RU2649474C1 - Method of visualizing results of surgical treatment of juvenile angiophibromas of nasopharinx and skull basis - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to the field of medicine, namely oncology, radiation diagnostics, pediatric surgery and otorhinolaryngology, and can be used to visualize the result of surgical treatment of the juvenile angiofibromas of the nasopharynx and the base of the skull. Multispiral computed tomography with a contrast agent is performed. Three-dimensional reconstruction of the maxillofacial area is created before and after the surgical treatment from a series of images (tomograms) reflecting the arterial phase of accumulation of a contrast agent, through a graphic editor. With the help of the latter, the necessary coordinates are assigned to each reference point on the histogram of a three-dimensional image of the skull. On thus corrected three-dimensional reconstructions of the skull, its front part is removed along certain anatomical landmarks to obtain its cut in the frontal plane. After this, three-dimensional reconstruction of the skull from the tomograms corresponding to the arterial phase of contrasting is repeated, with the same graphic characteristics of the image. Sagittal section of the skull is performed from the growth of the tumor in the area of its largest component, avoiding the nasal septum entering it.

EFFECT: method ensures the objectivity and accuracy of the anatomical and topographic evaluation of tumor tissue when it is visualized, as well as an objective assessment of its results in patients with juvenile angiofibromas of the nasopharynx and the base of the skull due to qualitative and adequate planning of tactics and the course of surgical treatment.

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Description

The invention relates to medicine, namely to oncology, radiation diagnostics, pediatric surgery and ENT, and is intended to visualize juvenile angiofibromas of the nasopharynx and base of the skull.

Juvenile angiofibromas of the nasopharynx and the base of the skull (SUS and OCh) is a rare benign tumor with a predominance of the vascular component. The frequency of distribution varies from 0.05 to 0.5% of all neoplasms of the head and neck. The disease was first described by Chauveau and Friedberg et al. As a capsule-free formation consisting of an uneven network of blood vessels and a fibrous stroma. Most often, JNAs are found in male adolescents. Typical symptoms are painless nasal congestion, recurring unilateral epistaxis, and a bulky nasopharyngeal area. The tumor may have a local aggressive nature, causing extensive destruction of adjacent tissues and bone remodeling. SUS and OCH have a tendency to spread into the nasal cavity, paranasal sinuses, orbit, pterygopalatine, infratemporal fossa, periopharyngeal space and into the middle cranial fossa. Due to the predominantly vascular formation, the course of the disease can be complicated by life-threatening epistaxis, and surgical treatment is often accompanied by massive blood loss.

Currently, the main type of treatment for SAN and OCH is the surgical method. There are various methods of treatment: endoscopic, open or combined methods. The success of the surgical treatment of South Africa depends largely on the choice of access and the method of surgical treatment.

For preoperative diagnostics of SAN and OCh, multispiral computed tomography with contrast enhancement (MSCT with KU) and angiography are currently routinely used. Surgical intervention for this pathology does not always bring successful results, since it is far from always possible to evaluate the anatomical location of the tumor or the results of its resection based on the obtained research data. In the prior art, methods for visualizing SUS and OCH are not known, allowing a thorough assessment of the tumor growth picture both for planning surgical access and for assessing the radical nature of surgical interventions associated with the removal of SUS and OCH.

So, from the prior art, a method is known for visualizing juvenile angiofibromas of the nasopharynx and base of the skull (Schurova I.N. et al., Use of perfusion CT in the diagnosis of juvenile angiofibromas of the base of the skull, Medical Imaging, No. 1, 2010, pp. 17-25) consisting in the perfusion CT scan on a multispiral tomograph. A contrast preparation (iodine concentration - 350-370 mg / ml, volume - 40 ml) was injected with an injection rate of 4 ml / s using an automatic injector into the cubital vein. To quantify the microcirculation characteristics, hemodynamic tissue parameters were used: average blood flow velocity (cerebral blood flow, CBF), average blood flow volume (cerebral blood volume, CBV), mean blood transit time (mean transit time, MTT) calculated per 100 g masses of tissue substance. A significant disadvantage of this method is that the surgeons themselves, not having the ability to read multi-planar x-ray images and obtained microcirculation data, are faced with the inability to evaluate images on their own, in the absence of a radiologist with knowledge of the visualization features of SUS and OCh.

