Figure 3.

Negative correlation of bone marrow edema in histopathological assessment and magnetic resonance imaging. (a) Magnetic resonance imaging of zygapophyseal joints (cyan arrows) without detectable bone marrow edema (asterisk, vertebral body; open square, epidural space; plus signs, superior and inferior articular processes of the zygapophyseal joint; hash sign, processus spinosus). (b) Hematoxylin and eosin staining of the zygapophyseal joint, revealing numerous mononuclear cells in the bone marrow (yellow arrow) and a relatively small amount of edema (20%) in the bone marrow (red arrow). (c) Immunohistochemical analysis of CD3⁺ T cells (red arrow), showing dense infiltrates of CD3⁺ T cells (yellow arrow).