RU2741212C1 - Diagnostic method of malignant lesions of peripheral zone of prostate - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to ultrasonic diagnostics and oncourology, and can be used for diagnostics of malignant lesions of peripheral zone of prostate (P). Intravenous ultrasound contrast preparation is administered to the patient; contrast-enhanced ultrasonic examination (CEUSE) is performed. Areas of interest are determined, process of rate of absorption and removal of ultrasonic contrast agent is recorded. At least one curve of dependence of intensity of reflected echo signal on time from the beginning of the study is plotted. Derived curve is used to determine the ultrasonic contrast preparation washout angle. With leaching angle α ≤ 61.5° presence of malignant focal formation of the peripheral zone of the prostate is diagnosed. If the washing angle α > 61.5° absence of malignant focal formation of peripheral zone of prostate is diagnosed.

EFFECT: method provides the diagnostics of prostate peripheral zone focal lesions in the course of conducting the CEUSE by the quantitative assessment of the focal lesions perfusion by plotting the "time-intensity" curves and the washing-out angle calculation.

1 cl, 1 tbl, 3 ex, 17 dwg

Description

The invention relates to medicine, namely to ultrasound diagnostics and oncourology, and can be used to diagnose malignant focal formations of the peripheral zone of the prostate gland during contrast-enhanced ultrasound examination (hereinafter referred to as CUUSI).

According to the International Agency for Research on Cancer at WHO, prostate cancer (PCa) is the second most common malignant tumor in the male population of the planet. In 2018, more than a million new cases of the disease were detected worldwide. It is the most commonly diagnosed cancer among men in more than half of the world's countries. In the Russian Federation in 2017, prostate cancer was in second place in the structure of oncological diseases in men.

Today, standard screening for patients with suspected PCa includes digital rectal examination (DRE), prostate-specific antigen (PSA) levels, ultrasound (US) and ultrasound-guided systemic prostate biopsy (RV) if suspected.

Ultrasound is the standard method of RV imaging today. B-mode data is insufficient for differential diagnosis of focal formations of the peripheral zone of the pancreas. In this regard, the number of false-negative results of systemic biopsy under ultrasound guidance in the diagnosis of prostate cancer is 30-45%. Thus, there is a need to improve the ultrasound signs of prostate cancer.

From the prior art, there is a known method for differential diagnosis of prostate cancer (see RF patent No. 2147418 C1, IPC А61В 8/00, 04/20/2000), which discloses a method in which transrectal ultrasound examination (TRUS) with color Doppler mapping (CDC) and by the density of the vascular plexus and the average diameter of the vessels in different zones of the prostate, the vascularization index is determined, by the value of which a focal formation in the pancreas is diagnosed.

The disadvantages of this method are: limited CDC in the diagnosis of the microvasculature, subjective dependence on the operator in the interpretation of the data obtained. With the help of Doppler mapping, it is possible to register blood flow in vessels up to 1 mm in size (the average size of the visualized pancreas vessels in this method was 1.7 mm), while the size of true tumor microvessels is in the range of 10-50 μm. Thus, the diagnosis of prostate cancer by this method is based not on true tumor angiogenesis, but on larger tumor vessels.

From the prior art, a method for differential diagnosis of prostate pathology is known (see patent for invention of the Russian Federation No. 2488352 C1, IPC А61В 8/00, 01/25/2012), in which to obtain diagnostic data on the presence of pancreatic lesions, the nature of the pathological process, the degree of its spread in the organ, the gray-scale mode (B-mode) and Doppler techniques are used, the malignancy index is determined, by the value of which the presence of malignant focal formation of the pancreas is ascertained.

The disadvantage of this method is that the acquisition of diagnostic data is based on B-mode and Doppler techniques, which are limited in information content.

The closest to the proposed method is a method of differential diagnosis of pancreatic pathology in which CUUSI is performed, the area of interest is determined, a quantitative analysis is carried out, for this, curves of the dependence of the intensity of absorption of the contrast agent on time are plotted, using software, diagnostic parameters are determined that provide an additional assessment of the pathology RV (see “Clinical application of contrast enhanced ultrasound to diagnose benign prostatic hyperplasia)). Jingfang Shi, Xiaohua Yin, Rong Xu, Yingchun Wang, Lin Jin, and Weiwei Gao, Diagnostic Pathology, 01 Jul 2014, 9: 133).

