A Novel Dual-Element Catheter for Improving Non-Uniform Rotational Distortion in Intravascular Ultrasound

For the early diagnosis of atherosclerosis and interventions, intravascular ultrasound (IVUS) is a valuable tool for intravascular luminal imaging. Compared with the array-based method, mechanically rotating IVUS catheters dominate the clinical applications because of their less complexity and better suitability for high-frequency ultrasound imaging. However, mechanically rotating catheters are suffering from non-uniform rotational distortion (NURD) which hinders accurate image acquisition. In this study, a dual-element imaging catheter is proposed, in which two elements with the same frequency and similar performance are assembled in a back-to-back arrangement. When the catheter encounters a NURD due to acute bending, the abnormal image of one element can be replaced by the normal image of the opposite element, thus eliminating the NURD in the reconstructed image. Moreover, two images can be obtained in one rotation and the imaging frame rate is doubled in the absence of NURD. The performance of the two elements was quantitatively assessed by a wire phantom. And the complementary imaging protocols were evaluated by a tissue phantom and ex vivo porcine vessel. The results show that the proposed strategy can be promising in clinical studies.