Aim: Use of postcontrast T1-weighted imaging (WI) is an important tool in diagnosing and predicting the course of multiple sclerosis (MS). Application of optimized imaging strategies has the potential to increase detection of magnetic resonance imaging (MRI) disease activity. This study investigated the superiority of the 3T optimized vs. the 1.5T standardized protocols in detecting gadolinium enhancing (GD-E) lesions in patients with MS.
Methods: A standard protocol was defined as a 1.5T scan with a single-dose of Gd and a 5-minute scanning delay after injection. An optimized protocol was defined as a 3T MRI scan, using a triple dose of Gd, 20 min scan delay, and using an off-resonance saturated magnetization transfer pulse to reduce the background signal. Fourteen relapsing-remitting MS patients and 3 healthy controls (HC) were scanned with 1.5T standardized and a 3T optimized protocols in random order over 72 hours.
Results: There were 47 Gd-E lesions in the MS patients on 3T optimized and 34 on 1.5T standard protocols, a 38.2% increase. There was a significant increase in Gd-enhanced lesion volume (LV) detected with the optimized protocol (179.6%, P<0.05), with 94.6% of the mean Gd-enhanced LV detected only on the 3T optimized protocol. No Gd-E lesions were detected in HC on either protocol.
Conclusion: The 3T optimized protocol is a useful technique for increasing sensitivity of MRI to detect Gd-E lesions.