Contrast-enhanced power Doppler imaging: Comparison with scintigraphic phases of revascularization of the femoral head in Legg-Calve-Perthes disease

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-Calve-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 (less than or equal to 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.