NLST Images -- General Details
Dates
The Study Dates are fictitious. While appearing real, they are coded to represent the 3 screening years:
- 19990102 -- Screening Year 0
- 20000102 -- Screening Year 1
- 20010102 -- Screening Year 2
Patient Identifiers
The Patient Identifiers (PIDs), in DICOM tag (0010, 0020) Patient ID, are 6 digit random numbers assigned by IMS. They are called IMS-Global-IDs. PIDs beginning with '1' are LSS images; those beginning with '2' are ACRIN images; examples:
- 101337 is an LSS PID
- 208344 is an ACRIN PID
Prior ACRIN and LSS PIDs may be found in 2 DICOM tags: (0010, 1000) Other Patient IDs and (0013, 0040) Clinical Trial Subject ID. These prior-PIDs are random 4- or 5-digit (ACRIN) or 6-digit (LSS) numbers that contain no screening site information; the LSS prior-PIDs may have leading zeroes which may or may not appear unless specified that they do so; examples:
- 2542 is an ACRIN prior-PID
- 18519 is an ACRIN prior-PID
- 022921 is an LSS prior-PID that may also be rendered as 22921
Patient Names
Patient Names appearing in DICOM tag (0010, 0010) are a construct from the participant's prior PID concatenated with a caret and the string 'ACRIN' or 'LSS'; examples:
- 2542^ACRIN
- 18519^ACRIN
- 022921^LSS
Series Descriptions
The original Series Descriptions, if present, were often vague and/or, at best, inconsistent.
New Series Descriptions consist of 11 coded comma-separated values, listed below. Code value descriptions may be found in the attachment Series-Description-Details.xlsx.
- (1) Screening Year
- (2) Image Type
- (3) Manufacturer
- (4) Scanner Model
- (5) Convolution Kernel
- (6) Reconstruction Diameter
- (7) Slice Thickness
- (8) kVp
- (9) mAs
- (10) Effective mAs
- (11) Slice Thickness