Introduction
Access to NLST images and data require approval of the National Cancer Institute (NCI). For details, please see: https://biometry.nci.nih.gov/cdas/studies/nlst.
Those who do have access may obtain non-image data via a Query Tool that is a user-friendly menu-picker that builds database queries without the need to know the database query language. The Query Tool also allows one to download images related to query findings.
For those investigators wanting images without using the Query Tool, if approved by NCI, they may provide a hard drive to TCIA staff who can fill the hard drive with requested images.
Usage of the Query Tool and images provided by hard drives is described below.
Query-Tool Accesses
Currently, the Query Tool database does not record accesses unless a request is query includes Series Instance UIDs which can be used to download images. Nor does the Query Tool database record requests to download images since, once the request is made, the Query Tool turns control over the NBIA Download Manager; the Query Tool never knows whether or not the person requesting images to be downloaded actually ever downloaded them, Furthermore, the image-request passed to the Download Manager does not include any information about the requestor. Nonetheless, here is a summary of queries with associated images; the report is from late 2012 to July 2014.
Download Statistics
The download activity since January 2013 is graphed below. Except for 5.6 Terabyte spike in June 2013, downloads average less than 0.5 TBytes/month.
NLST-Series-Downloads-by-Month.xlsx
Hard-Drive Requests
Filling hard-drive requests eliminate the need for a investigator to wait for lengthy download. These requests are more sporadic than monthly downloads. For example, in June, 2014, we provided 1.5 TBytes of images (images from 3,200 subjects) on hard drives but none other in 2014.