Non-invasive imaging modalities are crucial for clinicians and researchers to observe changes in organ/tissue structure, size, and integrity. Medical ultrasound (US) is widely used for clinical investigations and has a number of benefits. Compared with other non-invasive, tomographic modalities such as computed tomography (CT) and magnetic resonance imaging (MRI), US scanning is more rapid and much more economical. Unlike CT, US does not utilize ionizing radiation and unlike MRI there are no absolute contraindications. Patients with implanted devices, which may cause image degradation on other modalities, can typically be readily imaged with US. In general, even the most difficult of patients tolerate ultrasound well. Furthermore, ultrasound can readily provide information on blood flow without exogenous contrast administration. Despite all of the well-known benefits of US, imaging resolution on clinical systems has been an issue for a number of decades. Using the highest available linear transducers (typically up to 18MHz), the best resolution that could be achieved was around ~0.6mm or 600 m (characteristic resolution), which is comparable to clinical MRI. Although ultra high-resolution ultrasound systems have been available for a number of years, they have all been used for pre-clinical applications, such as on mice, rats, and rabbits. However, in April 2016, the U.S. Food and Drug Administration (FDA) cleared the first and only ultra high-frequency clinical ultrasound system for human use (Vevo MD, FUJIFILM, VisualSonics). With transducers as high as 70 MHz, characteristic resolution approaches 30 m, which is less than half the size of a grain of sand and 20 times better than existing clinical ultrasound machines. The Vevo MD system is the result of decades of experience gained on animals using preclinical systems, delivered to the bedside as an FDA-cleared device. With this system we can now non-invasively visualize human anatomy in a manner not previously possible. The Vevo MD is particularly useful for musculoskeletal imaging applications where many targets are relatively superficial to the skin surface. This includes certain locations of tendons (Drs. Chang and Murphy, Achilles and rotator cuff tendons), peripheral nerves (Dr. Shah, median, ulnar, and digital nerves), muscles (Dr. Rajasekaran, pelvic floor muscles and sphincters), and cartilage (Drs. Lee, Terkeltaub, and Liu-Bryan, femoral trochlea and digital cartilage). In addition, using this system, imaging of the anterior eye (Dr. Lee) and small crystals (Drs. Terkeltaub and Liu-Bryan) can be performed in vivo with unmatched resolution and speed. 1
Musculoskeletal dysfunction and pain is incredibly common in the Veteran population. Cartilage, muscle/tendon, and peripheral nerve diseases and injuries related to trauma, overuse and systemic diseases such as diabetes and obesity are of particular concern. Non-invasive imaging of the musculoskeletal system can be provided by a variety of modalities, including ultrasound. However, conventional clinical ultrasound systems using the highest available linear transducers yields resolutions of approximately 600 m. The new Vevo MD system is the first and only FDA-cleared ultra high-resolution ultrasound machine, which provides non-invasive, instantaneous imaging with characteristic resolutions approaching 30 m (less than half the size of a grain of sand and 20 times better than existing clinical ultrasound machines). This system will allow our researchers, including those studying musculoskeletal, ophthalmologic, and dermatologic diseases, access to unmatched resolution for structural and functional investigations to ultimately improve Veteran care. 1
