Dynamic Contrast Enhanced MRI (DCE-MRI),
based on repeated imaging of the same few MRI slices with a few seconds’ interval after intravenous contrast injection,
correlates closely to histological inflammatory activity and is a promising tool to assess the early response to treatment,
potentially before volume changes and changes in OMERACT RAMRIS scores occur.
Analysis of DCE-MRI is usually done by manual selection of areas with most enhancement regions of interest (ROI),
but variable ROI...
Methods and Materials
DCE-MRI data were acquired in wrists of 50 RA patients and 5 controls by repeatedly obtaining 3 axial or coronal T1-weighted images every 10-15 seconds immediately after iv 0.2 mmol/kg Gd-DTPA (Magnevist),
using a 0.2T Esaote C-scan or E-scan (22-30 repetitions). DCE MRI protocol C-scan:Spin Echo 0.2T Coil: Dedicated WRIST coil No.
Slices /Image plane : Three 5mm axial wrist slices perpendicular to the radius with 0.3mm interslice gap,
starting at the tip of the ulna Sequence: TE 16, TR 100,...
Motion artefacts in all 3 planes were reduced from 1.3mm±7mm to 1mm±1.5mm shift and 7±6degree to 1±0.4degree rotation. SNR was increased by a factor 3 on average ,
image blurring was reduced and variations in the shape of dynamic curves extracted from the ROIs was reduced (figure 1). This reduced variation in measurements of ME and IRE (statistical f-test was applied).
the IRE was reduced from 0.21±0.1 to 0.12±0.02 [%/sec] and in ME from 0.35±0.23 to 0.1±0.01 [%].
Elimination of motion artefacts significantly reduced artefactual enhancement and increased SNR up to a factor 3.
Reduced variation in ROI measurements significantly influenced the accuracy of quantitative analysis of inflammation.
This supports the use of DCE-MRI augmented by motion reduction algorithms for more robust and valid analysis of synovitis in RA patients.
1) McQueen FM,
Dynamic gadolinium-enhanced magnetic resonance imaging of the wrist in patients with rheumatoid arthritis: comment on the article by Cimmino et al.
2004 Feb;50(2):674-5; author reply 675-6.
PubMed PMID: 14872514. 2) Kubassova O,
Fast and robust analysis of dynamic contrast enhanced MRI datasets.
Med Image Comput Comput Assist Interv.