Dark rim on gray matter–double inversion recovery
Another promising imaging technique, developed by researchers at the Mayo Clinic, was found to enhance diagnostic specificity in MS (). Using a novel double inversion recovery sequence that suppresses cerebrospinal fluid and gray matter signal (GM–double inversion recovery), they compared white matter lesions in a group of 107 MS patients and in a second group of 36 positive controls with white matter lesions who did not have a diagnosis of MS. In patients with MS lesions, 35% had a dark rim visible on GM–double inversion recovery, compared with only 1% of the positive control group. Dark rims were associated with a decrease in the lesion T1 ratio. “We need a larger prospective study to see how this pans out,” Dr. Solomon said.
Evaluation of lesion morphology also holds promise. In one recent study, researchers performed standardized 3T 3-D brain MRI studies on 19 MS patients and 11 patients with nonspecific white matter (NSWM) disease (). They identified focal supratentorial lesions, used maximum intensity projection to reconstruct them, and created 3-D printed models. The models were randomly evaluated by three blinded raters who scored lesions based on symmetry (symmetrical or asymmetrical), surface morphology (simple or complex), and a long list of secondary characteristics. In all, the researchers evaluated 1,001 supratentorial lesions, including 710 in MS patients and 291 in patients with NSWM disease.
MS vs. NSWM disease lesions had a higher percentage of asymmetry (75.9% vs. 43%; odds ratio, 4.39; P less than .001); complex surface morphologies (65.9% vs. 27.8%; OR, 2.3; P less than .001); multilobular lesions (11% vs. 3%; P less than .001), and elongated lesion (12.8% vs. 2.4%; P less than .001). “This is interesting, but it was a small study,” Dr. Solomon said. “We need to look at this in other diagnoses, and we need prospective data.”
Dr. Solomon disclosed that he has received consulting fees from EMD Serono and research funding from Biogen. He has also performed contracted research for Biogen, Novartis, Actelion, and Genentech/Roche.