LI-RADS

LI-Rads2.0 Summary

 

 

LI-RADS Table 1 — Examples of Observations That May Be Categorized as Definitely Benign


Cyst
Hemangioma
Focal fat deposition
Focal fat sparing
Hypertrophic pseudomass interpreted as definitely benign
Wedge-shaped perfusional alterations
Confluent fibrosis
Focal scars
Some arterial-phase non-hyperenhancing atypical nodules
   Homogeneous siderotic nodules

* Note: Table 1 purposely does not include hepatic adenoma and focal nodular hyperplasias. The reason is that adenomas and large focal nodular hyperplasias are rare in cirrhotic livers.

** Note: Do not classify as LI-RADS 1 observations that have one or more ancillary features that favor the diagnosis of HCC. Table 5 lists ancillary features that favor the diagnosis of HCC.

*** Note: Perfusion alterations usually have no signal intensity abnormality on unenhanced images. If an observation is associated with signal intensity abnormalities on unenhanced images, a perfusion abnormality is unlikely.

LI-RADS Table 2 — Examples of observations that may be categorized as probably benign**


Atypical cyst (or probable cyst?)
Atypical hemangioma (or probable hemangioma?)
Atypical focal fat deposition (or probable focal fat hemangioma?)
Atypical focal fat sparing (or probable focal fat sparing?)
Hypertrophic pseudomass interpreted as probably benign
Rounded perfusional alterations*** (nodular arterial phase hyperenhancement, NAPH)
Patchy (changed from "florid") perfusional alterations***
Atypical confluent fibrosis (probable confluent fibrosis?)
Atypical focal scars (probable focal scars?)
Some arterial-phase non-hyperenhancing atypical nodules****
    Small (<2 cm) heterogeneous siderotic nodules
    Small (<2 cm) T1-hyperintense nodules
    Small (<2 cm) steatotic nodules
    Large (≥ 2cm) otherwise unremarkable nodules
Progressively enhancing observations

*Note: Table 2 purposely does not include hepatic adenoma and focal nodular hyperplasias. The reason is that adenomas and large focal nodular hyperplasias are rare in cirrhotic livers.

**Note: Do not classify as LI-RADS 2 observations that have one or more ancillary features that favor the diagnosis of HCC. Table 5 lists ancillary features that favor the diagnosis of HCC.

***Note: Perfusion alterations usually have no signal intensity abnormality on unenhanced images. If an observation is associated with signal intensity abnormalities on unenhanced images, a perfusion abnormality is unlikely.

****Note: Arterial-phase non-hyperenhancing atypical nodules may be categorized as LI-RADS 2 at the discretion of the radiologist. In general, atypical nodules categorized as LI-RADS 2 should not have major or ancillary features of HCC. Arterial-phase non-hyperenhancing atypical nodules with one or more major or ancillary features of HCC ususally should be categorized as LI-RADS 3 or 4.

LI-RADS Table 3 — Criteria for LI-RADS 3 Observations


A. <20mm

  • Masslike, arterial-phase hyperenhancement, with no Major Feature AND not definitely benign AND not probably benign
  • Masslike, arterial-phase hypoenhancement, with no or 1 Major Feature AND not definitely benign AND not probably benign
  • Non-masslike AND not definitely benign AND not probably benign
  • An observation that cannot be categorized as LI-RADS 1, 2, 4, 5 because of equivocal imaging features
  • An observation that meets criteria for LI-RADS 4 or 5 with stable imaging features for ≥ 2 years AND no increase in diameter for ≥ 2 years

B. 20mm or greater

  • Masslike, arterial-phase hypoenhancement, with no Major Feature AND not definitely benign or probably benign
  • Non-masslike AND not definitely benign AND not probably benign
  • An observation that cannot be categorized as LI-RADS 1, 2, 4, 5 because of equivocal imaging features
  • An observation that meets criteria for LI-RADS 4 or 5 with stable imaging features for ≥ 2 years AND no increase in diameter for ≥ 2 years

LI-RADS Table 4 — Ancillary Features that Favor Benignity


Uniform marked T2 hyperintensity
Uniform marked T2 hypointensity
Presence of normal, undistorted vessels coursing through observation
Follows blood pool on dynamic images
Progressive enhancement of observation (excluding septa and scars)
Clinical setting: in some clinical settings, hyper-enhancing benign nodules are common (e.g., hyperplastic nodules in Budd Chiari)
Decrease in diameter by ≥ 10 mm in absence of treatment

