Chest CT in patients with shortness of breath: Comparing high pitch CT and conventional CT on respiratory artefacts and dose.

INTRODUCTION

To investigate chest respiratory artefact reduction using High Pitch Dual Source Computed Tomography (HPCT) compared to conventional CT (CCT) in symptomatic patients with shortness of breath.

METHODS

Forty patients were prospectively examined on a second-generation Dual Source scanner. They were randomly divided into two groups: twenty patients underwent an experimental HPCT protocol and twenty control cases CCT protocol. Respiratory artefacts were evaluated using an ordinal score (0, 1 and 2) assigned by two readers with five and thirty years of experience. A qualitative assessment was performed using two categorical groups, group 1 = acceptable and group 2 = unacceptable. Dose Length Product (DLP) was compared.

RESULTS

The two groups showed a statistical difference in artefacts reduction (p < 0.0001). HPCT demonstrated no artefacts in 82% of cases, while CCT showed no artefacts in 39% of cases. DLP showed no statistical differences (p = 0.6) with mean = 266.9 for HPCT and mean = 282.65 for CCT. HPCT provides high table speed in the z-direction allowing a high temporal resolution, which reduces respiratory artefacts during free-breathing acquisition. Despite the use of two x-ray tubes, the HPCT did not increase the dose to the patient but provided the highest images quality.

CONCLUSIONS

In the emergency setting, HPCTs have been critical for achieving good image quality in uncooperative patients.

IMPLICATIONS FOR PRACTICE: Acute respiratory failure is a common emergency department presentation, and the choice of high-speed acquisition CT may increase image quality.