Griffith JF et al. (2005) Vertebral bone mineral density, marrow perfusion, and fat content in healthy men and men with osteoporosis: dynamic contrast-enhanced MR imaging and MR spectroscopy Radiology 236: 945–951

Previous studies have shown age-related changes in perfusion and fat content of vertebral marrow and have suggested that reduced perfusion might shift the balance between osteoblastic and osteoclastic activity, thereby altering bone density. Using dual X-ray absorptiometry (DXA), MRI and spectroscopy, researchers in Hong Kong investigated a possible relationship between bone-marrow fat content, perfusion and bone mineral density (BMD).

This prospective study initially enrolled 90 men, and 82 were included in the final analyses (mean age 73 years, range 67–101 years). DXA data enabled assignment of patients to one of three groups—normal BMD (n = 42), OSTEOPENIA (n = 23), or OSTEOPOROSIS (n = 17). Imaging of the lumbar spine was performed, and mean values for vertebral marrow fat content and perfusion determined for each patient group.

Average vertebral marrow fat content was significantly higher in patients with osteoporosis (P = 0.002) or osteopenia (P = 0.034) than in men with normal BMD. In contrast, vertebral marrow perfusion was significantly reduced in osteopenic (P = 0.023) and osteoporotic (P < 0.001) men.

Despite limitations of a small sample size and an all-male patient population, Griffith et al. conclude that a reduction in BMD is accompanied by decreasing vertebral marrow perfusion and increasing marrow fat content. The authors suggest further studies to determine whether these are related or independent variables.