Arterial double-contrast dual-energy MDCT: in-vivo rabbit atherosclerosis with iodinated nanoparticles and gadolinium agents

Abstract

An in-vivo feasibility study of potentially improved atherosclerosis CT imaging is presented. By administration of two different contrast agents to rabbits with induced atherosclerotic plaques we aim at identifying both soft plaque and vessel lumen simultaneously. Initial injection of iodinated nanoparticle (INP) contrast agent (N1177 -Nanoscan Imaging), two to four hours before scan, leads to its later accumulation in macrophage-rich soft plaque, while a second gadolinium contrast agent (Magnevist) injected immediately prior to the scan blends with the aortic blood. The distinction between the two agents in a single scan is achieved with a double-layer dual-energy MDCT (Philips Healthcare) following material separation analysis using the reconstructed images of the different x-ray spectra. A single contrast agent injection scan, where only INP was injected two hours prior to the scan, was compared to a double-contrast scan taken four hours after INP injection and immediately after gadolinium injection. On the single contrast agent scan we observed along the aorta walls, localized iodine accumulation which can point on INP uptake by atherosclerotic plaque. In the double-contrast scan the gadolinium contributes a clearer depiction of the vessel lumen in addition to the lasting INP presence. The material separation shows a good correlation to the pathologies inferred from the conventional CT images of the two different scans while performing only a single scan prevents miss-registration problems and reduces radiation dose. These results suggest that a double-contrast dual-energy CT may be used for advanced clinical diagnostic applications.

Image quality of conventional images of dual‐layer SPECTRAL CT: A phantom study

“…A number of studies have been conducted on the dual‐layer technology, primarily looking at applications of dual‐energy analysis . However, only few studies have yet been published on image quality of conventional images acquired on the IQon .…”

“…A number of studies have been conducted on the duallayer technology, primarily looking at applications of dualenergy analysis. 5,[9][10][11][12][13][14][15] However, only few studies have yet been published on image quality of conventional images acquired on the IQon. 16 In general, the conventional images acquired on the IQon are very similar to images acquired on the iCT, as can be seen in Fig.…”

“…Dual-layer detector CT scanners, such as the IQon Spectral CT (Philips Healthcare, Best, the Netherlands), always acquire two datasets, independent of protocol. 5 In the IQon Spectral CT, a single X-ray source is used to expose a detector, consisting of two scintillator layers. The top layer is more sensitive to the low-energy photons, whereas the bottom detector layer absorbs more of the high-energy photons.…”

“…Dual‐layer detector CT scanners, such as the IQon Spectral CT (Philips Healthcare, Best, the Netherlands), always acquire two datasets, independent of protocol . In the IQon Spectral CT, a single X‐ray source is used to expose a detector, consisting of two scintillator layers.…”

Dual-energy CT and CT perfusion for improved CT stroke imaging

“…Dual-layer detector CT (DLCT) scanners, such as the IQon Spectral CT (Philips Healthcare, Best, the Netherlands), always acquire two datasets, independent of protocol [53]. In the DLCT, a single X-ray source is used to expose a detector, consisting of two scintillator layers.…”