Ultrafast shear-wave elastography for pediatric deep vein thrombosis: a prospective feasibility study.

objectiveTo evaluate the feasibility of ultrafast shear-wave elastography (SWE) for quantifying thrombus stiffness in pediatric deep vein thrombosis (DVT), and to explore changes over time. MATERIALS AND

methodsIn this single-center prospective study, pediatric patients (<18 years) with ultrasound-confirmed DVT were prospectively enrolled. Bedside SWE ultrasound was performed using a research platform (Vantage-256, Verasonics, Kirkland, Washington, USA) with a 6.9-MHz linear transducer. Mean shear-wave velocity was computed using MATLAB software. To assess shear-wave velocity (SWV) changes over time (exploratory analysis), SWE was planned at three timepoints (0-5 days, 6 days-6 weeks, and 6-16 weeks from DVT diagnosis). Feasibility was defined as the ability to obtain SWV measures. Changes in SWV over time in patients with ≥2 successful SWE were estimated using generalized estimating equations. The model was adjusted for patient age at DVT and sex.

resultsIn total, 35 patients (median age 1.4 years [range, 0.0-17.6], 63% male) were enrolled. SWE was successful in 19 patients, with a higher frequency of success in older patients and in occlusive DVTs. Fifteen of the 19 patients had ≥2 SWE. We documented an increase in SWV over time, with an increase in mean velocity of 0.012 m/s per day (P<0.001). Older age at DVT and female sex were associated with increased SWV, independent of time from index DVT.

conclusionsUltrafast SWE was feasible in pediatric DVT, particularly in older patients and in those with occlusive DVT. In exploratory longitudinal analyses, SWV increased over time, supporting further investigation of ultrafast SWE as a non-invasive quantitative biomarker of thrombus maturation in children.