Vertebral Marrow Fat Content and Diffusion and Perfusion Indexes in Women with Varying Bone Density: MR Evaluation

Abstract

The subjects experienced a decrease in vertebral marrow maximum enhancement and enhancement slope and an increase in marrow fat content as bone density decreased. The reduction in perfusion indexes occurred only within the vertebral body and not in the paravertebral tissues supplied by the same artery.

Vertebral blood perfusion reduction associated with vertebral bone mineral density reduction: A dynamic contrast‐enhanced MRI study in a rat orchiectomy model

“…Signal enhancement over time was recorded. Maximum enhancement, defined as the maximum percentage increase in signal intensity from baseline, was derived from the first-pass phase of signal intensity enhancement according to the following equation as described by Griffith et al (7,8):…”

Degenerative endplate changes of the lumbosacral spine: Dynamic contrast‐enhanced MRI profiles related to age, sex, and spinal level

“…DCE MRI studies have shown delayed peak enhancement in transient osteoporosis of the hip and increased enhancement rate in rheumatoid arthritis and may support the observation of delayed and increased maximum enhancement in degenerative changes in the presence of local edema or inflammation (25,26). Other studies have shown decreasing enhancement slope with increasing fatty marrow percentage and may explain decreased WIN in degenerative changes in presence of fatty marrow (27).…”

“…Other investigators have reported type 1 TICs for normal marrow (9,10,12,13). However, a DCE MRI study of females with varying mineral bone density reported only pattern 2 TICs of normal marrow, perhaps because degenerative endplate changes were not avoided at ROI placement or because most females were postmenopausal, with reduced bone mineral density and, possibly, increased marrow fat (27,30,39). Thus, evidence of pattern 2 in normal marrow may be related to more pronounced red to yellow marrow conversion.…”

Interpreting a DXA Scan in Clinical Practice

“…Because DXA scanners use two X-ray energies in the presence of three types of tissue (bone mineral, lean tissue and adipose tissue), there are considerable errors arising from the inhomogeneous distribution of adipose tissue in the human body (Tothill and Avenell 1994) (which can be studied either through cadaver studies (Svendsen, Hassager et al 1995), CT imaging to delineate the distribution of adipose tissue external to bone (Kuiper, van Kuijk et al 1996;Lee, Wren et al 2007) or MRI to measure the percentage of marrow fat inside bone (Griffith, Yeung et al 2006)). These studies suggest BMD measurement errors of around 5 to 8%.…”