Chest CT Use in Pectus Excavatum
Primary Recommendation
Chest CT is recommended for preoperative planning in pectus excavatum when surgical correction is being considered, primarily to calculate the Haller index (pectus severity index), but chest radiography alone may be sufficient for initial assessment in asymptomatic patients. 1, 2
Initial Imaging Approach
Chest radiography should be the first-line imaging modality for patients with pectus excavatum, as it can identify clinically important findings including cardiac displacement, depth of sternal depression, and associated abnormalities. 3, 4
The Haller index can be measured on chest radiographs with excellent correlation to CT measurements (Pearson correlation 0.984), making chest X-ray a viable alternative to CT in asymptomatic patients. 4
Chest radiography substantially reduces radiation exposure compared to CT while still providing adequate diagnostic information for initial evaluation. 3, 4
When CT is Indicated
Preoperative Planning
CT chest with or without IV contrast is appropriate when surgical correction is planned, as it provides precise anatomic measurements necessary for operative planning. 1, 2
CT is particularly valuable for defining the orientation of ribs and costal cartilages and their relationship to the sternum, allowing exact preoperative measurement of the bony rib cage. 5
MRI can facilitate surgical chest wall reconstruction planning and is particularly useful for pectus excavatum diagnosis and management when avoiding radiation is desired. 1, 2
Specific Clinical Scenarios
CT is indicated when evaluating for associated cardiac compression or displacement, especially when kyphoscoliosis is present, as cardiac migration to the left hemithorax may occur. 2
Spiral CT with 3D reconstruction is valuable in patients requiring reoperation for failure of chest wall growth after previous pectus excavatum surgery, as it defines complex anatomic relationships. 5
CT with IV contrast provides detailed anatomic assessment when surgical planning requires precise measurements, particularly for complex cases. 2
Comprehensive Preoperative Evaluation
Beyond imaging, the complete preoperative workup should include:
Pulmonary function testing to assess for restrictive disease patterns. 6
Echocardiography to evaluate for mitral valve prolapse (present in approximately 15% of patients), diminished right ventricular volume, and right ventricular compression. 6, 7
Complete cardiac evaluation is mandatory when genetic syndromes are suspected (Marfan, Noonan, connective tissue disorders), as pectus excavatum may be a phenotypic feature requiring comprehensive cardiac workup. 2, 6
Key Clinical Pitfalls
Avoid routine chest CT solely for Haller index measurement in asymptomatic patients when chest radiography can provide comparable measurements with significantly less radiation exposure. 3, 4
In patients with connective tissue syndromes, failure to perform comprehensive cardiac evaluation may miss associated mitral valve prolapse or other cardiac pathology. 2, 6
Standard echocardiographic views may be limited by the abnormal anterior chest wall anatomy; modified views including apical four-chamber views are necessary to visualize extrinsic compression of the right ventricle. 7
When chest CT is performed, a limited CT technique focused on obtaining the Haller index is preferable to full chest CT to minimize radiation exposure, unless additional clinical concerns warrant comprehensive imaging. 3