Longitudinal features of stir bright signal in FSHD¹

Abstract

Moderate/severe STIR hyperintensities often foreshadow fatty replacement over a 2-year interval. Whether longer time courses are required to observe muscle degeneration and fatty replacement in some subjects remains to be explored.

Whole‐body magnetic resonance imaging evaluation of facioscapulohumeral muscular dystrophy

“…Previous studies have indicated that there is an active phase of inflammatory muscle disease characterized by edema‐like changes on fluid‐sensitive MRI sequences (e.g., STIR), and that this phase is followed by rapid fat replacement . Indirect evidence for the phenomenon comes from the distribution of fat infiltration scores in this and other studies .…”

“…The available data on muscle imaging in FSHD suggests that subclinical disease is detectable using localized MRI . T1‐weighted imaging has been used to identify the degree of muscle replacement by fat, and hyperintensity on fluid‐sensitive MRI sequences has been shown to represent an active inflammatory phase that precedes fat infiltration . The ability to detect these subclinical changes is a major advancement toward clinical trial preparedness in FSHD.…”

Magnetic Resonance Imaging and Spectroscopy Assessment of Lower Extremity Skeletal Muscles in Boys with Duchenne Muscular Dystrophy: A Multicenter Cross Sectional Study

“…For example, the 9–10.9 year age group was decreased compared to the 5–6.9 years in the soleus and the 11–14 year age group was decreased compared to the 5–6.9 year age group in the VL. The decrease in 1 H 2 O T 2 at the older ages relative to the younger ages may be due to less inflammation (in part, or whole, due to the increased incidence of steroid use in older boys [37]) and increased fibrosis [38], [39], [40]. Importantly, this study also demonstrates that 1 H 2 O T 2 is increased in those DMD subjects that have minimal lipid infiltration in skeletal muscle (less than 5%), suggesting T 2 may be a valuable marker of muscle damage and inflammation/edema in young subjects of 5–6.9 years, prior to fatty tissue infiltration.…”

Skeletal muscle quantitative nuclear magnetic resonance imaging and spectroscopy as an outcome measure for clinical trials (part II)

“…Для разных мышц сущест-вует достоверная корреляция между средним значением сигнала Т2 и средней скоростью жировой инфильтра-ции. У пациентов с лице-плече-лопаточной мышечной дистрофией было показано, что в мышцах с гиперин-тенсивностью на Т2-ВИ в дальнейшем отображаются существенные жировые дегенеративные изменения [47,48]. Такие наблюдения являются основными в су-ждении о пользе применения Т2-сигнала воды в мыш-цах в качестве биомаркера активности процесса при нервно-мышечных болезнях.…”