Multicenter, double-blind, randomized, intra-individual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine in MRI of brain tumors at 3 tesla

Abstract

Purpose: To prospectively compare 0.1 mmol/kg doses of gadobenate dimeglumine and gadopentetate dimeglumine for contrast-enhanced MRI of brain lesions at 3 Tesla (T).

Materials and methods: Forty-six randomized patients underwent a first examination with gadobenate dimeglumine (n = 23) or gadopentetate dimeglumine (n = 23) and then, after 2-7 days, a second examination with the other agent. Contrast administration (volume, rate), sequence parameters (T1wSE; T1wGRE), and interval between injection and image acquisition were identical for examinations in each patient. Three blinded neuroradiologists evaluated images qualitatively (lesion delineation, lesion enhancement, global preference) and quantitatively (lesion-to-brain ratio [LBR], contrast-to-noise ratio [CNR], % lesion enhancement). Differences were assessed using Wilcoxon's signed-rank test. Reader agreement was determined using kappa (kappa) statistics.

Results: There were no demographic differences between groups. The three readers preferred gadobenate dimeglumine globally in 22 (53.7%), 21 (51.2%), and 27 (65.9%) patients, respectively, compared with 0, 1, and 0 patients for gadopentetate dimeglumine. Similar significant (P < 0.001) preference was expressed for lesion border delineation and enhancement. Reader agreement was consistently good (kappa = 0.48-0.64). Significantly (P < 0.05) higher LBR (+43.5- 61.2%), CNR (+51.3-147.6%), and % lesion enhancement (+45.9-49.5%) was noted with gadobenate dimeglumine.

Conclusion: Brain lesion depiction at 3T is significantly improved with 0.1 mmol/kg gadobenate dimeglumine.

Figures

Figure 1

A 55-year-old woman with a grade IV posterior fossa astrocytoma infiltrating the brainstem. T1SE and T1GRE images acquired from 8 min after administration of 0.1 mmol/kg gadobenate dimeglumine and 0.1 mmol/kg gadopentetate dimeglumine. The tumor enhancement is considerably greater after the injection of gadobenate dimeglumine and as a consequence the demarcation from surrounding tissues is better.

Figure 2

A 59-year-old woman with metastatic disease from primary lung cancer. T1SE and T1GRE images acquired from 6 min after administration of 0.1 mmol/kg gadobenate dimeglumine and 0.1 mmol/kg gadopentetate dimeglumine. The single subcortical metastasis (arrow) is readily diagnosed with gadobenate dimeglumine but is barely visible after the injection of gadopentetate dimeglumine.

Figure 3

A 77-year-old man with bilateral frontoparietal extension of a glioblastoma. T1SE and T1GRE images acquired from 6 min after after administration of 0.1 mmol/kg gadobenate dimeglumine and 0.1 mmol/kg gadopentetate dimeglumine. Considerably greater contrast enhancement and better depiction of internal lesion morphology is apparent after injection of gadobenate dimeglumine.

Figure 4

Bar graphs showing significantly increased mean lesion-to-brain ratios (a) and contrast-to-noise ratios (b) with 0.1 mmol/kg gadobenate dimeglumine compared with 0.1 mmol/kg gadopentetate dimeglumine at 3T using both T1wSE and T1wGRE sequences. Data obtained from quantitative measurements of signal intensity enhancement for all patients at ROIs positioned by each of three blinded readers independently.