Research Of Contrast-enhanced Ultrasound In The Diagnostic Value Of Thyroid Cancer

Objectives 1.By means of Thyroid Imaging Reporting and Data System(TI-RADS) in 130 thyroid disease patients,we discussed the diagnostic value of this classifi cation method and concluded the possible classification features of benign and malignant lesions. 2.By realizing CEUS(contrast-enhanced ultrasound) among 130 thyroid disease patients,we learnt its diagnostic value in thyroid benign and malignant lesions.Then the comparison with TI-RADS and the joint diagnosis with it were made in order to know their discrepancy and related value. 3.By performing CEUS among 116 patients with TI-RADS 4,we explored its related application value. 4.By concluding the CEUS data among 100 patients with malignant path ological diagnosis,we researched the relation between thyroid cancer size and different CEUS features.Material and methods 1. Screening of objects Ultrasonic examinations(US、CEUS) were done among 130 patients with suspected thyroid lesions and their diagnosis were compared with pathological golden standard(got by means of FNAB or direct surgical excision).Ultrasonic examinations were performed with SEQUOIA 512 ultrasound system produced by Germany Simens company with the linear array probe type 15L8 W,whose frequency is 14 MHz. The frequency of CEUS probe is 7MHz.CEUS presets were adjusted as follows:mechanical index(MI)0.31,total gain 5,depth 4cm,and the focus distal to the lesion.After a bolus administration of 1.5m L Sono Vue through the antecubital vein,the CEUS examination was recorded digitally. 2. The analysis of TI-RADS among the objects The TI-RADS classification and comparison with the pathological results were retrospectively performed among the patients mentioned above.We calculated its diagnostic efficiency and analyzed the misdiagnosed cases with the aim of exposing its possible existing deficiencies and concluding the possible ultrasonogram features of these lesions. 3.The analysis of CEUS and joint diagnosis among the objects The widely accepted CEUS diagnostic criteria was made according to several authors’ articles[15-18] in the past.Then CEUS analysis was retrospectively accomplished among these patients.By statistical methods,we got the diagnostic efficiency of CEUS and joint diagnosis.The diagnostic efficiency of TI-RADS、CEUS and joint diagnosis were compared in order to know their diagnostic value for thyroid lesions. 4.The analysis of CEUS for lesions with TI-RADS 4 For the purpose of further knowing the benignity and malignity of thyroid lesions with TI-RADS 4,CEUS were retrospectively accomplished among these lesions.The final diagnosis was in accordance with the CEUS results,whose correcting effect for TI-RADS 4 possibly malignant lesions was evaluated. 5.The exploration of the relation between thyroid cancer size and CEUS features Selecting the malignant thyroid lesions according to the existing pathologi cal results,grouping separately these lesions into three groups according to thei r size(≤5mm、5-10mm(including 10mm) and >10mm) and finally studying ret rospectively the relation between the CEUS features and the size of the lesion s according to the distribution of the known CEUS features in different group s of the lesions.Results 1.Screening of objects The screening of the objects was made according to the steps above,finally 130 patients were suitably recruited into this research,among which 22 were male and 108 were female.Their age ranged from 21 to 77 years old,with the mean age of 49 years old. The total number of lesions was 157,among which 42 were benign and 115 were malignant. 2. Ultrasonic TI-RADS classification among the objects 1)Among these malignant lesions, 1 lesion belonged to TI-RADS 2; 0 lesion belonged to TI-RADS 3; 108 lesions belonged to TI-RADS 4,among which 46 were TI-RADS 4A and 62 were 4B; 6 lesions were classified TI-RADS 5. Among these benign lesions, 10 lesions belonged to TI-RADS 2; 3 lesions belonged to TI-RADS 3; 29 lesions belonged to TI-RADS 4,among which 17 were TI-RADS 4A and 12 were 4B; 0 lesion was classified TI-RADS 5. The classification of TI-RADS was made among 157 lesions with the conclusion of malignancy when the classification was 4 or more.By the comparison with the pathological results,we found 29 misdiagnosed lesions and 1 missed lesion.The related diagnostic efficiency was as follows:sensitivity 99.13% 、specificity 30.95%、PPV 79.72%、NPV 92.86% and accuracy 80.89%. 3.The CEUS and joint diagnosis results for the lesions 1)The CEUS results for the lesions Among 115 malignant lesions, 108 ones were correctly diagnosed by CEUS with 7 missing ones.Among 42 benign lesions, 25 ones were rightly diagnosed by CEUS with 17 misdiagnosed. CEUS were realized in 157 lesions with the diagnostic efficiency as follows:sensitivity 93.91%、specificity 59.52%、PPV 86.40%、NPV 78.13% and accuracy 84.71%. 2)The joint diagnosis results for the lesions TI-RADS classification and CEUS examination were done among 157 thyroid lesions.The final diagnosis was malignant when the outcome of the two tests was positive,or a benign diagnosis was achieved.According to such criterion,we got the following results:Among 115 malignant lesions,the combined diagnosis were correct in 107 lesions,with 8 lesions missed;Among 42 benign lesions,28 correct diagnosis were made,with 14 lesions misdiagnosed. 157 thyroid lesions experienced TI-RADS classification and CEUS examination,who got the following combined diagnostic efficiency:sensitivity 93.04%、specificity 66.67%、PPV 88.43%、NPV 77.78% and accuracy 85.99%. 