Superb microvascular imaging in the visualization of recanalization in deep vein thrombosis

BACKGROUND: The aim of this study was to evaluate the use of the superb microvascular imaging (SMI) technique in the detection of recanalization in deep vein thrombosis (DVT) and to compare the diagnostic value of SMI with that of conventional Doppler imaging (CDI) techniques. METHODS: The study consisted of 30 patients who were admitted to hospital within the first 72 h of a first episode of acute DVT. In total, 78 venous segments of 38 lower extremities were assessed. In all the segments, the venous lumen was totally occluded, intraluminal vascular signals were not detected by any of four vascular imaging techniques (color Doppler [CD], power Doppler [PD], color SMI [cSMI], and monochrome SMI [mSMI]) on admission. All the patients were treated with a standard treatment protocol (low-molecular weight heparin for a minimum of 5 days, followed by treatment with a vitamin K antagonist). One month after the treatment was initiated, grading systems that allowed a qualitative comparison of recanalized blood flow (BF) were applied to assess the performance of the four vascular imaging techniques in the detection of recanalization in the thrombosed venous segments. The diagnostic performances of the four imaging techniques in the detection of recanalized BF were statistically compared. RESULTS: The diagnostic performance of the imaging techniques in the detection of recanalized BF in the thrombosed venous segments was found as follows: mSMI >cSMI >PD >CD. CONCLUSIONS: SMI is a promising and effective method for evaluating the treatment efficacy and may provide more accurate information than CD and PD on recanalized BF in DVT.