Ijin Joo1, Jeong Min Lee1, Dong Ho Lee1, Su Joa Ahn1, Eun Sun Lee2, and Joon Koo Han1
1Radiology, Seoul National University Hospital, Seoul, Korea, Republic of, 2Radiology, Chung-Ang University Hospital, Seoul, Korea, Republic of
Synopsis
The latest Liver Imaging Reporting And Data System (LI-RADS v2014) incorporates gadoxetic acid-enhanced MRI into the diagnostic algorithm of hepatocellular carcinoma (HCC). In this study, we investigated the effects of ancillary features of gadoxetic acid-enhanced MRI in the determination of LI-RADS categories of HCCs. On gadoxetic acid-enhanced MRI, LI-RADS showed sensitivities of 69.0% and 67.8% in the diagnosis of HCCs (LR-5/5v) in two reviewers, respectively. Ancillary features of HCCs on gadoxetic acid-enhanced MRI including hepatobiliary imaging features frequently resulted in upgrade LR-3 to LR-4.
Introduction
The Liver Imaging Reporting And Data System (LI-RADS), first launched in 2011 and
recently updated in 2014, is a system for the standardized interpretation of CT
and MRI in patients at high-risk of developing hepatocellular carcinoma (HCC).In the determination of LI-RADS categories, ancillary features that may favor HCC or benignity may be applied to adjust categories. The latest LI-RADS
incorporates gadoxetic acid-enhanced MRI into the diagnostic algorithm of HCC, and hepatobiliary phase (HBP) specific features has been included in the ancillary features.
Purpose
To evaluate the effects
of ancillary features of gadoxetic acid-enhanced MRI on the categorization of HCCs using the latest LI-RADS (v2014).
Materials and Methods
This retrospective study
was approved by our institutional review board and the requirement for informed
consent was waived. We included 201 patients at high-risk for developing HCCs with 239
pathologically-confirmed HCCs which were detectable on gadoxetic acid-enhanced MRI. Two
independent radiologists assigned LI-RADS categorization before and after
applying ancillary features without and with HBP features, respectively. Frequencies of changing LI-RADS categories according
to ancillary features were investigated.
Definition of LI-RADS category
LR-1: definitely benign
LR-2: probably benign
LR-3: intermediate probability for HCC
LR-4: probably HCC
LR-5: definitely HCC
LR-5v: definitely HCC with tumor in vein
LR-M: probable malignancy, not specific for HCC
Results
On gadoxetic
acid-enhanced MRI, sensitivities of final categories of LR-5/5V in the
diagnosis of HCCs in reviewers 1 and 2 were 69.0% and 67.8%, respectively.
Interobserver agreement of LR-3~5/5V assignment was almost perfect (weighted
kappa = 0.810). When comparing LI-RADS categories before and after applying ancillary features,
14.2% and 10.0% of HCCs were changed their categories in reviewers 1 and 2,
respectively (LR-3 to LR-4: 14.2% and 9.6%; and LR-4 to LR-3: 0% and 0.4%).
Among ancillary features,
HBP signal intensity affected the adjustment of category in 3.3% and 2.9% of
cases, respectively.
Conclusion
LI-RADS categorization of HCCs on gadoxetic acid-enhanced MRI showed good interobserver agreement, and ancillary features including HBP features would frequently upgrade LR-3 into LR-4.
Acknowledgements
No acknowledgement found.References
1. LI-RADS v2014, http://nrdr.acr.org/lirads/
2. Mitchell
DG, Bruix J, Sherman M, Sirlin CB. LI-RADS (Liver Imaging Reporting and Data
System): summary, discussion, and consensus of the LI-RADS Management Working
Group and future directions. Hepatology 2015;61:1056-1065.
3. Hope
TA, Fowler KJ, Sirlin CB, Costa EA, Yee J, Yeh BM, et al. Hepatobiliary agents
and their role in LI-RADS. Abdom Imaging 2015;40:613-625.
4. Shah
A, Tang A, Santillan C, Sirlin C. Cirrhotic liver: What's that nodule? The
LI-RADS approach. J Magn Reson Imaging 2015.
5. Choi
JY, Lee JM, Sirlin CB. CT and MR imaging diagnosis and staging of
hepatocellular carcinoma: part II. Extracellular agents, hepatobiliary agents,
and ancillary imaging features. Radiology 2014;273:30-50.