I’ve encountered a discrepancy when comparing the LOINC main distribution table and the LOINC RSNA Playbook, and I’m hoping someone can help clarify the differences.
There seems to be around 109 codes from the RAD and PANEL.RAD class from the LOINC table which are not available in the Playbook.
Some examples below (from v2.82):
LOINC_NUM
CLASS
STATUS
LONG_COMMON_NAME
100225-2
RAD
ACTIVE
Bone density quantitative ultrasound study
101804-3
RAD
ACTIVE
Bone DXA Calcaneus [T-score] Bone density
101805-0
RAD
ACTIVE
Bone DXA Calcaneus [Z-score] Bone density
Questions:
Were these intentionally excluded because of curation?
Thank you for inquiry and your careful comparison between the LOINC main distribution table and the LOINC‑RSNA Radiology Playbook. You are correct that there are LOINC codes from the RAD and PANEL.RAD class that appear in the main LOINC distribution but are not present in the Playbook. This is expected, due to how the Playbook is defined and curated.
The Playbook is a curated subset of LOINC, developed jointly with RSNA, and does not aim to include all LOINC terms in the RAD or PANEL.RAD classes. The codes you mentioned (e.g., calcaneal DXA T-score/Z-score and quantitative ultrasound studies) are valid and active in LOINC, but they are generally not modeled as orderable radiology procedures in the Playbook. In general, the Playbook excludes: 1) result-level observations (e.g., T-scores, Z-scores, measurements); 2) highly granular or device-specific variations that are not broadly used for ordering; and 3) concepts that fall outside radiology workflow standardization priorities.
That said, we continuously evaluate gaps. If there are specific codes that you believe represent orderable procedures and should be included, we welcome those for review.
