Author: Xiaohu Li, Jianjun Shen, Guozhi Zhang, Sihua Zhong, Jingjie Zhou 👨🔬
Affiliation: United Imaging Healthcare 🌍
Purpose:
Visualization of carotid artery vessel wall on computed tomography angiography (CTA) imaging is challenging. This study aims to develop a novel post-processing technique, black-blood computed tomography (BBCT), for improved assessment of the carotid artery wall on CT.
Methods:
We retrospectively collected 42 patients who underwent craniocervical non-contrast CT followed by CTA. The BBCT technique, developed in two stages: Firstly, a deep learning-based image registration is employed to align the non-contrast CT and CTA scans; Afterwards, a dedicated subtraction algorithm is applied to the two-registered images to generate BBCT images that differentiate the carotid artery wall from the lumen. The resulting BBCT and conventional CTA images were compared with signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), followed by a quantitative evaluation of consistency in measuring plaque burden and carotid artery wall thickness (CAWT) by two readers. Receiver-operating characteristic analysis assessed CAWT's predictive ability for hypertension and diabetes (cardiovascular risk factors), using clinical diagnosis as the reference standard.
Results:
Compared to conventional CTA, BBCT images showed superior visualization of carotid artery wall, with significantly higher SNR (12.75±14.22 vs.9.86±14.34) and CNR (61.69±48.20 vs. 58.80±31.55) (both p<0.05). Accordingly, the inter-observer agreement for plaque burden (ICC=0.860 vs.0.667) and CAWT (ICC = 0.885 vs.0.652) measurement was notably greater on BBCT than conventional CTA. Of the 49 patients (30 males; mean age 70.30±11.79 years), 71.43% were hypertensive and 45.24% were diabetic. The BBCT-derived CAWT were significantly higher in hypertensive (1.23±0.19 mm) and diabetic (1.21±0.20 mm) groups compared to non-hypertensive (0.99±0.22 mm) and non-diabetic (0.94±0.24 mm) groups (both p<0.05). CAWT demonstrated good predictive value for both hypertension and diabetes, with AUC of 0.673 and 0.756, respectively.
Conclusion:
BBCT provides better depiction of the carotid artery wall, facilitating more reliable measurement of CAWT that may serve as a valuable predictor of cardiovascular-related diseases such as hypertension and diabetes.