Improved characterization of focal liver lesions with liver-specific gadoxetic acid disodium-enhanced magnetic resonance imaging: a multicenter phase 3 clinical trial

Abstract

Objectives: To evaluate the safety of gadoxetic acid disodium (Gd-EOB-DTPA) magnetic resonance imaging (MRI) and its efficacy in characterizing liver lesions.

Methods: Lesion characterization and classification using combined (unenhanced and Gd-EOB-DTPA-enhanced) MRI were compared with those using unenhanced MRI and contrast-enhanced spiral computed tomography (CT) using on-site clinical and off-site blinded evaluations for patients with focal liver lesions.

Results: Gadoxetic acid disodium was well tolerated in this study. For the clinical evaluation, more lesions were correctly characterized using combined (unenhanced and Gd-EOB-DTPA-enhanced) MRI than using unenhanced MRI and spiral CT (96% vs 84% and 85%, respectively; P < or = 0.0008). For the blinded evaluation, more lesions were correctly characterized using combined MRI compared with using unenhanced MRI (61%-76% vs 48%-65%, respectively; P < or = 0.0012 for 2/3 readers); when compared with spiral CT, a similar proportion of lesions were correctly characterized.

Conclusions: Gadoxetic acid disodium-enhanced MRI is of clinical benefit relative to unenhanced MRI and spiral CT for a radiological diagnosis of liver lesions.

FIGURE 1

Focal nodular hyperplasia in a female patient aged 47 years. Using dual-phase helical CT, a segment 2 lesion enhances avidly in the arterial phase (A) and becomes isodense to the liver in the portal venous phase (B). No discrete scar was present on this or several other similar lesions (not shown), and the lesions were incorrectly interpreted as hypervascular metastases on blinded reading. Using unenhanced MRI, the lesion was of intermediate hyperintensity on the T2W images with hyperintense central scar (C) and mild hyperintensity on the T1W images (D). Using dynamic Gd-EOB-DTPA–enhanced sequences, the lesions also enhanced avidly in the late arterial phase (E) with enhancement of the central scar in the portal venous phases (F). At 20 minutes after injection, the hepatocellular lesion retains contrast (G). The other lesions also showed similar characteristics and were correctly interpreted as focal nodular hyperplasia on blinded reading of combined images.

FIGURE 2

Hemangiomas in a female patient aged 30 years. Using dual-phase helical CT, nodular peripheral enhancement is present in a segment 4 lesion in the arterial phase (A) with progressive enhancement in the portal venous phase (B). Other similar lesions (not shown) were present with similar features, and the lesions were interpreted as hemangiomas on blinded reading. Using unenhanced MRI, the lesion was uniformly and markedly hyperintense on T2W images (C) and hypointense on T1W images (D) and interpreted as a simple cyst. Using dynamic Gd-EOB-DTPA–enhanced sequences, the lesions also showed characteristic progressive nodular peripheral enhancement in the late arterial (E) and portal venous phases (F). At 20 minutes after injection, the lesion signal has decreased in comparison with the background liver (G). Based on combined images, the lesions were interpreted as hemangiomas.

FIGURE 3

Hepatocellular carcinoma in a male patient aged 75 years with proven histopathology. Using dual-phase helical CT, a segment 7 mass markedly enhances compared with the liver (A) and then rapidly becomes isointense with capsular enhancement in the portal venous phase (B). The mass was interpreted as a hepatocellular carcinoma on blinded reading. On unenhanced MRI, the mass was of intermediate hyperintensity on the T2W images (C) and hypointense on the T1W images (D) and interpreted as a hemangioma. Using dynamic Gd-EOB-DTPA–enhanced sequences, the mass enhanced avidly relative to liver late arterial phase (E) and then unenhanced with delayed capsular enhancement in the late portal venous phase (F). At 20 minutes after injection, the lesion signal was hypointense in comparison to the background liver (G). Using combined images, the lesion was interpreted as a hepatocellular carcinoma. Overall confidence of characterization was stronger for combined images relative to the CT images alone.