Gadoteridol in multiple sclerosis patients - A comparison of single and triple dose with immediate vs. delayed imaging

Enhancement of lesions in multiple sclerosis (MS) has been investigated usi ng standard and high doses of gadolinium. The purposes of this study are to compare the relative merits of single and triple dose as well as examine t he merits of delayed triple-dose images in a large group of patients. Thirt y-seven patients with multiple sclerosis underwent contrast enhanced brain magnetic resonance imaging (MRI). After noncontrast images, a single dose ( 0.1 mmol/kg) of gadoteridol was administered. Subsequently, axial T1-weight ed images were obtained immediately after administration, and again after a delay of approximately 20 minutes. After an additional 0.2-mmol/kg dose wa s administered, to provide a total cumulative dose of 0.3 mmol/kg of gadote ridol, immediate and delayed axial T1-weighted image sequences were repeate d. The contrast-noise ratio (C/N) was calculated fbr each identified, enhan cing lesion in each series, Furthermore, blinded readings were performed to determine the lesion detection rate, Of the forty definite lesions that un derwent all four sequences, triple-dose delayed images exhibited the highes t contrast-noise ratio in a significantly larger number of lesions (p< 0.00 01). Triple-dose immediate and delayed scans resulted in significantly high er contrast-noise ratios (6.47 and 9.99, respectively when compared with, t hose of the single dose scans (3.4 for immediate scans and 5.24 for delayed ) (p < 0.01). The lesion detection rate was highest for triple dose delayed (95%), followed by triple-dose immediate (83%), single-dose delayed (68%) and finally, single-dose immediate scans (43%). Triple-dose immediate was n oted to have a significantly increased (p < 0.0002) lesion detection rate w ith respect to the standard-dose immediate scans and standard-dose delayed scans (p < 0.02). In four lesions (10% of the total number of lesions), det ection occurred only with the triple-dose delayed image sequence. Triple-do se 0.3 mmol/kg gadolinium with delayed imaging resulted in the highest lesi on conspicuity and the highest lesion identification rate. There was a tren d of progressively increasing defection rates from single-dose immediate sc ans to triple-dose delayed scans. Triple-dose delayed scans resulted in sig nificantly higher (p < 2 x 10(-8)) contrast noise ratios than all other seq uences of this study. (C) Elsevier Science Inc., 1998.