Two-Dimensional Ultrasound and Shear Wave Elastography in Infants With Late-Referral Congenital Muscular Torticollis

Objectives To investigate the feasibility of using 2-dimensional ultrasound (US) and shear wave elastography (SWE) to evaluate infants with late-referral congenital muscular torticollis (CMT). Methods A total of 46 infants with late-referral CMT were enrolled and divided into 4 groups according to the degree of the passive range of motion (PROM) deficit in neck rotation. We introduced 6 metrics to represent the US features of the sternocleidomastoid muscle detected by 2-dimensional US and SWE studies. Results There were no significant differences in the age at referral, sex, weight, or side of involvement between the 4 groups (P > .05). The thickness and shear modulus of the involved sternocleidomastoid muscle were positively correlated with the degree of the PROM deficit in neck rotation in late-referral infants with CMT (r = 0.71 and 0.82, respectively; P < .01). However, the difference in the shear modulus between adjacent PROM-limited groups of late-referral infants was not as significant as that of early-referral infants. Conclusions The shear modulus ratio may be one of the best diagnostic indicators of CMT available. However, more effective differential diagnostic SWE indicators late-referral infants with CMT need to be further explored.