USE OF MAGNETIC RESONANCE IMAGING IN

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1 1602 RTHRITIS & RHEUMTISM Volume 37 Number 11, November 1994, pp , merican College of Rheumatology USE OF MGNETIC RESONNCE IMGING IN DIGNOSING EOSINOPHILIC FSCIITIS Report of Two Cases. L-SHIKH, C. FREEMN, L. VRUCH, and R. J. R. McKENDRY Objective. To determine the role of magnetic resonance imaging (MRI) in the diagnosis of eosinophilic fasciitis (EF), selection of appropriate biopsy site, and followup of treatment. Methods. MRI was used to examine 2 patients with EF at the time of their initial clinical presentation and after several months of treatment. T2-weighted axial, TZweighted axial with fat saturation, and T1- weighted axial post-gadolinium with fat saturation scans at 1.5T were obtained. Results. MRI demonstrated hyperintensity within the fascia. This defect resolved with treatment and clinical improvement. Conclusion. MRI is a useful noninvasive tool for diagnosing EF and for monitoring the effectiveness of therapy. Eosinophilic fasciitis (EF) is characterized by inflammation and thickening of the deep fascia, hypergammaglobulinemia, and peripheral and tissue eosinophilia. Eventually, these inflamed structures become collagenized, thickened, and sclerotic (1). Only by full-thickness skin-to-muscle biopsy can a definitive diagnosis of EF be made. The high contrast of magnetic resonance imaging (MRI) makes it an excellent technique for depicting. l-shaikh, MD: University of Ottawa, and Ottawa Civic and General Hospitals, Ottawa, Ontario, Canada; C. Freeman: Ottawa General Hospital; L. vruch, MD, FRCPC: University of Ottawa and Ottawa General Hospital; R. J. R. McKendry, MD, FRCPC: University of Ottawa and Ottawa General Hospital. ddress reprint requests to R. J. R. McKendry, MD, FRCPC, Ottawa General Hospital, Rheumatic Disease Unit, 501 Smyth Road, Room LM-10, Ottawa, Ontario, KlH 8L6, Canada. Submitted for publication November 8, 1993; accepted in revised form June 5, soft tissues (2). lthough there is a paucity of information about the use of MRI in fasciitis (2,3), we found it helpful in the diagnosis and treatment followup of the patients whose cases are presented here. CSE REPORTS Patient 1. This patient, 60-year-old man, presented in March 1993 with a 1-month history of rapidly progressive tightening of the skin of his upper back, lower legs, and arms. Raynaud s phenomenon was absent, and he had no history of dysphagia or arthralgia. He had no known exposure to polyvinylchloride or L-tryptophan. Examination showed sclerotic, thickened skin over the patient s upper back and the extensor surfaces of both lower legs and both forearms. There was no sclerodactyly. There was no joint tenderness or joint contractures. Laboratory examination showed eosinophilia of 2,600 X 106/liter (normal M O O X 106/liter), and normal findings on erythrocyte sedimentation rate (ESR), creatine kinase (CK), immunoglobulins, antinuclear antibodies (N), and rheumatoid factor (RF) studies. Pulmonary function tests revealed airway obstruction, which was attributed to chronic smoking complicated by bronchitis. arium swallow showed normal esophageal motility. n MRI (1.5T Magnetom SP 4000; Siemens, Erlangen, Germany) of the patient s lower legs (axial images) showed hyperintensity within the fascia and subcutaneous fat on fat-saturated T2-weighted images, with no evidence of myopathy (Figure 1). Postgadolinium (Magnevist, standard dose; erlex, erlin, Germany) fat-saturated TI-weighted images

2 MRI FOR DIGNOSING EF 1603 Figure 1. Magnetic resonance imaging axial scans through the mid-calves of patient 1 before () and after () treatment. T2-weighted (TR/TE = 2000/90) spin-echo images with fat saturation, showing hyperintense (inflamed) fascia (short arrows) and fascia plus subcutaneous fat (long arrows) only on the pretreatment images. showed fascial enhancement consistent with active inflammation (Figure 2). The anatomic region exhibiting the most abnormal fascia on MRI was selected as the site for skin and fascia biopsy, since we expected that the degree of image distortion from normal would roughly parallel the degree of pathologic change in the biopsy material. ccordingly, this MRI was used to identify a suitable site for a full-thickness biopsy of the patient s right calf. This biopsy showed marked thickening of the fascia accompanied by a mixed inflammatory cell infiltrate, consisting of lymphocytes and eosinophils, that extended deeply into the adjacent skeletal muscle and superficially into the subcutaneous fat. These features were consistent with a diagnosis of EF. Therapy was instituted with prednisone, 30 mg daily. fter 8 weeks, there was only partial response, and D-penicillamine was added at a dosage of 125 mg daily. fter 6 months of combined treatment, there was a further reduction in skin tightness and induration. n MRI performed at this time showed a marked reduction of fascial hyperintensity, consistent with reduced fascial inflammation (Figures 1 and 2). Currently, the patient remains on a regimen of tapering doses of prednisone 15 mg daily and D-penicillamine 250 mg daily.

