Ultra-fast whole-heart CT using z-motion of the X-ray source
X-ray computed tomography (CT) has become a prominent tool for cardiac imaging since the introduction of multislice CT in 1998. This prominence has come progressively with the increase in the number of detector rows and in the scanner rotation speed. However, the accuracy of cardiac CT imaging is currently strongly dependent on the patient (patients with heartbeat arrythmia, who are more at risk, are more difficult to image), and this accuracy furthermore comes at the cost of a high dose. The long-term goal of this research is to enable highly accurate CT imaging of the whole heart independently of the patient condition and with a dose comparable to typical CT scans. We hypothesize this goal will be reached using a new scanning concept, called complete single-beat whole-heart (CSWH) scanning, where tomographically-complete data covering the full heart is obtained within one heartbeat.
For this first research on cardiac imaging with CSWH scans, we will focus on the following aims:
- development and implementation of reconstruction algorithms for accurate imaging from cone-beam data on relevant CSWH scans
- comparative evaluation of CSWH scans in terms of data requirement and dose imparted using various collimation strategies
- comparative evaluation of CSWH scans in terms of imaging performance using computer simulated data and real data of anthropomorphic phantoms and using human ROC observer studies
Efficient snap-shot CT imaging of the entire heart using staggered circular scans
We are interested in x-ray computed tomography (CT) imaging of the coronary arteries, commonly referred to as coronary CT angiography (CTA). Specifically, we suggest an innovative, low-cost solution to the problem of performing accurate coronary CTA within a single heartbeat. This solution is the result of combining the latest advances in image reconstruction theory with careful system design considerations. More specifically, we propose to mitigate artifacts occurring with circular CB tomography of the entire heart, using:
- a new concept of scans, called staggered circular scans, that use several x-ray sources together to obtain CB data on parallel circular trajectories for the net effect of reducing the cone angle without requiring axial motion
- innovative reconstruction algorithms that draw on recent advances in image reconstruction theory.
Staggered circular scans are defined with an index K that gives the number of x-ray sources involved. We will focus our effort on the following aims:
- Development, implementation and validation of a preferred reconstruction algorithm for accurate coronary CTA using staggered circular scans of index K = 2, K = 3 and K = 4.
- Comparative evaluation of staggered circular scans against each other and against the conventional circular data acquisition.
- Demonstration of robustness for real data.
- Feasibility demonstration of accurate general body imaging with a scanner designed to perform staggered circular scans.