What are the indications for Transcranial Doppler (TCD) or other arterial testing in patients with Traumatic Brain Injury (TBI)?

From the Guidelines

For patients with suspected intracranial arterial injury, CTA Head and Neck is the recommended initial imaging evaluation due to its high accuracy, speed, and fewer safety concerns compared to catheter angiography. The development of modern CT equipment has allowed CTA to become the standard in diagnosis of suspected cerebrovascular injury, with reported sensitivities up to 100% 1. CTA is most useful in the initial imaging evaluation of suspected intracranial arterial injury, and its accuracy has been shown to be comparable to catheter angiography with modern CT equipment 1.

Some key points to consider when using CTA for arterial testing include:

• The Biffl grading scale for arterial injury can be used to classify the severity of injury, with grades ranging from I to V 1
• Medical therapy with antiplatelet or anticoagulation may be appropriate management for lower grades of arterial injury, whereas higher grades are more likely to require endovascular or surgical treatment 1
• CTA has been shown to have a sensitivity of 97.7% and a specificity of 100% for the diagnosis of vascular injury in trauma patients 1

In terms of performing CTA, it is essential to use modern CT equipment, such as >8-slice multidetector-row CT, to ensure high accuracy 1. The radiologist's expertise also plays a crucial role in interpreting the results of CTA 1. Overall, CTA Head and Neck is a reliable and efficient imaging modality for evaluating suspected intracranial arterial injury, and its use can help guide treatment decisions and improve patient outcomes.

From the Research

TBI Arterial Testing

• The diagnosis and management of Traumatic Brain Injury (TBI) often involve various imaging modalities, including CT angiography (CTA) and CT perfusion (CTP) imaging 2.
• CTA and CTP imaging can help identify cerebral perfusion abnormalities, such as vasospasm and hypoperfusion, which are common complications of TBI 2.
• The use of combined CTA and CTP imaging can facilitate monitoring of perfusion abnormalities and guide treatment decisions in TBI patients 2.
• Other imaging modalities, such as MRI, can also be used to detect certain intracranial injuries, such as axonal injuries, and blood products 24-48 hours after injury 3.
• The choice of imaging modality depends on various factors, including the severity of the injury, the presence of intracranial pathologic conditions, and the clinical presentation of the patient 3.

Imaging Modalities

• CT is the mainstay of imaging of acute TBI for both initial triage and follow-up, as it is fast and accurate in detecting both primary and secondary injuries that require neurosurgical intervention 3.
• MRI is more sensitive for the detection of certain intracranial injuries, but it has limitations, such as speed, accessibility, sensitivity to motion, and cost 3.
• The evidence primarily supports the use of MRI when CT findings are normal and there are persistent unexplained neurologic findings or at subacute and chronic periods 3.

Management of TBI

• Effective early management of moderate-to-severe TBI is essential to prevent secondary damage and improve patient outcomes 4.
• Key areas addressed in TBI management include the identification and classification of severe TBI, intubation strategies, and optimized resuscitation targets to maintain cerebral perfusion 4.
• The management of coagulopathy and special considerations for patients with concomitant hemorrhagic shock are also important aspects of TBI care 4.