The disadvantage of this method is that the ultrasound of the pancreas was carried out by transabdominal access, through the filled bladder. Due to the significant remoteness of the pancreas from the scanning surface of the sensor, the informative value of such access in detecting pathological changes is low, while this method cannot be considered sufficiently accurate and reliable when conducting differential diagnostics of focal pancreas.

The objective of the invention is to develop an additional quantitative criterion for the diagnosis of malignant focal formations of the peripheral zone of the pancreas according to CUUSI data and to determine the need for targeted biopsy in the area of interest.

The technical result of the claimed invention is to improve the accuracy and objective diagnosis of malignant focal formations of the peripheral zone of the pancreas during CUUSI, by creating a new criterion for quantitative assessment of the perfusion of malignant focal formations by constructing time-intensity curves) and calculating the washout angle.

The specified technical result is achieved by the fact that the method for diagnosing malignant focal formations of the peripheral zone of the prostate gland, which consists in the fact that the patient is injected intravenously with an ultrasound contrast agent, a contrast-enhanced ultrasound study is performed, the zones of interest are determined, the process of the rate of absorption and excretion of an ultrasound contrast agent is recorded at least one curve of the dependence of the intensity of the reflected echo signal on the time from the beginning of the study, the value of the washout angle of the ultrasound contrast agent is determined according to the constructed curve, and the presence or absence of malignant focal formation of the peripheral zone of the prostate gland is diagnosed based on the obtained value.

In addition, in the method for diagnosing malignant focal lesions in the peripheral zone of the prostate gland, to diagnose the presence or absence of malignant focal lesions in the peripheral zone of the prostate gland, the obtained value of the washout angle of the ultrasonic contrast agent is compared with the angle α = 61.5 °.

Thus, when using this method, it is possible to diagnose malignant focal formations of the peripheral zone of the pancreas with high accuracy. This method can be used in various medical institutions of various profiles, for example, in oncological centers in patients with a primary negative biopsy of the peripheral zone of the pancreas, but with persistent suspicions of a malignant process to determine the area of interest and conduct targeted biopsy.

The method for diagnosing malignant focal formations of the peripheral zone of the pancreas is illustrated by the following figures:

fig. 1 - curve of dependence "time-intensity",

fig. 2 - curves obtained during the ROC analysis,

fig. 3, 4 - echograms of the prostate gland of patient K. (example No. 1),

fig. 5 - echogram of the prostate KUUSI in the post-processing mode of the "time-intensity" curve from the intact peripheral zone of the right lobe, patient K. (example No. 1),

fig. 6 - echogram of the prostate KUUSI in the mode of plotting the time-intensity curve in the peripheral zone of the left lobe in the area of focal formation, patient K. (example No. 1),

fig. 7 - echogram of CUUS of the prostate gland in the mode of plotting the time-intensity curve in the central zone of the right lobe, patient K. (example No. 1),

fig. 8, 9 - echograms of the prostate gland of the patient Ch. (Example No. 2)

fig. 10 - echogram of CUUS of the prostate in the mode of plotting the time-intensity curve in the peripheral zone of the focal formation of the right lobe, patient Ch. (Example No. 2),

fig. 11 - echogram of the prostate KUUSI in the mode of plotting the "time-intensity" curve in the peripheral intact zone of the left lobe, patient Ch. (Example No. 2),

fig. 12 - echogram of the prostate gland KUUSI in the mode of plotting the time-intensity curve in the central zone of the right lobe, patient Ch. (Example No. 2),

fig. 13, 14 - echograms of the patient's prostate gland,

fig. 15 - echogram of KUUSI of the prostate gland in the mode of plotting the time-intensity curve in the peripheral zone of the focal formation of the left lobe of the prostate, patient B (example No. 3),

fig. 16 - echogram of KUUSI of the prostate gland in the mode of plotting the time-intensity curve in the peripheral intact zone of the right lobe of the prostate gland, patient B (example No. 3),

fig. 17 - ultrasound image of the prostate gland in the mode of plotting the time-intensity curve in the central zone of the left lobe, patient B (example No. 3).

A method for the diagnosis of malignant focal formations of the pancreas according to CUUSI data is as follows.

Contrast-enhanced ultrasound is a rapidly developing technology in recent years. This method is effective and accurate in diagnosing malignant focal formations of internal organs, in which the diagnosis is quite objective.

