This article [J. Biomed. Opt. 23(9), 091415(2018)] was originally published online 4 September 2018, with an error involving the images presented for Figs. 6 and 7. The image presented for Fig. 6 should have been presented for Fig. 7, and vice versa. All captions and textual references involving these figures were otherwise correct.

The images for Figs. 6 and 7 in this article were corrected online on 7 September 2018.

They appear correctly in print.