Focal nodular hyperplasia of the liver: assessment with contrast-enhanced TurboFLASH MR imaging.

Abstract

Twenty-two patients with 25 cases of focal nodular hyperplasia (FNH) proved with pathologic study were imaged with a TurboFLASH (fast low angle shot) sequence combined with bolus administration of gadolinium tetraazacyclododecanetetraacetic acid (DOTA), spin-echo (SE) T2-weighted sequences, and postcontrast T1-weighted sequences. FNH-liver signal-difference-to-noise ratios were quantified; the features of the central scar were qualitatively analyzed. On SE T2-weighted images, all FNHs were hyperintense; in two cases the central scar exhibited a high signal intensity associated with hypointense areas corresponding to fibrous tissue within the branches of the scar. Unenhanced TurboFLASH images always demonstrated the FNHs as hypointense and always depicted the central scar as a hypointense area within the lesion. After bolus injection, arterial enhancement of FNH was clearly seen, and in 10 of 25 lesions, enhancement within the scar was seen 40-80 seconds after injection. Both unenhanced and enhanced TurboFLASH sequences produced the best signal-difference-to-noise ratios in comparison with T2-weighted images.

A multicenter, randomized, double‐blind study to evaluate the safety, tolerability, and efficacy of OptiMARK (gadoversetamide injection) compared with Magnevist (gadopentetate dimeglumine) in patients with liver pathology: Results of a phase III clinical trial

“…During the arterial phase of contrast enhancement, the arterial contrast material arriving at normal liver is diluted 4:1 by unenhanced blood, but 100% of the flow to the neoplasm contains contrast material (23). Arterial phase images are thus quite useful for detecting hypervascular neoplasms such as hepatocellular carcinoma, focal nodular hyperplasia, hepatic adenomas, and hypervascular metastases (2,4,11,12,16,18). In these early phase images, such lesions will appear bright compared with the largely unenhanced liver parenchyma.…”

Imaging Modalities for Focal Nodular Hyperplasia and Hepatocellular Adenoma

“…A central scar, typically hyperintense, may be seen in approximately 30% of the lesions, mostly in the lesions >3 cm. On the T 1 images, most lesions are iso- or slightly hypointense while the central scar appears hypointense [39,40,41,42,43,44,45,46,47,48]. HCA is also mainly slightly hyper- to isointense on T 2 images.…”

Dynamic contrast-enhanced MR imaging of fibrolamellar hepatocellular carcinoma

“…This pattern of enhancement demonstrates considerable and potentially confusing overlap with previously described patterns associated with other hepatic neoplasms. Immediate diffuse enhancement with rapid equalization to liver has also been described in cases of FNH, hepatic adenoma, HCC, and hypervascular metastasis [8,9]. If images are not obtained immediately after contrast administration, the appearance of FL-HCC which rapidly becomes more homogeneous and isointense to liver may be indistinguishable from these other hepatic neoplasms.…”

“…Hemangiomas also enhance in a pathognomonic peripheral nodular fashion with progressive fill-in and high signal intensity on delayed images [11]. In contrast to the scars seen in FL-HCC, central scars seen in FNH and, rarely, well-differentiated HCC may appear hyperintense on T2SE images and demonstrate contrast enhancement [8]. Enhancement of the scar in FNH may only be seen on delayed images [12].…”