PULMONARY NODULES IN SPIRAL VOLUMETRIC AND SINGLE SLICE COMPUTED-TOMOGRAPHY

Single slice acquisition of conventional CT and volume scanning of spi ral volumetric CT are compared in terms of detection and assessment of pulmonary nodules. Spiral CT is supposed to be superior to convention al CT in detecting all lung nodules by scanning the complete lung volu me, while conventional CT may miss nodules due to inconsistent levels of inspiration for single slices. Different technical procedures of sp iral CT may change the imaging of nodules and other findings. Fifty-tw o patients with known or suspected lung nodules were examined by conve ntional CT and spiral CT. Number and size of lung nodules and imaging of other pulmonary findings were registered independently by two radio logists. Spiral CT showed 15 lung nodules not seen on conventional CT, and missed one nodule. Spiral CT imaging of nodules was superior in s ome cases (characterisation of benign nodules) because complete scanni ng provided more information than conventional CT. It was worse in som e cases (small nodules, fibrosis, small pleural effusion) due to the g reater partial volume effect and less mAs. Technically improved spiral CT with longer scanning facilities and a 180-degree algorithm may be able to replace conventional CT for this indication.