Miniature forward-viewing common-path OCT probe for imaging the renal pelvis.

Xiaoyong Fu,Gregory Maclennan,Hui Zhu,Michael W Jenkins,Yves T Wang,Andrew M Rollins,Dhruti Patel

doi:10.1364/boe.6.001164

Abstract

We demonstrate an ultrathin flexible cone-scanning forward-viewing OCT probe which can fit through the working channel of a flexible ureteroscope for renal pelvis imaging. The probe is fabricated by splicing a 200 µm section of core-less fiber and a 150 µm section of gradient-index (GRIN) fiber to the end of a single mode (SM) fiber. The probe is designed for common-path OCT imaging where the back-reflection of the GRIN fiber/air interface is used as the reference signal. Optimum sensitivity was achieved with a 2 degree polished probe tip. A correlation algorithm was used to correct image distortion caused by non-uniform rotation of the probe. The probe is demonstrated by imaging human skin in vivo and porcine renal pelvis ex vivo and is suitable for imaging the renal pelvis in vivo for cancer staging.

Highlights

Cancers arising from the surface lining of hollow organs account for the most of cancer deaths in the world
We demonstrate an ultrathin flexible cone-scanning forwardviewing optical coherence tomography (OCT) probe which can fit through the working channel of a flexible ureteroscope for renal pelvis imaging
The probe is designed for common-path OCT imaging where the back-reflection of the GRIN fiber/air interface is used as the reference signal

Summary

Introduction

Cancers arising from the surface lining of hollow organs account for the most of cancer deaths in the world. Upper-tract urothelial carcinoma (UTUC), urothelial cancer of the ureter and renal pelvis, accounts for 5-10% of urothelial carcinomas. Radical nephroureterectomy (RNU) is currently the gold standard of treatment for most UTUCs [1] This may represent a significant over-treatment for about 40% of all UTUCs which are non-invasive and have very low progression risk [2]. Recent studies show that endoscopic treatment is an alternative method for low-grade and low-stage UTUCs, and this conservative treatment preserves renal function and is preferred because of the risk of cancer occurrence in the contralateral renal unit [1]. When the UTUC is localized in the renal pelvis, a side-viewing probe designed to image the side wall of tubular organs like ureter is not appropriate. The irregular shape of the renal pelvis would be better accessed by a forward-viewing probe

Methods

Results

Conclusion