Coronary artery assessment in Kawasaki disease with dual-source CT angiography to uncover vascular pathology

Abstract

Background: Kawasaki disease (KD) is a vasculitis with formation of coronary artery aneurysms (CAAs) that can lead to myocardial ischemia. Echocardiography is the primary imaging modality for the coronary arteries despite limited visualization. Coronary angiography (CAG) is the gold standard yet invasive with high-radiation exposure. To date however, state-of-the-art CT scanners enable high-quality low-dose coronary computed tomographic angiography (cCTA) imaging. The aim of our study in KD is to report (i) the diagnostic yield of cCTA compared to echocardiography, and (ii) the radiation dose.

Methods and results: We collected data of KD patients who underwent cCTA. cCTA findings were compared with echocardiography results. In 70 KD patients (median age 15.1 years [0.5-59.5 years]; 78% male; 38% giant CAA), the cCTA identified 61 CAAs, of which 34 (56%, with a Z score > 3, in 22 patients) were not detected by echocardiography. In addition, the left circumflex (aneurysmatic in 6 patients) was always visible upon cCTA and not detected upon echocardiography. Calcifications, plaques, and/or thrombi were visualized by cCTA in 25 coronary arteries (15 patients). Calcifications were seen as early as 2.7 years after onset of disease. In 5 patients, the cCTA findings resulted in an immediate change of treatment. The median effective dose (ED) in millisievert differed significantly (p < 0.01) between third-generation dual-source and other CT scanners (1.5 [0.3-9.4] (n = 56) vs 3.8 [1.7-20.0] (n = 14)).

Conclusions: The diagnostic yield of third-generation dual-source cCTA combined with reduced radiation exposure makes cCTA a favorable diagnostic modality to complete the diagnosis and long-term treatment indications for KD.

Key points: • cCTA is a favorable diagnostic modality to complete the diagnosis and long-term treatment indications for Kawasaki disease. • Kawasaki disease patients with proven coronary artery involvement on echocardiography require additional imaging.

Keywords: Computed tomography angiography; Coronary artery disease; Echocardiography; Kawasaki disease; Pediatrics.

Fig. 1

Flow diagram of patient inclusion

Fig. 2

Remodeling of the LAD (in a single patient) performed with the third-generation dual-source CT scanner. a Significant aneurysms in the LAD (5.3-mm diameter, Z score 16.28). b Remodeling of the LAD in the dynamic phase (2.8-mm diameter, Z score 4.23)

Fig. 3

Dynamic and static phase. The years counted being the years after onset of disease. In the first 2 years, the CAAs show most of the remodeling (regression), whereas the years thereafter show secondary complications as calcification, plaque, and stenosis

Fig. 4

a CAAs missed by echocardiography while detected by cCTA. Y = number of CAAs. b CAAs missed by echocardiography while detected by cCTA. Y = number of CAAs

Fig. 5

Proximal and distal aneurysm in the RCA with calcification depicted by cCTA vs echocardiography

Fig. 6

Effective dose (in mSv) with tube voltage (kV) used in the same acquisition in order to depict the coronary arteries. Third-generation dual-source CT scanner vs other CT scanners. For the other CT scanners, there were no tube voltages (kVp) of 70 kV, 80 kV, or 90 kV in these acquisitions