阅读说明：本技术 短暂味觉刺激后磁共振扩散加权成像为主的评价方法 (Evaluation method mainly based on magnetic resonance diffusion weighted imaging after transient taste stimulation ) 是由 徐亮 范国华 金丹 陆宽 于 2021-09-13 设计创作，主要内容包括：本发明涉及放射性涎腺损伤评价技术领域,尤其涉及短暂味觉刺激后磁共振扩散加权成像为主的评价方法,针对现有的评价方法准确率较低,味觉刺激后动态DW-MRI方法不一致,且通常研究采用的维生素C片含服法易导致测量误差的问题,现提出如下方案,其中包括以下步骤：S1：味觉刺激DW-MRI检查前准备,S2：采用柠檬汁短暂味觉刺激法,本发明的目的是采用柠檬汁短暂味觉刺激作为刺激方法,避免了因维生素C片个体溶解差异而导致的测量误差,可以更稳定地反映味觉刺激后各涎腺ADC值的动态变化趋势,也有助于今后研究的可比性和可重复性,且缩短了柠檬汁在口中的保持时间,减少了唾液过多引起吞咽动作而导致的伪影。(The invention relates to the technical field of radioactive salivary gland injury evaluation, in particular to an evaluation method mainly based on magnetic resonance diffusion weighted imaging after transient taste stimulation, and provides the following scheme aiming at the problems that the accuracy of the existing evaluation method is low, the dynamic DW-MRI method after taste stimulation is inconsistent, and the commonly-used buccal method of vitamin C tablets is easy to cause measurement errors, wherein the evaluation method comprises the following steps: s1: preparation before taste stimulus DW-MRI examination, S2: the invention aims to adopt the lemon juice transient taste stimulus method, adopts the lemon juice transient taste stimulus as the stimulus method, avoids the measurement error caused by the individual dissolution difference of vitamin C tablets, can more stably reflect the dynamic change trend of ADC values of various salivary glands after taste stimulus, is also beneficial to the comparability and repeatability of future research, shortens the retention time of the lemon juice in the mouth, and reduces the artifacts caused by swallowing action caused by excessive saliva.)

1. An evaluation method based on magnetic resonance diffusion weighted imaging after transient taste stimulation, which is characterized by comprising the following steps:

s1: preparation before taste stimulation DW-MRI examination: selecting subjects and uniformly preparing the selected subjects before the DW-MRI examination of taste stimulation;

s2: the lemon juice transient taste stimulation method is adopted: injecting lemon juice into the mouth of a subject, keeping for 10s, and then swallowing;

s3: dynamic DW-MRI examination technique after transient gustatory stimulation: carrying out examination after transient taste stimulation on the selected experimental object by adopting an MRI technology;

s4: DW-MRI post-treatment method: processing the DW-MRI original image through software, and drawing a data change curve;

s5: measurement of saliva flow rate: acquiring flow rate and other saliva data of saliva at different times through calculation;

s6: evaluation mechanism: the salivary gland function and the xerostomia of the patient are evaluated more comprehensively and individually by adopting a salivary flow rate measurement and xerostomia grading and scoring method;

s7, periodic detection and repeated evaluation: stimulating again at intervals after the first brief gustatory stimulation, evaluating again, and comparing the evaluation results.

2. The method of claim 1, wherein in step S1, subjects of different sex, age group and suffering from nasopharyngeal carcinoma are selected for radiotherapy in the same time period by the same technique, and the subjects after radiotherapy are prepared before DW-MRI examination, wherein all examinations are performed in the same time period every day and water is prohibited 1 hour before each scan.

3. The method of claim 1, wherein 5ml of shaken and mixed 100% lemon juice is injected into the mouth of the subject and kept 10S before swallowing, and the subject is deprived of food water after swallowing before performing dynamic DW-MRI examination after the transient taste stimulus.

4. The method of claim 1, wherein in step S3, 16-channel head and neck combined phased array coils are used, all patients are examined by DW-MRI of anterior, posterior parotid, submandibular and sublingual glands, and are scanned in supine position, the scan range includes bilateral parotid, submandibular and sublingual glands, wherein DW-MRI uses EPI sequence, the scan parameters are TR4000ms, TE55ms, FOV180mm, matrix 256 × 512, excitation times 1, layer thickness 6mm, interval 1mm, scan layers 18, b values 0 and 1000S/mm²And before and after radiotherapy scanning parameters need to be kept consistent, 1 DW-MRI scanning of parotid gland, submandibular gland and sublingual gland is firstly carried out in a resting state for each examination as a reference, and MR DWI scanning is carried out on three salivary gland rows for 10 times after gustatory stimulation, wherein the starting time of dynamic scanning is 30s after stimulation starts, the scanning time of single MR DWI scanning is 1min30s, and the interval is 30 s.

5. The method of claim 1, wherein the DW-MRI raw images are processed by Extended MR word Space software of Philips in S4, wherein the outline of the parotid gland, submandibular gland and sublingual gland is delineated on each image by ROI method, the SI of each salivary gland in each image is measured, the SI of each glandular organ is averaged, and the measured SI is substituted into the formula to obtain resting and stabbing imagesPost-stimulus ADC value, the formula is: ADC ═ ln (SI)₁/SI₂)]/(b₂-b₁) Wherein b is₁And b₂For corresponding b value, SI₁And SI₂The signal intensity of the b value is taken, the maximum ADC value increase rate after stimulation is (maximum ADC value after stimulation-ADC value before stimulation)/ADC value before stimulation, Tmax is the time from the beginning of gustatory stimulation to the maximum ADC value after stimulation, the ADC value of each gland on one side, the maximum ADC value IR and Tmax after stimulation are calculated, the average value is taken on two sides, an ADC value-time change curve is drawn according to the ADC value of each salivary gland at each time point before and after stimulation, the peak value corresponds to Tmax and the maximum ADC value after stimulation, the average resting ADC value before radiotherapy and after radiotherapy, the maximum ADC value after stimulation and the maximum ADC value after stimulation are respectively recorded, the difference rate of the resting ADC value of each gland and the maximum ADC value after stimulation before and after radiotherapy is calculated, and the calculation formula of the difference rate of the resting ADC value of each gland and the maximum ADC value after stimulation before radiotherapy and before radiotherapy is: rADC_{Salivary gland}(％)＝(ADC_{After radiotherapy}–ADC_{Before radiotherapy})/ADC_{Before radiotherapy}。

6. The method of claim 1, wherein the flow rate of saliva at different times and other saliva data are obtained by calculation, wherein the resting saliva flow rate is calculated by a lap method, wherein the lap method is a method of weighing a lap of 1.0cm x 1.2cm in size in advance, placing the lap at the mouth of each salivary gland, collecting the lap at 5min, weighing the lap, measuring the mixed saliva amount of the right and left parotid glands and the submaxillary hypoglossal gland at the resting time, adding the lap and the parotid gland to obtain the whole gland saliva amount, calculating the stimulated saliva flow rate by a lemon juice stimulation method, calculating the resting and stimulated saliva flow rate in g/min, and calculating the saliva flow rate change (%) after the saliva flow rate stimulation/resting saliva, and recording the resting saliva flow rate of parotid gland, sublingual jaw gland and whole gland before and after radiotherapy, the saliva flow rate after stimulation and the change rate of the saliva flow rate after stimulation, and calculating the resting saliva flow rate of parotid gland, sublingual jaw gland and whole glandThe difference between the fluid flow rate and the post-stimulation saliva flow rate before and after radiation treatment is formulated as: saliva flow rate difference (%) (saliva flow rate)_{After radiotherapy}Salivary flow Rate_{Before radiotherapy}) Flow Rate of saliva_{Before radiotherapy}。

7. The method of claim 1 wherein the step of S6 comprises using salivary flow rate measurement and grading dry mouth disease, wherein the grading dry mouth disease comprises grading toxic dry mouth disease for tumor therapy, grading visual simulation, and questionnaire.