Also known from the prior art is a method for visualizing the result of surgical treatment of juvenile angiofibromas of the nasopharynx and base of the skull (Youth angiofibroma of the base of the skull / Otorhinolaryngology / Neoplasms of ENT organs, article from the Internet, found http://pactehok.ru/?cat=article&id=1918, found 02.20.2017), adopted as a prototype. The method consists in conducting multispiral computed tomography using a contrast agent and constructing the initial three-dimensional reconstruction of the maxillofacial zone before and after the operation. This method is informative, however, the interpretation of the obtained data should be carried out by a radiologist with the ability to read MSCT data with contrast enhancement and knowledge of the visualization features of SAN and OCh. In practice, such knowledge is found in doctors with specialization in diseases of the head and neck, extremely rare. General radiologists often do not possess these skills and often treat hemostatic treatment elements or scar or polypous tissue in the postoperative area as a residual component of a tumor, leading surgeons to a certain degree of confusion and vice versa, often miss small fragments of a residual tumor, which leads to the absence of timely reoperation.

Due to the absence of the capsule, the removal of the tumor as a single unit is difficult, which leads to the presence of residual components and the occurrence of relapses of the disease. Given the benign nature of the disease, it is not uncommon for a tumor to be removed fragmentarily, which makes it impossible to morphologically evaluate the edge of the resection. Surgeons themselves, lacking the ability to read multiplanar X-ray images, are faced with the inability to evaluate images on their own, in the absence of a specialist radiologist.

Thus, there is a need for a method for the result of surgical treatment of visualization of juvenile angiofibromas of the nasopharynx and base of the skull, which makes it possible to objectively and accurately perform anatomical and topographic assessment of tumor tissue.

In accordance with this, the technical result is to increase the accuracy of evaluating the result of surgical treatment of SJS and OCH using an accessible and simple method of visualization, which allows you to plan the tactics and course of surgical treatment, and objectively evaluate the results of surgical treatment of patients with this diagnosis.

To achieve the indicated technical result in the method of visualizing the result of surgical treatment of juvenile angiofibromas of the nasopharynx and the base of the skull, consisting in multispiral computed tomography using a contrast agent and constructing the initial three-dimensional reconstruction of the maxillofacial area before and after surgical treatment, a series of images is selected from the data obtained, corresponding to the arterial phase of accumulation in the program for viewing tomograms, when building a three-dimensional reconstruction Structures choose a 16-bit color graphical editor, where the density characteristics of tissues are displayed on the histogram along the abscissa axis, and the opacity of the pixel along the ordinates axis, set each reference point on the histogram as necessary coordinates, starting from denser ones, namely, for the white reference point, the corresponding density of bone tissue and contrast medium, the value of the density characteristics is set in the range of 575-577, and the value of the degree of opacity is 0.998; for the red reference point corresponding to the density of the vascular bed, the value of the density characteristics is set in the range 123-125, and the value of the degree of opacity is 0.998; for a black reference point corresponding to the density of soft tissues, the value of the density characteristics is set in the range 103-105, and the value of the degree of opacity is 0.000; for a yellow reference point corresponding to the density of less dense soft tissues, the value of the density characteristics is set in the range of 375-377, while the value of the degree of opacity is placed on the histogram line in a given range of density characteristics; after obtaining a three-dimensional reconstruction with the specified parameters, the facial part of the skull is removed and a series of image slices is performed in the frontal plane, developing a three-dimensional model of the skull in a lateral projection and drawing a line of the first section along the front edge of the pterygoid process of the sphenoid bone at the intersection of the zygomatic arch and posterior edge of the coronoid process of the lower jaw, after which they again build a three-dimensional reconstruction of the skull from images corresponding to the arterial phase in a color graphics editor with the same character image characteristics and perform a sagittal section of the image from the side of the tumor growth in the projection of its largest component, avoiding getting the nasal septum into the section.

In FIG. Figure 1 shows a 3-dimensional image after opening it in a 16-bit Color Look Up Table Editor -CLUT editor.

In FIG. 2 shows the location of control points (black, red, yellow and white).

In FIG. 3 presents clinical example 1, three-dimensional reconstruction of CT - angiography of a patient with juvenile angiofibroma of the nasopharynx and base of the skull before surgical treatment.

In FIG. 4 presents clinical example 1, three-dimensional reconstruction of CT - angiography of a patient with juvenile angiofibroma of the nasopharynx and base of the skull after surgical treatment.

In FIG. 5 presents clinical example 2, three-dimensional reconstruction of CT - angiography of a patient with juvenile angiofibroma of the nasopharynx and base of the skull before surgical treatment.

