ACCURATE CONTIGUOUS SECTIONS WITHOUT BREATH-HOLDING ON CHEST CT - VALUE OF RESPIRATORY GATING AND ULTRAFAST CT

OBJECTIVE, To image truly contiguous CT sections without breath-holding, we developed a respiratory-gating device combined with ultrafast CT The purpose of this study was to evaluate the utility of this system, especially focusing on the contiguity of the images. SUBJECTS AND METHODS, In 37 patients, we obtained respiratory-gated scans and breath-hold scans with 6-mm collimation and 6-mm incrementation (19 patients) and with 3-mm collimation and 3-mm incrementation (18 patients). We compared these two sets of images with respect to quality and contiguity. In nine patients who could not hold their breath because of dyspnea or infancy, we obtained only respiratory-gated scans with 3-mm collimation and 3-mm incrementation. Our respiratory-gating device was composed of a commercial ECG and respiratory monitor, a triggering device, an original amplifier, and an original switching unit. It was designed to control the scan timing of an ultrafast CT scanner at a user-selected level of the respiratory curve obtained with transthoracic impedance plethysmography.