RU2169522C1 - Method for building image of anterior cross-shaped ligament of the knee in carrying out magnetic resonance tomography examination - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves building three reference lines on the sagittal tomogram depicting a fragment of the anterior cross-shaped ligament of the knee with slice thickness of 4 mm and step size of 1 mm. Three oblique coronary tomograms are produced. One of them, being image of the central portion of the joint, is selected. Three reference lines of 4 mm thickness and step size of 1 mm are built in correspondence to anatomical fastening of anterior cross-shaped ligament of the knee from posterointernal edge of the external femoral condyle to the anterior intercondylar fossa of the tibia to produce three oblique coronary tomograms of the knee joint one of which shows complete and not distorted image of the anterior cross-shaped ligament of the knee. EFFECT: enhanced accuracy of image; building image in single tomographic slice. 10 dwg 1 tbl

Description

 The invention relates to medicine, namely to magnetic resonance imaging and can be used to diagnose traumatic damage to the anterior cruciate ligament in orthopedic, trauma and surgical practice.

 The relevance of the problem of identifying complete, partial and intrafocal ruptures of the anterior cruciate ligament, as well as its dystrophic changes, is due to the high frequency of its ruptures during traumatic and dystrophic lesions of the knee joint.

 A known method of obtaining images of the anterior cruciate ligament using contrast arthrography. Contrast arthrography of the knee joint is performed under aseptic conditions in an X-ray room. Oxygen and an iodine-containing water-soluble contrast medium are introduced into the cavity of the knee joint, then radiographs are made. A contrast agent "smears" the intraarticular ligaments, and against the background of oxygen (gas) they become visible (RF Patent N 2142738 "Method for the diagnosis of intraarticular injuries and diseases of the knee joint." Chizhik-Poleiko AN Bul. N 35, 1999, p. 164-165).

Method disadvantage:
- there is no guarantee of obtaining an image of the anterior cruciate ligament.

 - Intra-ligamentous lesions, ligament degeneration are not visible.

- the danger of introducing infection into the joint cavity;
- the possibility of an allergic reaction to the introduction of iodine-containing contrast medium.

 - irradiation of the patient with ionizing x-ray radiation.

 A known method of pneumoarthrography of the knee joint. Gas (air, oxygen) is introduced into the cavity of the knee joint, then radiographs are made. Gas fills the joint cavity, and intraarticular ligaments become visible against its background (Vityugov I.A. New modification of the method of arthropneumography in case of damage to the menisci of the knee joint. Abstract of thesis ... Candidate of Medical Sciences. L., 1960. 15 s).

Method disadvantage:
- there is no guarantee of obtaining an image of the contour of the anterior cruciate ligament;
- Intra-ligamentous lesions, ligament dystrophy are not detected.

- the danger of introducing infection into the cavity of the knee joint;
- irradiation of the patient with ionizing x-ray radiation.

 A known method of arthroscopy of the knee joint. Arthroscopy is performed under general anesthesia. An arthroscope is inserted into the cavity of the knee joint, an anterior cruciate ligament is examined using a special optical device (Levitsky A.F., Lomnitsky O.Ya., Kosyakov A.N., Bebeshko A.V., Krisyuk S.A. Use of arthroscopy for injuries of the knee joint in children and adolescents // Orthopedics, traumatology and prosthetics: Resp. interagency collection - 1989. - Issue 19. - P. 67-68).

Method disadvantage:
- only the shape, dimensions and external contours of the anterior cruciate ligament are visible;
- Intra-ligamentous lesions and dystrophic changes are not visible;
- the danger of introducing infection into the cavity of the knee joint;
- the possibility of complications in the process of conducting general anesthesia.

 The closest solution to imaging the anterior cruciate ligament is a standard magnetic resonance imaging of the knee in the coronal, sagittal, axial planes (Crues JV, Ryu RKN Knee \\ MAGNETIC RESONANCE IMAGING / Ed. By David D. Stark, William G. Bradley, jr., 2nd ed. - St. Lous - Baltimore - Boston - Chicago - London - Philadelphia - Sydney - Toronto: Mosby Year Book, 1992. - P. 2355-2423.).

 The method for obtaining an image of the anterior cruciate ligament presented in this monograph in three standard planes: the straight line (coronal), lateral (sagittal), transverse (axial) does not allow to obtain on the MRI images a complete and undistorted image of the anterior cruciate ligament, since the anatomically anterior cruciate ligament begins from the posterior-inner surface of the lateral condyle of the femur, goes forward and medially, attaching to the anterior intercondylar fossa of the tibia (Figs. 1 and 2), i.e. goes obliquely in relation to all three planes.

 The objective of the present invention is to improve the accuracy of the image of the anterior cruciate ligament in an MRI scan, i.e. obtaining a complete and undistorted image of the anterior cruciate ligament on one tomographic section.

