To investigate the shear wave velocity changes of the gastrocnemius and soleus muscles in diabetic patients by using virtual touch tissue quantification (VTQ).

VTQ was used to examine 35 patients with diabetes and 22 healthy people to measure the shear wave velocity of the anterior and lateral heads of the gastrocnemius muscle and the shear wave velocity of the soleus muscle at the natural position of the ankle, the maximum dorsal flexion, and the maximum plantar flexion. The shear wave velocities of different calf muscles in the same position in the diabetic group, as well as the shear wave velocity of calf muscles in the same position between the diabetic group and the normal control group were compared. Meanwhile, the test-retest reliability of shear wave elastrography was also analyzed.

The shear wave velocities of the medial head of the gastrocnemius muscle, the lateral head of the gastrocnemius muscle, and the soleus muscle of the left and right calves showed no statistical difference (P>0.05). At the same ankle position, there was no significant difference in shear wave velocity between the medial head of the gastrocnemius muscle and the lateral head of the gastrocnemius muscle in the diabetic group (P>0.01). The shear wave velocities of the medial gastrocnemius muscle and the soleus muscle were significantly different in the three positions (H=35.348, 52.364, 30.348, 45.697, 51.621, 39.318, all P<0.001), while the shear wave velocities of the lateral gastrocnemius muscle and the soleus muscle were different only at the maximum dorsal flexion (H=46.636, 47.288, all P<0.001). There were significant differences in the shear wave velocities of the medial head of calf gastrocnemius muscle, the lateral head of gastrocnemius muscle, and the soleus muscle between the normal group and diabetic patients, at normal ankle position, maximum dorsal flexion position, and maximum plantar flexion position (t=2.768, 4.110, 2.202, 10.852, 2.246, 2.682, 2.493, 2.541, 2.355, 2.139, Z=-3.203, 2.829, -2.698, -2.912, -3.185, -3.177, -5.439, -2.796, all P<0.05). The shear wave velocities of the gastrocnemius muscle and soleus muscle at the three different positions all had excellent test-retest reliability as intraclass correlation coefficients (ICC) were all larger than 0.75.

Diabetes may decrease the shear wave velocities of the medial head of calf gastrocnemius muscle and the lateral head of the gastrocnemius muscle and soleus muscle. The shear wave velocity of the medial head of the gastrocnemius muscle and the lateral heads of the gastrocnemius muscle and the soleus muscle are affected by the position of the ankle, and the shear wave velocities of different muscles are also different.