During NHANES II, conducted from 1976-1980, X-rays of the cervical spine were collected at the mobile examination center (MEC) for survey participants aged 25-74 years and older, and of the lumbar spine for men aged 25-74 years and women aged 50-74. Exclusions included known pregnancy. More details can be found in the Instruction Manual Data Collection, Part 15a (cdc.gov), Chapter 13 X-RAY.
A lateral view of the cervical spine in maximum flexion was captured for each eligible participant. Participants were instructed to hold a weight in each hand to keep their shoulders down. A lateral view of the lumbar spine on expiration was captured for each eligible participant. The x-ray films were developed and read by the physician on the MEC for assessment and quality. However, no data files based on radiologic readings of the cervical and lumbar spine x-rays were ever released.
This release provides digitized images for NHANES II cervical and lumbar spine x-rays. These digitized x-ray images had been publicly released previously on the NIH National Library of Medicine (NLM) website under a prior interagency agreement (IAA) between NCHS and NLM. The scanning and public release of these images occurred in the early 1990s. In April 2025, the digitized images of these cervical and lumbar spine x-rays were transferred back to NCHS. The current file release contains the digitized spine images previously available on the NLM website, except for a small number of images that were unviewable or had target age errors (i.e., lumbar spine images for women between 25-49 years).
The current release includes 17,075 files; each contains one digitized image of the cervical or lumbar spine x-ray film.
| Cervical Spine X-ray Images | Lumbar Spine X-ray Images | Total X-ray Images | |
|---|---|---|---|
| Total | 9,667 | 7,408 | 17,075 |
These 17,075 x-ray images are from 9,700 participants:
Among the 9,698 participants with any spine x-ray images, there are:
Participants aged 25-74 years and older who participated in the MEC exam and were not pregnant at the time of exam were eligible for the cervical spine x-ray image. MEC examined men aged 25-74 years and older and women 50-74 years and older who were not pregnant at the time of exam were eligible for the lumbar spine x-ray image.
The digitized images received from the NLM are included in this release after removing unviewable images or those with target age errors.
Images were converted to Tagged Image File Format (TIFF) using a standard lossless compression algorithm to compress the original files without losing quality. The original files obtained from NLM were 12-bit that were originally saved using big-endian byte order. These original files were scaled up to 16-bit for this file release. The TIFF files do not require special software to view.
File names include the type of spine image, “C” for cervical spine or “L” for lumbar spine, followed by participant ID. For example, “C00179.tiff” indicates a cervical spine image for participant with SEQN=179. The SEQN can have up to 5 digits and can be used to access data from the main NHANES II public use datasets for the corresponding participants.
Digitized x-ray images do not contain directly analyzable data and should be interpreted using radiological expertise with the conditions being assessed. The results of radiologic readings can be merged with the NHANES II data and subsequent analyses should use the NHANES examination sample weights. Please refer to NHANES II (1976-1980) for additional documentation.
The current release consists of 17,075 TIFF files. Due to the quantity of the data, these files are stored at the CDC File Transfer Protocol (FTP) Server. To access, please click on the Cervical and Lumbar Spine X-ray Images (August 2025) link on the NHANES II (1976-1980) webpage. This link will take users to the FTP folder containing all 17,075 TIFF files. Users can either click the individual hyperlinks to download selected files manually or write a script in the language of their choice to download all the files together.