Multislice CT of the Thorax: Opportunities, Challenges and Solutions

The scan speed of current generation multislice CT (MSCT) scanners with simultaneous acquisition of up to 16 slices translates into the ability to scan the entire chest in a breath-hold time of 10 s or less. Despite submillimeter resolution, this results in motion-free images even in the most critically ill patients. Use of thin slices was shown to significantly improve the detection of minute pathology, small lung nodules or visualization of peripheral pulmonary vessels. For a comprehensive diagnosis of focal and diffuse lung disease, both contiguous images and high-resolution CT can be reconstructed from the same single acquisition, without scanning the patient twice. ECG synchronization with MSCT is a valuable tool to improve image quality and diagnostic accuracy by reducing motion artefacts as potential sources of error. However, while MSCT provides innumerable opportunities, its unique characteristics also pose hitherto unknown challenges to its users. The large volume datasets generated by 4-, 10-, 16-, or more-slice MSCT are a logistical problem that threatens to overburden the radiologist with diagnostic information. Also, although MSCT can be used in ways which result in a reduction of patient radiation dose, with many applications the patient dose is likely to increase moderately. Solutions, however, are on the horizon: the practice of radiology is quickly adapting to novel concepts of data visualization embracing 2-D and 3-D visualization techniques. The performance of tools for the detection, visualization and characterization of lung lesions with MSCT is being continuously improved. Sophisticated means for reducing radiation dose are being implemented. In the following we discuss specific improvements, novel challenges and sophisticated solutions, which the advent of ever-faster MSCT acquisition techniques has brought about with a special focus on disease entities of great socioeconomic importance: imaging of focal lung disease and vascular imaging of the thoracic aorta and pulmonary circulation.