TRANSJUGULAR INTRAHEPATIC PORTOSYSTEMIC SHUNTS - IMPROVED EVALUATION WITH ECHO-ENHANCED COLOR DOPPLER SONOGRAPHY, POWER DOPPLER SONOGRAPHY,AND SPECTRAL DUPLEX SONOGRAPHY

OBJECTIVE. We assessed the feasibility of contrast-enhanced color Dopp ler, power Doppler, and spectral duplex sonography for visualization a nd quantification of flow through transjugular intrahepatic portosyste mic shunts (TIPS) in patients in whom the baseline sonographic evaluat ion was unsatisfactory. SUBJECTS AND METHODS. Thirty-three patients un derwent color Doppler, power Doppler, and spectral duplex sonography a fter TIPS insertion or before TIPS revision (mean time interval +/- SD , 1 +/- 1 day). All sonograms were obtained before and after patients received echo-enhancing contrast material. Sonography was evaluated wi th regard to presence or absence of flow in the mid portion, portal se gment, and hepatic segment of the shunt. The maximal peak velocity was measured in the mid portion of the shunt. For identifying and quantif ying stenoses, the percentage of luminal diameter reduction was calcul ated at the tightest part of the shunt. Shunt angiography and measurem ents of portosystemic pressure gradients were independently evaluated and compared with the sonographic findings. RESULTS. Flow visualizatio n on unenhanced color Doppler sonography was significantly improved th rough the use of power Doppler sonography and contrast-enhanced color Doppler and power Doppler sonography (p < .01). Between contrast-enhan ced power Doppler and contrast-enhanced color Doppler sonography, a si gnificant difference was found in the portal and hepatic segments (p < .05). All shunt stenoses (n = 8) and occlusions (n = 3) were revealed by power Doppler sonography, whereas color Doppler sonography failed to reveal six of eight stenoses. Compared with unenhanced sonography, the quality of spectral duplex sonography was improved in eight patien ts after contrast enhancement (p < .05). Maximal peak velocity ranged from 54 to 252 cm/sec (mean +/- SD, 132.7 +/- 52.1 cm/sec) in normal s hunts and from 24.5 to 70.0 cm/sec (mean +/- SD, 45.0 +/- 18.9 cm/sec) in stenosed shunts. No correlation was found between maximal peak vel ocity and portosystemic pressure gradients (r = .28). CONCLUSION. Unen hanced power Doppler and contrast-enhanced color and power Doppler son ography can be helpful in the assessment of TIPS status in patients wh o previously underwent unsatisfactory sonography. These techniques may allow anatomic evaluation and quantification of shunt stenosis in mos t patients. Contrast enhancement may also considerably improve the qua lity of spectral duplex sonography.