LAUSR

To the Editor: We appreciated the paper of Francica et al, entitled: Role of Contrast-Enhanced Ultrasound in the Detection of Complications After Ultrasound-Guided Liver Interventional Procedures. The authors clearly highlighted utility of contrast-enhanced ultrasound (CEUS) during and after percutaneous ultrasound-guided diagnostic and therapeutic liver procedures. Among the various subchapters of the article, we would like to focus and analyze the possible hemorrhagic vascular complications, in particular detecting by CEUS of intraparenchymal microbubble flow signal along the needle tract after liver biopsy. There are just few studies in the literature conduced where it is demonstration on CEUS. We confirm that intraparenchymal flow signal along needle tract is also possible to be evaluate with the ultrasound power Doppler (Figure 1A–D) and is called “patent track” sign. The presence of either pulsatile arterial or venous waveforms in the patent track is not statistically associated with the severity of hemorrhage. The ultrasound power Doppler track flow signal typically has no significant clinical relapses unless associated with other signs, as perihepatic focal or diffuse fluid collection. As in CEUS, the ultrasound power Doppler track flow signal disappeared within 5 minutes after biopsy procedure. Moreover, if it persists beyond