RESEARCH - Are bone erosions detected by MRI and US true erosions?

[Guest guest]

Research article

Are bone erosions detected by magnetic resonance imaging and ultrasonography

true erosions? A comparison with computed tomography in rheumatoid arthritis

metacarpophalangeal joints

Uffe Møller Døhn1 , Bo J Ejbjerg1 , Michel Court-Payen2 ,

Hasselquist3 , Eva Narvestad2 , Marcin Szkudlarek1 , Jakob M Møller3 ,

Henrik S Thomsen3 and Mikkel Østergaard1 ,4

1Department of Rheumatology, University of Copenhagen Hvidovre Hospital,

Hvidovre, Denmark

2Department of Radiology, University of Copenhagen Rigshospitalet,

Copenhagen, Denmark

3Department of Diagnostic Radiology, University of Copenhagen Herlev

Hospital, Herlev, Denmark

4Department of Rheumatology, University of Copenhagen Herlev Hospital,

Herlev, Denmark

Arthritis Research & Therapy 2006, 8:R110 doi:10.1186/ar1995

Published 18 July 2006

Abstract

The objective of the study was, with multidetector computed tomography (CT)

as the reference method, to determine whether bone erosions in rheumatoid

arthritis (RA) metacarpophalangeal (MCP) joints detected with magnetic

resonance imaging (MRI) and ultrasonography (US), but not with radiography,

represent true erosive changes. We included 17 RA patients with at least

one, previously detected, radiographically invisible MCP joint MRI erosion,

and four healthy control individuals. They all underwent CT, MRI, US and

radiography of the 2nd to 5th MCP joints of one hand on the same day. Each

imaging modality was evaluated for the presence of bone erosions in each MCP

joint quadrant. In total, 336 quadrants were examined. The sensitivity,

specificity and accuracy, respectively, for detecting bone erosions (with CT

as the reference method) were 19%, 100% and 81% for radiography; 68%, 96%

and 89% for MRI; and 42%, 91% and 80% for US. When the 16 quadrants with

radiographic erosions were excluded from the analysis, similar values for

MRI (65%, 96% and 90%) and US (30%, 92% and 80%) were obtained. CT and MRI

detected at least one erosion in all patients but none in control

individuals. US detected at least one erosion in 15 patients, however,

erosion-like changes were seen on US in all control individuals. Nine

patients had no erosions on radiography. In conclusion, with CT as the

reference method, MRI and US exhibited high specificities (96% and 91%,

respectively) in detecting bone erosions in RA MCP joints, even in the

radiographically non-erosive joints (96% and 92%). The moderate

sensitivities indicate that even more erosions than are seen on MRI and,

particularly, US are present. Radiography exhibited high specificity (100%)

but low sensitivity (19%). The present study strongly indicates that bone

erosions, detected with MRI and US in RA patients, represent a loss of

calcified tissue with cortical destruction, and therefore can be considered

true bone erosions.

http://arthritis-research.com/content/8/4/R110/abstract

Not an MD

I'll tell you where to go!

Mayo Clinic in Rochester

http://www.mayoclinic.org/rochester

s Hopkins Medicine

http://www.hopkinsmedicine.org