What is the indication for a computed tomography (CT) scan of the abdomen and pelvis in a patient with lumbar spine tenderness following trauma?

From the Guidelines

A CT scan of the abdomen and pelvis is generally not the first-line imaging choice for evaluating isolated lumbar spine tenderness in trauma patients. Instead, plain X-rays of the lumbar spine should be performed initially to assess for fractures or alignment issues. If the patient has concerning findings on physical exam (such as neurological deficits), persistent severe pain, or high-energy trauma mechanism, then advanced imaging may be warranted. In these cases, a non-contrast CT of the lumbar spine specifically (not the entire abdomen and pelvis) would be more appropriate for evaluating bony injuries. MRI would be preferred if there is concern for ligamentous injury, disc herniation, or spinal cord/nerve root compression. The rationale for this approach is that CT of the abdomen and pelvis exposes the patient to significant radiation while not optimally visualizing the spinal structures, as noted in studies such as 1.

It's also important to consider that patients with lumbar spine tenderness after trauma should be evaluated comprehensively, including a thorough neurological examination, to guide appropriate imaging decisions and ensure no serious injuries are missed. The use of CT scans in trauma patients is supported by guidelines such as those from the American College of Radiology, as seen in 1 and 1, which emphasize the importance of CT scans in evaluating patients with penetrating torso trauma. However, these guidelines do not specifically address the evaluation of isolated lumbar spine tenderness, and therefore, a more targeted approach using plain X-rays and non-contrast CT of the lumbar spine is recommended.

Some may argue that CT scans of the abdomen and pelvis are necessary to evaluate for other potential injuries, but this approach is not supported by the evidence, as noted in 1 and 1, which suggest that dedicated CT scans of the lumbar spine are more appropriate for evaluating bony injuries. Additionally, the use of MRI is preferred if there is concern for ligamentous injury, disc herniation, or spinal cord/nerve root compression, as it provides more detailed imaging of these structures, as noted in 1.

In summary, the initial evaluation of isolated lumbar spine tenderness in trauma patients should include plain X-rays of the lumbar spine, followed by advanced imaging such as non-contrast CT of the lumbar spine or MRI if necessary, rather than a CT scan of the abdomen and pelvis. This approach is supported by the evidence and prioritizes the patient's safety and well-being by minimizing radiation exposure and optimizing imaging of the spinal structures. Key points to consider include:

• Initial evaluation with plain X-rays of the lumbar spine
• Use of non-contrast CT of the lumbar spine for advanced imaging
• Preference for MRI if concern for ligamentous injury, disc herniation, or spinal cord/nerve root compression
• Minimizing radiation exposure by avoiding unnecessary CT scans of the abdomen and pelvis.

From the Research

Imaging Protocols for Lumbar Spine Tenderness in Trauma

• The use of CT scans in evaluating spinal trauma, including lumbar spine tenderness, is a common practice 2, 3.
• A study published in 2009 compared routine versus selective computed tomography of the abdomen, pelvis, and lumbar spine in blunt trauma, and found that routine CT revealed additional traumatic injuries in 15% of patients in the abdomen, 2.4% in the pelvis, and 8.2% in the lumbar spine 3.
• The Spinal Cord Society recommends the use of CT without contrast as the initial line of imaging for cervical and thoracolumbar spine trauma patients, and suggests that CT screening in polytrauma cases can be done with a multidetector CT by utilizing reformatted images obtained when scanning the chest, abdomen, and pelvis (CT-CAP) 2.

Role of MRI in Spinal Trauma

• Magnetic resonance imaging (MRI) has been playing an increasingly important role in spinal trauma patients due to its high sensitivity for detection of acute soft tissue and cord injuries 4.
• MRI is indicated in cases with neurological involvement and advanced cervical degenerative changes, and to determine the extent of soft tissue injury, such as disco-ligamentous injuries and epidural space compromise 2, 4.

CT Scout Images and Reformatted Images

• A study published in 2007 found that CT scout images can accurately evaluate the thoracolumbar spine after blunt trauma, with a sensitivity of 92% and specificity of 100% 5.
• Another study published in 2015 found that reformatted images of the thoracic and lumbar spine following CT of chest, abdomen, and pelvis in the setting of blunt trauma can detect additional fractures and alter patient management in some cases 6.