Hepatobiliary-phase hypointensity showed high interreader agreement among radiologists evaluating liver observations with LI-RADS CT/MRI (v2018) ancillary features (AFs) -- particularly those suggesting malignancy, researchers have found.
The results could have direct implications for how LI-RADS CT/MRI (v2018) should be applied in clinical liver imaging practice, according to a team led by Yong Jun Jung, MD, of the University of Ulsan College of Medicine in Seoul, South Korea. The study findings were published April 22 in the American Journal of Roentgenology.
"Interreader agreement was generally higher for AFs favoring malignancy than for those favoring benignity," the group noted.
In LI-RADS CT/MRI (v2018), AFs support observation characterization and category assignment, it explained. Unfortunately, there isn't much research regarding interreader agreement across the range of AFs.
To address this gap, Jung and colleagues conducted a review and meta-analysis of interreader agreement of all individual AFs in LI-RADS CT/MRI (v2018), identifying factors associated with interpretation variability. They searched Medline, Embase, and Cochrane databases for original research studies published between January 2018 and September 2025 that reported interreader agreement in these LI-RADS frameworks. Final analysis included 47 studies that represented 11,891 patients and 13,695 hepatic observations.
The team found that AFs favoring malignancy had higher interreader agreement than those that appeared benign:
Interreader agreement for individual ancillary features in LI-RADS CT/MRI (v2018) | |
Ancillary features (AFs) by type | Pooled kappa value |
AFs favoring malignancy but not HCC | |
| Hepatobiliary-phase hypointensity | 0.84 |
| Mild–moderate T2 hyperintensity | 0.77 |
| Restricted diffusion | 0.75 |
| Iron sparing in solid mass | 0.72 |
| Transitional-phase hypointensity | 0.70 |
| Fat sparing in solid mass | 0.69 |
| Corona enhancement | 0.63 |
| Subthreshold growth | 0.58 |
AFs favoring HCC | |
| Blood products in mass | 0.75 |
| Fat in mass more than adjacent liver | 0.72 |
| Mosaic architecture | 0.69 |
| Nodule-in-nodule appearance | 0.66 |
| Nonenhancing capsule | 0.58 |
AFs favoring benignity | |
| Iron in mass more than liver | 0.73 |
| Undistorted vessels | 0.60 |
| Marked T2 hyperintensity | 0.59 |
| Hepatobiliary-phase isointensity | 0.58 |
| Enhancement paralleling blood pool | 0.26 |
The finding that AFs suggesting benignity showed markedly lower agreement could have implications for how in LI-RADS CT/MRI (v2018) should be applied in clinical liver imaging practice, the group suggested, noting that the lower reproducibility of benignity-favoring features likely reflects their rarity in clinical practice, as they appear in only 1% to 3% of cases.
"Cautious application of AFs in clinical practice is advised for the AFs associated with low agreement, particularly in the settings further contributing to reduced agreement," the team concluded.
Access the full review here.
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
