[Artefact reducing in diagnosis of lung embolism using spiral CT with saline bolus]

To improve the diagnostic efficacy of bolus-enhanced spiral CT (SCT) in the detection of pulmonary embolism using a saline push immediately after bolus injection of the contrast medium.

The study included 90 patients with suspected acute or chronic pulmonary embolism. The CT scan was performed in a caudocephaled direction. In Group I (n = 60) we applied a bolus contrast injection (120 ml, 3 ml/s, 300 mg J/ml), after a median delay of 25 s. Group II (n = 30) had the same contrast injection which was immediately followed by an additional saline push (60 ml, 2 ml/s). Streak artifacts originating from high contrast concentrations in the superior vena cava were rated on a 4-point scale for different locations: right pulmonary artery, pars basalis, truncus anterior, and the segmental upper lobe arteries.

The incidence of artifacts in group I was nearly twice as high as in group II. The difference was significant (p < 0.05) for the upper and anterior superior lobe artery, the right pulmonary artery and the pars basalis.

The presented protocol significantly reduces artifacts mainly by a washout of contrast medium in the superior vena cava.