European Journal of Radiology 66 (2008) 65–74 Focal liver lesions: Whether a standard dose (0.05 mmol/kg) gadobenate dimeglumine can provide the same diagnostic data as the 0.1 mmol/kg dose Mehmet Selim Nural, Erkan Gokce, Murat Danaci, Ilkay Koray Bayrak ∗ , H. Baris Diren Ondokuz Mayis University, Faculty of Medicine, Department of Radiology, Samsun, Turkey Received 15 November 2006; received in revised form 19 April 2007; accepted 24 April 2007 Abstract Objective: Gadobenate dimeglumine (Gd-BOPTA) is a liver-specific contrast agent also showing a distribution in the extracellular compartment which is recommended to be used at standard dose (0.05mmol/kg) in magnetic resonance imaging (MRI) of liver lesions. However, its use at 0.1 mmol/kg is gradually increasing in recent clinical practice. Which dose should we use in routine MRI of liver lesions from now on? This study investigated the efficacy of Gd-BOPTA at a standard dose versus 0.1 mmol/kg dose in demonstrating diagnostic data in MRI of focal liver lesions. Materials and methods: The study included 47 patients with focal liver lesions. Twenty-two patients received standard dose and 25 patients received 0.1mmol/kg dose Gd-BOPTA intravenously. MRI of both groups was carried out with T1-A FLASH-2D and T2-A TURBO spin echo before contrast injection and T1-A FLASH-2D sequences in dynamic and late phase (90th minute) after the contrast injection. The lesion conspicuity for each image was evaluated qualitatively. Liver signal to noise ratio (SNR), absolute lesion-liver contrast to noise ratio (CNR), mean lesion-liver CNR and contrast enhancement rate of the liver obtained from both groups were compared quantitatively. Results: While liver contrast enhancement rate in the group receiving standard dose Gd-BOPTA were 41% ± 42 in the arterial phase, 66% ± 58 in the portal phase, 45% ± 45 in the venous phase and 42% ± 88 in the late phase, these values were 43% ± 59, 86% ± 73, 63% ± 75 and 61% ± 105, respectively, in the group receiving the dose of 0.1 mmol/kg. There were no statistically significant differences between the means of both groups. While the absolute lesion-liver CNR values were 18 ± 15 precontrast, 22 ± 18 in the arterial phase, 19 ± 17 in the portal phase, 15 ± 10 in the venous phase and 24 ± 26 in the late phase in the group receiving the standard dose Gd-BOPTA, these values were 13 ± 11, 18 ± 15, 15 ± 15, 13 ± 13 and 19 ± 21, respectively, in the group receiving the 0.1mmol/kg dose. There were no statistically significant differences between the means of both groups (p >0.05). However, when the mean lesion-liver CNR values were compared, there was statistically significant difference between each arterial and portal phases of metastases in both groups (p < 0.05). There was no statistical difference found in other lesions. When lesion conspicuity scores were compared, there were no significant differences between the two groups. Conclusion: In liver lesions, similar diagnostic data are obtained in dynamic and late phase MRI with either standard dose Gd-BOPTA or with a dose of 0.1 mmol/kg. Because there was a difference in only metastases in both groups, in oncological patients who are being investigated for liver metastasis, it is expedient to use a dose of 0.1 mmol/kg. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Gadobenate dimeglumine; Focal liver lesions; Magnetic resonance imaging Dynamic examinations have a very important role in detect- ing lesions and determining characterization in liver pathologies. However, since various lesions show similar behavior and contrast enhancement characteristics for both with computer tomography (CT) and magnetic resonance imaging (MRI), it is not always possible to fully identify the structure and nature of some lesions. In order to obtain more information about the lesions, liver-specific contrast media (hepatocyte-specific ∗ Corresponding author. Tel.: +90 5332652896; fax: +90 362 4576041. E-mail address: ilkaykoray@hotmail.com (I.K. Bayrak). manganese dipyridoxal diphosphonate and reticuloendothelial- specific superparamagnetic iron oxide) have been developed [1–3]. Because these contrast media take time to reach the rel- evant cells, dynamic examinations cannot be carried out and lesion characterization only depends on the difference between the lesion and the liver [1,4]. Gadobenate dimeglumine (Gd-BOPTA) and gadolinium- ethoxybenzyl-diethylentriamine pentaacetic acid (Gd-EOB- DTPA) are contrast agents with extra-cellular distribution and taken up by hepatocytes. The use of Gd-EOB-DTPA in the liver is approved in many countries. It is eliminated by uri- nary system and biliary system (42–51% and 43–53% of the 0720-048X/$ – see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrad.2007.04.022