8. The method of claim 7 wherein the criteria for grading oncological toxic xerostomia are graded by static saliva flow rate values, wherein mild xerostomia is judged by no change in dietary habits and a static saliva flow rate of > 0.2ml/min, moderate xerostomia is judged by a change in dietary habits and a static saliva flow rate of 0.1-0.2ml/min, no oral feeding, nasogastric tubing or intravenous nutrition is required, and severe xerostomia is judged by a static saliva flow rate of < 0.1 ml/min.

9. The method of claim 7, wherein the visual simulation grading method is implemented by marking the position of symptoms on the horizontal line according to the self-dry condition of the mouth, and then the evaluator measures the length from 0 to the marked point and divides the length by the length of the whole horizontal line to obtain the corresponding ratio as the score of the visual simulation grading method of the patient, wherein the questionnaire is an XQ questionnaire established by the university of Michigan, and scores 8 questions about the dry symptom of the mouth with each question score of 0-10, and the degree of the dry symptom is judged by the score, and the more the dry symptom is scored.

10. The method of claim 1 for magnetic resonance diffusion-weighted imaging-based assessment after transient taste stimulation, wherein in S7, the subjects with obvious change of dynamic DW-MRI examination data after the first transient taste stimulation are selected as fixed follow-up time points in the radiotherapy and 1 month, 6 months, 12 months and 24 months after the radiotherapy, and repeatedly performing dynamic DW-MRI examination after the brief taste stimulation of lemon juice to obtain corresponding ADC value and dynamic curve and comparing with those before radiotherapy, other unselected subjects with gradual change of dynamic DW-MRI examination data after the first transient taste stimulation are treated as fixed follow-up time points in radiotherapy and 1 month, 12 months and 24 months after the radiotherapy, and repeating the check of dynamic DW-MRI after the lemon juice transient taste stimulation to obtain corresponding ADC value and dynamic curve and comparing with those before radiotherapy.

Technical Field

The invention relates to the technical field of radioactive salivary gland injury evaluation, in particular to an evaluation method mainly based on magnetic resonance diffusion weighted imaging after transient taste stimulation.

Background

Nasopharyngeal carcinoma is a common head and neck malignant tumor in China, which seriously harms the health of people, and as a main treatment method of nasopharyngeal carcinoma, radiotherapy plays an important role in reducing local recurrence, controlling distant metastasis and improving the survival rate of patients. On the other hand, however, the primary tumor of the nasopharynx and its lymphatic drainage are in close proximity to the salivary glands, and often the whole or part of the salivary gland tissue is included in the field of irradiation. Therefore, over 80% of nasopharyngeal carcinoma radiotherapy patients suffer from radioactive damage to their salivary glands in different degrees, resulting in a series of acute and chronic symptoms, which seriously affect oral health and nutrition supply, and reduce quality of life (QOL). Among these, dry mouth is one of the most serious symptoms. Therefore, how to early detect and accurately evaluate the radioactive salivary gland injury so as to guide the clinical timely intervention and treatment is very important. DW-MRI can utilize the method of ADC value survey to reflect the functional condition of salivary gland through the water of content in the evaluation histiocyte most, and is more objective than the traditional image method through the form evaluation alone. DW-MRI after taste stimulus can simultaneously evaluate the basic and reserve functions of salivary glands, and is a potential new method for evaluating the salivary gland condition of nasopharyngeal carcinoma patients after radiotherapy. In 2011, professor Kato of medical college of the university of beiyen longyumony leads to the application of dynamic DW-MRI after taste stimulation to the clinic, and a plurality of scholars at home and abroad carry out a series of researches on the evaluation of salivary gland functions after head and neck radiotherapy by adopting similar technologies and obtain positive results, but at present, the problems that a uniform and complete standard evaluation method is still lacked for radioactive salivary gland injury (xerostomia), the existing evaluation method is low in accuracy, the dynamic DW-MRI method after taste stimulation is inconsistent, and the commonly researched vitamin C tablet buccal method is easy to cause measurement errors and the like still exist.

Therefore, we propose an evaluation method based on mri diffusion weighted imaging after transient taste stimulation to solve the above problem.

Disclosure of Invention

The invention aims to solve the problems that the accuracy of the existing evaluation method is low, the dynamic DW-MRI method after taste stimulation is inconsistent, the commonly-used buccal administration method of vitamin C tablets is easy to cause measurement errors and the like, and provides the evaluation method mainly based on magnetic resonance diffusion weighted imaging after transient taste stimulation.

In order to achieve the purpose, the invention adopts the following technical scheme:

an evaluation method based on magnetic resonance diffusion weighted imaging after transient taste stimulation, comprising the following steps:

s1: preparation before taste stimulation DW-MRI examination: selecting subjects and uniformly preparing the selected subjects before the DW-MRI examination of taste stimulation;

s2: the lemon juice transient taste stimulation method is adopted: injecting lemon juice into the mouth of a subject, keeping for 10s, and then swallowing;

s3: dynamic DW-MRI examination technique after transient gustatory stimulation: carrying out examination after transient taste stimulation on the selected experimental object by adopting an MRI technology;

s4: DW-MRI post-treatment method: processing the DW-MRI original image through software, and drawing a data change curve;

s5: measurement of saliva flow rate: acquiring flow rate and other saliva data of saliva at different times through calculation;

s6: evaluation mechanism: the salivary gland function and the xerostomia of the patient are evaluated more comprehensively and individually by adopting a salivary flow rate measurement and a grading and scoring method for various xerostomia;

s7, periodic detection and repeated evaluation: stimulating again at an interval time period after the first brief gustatory stimulation, evaluating again, and comparing the evaluation results;

preferably, in S1, the subjects of different sexes and ages with nasopharyngeal carcinoma are selected to be treated with radiation by the same technique in the same time period, and the treated subjects are prepared before being treated with taste stimulation DW-MRI examination, wherein all examinations are performed in the same time period every day, and water is prohibited 1 hour before each scan;

preferably, in the S2, 5ml of 100% lemon juice after shaking and mixing is injected into the mouth of the subject, wherein the lemon juice selected by the invention is lemnodor of Baylang Gi corporation, Italy, and is swallowed clean after 10S is kept, and the subject is not fed with water after swallowing before performing dynamic DW-MRI examination after transient taste stimulation;

preferably, in S3, a 16-channel head and neck combined phased array coil is used, and all patients are in the anterior and posterior parotid gland, submandibular gland and tongue of IMRTPerforming DW-MRI examination on lower gland in supine position in scanning range including parotid gland, submandibular gland and sublingual gland, wherein DW-MRI adopts EPI sequence, scanning parameters are TR4000ms, TE55ms, FOV180mm, matrix 256 × 512, excitation times are 1 time, layer thickness is 6mm, interval is 1mm, scanning layers are 18 layers, and b value is 0 and 1000s/mm²Before and after radiotherapy, scanning parameters are required to be kept consistent, DW-MRI scanning of 1 time of parotid gland, submandibular gland and sublingual gland is firstly carried out in a resting state (before taste stimulation) for each inspection, and MRDWI scanning of three salivary gland rows is carried out for 10 times after taste stimulation, wherein the starting time of dynamic scanning is 30s after stimulation starts, the scanning time of single MRDWI scanning is 1min30s, and the interval is 30 s;

preferably, in S4, the DW-MRI raw image is processed by using ExtendedMRWorkSpace software of Philips, wherein the outline of the bilateral parotid gland, the submandibular gland and the sublingual gland is sketched on each image by using the ROI method, including all gland parenchyma, and avoiding the great vessels and ducts, the SI (signal intensity) of each salivary gland on each image is measured, the SI of each glandular layer is averaged, and the measured SI is substituted into a formula to obtain the resting and post-stimulation ADC value, where the formula is: ADC ═ ln (SI)₁/SI₂)]/(b₂-b₁) Wherein b is₁And b₂For corresponding b value, SI₁And SI₂Respectively, the signal intensity at the time of the b value is taken, the maximum ADC value increase rate after stimulation is (maximum ADC value after stimulation-ADC value before stimulation)/ADC value before stimulation, Tmax (ADC peak time) is the time from the start of taste stimulation to the maximum ADC value after stimulation, the ADC value of each glandular body on one side, the maximum ADC value IR after stimulation and Tmax are calculated, the average values are taken on two sides, drawing an ADC value-time change curve according to the ADC value of each salivary gland at each time point before and after stimulation, wherein the peak value corresponds to Tmax and the maximum ADC value after stimulation, respectively recording the average resting ADC value, the maximum ADC value after stimulation, the maximum ADC value IR and Tmax after stimulation of each gland before and after radiotherapy, calculating the difference rate of the resting ADC value and the maximum ADC value after stimulation of each gland before and after radiotherapy, wherein the difference rate between the resting ADC value of each gland and the maximum ADC value after stimulation before and after radiotherapy is calculated by the following formula: rADC_{Salivary gland}(％)＝(ADC_{After radiotherapy}–ADC_{RadiotherapyFront side})/ADC_{Before radiotherapy}；

