To the Editor: We read with great interest the article by Hwang et al1 titled “Ultrasound in Traumatic Spinal Cord Injury: A Wide-Open Field.” The authors have meticulously conducted a comprehensive literature review, intending to present the current state of diagnostic and therapeutic ultrasound in the context of spinal cord injury (SCI) and discuss the future directions and challenges. We want to congratulate the authors for this successful review article and make some contributions. Molecular imaging for intraoperative neurosurgery applications is a promising ultrasound capability.2 It performs real-time in vivo biomarker detection and quantification using protein-specific microcontrast and nanocontrast agents.3 It has the potential to lead to the development of effective diagnostic and treatment alternatives for people with spinal cord injuries. Ultrasound has been used to visualize post-traumatic spinal hematoma in patients with SCI.4 According to research findings, individuals committed to the rehabilitation after first traumatic SCI who received routine monitoring with duplex scan for higher risk of deep vein thrombosis may benefit from duplex screening.5 Another research found that ultrasound can identify changes in the morphology of hand muscles in people with cervical SCI.6 Thus, an ultrasound imaging methodology for quantifying the effects of cervical SCI on hand muscle morphology has been established.6 Ultrafast contrast-enhanced ultrasound (CEUS) Doppler is a technology created by a group of scientists which mixes CEUS with ultrafast plane-wave scans and has been used to image the in vivo spinal cord.7 This novel ultrafast CEUS Doppler was proven to evaluate the stability of spinal cord arteries and delineate hypoperfused spinal cord areas in a mouse traumatic SCI model.7 This technique can be a new preclinical and clinical biomarker, revealing real-time hemodynamic alterations in the spinal cord tissue. In the current era of spinal neurorehabilitation, many developments focus on enhancing neurological recovery; thus, the benefits of spinal ultrasound will be beneficial because of our greater understanding of the pathophysiology of SCI. Indeed, one of the significant limitations that Hwang BY et al did not mention is the lack of a feedback mechanism. To elucidate the concept of “feedback mechanism,” individuals with an incomplete spinal injury would have some residual ability to move certain specific muscles of their body that have been affected by SCI.8 The idea of such equipment for trying to facilitate spinal cord recovery and help individuals adapt to the limitations would be something that could sense the feedback and their ability to move 1 particular area of their body. Well, most of the devices out today or developed today do not have that feedback mechanism. We believe that a greater knowledge of the feedback process will lead to more effective and personalized treatments, which will improve neurorehabilitation results after SCI.