From the Guidelines
The best protocol for imaging ribs is a dedicated rib radiograph series, which typically includes oblique views and posteroanterior (PA) chest radiographs, as it is usually sufficient for the diagnosis of rib fractures and detection of complications such as pneumothorax, hemothorax, or flail chest 1. For more detailed evaluation, computed tomography (CT) without contrast is recommended as it offers superior sensitivity for detecting rib fractures and associated complications, and should be performed with thin-slice (1-3mm) acquisition using both bone and soft tissue reconstruction algorithms 1. In cases where there is suspicion of bone metastases or infection, magnetic resonance imaging (MRI) may be valuable as a complementary study. Ultrasound can be useful for pediatric patients or pregnant women to minimize radiation exposure, particularly for anterior rib fractures. Nuclear medicine bone scans may detect occult fractures not visible on conventional imaging but are less commonly used as first-line studies. The choice of imaging modality depends on clinical context, with radiographs being appropriate for initial screening due to lower radiation dose and cost, while CT is preferred when higher sensitivity is required for trauma cases or when complications are suspected. Some key points to consider when choosing an imaging modality include:
- The patient's clinical presentation and history, including the mechanism of injury and presence of symptoms such as chest pain or shortness of breath
- The presence of associated injuries or complications, such as pneumothorax or hemothorax
- The patient's age and underlying medical conditions, which may affect their ability to undergo certain imaging studies or increase their risk of complications
- The availability and quality of imaging equipment and personnel, which can impact the accuracy and reliability of the imaging study. It is also important to note that the American College of Radiology Appropriateness Criteria recommend that a radiograph of the chest is usually appropriate for the initial imaging of suspected rib fractures from minor blunt trauma, and that CT chest without IV contrast or Tc-99m bone scan whole body may be complementary to the chest radiography in certain cases 1. Overall, the choice of imaging modality for rib fractures should be based on a careful consideration of the patient's individual needs and circumstances, as well as the availability and quality of imaging equipment and personnel.
From the Research
Imaging Protocols for Ribs
The best protocol for imaging ribs involves various radiographic projections and techniques.
- Conventional frontal radiography is often used as the initial imaging modality for detecting rib fractures, but it may not always be sufficient due to limitations such as alignment of bone fragments or projection difficulties 2.
- Ultrasonography (US) can be a useful complement to frontal radiographs, especially in cases where radiography is negative or inconclusive 2, 3.
- US examination has been shown to detect rib fractures missed by radiography, particularly in patients without detected fractures on radiography 3.
- However, another study found that US does not significantly increase the detection rate of rib fractures and may be too time-consuming for routine use 4.
- Various radiographic projections, such as oblique views at 45° or 30° angles, can be used to improve the detection of rib fractures 5.
- The 45° antero-posterior oblique projection performed on expiration is recommended for diagnostics and interpretation of traumatic rib fractures, while the 45° oblique view during fast breathing is recommended for suspected upper rib fractures 5.
- Knowledge of normal rib anatomy and variants is essential for accurate interpretation of radiologic images and prevention of misdiagnosis 6.