Preferably, in S5, the flow rate of saliva at different times and other saliva data are obtained by calculation, wherein the resting saliva flow rate is calculated by a lap method, the lap method is that a lap with the size of 1.0cm × 1.2cm is weighed in advance, then placed at the opening of each salivary gland in the mouth, collected for 5min and then weighed again, the mixed saliva amount of the left and right parotid glands and the sublingual salivary gland at the resting time and the sublingual salivary fluid amount are respectively measured, the whole salivary fluid amount is obtained by adding the two, the saliva flow rate after stimulation is calculated by a lemon juice stimulation method, and the lap method is simultaneously used for calculation, the unit of the saliva flow rate after resting and stimulation is calculated as g/min, and the saliva flow rate change (%) is calculated as the resting saliva flow rate after saliva stimulation-saliva flow rate resting/saliva flow rate, and the saliva flow rate after stimulation before and after radiotherapy, and after the saliva flow rate after stimulation are recorded, the formula for calculating the difference rate of the resting salivary flow rate of parotid gland, sublingual jaw gland and whole gland and the stimulated salivary flow rate before and after radiotherapy is as follows: saliva flow rate difference (%) (saliva flow rate)_{After radiotherapy}Salivary flow Rate_{Before radiotherapy}) Flow Rate of saliva_{Before radiotherapy}；

Preferably, in S6, the salivary gland function and the xerostomia of the patient are evaluated more comprehensively and individually by using a salivary flow rate measurement and a grading and scoring method for xerostomia, wherein the grading and scoring method for xerostomia comprises a grading standard of tumor therapy toxicity xerostomia, a visual simulation grading method and a questionnaire, wherein the grading standard of tumor therapy toxicity xerostomia is graded by a static salivary flow rate value, no obvious change of eating habits is generated, the static salivary flow rate is more than 0.2ml/min, mild xerostomia is determined by the grading standard, the moderate xerostomia is determined by the obvious change of eating habits (half-stream or liquid diet) and the static salivary flow rate is 0.1-0.2ml/min, oral cavity feeding is not performed, nasal feeding or intravenous nutrition is required, and the static salivary flow rate is less than 0.1ml/min, the visual simulation grading method is performed by the patient according to the self-xerostomia, marking the position of symptoms on a horizontal line, measuring the length from 0 point to a marked point by an evaluator, dividing the length by the length of the whole horizontal line to obtain a corresponding ratio as a score of a visual simulation grading method of a patient, wherein the questionnaire is an XQ Questionnaire (XQ) established by the university of Michigan, 8 questions related to the symptoms of the dry mouth are scored, each question is scored to be 0-10 points, and the degree of the symptoms of the dry mouth is judged by the score, and the heavier the symptoms of the dry mouth is, the higher the score is;

preferably, in S7, the subject with significant change in the dynamic DW-MRI data after the first brief taste stimulus is selected as a fixed follow-up time point during the radiotherapy and after 1 month, 6 months, 12 months, and 24 months after the radiotherapy, and the dynamic DW-MRI check after the brief taste stimulus of lemon juice is repeated, and corresponding ADC values and dynamic curves are obtained and compared with the values before the radiotherapy, and the other unselected subjects with gradual change in the dynamic DW-MRI data after the first brief taste stimulus are selected as fixed follow-up time points during the radiotherapy and after 1 month, 12 months, and 24 months after the radiotherapy, and the dynamic DW-MRI check after the brief taste stimulus of lemon juice is repeated, and corresponding ADC values and dynamic curves are obtained and compared with the values before the radiotherapy.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention adopts a standardized preparation method before examination, and the pioneer unit and part of research reports do not provide relevant information.

2. The invention properly shortens the stimulation time, improves the tolerance of patients and the technical feasibility, adopts a vitamin C tablet oral administration method in other reports, and has long stimulation time, large individual difference and poor research comparability and repeatability.

3. The invention uses the shortest single DW-MRI scanning time and the largest number of dynamic scanning in all researches, and ensures the change trend after taste stimulation as complete as possible while reducing artifacts.

4. The maximum imaging matrix and the smallest visual field possible are adopted, and the image quality is improved.

5. Only the technology evaluates all salivary glands (including parotid gland, submandibular gland and sublingual gland) on two sides, and uses the most DW-MRI evaluation analysis indexes, so that the evaluation of the salivary gland function is more accurate.

6. The unit and the initial unit measure the saliva flow rate of the patient, but the technology adopts a cotton roll method for separately measuring parotid saliva and sublingual palatine gland saliva and simultaneously measuring the resting saliva and the stimulated saliva, is superior to a Saxon test which is used for measuring all saliva and only measuring the stimulated saliva and is more accurate in evaluation of different glands. None of the other reports measured salivary flow rate.

The invention aims to adopt the lemon juice transient taste stimulus as a stimulation method, avoid measurement errors caused by individual dissolution difference of vitamin C tablets, more stably reflect the dynamic change trend of ADC values of various salivary glands after taste stimulus, contribute to comparability and repeatability of future research, shorten the retention time of lemon juice in the mouth and reduce artifacts caused by swallowing action due to excessive saliva.

Drawings

FIG. 1 is a flow chart of a magnetic resonance diffusion weighted imaging-based evaluation method after transient taste stimulation according to the present invention;

FIG. 2 is a dynamic DWMRI image of the left parotid gland of a magnetic resonance diffusion-weighted imaging-based assessment method of the present invention proposed for post-transient taste stimulation;

fig. 3 is a drawing of a right parotid gland DW-MRI image region-of-interest plot a and a right parotid gland ADC value-time dynamic change curve b of the evaluation method based on magnetic resonance diffusion weighted imaging after transient taste stimulation.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Example one

