CTthorax

A CT thorax, or chest computed tomography, is a diagnostic imaging modality that uses X-ray beams and a rotating gantry with detectors to produce cross-sectional images of the thoracic structures. Modern scanners can acquire detailed images rapidly and can be performed with or without intravenous iodinated contrast. The study is reconstructed into axial slices and can be reformatted into multiple planes and three-dimensional renderings as needed.

Indications for CT of the chest include acute chest pain with suspicion of pulmonary embolism, infectious processes such as pneumonia, pleural effusion or empyema, trauma evaluation, evaluation of thoracic masses and nodules, mediastinal pathology, lymphadenopathy, and cancer staging. Protocols vary and may include non-contrast CT for calcifications, high-resolution CT (HRCT) for interstitial lung disease, CT pulmonary angiography (CTPA) for PE, and chest CT with IV contrast for mediastinal evaluation.

Procedure and contrast: patients lie supine and perform breath-holds to minimize motion. An iodinated contrast agent is often administered intravenously unless contraindicated. Pre-scan assessment includes allergy history and renal function. CT angiography uses specific timing and bolus tracking. Radiation dose is minimized through optimized protocols and shielding where appropriate.

Interpretation and findings: radiologists assess the lungs, airways, vasculature, mediastinum, pleura, and bones. Common findings include pneumonia, pulmonary edema, pulmonary embolism, nodules or masses, pleural effusions, pneumothorax, and atelectasis, as well as interstitial or fibrotic changes. Many studies also reveal incidental findings.

Limitations and safety: motion artifacts, obesity, and certain implants can degrade image quality. Radiation exposure requires justification and dose optimization. Contrast-related risks include allergic reactions and nephrotoxicity, though these are mitigated by screening and hydration when feasible.