BACKGROUNDDifferential diagnosis of isolated calf muscle vein thrombosis (ICMVT) and gastrocnemius hematoma is essential for early identification of deep vein thrombosis (DVT). This study aimed to investigate the diagnostic value of high-frequency color Doppler ultrasound for differential diagnosis of ICMVT and gastrocnemius hematoma.

METHODSA retrospective case series of 35 ICMVT (M:F, 21:14; mean age (64.5 ± 10.6) years) and 23 gastrocnemius hematoma (M:F, 16:7; mean age (75.4 ± 11.8) years) patients with bilateral/unilateral lower limb pain was conducted between January 2006 and September 2012. Characteristics and the morphology of high-frequency color Doppler ultrasonography of the lower limb deep vein, great saphenous vein, calf muscles, skin, and soft tissue were examined.

RESULTSICMVT hypoechoic signals were characterized by long, tube-like masses on longitudinal sections and oval masses on transverse sections, with apparent muscle thrombosis boundaries, distal and proximal venous connections, and, often, lower limb DVT. Gastrocnemius hematoma hypoechoic signals were characterized by large volumes, enhanced posterior hematoma echo, hyperechoic muscle boundaries, no hematoma blood flow, and no DVT, and clear differences in trauma/exercise- and oral anticoagulant-induced hematomas were readily apparent. According to the measurement, the ratio of long diameter/transverse diameter (D/T) in ICMVT patients was about less than 2.0, whereas in gastrocnemius hematoma patients the ratio was more than 2.0. Early stage isoechoic and hypoechoic signals were detected with gradually increasing ovular anechoic areas. Partial muscle fibers in the hematoma due to muscle fractures were apparent.

CONCLUSIONHigh-frequency color Doppler ultrasound was found to be a sensitive and reliable method for differential diagnosis of ICMVT and gastrocnemius hematoma due to trauma and exercise or prolonged oral anticoagulant use.