A digital radiology method for assessing vertebral osteoporosis

The radiologic identification of vertebral fractures is usually subjective and reproducibility is poor. This paper describes a new digital radiologic method to perform vertebral morphometry, i.e. osteoradiometry (ORM). Lateral radiographs of the thoracic and lumbar spine were obtained in 50 premenopausal women and digitalized by means of a video camera. A special computer software enables to calculate the anterior (Ha), middle (Hm), and posterior (Hp) heights of vertebral bodies (T4-L5) and the morphometric indices of vertebral fractures. ORM reproducibility was assessed by comparing repeated measurements made by two radiologists: the intra- and interobserver variation coefficients (CV) were respectively 1.5% and 2.3% for Hp; 1.3% and 2% for Hm; 1.4% and 2.1% for Ha. The normal range for vertebral dimensions was therefore established. The anterior and posterior heights increased from T4 to L2, but for L3-L5 the posterior height was lower than the anterior height (Ha/Hp > 1). Vertebral heights positively correlated with the standing heights of the subjects (r = 0.2, p < 0.05). Weight and the body mass index (BMI) were not correlated with vertebral heights. These normal values, compared with those found in osteoporosis patients, will allow to assess ORM diagnostic efficacy in identifying vertebral fractures.