In the Russian Federation, the drug "Sonovue" ("SonoVue", BRACCO SUISSE, SA (Switzerland)) is used as a contrast ultrasound drug - the only registered UCP approved for use since August 5, 2013. It is a suspension of microbubbles of sulfur hexafluoride with an average diameter of 1.9-2.5 micrometers stabilized by a shell of phospholipids, comparable in size to erythrocytes (1 μm = 0.001 mm). UCP circulate exclusively in the blood and do not go beyond the vascular bed, and due to its size, the microcirculatory system passes freely. The microbubble shell is a phase interface with a significant level of pressure resistance. Due to this property, a strong back reflection of ultrasonic waves occurs, accompanied by an increased visualization of microbubbles. Under the influence of ultrasound, the microbubbles begin to vibrate especially strongly if the frequency of the emitted ultrasonic wave corresponds to the resonant frequency of the microbubbles. In the case of using the standard ultrasound mode, the signal amplification due to the use of a contrast agent is approximately 30 dB, which corresponds to a 1000-fold increase. This allows images to be obtained that are sensitive enough to detect a single microbubble and therefore visualize the true microcirculation of blood flow. Since microbubbles are rapidly destroyed at a normal frequency of ultrasonic waves, modern devices implement a special contrast mode with a low mechanical index (MI) (less than 0.2), which allows preventing their premature rupture, maintaining oscillations of microbubbles and visualizing them in real time. Oscillating microbubbles create a specific echo with non-linear characteristics and specific frequencies. An ultrasound machine with the presence of a contrast mode allows detecting this special echo signal from microbubbles, despite a significant decrease in its intensity (compared to conventional ultrasound mode) and distinguishing it from a linear tissue signal. On average, after 11 minutes, 90% of the administered dose of sulfur hexafluoride, as part of the drug "Sonovyu", is removed from the blood with exhaled air. With its high diagnostic efficiency, it is safe and characterized by isolated cases of side effects.

The development of PCa into a clinically significant disease is accompanied by pathological angiogenesis. The microvascular network of malignant focal formation of the peripheral zone of the pancreas consists of 2 types of vessels: existing from the surrounding normal tissue, into which the tumor has invaded, and new microvessels resulting from pathological neovascularization. New tumor vessels have an irregular tortuous course, irregular diameter, arteriovenous shunts, blind ends, many trifurcations, there is no smooth muscle layer in their wall and a poorly expressed pericyte coverage. These features of the structure of tumor vessels explain the increased inflow of MCB microbubbles in the malignant focal lesion and the rapid outflow from it in comparison with intact parenchyma or with adenomatous tissue.

Thus, in the process of conducting CUUZI, the process of absorption and excretion of the PCP is recorded, which significantly increases the sensitivity and accuracy of ultrasound in assessing the perfusion of tissues and focal formations of the peripheral zone of the pancreas.

Considering the small nature of the vessels of the pancreas parenchyma and the rate of changes, it is not always possible to visually record the rapid inflow and washout of the PCP. Therefore, an urgent task is to study the quantitative parameters of perfusion of focal changes in the pancreas according to CUUSI data, which can improve the accuracy of diagnostics of malignant focal formations of the peripheral zone of the pancreas and reduce the dependence of the study associated with the interpretation of the results.

The method is carried out using KUUZI, which is carried out transrectally. With this access, the gland is separated from the sensor by the rectal wall, adipose tissue, and fascial septum.

Patients with suspected malignant focal lesions in the peripheral zone of the pancreas (elevated PSA levels more than 4 ng / ml, the presence of seals according to DRE results) were assessed using TRUS and Doppler techniques for lesions with suspected malignancy. The presence of a hypoechoic, hypervascular formation in the peripheral zone with indistinct contours was considered as ultrasound signs of a malignant focal lesion in the pancreas. The choice of the zone of interest is based on the data of the B-mode and Doppler techniques. After determining the zone / zones of interest, CUUS is performed on an ultrasound machine in a contrast mode with a low MI value using an intracavitary multifrequency transducer (4-7 MHz).

Before the study, the Sonovyu UCP is diluted in 5 ml of 0.9% saline (NaCl solution) to obtain 5 ml of the finished drug mixture. For one study, 2.4 ml of the ready-made mixture of the drug is used, sufficient for examining the pancreas in one projection. During KUUZI, the drug "Sonovyu" is administered intravenously by bolus, through a pre-installed intravenous catheter of size G 20. Next, 5 ml of saline is injected in the same way, according to the manufacturer's recommendations. For scanning, a transverse plane was selected with the maximum inclusion of a suspicious area in the peripheral zone. The probe was kept motionless at constant parameters during the study. Continuous visualization of CUUZI is performed immediately after injection of PCD within 3 minutes. In the process of conducting QUUZI, the process of absorption and excretion of the UCP is recorded, for this, the process of the study is recorded. KUUZI video clips are saved in digital image format.

