A Cross-sectional Comparison of Magnetic Resonance Imaging Findings and Clinical Assessment in Patients With Morphea

Abstract

This cross-sectional analysis compares clinical assessment with magnetic resonance imaging (MRI) findings in determining the extent of disease in patients with morphea.

Morphea is an inflammatory disorder that produces sclerosis of the skin and subcutaneous tissues. Accurate assessment of disease depth, extent, and activity (inflammation) is critical for management but can be difficult to discern on clinical examination alone. This presents a challenge to care.¹ The objective of the present study was to compare clinical assessment of deep morphea with magnetic resonance imaging (MRI) findings. We hypothesized that MRI would be a useful clinical adjunct, demonstrating subclinical morphea activity and expansion.

Methods

This was a cross-sectional analysis of 20 consecutive patients from the Morphea in Adults and Children cohort with suspected deep morphea, defined as deeply sclerotic, poorly circumscribed plaques, indicating possible involvement of soft tissue (Figure). The University of Texas Southwestern Institutional Review Board approved this study, and written informed consent was obtained from all participants in the Morphea in Adults and Children cohort on inclusion.

Figure. Clinical and Magnetic Resonance Imaging (MRI) Findings in Patients With Suspected Deep Morphea.

A, A clinical photograph of subtle morphea of the left thigh (red box demonstrates location of scan). B, An axial fat saturated T2 weighted image, showing significant and subclinical subcutaneous involvement of this morphea lesion after MRI. This underscores the potential utility of MRI in evaluation of morphea because making the distinction of morphea activity vs damage is critical for management and can be challenging to assess in deep lesions. C, A clinical photograph of morphea involving the right lower extremity of another patient (red box demonstrates location of scan). D, An axial 3-dimensional subtracted postcontrast image indicating MRI findings of fascial involvement, which can be difficult to determine on clinical examination alone. The pink arrows indicate fascial enhancement; the yellow arrows indicate normal fascia of the contralateral extremity.

Patients were assigned a morphea subtype and given a clinical assessment score by a single dermatologist (H.T.J.) using the validated Localized Scleroderma Assessment Tool (including modified Localized Skin Severity Index [mLoSSI], Physician Global Assessment of Disease Activity [PGA-A], Localized Scleroderma Damage Index, and Physician Global Assessment of Disease Damage).^2,3 Pain and function were assessed using validated questionnaires and clinical examination. The clinical margins of the lesion were marked to be visible on imaging. Subsequently, patients underwent high-resolution MRI using a dedicated musculoskeletal protocol. Two musculoskeletal radiologists (P.P. and M.C.) blinded to the clinical assessment reviewed the images independently for lesion depth, extent, and activity (inflammation), resolving discrepancies by discussion with a senior musculoskeletal radiologist (A.C.).

Sample size calculations were not performed for this pilot study. Fisher exact tests, Wilcoxon-Mann-Whitney tests, and Cohen κ tests were used when appropriate. Two-tailed P values were used, and P values less than .05 were considered significant. All analyses were performed with SAS, version 9.4 (SAS Institute Inc).

Results

Of the 20 patients included in this analysis, 13 patients (65%) were white, 15 (75%) were women, and 14 (70%) had linear morphea. There were a total of 27 MRI examinations. At time of examination, 12 patients (44%) were receiving methotrexate therapy, 3 (11%) were receiving mycophenolate mofetil, 1 (4%) was receiving topical triamcinolone, and 11 (41%) underwent no therapy. Findings from MRI confirmed clinical suspicion of soft tissue involvement in 26 of 27 scans. A total of 7 scans showed involvement of muscle and/or deep fascia. Induration, a component of the Localized Scleroderma Assessment Tool score, was present more often in those patients with fascia/muscle involvement (6 of 7 MRI scans [86%], vs 5 of 20 [25%]; P = .005), and they had higher PGA-A scores (median [interquartile range], 37 [22-48] vs 0 [0-23]; P = .02).

Clinically active disease was suspected in 15 patients, while MRI results demonstrated active disease in 17 cases. In 5 patients, MRI findings showed disease activity where there was none apparent clinically. Patients with active disease seen on MRI results had higher clinical disease activity scores using the PGA-A (median [interquartile range], 25 [2-37] vs 0 [0-2]; P = .007) but not with the mLoSSI. Details of the comparison of clinical evaluation with MRI assessment are summarized in the Table. Results from the MRI showed that lesions extended beyond clinical margins by a mean of 6.3 cm. Cohen κ ranged from 0.780 to 1.000, indicating substantial to near-perfect agreement.

Table. Comparison of Clinical Assessment With Magnetic Resonance Imaging Findings.

Characteristic	Deep fascial/muscle involvement			Active disease
	Present	Absent	P Value	Present	Absent	P Value
Total, No.	7	20	NA	17	10	NA
Clinical variable, No. (%)
Pain	3 (43)	9 (45)	>.99	6 (35)	5 (50)	.40
Functional impairment	4 (57)	13 (65)	.66	10 (59)	7 (70)	.69
Induration	6 (86)	5 (25)	.005	11 (65)	0	.001
Clinically active disease (mLoSSI score >3), No. (%)	6 (86)	9 (45)	.04	12 (71)	3 (30)	.06
Clinical scores, median (IQR)
mLoSSI	6 (6-15)	0 (0-9)	.69	6 (0-7)	0 (0-4)	.96
LoSDI	11 (8-18)	10 (6-30)	.77	10 (6-17)	15 (7-25)	.39
PGA-A	37 (22-48)	0 (0-23)	.02	25 (2-37)	0 (0-2)	.007
PGA-D	38 (15-40)	35 (23-67)	.21	38 (20-45)	34 (25-54)	.60

Abbreviations: IQR, interquartile range; LoSDI, Localized Scleroderma Damage Index; mLoSSI, modified Localized Scleroderma Skin Severity Index; PGA-A, Physician Global Assessment of Disease Activity; PGA-D, Physician Global Assessment of Disease Damage.

Discussion

This cross-sectional analysis compared the clinical assessment of morphea with MRI evaluation. The findings corroborate those of previous retrospective studies, which showed that MRI results reveal clinically occult musculoskeletal involvement.^4,5,6 We also found that clinical examination alone underestimated lesion activity and extent. Specifically, the validated clinical parameters used to determine activity as part of the mLoSSI score did not correspond to features of activity on MRI findings, and in 5 patients (19%) MRI results demonstrated occult active disease. These discrepancies highlight potential misclassification of lesions as inactive when using the mLoSSI alone, particularly in deep morphea, in which activity is difficult to detect. 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. We also observed subclinical extension of lesions on MRI results, which indicates that pathology extends beyond clinical margins. The presence of activity on MRI results changed management with continuation or escalation of treatment and subsequent control of activity.

This analysis was limited by its small size and lack of reference standard. However, the results underscore the potential utility of MRI as an adjunct to clinical examination in morphea. Further studies are needed to define indications for MRI.