Magnetic Resonance Imaging Is More Sensitive Than Radiographs in Detecting Change in Size of Erosions in Rheumatoid Arthritis
TIMOTHY S. CHEN, JOHN V. CRUES III, MUHAMMAD ALI, and ORRIN M. TROUM
Objective. To evaluate the technological performance of magnetic resonance imaging (MRI) with respect to projection radiography by determining the incidence of changes in the size of individual bone lesions in inflammatory arthritis, using serial high-resolution in-office MRI over short time intervals (8 months average followup), and by comparing the sensitivity of 3-view projection radiography with in-office MRI for detecting changes in size and number of individual erosions.
Methods. MR examinations of the wrists and second and third metacarpophalangeal joints were performed using a portable in-office MR system in a total of 405 patients with inflammatory arthritis, from one rheumatologist's practice, who were undergoing aggressive disease modifying antirheumatic drug therapy. Of the patients, 156 were imaged at least twice, allowing evaluation of 246 followup examinations (mean followup interval of 8 months over a 2-year period). Baseline and followup plain radiographs were obtained in 165 patient intervals. Patients refused radiographic examination on 81 followup visits.
Results. MRI demonstrated no detectable changes in 124 of the 246 (50%) followup MRI examinations. An increase in the size or number of erosions was demonstrated in 74 (30%) examinations, a decrease in the size or number of erosions in 36 (15%), and both increases and decreases in erosions were seen in 11 (4%). In the 165 studies with followup radiographic comparisons, only one examination (0.8%) showed an erosion not seen on the prior examination and one (0.8%) showed an increase in a previously noted erosion.
Conclusion. We showed that high-resolution in-office MRI with an average followup of 8 months detects changes in bony disease in 50% of compliant patients during aggressive treatment for inflammatory arthritis in a single rheumatologist's office practice. Plain radiography is insensitive for detecting changes in bone erosions for this patient population in this time frame. (First Release Aug 1 2006; J Rheumatol 2006;33:1957-67)
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From Radnet Management, Los Angeles; and Orrin M. Troum, MD and Medical Associates, Santa Monica, California, USA.
Drs. Crues and Troum own stock (less than 1% of outstanding shares) in MagneVu Inc. These shares have no monetary value at present.
Supported in part by a grant from the Centocor Division of Johnson & Johnson and from Radnet Management, a subsidiary of Primedex Health Systems.
T.S. Chen, MD, Radnet Management; J.V. Crues, MD, Radnet Management and Volunteer Clinical Professor, University of California, San Diego, School of Medicine; M. Ali, MD, Radnet Management; O.M. Troum, MD, Orrin M. Troum, MD and Medical Associates and Clinical Professor, Keck School of Medicine.
Address reprint requests to Dr. J. Crues, Radnet Management, 1516 Cotner Ave., Los Angeles, California 90025, USA. E-mail: firstname.lastname@example.org
Accepted for publication April 7, 2006.