Experimental correlation between T2* and ultimate compressive strength in lumbar porcine vertebrae.

ABSTRACT

RATIONALE AND OBJECTIVES: The authors used magnetic resonance (MR) imaging to investigate the correlation between T2* measurements of trabecular bone and the ultimate compressive strength of lumbar porcine vertebrae. METHODS: Five pigs that weighted 25-32 kg were sacrificed and imaged with a 1.5-T MR system. T2* of the lumbar vertebrae was measured from gradient-echo images. The vertebrae were individually compressed at a fixed speed in the direction of the spine until crushed. The maximum load a vertebra could resist was recorded. RESULTS: T2* ranged from 7.1 to 14.5 msec. T2* determined from 5-mm coronal sections differed from that determined from axial and sagittal sections (P < .05). Between 2.9 and 5.4 kN of force (296-550 kg) was needed to crush a vertebra. A linear correlation between the ultimate compressive strength and T2* of all vertebrae was observed for all imaging planes and section thicknesses (P < .001, except for 10-mm sagittal images, for which P < .002). The T2* determined for the axial plane showed the best correlation with the ultimate compressive strength (r = -0.83). CONCLUSION: The correlation between T2* values and vertebral strength indicates that MR imaging may potentially be used to predict fracture risks in patients.