RESUMO
A new method for estimating in vivo bone mineral density (BMD) and characterizing the shape of cancellous bone has been proposed using the results of ultrasonic inspection for the diagnosis of osteoporosis. The method is based on two-dimensional bone area fraction S (percent bone area between bone and bone marrow) calculated from the difference in the speed of ultrasonic wave propagation through cancellous bone. It was shown that the two-dimensional area fraction of a heel bone gives a good relationship to the BMD by DXA (dual energy x-ray absorptiometry) testing of human heel bone (calcaneus) and spine (vertebrae lumbar), as expressed by the relation, BMD (g/cm2) = 0.0167S for heel bone (r = 0.83), and BMD (g/cm2) = 0.0254S + 0.123 for the spine (r = 0.77). Shape characterization is based on the image simulation procedure employing eight random variables from a computer and the statistical results of fractal analysis for numerous cancellous bone patterns. We also demonstrate the validity of the shape characterization using autopsy specimens as a diagnostic tool for osteoporosis.
Assuntos
Densidade Óssea , Osso e Ossos/diagnóstico por imagem , Osteoporose/diagnóstico , Ultrassonografia/métodos , Absorciometria de Fóton , Adulto , Idoso , Algoritmos , Simulação por Computador , Feminino , Calcanhar/diagnóstico por imagem , Calcanhar/patologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Pessoa de Meia-Idade , Fatores de TempoAssuntos
Contratura/etiologia , Dedos/fisiopatologia , Doenças Musculares/complicações , Sarcoidose/complicações , Contratura/fisiopatologia , Feminino , Humanos , Pessoa de Meia-Idade , Doenças Musculares/patologia , Doenças Musculares/cirurgia , Sarcoidose/patologia , Sarcoidose/cirurgia , Resultado do TratamentoRESUMO
Dorsal defect of the patella is an approximately 1-cm, circular, radiolucent, well-marginated benign lesion invariably located in the superlateral aspect of the patella. Only approximately 50 cases have been described in the world literature, of which < 10 cases have been studied histologically. We report two patients with bilateral, virtually symmetrical, dorsal defects of the patella and describe the arthroscopic and histologic findings. Case 1 was a 14-year-old girl and case 2 was a 35-year-old man. Cartilage perforations were seen via arthroscopy on the cartilage surface of both knees. The pathophysiology of this disorder remains to be clarified, although van Holsbeeck et al. proposed that vastus lateralis traction injury in the ossification process of the patella may be involved, as in the case of bipartite patella. The present arthroscopic and histological findings support this hypothesis.
