The Early‐Enhancing Hepatic Vein: Differentiating Focal Nodular Hyperplasia and Hepatic Adenoma With Pathologic Validation in MRI

Abstract

BackgroundFocal nodular hyperplasia (FNH) and hepatic adenoma (HA) are two common benign liver lesions with different management options. In particular, resection is considered for large HA lesions to avoid possible bleeding complications or rarely malignant degeneration.PurposeTo determine whether early enhancement of a draining hepatic vein (EDHV) and absence of perilesional enhancement (PLE) on arterial phase MR images are useful for distinguishing FNH from HA.Study TypeRetrospective.PopulationA total of 34 patients: 16 with FNH and 18 with HA lesions.Field Strength/SequenceA1.5 T, axial T1 fat‐suppressed arterial postcontrast.AssesmentFour abdominal radiologists blinded to pathologic diagnosis assessed for the presence or absence of EDHV in association with the lesion, definitively characterized by pathology. This was considered present if contrast could be identified in a hepatic vein contiguous with the lesion in question. Secondarily, PLE was evaluated.Statistical TestsFleiss's multirater kappa statistic, Chi‐squared statistic, Phi‐coefficient. Significance level P < 0.05.ResultsConsidering all observations obtained from the four readers, an EDHV was identified with FNH 48.5% of the time. EDHV was seen with HA in 8.8% of cases. PLE was seen with significantly greater frequency in HA. The presence of an EDHV was associated with the absence of PLE.Data ConclusionIn a lesion that may be either an FNH or HA, confident identification on arterial phase images of an EDHV should lead the reader to favor FNH, while the presence PLE should dissuade the reader from FNH.Evidence Level4.Technical EfficacyStage 2.

Editorial for “The Early‐Enhancing Hepatic Vein: Differentiating Focal Nodular Hyperplasia and Hepatic Adenoma With Pathologic Validation in MRI”

“…So some studies utilized the 3D whole liver breath hold technique with the different acquisition of arterial phase. 4 The results demonstrated a significant correlation between the early draining vein and FHN, and a negative correlation with PLE. In clinical practice, almost all MRI machines enable to perform a standard technique with the multiphasing acquisition, although in uncooperative patients without contrast injection, the quality will be a problematic issue.…”

“…3 Unlike HCAs, hemorrhage and necrosis are rare in these lesions and are often discovered by chance, and usually require no treatment. 4,5 The most common diagnostic image-based modalities including ultrasound (US), computerized tomography (CT), and magnetic resonance imaging (MRI) are employed for initial and differential diagnostic purposes with nonspecific abdominal symptoms. 6 Although Doppler US is useful for vascular evaluations and outlines lobulations, central scars are only observed in 20% of cases with the use of US.…”

“…FNH lesions are generally lobulated and noncapsulated solitary lesions (80%) with diameters >5 cm 3 . Unlike HCAs, hemorrhage and necrosis are rare in these lesions and are often discovered by chance, and usually require no treatment 4,5 …”

“…Due to the early enhancement of the draining vein toward the hepatic portal vein in the MRI arterial phase, and no evidence of perilesional edema (PLE) in the arterial phase, timing is a very sensitive tool for this purpose. So some studies utilized the 3D whole liver breath hold technique with the different acquisition of arterial phase 4 . The results demonstrated a significant correlation between the early draining vein and FHN, and a negative correlation with PLE.…”