In FIG. 6. presents clinical example 2, three-dimensional reconstruction of CT - angiography of a patient with juvenile angiofibroma of the nasopharynx and base of the skull after surgical treatment.

In FIG. 7 presents clinical example 3, three-dimensional reconstruction of CT - angiography of a patient with juvenile angiofibroma of the nasopharynx and base of the skull before surgical treatment.

In FIG. 8. presents clinical example 3, three-dimensional reconstruction of CT - angiography of a patient with juvenile angiofibroma of the nasopharynx and base of the skull after surgical treatment.

The method is as follows.

A study is performed on a multispiral computed tomograph using a contrast agent before and after surgical treatment. When scanning, the arterial phase of the accumulation of the contrast agent is fixed 3-17 seconds after the administration of the contrast drug. This time interval is significant, since due to the presence of a significant vascular component associated with the fibrous stroma of the tumor, the density characteristics of the tumor vessels are hyper-intensive in the arterial phase, which makes it possible to distinguish tumor fragments and visually filter them from surrounding soft tissues, due to more significant and intensive accumulation of a contrast agent in the tumor.

In the program for viewing tomograms - DICOM files (we used Horos or Osirix for Mac OS), the patient's MSCT visualization data is loaded with contrast enhancement.

Choose a series of images corresponding to the arterial phase of accumulation of the contrast agent (for the programs used -1 CE).

Select the 3D reconstruction mode, and it has a 16-bit color graphics editor (we used the 16-bit CLUT editor (Color lookup table editor). Remove the head stop and other elements that interfere with the review and the elements present at the reconstruction (oxygen masks, tubes, etc. .).

In the open editor window, the three-dimensional image of the skull is adjusted using a histogram (gray) that displays density and transparency characteristics (mathematical conversion of Hounsfield units for a two-dimensional graphical display, where the abscissa axis is a linear graph of density characteristics, “value” is indicated on the graph, the ordinate axis - the degree of opacity of the pixel from 0 to 1, where 0 is full transparency, and 1 is full opacity, “alpha” is indicated on the graph). The principle of operation of this editor is based on the physical parameters of color images, where there are standard reference points: white (1), red (2), black (3) and yellow (4) (Fig. 1). Reference points are arranged in order of increasing the density characteristics of the image with respect to the histogram. Next, we set each point to the optimal coordinates along the abscissa and ordinates, starting from the denser ones - the white reference point (1) (bone, contrast medium) and set the value to: 575-577 and alpha: 0.998; then the red reference point (2) (vascular bed): value value: 123-125 and alpha value: 0.998; further black reference point (3) (soft tissue): value value: 103-105 and alpha value: 0.000; and the last one sets the coordinates of the yellow reference point (4) (less dense soft tissues): value value: 375-377, while the alpha value should be located on the histogram line in the specified value range (this alpha value may vary in different patients) (Fig 2 )

Next, perform a series of sections in the frontal (coronary) projection in order to determine the prevalence of the tumor process. A three-dimensional model of the skull is deployed in a lateral projection and a first cut line is drawn along the front edge of the pterygoid process of the sphenoid bone at the intersection of the zygomatic arch and the posterior edge of the coronoid process of the lower jaw. Remove the front of the skull. The rest of the three-dimensional model of the skull is again deployed with the frontal side, on which the tumor, its growth zone in the pterygopalatine fossa, and so on are evaluated. If necessary, you can continue and further perform backward sections to obtain the desired image of the tumor in the anatomical region of interest to the researcher. An important feature is the performance of sections before and after surgery in the same patient in the same plane (using the same anatomical landmarks) to compare the result of surgical treatment.

To perform a sagittal section, it is necessary to exit the 3D mode and again select a series of images corresponding to the arterial phase of accumulation of the contrast agent, then again the 3D reconstruction mode, while the program automatically opens a three-dimensional model of the skull in a graphical editor with the same filter parameters for reference points. The slice is performed from the side of tumor growth in the projection of its largest component. An important feature is a section along the nasal cavity, a minimum indentation of 3-5 mm from the midline is necessary to avoid getting the nasal septum into the section, which may block the visualization of the tumor.

When comparing the obtained images of sections in the frontal and sagittal projections before and after surgical treatment, we see the volume of the removed tumor. If there is a residual component of the tumor on three-dimensional reconstructions of CT angiography, we see a clearly contoured conglomerate of bright red color, stained with the same intensity as the arteries (Fig. 4, 6), in the absence of the latter - the operation can be considered radically performed.

