Soft tissue density variations in thalassemia major: a possible pitfall in lumbar bone mineral density measurements by dual-energy X-ray absorptiometry.

Osteoporosis is common in patients with thalassemia major. A 16-year-old patient with thalassemia major was referred for evaluation of osteoporosis. The results of dual-energy X-ray absorptiometry in a patient with thalassemia major are presented. The patient underwent measurements of the spine in both AP and lateral position. The DXA scan of the spine in AP projection showed diffusely increased density overlying the lower thoracic and upper lumbar vertebrae. The overall density of L(2)-L(4) was 0.6465 g/cm(2) (4.93 SD as compared with young adults). The DXA scan of the spine in lateral projection showed diffusely increased density in front part of the spine. The BMD of the L(3) vertebra was 0.3669 g/cm(2) (0.30 SD as compared with young adults). It is important to interpret the images visually in order to obtain true values of BMD, and preclude invalid BMD measurements.