[Direct and Indirect Methods of High-frequency Ultrasound in Imaging Distal Biceps Brachii Tendon]

Objective To explore convenient and effective ultrasound scanning methods and skills for imaging the distal biceps tendon.Methods Totally 80 distal biceps tendons of 40 healthy volunteers were scanned and evaluated with high-frequency ultrasound using the direct and the indirect methods. The scanning time and the subjective comfort scores of each subject were recorded. The imaging clarity of the tendon and its insertion onto the radial tuberosity was evaluated.Results The scanning time of the indirect method was shorter than that of the direct method in all volunteers,male volunteers,and female volunteers,although the differences were not statistically significant(all P> 0.05). The mean scanning time was longer on the left side than on the right side regardless of the scanning method (all P> 0.05). The scanning time in women was significantly shorter than in men when the scan was performed by using indirect method on the left side (t=-2.33,P=0.025),direct method on the right side (t=-3.35,P=0.002),or indirect method on the right side (t=-2.67,P=0.011). However,the scanning time was not significantly different between women and men when using the direct method on the left side (t=-1.27,P=0.213). The subjective comfort score was not significantly different between direct and indirect methods in each group (all P>0.05). However,the subjective comfort score was higher on the right side than on the left side regardless of the methods used. In particular,the subjective comfort scores showed significant difference when using the direct method in all subjects (t=2.32,P=0.026),the indirect method in all subjects (t=3.08,P=0.004),and indirect method in females (t=2.52,P=0.021). The overall subjective comfort score of females was higher than that of males,and the difference was statistically significant when the direct method was used on the right side (t=2.33,P=0.025),although no significant difference was observed for the indirect method on the right side (t=2.00,P=0.053),direct method on the left side (t=0.34,P=0.739),and indirect method on the left side (t=-0.15,P=0.884). The clarity rates of the indirect method for the insertions were 100.0% and 95.0%,which were significantly higher than those of the direct method(right side:100.0% vs. 85.0%,P=0.026;left side:95.0% vs.60.0%,P=0.000). The clarity rates of the main trunk of the tendon showed no significant difference between direct and indirect methods on both sides (right side:100.0% vs.95.0%,P=0.494;left side:92.5% vs.87.5%,P=0.712).Conclusions When high-frequency ultrasound is applied for scanning the distal biceps tendon,the scanning time and the subjective comfort are similar when either the direct method or the indirect method is used. The indirect method has higher clarity in imaging the insertion and may be used as the preferred scanning method,whereas the direct method may serve as a supplementary method.