RESUMO
Objective To evaluate the effects of the range and the frequency of the compression load on the accuracy for discerning target stiffness differences in ultrasound elastography.Methods Quantitative ultrasound elastography was achieved by integrating two compression force sensors,a laptop computer and a clinical ultrasound elastographic system.The force sensors and the ultrasound probe were assembled in a 3D printed mounting bracket for continuous monitoring of compression loads during ultrasound elastography. Both the force measurements and the elastographic maps were acquired and displayed on the laptop computer in real time.Four targets of the same diameter(10.4 mm),the same depth (3 cm) and different stiffness levels (8,14,45 and 80 kPa) were examined by a HITACHI preirus,L74M linear-array transducer.Each target was evaluated 45 times with two different method(i.e.,freehand elastography and quantitative elastography),yielding 1 80 evaluations.The data were divided into the following three groups:group Ⅰ(80 kPa vs 45,14 and 8 kPa),group Ⅱ(80,45kPa vs 14,8 kPa)and group Ⅲ(80,45 and 14 kPa vs 8 kPa).Area under ROC curves(AUC)were calculated for different stiffness levels.Results In group Ⅲ, quantitative elastography yielded an greater AUC level than that of freehand elastography(P =0.0379).In group Ⅰ and group Ⅱ,two methods yielded the similar AUC levels (P = 1 .000).However,quantitative elastography was able to discern 8 kPa and 14 kPa targets (P <0.001),while freehand elastography was hard to differentiate them(P =0.258).Conclusions In comparison with freehand elastography,quantitative ultrasound elastography is able to improve the accuracy for discerning different target stiffnesses.
RESUMO
ObjectiveTo evaluate the implication of ultrasonographic features of primary breast cancer tumors and axillary lymph nodes in predicting axillary lymph nodes metastasis in patients with breast cancer.MethodsA total of 108 patients with breast cancer were underwent examination of primary breast tumors and axillary lymph nodes by high frequency linear-array probes of ultrasound.The ages of patients,locations of primary tumors,numbers of tumors,maximum diameters of tumors,the longitudinal transverse axis ratio of tumors,mass boundary,ultrasonic patterns,micro-calcification,classification of blood supply,color pixel density(CPD),peak systolic velocity,resistance index,the longitudinal transverse axis ratio of axillary lymph nodes and maximum cortical thickness of axillary lymph nodes were recorded.ResultsOut of 108 patients with breast cancer,the longitudinal transverse axis ratio of tumor were greater than 1 in 75 (69.4 ％ ),micro-calcification in 57(52.8 ％ ),classification of blood supply were Ⅱ - Ⅲ in 57 (52.8％ ),CPD were greater than or equal to 10％ in 48 (44.4％),maximum cortical thickness of axillary lymph node were greater than or equal to 3 mm in 51 (47.2％),and longitudinal transverse axis ratio of lymph nodes were less than 1.5 in 59 (54.6％).Univariate analysis revealed that these six parameters were correlated to the axillary lymph node metastasis in breast cancer ( P ＜0.05).However,ages of patients,location of tumor in the breast,numbers of tumors,maximum diameters of tumors,mass boundary,ultrasonic patterns,peak systolic velocity and resistance index were not related to the axillary lymph node metastasis( P ＞0.05).Multivariate logistic regression analyses showed that CPD (OR:16.337,95％ CI:4.537- 58.826),longitudinal transverse axis ratio of lymph nodes (OR:3.754,95％ CI:1.269- 11.108) and microcalcificationand (OR:3.033,95 ％ CI:1.040 - 8.840) were risk factors of axillary lymph nodes metastasis in patients with breast cancer.ConclusionsThe application of ultrasonography in patients with breast cancer is useful in predicting axillary lymph nodes metastasis.