Diffusion-weighted MRI of denervated muscle: a clinical and experimental study

Abstract

This DWMRI study demonstrates that enlargement of extracellular fluid space in muscle denervation is an early phenomenon occurring several days before the appearance of EMG and histological abnormalities.

Spinal cord metabolism and muscle water diffusion in whiplash

“…7 However, the fast ADC for chronic whiplash (3.2 Â 10 À3 mm 2 s À1 ) was faster than established data, 7 suggesting a passive enlargement of the extra-myocellular space secondary to denervation atrophy. 5 The observed biochemical alterations and muscle water diffusion provide preliminary evidence to suggest involvement of the spinal cord with subsequent denervation atrophy 5 in a small sample of patients with chronic whiplash.…”

“…Altered cord biochemistry has been observed in neurological disorders 3 and cervical myelopathy 4 using MRS, and increased water diffusion of denervated muscles is detailed with DWI. 5 We compared cord biochemistry and neck muscle water diffusion in subjects with chronic whiplash and controls.…”

The Pearls and Pitfalls of Magnetic Resonance Imaging for the Spine

“…15 The use of DWI in the spine also extends beyond quantifying the physiologic response in the intervertebral discs to treatments, as in evidence of its use in differentiating the following: (1) osteoporotic and metastatic vertebral body fractures, 11,12,27,76 (2) degeneration versus infectious abnormalities of the vertebral end plate, 34 (3) identification of nerve root compression, 2,3,17,103 and (4) diffusional properties of water in the spinal musculature of healthy participants and those with spinal pain. 36,41,58,104 Accordingly, DWI represents an innovative imaging application to quantify the precise movement of water within a variety of soft tissues that can be used to measure the physiological effects of disease and/or trauma. As such, it is fast becoming a potentially valuable clinical tool to study cellular level responses to conservative management strategies commonly delivered by physicians and physical therapists (eg, injections, manual therapy, exercise, and physical agents).…”

Advancements in Imaging Technology: Do They (or Will They) Equate to Advancements in Our Knowledge of Recovery in Whiplash?

“…Diffusion-weighted MRI can be applied to skeletal muscle, 31,134 where it has been used to detect both temporary exercise-induced changes in regional blood flow 81,135 and early signs of denervation 56 (FIGURE 5). For example, significant increases in muscle ADC can be observed during and following brief submaximal isometric contractions, 133 following peripheral nerve injury and associated denervation, 48 and in individuals with subacute lumbosacral radiculopathy.…”