Pediatric Imaging

Which Imaging Study Is Best for Suspected CNS Injury in Abused Children Over 2?

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Which Imaging Study Is Best for Suspected CNS Injury in Abused Children Over 2?

A three-year-old is brought to the emergency department with a large, tender scalp hematoma and a new limp. The caregiver’s explanation for the injuries is inconsistent and changes upon re-questioning. While the child is irritable, their neurologic examination is nonfocal. You are concerned for non-accidental trauma and must determine the appropriate initial imaging to evaluate for a potential Central Nervous System (CNS) injury. This clinical decision point requires a careful balance between diagnostic yield, radiation exposure, and the urgency of potential findings. For this specific scenario, the American College of Radiology (ACR) Appropriateness Criteria rate Radiography of the area of interest as Usually Appropriate, providing a targeted first step in the diagnostic pathway.

Who Fits This Clinical Scenario?

This guidance applies specifically to children greater than 24 months of age for whom there is a clinical suspicion of physical abuse, and the presentation includes findings suggestive of CNS injury. This is the initial imaging workup.

Inclusion Criteria:

  • Age: 25 months and older.
  • Suspicion: Concern for physical abuse based on history, physical exam, or social context.
  • Clinical Findings: One or more signs pointing to potential head, neck, or spine injury. This includes neurologic signs or symptoms (e.g., altered mental status, seizures, focal deficits) or physical injuries like scalp bruises, hematomas, or other skin injuries to the head, neck, or spine.

Exclusion Criteria (These patients follow different guidelines):

  • Children 24 months or younger: This is a critical distinction. Infants and toddlers have a different injury epidemiology and a lower threshold for a full skeletal survey. Their evaluation is covered in a separate ACR variant.
  • Suspected Visceral Injury: A child presenting with abdominal bruising, tenderness, or distention requires a different imaging pathway focused on the abdomen and pelvis, often starting with lab work and potentially abdominal CT.
  • Unambiguous Accidental Trauma: If a clear, plausible, and high-energy accidental mechanism of injury fully accounts for all clinical findings, standard trauma protocols apply rather than this specific abuse-focused guideline.

What Diagnoses Are You Working Up in This Scenario?

The primary goal of initial imaging in this context is to identify acute, significant injuries that require immediate intervention and provide objective evidence of trauma. The differential diagnosis is focused on traumatic injuries that may not be apparent on physical examination alone.

Skull Fracture
This is a primary concern, especially with a focal scalp hematoma. A fracture provides definitive evidence of significant head impact. The type of fracture (linear, depressed, complex, crossing sutures) can also inform the likelihood of non-accidental versus accidental mechanisms. Radiography is highly effective at identifying skull fractures.

Intracranial Hemorrhage
This is the most life-threatening potential injury. Subdural hematomas are a classic finding in abusive head trauma, but epidural and subarachnoid hemorrhage can also occur. While radiography cannot directly visualize intracranial bleeding, the presence of a skull fracture dramatically increases the risk of an underlying hemorrhage and mandates further cross-sectional imaging.

Cervical Spine Injury
Though less common than intracranial injury in this setting, injury to the cervical spine can have devastating consequences. Suspicion should be high in children with neck bruising, torticollis, or neurologic deficits. Radiography serves as an effective initial screening tool for fractures or malalignment in a cooperative child.

Accidental Injury Mimics
Imaging helps characterize the injury pattern to assess for consistency with the provided history. The goal is to differentiate between an accidental fall, which might cause a simple linear parietal fracture, and the more complex or multiple injuries often seen in physical abuse. While imaging alone is rarely definitive for abuse, it is a critical piece of the multidisciplinary evaluation.

Why Radiography of the Area of Interest Is the Recommended Study for This Presentation

In a child over 24 months with a focal sign of head trauma (like a scalp hematoma) but no overt neurologic symptoms, targeted radiography is a logical and evidence-based first step. The ACR rates both Radiography area of interest and CT head without IV contrast as Usually Appropriate, and the choice often hinges on the specific clinical signs.

The rationale for starting with radiography in a neurologically intact child is rooted in its high utility for the most direct question: is there a skull fracture?

  • Diagnostic Value: Radiography is highly sensitive and specific for detecting skull fractures. A positive finding confirms significant trauma and provides a clear indication for the next step, which is almost always a head CT to assess for intracranial injury.
  • Resource and Time Efficiency: Radiographs are fast, widely available in nearly all emergency settings, and do not typically require sedation in a toddler or young child.
  • Radiation Dose: While not zero, the radiation dose from a skull radiograph series is significantly lower than that from a CT scan. The pediatric radiation dose for a CT head is rated ☢☢☢ (0.3-3 mSv), whereas radiography is variable but generally much lower for a localized area. This aligns with the As Low As Reasonably Achievable (ALARA) principle.

Why are other studies rated lower for this initial workup?

  • US head is rated Usually not appropriate. In children over 24 months, the anterior fontanelle is typically closed or too small to provide an adequate acoustic window, rendering ultrasound ineffective for evaluating the brain and skull.
  • MRI head without IV contrast is rated May be appropriate. MRI offers superior detail for soft tissue injury, non-hemorrhagic contusions, and diffuse axonal injury. However, it is not the ideal initial test in an acute setting. It is less available, takes significantly longer to perform, and often requires sedation or general anesthesia in this age group, which introduces its own risks and delays. MRI is more commonly used as a follow-up study to better characterize injuries found on CT or if neurologic concerns persist despite a negative CT.