3)The comparison of the diagnostic efficiency among US TI-RADS classification、CEUS and joint diagnosis A table was made to directly compare the diagnostic efficiency of these three methods.Their sensitivities were ranked in this order:TI-RADS classification>CEUS>joint diagnosis;their specificities were in this order:joint diagnosis>CEUS>TI-RADS classification;as to their accuracies:joint diagnosis>CEUS>TI-RADS classification,whose order was the same as the ROC AUC. With the help of the Mc Nemar Chi-square test,we compared the sensiti vity and the specificity for different diagnostic methods and obtained the follo wing outcomes:sensitivity:TI-RADS classification>CEUS>joint diagnosis,the s ensitivities of two adjacent examinations were not statistically significant but t he sensitivity of TI-RADS was obviously higher than that of the joint diagnos is;specificity:joint diagnosis>CEUS>TI-RADS,although the difference of the s pecificities between the joint diagnosis and CEUS were not significant,they w ere evidently higher than that of TI-RADS. Through Z test of ROC AUC,we compared the diagnostic accuracy for different examinations.The results were as follows:joint diagnosis>CEUS>TIRADS classification.Although the ROC AUC of joint diagnosis didn’t statistic ally differ from that of CEUS,it was higher than that of TI-RADS.In addition,ROC AUC of CEUS was statistically higher than that of TI-RADS. 4.The diagnostic results of CEUS for lesions with TI-RADS 4 1)The diagnostic results of CEUS for lesions with TI-RADS 4 Among 108 thyroid lesions pathologically diagnosed malignant and TI-R ADS classified as category 4,101 lesions were jointly diagnosed malignant,with 7 missed ones. Among 29 thyroid lesions pathologically diagnosed benign and TI-RADS classified as category 4,15 lesions were jointly diagnosed benign,with 14 mi sdiagnosed ones. After the CEUS diagnosis among 137 TI-RADS classified category 4 lesions,the combined diagnostic efficiency was as follows:sensitivity 93.51%、specificity 51.72%、PPV 87.83%、NPV 68.18% and accuracy 84.67%.ROC AUC was 0.726,with 95% CI 0.644-0.799. 2)The diagnostic results of CEUS for lesions with TI-RADS 4A Among 63 TI-RADS 4A lesions, there were 46 tumors and 17 benign l esions.CEUS has correctly diagnosed 44 tumors and 8 benign lesions,with 9 misdiagnosed and 2 missed. The diagnostic efficiency for CEUS among TI-RADS 4A lesions was as follows:sensitivity 95.65%、specificity 47.06%、PPV 83.02%、NPV 80.00%、accuracy 82.54% and ROC AUC 0.714 with 95%CI 0.586-0.820. 3)The diagnostic results of CEUS for lesions with TI-RADS 4B Among 74 TI-RADS 4B lesions, there were 62 tumors and 12 benign l esions.CEUS has correctly diagnosed 57 tumors and 7 benign lesions,with 5 misdiagnosed and 5 missed. These were the diagnostic efficiency of CEUS among TI-RADS 4B lesi ons:sensitivity 91.94%、specificity 58.33%、PPV 91.94%、NPV 58.33%、accur acy 86.49% and ROC AUC 0.789 with 95%CI 0.688-0.869. 4)The comparison of CEUS diagnostic efficiency among TI-RADS 4A、4B and 4 lesions In the lesions of TI-RADS 4A、4B and 4,except for NPV,other diagnost ic efficiency were not statistically significant.However,as the classification incr eased,sensitivity and NPV would decrease whereas the other indexes would in crease.Additionally,for category 4 lesions,the diagnostic efficiency was in the middle of all results. 5.The exploration of the relation between the thyroid cancer size and the CEUS features The results showed that in 5mm、10mm groups,as the tumor size increa sed,the proportion of diffuse enhancement would decrease and that of the cent ripetal enhancement would increase.The difference was statistically significant.F or the rest,no matter which group,as shown by Chi-square test,there was no r elation between the tumor size and distribution of CEUS features.However,by observing the percentage,we could find out the following tendency: When the lesions were divided into three groups by 5mm、10mm,as the size increased,the proportion of synchronized enhancement with the thyroid tissue、similar enhancement to the thyroid tissue and homogeneous enhancement would decrease and that of later enhancement than the thyroid tissue、lower enhancement than the thyroid tissue and heterogeneous enhancement would increase.Conclusions 1)During the diagnosis of thyroid lesions,TI-RADS classification has high sensitivity and NPV,thus it can be used as thyroid screening test. 2)As to the diagnostic efficiency of CEUS,it owns relatively high sensitivity and accuracy,as a result,it is a powerful method in diagnosis of thyroid lesions. 3)The joint diagnosis of TI-RADS classification and CEUS has comparatively high sensitivity and accuracy.Thus,it can increase the diagnostic value of ultrasound in thyroid lesions. 4)The CEUS examination of TI-RADS category 4 thyroid lesions shows a comparatively high sensitivity and accuracy.The combination of these two methods can effectively diagnose thyroid cancer、decrease the possibility of misdiagnosis and missed diagnosis and thus guide to some extent the clinical management.In addition,with the increase of TI-RADS classification,the diagnostic value of CEUS has the tendency to increase.. 5)Like the results obtained by YUAN ZHANG,there’s no evident relation between the tumor size and the distribution of CEUS features.Nevertheless,as the tumor size increases,the proportion of later enhancement than the thyroid tissue、centripetal enhancement、lower enhancement than the thyroid tissue、heterogeneous enhancement、non-early fade-out and blurred border when enhancing will increase.