3 1604 L-SHIKH ET L Figure 2. Magnetic resonance imaging axial scans through the mid-calves of patient 1 before () and after () treatment. T1-weighted (715/15) gadolinium-enhanced spin-echo images with fat saturation, showing enhanced (inflamed) fascia (arrows) only on the pretreatment images. The muscle appeared normal in all scans. Patient 2. This patient, a 37-year-old woman, presented in October 1990 with complaints of muscle pain and progressive muscle weakness that was followed by progressive swelling of her lower legs and hands associated with paresthesias of her hands. Findings of muscle biopsy (performed at a community hospital) were consistent with myositis; there was no description of the adjacent skin or fascia. The patient refused corticosteroid therapy. In December 1991, she was admitted to the Rheumatic Disease Unit at Ottawa General Hospital, with progressive swelling and tightness of the skin of her lower legs and fingers. She described worsening muscle pain and weakness. She had mild dysphagia and had lost 20 pounds in 2 months. Raynaud s phenomenon was absent. Examination showed extensive, nonpitting edema and induration of the skin and subcutaneous

4 MRI FOR DIGNOSING EF 1605 Figure 3. Photographs of the hands of patient 2, before () and after () treatment. tissues of her hands and lower legs, with moderate limitation of finger flexion and extension (Figure 3). She had mild proximal muscle weakness, but no joint tenderness or swelling, Gottron s papules, or heliotrope rash. Laboratory examination revealed an eosinophilia of 920 X 1O6hiter (normal X 106/liter); the ESR was 24 mmhour (Wintrobe). Evaluation of muscle enzyme levels showed elevated aldolase at 13 unitshiter (normal 1-8) and lactate dehydrogenase at 286 unitshiter (normal ) and a normal CK value. IgG was elevated at 25.2 gditer (normal ) and IgM was elevated at 2.9 gmlliter (normal ). RF and N were negative. Radiographs of the hands showed moderate periarticular osteopenia, but no erosions or extraosseous calcifications. Electromyography revealed myopathic changes consisting of short-duration lowamplitude polyphasic potentials. Results of chest radi- ography, lung function studies, and an esophagogram were normal. MRI of the lower limbs showed scattered areas of curvilinear hyperintensity adjacent to both the superficial fascia and intermuscular fascia of the thighs and legs (Figure 4). No abnormality could be detected in the muscles of her thighs or lower legs. The MRI was used to identify a region of fascia with increased signal intensity in the patient s right thigh, and a full-thickness skin-to-muscle biopsy was performed. The biopsy showed thickening of the fascia accompanied by mild-to-moderate infiltration with mononuclear cells and a few eosinophils, consistent with a diagnosis of EF. The adjacent skeletal muscle showed chronic nonspecific myositis with a focal perivascular inflammatory infiltrate, without necrotic or regenerating muscle fibers. Treatment was started with prednisone, 60 mgl day, and physical therapy, and there was moderate

5 1606 L-SHIKH ET L Figure 4. Magnetic resonance imaging scans through the proximal thighs of patient 2, before () and after () treatment. T2-calculated images show actual T2 values for these tissues. These are derived from T2-weighted double-echo conventional spin-echo images (2000/22/90), using standard Siemens software. On the pretreatment T2-weighted image, inflamed fascia shows increased signal intensity (arrows). improvement. However, a daily dose of at least 30 mg of prednisone was required for control of the symptoms and signs. fter 6 months of prednisone therapy, methotrexate was added as a steroid-sparing agent. During 14 months of methotrexate therapy (12.5 mg/ week), the prednisone dosage was reduced to 20 mg

6 MRI FOR DIGNOSING EF 1607 Figure 5. Magnetic resonance imaging axial scans through the mid-calf of a normal volunteer., The out-of-phase FLSH image (15*/350/22; according to the technique described in ref. 2) shows an artifactual fascial plane (short arrows) because water and fat are out of phase or opposed. chemical shift artifact (long arrow) is also present., On the in-phase FLSH image (15-/350/20), the fascial plane artifact disappears, but the chemical shift artifact persists. daily, and there was continuing reduction in the level of pain, improved muscle strength, near resolution of the peripheral skin induration, and restored flexibility (Figure 3). followup MRI was obtained 20 months after the initial scan, and showed complete resolution of the area of fascial hyperintensity (Figure 4). DISCUSSION EF is a scleroderma-like disorder, characterized by thickening of the skin of the limbs, often in association with peripheral eosinophilia, hypergammaglobulinemia, and elevated ESR (3). EF is differentiated from similar conditions on the basis of differences in the clinical and histopathologic features. For example, compared with systemic sclerosis (SSc) and limited scleroderma (LS), the epidermis and dermis are usually normal in the early stages of EF. The inflammation is most pronounced in the fascia and lower subcutis in EF, whereas in SSc the inflammatory cell infiltrate is often more pronounced in the dermis or dermosubcutaneous junction (2,4). In contrast to SSc, Raynaud s phenomenon and visceral organ involvement are uncommon in EF. Unlike LS or SSc, EF often responds to corticosteroid treatment. In this report, we have presented 2 cases of EF in which MRI was used as a tool to aid in the diagnosis, to determine an appropriate biopsy site, and to monitor the results of treatment. MRI has been shown to differentiate among soft tissue structures (2). Normal ligaments, tendons, and cortical bone are of very low intensity, whereas muscle and hyaline articular cartilage are of intermediate intensity. Optimal MRI technique is required to demonstrate early or mild fasciitis. The fascia, a thin fibrous structure, is normally dark on all MRI sequences. Fascia1 inflammation will cause thickening and/or hyperintensity on TZweighted sequences and/or enhancement with gadolinium. problem arises because the fascia is located at a boundary between muscle and fat, and this boundary is subject to 2 MRI artifacts that can obscure or simulate subtle disease. First, the chemical shift artifact produces thickened dark and bright lines at this boundary, simulating disease. y using a calculated T2 image (as in patient 2), this artifact is mitigated. Second, a phase artifact can occur with gradient echo (e.g., FLSH) images (Figures 5 and ), if inappropriate imaging parameters are used. Two reports describing MRI in a total of 3

