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Objective To evaluate and compare the consistency and repeatability of three-dimensional ultrasound (3D-US) virtual organ computer-aided analysis (VOCAL) technique and two-dimensional ultrasound (2D-US) in the measurement of thyroid volume.Methods The thyroid volume of 50 healthy female adults aged 18 to 68 years were measured by 2D-US and 3D-US.The 2D-US was used to measure the three diameter lines (L,H,W) of the largest thyroid section,and the thyroid volume was calculated by the classical ellipsoid formula V=0.523×L×H×W.The 3D-US VOCAL technique was used to acquire the thyroid three-dimensional data,and VOCAL software was used to measure the thyroid volume.The two methods of measurement were also compared and analyzed.Results The coefficient of variation in the intra-assay was 0.738％ and 1.59％ respectively for the 3D-US VOCAL technology and traditional 2D-US measurement of thyroid volume,and the 95％ limit of agreement in the intra-assay was (-0.26 cm3,0.22 cm3) and (-0.32 cm3,0.46 cm3).In addition,the correlation coefficient in the inter-assay were 0.970xx and 0.942xx,and the 95％ limit of agreement were (-0.36 cm3,0.37 cm3) and (-0.75 cm3,0.64 cm3).To compare the two methods of measuring thyroid volume,the 3D-US VOCAL had a lower variation coefficient in the intra-assay,a higher correlation coefficient in the inter-assay and a narrower 95％ limit of agreement,which showed that the repeatability of the 3D-US VOCAL technique measuring was better than the traditional 2D-US in measuring thyroid volume.Conclusions The 3D-US VOCAL technique shows a higher repeatability in measuring thyroid than traditional 2D-US.As a safe,simple and feasible precise measurement method,it provides a reliable and effective new method for clinical measurement of irregular organ volume.
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Objective To assess the reproducibility of vascularization measurement in cervical carcinoma using transvaginal three-dimensional power Doppler angiography (3D-PDA) with virtualorgan computer-aided analysis ( VOCAL), and compare the reproducibility of two different contour mode (manual and automatic mode) of VOCAL. Methods Eighty patients with cervical carcinoma were examined by observer 1 using transvaginal 3D-PDA. The two acquired volume datasets were analyzed using manual and sphere automatic contour mode of the VOCAL imaging program for assessing carcinoma vascularization index( VI), flow index(FI), and vascularization flow index(VFI). Forty patients of them were examined randomly by observer 2 by the same method. Reproducibility of vascularity measurement was assessed by calculating intraclass (intra-CC) and interclass (inter-CC) , limits of agreement, 95% confidence interval definition. The contribution of various factors (examiner, measurement, contour mode and patient) to intrasubject variance was estimated using different analysis of variance models (ANOVA). Results For intraobserver,manual contour mode was more valid than sphere automatic contour mode for each observer (0. 92～0. 99 vs 0. 75～0. 94) ,and it also had smaller standard deviation,narrower limit of agreement range, 95% confidence interval and higher intra-cc than those of sphere automatic contour mode. Interobserver agreement of manual contour vascular measurements was similar to the intraobserver agreement for manual contour vascular measurements ( 0. 89 ～ 0. 97 vs 0. 92 ～ 0. 99 ) , but interobserver agreement for sphere automatic contour vascular measurements dramatically reduced (0. 52～0. 72). Conclusions Manual contour mode for 3D-PDA vascular measurement has better reproduciblity than sphere automatic contour mode, especially useful for irregular shape tissue.
ABSTRACT
OBJECTIVE: The purpose of this study is to verify the correlation between gestational sac volume (GSV) from automatic tracing mode the VOCAL-imaging program and gestational age and to construct the nomogram of gestational sac volume as the new biometric parameter in early pregnancy. METHODS: The cross-sectional study has been conducted in 242 uncomplicated singleton pregnancies. 47 cases were excluded due to early pregnancy failure, fetal malformations, elective abortion, age discrepancy, etc. In 195 uncomplicated singleton pregnancies from 5 to 12 weeks' menstrual age, gestational sac volume, mean sac diameter and crown-lump length were measured for the assessment of gestational age. Gestational sac volumetry was carried out with automatic method and manual method of the VOCALTM (Virtual Organ Computer- aided AnaLysis) for the comparison between two methods. The collected data were analyzed for mean, standard deviation, 90% reference interval, 5th, 50th and 95th percentiles of gestational sac volume, mean sac diameter and CRL, and the nomogram were constructed. RESULTS: Polynomial regression analysis demonstrated the statistically significant positive correlation between gestational age and gestational sac volume by automatic tracing mode (R2 0.826, p<0.001), gestational sac volume by manual tracing mode (R2 0.844, p<0.0001), mean sac diameter (R2 0.763, p<0.0001) and crown-lump length (R2 0.950, p<0.0001). The 5th, 50th and 95th percentiles of the gestational sac volume were calculated and the nomogram was tabulated. In determining gestational age, the standard deviation (SD) of gestational sac volume by automatic tracing mode is 5.6 days, the SD of gestational sac volume by manual tracing mode is 5.2 days and the SD of MSD is 6.6 days. CONCLUSION: we can conclude that three-dimensional GSV with automatic tracing mode of the VOCAL-imaging program can be used as the new biometric measurement in determining gestational age. Gestational sac volumetry with automatic tracing mode of the VOCAL-imaging program have been proven available and convenient method and it can be recommended in 5-7 weeks' of gestation, when CRL is not clearly visualized.