To assess ultrasound intrascan variability and the potential error rate of serial ultrasounds in the diagnosis of deep venous thrombosis in children.
A retrospective cohort review of imaging results of children having at least 3 serial ultrasound examinations of the same region within a 2-month period. The results were interpreted as either (1) inadequately visualized or (2) the absence or presence of deep venous thrombosis, and were categorized by location. Serial imaging findings then were further categorized based on results and clinical information.
Sixty-four patients and 157 vessel segments were included in the study. Deep venous thrombosis was documented in 58 patients. Concordant results were observed in 26 patients (40.1%), clot resolution in 17 patients (26.6%), clot formation in 12 patients (18.8%), and discordant results in 9 patients (14%). Twenty-one of 64 patients (32.8%) had at least 1 vessel inadequately imaged.
The inconsistency of serial ultrasound results in up to 25% of patients calls attention to the potential inaccuracy of ultrasound for diagnosis and follow-up of deep venous thrombosis in children. The high proportion of patients with at least 1 inadequately visualized vessel also highlights the limitation of ultrasound in the diagnosis of pediatric deep venous thrombosis.