 The task is achieved by the fact that on a sagittal tomogram with an image of a fragment of the anterior cruciate ligament, three REF-lines are cut with a thickness of 4 mm through a gap of 1 mm, three oblique-coronal tomograms are obtained, one of them is selected with the image of the central part of the joint, on which three 4 mm thick REF lines at 1 mm intervals according to the anatomical attachment of the anterior cruciate ligament from the posterior-inner edge of the external condyle of the femur to the anterior intercondylar fossa of the tibia tee with obtaining three oblique sagittal tomograms of the knee joint, on one of which a complete undistorted image of the anterior cruciate ligament is obtained.

 Using the proposed methodology, it was possible to identify complete, partial, intracranial ruptures and degenerative changes of the anterior cruciate ligament.

 The novelty of the method.

 1. Obtaining oblique-coronal and oblique-sagittal tomograms of the knee joint allows, in contrast to the prototype, to obtain a true undistorted image of the anterior cruciate ligament.

 2. The construction of REF lines on sagittal tomograms, the central of which passes through the anatomical attachment of the anterior cruciate ligament from the posterior-inner surface of the external condyle of the femur to the anterior intercondylar fossa of the tibia, provides a true image of the anterior cruciate ligament without distortion.

 3. Selected 3 sections with a thickness of 4 mm through a gap of 1 mm, since the thickness of the anterior cruciate ligament does not exceed 2.0 cm.

 The invention is illustrated by the attached figures and MRI tomograms, where in FIG. Figures 1-7 show tomographic sections of the knee joint with the image of the anterior cruciate ligament normal, with complete rupture and dystrophy. On them anatomical structures are marked with numbers. Under the number 1 is the patella, 2 is the external condyle of the thigh, 3 is the anterior cruciate ligament. 4 - the posterior cruciate ligament, 5 - the tibia, 6 - the inner condyle of the femur, 7 - the anterior intercondylar fossa of the tibia, 8 - the mid REF line.

 The method of MRI research of the anterior cruciate ligament with suspected rupture or dystrophy is as follows.

 The study was carried out on a VECTRA2 magnetic resonance imager from GENERAL ELECTRIC with a magnetic field voltage of 0.5 T using a SURE-76 knee coil in standard sagittal and two non-standard oblique-coronal and oblique-sagittal planes using SPIN-EXO and GRE T1 and T2 (table) of weighted images (VI) with a tomograph step of 4 mm through a 1 mm gap with the parameters indicated in the table.

 A SURE-76 knee coil is mounted on the table deck of the magnetic resonance imager. The patient is laid on his back on the table deck so that the examined knee joint is placed in the center of the coil. The limb is in a slightly bent position at an angle of 10 degrees. The patient is fixed to the table deck to ensure complete immobility. Then the table with the patient gets into the magnet tunnel. On the control panel, technical parameters are typed to obtain an image of the knee joint in the standard sagittal plane in the sequences T1, T2 (see table). From the obtained sagittal tomograms, select the tomogram in which at least one fragment of the anterior cruciate ligament is visible. On this tomogram, three REF lines are constructed with a section thickness of 4 mm through a gap of 1 mm, since the thickness of the anterior cruciate ligament is about 2.0 cm. Three tomograms are obtained in a non-standard oblique-coronal projection. From the obtained three oblique-coronal tomograms, one is selected that shows the central part of the joint, the posterior-internal part of the external condyle of the femur and the anterior intercondylar fossa, to which the anterior cruciate ligament is attached. On this tomogram, three REF-lines are cut with a section thickness of 4 mm through a gap of 1 mm, corresponding to the anatomical attachment of the anterior cruciate ligament from the posterior-inner edge of the external condyle of the femur to the anterior intercondylar fossa of the tibia. Three tomograms are obtained in the oblique sagittal plane in sequences T1 and T2 (see table) of weighted images. On one of these tomograms, the anterior cruciate ligament is necessarily visualized in an undistorted form. They study the type, direction, structure, measure the width, density of the anterior cruciate ligament.

 This made it possible to absolutely accurately diagnose traumatic injuries (full and partial, intracranial ruptures), dystrophic lesions of the anterior cruciate ligament and produce surgical treatments appropriate to the type of injury.

