From the Guidelines
The best radiological test for diagnosing a nasal fracture is a CT scan, specifically a CT Maxillofacial, as it offers superb delineation of osseous and soft-tissue structures and is more sensitive in confirming the clinical suspicion of nasal bone fracture compared to radiographs 1. When considering the diagnosis of a nasal fracture, it's essential to weigh the benefits and limitations of various imaging modalities.
- CT scans provide high image resolution with thin-section acquisitions, allowing for the detection of subtle nondisplaced fractures of the facial skeleton.
- They also offer multiplanar and 3-D image reconstructions, which are critical in preoperative planning for complex nasal injuries and associated facial fractures 1.
- In contrast, plain radiographs have limited diagnostic value in the evaluation of nasal trauma, with a diagnostic accuracy ranging from 53% to 82% 1.
- Ultrasound (US) has shown promise in detecting nasal fractures, with high sensitivity and specificity, but it is not typically the first-line imaging test for evaluation of nasal injuries 1.
- The decision to obtain imaging should be based on clinical presentation, as not all nasal fractures require radiological confirmation before treatment, especially when the diagnosis is clear from physical examination and the treatment plan would remain unchanged regardless of imaging findings.
- However, in cases where complex facial trauma is suspected or plain radiographs are inconclusive, a CT scan is the preferred imaging modality due to its superior detail and ability to detect associated injuries to adjacent facial structures 1.
From the Research
Radiological Tests for Nasal Fracture
The best radiological test for diagnosing a nasal fracture can be determined by evaluating the sensitivity, specificity, and accuracy of various imaging modalities.
- Computed Tomography (CT) scans have been shown to have high sensitivity and specificity in detecting nasal bone fractures, with an accuracy of 94.4% 2.
- Ultrasonography (USG) is also a reliable method for diagnosing nasal bone fractures, with an accuracy of 85.0% 2.
- Plain film radiography, including lateral and Waters' views, has a lower accuracy of 67.7% compared to CT and USG 2.
Comparison of Imaging Modalities
A systematic review comparing the diagnostic performance of plain film, ultrasonography, and computed tomography in nasal bone fractures found that:
- CT had the highest accuracy, followed by USG, and then plain film 2.
- USG had higher sensitivity and specificity than plain film, but lower than CT 2.
- The combination of lateral and Waters' views had higher accuracy than either view alone 2.
Specific Studies
- A study published in 2012 found that conductor-assisted nasal sonography (CANS) had 100% sensitivity and 89% specificity in detecting nasal bone fractures, outperforming conventional methods 3.
- A study published in 2011 found that high-resolution ultrasonography (HRUS) had a sensitivity of 97% and specificity of 100% in detecting nasal bone fractures, comparable to CT scans 4.
- A study published in 2016 found that ultrasonography had higher specificity and positive predictive value than CT in detecting midline fractures of the nasal bone 5.
- A study published in 2006 found that CT scans were necessary for diagnosing nasal bone fractures, as plain film radiographs had a reliability of only 82% 6.