The triple rule out CT in acute chest pain: a challenge for emergency radiologists?

Abstract

Purpose: To evaluate the feasibility of triple rule out computed tomography (TRO-CT) in an emergency radiology workflow by comparing the diagnostic performance of cardiovascular and general radiologists in the interpretation of emergency TRO-CT studies in patients with acute and atypical chest pain.

Methods: Between July 2017 and December 2019, 350 adult patients underwent TRO-CT studies for the assessment of atypical chest pain. Three radiologists with different fields and years of expertise (a cardioradiologist-CR, an emergency senior radiologist-SER, and an emergency junior radiologist-JER) retrospectively and independently reviewed all TRO-CT studies, by trans-axial and multiplanar reconstruction only. Concordance rates were then calculated using as reference blinded results from a different senior cardioradiologist, who previously evaluated studies using all available analysis software.

Results: Concordance rate was 100% for acute aortic syndrome (AAS) and pulmonary embolism (PE). About coronary stenosis (CS) for non-obstructive (<50%), CS concordance rates were 97.98%, 90.91%, and 97.18%, respectively, for CR, SER, and JER; for obstructive CS (>50%), concordance rates were respectively 88%, 85.7%, and 71.43%. Moreover, it was globally observed a better performance in the evaluation of last half of examinations compared with the first one.

Conclusions: Our study confirm the feasibility of the TRO-CT even in an Emergency Radiology department that cannot rely on a 24/7 availability of a dedicated skilled cardiovascular radiologist. The "undedicated" radiologists could exclude with good diagnostic accuracy the presence of obstructive stenosis, those with a clinical impact on patient management, without needing time-consuming software and/or reconstructions.

Keywords: CTA; Chest pain; Coronary CT angiography; Triple rule out.

Fig. 1

An example of axial TRO-CT images (a–h) used for coronary arteries post-processing

Fig. 2

MPR-MIP reformatted images for right (a, d) and left (a, b, c) coronary artery evaluation. On the right portion of each image, the orientation along the three major anatomic planes (axial, coronal, and sagittal) is clearly showed (red lines)

Fig. 3

Volume rendering (a–c) and curved-MPR (d–i) images, normally used for coronary artery evaluation on dedicated workstations

Fig. 4

Concordance rate of diagnosis of PE, AAS, and total CAD between a senior cardioradiologist (as “gold standard”), who previously evaluated studies using all available analysis software, and another cardioradiologist, a senior emergency radiologist, and a junior emergency radiologist who evaluated studies only by MPR analysis. CAD is considered as non-obstructive CAD (rule out) and obstructive CAD (rule in)

Fig. 5

Axial (a–d) and MPR-MIP (e, f) CT images from a patient with obstructive CAD on left anterior coronary artery (arrows). As in Fig. 2, on the right portion of e–f images, the orientation along the three major anatomic planes (axial, coronal, and sagittal) is also showed (red lines)

Fig. 6

The same case of Fig. 5, previously post-processed using all available dedicated software: volume rendering (a), curved-MPR (b, c), vessel analysis with straight and cross-section views (d), MPR thick (e), and perfusion defect analysis (f, g). The obstruction of left anterior descending coronary artery is showed by arrows (a–d) or asterisks (cross-sectional images in d), while subendocardial perfusion defects along the anterior wall are evidenced by arrowheads (e–g)