Concept:
Observation is probably HCC but there is not 100% certainty.
Definition:
Observation with imaging features suggestive but not diagnostic of HCC.
Criteria:
Not definite benign entity, not probable benign entity, not non-HCC malignancy, not tumor in vein and as follows:
< 20mm observation
≥ 20mm observation
If unsure about category
- Categorize as LR-4 if unsure between LR-4 and LR-5
- Categorize as LR-3 if unsure between LR-4 and LR-3
Reporting:
- LR-4 observations must be reported.
- Features seen on CT and MR can be integrated to yield the final LI-RADS category. If this is done, it must be explicitly stated in the radiology report.
- Since LR-4 observations represent probable HCC, it is important to follow these observations closely. Thus LR-4 observations must be reported.
- LR-4 observations may be reported in aggregate if there are numerous observations which share similar features. However, up to five such observations should be individually described in the Findings, if there are no LR-M, LR-5V, or LR-5 observations.
Please see Diagnostic Options for details
Comments:
- Does not contribute to radiology T staging unless multiple LR-4 observations are present that individually do not meet LR-5 criteria but in aggregate are diagnostic of multifocal (stage T4a) HCC.
- Does not provide HCC exception points for determining priority on liver transplantation list.