If the child presents with clear neurologic signs or symptoms (e.g., seizure, altered mental status, focal deficit), the clinical question shifts from “Is there a fracture?” to “Is there an acute brain injury?” In that case, CT head without IV contrast becomes the more appropriate initial study, as it is the fastest and most effective modality for detecting acute intracranial hemorrhage that may require neurosurgical intervention.

What’s Next After Radiography of the Area of interest? Downstream Workflow

The results of the initial radiograph guide the subsequent diagnostic and clinical pathway. The workflow is designed to ensure that significant injuries are not missed while avoiding unnecessary imaging.

If the Radiograph is POSITIVE (e.g., shows a skull fracture):

  • Next Imaging Step: A positive skull radiograph mandates a CT head without IV contrast to evaluate for associated intracranial injuries, such as epidural or subdural hematomas. The fracture itself confirms a significant mechanism of injury, and the primary concern becomes the status of the brain.
  • Clinical Next Steps: The child requires hospital admission for neurologic monitoring. A full multidisciplinary evaluation for child abuse must be initiated, including consultation with child protective services and a child abuse specialist. A Radiography skeletal survey (May be appropriate) should be performed to screen for other occult fractures.

If the Radiograph is NEGATIVE, but clinical suspicion remains high:

  • Next Imaging Step: A negative radiograph does not rule out underlying brain injury. If the physical findings are significant (e.g., large, boggy hematoma) or if any neurologic symptoms develop, proceed to a CT head without IV contrast.
  • Clinical Next Steps: The threshold for admission and further evaluation should remain low. The decision for a skeletal survey depends on the overall clinical picture and the presence of other injuries.

If the Radiograph is NEGATIVE, and the injury is minor:

  • Next Steps: If the child is neurologically intact, the external injury is minor, and the social situation allows for safe discharge with reliable follow-up, a period of observation may be appropriate. Clear return precautions must be provided to the caregiver.

Pitfalls to Avoid (and When to Get Help)

Navigating a suspected child abuse case is clinically and emotionally challenging. Avoiding common diagnostic pitfalls is crucial for patient safety.

  • Stopping Too Soon: Do not let a negative skull radiograph provide false reassurance in a child with a significant scalp injury or a concerning history. Brain injury can exist without a fracture.
  • Ignoring Other Injuries: The focus on CNS injury should not preclude a thorough top-to-toe physical examination. The presence of bruises in different stages of healing, fractures elsewhere, or abdominal tenderness should trigger the appropriate parallel workups.
  • Attributing Findings to Accidental Trauma Prematurely: Certain injury patterns, such as complex or depressed skull fractures, posterior rib fractures, or metaphyseal corner fractures, have a high specificity for abuse. Maintain a high index of suspicion.
  • Delaying Consultation: These cases require a multidisciplinary team. Involve a child abuse pediatrician, social work, and child protective services early in the evaluation.

If you identify a skull fracture, intracranial hemorrhage, or any other injury highly suspicious for abuse, immediate escalation to a pediatric specialist and the appropriate hospital and state authorities is mandatory.

Related ACR Topics and Tools

For a comprehensive overview of imaging in all related scenarios, refer to the parent topic article. The tools below can assist in navigating adjacent criteria, understanding imaging protocols, and discussing radiation with families.

Frequently Asked Questions

Why is a skeletal survey only ‘May be appropriate’ in a child over 2 years old?

In children older than 24 months, the incidence of occult fractures from physical abuse is lower than in infants. The decision to perform a skeletal survey is based on the overall clinical picture, such as the presence of a confirmed fracture on initial imaging, multiple other injuries, or a high-risk social situation. It is not performed as a routine screening tool in every case for this age group, unlike in infants.

If the child has a seizure, should I still start with a radiograph?

No. A seizure is a significant neurologic symptom. In this case, you should bypass radiography and proceed directly to a CT head without IV contrast as the initial imaging study. CT is the fastest and most effective way to identify acute intracranial hemorrhage, which is a primary concern in a post-traumatic seizure.

Is there any role for MRI as the first imaging test in this scenario?

Rarely. While MRI is more sensitive for certain brain injuries, it is generally considered a second-line or problem-solving tool in the acute setting for this age group. Its long acquisition time, need for sedation, and limited availability make CT the preferred initial modality for assessing for life-threatening acute injury. MRI is typically reserved for follow-up or when neurologic findings are unexplained by CT.

Does a normal head CT rule out abusive head trauma?

No. A normal initial head CT is reassuring for the absence of acute, life-threatening hemorrhage, but it does not rule out abusive head trauma. Some injuries, like diffuse axonal injury or small non-hemorrhagic contusions, may not be visible on CT. Furthermore, the diagnosis of abuse is a clinical one, made by a multidisciplinary team based on the totality of evidence, not just a single imaging study.

When should I consider imaging the spine in a child over 2 with suspected abuse?

Spinal imaging should be considered if there are specific signs or symptoms pointing to a spinal injury. This includes neck or back pain/tenderness, torticollis, neurologic deficits (e.g., weakness, sensory changes, bowel/bladder dysfunction), or significant bruising over the spine. In these cases, radiography of the specific area of concern is the appropriate first step.

Reviewed by Pouyan Golshani, MD, Interventional Radiologist — May 30, 2026