Visual adaptation and the amplitude spectra of radiological images

Abstract

We examined how visual sensitivity and perception are affected by adaptation to the characteristic amplitude spectra of X-ray mammography images. Because of the transmissive nature of X-ray photons, these images have relatively more low-frequency variability than natural images, a difference that is captured by a steeper slope of the amplitude spectrum (~ − 1.5) compared to the ~ 1/f (slope of − 1) spectra common to natural scenes. Radiologists inspecting these images are therefore exposed to a different balance of spectral components, and we measured how this exposure might alter spatial vision. Observers (who were not radiologists) were adapted to images of normal mammograms or the same images sharpened by filtering the amplitude spectra to shallower slopes. Prior adaptation to the original mammograms significantly biased judgments of image focus relative to the sharpened images, demonstrating that the images are sufficient to induce substantial after-effects. The adaptation also induced strong losses in threshold contrast sensitivity that were selective for lower spatial frequencies, though these losses were very similar to the threshold changes induced by the sharpened images. Visual search for targets (Gaussian blobs) added to the images was also not differentially affected by adaptation to the original or sharper images. These results complement our previous studies examining how observers adapt to the textural properties or phase spectra of mammograms. Like the phase spectrum, adaptation to the amplitude spectrum of mammograms alters spatial sensitivity and visual judgments about the images. However, unlike the phase spectrum, adaptation to the amplitude spectra did not confer a selective performance advantage relative to more natural spectra.Electronic supplementary materialThe online version of this article (10.1186/s41235-018-0089-4) contains supplementary material, which is available to authorized users.

Visual adaptation to medical images: a comparison of digital mammography and tomosynthesis

“…In this study, we explored the impact of well-established processes of sensory adaptation for influencing visual perception of x-ray projection mammography and tomosynthesis images. Our work specifically builds on the previous studies by Kompaniez et al [16][17][18] to ask how these adaptation effects depend on the imaging modality. Our results suggest that DM and DBT modalities show comparable levels of adaptation to the textural properties of breast images as characterized by measures such as the BI-RADS density classifications and point to differences specific to the two modalities at least in terms of the measured sensitivity for detecting image noise.…”

“…Adaptation also influenced the perceived blur in the images. 17 And importantly, adapting to a particular image texture (again dense or fatty) resulted in subtle but significant improvements in search times for finding simulated lesions added to the images. 18 These results suggest that the visual properties of digital mammogram images can serve as potent stimuli for adaptation and that this adaptation could in principle influence both the perception and performance of radiologists.…”

Multicenter Study of Whole Breast Stiffness Imaging by Ultrasound Tomography (SoftVue) for Characterization of Breast Tissues and Masses

“…Spatial filtering is a relatively common post-processing step that can emphasize or deemphasize structures based on their size [ 25 ]. A high pass spatial filter (i.e., suppressing spatial scales >1.5 cm) was applied to all images in order to emphasize masses while deemphasizing adjacent fibroglandular tissue that could mask some of the mass properties.…”

Fatigue in radiology: a fertile area for future research

“…В работе E. Kompaniez-Dunigan и соавт. [26] по изучению зрительной адаптации при описании рентгеновских снимков говорится о необходимости дальнейшего изучения вопроса о её влиянии на точность интерпретируемых результатов в процессе выполнения задачи.…”