Value Of Contrast-enhanced Ultrasound And Conventional Ultrasound In The Diagnosis Of Papillary Benign And Malignant Thyroid Nodules

Object:To explore the conventional ultrasound and contrast-enhanced ultrasound commonly used in clinic to judge the benign and malignant of preoperative thyroid micro-nodules,this paper compares the ultrasound examination methods commonly used after the clinical detection of thyroid micro-nodules,and evaluates which method is more reasonable and effective,so as to guide the clinical application.Methods:Sixty patients who suspected of thyroid micronodules were selected from the first affiliated hospital of Shihezi University Medical College from January 2017 to December 2019.Among the 60 patients,19 were males and 41 were females,aged 27-63 years,mean(50.03±7.84)years old.The diameter of the lesion ranged from 0.15 to 0.9cm,mean(0.67±0.21)cm.The course of disease was 2 to 3weeks,mean(2.23±0.42)weeks.All patients received ultrasound and contrast-enhanced ultrasound after admission,and underwent surgical and pathological diagnosis after completing relevant examinations.To evaluate the clinical application value of conventional ultrasound(US)examination and contrast-enhanced ultrasound(CEUS)examination respectively.At the same time,the relationship between blood flow signals and benign and malignant thyroid nodules was studied by contrast-enhanced ultrasound and pathological diagnosis.Results:According to the analysis of surgical pathology,47 of the 60 patients had PTMC,and 13 had other diseases.The results of conventional ultrasonic diagnosis were 42 patients with PTMC and 18 patients with other diseases.The results of CEUS were 47 patients with PTMC and 13 patients with other diseases.The diagnosis accuracy,missed diagnosis rate,misdiagnosis rate,specificity and sensitivity of conventional ultrasound,contrast-enhanced ultrasound and conventional ultrasound + contrast-enhanced ultrasound were compared with the gold standard of surgical pathology diagnosis.Accuracy =(true positive + true negative)/total cases ×100%,sensitivity = true positive/(true positive + false positive)×100%,specificity =true negative/(false negative + true negative)×100%.In the US examination,the malignant nodules showed spot-like calcification,aspect ratio > 1,unclear boundary and hypoechoic.The benign nodules show clear boundaries,large calcification foci,aspect ratio < 1,and mixed echoes.In CEUS examination,benign nodules were mostly manifested as non-uniform and low enhancement.After contrast enhancement,the boundary was clear,and the area remained unchanged after enhancement.Malignant nodules are characterized by uneven low enhancement,unclear boundary after enhancement,and reduced area after enhancement.Ultrasonography showed that in the confirmed PTMC cases,59.6%(28/47)had spot-like calcification,87.2%(41/47)had an unclear boundary with aspect ratio > 1,40.4%(19/47),97.8%(46/47)was hypoechoic,and 85.1%(40/47)was hypoechoic.Among the benign nodules,62.5%(5/8)had complete boundaries,50.0%(4/8)had large calcification foci,75.0%(6/8)had aspect ratio < 1,and 61.1%(11/18)was hypoechoic.Among the benign nodules detected by CEUS,87.5%(7/8)showed non-uniform and low enhancement,75.0%(6/8)showed clear boundaries after contrast enhancement,and 87.5%(7/8)showedunchanged area after enhancement.Among the malignant nodules,88.8%(38/47)showed uneven and low enhancement,68.1%(32/47)showed unclear boundary after enhancement,and 78.8%(37/47)showed decreased area after enhancement.The coincidence rate of US examination was 85.1%(40/47),the coincidence rate of CEUS examination was 95.7%(45/47),higher than the former,with statistically significant difference(P < 0.05).Conclusion :(1)In the clinical diagnosis of thyroid microcarcinoma,the conventional methods or contrast-enhanced ultrasound have high accuracy and specificity.However,the accuracy of contrast-enhanced ultrasound is higher than that of conventional ultrasound.As a further examination method of conventional ultrasound,contrast-enhanced ultrasound is desirable and satisfactory,so it is worth promoting.(2)The lack of blood supply in the micronodules is not an independent basis for the diagnosis of thyroid micropapillary carcinoma.