Mieke Bus

6 89 Figure 1: Study set up: OCT measurement and ELUS measurements were performed during CT imaging. CT imaging allowed co-registration. This figure demonstrates our study set up while performing OCT measurements which was followed directly by ELUS measurements. $: nephroureterectomy specimen. ! Insertion of OCT probe in the ostium of the resected bladder cuff. @ OCT probe. * During each measurement saline was manually injected in by the probe into the ureter to ensure dilated lumen for optimal measurements. # OCT device. In total five complete resected nephroureterectomy specimens including bladder cuff of patients with biopsy confirmed UUT-UC were examined using serial OCT and ELUS measurements combined with co-registered CT. Immediately after surgery, the specimens were transported to the radiology department to perform OCT, ELUS and CT imaging. Following CT, OCT and ELUS imaging, the specimens were transported to the pathology department for histopathological processing. This study was approved by the Institutional Review Board in 2013, Academic Medical Center, Amster- dam. The Institutional Review Board waived the need for written informed consent of the participants. Optical Coherence Tomography (OCT) Imaging OCT images were obtained as described previously by our group. (4) The OCT system used was the Illumien Intravascular Imaging System, interfaced to a C7 Dragonfly tm 2.7Fr (0.9mm) Imaging Probe (St. Jude Medical, St. Paul Minnesota, USA) with an axial resolution of 15µm and an lateral resolution of 20-40µm. (9) First, an OCT imaging probe was introduced through the ureteral orifice up to the renal pelvis. Subsequently, OCT images were acquired by retracting the imaging probe using an automatic pullback system at a pullback speed of 10mm/s, while rotating acquiring 100 frames/s, across a trajectory of 54mm. This resulted in a 540-frame dataset in 5.4 seconds. After pullback, the imaging probe was manually