Study On The Value Of Acoustic Radiation Force Impulse Technology For Differentiating Between Benign And Malignant Thyroid Nodules

PART I Study on the Value of Acoustic Radiation Force Impulse Imaging Technology for Differentiating Between Benign and Malignant Thyroid Nodules1. ObjectiveThe study aimed to evaluate the diagnostic value of Virtual Touch tissue quantification (VTQ) of acoustic radiation force impulse (ARFI) elasticity imaging for differentiating between benign and malignant thyroid lesions. We hope to obtain the VTQ parameter range of thyroid nodules and ideal shear wave velocity (SWV) threshold with VTQ technology to reduce unnecessary biopsy or surgical injury.2. Method2.1. Cases data268hospitalized patients(167female and101male, mean age of48.9years range from18years to75years) with312thyroid nodules undergoing thyroid nodules surgery or biopsies were evaluated, during September,2011to October,2012year in Qilu Hospital of Shandong University. Serum-free thyroxine and thyrotropin levels were normal in all patients. After routine thyroid sonography, the patients underwent VTQ of ARFI elasticity imaging examination.All patients were informed and agreed to participate before the ARFI examination.2.2. Instrument and parametersAn AcusonS2000diagnostic ultrasound system (Siemens Medical Solution, Mountain View, California, USA) with ARFI imaging software and9L4high-frequency probes with a central frequency of9MHz was used. In the VTQ model, the region of interest (ROI)(5x6mm) was placed inside the nodule and the depth of the ROI was placed from0.5cm to4cm from skin surface.2.3. Examination methodsPatients were in supine position with neck fully exposed. Conventional sonography was used to observe each nodule’s morphologic characteristics, size, boundary, echoes, and color Doppler features etc. All the results were recorded in detail. After routine thyroid sonography, VTQ were used. All patients undergoing ARFI examinations were asked to hold their breath with probe lightly touching the skin of the thyroid in vertical position avoiding artery pulsation, then the VTQ function was in proccess. VTQ value of the internal and its surrounding tissues were obtained. Three ROI for detection with VTQ were performed to each thyroid nodule. Each ROI of thyroid nodules was randomly measured7times continuously. The highest and the lowest value were abandoned. The SWV value of the rest5times were taken into account, and calculated the average value as the VTQ value (m/s). All data were recorded and figured respectively.2.4. Statistical analysis methods SPSS version10.0software was used. All data were presented as the mean±SD. For statistical analysis, the Student t test, analysis of variance, and the X2test were used.2-sides p<0.05was considered statisticlly significant.3. ResultsAccording to the gold standard by pathological results, all cases were divided into four groups:group for benign, group for malignant, parenchyma surrounding benign nodules and parenchyma surrounding malignant nodules.Of the312thyroid nodules observed in268hospitalized patients,196were benign and116malignancy, with mean±SD of2.67±0.68m/s(range from1.12m/s to4.14m/s) and4.43±0.98m/s(range from2.08m/s to7.51m/s), respectively. Parenchyma surrounding benign nodules and parenchyma surrounding malignant nodules were of2.58±0.56m/s(range from0.95m/s to3.46m/s)and2.47±0.67m/s (range from0.88m/s to3.48m/s), respectively.●There was no significant difference between the VTQ value of benign nodules and that of the parenchyma surrounding nodules(P=0.351).●There was significant difference between the VTQ value of malignant nodules and that of the parenchyma surrounding nodules(P=0.025).●There was no significant difference between the VTQ value of the parenchyma surrounding benign nodules and that of the parenchyma surrounding malignant(P=0.158).●There was significant difference between the VTQ value of benign nodules and that of the malignant(P=0.035).●According to the Receiver operating characteristic(ROC) curve, we can determine the best point for diagnostic value of3.25m/s, corresponding to the sensitivity and specificity of89%and70%, respectively.4. ConclusionsVTQ of ARFI technology was objective in quantitatively evaluating tissue hardness. It provided a new clinical diagnosis method for thyroid nodal diseases and was a supplements for the traditional way. ARFI technology has better diagnostic value in the evaluation of benign and malignant thyroid nodules. PART Ⅱ The effects of thyroid nodules’size on ARFI accuracy1. ObjectivesThe study aimed to explore VTQ of ARFI diagnosis coincidence rate in thyroid nodules with different size. We expect to improve the differential diagnosis of