In vivo quantification of delayed gadolinium enhancement in the nucleus pulposus of human intervertebral disc

Abstract

Purpose:To quantify the delayed contrast agent enhancement in the nucleus pulposus of the intervertebral disc by means by T1 relaxation time measurements, and to correlate the enhancement with visual grading of disc degeneration. Diffusion of nutrients through the endplate is a key factor in tissue viability in the intervertebral disc. It can be simulated in vivo using magnetic resonance imaging (MRI) by measuring delayed gadolinium (Gd) enhancement of the disc. Materials and Methods:Twenty male volunteers underwent a lumbar spine examination at 1.5T. T2-weighted sagittal images were used to score disc degeneration. T1 relaxation times were measured before and 90 minutes after intravenous administration of Gd-DTPA-BMA by applying a series of sagittal single-slice inversion-recovery fast spin-echo (IR-FSE) scans. Results:A total of 93 discs were analyzed. A statistically significant decrease in the T1 relaxation time of the nucleus pulposus was observed as a result of contrast-agent intake. The percentage change in the T1 relaxation rate for individual discs was up to 126%. A positive trend was observed between the change in the T1 relaxation rate and the grading of disc degeneration. Conclusion:Quantification of delayed enhancement of the intervertebral disc may provide a new means of studying alterations in degenerative disc disease (DDD) that explain the variation in diffusion into the intervertebral disc.

Advances in Magnetic Resonance Imaging for the Assessment of Degenerative Disc Disease of the Lumbar Spine

“…Previous study by Antoniou et al has established a direct correlation between diffusion rate and glycoaminoglycan content in the NP [24]. In recent study by Niinimaki et al, delayed gadolinium(Gd)-enhanced magnetic resonance imaging contrast (dGEMRIC) has been applied to study the diffusion characteristic of the IVD in vivo [25]. Gd is a T 1 shortening agent.…”

“…In the study by Niinimaki et al, a T 1 map was collected before and after intravenous injection of 0.2 mM/kg Gd-based contrast agent. The percentage decrease in T 1 after Gd injection correlates with grading of disc degeneration [25]. However, recent research has linked the usage of Gd-based MR contrast agent with a rare but severe medical condition know as nephrogenic systemic fibrosis (NSF) [26].…”

Association of lumbar artery narrowing, degenerative changes in disc and endplate and apparent diffusion in disc on postcontrast enhancement of lumbar intervertebral disc

“…Degenerative changes of the disc, such as disc space narrowing and signal intensity changes of nucleus pulposus, have been shown to associate with altered contrast enhancement in MR measurements [2,4,5]. This association may be explained by changes in the nutritional pathway consisting of vertebral arteries, vertebral vascular network, endplate cartilage, and diffusional properties of the nucleus pulposus.…”

“…Since the intervertebral disc is primarily non-vascular tissue, small nutrients, such as oxygen and glucose, are transported to the cells of the nucleus pulposus entirely by diffusion from the blood vessels reaching the vertebral endplate and the outer margin of annulus fibrosus [1]. Magnetic resonance (MR) imaging can be used to evaluate the transport of small solutes from systemic blood circulation to intervertebral discs by quantifying the enhancement of the disc after intravenously injected contrast media [2,3].…”

Assessment of glycosaminoglycan concentration in vivo by chemical exchange-dependent saturation transfer (gagCEST)

“…The negative charge density of cartilage tissue (and hence GAG concentration) can therefore be inferred through monitoring the differences of the T 1 values with and without the agent (5,6). This method fails in IVDs and heart valves because of the slow diffusion of Gd(DTPA) 2Ϫ into the tissue (7). T 1 MRI can map the GAG concentration in both diarthrodial joints and IVDs (4,8).…”