[Digital ultrasonic diagnosis of lower leg venous thrombosis using harmonic imaging and cross beam technology]

Abstract

Purpose: To evaluate the extent to which Tissue Harmonic Imaging (THI) and spatial averaging (Sono-CT, Cross Beam) facilitate the diagnosis of lower leg venous thrombosis.

Materials and methods: In 100 cases of lower leg venous thrombosis, the conventional B-scan, THI, and ultrasonic CT technology (Cross Beam) in examinations using a multi-frequency transducer head (9 - 14 MHz, Logiq 9, GE) were compared during follow-up studies using compression sonography over at least 6 weeks. Two independent examiners performed digital image documentation (PACS connection) without modifying the gray level parameters optimized in the B-scan. A thrombosis was considered to be proven sonographically if at least one ultrasonic modality yielded findings reproducible in follow-up checks at a comparable site in accordance with both examiners.

Results: Thromboses in the V. tibialis posterior category (97 %) and the fibular category (81 %) were found most often, followed by muscular venous thromboses (48 %). Thromboses in the V. tibialis anterior category were rare (12 %). The procedure comparison showed an advantage for ultrasonic CT technology in terms of the demarcation of thromboses of the deeper veins (sensitivity 98 %), as compared to THI (sensitivity 87 %, specificity 91 %, PPV: 99 %) and the B-scan (sensitivity 81 %).

Conclusion: If a high-resolution linear transducer is used, THI and ultrasonic CT-Technology can facilitate the diagnosis of a lower leg venous thrombosis.