Interpreting Therapeutic Effect in Multiple Sclerosis via MRI Contrast Enhancing Lesions: Now You See Them, Now You Don't

J Neurol. 2014 Apr;261(4):809-16. doi: 10.1007/s00415-014-7284-0. Epub 2014 Feb 26.

Abstract

Gadolinium (Gd) enhancement of multiple sclerosis (MS) lesions on MRI scans is a commonly used outcome measure in therapeutic trials. However, enhancement depends on MRI acquisition parameters that might significantly alter detectability. We investigated how the difference in blood-brain barrier (BBB) permeability threshold between MRI protocols affects lesion detection and apparent enhancement time using dynamic-contrast-enhanced (DCE) MRI. We examined fourty-four relapsing-remitting MS patients with two MRI protocols: 'standard sensitivity' (SS) (1.5 T, single-dose Gd) and 'high sensitivity' (HS) (3 T, triple-dose Gd, delayed acquisition). Eleven patients had at least one enhancing lesion and completed the 1-month follow-up. We acquired DCE-MRI during the HS protocol and calculated BBB permeability. Sixty-five lesions were enhanced with the SS vs. 135 with the HS protocol. The detection threshold of the HS was significantly lower than that of the SS protocol (K trans = 2.64 vs. 4.00E-3 min(-1), p < 0.01). Most lesions (74 %) were in the recovery phase; none were in the onset phase and 26 % were at the peak of enhancement. The estimated duration of detectability with the HS protocol was significantly longer than for the SS protocol (6-12 weeks vs. 3 weeks). Our observations on the protocol-dependent threshold for detection and time-course help explain discrepancies in the observed effects of anti-inflammatory therapies on MS lesions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Algorithms
  • Contrast Media
  • Female
  • Gadolinium
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging / methods*
  • Male
  • Multiple Sclerosis, Relapsing-Remitting / diagnosis*
  • Multiple Sclerosis, Relapsing-Remitting / drug therapy*
  • Signal-To-Noise Ratio
  • Young Adult

Substances

  • Contrast Media
  • Gadolinium