Referring to fig. 1-3, a magnetic resonance diffusion weighted imaging-based evaluation method after transient taste stimulation, comprising the steps of:

s1: preparation before taste stimulation DW-MRI examination: selecting subjects with nasopharyngeal carcinoma of different sexes and ages, performing radiotherapy in the same time period by using the same technology, and uniformly performing preparation before taste stimulation DW-MRI examination on the subjects after the radiotherapy, wherein all examinations are performed in the same time period every day, and water is forbidden 1 hour before each scan;

s2: the lemon juice transient taste stimulation method is adopted: injecting 5ml of 100% lemon juice which is uniformly mixed by shaking into the mouth of a subject, wherein the lemon juice selected by the invention is lemnodor of Baylang Gi, Italy, keeping for 10s, then swallowing cleanly, and after swallowing, the subject forbids drinking water before dynamic DW-MRI examination after transient taste stimulation;

s3: dynamic DW-MRI examination technique after transient gustatory stimulation: adopting MRI technology to carry out examination after transient taste stimulation on selected experimental objects, wherein 16-channel head-neck combined phased array control coils are adopted, all patients are subjected to DW-MRI examination on anterior parotid gland, posterior parotid gland, submandibular gland and sublingual gland before IMRT, the supine position is adopted during scanning, the scanning range comprises two parotid glands, submandibular glands and sublingual glands, the DW-MRI adopts an EPI sequence, the scanning parameters are TR4000ms, TE55ms, FOV180mm, a matrix 256 multiplied by 512, the excitation times are 1 time, the layer thickness is 6mm, the interval is 1mm, the number of scanning layers is 18, and the b value is 0 and 1000s/mm²Before and after radiotherapy, scanning parameters are required to be kept consistent, DW-MRI scanning of 1 time of parotid gland, submaxillary gland and sublingual gland is firstly carried out in a resting state (before taste stimulation) for each inspection, and MR DWI scanning of three salivary gland rows is carried out for 10 times after taste stimulation is carried out, wherein the starting time of dynamic scanning is 30s after stimulation is started, the scanning time of single MR DWI scanning is 1min30s, and the interval is 30 s;

s4: DW-MRI post-treatment method: processing DW-MRI original images by adopting Extended MR word Space software of Philips company, wherein outlines of bilateral parotid gland, submandibular gland and sublingual gland are sketched on each image by adopting an ROI method, including all gland parenchyma, the outline is avoided from great vessels and ducts, SI (signal intensity) of each salivary gland on each layer of image is measured, the SI of each layer of gland is averaged, and the measured SI is substituted into a formula to obtain an ADC value after resting and stimulation, wherein the formula is as follows: ADC ═ ln (SI)₁/SI₂)]/(b₂-b₁) Wherein b is₁And b₂For corresponding b value, SI₁And SI₂Are respectively taken upThe signal intensity at the value b, the maximum increase rate of the post-stimulation ADC value ═ maximum ADC value after stimulation-ADC value before stimulation)/ADC value before stimulation, Tmax (ADC peak time) is the time from the start of taste stimulation to the maximum ADC value after stimulation, the ADC value of each gland on one side, maximum ADC value IR after stimulation and Tmax are calculated, the average values are taken on both sides, an ADC value-time variation curve is drawn according to the ADC values of each salivary gland at each time point before and after stimulation, and the peak values correspond to Tmax and the maximum ADC value after stimulation, and the average resting ADC value before and after radiotherapy, the maximum ADC value after stimulation and the maximum ADC value after stimulation are respectively recorded, and the difference rate of the resting ADC value of each gland and the maximum ADC value after stimulation before and after radiotherapy is calculated, wherein the calculation formula of the difference rate of the resting ADC value of each gland and the maximum ADC value after stimulation before and after radiotherapy is: rADC_{Salivary gland}(％)＝(ADC_{After radiotherapy}–ADC_{Before radiotherapy})/ADC_{Before radiotherapy}；

S5: measurement of saliva flow rate: obtaining flow rate of saliva at different time and other saliva data by calculation, wherein the resting saliva flow rate is calculated by a lap method, the lap method is to weigh a lap with the size of 1.0cm multiplied by 1.2cm in advance, place the lap at the opening of each salivary gland in the mouth, collect the lap for 5min, weigh again, respectively measure the mixed saliva amount of the parotid saliva amount and the sublingual salivary gland at the resting time, add the two to obtain the whole gland saliva amount, the saliva flow rate after stimulation is calculated by a lemon juice stimulation method, the lap method is used for calculation, the unit of the saliva flow rate after resting and stimulation is calculated as g/min, the saliva flow rate change rate is (after saliva flow rate stimulation-saliva flow rate resting/saliva flow rate resting), and the resting saliva flow rate before and after radiotherapy of parotid sublingual salivary gland and whole gland, the saliva flow rate after stimulation and saliva change rate after stimulation are recorded, the formula for calculating the difference rate of the resting salivary flow rate of parotid gland, sublingual jaw gland and whole gland and the stimulated salivary flow rate before and after radiotherapy is as follows: saliva flow rate difference (%) (saliva flow rate)_{After radiotherapy}Salivary flow Rate_{Before radiotherapy}) Flow Rate of saliva_{Before radiotherapy}；

S6: evaluation mechanism: the salivary gland function and the xerostomia of the patient are evaluated more comprehensively and individually by adopting a salivary flow rate measurement and a grading and grading method of the xerostomia, wherein the grading and grading method of the xerostomia comprises a grading standard of tumor treatment toxicity xerostomia, a visual simulation grading method and a questionnaire, wherein the grading standard of the tumor treatment toxicity xerostomia is graded by a static salivary flow rate value, mild xerostomia is judged by no obvious change of eating habits and the static salivary flow rate is more than 0.2ml/min, moderate xerostomia is judged by obvious change of eating habits (half-flow or diet) and the static salivary flow rate is 0.1-0.2ml/min, oral cavity feeding is not realized, nasal feeding tube or vein nutrition is needed, and the severe xerostomia is judged by the static salivary flow rate is less than 0.1ml/min, the visual simulation grading method is that the symptom position of the patient is marked on a transverse line according to the self xerostomia condition, then, the evaluator measures the length from 0 point to the mark point and divides the length of the whole transverse line to obtain a corresponding ratio as the score of the visual simulation grading method of the patient, wherein the questionnaire is an XQ Questionnaire (XQ) established by the university of Michigan in America, 8 questions related to the symptoms of the dry mouth are scored, each question is scored to be 0-10, the degree of the symptoms of the dry mouth is judged by the score, and the more serious the symptoms of the dry mouth is, the higher the score is;

s7, periodic detection and repeated evaluation: selecting subjects with obvious change of dynamic DW-MRI examination data after the first transient taste stimulus as fixed follow-up time points in radiotherapy and after 1 month, 6 months, 12 months and 24 months after the radiotherapy, repeatedly carrying out the dynamic DW-MRI examination after the transient taste stimulus of lemon juice, obtaining corresponding ADC values and dynamic curves and comparing the ADC values and the dynamic curves with the fixed follow-up time points before the radiotherapy, taking other unselected subjects with slow change of the dynamic DW-MRI examination data after the first transient taste stimulus as fixed follow-up time points in the radiotherapy and after 1 month, 12 months and 24 months after the radiotherapy, repeatedly carrying out the dynamic DW-MRI examination after the transient taste stimulus of lemon juice, obtaining corresponding ADC values and dynamic curves and comparing the ADC values and the dynamic curves with the fixed follow-up time points before the radiotherapy.

Example two

Referring to fig. 1-3, a magnetic resonance diffusion weighted imaging-based evaluation method after transient taste stimulation, comprising the steps of:

s1: preparation before taste stimulation DW-MRI examination: selecting subjects of different sexes and ages and suffering from nasopharyngeal carcinoma to perform radiotherapy in the same time period by using the same technology;

s2: the lemon juice transient taste stimulation method is adopted: injecting 5ml of 100% lemon juice which is uniformly mixed by shaking into the mouth of a subject, wherein the lemon juice selected by the invention is lemnodor of Baylang Gi, Italy, keeping for 10s, then swallowing cleanly, and after swallowing, the subject forbids drinking water before dynamic DW-MRI examination after transient taste stimulation;

s3: dynamic DW-MRI examination technique after transient gustatory stimulation: adopting MRI technology to carry out examination after transient taste stimulation on a selected experimental object, wherein a 16-channel head-neck combined phased array control coil is adopted, all patients are subjected to DW-MRI examination on anterior and posterior parotid glands, submandibular glands and sublingual glands before and after IMRT, the supine position is adopted during scanning, the scanning range comprises two lateral parotid glands, submandibular glands and sublingual glands, the DW-MRI adopts an EPI sequence, the scanning parameters are TR4000ms, TE55ms, FOV180mm, a matrix 256 multiplied by 512, the excitation times are 1 time, the layer thickness is 6mm, the interval is 1mm, the number of scanning layers is 18, and the b value is 0 and 1000s/mm²Before and after radiotherapy, scanning parameters are required to be kept consistent, DW-MRI scanning of 1 time of parotid gland, submaxillary gland and sublingual gland is firstly carried out in a resting state (before taste stimulation) for each inspection, and MR DWI scanning of three salivary gland rows is carried out for 10 times after taste stimulation is carried out, wherein the starting time of dynamic scanning is 30s after stimulation is started, the scanning time of single MR DWI scanning is 1min30s, and the interval is 30 s;