LI-RADS Table 5 — Ancillary Features that Favor Diagnosis of HCC


Ancillary Features Listed in Case Evaluation Form

Mild-moderate T2 hyperintensity
Capsule (discrete ring along marging of lesion that, compared to the ring alomng the margin of regenerative nodules in surrounding liver, is thicker or of greater conspicuity)
Mosaic architecture (includes nodule-in-nodule, multi-nodule-in-nodule, presence of discrete internal compartments or elements within observation )
High signal on DWI / Impeded diffusion / "Restricted" diffusion
Fat deposition disproportionate to that in surrounding liver
Iron sparing in iron-overloaded liver

As in current policy, only patients within Milan criteria (Stage T2) are eligible for an automatic HCC exception.
In the proposed policy, Stage T2 is defined as:
- 1 lesion ≥ 2 cm and ≤ 5cm, OR 2-3 lesions, all ≥ 1cm and ≤ 3cm in size.
- Lesions less than 1cm are indeterminate, and will not count towards the overall staging of HCC for automatic priority.

Stage T1 HCC would no longer be eligible for automatic priority, regardless of the AFP level.
A more precise classification scheme for liver nodules is also proposed (OPTN Class 0-5). Class 5 lesions meet all diagnostic criteria for HCC and are eligible to be considered for automatic HCC MELD exception.

Smaller lesions (1-2 cm) must meet more stringent imaging criteria than larger lesions (2-5cm) in order to be diagnosed as HCC on multiphase contrast enhanced imaging (CT or MRI) and qualify for automatic priority. Candidates will still be required to have more than one (may have two or three) smaller lesions to meet T2 criteria and qualify for MELD exception points.
- Lesions between 1-2 cm must be hypervascular on arterial phase imaging, and demonstrate portal vein/delayed phase washout and pseudocapsule enhancement. If both wash-out and pseudocapsule enhancement are not present, they must demonstrate growth on serial imaging.
- Lesions between 2-5 cm must be hypervascular on arterial phase imaging and demonstrate portal vein/delayed phase washout or pseudocapsule enhancement. If no wash-out or pseudocapsule enhancement, lesion must demonstrate growth on serial imaging.
- Lesions less than 1 cm are indeterminate (and thus, not eligible to be considered as HCC).

Liver imaging with multiphase contrast enhanced imaging (CT or MRI) must be performed or interpreted at a transplant center, and should meet minimum technical standards as described in Tables 4 and 5 of the policy.
For example, a candidate would be eligible for additional priority with:
Two 1.5 cm (5A) lesions; or
One 1.5 cm lesion (5A) and one 2.5 cm lesion (5B); or
One 3.5cm lesion (5B); or
Two 2.1cm lesions (5B).

The classification of HCC is summarized in the flow chart shown in Figure 1. While many of these terms may be unfamiliar to the non-radiologist, the criteria were developed by an expert panel of radiologists, and are considered to be minimum standards for appropriate radiologic diagnosis of HCC.

Glossary:
MELD Score
The Model (Originally Mayo) for End-Stage Liver Disease, or MELD, is a scoring system for assessing the severity of chronic liver disease. It was initially developed to predict death within three months of surgery in patients who had undergone a transjugular intrahepatic portosystemic shunt (TIPS) procedure,[1] and was subsequently found to be useful in determining prognosis and prioritizing for receipt of a liver transplant.[2][3] This score is now used by the United Network for Organ Sharing (UNOS) and Eurotransplant for prioritizing allocation of liver transplants instead of the older Child-Pugh score.[3][4]
Online Meld Calculator
In interpreting the MELD Score in hospitalized patients, the 3 month mortality is: [6]
40 or more — 71.3% mortality
30–39 — 52.6% mortality
20–29 — 19.6% mortality
10–19 — 6.0% mortality
<9 — 1.9% mortality

Milan Criteria
the original Milan criteria were applied as a basis for selecting patients with cirrhosis and hepatocellular carcinoma for liver transplantation.
The original Milan criteria stated that a patient is selected for transplantation when he or she has:
one lesion smaller than 5cm.
up to 3 lesions smaller than 3 cm.
no extrahepatic manifestations
no vascular invasion

In 2011, more stringent criteria were suggested in light of the fact that misclassifications were being made in the case of smaller lesions

OPTN The Organ Procurement and Transplantation Network
http://optn.transplant.hrsa.gov/

UNOS

LINKS:

http://optn.transplant.hrsa.gov/