| Title: |
Discrimination tasks in simulated low‐dose CT noise |
| Authors: |
Abbey, Craig K; Samuelson, Frank W; Zeng, Rongping; Boone, John M; Myers, Kyle J; Eckstein, Miguel P |
| Source: |
Medical Physics, vol 50, iss 7 |
| Publisher Information: |
eScholarship, University of California |
| Publication Year: |
2023 |
| Collection: |
University of California: eScholarship |
| Subject Terms: |
5105 Medical and Biological Physics (for-2020); 40 Engineering (for-2020); 51 Physical Sciences (for-2020); 4003 Biomedical Engineering (for-2020); Clinical Research (rcdc); Biomedical Imaging (rcdc); Humans (mesh); Image Processing; Computer-Assisted (mesh); Tomography; X-Ray Computed (mesh); Phantoms; Imaging (mesh); Algorithms (mesh); discrimination tasks; observer performance; ramp-spectrum noise; 0299 Other Physical Sciences (for); 0903 Biomedical Engineering (for); 1112 Oncology and Carcinogenesis (for); Nuclear Medicine & Medical Imaging (science-metrix) |
| Time: |
4151 - 4172 |
| Description: |
BACKGROUND: This study reports the results of a set of discrimination experiments using simulated images that represent the appearance of subtle lesions in low-dose computed tomography (CT) of the lungs. Noise in these images has a characteristic ramp-spectrum before apodization by noise control filters. We consider three specific diagnostic features that determine whether a lesion is considered malignant or benign, two system-resolution levels, and four apodization levels for a total of 24 experimental conditions. PURPOSE: The goal of the investigation is to better understand how well human observers perform subtle discrimination tasks like these, and the mechanisms of that performance. We use a forced-choice psychophysical paradigm to estimate observer efficiency and classification images. These measures quantify how effectively subjects can read the images, and how they use images to perform discrimination tasks across the different imaging conditions. MATERIALS AND METHODS: The simulated CT images used as stimuli in the psychophysical experiments are generated from high-resolution objects passed through a modulation transfer function (MTF) before down-sampling to the image-pixel grid. Acquisition noise is then added with a ramp noise-power spectrum (NPS), with subsequent smoothing through apodization filters. The features considered are lesion size, indistinct lesion boundary, and a nonuniform lesion interior. System resolution is implemented by an MTF with resolution (10% max.) of 0.47 or 0.58 cyc/mm. Apodization is implemented by a Shepp-Logan filter (Sinc profile) with various cutoffs. Six medically naïve subjects participated in the psychophysical studies, entailing training and testing components for each condition. Training consisted of staircase procedures to find the 80% correct threshold for each subject, and testing involved 2000 psychophysical trials at the threshold value for each subject. Human-observer performance is compared to the Ideal Observer to generate estimates of task efficiency. The ... |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
unknown |
| Relation: |
qt38q7t77q; https://escholarship.org/uc/item/38q7t77q; https://escholarship.org/content/qt38q7t77q/qt38q7t77q.pdf |
| DOI: |
10.1002/mp.16412 |
| Availability: |
https://escholarship.org/uc/item/38q7t77q; https://escholarship.org/content/qt38q7t77q/qt38q7t77q.pdf; https://doi.org/10.1002/mp.16412 |
| Rights: |
CC-BY |
| Accession Number: |
edsbas.133B46FA |
| Database: |
BASE |