Further, a qualitative and quantitative analysis of the results of the KUUZI is performed. For this, when carrying out diagnostics, the resulting video clip is studied in detail. Qualitative analysis includes an assessment of the contrast intensity in the area of interest: the rate of accumulation of the PCD, an assessment of the clarity of the contours of the focal formation and the subsequent washing out of the PCD in it. Based on the results of a qualitative analysis of a digital image during the QUUS process, a zone suspicious of a malignant process is determined - a zone of interest - an area of rapid accumulation of microbubbles of the UCP and rapid washing out in the peripheral zone of the pancreas without clear contours.

The next step is quantitative analysis, which includes plotting time-intensity curves and calculating the washout angle. Time-intensity curves are built automatically using the software of the ultrasound machine, where the X-axis displays the time from the start of the study in seconds (sec.), And the Y-axis shows the intensity of the reflected echo signal in decibels (dB).

Curves "time-intensity" are plotted in 3 zones of interest for each patient: 1) in the peripheral zone of the pancreas, with suspicion of a focal lesion (malignant process), 2) in the symmetrical area of the peripheral zone of the pancreas, without visible changes, 3) in the central part of the prostate gland. These three areas of interest were highlighted with query windows of the same diameter.

The next step is to determine the washout angle in all three zones of interest. To do this, use a transparent free online protractor available on the worldwide information network "Internet", access mode: https://ginifab.com/feeds/angle_measurement/.

The time-intensity curve image from these zones is saved in JPEG format. A transparent online protractor is applied to the resulting image. The center of the protractor is set to the PI point, one side of the angle is perpendicular to the abscissa axis, the other side of the angle connects the PI point and the DT / 2 point on the curve, the angle between them is defined as the washout angle (a) of the ultrasonic contrast agent. You can build several curves at one point with the calculation of the washout angle and the subsequent calculation of the average value.

An example of the resulting time-intensity curve is shown in FIG. one,

Where:

- α - washout angle (C °, degree);

- PI (peak intensity / dB) - maximum contrast enhancement intensity;

- ТТР (time to peak / sec) - time until the moment when the intensity of accumulation of PCD in the area of interest reaches its maximum value;

- DT / 2 (descending time / sec) - the time during which the intensity of the contrast enhancement falls to half the maximum value;

- AUC (area under the curve, dB / sec) - area under the curve.

The use of the method for diagnosing malignant focal formations of the peripheral zone of the pancreas makes it possible to more accurately assess the nature of the perfusion of focal formations in the peripheral zone of the pancreas during the QUSUI of the pancreas and to determine the need for biopsy in the area of interest.

We examined groups of patients with suspected malignant focal formations of the peripheral zone of the pancreas (total PSA level above 4 ng / ml, compaction according to DRE, changes in the peripheral zone according to TRUS), determined the area of interest, and performed CUUS. The process of the rate of accumulation and excretion of PCD was recorded. The curves of the relationship "time - intensity" were built, according to which the qualitative and quantitative analysis of the results of CUUZI was carried out retrospectively.

During the qualitative analysis, the video clips of the KUUZI were evaluated and the zone of interest was determined, i.e. the area suspicious of a malignant process is a site of rapid accumulation of microbubbles of the PCD and rapid washout in the peripheral zone of the pancreas without clear contours. When conducting a quantitative analysis, according to the constructed curves "time-intensity", the value of the washout angle was calculated, on the basis of the obtained value, the presence or absence of malignant focal formation of the peripheral zone of the prostate was diagnosed.

According to the data of systemic biopsy and targeted biopsy from the zone of interest, malignant focal lesions of the peripheral zone of the pancreas (PC) were detected in the first group of examined patients, in the second group of patients - benign focal lesions of the peripheral zone of the pancreas or without suspicion of the presence of any formations in the pancreas.

