Comparison of retrospectively ECG-gated and nongated MDCT of the chest in an emergency setting regarding workflow, image quality, and diagnostic certainty

Abstract

Purpose: This study aims to assess the influence of ECG-gated acquisition on workflow and to compare image quality and diagnostic certainty for retrospectively ECG-gated and nongated multidetector computed tomography of the chest in the emergency suite. Materials and methods: Thirty-two consecutive patients were referred for both an ECG-gated and a nongated CT to rule out traumatic thoracic injury (n=15) or acute aortic dissection (n=17). The time from the start of the transportation from the emergency suite to the CT room until the start of the CT scan was recorded. Using a scoring system, the image quality of axial images and multiplanar reformats, the presence of disease, and the subjective diagnostic certainty were assessed with regard to the vascular structures, the bone structures, and the lung parenchyma. Results: The time needed for transportation and patient preparation was 12.1±1.7 min (8.1-14.5 min). The motion artifacts of the thoracic aorta and the supra-aortic vessels were significantly reduced in the ECG-gated data acquisition compared with the nongated technique (P<0.001). Subjective diagnostic certainty for assessment of the aorta was significantly better using ECG gating. The image quality of the lung parenchyma (P<0.005), the spine (P<0.005), and the ribs (P<0.002) was inferior in the ECG-gated data sets but did not compromise the detection rate of traumatic lesions and fractures. Conclusion: Performing ECG gating in the emergency room did not slow down the diagnostic workup. ECG-gated acquisition performed better in the assessment of the aorta, but image quality for lung and bone structures was slightly reduced. Further studies are required to assess the influence of the imaging technique on the diagnostic outcome.

Low dose dual-source CT angiography of the thoracic aorta

“…Furthermore, when ECG-gating is used, scan times are not significantly prolonged, resulting in minimal impact on CT workflow [15]. Until recently, retrospective ECG-gating was the method of choice, allowing accurate calculation of time intervals between the R-R waves in the cardiac cycle after all the CT data is acquired and the flexibility of choosing different arbitrary reconstruction phases for image interpretation within the R-R window of the cardiac cycle.…”

“…CT angiographic techniques using electrocardiography (ECG) gating have been employed to minimize motion artifact due to cardiac pulsation [9][10][11][12][13][14][15]. Furthermore, when ECG-gating is used, scan times are not significantly prolonged, resulting in minimal impact on CT workflow [15].…”

Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography: a pilot study to establish normative values for transcatheter therapies

“…ECG assistance for aortic studies allows the synchronisation of data acquisition to the heart cycle in order to obtain CT data during the diastolic phase when heart movement is minimal thus reducing motion artefact [17][18][19].…”

Use of multidetector computed tomography to guide management of pneumothorax

“…It is still controversial whether to use ECG gating in chest trauma CT scanning. Although ECG gating may eliminate motion artifacts and improve image quality, it may however lose valuable time in emergency situations and increase the radiation dose significantly [26,27]. Special care has been taken in pediatric patients.…”