Dermatomyositis: Patterns of MRI findings in muscles, fascia and skin of pelvis and thigh. Issue 141 (August 2021)

• Record Type: Journal Article
• Authors: Spalkit, Stanzin; Sinha, Anindita; Prakash, Mahesh; Sandhu, Manavjit Singh
• Is Part Of: European journal of radiology. Issue 141(2021)
• Publication Date: 2021-08
• Subjects: Dermatomyositis -- MRI -- Thigh -- Myopathy -- Proximal -- Skin; Medical radiology -- Periodicals; Radiology -- Periodicals; Radiologie médicale -- Périodiques; Medical radiology; Periodicals; 616.075705
• DOI: 10.1016/j.ejrad.2021.109812
• Languages: English
• ISSNs: 0720-048X

Abstract

Highlights: MRI findings in dermatomyositis (DM) range from subtle myofascial involvement to florid muscle, skin, and subcutaneous tissue changes. The purpose of this review is to provide an overview of the MR imaging features of the lower limbs in patients with dermatomyositis and the role of contrast enhanced imaging, diffusion weighted imaging and whole-body MRI. The reader should be able to identify the different patterns of muscle, myofascial, skin, and subcutaneous tissue involvement. Abstract: Purpose: This review discusses characteristic, subtle, and florid changes in muscle, fascia, skin, and subcutaneous tissue of the lower limbs in MR imaging in patients with dermatomyositis. Material and methods: This review is based on the analysis of 43 patients with dermatomyositis who were imaged from January 2014 to March 2021 in our institute as well a critical review of literature of MRI in dermatomyositis. Results: Muscle involvement is predominantly bilaterally symmetric and involves anterior, posterior as well as medial compartments of the thigh. Diffuse intramuscular hyperintensity on T2-weighted images is a common pattern of involvement. Isolated myofascial involvement or muscular with myofascial involvement can also occur. Nodular areas of hyper intensity and enhancement is another uncommon pattern of muscle involvement. Reticular pattern of subcutaneous tissue involvement and skin thickening is best seen on fat saturated T2 -weighted images. Calcification in the subcutaneous tissues appears hypointense with a surrounding hyperintense rim on all pulse sequences which shows peripheral enhancement. MRI patterns of involvement range from subtle myofascial and skin involvement to florid muscular involvement. Diffusion weighted imaging is useful for myofascial involvement. Whole body MR can detect changes at unusual sites in muscles and extra skeletal involvement. Contrast enhanced imaging has no added benefit. Treatment responders show a return to normal signal intensity on MRI. Conclusion: This review highlights the patterns of muscle, skin, and subcutaneous tissue involvement of thighs in dermatomyositis on conventional MRI and the role of whole-body MR, diffusion weighted imaging and limited role of contrast enhanced imaging.