In the sequential execution of this method, representative images and repeated (standardized) results are obtained, regardless of the primary location of the tumor and the type of equipment on which the study was performed (provided that the appropriate software and data range parameters of the reference points of the histogram of the three-dimensional reconstruction module are used), which correlate with a description of the radiologists. This method is available to all surgeons (including those who do not have CT semiotics), does not require the mandatory participation of a radiologist. The method allows both a preliminary assessment and a clear demonstration of the outcomes of surgical treatment of SUS and OCh.

Example 1. Patient B, 17 years old. Diagnosis: Juvenile angiofibroma of the nasopharynx. Stage IIIb by Fisch-Andrews. Condition after surgical treatment in March 2016. Continued growth.

Sick since January 2015, when there were complaints of difficulty in nasal breathing and nosebleeds. More than 1 year was observed at the ENT doctor at the place of residence with a diagnosis of rhinosinusitis, conservative treatment without effect. On an MRI of the brain from 04/04/16: MR-signs of a tumor of the nasopharynx. He was hospitalized in the head and neck pathology department with reconstructive - plastic surgery of the NNPTs DGOI named after Dmitry Rogachev for surgical treatment.

The patient provided MSCT with contrast enhancement, performed at the place of residence from 08.16.2016. Contrast: Visipack 320. The amount of contrast entered: 80 ml. Speed of introduction: 3 ml / s. Place of introduction: ulnar vein. Consent to the administration of a contrast agent is obtained. During the administration of the contrast agent, no pathological reactions were detected.

The construction of three-dimensional images in order to visualize the SAN and OCH was performed according to the proposed method (presented in Fig. 3).

A series of images was selected corresponding to the arterial phase of accumulation (1CE). A three-dimensional reconstruction of the maxillofacial zone was performed with the determination of the density characteristics of bone tissue. Using the histogram settings in the graphics editor (Fig. 3), the bone tissue was maximally selected - white reference point, value: 576 and alpha: 0.998, red reference point, value: 124 and alpha: 0.998. We carried out the filtration of the rest of the tissues, which have less than bone tissue and blood vessels, density characteristics (skin, subcutaneous fat, muscles, brain, nerves), setting the black reference point, value value: 104 and alpha value: 0.000 and yellow reference point at the value value: 376, while the alpha value was located on the histogram line. We performed a series of slices of the image in the frontal plane, unfolding a three-dimensional model of the skull in a lateral projection and drawing a line of the first slice along the front edge of the pterygoid process of the sphenoid bone at the intersection of the zygomatic arch and posterior edge of the coronoid process of the lower jaw. A sagittal section of the image was performed on the side of the tumor growth in the projection of its largest component, avoiding getting the nasal septum into the section.

According to the description of MSCT - Juvenile angiofibroma of the nasopharynx (5) with spread to the right sphenoid sinus, pterygopalatine, infratemporal fossa, with massive periopharyngeal component, destruction of the pterygoid process and large wing of the sphenoid bone with an introcranial component in the middle cranial fossa.

Treatment performed: On 08/19/2016, surgical treatment was performed in the amount of open access angiofibroma removal with transposition of the upper jaw.

The result of the examination: Histological examination of 08/24/2016. Microscopic description: in the delivered material, the formation formed by the hypocellular fibrous tissue (stained green with Masson trichrome). Within it, a few blood vessels (separate with fibrin thrombi), minor hemorrhages are visible. Anaplasia not detected. Diffuse bright nuclear expression of beta-Catenin was detected within the spindle cell component. Conclusion: Nasopharyngeal angiofibroma.

The patient is under dynamic observation.

A control MSCT study with contrast enhancement from 08.25.2016 was carried out:

Contrast: Visipack 320 50 ml. The amount of contrast entered: 80 ml. Speed of introduction: 3 ml / s. Place of introduction: ulnar vein. Consent to the administration of a contrast agent is obtained. During the administration of the contrast agent, no pathological reactions were detected.

The construction of three-dimensional images with the aim of visualizing SAN and OCH was carried out by the proposed method (presented in Fig. 4).

Conclusion: In the area of the postoperative defect, laterally from the right half of the sphenoid sinus, the residual component of the tumor, elongated, with a maximum size of 26 × 13 × 5 mm, is actively accumulating contrast in the arterial and venous phases. CT signs of a residual tumor in the right sections of the sphenoid sinus (5).

Example 2. Patient G., 9 years old. Diagnosis: Juvenile angiofibroma of the nasopharynx and base of the skull. Stage IIIb by Fisch-Andrews.

