RESUMO
The authors evaluated the usefulness of an ultrasound contrast agent (SHU 508A) to help identify different scintigraphic phases of revascularization of the femoral head in children with Legg-Calvé-Perthes (LCP) disease. Eighteen unenhanced and contrast-enhanced power Doppler images and scintigrams of the pathologic hip in 18 children with LCP disease were compared. The scintigraphic stages of Conway's classification for LCP disease (stage A, recanalization; stage B, neovascularization) were compared with the degree of vascularity and mean peak enhancement ratios obtained from analysis of Doppler sonograms. Qualitatively, the patient's age (< or = or >7 years old) at the time of examination had a significant effect on the degree of vascularity visualized on postcontrast ultrasound images according to the scintigraphic stages. Quantitatively, there were no differences for overall mean peak enhancement ratios between stages A and B. Power Doppler ultrasound increased visualization of Doppler signals significantly but did not help in differentiating scintigraphic phases.
Assuntos
Cabeça do Fêmur/irrigação sanguínea , Doença de Legg-Calve-Perthes/diagnóstico por imagem , Neovascularização Fisiológica/fisiologia , Intensificação de Imagem Radiográfica/métodos , Ultrassonografia Doppler em Cores/métodos , Criança , Pré-Escolar , Meios de Contraste , Feminino , Humanos , Masculino , Probabilidade , Cintilografia/métodos , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Estatísticas não Paramétricas , TecnécioRESUMO
A total of 26 children (26 affected, 25 control hips) with Legg-Calvé-Perthes' disease (LCP) met the cooperation requirements for inclusion in the study using contrast-enhanced power Doppler sonography for assessment of changes in the revascularization flow. Sagittal sonograms were obtained before and at the peak effect of an intravenously injected microbubble-based contrast agent. Overall mean peak enhancement ratios were greater for children with later onset of disease (>5.8 years old) than for those with earlier onset (< or = 5.8) (p = 0.02). The use of ultrasound (US) contrast agents improved depiction of proximal femoral vascularity in all regions of the femoral head: epiphysis (n = 3, pre; n = 8, postcontrast), physis (n = 12, pre; n = 21, postcontrast) and metaphysis (n = 6, pre; n = 8, postcontrast) and resulted in a marked increase in the number of mean pixel intensity values within the physis (p = 0.02). In conclusion, contrast-enhanced power Doppler sonography is an effective method for demonstration of changes from the revascularization process in LCP, particularly within the physis.