From the Guidelines
The best initial view for diagnosing a rib fracture in the anterior left chest on X-ray is a standard posteroanterior (PA) chest radiograph, as recommended by the American College of Radiology 1. This view is preferred because it provides a comprehensive assessment of the chest and can detect complications such as pneumothorax, hemothorax, flail chest, or contusion, which are more important than the rib fractures themselves. Although the PA view may miss up to 50% of rib fractures, studies have shown that failure to detect fractures does not necessarily alter patient management or outcome in uncomplicated cases 1.
In addition to the PA view, an oblique view, specifically a left anterior oblique (LAO) projection, may be helpful in visualizing anterior rib fractures, which can be difficult to see on standard PA and lateral projections due to overlapping structures and the curvature of the ribs. However, the evidence does not strongly support the use of oblique views as the primary diagnostic tool for rib fractures.
It is also important to note that dual-energy chest radiography with bone subtraction imaging has not been shown to improve detection of rib fractures compared to standard radiographs 1. If a fracture is still suspected after conventional radiography but not definitively identified, a CT scan would be the next appropriate imaging study, as it offers superior sensitivity for detecting rib fractures, especially those in anatomically challenging locations 1.
Key points to consider when diagnosing rib fractures include:
- The presence and number of rib fractures, and the degree of displacement of the fractures, may carry prognostic significance 1.
- Rib fractures are associated with pulmonary complications, including atelectasis, impaired clearance of secretions, pneumonia, and adult respiratory distress syndrome 1.
- Increased number of rib fractures has been shown to directly correlate with increasing morbidity and mortality, particularly in patients 65 years or older 1.
From the Research
Best View for Diagnosing Rib Fracture in the Anterior Left Chest on X-ray
- The best view for diagnosing a rib fracture in the anterior left chest on X-ray is the 45° antero-posterior oblique projection performed on expiration, as recommended by a study published in the Polish journal of radiology 2.
- This view is particularly useful for evaluating lower rib fractures.
- For suspected upper rib fractures, a 45° oblique view during fast breathing is recommended 2.
- It's worth noting that chest X-ray (CXR) may miss up to 75% of rib fractures, and chest computed tomography (CT) is more sensitive in diagnosing rib fractures 3.
- Ultrasound examination can also be an effective tool in detecting rib fractures, especially in patients with no detected fractures on radiography 4, 5.
- The location and number of rib fractures can be important factors in predicting respiratory failure and mortality, and CT scanning can provide more accurate information on these factors than CXR 6.