Quantitative Medical Imaging Approaches to Diagnosing Neuromuscular Injury and Tracking Repair
Abstract
What Is the Applicability of this Research? What is nerve injury? Nerves are tissues that conduct electrical signals from the brain and spinal cord to and from muscles in our arms and legs (motor function) and also let us sense the world around us (sensory function). Though nerves are often thought of as bundles of wires, they are actually a complex tissue composed of neurons (the main electrical cells), blood vessels (which provide oxygen and energy to neurons), and a variety of protective structural elements. Peripheral nerve damage is a devastating consequence of trauma to the limbs, ranging from blast injury caused by improvised explosive devices (IEDs) in theaters of war to vehicular accidents, gunshot wounds, or lacerations at home. Nerves may be damaged in isolation, or along with other surrounding tissues such as bone and muscle, in what is known as polytrauma. Among the problems associated with nerve damage are impaired movement and increased pain resulting in an inability to perform essential daily activities. Sadly, the degree of functional recovery from nerve damage is typically poor, particularly for nerves that experience a full or partial laceration (severing). Thus, improved methods to treat nerve injury are essential. What Are Key Challenges in Treating Nerve Injury? There is currently a lack of effective methods to medically image peripheral nerves. This is in large part because of the complexity of nerves and the fact that many nerve structures are hidden to many imaging approaches. Two critical clinical consequences of our inability to image nerves are (1) poor guidance on whether and how surgery should be performed on injured nerves (which depends on an accurate assessment of the quality and composition of injured nerves) and (2) an inability to reliably assess the success of nerve repair at early time points (which predicts longer-term recovery with more accuracy). What Is the Purpose of the Proposed Study? What Will Be Done? Our project addresses two Focus Areas prioritized by this grant mechanism: (1) solutions that accurately diagnose neuromusculoskeletal injuries in training and operational environments to optimize management and treatment decisions and (2) objective support tools to enable providers to assess function and performance throughout treatment and predict long-term outcomes. To address these Focus Areas, we propose the use of two powerful and clinically feasible strategies to image nerves: ultrasound, or US, and magnetic resonance imaging, or MRI. In particular, we propose to use variations on US and MRI called "quantitative US" (qUS) and "quantitative MRI" (qMRI). Unlike conventional US and MRI, these approaches can provide objective (that is, unbiased) measurements of the biological and structural changes within a nerve with high resolution and accuracy. We will first deploy qUS and qMRI methods in rat models of nerve injury and repair (Aim 1). This will allow us to control the severity of injury and also make invasive measurements of structure and function that we cannot make in humans. We will then deploy our methods in patients who have suffered nerve injuries of different severity. We hypothesize that quantitative imaging outcomes will provide new, powerful, and non-invasive descriptions of structural and biological properties of injured nerves that cannot currently be assessed in humans. What Is the Clinical Benefit to Military and Veteran Populations? Modern ballistic helmets and body armor provide improved protection to the head and torso against traumatic blast injuries, such as those caused by IEDs. However, because these regions of the body are better protected, the limbs of surviving Soldiers experience a very large number of injuries. Peripheral nerves are especially vulnerable to blast injury. Traumatic nerve injuries account for between 1-4% of all injuries in the armed forces, and injured personnel often experience nerve damage
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 10, 2021
- Source ID
- W81XWH2010927
Entities
People
- Sameer B Shah
Organizations
- United States Army
- Veterans Medical Research Foundation of San Diego