Role of radiologic imaging in genetic and acquired neuromuscular disorders

Abstract

Great technologic and clinical progress have been made in the last two decades in identifying genetic defects of several neuromuscular diseases, as Spinal Muscular Atrophy, genetic muscular dystrophies and other genetic myopathies. The diagnosis is usually challenging, due to great variability in genetic abnormalities and clinical phenotypes and the poor specificity of complementary analyses, i.e., serum creatine kinase (CK) and electrophysiology. Muscle biopsy represents the gold standard for the diagnosis of genetic neuromuscular diseases, but clinical imaging of muscle tissue is an important diagnostic tool to identify and quantifyies muscle damage. Radiologic imaging is, indeed, increasingly used as a diagnostic tool to describe patterns and the extent of muscle involvement, thanks to modern techniques that enable to definethe definition of degrees of muscle atrophy and changes in connective tissue. They usually grade the severity of the disease process with greater accuracy than clinical scores. Clinical imaging is more than complementary to perform muscle biopsy, especially as ultrasound scans are often mandatory to identify the muscle to be biopsied. We will here detail and provideWe will herein provide detailed examples of the radiologic methods that can be used in genetic and acquired neuromuscular disorders, stressing pros and cons.

Eliminating Nox2 reactive oxygen species production protects dystrophic skeletal muscle from pathological calcium influx assessed in vivo by manganese‐enhanced magnetic resonance imaging

“…Computed tomography and ultrasound possess several limitations that hinder their use owing to concerns with radiation, depth of imaging and inter‐ and intra‐operator reliability (Ortolan et al . ). Magnetic resonance imaging (MRI) is a useful tool for imaging dystrophic muscle; however, early in disease progression the MRI scans may appear normal given that the technique relies upon the appearance of morphological alterations such as increased inflammation, fibrosis or fatty infiltrates (Ortolan et al .…”

“…Magnetic resonance imaging (MRI) is a useful tool for imaging dystrophic muscle; however, early in disease progression the MRI scans may appear normal given that the technique relies upon the appearance of morphological alterations such as increased inflammation, fibrosis or fatty infiltrates (Ortolan et al . ). In addition, the morphological alterations can be influenced by ethnicity and adaptations due to exercise (Ortolan et al .…”

“…In addition, the morphological alterations can be influenced by ethnicity and adaptations due to exercise (Ortolan et al . ). Therefore, the ability to image molecular alterations in disease pathology, such as calcium influx, may provide a more sensitive measure for tracking disease progression throughout the life of the patient.…”

Advanced MRI Patterns of Muscle Disease in Inherited and Acquired Myopathies: What the Radiologist Should Know

“…2 Tissue biopsy is considered the gold standard for the diagnosis of genetic myopathies. 3 However, classification of the underlying disease is frequently only possible with the contribution of clinical, genetic, histopathologic, and imaging assessment.…”

“…In recent years, advances in muscle imaging have shown promise as a useful supportive tool for the evaluation of myopathies, through identification of specific patterns of muscle involvement, detection of subclinical features, and description of disease extent and severity. 3 LGMD, limb-girdle muscular dystrophy; LL, lower leg; GlM, gluteus maximus; Gmed, gluteus medialis; Gmin, gluteus minimus; MD, myotonic dystrophy; PV, paravertebral; RF, rectus femoris; RYR1, ryanodine receptor 1 related myopathy; SM, semimembranosus; SCM, sternocleidomastoid; ST, semitendinosus; TA, tibialis anterior; TP, tibialis posterior.…”