s4: DW-MRI post-treatment method: processing DW-MRI original images by adopting Extended MR word Space software of Philips company, wherein outlines of bilateral parotid gland, submandibular gland and sublingual gland are sketched on each image by adopting an ROI method, including all gland parenchyma, the outline is avoided from great vessels and ducts, SI (signal intensity) of each salivary gland on each layer of image is measured, the SI of each layer of gland is averaged, and the measured SI is substituted into a formula to obtain an ADC value after resting and stimulation, wherein the formula is as follows: ADC ═ ln (SI)₁/SI₂)]/(b₂-b₁) Wherein b is₁And b₂For corresponding b value, SI₁And SI₂The signal intensity at the time of the b value and the maximum ADC increase rate after stimulation were taken (stimulation)The method comprises the following steps of calculating the average value of two sides, drawing an ADC value-time change curve according to the ADC value of each salivary gland at each time point before and after stimulation, wherein the peak value corresponds to Tmax and the maximum ADC value after stimulation, respectively recording the average resting ADC value before and after radiotherapy, the maximum ADC value after stimulation and the maximum ADC value after stimulation, and calculating the difference rate of the resting ADC value of each gland and the maximum ADC value after stimulation before and after radiotherapy, wherein the calculation formula of the difference rate of the resting ADC value of each gland and the maximum ADC value after stimulation before and after radiotherapy is as follows: rADC_{Salivary gland}(％)＝(ADC_{After radiotherapy}–ADC_{Before radiotherapy})/ADC_{Before radiotherapy}；

S5: measurement of saliva flow rate: obtaining flow rate of saliva at different time and other saliva data by calculation, wherein the resting saliva flow rate is calculated by a lap method, the lap method is to weigh a lap with the size of 1.0cm multiplied by 1.2cm in advance, place the lap at the opening of each salivary gland in the mouth, collect the lap for 5min, weigh again, respectively measure the mixed saliva amount of the parotid saliva amount and the sublingual salivary gland at the resting time, add the two to obtain the whole gland saliva amount, the saliva flow rate after stimulation is calculated by a lemon juice stimulation method, the lap method is used for calculation, the unit of the saliva flow rate after resting and stimulation is calculated as g/min, the saliva flow rate change rate is (after saliva flow rate stimulation-saliva flow rate resting/saliva flow rate resting), and the resting saliva flow rate before and after radiotherapy of parotid sublingual salivary gland and whole gland, the saliva flow rate after stimulation and saliva change rate after stimulation are recorded, the formula for calculating the difference rate of the resting salivary flow rate of parotid gland, sublingual jaw gland and whole gland and the stimulated salivary flow rate before and after radiotherapy is as follows: saliva flow rate difference (%) (saliva flow rate)_{After radiotherapy}Salivary flow Rate_{Before radiotherapy}) Flow Rate of saliva_{Before radiotherapy}；

S6: evaluation mechanism: the salivary gland function and the xerostomia of the patient are evaluated more comprehensively and individually by adopting a salivary flow rate measurement and a grading and grading method of the xerostomia, wherein the grading and grading method of the xerostomia comprises a grading standard of tumor treatment toxicity xerostomia, a visual simulation grading method and a questionnaire, wherein the grading standard of the tumor treatment toxicity xerostomia is graded by a static salivary flow rate value, mild xerostomia is judged by no obvious change of eating habits and the static salivary flow rate is more than 0.2ml/min, moderate xerostomia is judged by obvious change of eating habits (half-flow or diet) and the static salivary flow rate is 0.1-0.2ml/min, oral cavity feeding is not realized, nasal feeding tube or vein nutrition is needed, and the severe xerostomia is judged by the static salivary flow rate is less than 0.1ml/min, the visual simulation grading method is that the symptom position of the patient is marked on a transverse line according to the self xerostomia condition, then, the evaluator measures the length from 0 point to the mark point and divides the length of the whole transverse line to obtain a corresponding ratio as the score of the visual simulation grading method of the patient, wherein the questionnaire is an XQ Questionnaire (XQ) established by the university of Michigan in America, 8 questions related to the symptoms of the dry mouth are scored, each question is scored to be 0-10, the degree of the symptoms of the dry mouth is judged by the score, and the more serious the symptoms of the dry mouth is, the higher the score is;

s7, periodic detection and repeated evaluation: selecting subjects with obvious change of dynamic DW-MRI examination data after the first transient taste stimulus as fixed follow-up time points in radiotherapy and after 1 month, 6 months, 12 months and 24 months after the radiotherapy, repeatedly carrying out the dynamic DW-MRI examination after the transient taste stimulus of lemon juice, obtaining corresponding ADC values and dynamic curves and comparing the ADC values and the dynamic curves with the fixed follow-up time points before the radiotherapy, taking other unselected subjects with slow change of the dynamic DW-MRI examination data after the first transient taste stimulus as fixed follow-up time points in the radiotherapy and after 1 month, 12 months and 24 months after the radiotherapy, repeatedly carrying out the dynamic DW-MRI examination after the transient taste stimulus of lemon juice, obtaining corresponding ADC values and dynamic curves and comparing the ADC values and the dynamic curves with the fixed follow-up time points before the radiotherapy.

EXAMPLE III

Referring to fig. 1-3, a magnetic resonance diffusion weighted imaging-based evaluation method after transient taste stimulation, comprising the steps of:

s1: preparation before taste stimulation DW-MRI examination: selecting subjects with nasopharyngeal carcinoma of different sexes and ages, performing radiotherapy in the same time period by using the same technology, and uniformly performing preparation before taste stimulation DW-MRI examination on the subjects after the radiotherapy, wherein all examinations are performed in the same time period every day, and water is forbidden 1 hour before each scan;

s2: the lemon juice transient taste stimulation method is adopted: injecting 5ml of 100% lemon juice which is uniformly mixed by shaking into the mouth of a subject, wherein the lemon juice selected by the invention is lemnodor of Baylang Gi, Italy, keeping for 10s, then swallowing cleanly, and after swallowing, the subject forbids drinking water before dynamic DW-MRI examination after transient taste stimulation;

s3: dynamic DW-MRI examination technique after transient gustatory stimulation: adopting MRI technology to carry out examination after transient taste stimulation on selected experimental objects, wherein 16-channel head-neck combined phased array control coils are adopted, all patients are subjected to DW-MRI examination on anterior parotid gland, posterior parotid gland, submandibular gland and sublingual gland before IMRT, the supine position is adopted during scanning, the scanning range comprises two parotid glands, submandibular glands and sublingual glands, the DW-MRI adopts an EPI sequence, the scanning parameters are TR4000ms, TE55ms, FOV180mm, a matrix 256 multiplied by 512, the excitation times are 1 time, the layer thickness is 6mm, the interval is 1mm, the number of scanning layers is 18, and the b value is 0 and 1000s/mm²Before and after radiotherapy, scanning parameters are required to be kept consistent, DW-MRI scanning of 1 time of parotid gland, submandibular gland and sublingual gland is firstly carried out in a resting state (before taste stimulation) for each inspection, and MRDWI scanning of three salivary gland rows is carried out for 10 times after taste stimulation, wherein the starting time of dynamic scanning is 30s after stimulation starts, the scanning time of single MR DWI is 1min30s, and the interval is 30 s;

