Contrast enhanced power Doppler sonography:: Comparison of different administration forms of the ultrasound contrast agent Levovist®

Purpose: Objective of the present study was the comparison of various administration forms of the ultrasound contrast medium Levovist(R) with regard to duration and intensity of contrast enhancement in patients with tumors of the liver or pancreas. Patients and Methods: Seven patients with tumors of the liver or pancreas were examined prospectively using power Doppler sonography. Ultrasound contrast enhancement was achieved using Levovist(R) (8 ml, 400 mg/ml) in three different administration forms: 1(st) as a bolus injection through the main channel, 2(nd) through the injection valve of an intravenous cannula, or 3(rd) as a continuous infusion. Semiquantitative evaluation of the degree of contrast enhancement over the course of the examination was conducted by three independent examiners. Results: Levovist(R), administered by continuous infusion, resulted in a significantly longer average period of contrast enhancement (9:43 min (extratumoral), 7:34 min (intratumoral)) than did the same dosage administered as a bolus injection through the main channel (6:01 min (extratumoral), 4:54 min (intratumoral), p = 0.0156 (extratumoral); p = 0.0313 (intratumoral), but contrast intensity was decreased. Bolus injection through the injection valve of the i.v. cannula was associated with decreased duration and intensity of contrast enhancement compared with injection through the main channel. Conclusion: Compared with bolus injection, the continuous infusion of Levovist(R) resulted in a significant prolongation of the duration but in a decreased intensity of contrast enhancement. Administration of Levovist(R) through the injection valve does not result in optimal contrast enhancement and is therefore not recommended.