Complaints: the absence of nasal breathing, purulent discharge from the nose, fatigue, weakness, drowsiness, apnea.

Anamnesis of the disease: nasal congestion and periodic runny nose have been disturbing since May 2016. He was treated at the place of residence in the district center for sinusitis. 12/30/2016 turned to the ENT department of the GAUZ DRKB MH RT. An endoscopy of the nasal cavity and nasopharynx was performed, a neoplasm was detected, juvenile angiofibroma of the base of the skull was suspected. 01/11/2017 in the ENT department of the GAUZ DRKB MH RT, a head CT scan was performed with contrasting: Pathological nasopharyngeal neoplasm with spread: maxillary sinuses, nasal cavity, right pterygopalatine fossa, cranial cavity (middle and anterior cranial fossae) with massive destruction of the skull base bones signs of angiofibroma, it is impossible to exclude the malignant nature of the tumor). He was hospitalized in the Department of Oncology and Pediatric Surgery NNPTs DGOI for additional examination and surgical treatment.

MSCT study with contrast enhancement from 01/30/2017:

Contrast: Ultravist 370 - 50 ml. The amount of contrast entered: 55 ml. Rate of administration: 1.6 ml / s. Place of introduction: ulnar vein. Consent to the administration of a contrast agent is obtained. During the administration of the contrast agent, no pathological reactions were detected.

The construction of three-dimensional images in order to visualize the SAN and OCH was performed according to the proposed method (presented in Fig. 5).

Conclusion: In the lumen of the nasopharynx, a massive pathological formation of an irregular shape, an inhomogeneous structure due to the presence of a cystic component, with a maximum size of up to 54 × 57 × 59 mm, actively accumulating a contrast drug in the arterial phase up to a maximum of 200-210 HU, is determined. The tumor performs the entire lumen of the nasopharynx, grows into the nasal cavity with partial destruction of the nasal septum, the left maxillary sinus, cells of the ethmoid labyrinth, into the left orbit with compression of the optic nerve; Through the main sinus, it prolapses into the cavity of the suprasellar cistern of the brain, with subtotal destruction of the body and large wings of the sphenoid bone. In addition, education destroys the Turkish saddle. The pituitary gland against this background is not reliably visualized. The outer contour of the pathological formation intimately adjoins the siphon of the left ICA. In the soft tissues of the neck, paravasally, a few lymph nodes up to 12 mm in size are detected. Volumetric hypervascular formation of the nasopharynx with signs of intracranial spread (5).

Treatment: On 02/09/2017, the patient underwent transnasal endoscopic surgery to remove nasopharyngeal angiofibroma and the base of the skull under CT control using the C.A.T.S. introoperative blood reinfusion apparatus. under anesthesia, suffered satisfactorily.

MSCT - a study with contrast enhancement from 02/14/2017:

Contrast: Ultravist 370-50 ml. The amount of contrast entered: 45 ml. Rate of administration: 1.5 ml / s. Place of introduction: ulnar vein. Consent to the administration of a contrast agent is obtained. During the administration of the contrast agent, no pathological reactions were detected.

The construction of three-dimensional images with the aim of visualizing SAN and OCH was performed according to the proposed method (presented in Fig. 6).

Conclusion: the state after endoscopic transnasal removal of juvenile angiofibroma of the base of the skull from 02/09/2017. Against the background of postoperative changes, a small, hypervascular, severe, irregularly shaped area along the siphon of the left ICA is likely to remain (5).

The patient is recommended MSCT study according to the proposed method in dynamics.

Example 3. Patient O., 14 years old. Diagnosis: Juvenile angiofibroma of the nasopharynx and base of the skull. Stage II by Fisch-Andrews.

Complaints: On the absence of nasal breathing on the right, mucous discharge from the nose on the right.

Anamnesis of the disease: Since July 2016, difficulty in nasal breathing was noted, it was treated with vasoconstrictor and antihistamines. In mid-October, complete obstruction occurred for breathing of the right nasal passage. At the place of residence, a CT scan of the skull was performed on 10/17/16: a tumor of the base of the skull spreading into the maxillary sinus and into the cells of the ethmoid labyrinth. 10.24.16 operation - a biopsy of a tumor of the right nasal passage (histologically - juvenile angiofibroma), a biopsy of the upper cervical l / y on the right (of a typical structure, without MTS). He was hospitalized in the Department of Oncology and Pediatric Surgery NNPTs DGOI for additional examination and surgical treatment.