The analysis established a statistically significant difference in the washout angle values measured in the area of malignant focal lesion in the peripheral zone of the pancreas, in the area of benign focal lesion in the peripheral zone of the pancreas, in the area of the peripheral zone of the pancreas without visible changes, and in the central area of the pancreas. To analyze the interaction of the sensitivity and specificity of the diagnostic test of the washout angle, ROC analysis was used, an intergroup comparison of the washout angle indicators in the above zones was carried out. It was found that the best information content of the washout angle in the diagnosis of prostate cancer was obtained when comparing the zones of malignant focal formation of the peripheral zone of the prostate with an intact peripheral zone.

Was determined the threshold value of the washout angle α = 61.5C °.

The sensitivity of the test "α = 61.5C ° - prostate cancer" was 93.8%, the specificity was 83.3%.

To diagnose the presence or absence of malignant focal formation of the peripheral zone of the pancreas, the calculated value of the washout angle obtained as a result of the study in each patient is compared with the threshold value of the washout angle α = 61.5C °.

With a value of the washout angle α≤61.5C °, the presence of a malignant focal formation of the peripheral zone of the pancreas is diagnosed

When the value of the washout angle α> 61.5 ° C, the absence of malignant focal formation of the peripheral zone of the pancreas was diagnosed.

The results of the statistical analysis are shown in FIG. 2 and table 1.

where, Se - sensitivity, Sp - specificity, AUC - area under the curve.

It should be noted that in patients in whom the value of the washout angle was α≤61.5 °, an additional targeted biopsy was performed from the area of interest with suspected malignant focal formation of the peripheral zone of the pancreas, in order to clarify the diagnosis and confirm the diagnosis made using the stated way.

Thus, the claimed method improves the diagnostic accuracy by differentiating cancer from other prostate pathology (benign hyperplasia, chronic prostatitis) using a new criterion for quantitatively assessing the perfusion of focal lesions by constructing time-intensity curves and calculating the washout angle.

The implementation of the diagnostic method for QUUZI will be considered in the following examples. Example # 1.

FIG. 3 and FIG. 4 shows echograms of the prostate gland of patient K. in B-mode and CDC mode. The patient's age is 69 years, the total PSA level is 20 ng / ml, the gland volume is 42 ml. On the periphery of the left lobe of the prostate gland, there is a hypoechoic lesion measuring 13 × 9 mm, without clear contours, hypovascular in the CDC mode. The preliminary diagnosis was a focal formation of the peripheral zone on the left with suspected malignancy (PCa).

The next stage was KUUZI. In the post-processing mode, the time-intensity curves were analyzed from the focal formation of the peripheral zone of the left lobe, from the symmetrical area of the unchanged peripheral zone of the right lobe and from the central parts of the gland.

FIG. 5 shows an echogram of the CUUS of the prostate in the "time-intensity" curve construction mode in the peripheral zone of the intact right lobe. A transparent online protractor is superimposed on the echogram, its center is set to the PI point, a perpendicular is lowered from it to the abscissa axis, the other side of the angle is directed to the DT / 2 point on the curve. The washout angle in this case is 71 ° C.

FIG. 6 shows an echogram of the CUUS of the prostate gland in the mode of plotting the time-intensity curve in the peripheral zone of the left lobe in the area of focal formation. A transparent online protractor is superimposed on the echogram, its center is set to the PI point, a perpendicular is lowered from it to the abscissa axis, the other side of the angle is directed to the DT / 2 point on the curve. The washout angle in this case is 44 ° C.

FIG. 7 shows an echogram of the CUUS of the prostate in the mode of plotting the time-intensity curve in the central zone of the right lobe. A transparent online protractor is superimposed on the echogram, its center is set to the PI point, a perpendicular is lowered from it to the abscissa axis, the other side of the angle is directed to the DT / 2 point on the curve. The washout angle in this case is 70 ° C.

According to targeted biopsy data from a focal lesion of the left lobe of the prostate gland, a malignant focal lesion was diagnosed - acinar adenocarcinoma, with a Gleason score of 4 + 3 = 7 points, and no tumor growth was found in the right lobe of the prostate.

Example # 2.

FIG. 8 and FIG. 9 shows the echograms of the prostate gland of the patient Ch. In B-mode and CDC mode. The patient was 71 years old, the total PSA level was 10.5 ng / ml, the gland volume was 64 ml. On the periphery of the right lobe of the prostate gland, near the interlobar sulcus subcapsularly, there is a hypoechoic, hypovascular focus of 6 × 4 mm in size, with a clear outline. The preliminary diagnosis is a focal change in the peripheral zone on the right with suspected malignancy (PCa).