s4: DW-MRI post-treatment method: processing DW-MRI original images by adopting Extended MR word Space software of Philips company, wherein outlines of bilateral parotid gland, submandibular gland and sublingual gland are sketched on each image by adopting an ROI method, including all gland parenchyma, the outline is avoided from great vessels and ducts, SI (signal intensity) of each salivary gland on each layer of image is measured, the SI of each layer of gland is averaged, and the measured SI is substituted into a formula to obtain an ADC value after resting and stimulation, wherein the formula is as follows: ADC ═ ln (SI)₁/SI₂)]/(b₂-b₁) Wherein b is₁And b₂For corresponding b value, SI₁And SI₂Respectively, the signal intensity at the time of the b value is taken, the maximum ADC value increase rate after stimulation is (maximum ADC value after stimulation-ADC value before stimulation)/ADC value before stimulation, Tmax (ADC peak time) is the time from the start of taste stimulation to the maximum ADC value after stimulation, the ADC value of each glandular body on one side, the maximum ADC value IR after stimulation and Tmax are calculated, the average values are taken on two sides, drawing an ADC value-time change curve according to the ADC value of each salivary gland at each time point before and after stimulation, wherein the peak value corresponds to Tmax and the maximum ADC value after stimulation, respectively recording the average resting ADC value, the maximum ADC value after stimulation, the maximum ADC value IR and Tmax after stimulation of each gland before and after radiotherapy, calculating the difference rate of the resting ADC value and the maximum ADC value after stimulation of each gland before and after radiotherapy, wherein the difference rate between the resting ADC value of each gland and the maximum ADC value after stimulation before and after radiotherapy is calculated by the following formula: rADC_{Salivary gland}(％)＝(ADC_{After radiotherapy}–ADC_{Before radiotherapy})/ADC_{Before radiotherapy}；

S5: measurement of saliva flow rate: obtaining flow rate of saliva at different time and other saliva data by calculation, wherein the resting saliva flow rate is calculated by a lap method, the lap method is to weigh a lap with the size of 1.0cm multiplied by 1.2cm in advance, place the lap at the opening of each salivary gland in the mouth, collect the lap for 5min, weigh again, respectively measure the mixed saliva amount of the parotid saliva amount and the sublingual salivary gland at the resting time, add the two to obtain the whole gland saliva amount, the saliva flow rate after stimulation is calculated by a lemon juice stimulation method, the lap method is used for calculation, the unit of the saliva flow rate after resting and stimulation is calculated as g/min, the saliva flow rate change rate is (after saliva flow rate stimulation-saliva flow rate resting/saliva flow rate resting), and the resting saliva flow rate before and after radiotherapy of parotid sublingual salivary gland and whole gland, the saliva flow rate after stimulation and saliva change rate after stimulation are recorded, the formula for calculating the difference rate of the resting salivary flow rate of parotid gland, sublingual jaw gland and whole gland and the stimulated salivary flow rate before and after radiotherapy is as follows: saliva flow rate difference (%) (saliva flow rate)_{After radiotherapy}Salivary flow Rate_{Before radiotherapy}) Flow Rate of saliva_{Before radiotherapy}；

S6: evaluation mechanism: the salivary gland function and the xerostomia of the patient are evaluated more comprehensively and individually by adopting a salivary flow rate measurement and xerostomia grading and scoring method, wherein the xerostomia grading and scoring method comprises a tumor treatment toxic xerostomia grading standard, the tumor treatment toxic xerostomia grading standard is graded through a static salivary flow rate value, mild xerostomia is judged when no obvious dietary habit changes and the static salivary flow rate is more than 0.2ml/min, moderate xerostomia is judged when the obvious dietary habit changes (half-flow or diet) and the static salivary flow rate is 0.1-0.2ml/min, oral cavity feeding is not realized, nasal feeding tube or venous nutrition is required, and the static salivary flow rate is less than 0.1ml/min, and severe xerostomia is judged;

s7, periodic detection and repeated evaluation: selecting subjects with obvious change of dynamic DW-MRI examination data after the first transient taste stimulus as fixed follow-up time points in radiotherapy and after 1 month, 6 months, 12 months and 24 months after the radiotherapy, repeatedly carrying out the dynamic DW-MRI examination after the transient taste stimulus of lemon juice, obtaining corresponding ADC values and dynamic curves and comparing the ADC values and the dynamic curves with the fixed follow-up time points before the radiotherapy, taking other unselected subjects with slow change of the dynamic DW-MRI examination data after the first transient taste stimulus as fixed follow-up time points in the radiotherapy and after 1 month, 12 months and 24 months after the radiotherapy, repeatedly carrying out the dynamic DW-MRI examination after the transient taste stimulus of lemon juice, obtaining corresponding ADC values and dynamic curves and comparing the ADC values and the dynamic curves with the fixed follow-up time points before the radiotherapy.

Example four

Referring to fig. 1-3, a magnetic resonance diffusion weighted imaging-based evaluation method after transient taste stimulation, comprising the steps of:

s1: preparation before taste stimulation DW-MRI examination: selecting subjects with nasopharyngeal carcinoma of different sexes and ages, performing radiotherapy in the same time period by using the same technology, and uniformly performing preparation before taste stimulation DW-MRI examination on the subjects after the radiotherapy, wherein all examinations are performed in the same time period every day, and water is forbidden 1 hour before each scan;

s2: the lemon juice transient taste stimulation method is adopted: injecting 5ml of 100% lemon juice which is uniformly mixed by shaking into the mouth of a subject, wherein the lemon juice selected by the invention is lemnodor of Baylang Gi, Italy, keeping for 10s, then swallowing cleanly, and after swallowing, the subject forbids drinking water before dynamic DW-MRI examination after transient taste stimulation;

s3: dynamic DW-MRI examination technique after transient gustatory stimulation: adopting MRI technology to carry out examination after transient taste stimulation on a selected experimental object, wherein a 16-channel head-neck combined phased array control coil is adopted, all patients are subjected to DW-MRI examination on anterior and posterior parotid glands, submandibular glands and sublingual glands before and after IMRT, the supine position is adopted during scanning, the scanning range comprises two lateral parotid glands, submandibular glands and sublingual glands, the DW-MRI adopts an EPI sequence, the scanning parameters are TR4000ms, TE55ms, FOV180mm, a matrix 256 multiplied by 512, the excitation times are 1 time, the layer thickness is 6mm, the interval is 1mm, the number of scanning layers is 18, and the b value is 0 and 1000s/mm²Before and after radiotherapy, scanning parameters are required to be kept consistent, DW-MRI scanning of 1 time of parotid gland, submaxillary gland and sublingual gland is firstly carried out in a resting state (before taste stimulation) for each inspection, and MR DWI scanning of three salivary gland rows is carried out for 10 times after taste stimulation is carried out, wherein the starting time of dynamic scanning is 30s after stimulation is started, the scanning time of single MR DWI scanning is 1min30s, and the interval is 30 s;

s4: DW-MRI post-treatment method: processing DW-MRI original images by adopting Extended MR word Space software of Philips company, wherein outlines of bilateral parotid gland, submandibular gland and sublingual gland are sketched on each image by adopting an ROI method, including all gland parenchyma, the outline is avoided from great vessels and ducts, SI (signal intensity) of each salivary gland on each layer of image is measured, the SI of each layer of gland is averaged, and the measured SI is substituted into a formula to obtain an ADC value after resting and stimulation, wherein the formula is as follows: ADC ═ ln (SI)₁/SI₂)]/(b₂-b₁) Wherein b is₁And b₂For corresponding b value, SI₁And SI₂Respectively taking the signal intensity when the value b is obtained, calculating the ADC value of each gland on one side, the maximum ADC value IR after stimulation and Tmax after stimulation, and averaging the two sides, wherein the maximum ADC value increase rate after stimulation is (the maximum ADC value after stimulation-the ADC value before stimulation)/the ADC value before stimulation, and the Tmax (the ADC peak time) is the time from the start of taste stimulation to the maximum ADC value after stimulation;

