[Progress in tomodensitometry. Applications in cancerology]

Since 1992, spiral CT scanners replace conventional CT units in radiology departments. In the first part of this paper, we present some technical considerations concerning spiral CT (continuous rotation and emission of the source-detector; continuous translation of the patient at a constant rate through the gantry), as well as advantages and limitations of volumic acquisition. The main advantages can be summerized as: reduction of the acquisition time, optimization of contrast enhancement with intravenous opacification, and post processing allowing retrospective creation of overlapping images, multiplanar reconstructions, and 3-D reconstructions. Spiral CT improves lesions detection and characterization. Disadvantages are due to contrast media injection and radiation exposure. Then we describe clinical applications in the carcinologic field concerning pharyngo-laryngeal tumors, bronchogenic carcinoma, mediastinal tumors, pulmonary nodules, sub-diaphragmatic tumors. However, tumors of brain, spine, bone, and soft tissue are better explorated with MRI. Authors conclude on the future improvements of spiral CT.