3-DIMENSIONAL RECONSTRUCTION OF HUMAN DIAPHRAGM WITH THE USE OF SPIRAL COMPUTED-TOMOGRAPHY

We developed a technique of diaphragm imaging by using spiral computed tomography, and we studied four normal subjects who had been previous ly investigated with magnetic resonance imaging (A. P. Gauthier, S. Ve rbanck, M. Estenne, C. Segebarth, P. T. Macklem, and M. Paiva. J. Appl . Physiol. 76: 495-506, 1994). One acquisition of 15- to 25-s duration was performed at residual volume, functional residual capacity, funct ional residual capacity plus one-half inspiratory capacity, and total lung capacity with the subject holding his breath and relaxing. From t hese acquisitions, 20 coronal and 30 sagittal images were reconstructe d at each lung volume; on each image, diaphragm contour in the zone of apposition and in the dome was digitized with the software Osiris, an d the digitized silhouettes were used for three-dimensional reconstruc tion with Matlab. Values of length and surface area for the diaphragm, the dome, and the zone of apposition were very similar to those obtai ned with magnetic resonance imaging. We conclude that satisfactory thr ee-dimensional reconstruction of the in vivo diaphragm may be obtained with spiral computed tomography, allowing accurate measurements of mu scle length, surface area, and shape.