s5: measurement of saliva flow rate: the flow rate of the saliva at different times and other saliva data are obtained by calculation, wherein the resting saliva flow rate is calculated by a cotton roll method, the lap method comprises weighing lap of 1.0cm × 1.2cm in size in advance, placing at the opening of each salivary gland in mouth, collecting for 5min, weighing again, respectively measuring the mixed saliva volume of parotid fluid and submaxillary hypoglossal gland at rest, adding the above two to obtain total salivary fluid volume, calculating stimulated salivary flow rate by lemon juice stimulation method, meanwhile, a cotton roll method is adopted for calculation, the unit of the saliva flow rate after the rest and stimulation is calculated as g/min, and the saliva flow rate change rate (%) is equal to (the saliva flow rate after the stimulation-the saliva flow rate rest)/the saliva flow rate rest, recording resting saliva flow rate, stimulated saliva flow rate and stimulated saliva flow rate change rate of parotid gland, sublingual jaw gland and whole gland before and after radiotherapy;

s6: evaluation mechanism: the salivary gland function and the xerostomia of the patient are evaluated more comprehensively and individually by adopting a salivary flow rate measurement and a grading and grading method of the xerostomia, wherein the grading and grading method of the xerostomia comprises a grading standard of tumor treatment toxicity xerostomia, a visual simulation grading method and a questionnaire, wherein the grading standard of the tumor treatment toxicity xerostomia is graded by a static salivary flow rate value, mild xerostomia is judged by no obvious change of eating habits and the static salivary flow rate is more than 0.2ml/min, moderate xerostomia is judged by obvious change of eating habits (half-flow or diet) and the static salivary flow rate is 0.1-0.2ml/min, oral cavity feeding is not realized, nasal feeding tube or vein nutrition is needed, and the severe xerostomia is judged by the static salivary flow rate is less than 0.1ml/min, the visual simulation grading method is that the symptom position of the patient is marked on a transverse line according to the self xerostomia condition, then, the evaluator measures the length from 0 point to the mark point and divides the length of the whole transverse line to obtain a corresponding ratio as the score of the visual simulation grading method of the patient, wherein the questionnaire is an XQ Questionnaire (XQ) established by the university of Michigan in America, 8 questions related to the symptoms of the dry mouth are scored, each question is scored to be 0-10, the degree of the symptoms of the dry mouth is judged by the score, and the more serious the symptoms of the dry mouth is, the higher the score is;

s7, periodic detection and repeated evaluation: selecting subjects with obvious change of dynamic DW-MRI examination data after the first transient taste stimulus as fixed follow-up time points in radiotherapy and after 1 month, 6 months, 12 months and 24 months after the radiotherapy, repeatedly carrying out the dynamic DW-MRI examination after the transient taste stimulus of lemon juice, obtaining corresponding ADC values and dynamic curves and comparing the ADC values and the dynamic curves with the fixed follow-up time points before the radiotherapy, taking other unselected subjects with slow change of the dynamic DW-MRI examination data after the first transient taste stimulus as fixed follow-up time points in the radiotherapy and after 1 month, 12 months and 24 months after the radiotherapy, repeatedly carrying out the dynamic DW-MRI examination after the transient taste stimulus of lemon juice, obtaining corresponding ADC values and dynamic curves and comparing the ADC values and the dynamic curves with the fixed follow-up time points before the radiotherapy.

EXAMPLE five

Referring to fig. 1-3, a magnetic resonance diffusion weighted imaging-based evaluation method after transient taste stimulation, comprising the steps of:

s1: preparation before taste stimulation DW-MRI examination: selecting subjects with nasopharyngeal carcinoma of different sexes and ages, performing radiotherapy in the same time period by using the same technology, and uniformly performing preparation before taste stimulation DW-MRI examination on the subjects after the radiotherapy, wherein all examinations are performed in the same time period every day, and water is forbidden 1 hour before each scan;

s2: the lemon juice transient taste stimulation method is adopted: injecting 5ml of 100% lemon juice which is uniformly mixed by shaking into the mouth of a subject, wherein the lemon juice selected by the invention is lemnodor of Baylang Gi, Italy, keeping for 10s, then swallowing cleanly, and after swallowing, the subject forbids drinking water before dynamic DW-MRI examination after transient taste stimulation;

s3: dynamic DW-MRI examination technique after transient gustatory stimulation: adopting MRI technology to carry out examination after transient taste stimulation on a selected experimental object, wherein a 16-channel head-neck combined phased array control coil is adopted, all patients are subjected to DW-MRI examination on anterior and posterior parotid glands, submandibular glands and sublingual glands before and after IMRT, the supine position is adopted during scanning, the scanning range comprises two lateral parotid glands, submandibular glands and sublingual glands, the DW-MRI adopts an EPI sequence, the scanning parameters are TR4000ms, TE55ms, FOV180mm, a matrix 256 multiplied by 512, the excitation times are 1 time, the layer thickness is 6mm, the interval is 1mm, the number of scanning layers is 18, and the b value is 0 and 1000s/mm²And scan the ginseng before and after radiotherapyThe number of the test samples needs to be kept consistent, 1 DW-MRI scan of parotid gland, submaxillary gland and sublingual gland is firstly carried out under a resting state (before taste stimulation) for each test sample, and MR DWI scan of three salivary gland rows is carried out for 10 times after taste stimulation, wherein the starting time of dynamic scan is 30s after stimulation starts, the time of single MR DWI scan is 1min30s, and the interval is 30 s;

s4: DW-MRI post-treatment method: processing DW-MRI original images by adopting Extended MR word Space software of Philips company, wherein outlines of bilateral parotid gland, submandibular gland and sublingual gland are sketched on each image by adopting an ROI method, including all gland parenchyma, the outline is avoided from great vessels and ducts, SI (signal intensity) of each salivary gland on each layer of image is measured, the SI of each layer of gland is averaged, and the measured SI is substituted into a formula to obtain an ADC value after resting and stimulation, wherein the formula is as follows: ADC ═ ln (SI)₁/SI₂)]/(b₂-b₁) Wherein b is₁And b₂For corresponding b value, SI₁And SI₂Respectively, the signal intensity at the time of the b value is taken, the maximum ADC value increase rate after stimulation is (maximum ADC value after stimulation-ADC value before stimulation)/ADC value before stimulation, Tmax (ADC peak time) is the time from the start of taste stimulation to the maximum ADC value after stimulation, the ADC value of each glandular body on one side, the maximum ADC value IR after stimulation and Tmax are calculated, the average values are taken on two sides, drawing an ADC value-time change curve according to the ADC value of each salivary gland at each time point before and after stimulation, wherein the peak value corresponds to Tmax and the maximum ADC value after stimulation, respectively recording the average resting ADC value, the maximum ADC value after stimulation, the maximum ADC value IR and Tmax after stimulation of each gland before and after radiotherapy, calculating the difference rate of the resting ADC value and the maximum ADC value after stimulation of each gland before and after radiotherapy, wherein the difference rate between the resting ADC value of each gland and the maximum ADC value after stimulation before and after radiotherapy is calculated by the following formula: rADC_{Salivary gland}(％)＝(ADC_{After radiotherapy}–ADC_{Before radiotherapy})/ADC_{Before radiotherapy}；

S5: measurement of saliva flow rate: obtaining flow rate of saliva at different time and other saliva data by calculation, wherein the flow rate of saliva at rest is calculated by cotton roll method, the cotton roll method is that cotton rolls with the size of 1.0cm multiplied by 1.2cm are weighed in advance and then placed in mouth for each big salivaCollecting at the gland opening, weighing again after 5min, respectively measuring the amount of parotid saliva on the left side and the right side at rest and the amount of the sublingual gland mixed saliva, adding the two to obtain the total gland saliva amount, calculating the saliva flow rate after stimulation by adopting a lemon juice stimulation method, calculating by adopting a lap method, calculating the saliva flow rate after rest and stimulation by taking the unit of g/min, recording the saliva flow rate change rate (%) after saliva flow rate stimulation-saliva flow rate rest/saliva flow rate rest, recording the resting saliva flow rate before and after radiotherapy of parotid gland, sublingual gland and total gland, the saliva flow rate after stimulation and the saliva flow rate change rate after stimulation, and calculating the difference rate of the resting saliva flow rate of parotid, sublingual gland and total gland before and after radiotherapy by the formula: saliva flow rate difference (%) (saliva flow rate)_{After radiotherapy}Salivary flow Rate_{Before radiotherapy}) Flow Rate of saliva_{Before radiotherapy}；

