MRI may be superior to clinical assessment in detecting morphea activity

MRI may be more sensitive in detecting morphea disease activity than clinical assessment, according to a research letter.

A cross-sectional analysis included 20 consecutive patients with suspected deep morphea from the Morphea in Adults and Children cohort. The researchers defined morphea as “deeply sclerotic, poorly circumscribed plaques, indicating possible involvement of soft tissue,” according to the findings.

Linear morphea was reported in 70% of the cohort, which was 65% white and 75% women.

The analysis included 27 MRI examinations. When these images were taken, 44% of patients were being treated with methotrexate, 11% with mycophenolate mofetil, 4% with topical triamcinolone and 41% with no therapy.

MRI results confirmed clinical suspicion that soft tissue was involved in 26 of the 27 available scans. Muscle and/or deep fascia involvement was observed in seven of the scans. In addition, induration, which the researchers noted is a component of the Localized Scleroderma Cutaneous Assessment Tool (LoSCAT) score, was present in six of the seven (86%) MRI results of patients with fascia or muscle involvement. By comparison, induration was present in just five of 20 (25%) scans from patients who did not have fascia or muscle involvement (P = .005). Similarly, median Physician Global Assessment of Disease Activity (PGA-A) scores were 37 (interquartile range, 22-48) for the fascia/muscle involvement group and 0 (IQR, 0-23; P = .02) for those without that involvement.

Clinicians suspected clinically active disease in 15 patients. MRI showed clinically active disease in 17 patients.

In five patients, MRI revealed disease activity where none was observed in the clinic.

Higher PGA-A scores also were reported among patients with active disease on MRI compared with those who demonstrated no active disease on MRI, 25 (IQR, 2-37) vs. 0 (IQR, 0-2) (P = .007). However, this trend was not observed for the modified Localized Scleroderma Skin Severity Index (mLoSSI) score.

Other MRI findings showed that lesions extended beyond clinical margins by a mean length of 6.3 cm.

The researchers added that Cohen’s kappa ranged from 0.780 to 1.000, which they suggested indicates “substantial to near-perfect agreement.”

Discrepancies between clinical and MRI assessments “highlight potential misclassification of lesions as inactive when using the mLoSSI alone, particularly in deep morphea, in which activity is difficult to detect,” the researchers said. “Interestingly, palpable peripheral induration, a component of the mLoSSI, best reflected inflammation in MRI results, which suggests induration is a sign of activity in deeper tissues where erythema is not visible.”

In an accompanying editorial, Carla N. Cruz-Diaz, MD, and Anna K. Haemel, MD, both of the department of dermatology at the University of California, San Francisco, suggested that these findings are important because misclassification of disease activity may lead to patients being excluded from treatment.

“Nevertheless, this study had a small sample size and compared [two] different modalities, [one] of which was a validated clinical score in morphea (the LoSCAT) and the other was not (MRI),” they wrote. “Further studies are needed to clarify the prognostic and treatment implications of disease activity noted on MRI in the absence of clinically apparent morphea activity.”

They added that the findings support the use of MRI in this patient population, which underscores similar findings from other such studies. – by Rob Volansky

Disclosures: Abbas and Cruz-Diaz report no relevant financial disclosures. Please see the reports for all other authors’ relevant financial disclosures.