thyroid nodules between the benign and the malignant with the new diagnostic techniques.2. Method2.1. Cases data268hospitalized patients(167female and101male, mean age of48.9years range from18years to75years) with312thyroid nodules undergoing thyroid nodules surgery or biopsies were evaluated, during September,2011to October,2012year in Qilu Hospital of Shandong University. Serum-free thyroxine and thyrotropin levels were normal in all patients. After routine thyroid sonography, the patients underwent VTQ of ARFI elasticity imaging examination.All patients were informed and agreed to participate before the Examination.According to the nodal diameter,312cases of thyroid nodules were divided into four groups:50cases of diameter less than1.0cm,118cases of diameter range from1.1cm to2.0cm,75cases of diameter range from2.1cm to3.0cm and69cases of nodules diameter greater than3.0cm.2.2. Instrument and parametersAn AcusonS2000diagnostic ultrasound system (Siemens Medical Solution, Mountain View, California, USA) with ARFI imaging software and9L4high-frequency probes with a central frequency of9MHz was used. In the VTQ model, the region of interest (ROI)(5x6mm) was placed inside the nodule and the depth of the ROI was placed from0.5cm to4cm from skin surface.2.3. Examination methodsPatients were in supine position with neck fully exposed. Conventional sonography was used to observe each nodule’s morphologic characteristics, size, boundary, echoes, and color Doppler features etc. All the results were recorded in detail. After routine thyroid sonography, VTQ were used. All patients who undergoing ARFI examinations were asked to hold their breath with probe lightly touching the skin of the thyroid in vertical position avoiding artery pulsation, then the VTQ function was in proccess. VTQ value of the internal tissues were obtained. Three ROI for detection with VTQ were performed to each thyroid nodule. Each ROI of thyroid nodules was randomly measured7times continuously. The highest and the lowest value were abandoned. The SWV value of the rest5times were taken into account, and calculated the average value as the VTQ value (m/s). All data were recorded and figured respectively.2.4. Statistical analysis methodsSPSS version10.0software was used. All data were presented as the mean±SD. For statistical analysis, analysis of variance, and the X2test were used.3. ResultsThe pathology was regarded as the gold standard for diagnose. According to the nodal diameter, all nodules were divided into four groups:group for modular diameter less than1.0cm, group for nodules diameter range from1.1cm to2.0cm, group for nodules diameter range from2.1cm to3.0cm, group for nodules diameter greater than3.0cm. Corresponding to each group, accurate diagnosis of cases were7cases respectively(including6cases of benign and1case of malignant),85cases (including45cases of benign and40cases of malignant),46cases(including21cases of benign and25cases of malignant),39cases (including23cases of benign and16cases of malignant).●In the group of nodular diameter less than1.0cm, VTQ sensitivity, specificity, misdiagnosis rate, false dismissal rate. You-den index, Odds product, Negative predictive value, Positive predictive value were5.3%,19.4%,80.6%,19.4%,-75%,75.3%,3.85%and25.00%. respectively.●In the group of nodular diameter in range from1.1cm to2.0cm, VTQ sensitivity, specificity, the misdiagnosis rate, false dismissal rate, You-den index, Odds product, Negative predictive value, Positive predictive value88.9%,61.6%,38.4%,61.6%.51%,4.98%,58.82%and4.98%. respectively.●In the group of nodular diameter in range from2.1cm to3.0cm. VTQ sensitivity, specificity, misdiagnosis rate, false dismissal rate, You-den index. Odds product, Negative predictive value, Positive predictive value were64.1%,58.3%,41.7%,58.3%,22%,1.28%,62.50%and1.28%, respectively.●In the group of nodular diameter greater than3.0cm, VTQ sensitivity, specificity, misdiagnosis rate, false dismissal rate, You-den index, Odds product, Negative predictive value, Positive predictive value were59.3%,54.8%,50.7%,54.8%,14%,1.20%,45.71%and1.20%, respectively.●The accordant diagnostic rate of diameter in the range from1.1cm to2.0cm was highest up to72.03%. The accordant diagnostic rate of diameter in the range from2.1cm to3.0cm was higher up to61.33%. The accordant diagnostic rate of diameter less than1.0cm was lowest down to14.00%.5. ConclusionsVTQ technology showed the highest significance with diameter range from1.1cm to3.0cm. In some thyroid nodules with the diameter greater than3.0cm, VTQ showed lower significance, but, in ultrasound-guide biopsy and surgical location, it showed higher value for improving the biopsy and positive rate.