Diagnostic imaging of rib injuries

Radiographic examination

Radiography is the primary method for detecting bone injuries. When evaluating the ribs, a standard anteroposterior projection alone is insufficient.

• Mandatory projections: anteroposterior (AP) including the clavicles, and oblique projections of both hemithoraxes (specifically for visualizing the ribs).
• Pediatric considerations: skeletal survey (skeletal survey) must be performed by experienced radiographers under physician supervision. Taking a single whole-body overview radiograph ("babygram") is prohibited. High-quality radiographs of each anatomical region separately are required.
• Follow-up timing: up to 2/3 of fresh rib fractures may not be visible initially. Control radiographs at 11–14 days have high diagnostic value: by this time, a bone callus (callus) forms, and fracture lines become distinct. In some cases (e.g., thin/subtle fractures), the callus is visible as early as 1 week later.

Advanced imaging: CT, MRI, and scintigraphy

Although assessing bone structures is not the primary goal of chest radiography, their injuries require detailed evaluation.

• Computed tomography (CT): indicated for detailed characterization of bone lesions, complicated fractures, and assessment of remodeling (multidetector 2D and 3D reconstructions are particularly informative). Contrast-enhanced CT is indicated in all children with suspected chest trauma. CT is also indispensable if massive subcutaneous emphysema masks a pneumothorax on conventional radiographs.
• Bone scintigraphy: can be used when the radiograph is normal but there is high suspicion of abuse. The method uses pinhole collimators (pinhole). The advantage is high sensitivity for rib fractures in the first hours after trauma. The disadvantage is low sensitivity for old fractures.
• Magnetic resonance imaging (MRI): is not used routinely to assess bone injuries in infants, as it has low sensitivity for rib and metaphyseal fractures.

Accidental vs. non-accidental trauma (NAT)

Differential diagnosis of the causes of fractures is of critical importance, especially in pediatrics.

Accidental injuries:

• Peak incidence occurs at 10–14 years of age.
• In infants (infants), clavicle and skull fractures are more common, whereas in toddlers (toddlers), tibial shaft fractures predominate.
• Multiple fractures are atypical (only 16% of cases).

Non-accidental trauma (abuse):

• Diagnosed more frequently in children under 2 years of age.
• Multiple fractures occur in 74% of cases.
• The ribs are affected in approximately 25% of long bone and skull trauma cases.
• Red flags: rib fractures (especially of the posterior segments) in non-ambulatory infants. When fractures are identified in a child under 18 months of age, physical abuse should always be suspected.

Diagnostic pitfalls and complications

In the radiodiagnosis of rib injuries, one may encounter a number of artifacts and associated pathologies that alter the radiographic appearance.

1. Subcutaneous emphysema: air spreads along fascial planes, creating a pattern of linear lucencies (linear transradiancies). This can greatly complicate the diagnosis of pneumothorax.
2. Simulation of pulmonary pathology: a bone callus forming on a rib can mimic an intrapulmonary opacity (intrapulmonary opacity).
3. Effect on the diaphragm: pain syndrome from a rib fracture is one of the frequent causes of unilateral elevated position of the diaphragmatic dome.
4. Congenital anomalies: bifid (bifid), widened, or fused upper ribs can be mistaken for post-traumatic remodeling.
5. Rib notching (rib notching): is not a sign of fracture; most commonly caused by aortic coarctation or type I neurofibromatosis.

Class and exam questions

What else to study on this topic

• Quality criteria for skeletal radiographic examination (skeletal survey)
• Radiological signs of subcutaneous emphysema and pneumothorax
• Differential diagnosis of rib notching (aortic coarctation, neurofibromatosis)
• Causes of unilateral and bilateral elevation of the diaphragm
• Imaging algorithm in non-accidental injury (NAI) syndrome

Other Topics in "Pediatric Diagnostic Radiology"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.