment. In addition, in case of violation of the perpendicular arrangement of the ultrasonic sensor to the test object, which is inevitable with a complex configuration of focal pathology, “moving” echo signals arise, which in turn complicate the interpretation of the results.

 At the same time, in order to solve the question of indications and the choice of surgical intervention tactics, it becomes necessary to increase the information content of an echographic study with the obligatory indication of the presence or absence of retinal detachment.

 A known method of examining the eye by three-dimensional ultrasound imaging by introducing a series of acoustic sections into the coordinate system of a three-dimensional image (DBDowney, DANicolle, M.F. Levin, A.Fenster - "Three-dimensional ultrasound imaging of the eye". - Eye - 1996, n. 10, (Pt. 1), p. 75-81). The method allows you to get an idea about the topography of complex forms of intraocular pathology with penetrating eye injury with the ability to assess the configuration of the exfoliated retina and membranous formations in the vitreous.

 The disadvantage of this method of three-dimensional ultrasound imaging of the eye is the inability to differentiate membranous formations in the vitreous body and retinal detachment in gross forms of vitreoretinal pathology, which in most cases accompany penetrating eye injury. It is possible to exclude or confirm the presence of retinal detachment only by secondary signs (features of the configuration of pathological structures, their connection with the optic nerve and the lining of the eye), which is unacceptable in those situations where an exact indication of the nature of the pathology is necessary. In this case, when determining the indications for surgical intervention and choosing the tactics for its implementation.

 The technical result of the invention is the ability to increase the diagnostic information content of three-dimensional ultrasound of the eye by identifying along with the topography of the pathological focus, its echographic structure for the differential diagnosis of membranous formations of the vitreous body and retinal detachment with penetrating eye injury.

 The technical result is achieved by the fact that in a three-dimensional array of acoustic sections, a direction is chosen that is perpendicular to the location of the vitreoretinal pathology sections that are subject to structural analysis, and a series of frontal acoustic sections is performed with subsequent construction of brightness histograms that characterize the retinal detachment and the membranous formations in the vitreous body.

 The method is as follows: using a fixing device that has three degrees of freedom and is mounted on an ophthalmic table, the ultrasonic sensor in the positioner rotation device is immersed in a transparent plexiglass bath filled with warm saline (25-30 degrees) and installed on the eyelids with the eye open. Celsius), which is well tolerated by the eye.

 During the study, the scanning head of the sensor performs sectorial movements at a speed of 30 vibrations per second, which ensures the formation of two-dimensional acoustic scans in real time. At the same time, the sensor performs a complete rotational movement in the positioner, performing meridional scanning at high speed - 180 acoustic sections for 12 seconds with the registration of the position of each section relative to the eye in the range of 0.3 angular degrees, which corresponds to the resolution of the method and allows you to most accurately restore the volume array the examined eye.

 The video signals from the video output of the ultrasonic diagnostic device through the image input module are sent to a high-speed personal computer, for example, IBM PC / AT - 486, 66 MHz with expanded RAM (not less than 20 Mb), where they are electronically processed to ensure the accumulation of acoustic sections and the formation of three-dimensional data array.

 Then, in a three-dimensional array, a direction is chosen that is perpendicular to the location of the areas of vitreoretinal pathology that are subject to structural analysis and a series of frontal acoustic sections are performed. The perpendicular arrangement of frontal acoustic sections in relation to vitreoretinal pathological formations is necessary to exclude "moving" echo signals that make it difficult to interpret the results of the study.

 The resulting series of frontal acoustic sections are alternately presented on a monitor screen for selecting images to be further processed. Then, histograms of the brightnesses of the selected sections are constructed and the retinal detachment and membranous formations in the vitreous are differentiated by the ratio of the amplitude height to its width. Retinal detachment is characterized by a histogram with high amplitude and small width. Moreover, the range of oscillations is relatively small - from 7.9 to 8.3, which is due to the stable brightness and high level of contrast characteristic of echo signals from a detached retina. Films in the vitreous humor are characterized by a histogram with a low amplitude and a wide base with a wide range of oscillations - from 1.6 to 5.2, which is due to the echographically heterogeneous nature of the vitreous pathology in case of eye injuries.

 A specific example of the method: Patient K., 34 years old. He addressed about a sharp decrease in visual acuity in the right eye after an industrial injury. Hospitalized with penetrating eye injury. Visual acuity of the right eye is the count of fingers in the face. During biomicroscopy on the sclera in the para-limbal region, a scar with partial prolapse of the membranes, gross opacities in the vitreous body were recorded. Ophthalmoscopy is impossible due to the lack of reflex from the fundus.

 An ultrasound study of the internal environment of the injured eye in the ultrasound department was performed. Using one-dimensional, two-dimensional and three-dimensional sonography revealed coarse membranous cords inside the eye. Retinal detachment cannot be ruled out. Frontal acoustic sections located perpendicular to the pathological structures inside the eye were isolated from the three-dimensional data array for differential diagnosis of membranous formations in the vitreous body and retinal detachment. On the frontal acoustic sections selected for structural analysis, luminance histograms are constructed. The ratio of the height of the brightness amplitude to its width did not exceed 2.5, which is typical for membranous formations in the vitreous. The patient underwent vitrectomy, which confirmed the absence of retinal detachment (in case of suspected retinal detachment, this operation is contraindicated). Visual acuity at discharge - 0.2.

 Thus, the invention allows to differentiate between membranous formations in the vitreous body and retinal detachment according to the nature of the brightness histograms performed on frontal acoustic sections selected from a three-dimensional array, which makes it possible to increase the information content of an echographic study when determining indications and choosing the tactics of surgical treatment of penetrating eye injury.

Claims (1)

 A method of three-dimensional ultrasound imaging in the differential diagnosis of retinal detachment and membranous formations in the vitreous body due to eye injuries, including electronic summation of a series of acoustic sections, characterized in that in the three-dimensional array, the direction perpendicular to the location of the areas of vitreoretinal pathology is selected, and frontal acoustic sections are selected for it, produced the construction of histograms of brightness for these sections, determine on them the ratio of the height of the amplitude to its width and when the ratio is 7, 9 - 8.3 note the presence of retinal detachment, and with a ratio of 1.6 - 5.2 - membranous formations.