Fig 1.
Multimodal imaging assessment during the development of our local injury method of tumor cell implantation.
(A) BLI acquisition of MB49-luc tumor-bearing C57Bl/6 mice during local injury method 18 minutes after s.c. luciferin injection. BLI is expressed as the number of photons/sec; the graph is representing the increase in bioluminescence activity over time (n = 7, mean ± SD). Difference in bioluminescence emission is minimal between both groups. (B) HRUS results expressed as tumor volume in mm3 over time after tumor cell implantation (n = 7, mean ± SD). High (n = 2) and low (n = 5) tumor growth kinetics could be observed, thereby distinguishing two growth patterns of tumor formation. (C) Serial PAI measurements showing average sO2 values in tumor bearing mice. Similar trends in sO2 values can be observed in animals with high (n = 2) and low (n = 5) tumor growth kinetics, though a more pronounced drop in sO2 levels was observed in animals with high tumor growth kinetics.
Fig 2.
BLI, HRUS and PAI images taken at day 17 post-injection.
(A) BLI displays intense luminescence emission (left image), HRUS shows a tumor volume of 102.6 mm3(middle image), PAI demonstrates an oxygenated tumor center (right image). Oxygen saturation levels ranging from 0% (blue) to 100% (red). An absence of signal is displayed by black pixels. (B) Discordant results between BLI/PAI and HRUS, demonstrating aberrant growth pattern.
Fig 3.
Longitudinal multimodal assessment of bladder tumor growth.
All multimodal images were taken at the same days for optimal comparison. (A) bladder tumor growth visualized by serial BLI images of a representative mouse taken 18 minutes after s.c. luciferin injection. An increase in tumor volume can be observed in serial 3D HRUS (B) images and longitudinal 2D sections (C). During the time course of tumor growth a decrease in oxygen saturation (D) from early-stage tumor to later stage tumors was observed.
Fig 4.
Longitudinal multimodal imaging assessment of in vivo bladder tumor growth.
(A) BLI acquisition of MB49-luc tumor-bearing C57Bl/6 mice during local injury method 18 minutes after s.c. luciferin injection. BLI is expressed as the number of photons/sec; the graph is representing the increase in bioluminescence activity over time (n = 4, mean ± SD). (B) HRUS results expressed as tumor volume in mm3 over time after tumor cell implantation (n = 4, mean ± SD). (C) Serial PAI measurements showing average sO2 values in tumor bearing mice (n = 4, mean ± SD).
Fig 5.
HRUS is able to provide specific anatomical information of bladder tumor development in a 3-dimensional plane. The tumor size was assessed based on the ROIs drawn around the tumor borders for every slice of 125 μm. Tumor is marked in blue.
Fig 6.
Visualization of the scratching procedure with HRUS.
HRUS images were obtained during the optimized local injury method in a sham mouse. Marked in blue and red is the scratching blunted needle and the bladder wall, respectively. (A) scratching of the bladder wall for 1 minute, (B) bladder immediately after the procedure, (C) bladder region after 10 days.
Fig 7.
Comparison of BLI, HRUS and PAI images with macroscopic analysis of tumor volumes.
(A) BLI image, (B) longitudinal section of the bladder of HRUS image, (C) PAI image and (D) ex vivo bladder on sacrificing day for comparison of multimodal images and macroscopic analysis of tumor volumes.
Fig 8.
Histopathology and immunohistochemistry.
(A) HE images confirm imaging results and show tumor growth extending from the bladder wall in to the bladder lumen. Tumor bearing mice show (B) positive Ki-67 staining, (C) positive PECAM staining as well as (D) high TRAIL expression.