[3-phase spiral CT--a new noninvasive procedure for the differentiation of multifocal liver lesions]

Dynamic CT is an established method for the differentiation of focal liver lesions by monitoring the contrast enhancement. It is especially restricted in the assessment of small and multiple lesions due to respiratory organ movements. Spiral-CT allows the examination of large volumes in the breathhold technique. Spiral-CT with controlled i.v. contrast media administration can be used for the assessment of the entire liver in distinct phases of perfusion. We describe the use of this new technique in a patient with multifocal nodular hyperplasia (FNH), for whom assessment with dynamic CT was not suitable. The lesions were first located with a conventional contrast-enhanced CT-scan. The impossibility to assess all the lesions with dynamic CT led to the decision to perform a three-phase spiral-CT with three sequential scans (native, arterial, and portal perfusion phase). The entire liver was scanned after power injector-controlled i.v. administration of contrast media with the following parameters: 1) arterial phase: 70 ml contrast media, 2 ml/s, start delay 18 s; 2) portal phase: 80 ml contrast media, 2 ml/s, start delay 60 s; slice 8 mm, table feed 8 mm, increment 4 mm; 24 s of breathhold data acquisition.