S6: evaluation mechanism: the salivary gland function and the xerostomia of the patient are evaluated more comprehensively and individually by adopting a salivary flow rate measurement and a grading and grading method of the xerostomia, wherein the grading and grading method of the xerostomia comprises a grading standard of tumor treatment toxicity xerostomia, a visual simulation grading method and a questionnaire, wherein the grading standard of the tumor treatment toxicity xerostomia is graded by a static salivary flow rate value, mild xerostomia is judged by no obvious change of eating habits and the static salivary flow rate is more than 0.2ml/min, moderate xerostomia is judged by obvious change of eating habits (half-flow or diet) and the static salivary flow rate is 0.1-0.2ml/min, oral cavity feeding is not realized, nasal feeding tube or vein nutrition is needed, and the severe xerostomia is judged by the static salivary flow rate is less than 0.1ml/min, the visual simulation grading method is that the symptom position of the patient is marked on a transverse line according to the self xerostomia condition, the evaluator then measures the length from point 0 to the mark point and divides the length of the whole horizontal line to obtain the corresponding ratio as the score of the patient visual simulation rating method, the questionnaire is an XQ Questionnaire (XQ) established by the university of Michigan, USA, and the degree of the dry mouth symptom is judged by the score by scoring 8 questions about the dry mouth symptom, each question having a score of 0 to 10, and the more serious the dry mouth symptom the higher the score.

Comparative example 1

The difference from the first embodiment is that, S3: dynamic DW-MRI examination technique after transient gustatory stimulation: and (3) carrying out examination after transient taste stimulation on the selected experimental object by adopting an MRI technology, wherein 16-channel head and neck combined phased array control coils are adopted, all patients are subjected to DW-MRI examination on parotid gland, submandibular gland and sublingual gland before and after IMRT, the supine position is taken during scanning, the scanning range comprises the parotid gland, the submandibular gland and the sublingual gland on two sides, and the rest is the same as the first embodiment.

Comparative example No. two

The difference from the first embodiment is that, S4: DW-MRI post-treatment method: processing DW-MRI original images by adopting Extended MR word Space software of Philips company, wherein outlines of bilateral parotid gland, submandibular gland and sublingual gland are sketched on each image by adopting an ROI method, including all gland parenchyma, the outline is avoided from great vessels and ducts, SI (signal intensity) of each salivary gland on each layer of image is measured, the SI of each layer of gland is averaged, and the measured SI is substituted into a formula to obtain an ADC value after resting and stimulation, wherein the formula is as follows: ADC ═ ln (SI)₁/SI₂)]/(b₂-b₁) Wherein b is₁And b₂For corresponding b value, SI₁And SI₂The signal intensity at the time of the value b, the maximum ADC value increase rate after stimulation (maximum ADC value after stimulation-ADC value before stimulation)/ADC value before stimulation, Tmax (ADC peak time) is the time from the start of taste stimulation to the maximum ADC value after stimulation, the ADC value of each glandular organ on one side, the maximum ADC value IR after stimulation, and Tmax were calculated, and the average values were taken on both sides, and the rest was the same as in the first example.

Comparative example No. three

The difference from the first embodiment is that, S6: evaluation mechanism: adopts a saliva flow rate measurement and xerostomia grading and scoring method to carry out more comprehensive and individual evaluation on the salivary gland function and the xerostomia of the patient, wherein the grading and scoring method of the dry mouth disease comprises a visual simulation grading method and a questionnaire, wherein the visual simulation grading method is that the patient can perform grading according to the dry mouth condition, the position of the symptom is marked on the horizontal line, and then the evaluator measures the length from the 0 point to the marked point, and dividing the length of the entire horizontal line to obtain a corresponding ratio as a score of the patient visual simulation rating method, wherein the questionnaire is an XQ Questionnaire (XQ) established at the university of Michigan, by scoring 8 questions about dry mouth symptoms, each question scoring 0-10, the degree of dry mouth symptoms is judged by the score, and the heavier the dry mouth symptoms, the higher the score, and the rest is the same as the first embodiment.

Examples of the experiments

The evaluation methods mainly based on magnetic resonance diffusion weighted imaging after short-lived taste stimulation in the first embodiment, the second embodiment, the third embodiment, the fourth embodiment and the fifth embodiment are tested, and the results are as follows:

compared with the existing evaluation method, the evaluation accuracy of the magnetic resonance diffusion weighted imaging-based evaluation method after transient taste stimulation prepared in the first embodiment, the second embodiment, the third embodiment, the fourth embodiment and the fifth embodiment is obviously improved, and the first embodiment is the best embodiment.

Detection reporting

The invention aims to solve the problems that the accuracy of the existing evaluation method is low, the dynamic DW-MRI method after taste stimulation is inconsistent, the commonly-used buccal administration method of vitamin C tablets is easy to cause measurement errors and the like, and the magnetic resonance diffusion weighted imaging after transient taste stimulation is taken as a main evaluation method. After stimulation, ADC values reach a peak when the salivary glands are scanned for the first time (30s) after taste stimulation, and then the ADC values are in a slow descending trend, the reaction of acid stimulation to the salivary glands of most nasopharyngeal carcinoma patients after radiotherapy and the mode of the reaction are still remained, however, the research of adopting the vitamin C tablets as the stimulators discovers that the ADC values lose the original trend after the stimulation to the parotid gland and the submandibular glands after the radiotherapy, and the inconsistency is considered to be due to the types of the stimulators and the difference of time periods after the radiotherapy of case groups, which also prompts that the damage to nerves of the radiotherapy is not a main factor in a radioactive salivary gland damage mechanism, in the application process, the ADC value peak value after the stimulation of part of the patients after the radiotherapy is found to be delayed and possibly occur at a certain time point, a certain time point or all time points after the radiotherapy, which prompts that the patients have nerve damage to cause the reduction of the sensitivity of the salivary glands to the taste stimulation, and years of clinical application practice, we have found that: the correlation between the normal salivary gland ADC value and salivary flow rate is better, the ADC value after taste stimulation is obviously increased, the normal secretion function of the salivary gland can be reflected, the resting ADC value and the maximum ADC value after stimulation of each salivary gland after radiotherapy are obviously increased compared with those before radiotherapy, the increase of the ADC value is prompted to indirectly reflect the damage of the salivary gland after irradiation, no correlation is displayed between the salivary gland ADC value and the salivary flow rate after radiotherapy, the increase of the ADC value is a comprehensive reflection of the damage change after the salivary gland radiotherapy at the moment, but not only the secretion function of the salivary gland, the ADC value increase rate after taste stimulation of each salivary gland of most patients is not different before and after the radiotherapy, the residual function of the salivary gland and the compensation and repair capability after the damage are prompted, the change rate of the ADC value after taste stimulation of the salivary gland shows a certain correlation with the XQ questionnaire table, the method is a comprehensive method for evaluating salivary gland functions of nasopharyngeal carcinoma patients after radiotherapy by mainly using DW-MRI after transient taste stimulation of lemon juice and combining salivary flow rate measurement and grading of various xerostomia grades, which is improved by considering the advantages and disadvantages of the methods, can be further used for evaluating salivary gland image characteristics, function changes, severity and grading of common lesions causing xerostomia, distinguishes the patients with the radioactive xerostomia caused by different factors and guides clinical treatment to adopt corresponding treatment, can develop a new route for improving the diagnosis and clinical research of the radioactive xerostomia, and has clinical practical value of popularization and application in a wider range.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.