Abstract
BACKGROUND AND PURPOSE: MR imaging is useful for the detection and/or confirmation of optic neuritis. The objective of this study was to determine whether a postprocessing algorithm selectively increases the contrast-to-noise ratio of abnormal optic nerves in optic neuritis, facilitating this diagnosis on MR imaging.
MATERIALS AND METHODS: In this retrospective case-control study, coronal FLAIR images and coronal contrast-enhanced T1WI from 44 patients (31 eyes with clinically confirmed optic neuritis and 28 control eyes) underwent processing using a proprietary postprocessing algorithm designed to detect and visually highlight regions of contiguous increases in signal intensity by increasing the signal intensities of regions that exceed a predetermined threshold. For quantitative evaluation of the effect on image processing, the contrast-to-noise ratio of equivalent ROIs and the contrast-to-noise ratio between optic nerves and normal-appearing white matter were measured on baseline and processed images. The effect of image-processing on diagnostic performance was evaluated by masked reviews of baseline and processed images by 6 readers with varying experience levels.
RESULTS: In abnormal nerves, processing resulted in an increase in the median contrast-to-noise ratio from 17.8 to 85.0 (P < .001) on FLAIR and from 19.4 to 93.7 (P < .001) on contrast-enhanced images. The contrast-to-noise ratio for control optic nerves was not affected by processing (P = 0.13). Image processing had a beneficial effect on radiologists' diagnostic performance, with an improvement in sensitivities for 5/6 readers and relatively unchanged specificities. Interobserver agreement improved following processing.
CONCLUSIONS: Processing resulted in a selective increase in the contrast-to-noise ratio for diseased nerves and corresponding improvement in the detection of optic neuritis on MR imaging by radiologists.
ABBREVIATIONS:
- CIE
- correlative image enhancement
- CNR
- contrast-to-noise ratio
Footnotes
Disclosures: Aseem Sharma—RELATED: Other: Correlative Enhancement LLC, Comments: The algorithms used in this study were coinvented by me. I hold the intellectual property rights to these patented algorithms. I have founded a company (Correlative Enhancement LLC) with the aim of future commercialization of this intellectual property. I am the sole proprietor of the company, and since the inception of the company until now (including the time during which I processed the images for this study), this company has not received funding from any external source. While I used the algorithms to process the images for this study, I did not participate in image review, image analysis, or the subsequent statistical analysis; UNRELATED: Consultancy: Biomedical Systems, Comments: As a consultant, I serve as an independent reviewer for imaging studies performed for research by third parties; Patents (Planned, Pending or Issued): “Method for Medical Image Analysis and Manipulation,” US patent No. 9,846,937, December 19, 2017; Stock/Stock Options: GE Healthcare, Comments: I own publicly traded GE Healthcare stocks (current value of $10–15,000) in a company that makes imaging equipment among other things. Amber Salter—UNRELATED: Consultancy: Circulation Cardiovascular Imaging journal.
Data previously presented at: North American Neuro-Ophthalmology Society Annual Meeting, March 3–8, 2018; Waikoloa Village, Hawaii; and the American Academy of Neurology Annual Meeting, April 21–27, 2018; Los Angeles, California.
- © 2019 by American Journal of Neuroradiology