MSCT study with contrast enhancement from 11/16/2016:

The construction of three-dimensional images in order to visualize the SAN and OCH was carried out according to the proposed method (presented in Fig. 7).

Conclusion: In the lumen of the nasopharynx, a massive pathological formation of an irregular shape, an inhomogeneous structure due to the presence of a cystic component, with a maximum size of up to 54 × 57 × 59 mm, actively accumulating a contrast drug in the arterial phase up to a maximum of 200-210 HU, is determined.

The tumor performs the entire lumen of the nasopharynx, grows into the nasal cavity with partial destruction of the nasal septum, the left maxillary sinus, cells of the ethmoid labyrinth, into the left orbit with compression of the optic nerve; Through the main sinus, it prolapses into the cavity of the suprasellar cistern of the brain, with subtotal destruction of the body and large wings of the sphenoid bone. In addition, the formation destroys the Turkish saddle. The pituitary gland against this background is not reliably visualized. The outer contour of the pathological formation intimately adjoins the siphon of the left ICA.

In the soft tissues of the neck, paravasally, a few lymph nodes up to 12 mm in size are detected.

Volumetric hypervascular formation of the nasopharynx with signs of intracranial spread (5).

Treatment: On November 17, 2016, transnasal endoscopic removal of the nasopharynx angiofibroma under the control of CT navigation under anesthesia was performed and transferred satisfactorily.

MSCT study with contrast enhancement from 11/23/2016:

Contrast: Ultravist 370 - 100 ml. The amount of contrast entered: 45 ml. Rate of administration: 1.9 ml / s. Place of introduction: ulnar vein. Consent to the administration of a contrast agent is obtained. During the administration of the contrast agent, no pathological reactions were detected.

The construction of three-dimensional images in order to visualize the SAN and OCH was carried out by the proposed method (shown in Fig. 8).

Conclusion: the state after endoscopic removal of angiofibroma of the base of the skull with transnasal access using CT navigation and autoplasty from 11/17/2016.

Postoperative changes. Reliable signs of the presence of a residual tumor were not received. Inflammatory (reactive) changes in the paranasal sinuses at the scan level.

The patient is recommended MSCT study according to the proposed method in dynamics.

Claims (4)

1. A method for visualizing the result of surgical treatment of juvenile angiofibromas of the nasopharynx and base of the skull, which consists in conducting multispiral computed tomography using a contrast agent and constructing the initial three-dimensional reconstruction of the maxillofacial area before and after surgical treatment, characterized in that a series of images is selected from the data obtained, corresponding to the arterial phase of accumulation in the program for viewing tomographic data, when building a three-dimensional reconstruction, I choose A 16-bit color graphical editor, where the density characteristics of tissues are displayed on the histogram along the abscissa axis and the pixel opacity is displayed on the ordinates, set each reference point on the histogram the desired coordinates of the tissue density characteristics and the pixel opacity corresponding to this point: white reference point corresponds to the density of bone tissue and contrast medium, the value of the density characteristics in the range of 575-577, the value of the degree of opacity of 0.998; the red reference point corresponds to the density of the vascular bed, density characteristics in the range 123-125, the degree of opacity is 0.998; black reference point corresponds to the density of soft tissues, density characteristics in the range of 103-105, the value of the degree of opacity is 0.000; the yellow reference point corresponds to the density of less dense soft tissues, density characteristics in the range 375-377, the value of the degree of opacity is placed on the histogram line in a given range of density characteristics; after obtaining a three-dimensional reconstruction with the specified parameters, the facial part of the skull is removed and a series of image slices is performed in the frontal plane, developing a three-dimensional model of the skull in a lateral projection and drawing a line of the first section along the front edge of the pterygoid process of the sphenoid bone at the intersection of the zygomatic arch and posterior edge of the coronoid process of the lower jaws after which they again build a three-dimensional reconstruction of the skull from images corresponding to the arterial phase in a color graphics editor with the same image characteristics and perform a sagittal section of the image from the side of the tumor growth in the projection of its largest component, avoiding getting the nasal septum into the section. 2. The method according to p. 1, characterized in that as a program for viewing tomographic data using the program OsiriX® Viewer for Mac OS®. 3. The method according to p. 1, characterized in that as a program for viewing tomographic data using the program Horos® for Mac OS®. 4. The method according to claim 1, characterized in that the 16-bit Color Look Up Table Editor is used as the color graphics editor.

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