LI-RADS Minimum Reporting Standards
- LI-RADS is most useful when imaging reports provide standardized information to guide clinical management. The guidelines below provide a minimum level of reporting detail for liver observations in patients at risk for developing hepatocellular carcinoma. These reporting guidelines are in addition to the routine clinical scan report.
- Note that any portion of these guidelines and template may be adapted or combined with existing reporting templates according to radiologist or institutional preferences.
Technique:
- State whether the scan meets minimum LI-RADS technical recommendations:
- CT:
- At a minimum, hepatic arterial, portal venous, and delayed phase imaging is included.
- Pre-contrast imaging may also be obtained.
- Late hepatic arterial phase is strongly preferred, which is timed such that the portal vein is at least partially opacified but the hepatic veins are not opacified in an antegrade fashion
- The entire liver is included in all phases
- Multi-planar reformations are recommended.
- MRI:
- Imaging includes at a minimum:
- Precontrast in- and opposed-phase imaging
- T2-weighted imaging (single shot or fast spin echo)
- T1-weighted precontrast, hepatic arterial, portal venous, and delayed phases (fat suppression preferred)
- Late hepatic arterial phase is strongly preferred, which is timed such that the portal vein is at least partially opacified but the hepatic veins are not opacified in an antegrade fashion
- Multi-planar images recommended (direct multi-planar acquisitions are preferred over reformations)
- The entire liver is included in all series.
- Diffusion-weighted imaging is suggested
- State whether there is substantial image degradation due to patient habitus, motion, other artifacts, late hepatic arterial phase mistiming, etc.
Findings:
- When describing LR-5 observations, explicitly describe the subcategory to which they belong (LR-5, LR-5us, or LR-5g).
- If there are more than five LR-4, LR-5, LR-5V, or LR-M observations, the observations may be reported in aggregate.
- If not innumerable, up to five of the highest categorized LR-4, LR-5, LR-5V, and LR-M observations should be reported individually. Additional LR-4, LR-5, LR-5V, and LR-M observations may be reported in aggregate. For observations reported individually:
- Use the terms from the LI-RADS lexicon.
- For each observation, state at a minimum:
- Diameter (maximal long-axis dimension) and the series and image number on which it was measured
- Location of observations in the liver by Couinaud segment(s)
- Major features contributing to LI-RADS categorization
- Features seen on prior CT or MR can be integrated to yield the final LI-RADS category. If this is done, it must be explicitly stated in the report.
- LR-3 observations which were reported on previous examinations as LR-4, LR-5, or LR-M should be reported.
- LR-3 observations which were NOT reported previously as LR-4, LR-5 or LR-M:
- Should be reported if no LR-4, LR-5, LR-5V or LR-M observations are reported, and may be reported in aggregate
- If LR-4, LR-5, or LR-M observations are reported, LR-3 may be reported at the radiologist’s discretion, and may be reported in aggregate.
- New observations and previously identified observations that rise in category (eg from LR-3 on prior examination to LR-4 on current examination) should be reported. These should be reported individually if they are ranked higher than other reported observations until up to five observations are reported individually; additional new observations or observations that rise in category may be reported in aggregate.
- As observations evolve (arise new, change or are treated), labeling should remain consistent from report to report, according to the first designation of each observation. For example, if an observation is labeled “Observation 2” at first description, it should be described as “Observation 2” on all future reports.
- LR-1 and LR-2 observations may be reported at the radiologist’s discretion, and may be reported in aggregate, with the following exception. LR-1 and LR-2 observations that were previously reported as LR-3, LR-4, LR-5, or LR-M should be reported individually.
- When findings from associated ultrasound examinations or other modalities are used as ancillary features for diagnosis, this use of other modalities and features must be explicitly mentioned. In addition, the specific examinations used and their acquisition dates must be detailed in the “Comparison” section of the report.
Impression:
- If the scan does not meet minimum LI-RADS technical recommendations, state this.
- Report LR-M (possible non-HCC malignancy) observations.
- Succinctly describe the number of LR-3, LR-4, LR-5 and LR-5V observations, up to five total, after which the term “more than five” may be used:
- Describe the highest LI-RADS category observations first (LR-5V, LR-5, then LR-4, then -3, if appropriate), including, if measurable, their diameter.
- LI-RADS observations of the same category may be summarized in aggregate in the impression.
- If comparison has been made with a prior examination, interval diameter increase/reduction or change in imaging characteristics of reported observations should be described in the impression. When appropriate, these may be reported in aggregate (eg. “three LR-4 observations, unchanged in diameter”).
- LR-1 and LR-2 observations may be omitted from the impression at the discretion of the radiologist, or may be reported in aggregate.
- Optional:
- The radiologic T-stage may be stated. Generally, only LR-5 and LR-5V observations contribute to the Radiological T-stage. Observations categorized as LR-1, LR-2, LR-3, and LR-4 do not contribute to the radiologic T-stage, unless multiple LR-4 observations in aggregate are interpreted as multifocal HCC.
- Diagnostic options may be stated. Recommendations are discussed here.
Links to reporting templates:
Sample template:
Procedure: [MRI Abdomen with and without contrast – (date)]
Indication: [Underlying liver disease, surveillance for hepatocellular carcinoma, history of treatment]
Comparison: [Include modality, presence/absence of contrast material on prior, and date]
Technique: [Precontrast and dynamic postcontrast MR imaging of the abdomen was performed.] [MRCP was also performed.] [Additional sequences may be described at institutional discretion.] Examination [meets LI-RADS technical recommendations.] [is compromised by the following factor(s): ().]
Intravenous contrast agent: [type]
Volume: [] mL
Rate: [] mL/sec
[Premedication/adverse events:]
Findings:
Liver: [morphology and signal intensity, diffuse findings]
Focal hepatic observations: [for each observation, provide diameter and series/image on which it was measured, hepatic segment, major features, LI-RADS category, and change since prior; describe vascular involvement if applicable].
[Observation 1 – LI-RADS (category), (features as above).]
[Observation 2 – LI-RADS (category), (features as above).]
[Observation 3 – LI-RADS (category), (features as above).]
Hepatic vasculature: [anatomic variants, patency]
Biliary system: []
Extrahepatic findings: [none, splenomegaly, collaterals, ascites].
[Other organs, findings, etc.:]
Impression:
Hepatic findings:
[Summary of LI-RADS observations; or LI-RADS negative.]
[Additional liver findings as above.]
Extrahepatic findings:
[None]
_______________
LI-RADS M = Possible non-HCC malignancy
LI-RADS 5V = Definitely hepatocellular carcinoma with tumor in vein
LI-RADS 5 = Definitely hepatocellular carcinoma (concordant with OPTN 5)
LI-RADS 4 = Probably hepatocellular carcinoma
LI-RADS 3 = Intermediate probability for hepatocellular carcinoma
LI-RADS 2 = Probably benign
LI-RADS 1 = Definitely benign
NOTE: LI-RADS categories should be interpreted in the context of other available data, such as biomarkers and the patient’s prior probability of developing or having hepatocellular carcinoma. The LI-RADS / OPTN classification of liver lesions has been adopted to standardize CT and MRI scan reporting in patients at risk for hepatocellular carcinoma. The imaging criteria for “definite hepatocellular carcinoma” are concordant for the LI-RADS and OPTN systems. LI-RADS criteria and documentation are available online at www.acr.org/LI-RADS. This report utilizes LI-RADS version 2014.1.