New imaging recommendations included in updated TBI assessment criteria
Imaging will play a prominent role in a new framework recently developed to better diagnose the severity of brain injuries.
Traditionally, the Glasgow Coma Scale (GCS) sum score is used to measure TBI severity, but research published in recent years has indicated that these scores aren’t thorough enough and may leave vulnerable patients in need of further treatment behind. What’s more, using GCS scores alone to gauge TBI severity could result in family members choosing to withdraw life support for their loved ones when additional therapies and treatment options might have enabled the patients to go on to recover in due time.
“There are patients diagnosed with concussion whose symptoms are dismissed and receive no follow-up because it’s ‘only’ concussion, and they go on to live with debilitating symptoms that destroy their quality of life,” corresponding author Geoffrey Manley, MD, PhD, professor of neurosurgery at UC San Francisco and a member of the UCSF Weill Institute for Neurosciences, said in a UCSF release. "On the other hand, there are patients diagnosed with 'severe TBI' who were eventually able to live full lives after their families were asked to consider removing life-sustaining treatment."
In 2022 the National Institute of Health (NIH)- National Institute of Neurological Disorders and Stroke launched an initiative to address the unmet need for better TBI characterization. Experts and patients who have experienced traumatic brain injuries from 14 countries collaborated to create a more thorough framework, which aims to give providers a more comprehensive picture of how to manage TBI.
Together, the experts developed a new framework that incorporates four pillars—clinical (full GCS and pupillary reactivity), biomarker pillar (blood-based measures), imaging (pathoanatomical measures) and a modifier (features influencing clinical presentation and outcome), or CBI-M for short.
The imaging portion focuses largely on CT, which is the most common modality used to assess acute TBI, while experts recommend using MRI for the post-acute and chronic phase of monitoring. Imaging biomarkers identified during prior research remain an integral aspect of measuring TBI severity, but new descriptors—traumatic axonal or microvascular injury (both can co-occur)—have been added to the criteria.
“The term traumatic axonal or microvascular injury was proposed by the imaging working group to replace traumatic axonal injury and diffuse axonal injury, which are typically seen on acute CT or MRI scans,” the group explained. “This change in nomenclature is based on the finding that axonal and microvascular lesions often occur in the same locations, and might be difficult or impossible to distinguish on an acute brain CT scan.”
Another addition to the imaging aspect is the recommendation to document and describe lesions with a total volume of 25 mL or more, CT signs of mass effect and other chronic or incidental lesions.
Currently, these pillars remain recommendations, rather than standardized criteria. The group acknowledged that its implementation could present challenges, especially in resource-strapped areas. However, they are optimistic that it could improve TBI outcomes in the future once further validated.
“We do not present this framework as a finished product,” the group noted. “The framework will require refinement and validation in large contemporary studies before being considered for implementation into general clinical practice. This validation is ongoing, with some preliminary results being reported that show strong correlations of injury-related components with CBI-M pillars.”
To view the full set of recommendations, click here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.