By collecting chest low-dose spiral CT plain scan images, extracting effective features from the adrenal gland regions, training and validating an artificial intelligence-based automatic diagnostic algorithm for adrenal nodules, we will ultimately develop an artificial intelligence software with independent intellectual property rights that is specifically designed for screening adrenal nodules in chest low-dose CT scans.

Inclusion Criteria:

1. The age of the population is over 18 years old, regardless of gender;
2. Images from chest low-dose CT plain scan during routine physical examination;

Exclusion Criteria:

1. Patients with a history of malignant tumors;
2. Imaging images with poor quality, artifacts, etc., which make analysis impossible.

The study population consists of individuals aged over 18 years, with no gender restrictions, who underwent chest low-dose CT scans as part of routine physical examinations. Notably, those with a history of malignant tumors are excluded, and only individuals with qualified imaging data (free from poor quality, artifacts, or other issues that hinder analysis) are included.