In vivo tomographic assessment of the heart and blood vessels with intravascular ultrasound

Abstract

Intravascular ultrasound (IVUS) has emerged from being a research tool to becoming an intrinsic part of modern invasive cardiology mainly due to imaging micro anatomy in vivo. For the first time, it is possible to base therapeutic decisions not only on lumenograms but also on vessel wall assessment. IVUS has both diagnostic and intervention associated potential. The diagnostic strength of IVUS is its ability to describe compensatory coronary artery enlargement as a response to arteriosclerosis, to assess intermediate lesions, and to reveal occult left main stem disease and angiographically "silent" arteriosclerosis. The intervention associated potential of IVUS is the optimal device selection, i.e., rotablators in calcified lesions or atherectomy devices in large plaque burden. The effects of PTCA on vessel wall morphology can be studied in great detail and the effect on luminal gain can be assessed. Several groups have shown that the residual plaque area ("plaque burden") even after angiographically successful PTCA still lies in the range of 60%. A significant reduction in this number may influence long-term outcome after PTCA. Minimal luminal area and residual plaque area after PTCA seem to be indicators of restenosis, while the presence or absence of dissections seems to be less predictive. The main mechanism of restenosis after PTCA is vessel shrinkage, not intimal hyperplasia. Intravascular monitoring of stent expansion led to high-pressure stent deployment with a significant increase in post-procedural luminal diameters and the ability to withhold anticoagulation in patients with optimal stent deployment. In pulmonary and aortic diseases, IVUS contributed significantly to the understanding of aortic dissection and pulmonary hypertension. Additionally, with intracardiac ultrasound left and right ventricular function can be assessed. Intracardiac ultrasound has gained clinical usefulness for guiding transcatheter ablation in patients with conduction system abnormalities. In the future, integrated devices, such as balloons on IVUS catheters, steerable catheters, integrated flow and pressure transducers, tissue characterization, and 0.018" IVUS guide wire will further enhance the usefulness of IVUS.

Investigating the impact of spatial priors on the performance of model-based IVUS elastography

“…Model-based elastography could provide the computational framework for visualizing circumferential stress and thus detecting plaques. Intravascular ultrasound (IVUS) provides real-time, two-dimensional cross-sectional images of the arterial wall (Gorge et al 1998, Ge et al 1999, Hoffmann et al 1999, Larsen et al 2002 that accurately depict plaque morphology (Vink and Pasterkamp 2002). However, IVUS cannot quantify the mechanical properties of vascular tissues (de Korte et al 2000, de Korte et al 2002, Maurice et al 2008).…”

Intensive Use of Intravascular Ultrasound during Coronary Angioplasty. A Six-month Campaign

“…Consequently, in recent years IVUS has become a standard method for diagnosis in many PTCA centres (10,15). The MUSIC study (8) has encouraged this development as it demonstrated that IVUS guided stent implantation, according to strict dilatation criteria, led not only to a low rate of acute stent thrombosis but also a low rate of restenosis and target vessel revascularization.…”

Experimental Studies With a 9F Forward-Looking Intracardiac Imaging and Ablation Catheter

“…[3][4][5][6] It has transformed the field of cardiac electrophysiology (EP) from a diagnostic tool to a potent treatment method. Catheter ablation is now performed for virtually every type of arrhythmia, including Wolff-Parkinson-White syndrome, 3,4 concealed accessory pathways, 3,4 atrioventricular nodal reentrant tachycardia, 7 atrial flutter, 8 atrial fibrillation, 9 incisional atrial reentrant tachycardia, 10 and ventricular tachycardia. 7 Catheter ablation is also performed in all chambers of the heart and in patients with diverse structural cardiac abnormalities.…”