[Development of a breath pacemaker for 2D-PACE respiratory gated MRCP: efficacy of image quality improvement]

Two-dimensional prospective acquisition correction (2D-PACE) is a human body motion-correction technique that uses the navigator echo sequence. Clinically, this respiratory-gated technique is used to improve the image quality of magnetic resonance cholangiopancreatography (MRCP). However respiratory motion artifact caused by a mismatch in respiratory rhythm has been experienced. The newly developed breath pacemaker was developed with the aim of providing the best match between the breath cycle and 2D-PACE trigger. The breath pacemaker is composed of two stimulators, an auto voice (AV) system and an auto light (AL) system. The two systems can be controlled separately or concurrently. Using the new breath pacemaker, improvement in MRCP image quality was evaluated in normal volunteers, and definite improvement was noted. Particularly good efficacy was obtained with concurrent control of the AV system and AL system. The results clearly demonstrated that the breath pacemaker can provide good synchronization of 2D-PACE and can lead to enhanced quality of MRCP images.