Fractal analysis of lumbar vertebral cancellous bone architecture.

Osteoporosis is characterized by bone mineral density (BMD) decreasing and spongy bone rearrangement with consequent loss of elasticity and increased bone fragility. Quantitative computed tomography (QCT) quantifies bone mineral content but does not describe spongy architecture. Analysis of trabecular pattern may provide additional information to evaluate osteoporosis. The aim of this study was to determine whether the fractal analysis of the microradiography of lumbar vertebrae provides a reliable assessment of bone texture, which correlates with the BMD. The lumbar segment of the spine was removed from 22 cadavers with no history of back pain and examined with standard x-ray, traditional tomography, and quantitative computed tomography to measure BMD. The fractal dimension, which quantifies the image fractal complexity, was calculated on microradiographs of axial sections of the fourth lumbar vertebra to determine its characteristic spongy network. The relationship between the values of the BMD and those of the fractal dimension was evaluated by linear regression and a statistically significant correlation (R = 0.96) was found. These findings suggest that the application of fractal analysis to radiological analyses can provide valuable information on the trabecular pattern of vertebrae. Thus, fractal dimensions of trabecular bone structure should be considered as a supplement to BMD evaluation in the assessment of osteoporosis.

[Lung fibrosis quantified by HRCT in scleroderma patients with different disease forms and ANA specificities] / La TC polmonare ad alta risoluzione nelle diverse forme cliniche e specificità anticorpali della sclerodermia.

OBJECTIVE: To define the prevalence of interstitial lung fibrosis in systemic sclerosis (SSc) and its relationship with the different clinical forms of disease and ANA specificities. METHODS: Fifty patients with SSc were submitted to pulmonary high resolution computed tomography (HRCT). Lung abnormalities were evaluated according to Warrick's score that considers both the severity and the extent of fibrotic lesions. RESULTS: Pulmonary HRCT abnormalities were observed in 84% of SSc patients. Ground glass aspects (60%), irregular pleural margins (56%) and septal/subpleural lines (68%) were the most common lesions. The distribution of these abnormalities favoured the posterior basilar segments of both lungs. HRCT findings were significantly more frequent in males and in patients with the cutaneous diffuse form of SSc and with the specific antibody anti-Scl70. CONCLUSIONS: HRCT is a very useful method for the diagnosis of interstitial lung fibrosis in SSc. Warrick's score permits to quantify the HRCT findings and to evaluate their relationship with the disease clinical forms and ANA specificities.