Objective: To investigate the use of magnetic resonance imaging in the detection of metastatic tumors involving the discovertebral junction of the spine in cadaveric specimens and patients, with histologic findings as the reference standard.
Methods: Magnetic resonance imaging studies were performed on 30 DVJs in 10 cadavers with documented metastatic bone disease. Anatomic sectioning and histologic evaluations were performed, and anatomic slices were correlated with the magnetic resonance images. For clinical study, magnetic resonance imaging examinations in three patients with vertebral metastasis were reviewed.
Results: On magnetic resonance imaging, the signal intensity characteristics of vertebral body metastases were variable. Magnetic resonance imaging failed to detect metastatic foci invading the cartilaginous endplates. On microscopic examination, infiltration of the discovertebral junction by tumorous tissue was found in 11 (69%) of the 16 discovertebral junctions that had an irregular contour, and in 5 (31%) disrupted discovertebral junctions. In three specimens and three patients, microscopic examination revealed tumor metastasis to the intervertebral disc. In no specimen magnetic resonance imaging afforded depiction of discal invasion by tumor.
Conclusions: Our results lend further support to the theory that metastatic tumors can invade the cartilaginous endplate through defects in its substance, allowing direct contact of tumor and disc. Minimal tumor invasion of the discovertebral junction may not be identified at magnetic resonance imaging or gross anatomic inspection, or both, because small metastatic foci may be obscured by abnormalities in the morphology of the cartilaginous endplate.