7 1608 L-SHIKH ET L patients with EF (2,5) suggested its usefulness as an aid in diagnosis. In those patients, MRI revealed fascial thickening and increased signal intensity on TZweighted images. In both reports, MRI helped to direct the location for biopsy, which in turn, confirmed the diagnosis of EF. In our study as well as in these 2 reports, it is assumed that there is some correlation between the degree of increased signal intensity of the fascia on MRI and the level of fascial inflammation on histologic examination of the biopsy samples. Our 2 cases, which closely resemble those in the 2 reports, lend further support to the use of MRI as a diagnostic tool for EF. oth previous reports (2,5) suggested that MRI findings were indicative of the stage of disease. However, neither group of investigators supported this opinion with descriptions of sequential MRIs. De Clerck et al (2) reported marked thickening and splitting of the fascia into 2 parallel lines on MRI of a patient with longstanding disease, and increased signal intensity in the superficial muscle fibers adjacent to the fascia in a patient with early disease. Those authors ascribed the thin dark lines in their images (Figure 5) to fascial planes. We believe these may be boundaryphase artifacts caused by the muscle water and subcutaneous fat being out of phase or opposed at a 22-ms echo time. t a 20-ms echo time, the water and fat are in phase, and the fascial planes disappear (Figure 4). We propose that a fat-saturated spin-echo technique (TZweighted andor T1-weighted with gadolinium) (as in our patient 1) be used for MRI of fascia, since it eliminates both artifacts. MRI of plantar fasciitis has been shown to be of some diagnostic value, although this is not the case with nodular fasciitis (6,7). retrospective review of 3 patients with nodular fasciitis reported no unique tomographic or MRI findings, and suggested that the lack of consistent imaging characteristics might be explained by the variation in the histopathology of the lesions (7). Conversely, a study of 8 patients with plantar fasciitis showed significantly thickened fascia (T1 images) and focal areas of increased signal intensity compared with age- and sex-matched control subjects (6). Neither of these focal forms of fasciitis is known to be associated with EF. Followup MRIs performed on our patients showed that tissue signal intensity, including that of the fascia, reverted to normal during the time when there was moderate (patient 1) and marked (patient 2) clinical improvement. Thus, we found MRI to be useful as a means of monitoring therapy. To our knowledge these are the only reported cases with followup MRIs showing a correlation with clinical improvement. These 2 cases illustrate that MRI is a useful, noninvasive tool for the diagnosis, biopsy site selection, and evaluation of treatment in patients with EF. Until MRI of fascia is prospectively evaluated in patients with similar conditions (such as LS, SSc, or eosinophilic myalgia), it remains to be determined if the MRI changes reported in EF are unique or highly specific for this condition. REFERENCES 1. arnes L, Rodnan GP, Medsger T, Short D: Eosinophilic fasciitis: a pathological study of twenty cases. m J Pathol %: , De Clerck LS, Degryse HR, Wouters E, van Offel JF, De Schepper M, Martin JJ, Stevens WJ: Magnetic resonance imaging in the evaluation of patients with eosinophilic fasciitis. J Rheumatol 16: 127G1273, Lakhanpal S, Ginsburg WW, Michet CJ, Doyle J, Moore S: Eosinophilic fasciitis: clinical spectrum and therapeutic response in 52 cases. Semin rthritis Rheum 17: , Doyle J, Connolly SM, Winkelmann RK: Cutaneous and subcutaneous inflammatory sclerosis syndromes. rch Dermatol 118:88&890, Le Tallec Y, rlet P, Montane de la Roque P, Schlaifer D, Dary M, Oilier S, Mazieres, Laroche M, Cantagrel, Jacquemier JM: Magnetic resonance imaging in eosinophilic faciitis (letter). J Rheumatol M , erkowitz JF, Kier R, Rudicel S: Plantar fasciitis: magnetic resonance imaging. Radiology 179: , Meyer C, Kransdorf MJ, Jelinek JS, Moser RP: Magnetic resonance and computed tomographic appearance of nodular fasciitis. J Comput ssist Tomogr 15: , 1991