Comparison between immediate and delayed imaging after gadolinium chelate injection for detecting enhanced lesions in multiple sclerosis

Magnetic resonance imaging is a noninvasive and valuable method in the diagnosis of Multiple Sclerosis. Compared with other modalities, the sensitivity of Magnetic resonance imaging for detection of the lesion increases using magnetization transfer and delayed imaging. Our aim was to compare the two methods in detecting Multiple Sclerosis lesions. Patients and Methods: In this double-blind clinical trial, twenty-one patients with the definite diagnosis of Multiple Sclerosis referred to Poursina Hospital, Rasht were included. Two radiologists evaluated all the images. First, images without contrast were conducted, then 0.1 mmol/kg contrast material (Dotarem, single dose) was injected and after 30 minutes, T1W and magnetization transfer images were obtained. Seventy-two hours later, T1W images were obtained immediately after injection of 0.2 mmol/kg contrast material (double dose). The data were analyzed using Fisher's and McNemar tests by SPSS for Windows. Results: Delayed magnetization transfer showed 44 enhanced lesions using magnetization transfer (69.84%) and 29 lesions using T1 (46.03%). In addition, the number of enhanced lesions in the delayed method were significantly more than those in the immediate method (p value=0.003). Conclusion: The use of single dose in combination with magnetization transfer and delayed images after 20-30 minutes enables us to detect more enhanced lesions.