The next stage was KUUZI. In the post-processing mode, the time-intensity curves were analyzed from the focal formation of the peripheral zone of the right lobe, from the symmetrical area of the unchanged peripheral zone of the left lobe and from the central parts of the gland.

FIG. 10 shows an echogram of the CUUS of the prostate in the mode of plotting the time-intensity curve in the peripheral zone of the focal formation of the right lobe. A transparent online protractor is superimposed on the echogram, its center is set to the PI point, a perpendicular is lowered from it to the abscissa axis, the other side of the angle is directed to the DT / 2 point on the curve. The angle in this case is 40 ° C.

FIG. 11 shows an echogram of the CUUS of the prostate gland in the "time-intensity" curve construction mode in the peripheral intact zone of the left lobe. A transparent online protractor is superimposed on the echogram, its center is set to the PI point, a perpendicular is lowered from it to the abscissa axis, the other side of the angle is directed to the DT / 2 point on the curve. The washout angle in this case is 66 ° C.

FIG. 12 shows an echogram of the CUUS of the prostate gland in the time-intensity curve construction mode in the central zone of the right lobe. A transparent online protractor is superimposed on the echogram, its center is set to the PI point, a perpendicular is lowered from it to the abscissa axis, the other side of the angle is directed to the DT / 2 point on the curve. The washout angle in this case is 68 ° C.

According to a targeted biopsy from a focal lesion of the right lobe of the prostate gland, a malignant lesion was diagnosed - acinar adenocarcinoma according to Gleason 4 + 3 = 7 points, in the rest of the systemic sampling there is no tumor growth.

Example No. 3.

FIG. 13 and FIG. 14 shows echograms of the prostate gland of patient V. in B-mode and CDC mode. The patient's age is 66 years, the total PSA level is 7.09 ng / ml, the gland volume is 80 ml. On the periphery of the left lobe of the prostate gland, a moderately hypoechoic area 16 × 8 mm in size, with an indistinct contour, hypovascular in the CDC mode is noted subcapsularly. The preliminary diagnosis was a focal formation of the peripheral zone on the left with suspected malignancy (PCa).

The next stage was KUUZI. In the post-processing mode, the time-intensity curves were analyzed from the focal formation of the peripheral zone of the left lobe, from the symmetrical area of the unchanged peripheral zone of the right lobe and from the central parts of the prostate gland.

FIG. 15 shows an echogram of the CUUS of the prostate in the mode of plotting the time-intensity curve in the peripheral zone of focal formation of the left lobe of the prostate. A transparent online protractor is superimposed on the echogram, its center is set to the PI point, a perpendicular is lowered from it to the abscissa axis, the other side of the angle is directed to the DT / 2 point on the curve. The angle in this case is 66 ° C.

FIG. 16 shows an echogram of the CUUS of the prostate gland in the mode of plotting the time-intensity curve in the peripheral intact zone of the right lobe of the prostate gland. A transparent online protractor is superimposed on the echogram, its center is set to the PI point, a perpendicular is lowered from it to the abscissa axis, the other side of the angle is directed to the DT / 2 point on the curve. The washout angle in this case is 77 ° C.

FIG. 17 shows an echogram of the CUUS of the prostate in the mode of plotting the time-intensity curve in the central zone of the left lobe. A transparent online protractor is superimposed on the echogram, its center is set to the PI point, a perpendicular is lowered from it to the abscissa axis, the other side of the angle is directed to the DT / 2 point on the curve. The washout angle in this case is 64 ° C.

According to biopsy data, no tumor elements were found, signs of benign focal formation of the peripheral zone - glandular-muscular hyperplasia (adenoma) of the prostate gland - are noted.

Claims (1)

A method for diagnosing malignant focal formations of the peripheral zone of the prostate gland, which consists in the fact that the patient is injected intravenously with an ultrasound contrast agent, a contrast-enhanced ultrasound examination is performed, the zones of interest are determined, the process of the rate of absorption and excretion of an ultrasonic contrast agent is recorded, at least one intensity dependence curve is plotted of the reflected echo signal from the time from the beginning of the study, according to the constructed curve, the value of the washout angle of the ultrasonic contrast agent is determined, and if the washout angle is α≤61.5 °, the presence of a malignant focal formation of the peripheral zone of the prostate is diagnosed, with the value of the washout angle α> 61.5 ° diagnose the absence of malignant focal formation of the peripheral zone of the prostate gland.

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