 CLINICAL EXAMPLES

 1. Patient R. born in 1954 aimed at a study at the center for radiation diagnostics of the municipal city clinical hospital N 1 of Novokuznetsk from a trauma center by a trauma doctor with a diagnosis of suspected damage to the inner meniscus, the inner-lateral ligament and the anterior cruciate ligament of the left knee joint. She had a history of the injury she received a year ago when she was skiing, clinging to a Buran. Fell on her left knee, tucking her leg. She felt a sharp pain, about which she was taken to a doping center. In the emergency room, X-rays were examined and there were no traumatic injuries of the knee joint. During the year, it was treated conservatively: blockades, intra-articular injections of Kenalog. The acute pain is gone, but the dull, constant pains persist, while walking the leg seems to be "exposed" and bent. On examination, the left knee joint is thickened, movements in it are limited, and lame when walking. A standard MRI tomographic study of the joint was performed, a rupture of the internal meniscus, deforming arthrosis with pronounced dystrophic changes in the articular cartilage, menisci, posterior cruciate ligament, fat folds, dystrophic cyst of the external meniscus and a large amount of fluid in the joint cavity were found. A clear image of the anterior cruciate ligament was not obtained on any of the standard tomograms produced. From the obtained standard sagittal tomograms, the tomogram was selected in which a small upper fragment of the anterior cruciate ligament was visible. On this tomogram, three REF lines are constructed with a section thickness of 4 mm through a 1 mm gap to produce tomograms in a non-standard oblique-coronal projection. Of the three oblique-coronal tomograms obtained, the one that accounted for the central part of the joint and the posterior-inner edge of the external condyle of the femur and the anterior intercondylar fossa of the tibia were visible. On this tomogram, three REF lines are aligned according to the anatomical attachment of the anterior cruciate ligament from the posterior-inner edge of the external condyle of the femur to the anterior intercondylar fossa of the tibia to obtain tomograms in the oblique sagittal plane. Three oblique sagittal tomograms are produced in T1 and T2 weighted images. On one (central) tomogram, the detachment of the anterior cruciate ligament from the anterior fossa of the intercondylar elevation of the tibia with the displacement of the ligament upward was clearly defined. The ligament was unevenly thinned to 1.0 cm, a signal of increased intensity emanated from it, which indicated a pronounced dystrophic process that developed as a result of the injury. The patient underwent arthroscopy, on which the separation of the anterior cruciate ligament of the left knee joint was confirmed, and she was operated on.

 2. Patient P., born 1970 He was sent to the center for radiation diagnostics of the municipal city clinical hospital No. 1 to prevent rupture of the anterior cruciate ligament of the left knee joint, post-traumatic deforming arthrosis. He suffered a joint injury six months ago at a gym class at the institute. The partner threw him from a height, fell to his knee, felt pain, but did not seek medical help. A month later, due to pain in his knee, he went to the doctor. It is treated conservatively, but the pains not only do not go away, but become stronger, there is instability in the joint, periodically “wedges”. On examination, the joint is thickened, movements are moderately limited, painful. On the survey radiographs of the left knee joint, traumatic injuries were not determined. A standard MRI scan of the joint was performed. Found: a defect in the articular cartilage of the patella, rupture of the inner meniscus, small bone growths on the articular ends of the femur, tibia, patella and a large amount of fluid in the joint cavity and the anteroposterior inversion. The anterior cruciate ligament was barely visible on one of the sagittal tomograms. On this sagittal tomogram, three REF lines are built up with a thickness of 4 mm at an interval of 1 mm for the production of tomograms in a non-standard oblique-coronal projection. Of the three oblique-coronal tomograms obtained, one was selected that fell on the central part of the knee joint and on which the posterior-inner edge of the external condyle of the femur and the anterior intercondylar fossa of the tibia were visible. On this tomogram, three REF-lines are cut with a thickness of 4 mm at a 1 mm interval, corresponding to the anatomical attachment of the anterior cruciate ligament from the posterior-inner edge of the external condyle of the femur to the anterior intercondylar fossa of the tibia to obtain tomograms in the oblique sagittal plane. Three skew-sagittal tomograms of the knee joint were produced in T1 and T2 weighted images. A central oblique sagittal tomogram clearly visualized a dystrophically altered, unevenly thinned (up to 0.8 cm) anterior cruciate ligament, in the center of which an iso-intensive linear signal was determined on a T2 weighted tomogram, indicating an intracircular rupture.

 Thus, the method for examining the anterior cruciate ligament is highly informative and non-invasive. Allows the doctor to timely determine the tactics of treatment of traumatological and surgical patients. The method is proposed for widespread implementation in practice.

Claims (1)

 A method of obtaining an image of the anterior cruciate ligament of the knee joint during magnetic resonance imaging in the coronal and sagittal planes, characterized in that three REF lines with a section thickness of 4 mm through a 1 mm gap are constructed on a sagittal tomogram with an image of a fragment of the anterior cruciate ligament, and three oblique coronal tomograms, select one of them with the image of the central part of the joint, on which three REF-lines with a thickness of 4 mm are built at an interval of 1 mm according to the anatomical attachment of the per a single cruciate ligament from the posterior-inner edge of the external condyle of the femur to the anterior intercondylar fossa of the tibia to obtain three oblique sagittal tomograms of the knee joint, on one of which a complete undistorted image of the anterior cruciate ligament is obtained.

Images