Dynamic contrast enhanced-magnetic resonance imaging study of the nutrition pathway for lumbar intervertebral disk cartilage of normal goats

Abstract

Objective: Study of the nutrition pathway for lumbar intervertebral disk cartilage of normal goats.

Methods: Four lumbar intervertebral disks from each of eight 24-month-old goats (32 disks) were studied. After the goats had been anesthetized, signal intensity changes in the regions of interest (ROI) were observed by dynamic contrast enhanced magnetic resonance scanning. Before and after enhancement at the time points of 0, 5, 10, and 30 mins, and 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 hs, the ROI signal intensity was measured, and the time-signal intensity curve and peak times analyzed.

Results: Signal intensity in the vertebral bodies reached a peak at 0 min and decreased quickly thereafter. Signal intensity in the cartilage endplate zones reached the first peak at 30 mins and then went down slightly before increasing to a second peak at 2 hs. Signal intensity in the nuclei pulposus was negative within 5 mins, increased slowly to a peak at 2 hs, and declined thereafter.

Conclusion: Nutrient metabolism of the lumbar intervertebral disks of normal goats occurs mainly through the cartilage end-plate pathway.

Figure 1

Region of interest were selected corresponding to five regions, namely the upper and lower vertebral bodies, upper and lower cartilage endplate zones, and nuclei pulposus.

Figure 2

Observation of the morphology of normal goat vertebral disks (A) T2‐TSE‐SPAIR sequence: the nuclei pulposus show high intensity, and the peripheral fibrous rings and cartilage endplates low intensity. (B) T1‐TSE‐SPIR sequence: the vertebral disks show isointensity, and the nuclei pulpous and fibroid annuli are difficult to e distinguish from each other. (C) T1‐TSE‐SPIR sequence after the injection of Gd‐BOPTA: the nuclei pulposus are not enhanced, whereas the vertebral bodies are significantly enhanced. The transverse lumbar arteries can be seen entering the vertebrae.

Figure 3

Enhanced T1‐SPIR sequences showing the dynamic MR changes at different time points (A) pre‐injection of Gd‐BOPTA; (B) at 0 mins; (C) at 5 mins; (D) at 10 mins; (E) at 30 mins; (F) at 1.0 h; (G) at 1.5 hs; (H) at 2.0 hs; (I) at 2.5 hs; and (J) at 3 hs.

Figure 4

The time‐signal intensity of five ROIs. EPZ, end plate zone; NP, nucleus pulposus; VB, vertebral body.