Multislice Computed Tomography of the Lung Parenchyma

Abstract

Computed tomography (CT) is still the most important imaging technique for diseases of the lung parenchyma. Spiral CT has taken this technique form a mere cross-sectional modality to a volumetric imaging tool and has markedly improved the detection of small pulmonary nodules, the staging of lung tumors, and the evaluation of the tracheobronchial system. Multi-planar reformations (MPRs) that were able to demonstrate the longitudinal extent of disease and allow for sections that could be individually adapted to pathology became possible. However, these reformations suffered from a limited spatial resolution if the spiral scan had to cover the whole chest. Alternatively, spiral CT provided high-resolution images but at the cost of a substantially reduced scan coverage. High-resolution CT (HRCT) and spiral CT remained reserved for distinctly different indications (apart from some fringe applications). Thus, evaluation of focal and diffuse lung disease in the same patient required two separate scan protocols to be performed after each other.