¹⁸ F-FDG PET/MR imaging in patients with suspected liver lesions: Value of liver-specific contrast agent Gadobenate dimeglumine

by Julian Kirchner, Lino M. Sawicki, Cornelius Deuschl, Johannes Grüneisen, Karsten Beiderwellen, Thomas C. Lauenstein, Ken Herrmann, Michael Forsting, Philipp Heusch, Lale Umutlu

To evaluate the added value of the application of the liver-specific contrast phase of Gadobenate dimeglumine (Gd-BOPTA) for detection and characterization of liver lesions in ¹⁸F-FDG PET/MRI.

41 patients with histologically confirmed solid tumors and known / suspected liver metastases or not classifiable lesions in ¹⁸F-FDG PET/CT were included in this study. All patients underwent a subsequent Gd-BOPTA enhanced ¹⁸F-FDG PET/MRI examination. MRI without liver-specific contrast phase (MRI₁), MRI with liver-specific contrast phase (MRI₂), ¹⁸F-FDG PET/MRI without liver-specific contrast phase (PET/MRI₁) and with liver-specific contrast phase (PET/MRI₂) were separately evaluated for suspect lesions regarding lesion dignity, characterization, conspicuity and confidence.

PET/MRI datasets enabled correct identification of 18/18 patients with malignant lesions; MRI datasets correctly identified 17/18 patients. On a lesion-based analysis PET/MRI₂ provided highest accuracy for differentiation of lesions into malignant and benign lesions of 98% and 100%. Respective values were 95% and 100% for PET/MRI₁, 93% and 96% for MRI₂ and 91% and 93% for MRI₁. Statistically significant higher diagnostic confidence was found for PET/MRI₂ and MRI₂ datasets compared to PET/MRI₁ and MRI_1, respectively (p < 0.001).

The application of the liver-specific contrast phase in ¹⁸F-FDG PET/MRI further increases the diagnostic accuracy and diagnostic confidence for correct assessment of benign and malignant liver lesions.