3-D guidance of complex pulmonary artery stent placement using reconstructed rotational angiography with live overlay.

Technologies which allow rotational angiographic image acquisition and three dimensional (3-D) vascular reconstruction with subsequent fluoroscopic registration for live 3-D image overlay are rapidly being adopted. We present the first use of rotational angiography with integrated 3-D image overlay for guidance during complex pulmonary artery stent placement. Technical considerations, advantages, and limitations of this procedural strategy are discussed.

Potential role of three-dimensional rotational angiography and C-arm CT for valvular repair and implantation.

Imaging modalities utilized in the interventional cardiology suite have seen an impressive evolution and expansion recently, particularly with regard to the recent interest in three-dimensional (3D) imaging. Despite this, the backbone of visualization in the catheterization laboratory remains two-dimensional (2D) X-ray fluoroscopy and cine-angiography. New imaging techniques under development, referred to as three-dimensional rotational angiography (RA) and C-arm CT, hold great promise for improving current device implantation and understanding of cardiovascular anatomy.

Clinical feasibility of a fully automated 3D reconstruction of rotational coronary X-ray angiograms.

Background: Although fixed view x-ray angiography remains the primary technique for anatomic imaging of coronary artery disease, the known shortcomings of 2D projection imaging may limit accurate 3D vessel and lesion definition and characterization. A recently developed method to create 3D images of the coronary arteries uses x-ray projection images acquired during a 180 degrees C-arm rotation and continuous contrast injection followed by ECG-gated iterative reconstruction. This method shows promise for providing high-quality 3D reconstructions of the coronary arteries with no user interaction but requires clinical evaluation.

Three-dimensional coronary visualization, Part 2: 3D reconstruction.

Fully automatic generation of a volumetric representation of the coronary artery tree can be achieved by rotational coronary angiography acquisition and three-dimensional tomographic reconstruction. The generated volume datasets can assist the physician during percutaneous coronary interventions by visualizing three-dimensional coronary morphology and offering utility tools to derive various quantitative measurements. These utility tools allow lesion assessment, optimal working-view selection for specific vessel segments, and improved guidance via overlay functionality or follow C-arc.

Nanoparticle pharmacokinetic profiling in vivo using magnetic resonance imaging.

Contrast agents targeted to molecular markers of disease are currently being developed with the goal of identifying disease early and evaluating treatment effectiveness using noninvasive imaging modalities such as MRI. Pharmacokinetic profiling of the binding of targeted contrast agents, while theoretically possible with MRI, has thus far only been demonstrated with more sensitive imaging techniques. Paramagnetic liquid perfluorocarbon nanoparticles were formulated to target alpha(v)beta(3)-integrins associated with early atherosclerosis in cholesterol-fed rabbits to produce a measurable signal increase on magnetic resonance images after binding.

Gadolinium-modulated 19F signals from perfluorocarbon nanoparticles as a new strategy for molecular imaging.

Recent advances in the design of fluorinated nanoparticles for molecular magnetic resonance imaging (MRI) have enabled specific detection of (19)F nuclei, providing unique and quantifiable spectral signatures. However, a pressing need for signal enhancement exists because the total (19)F in imaging voxels is often limited. By directly incorporating a relaxation agent, gadolinium (Gd), into the lipid monolayer that surrounds the perfluorocarbon (PFC), a marked augmentation of the (19)F signal from 200-nm nanoparticles was achieved.

Clinical applications of perfluorocarbon nanoparticles for molecular imaging and targeted therapeutics.

Molecular imaging is a novel tool that has allowed non-invasive diagnostic imaging to transition from gross anatomical description to identification of specific tissue epitopes and observation of biological processes at the cellular level. This technique has been confined to the field of nuclear imaging; however, recent advances in nanotechnology have extended this research to include ultrasound (US) and magnetic resonance (MR) imaging. The exploitation of nanotechnology for MR and US molecular imaging has generated several candidate contrast agents.

Nanomedicine opportunities for cardiovascular disease with perfluorocarbon nanoparticles.

Nanomedicine promises to enhance the ability of clinicians to address some of the serious challenges responsible for cardiovascular mortality, morbidity and numerous societal consequences. Targeted imaging and therapy applications with perfluorocarbon nanoparticles are relevant to a broad spectrum of cardiovascular diseases, ranging from asymptomatic atherosclerotic disease to acute myocardial infarction or stroke. As illustrated in this article, perfluorocarbon nanoparticles offer new tools to recognize and characterize pathology, to identify and segment high-risk patients and to treat chronic and acute disease.

Fluorine cardiovascular magnetic resonance angiography in vivo at 1.5 T with perfluorocarbon nanoparticle contrast agents.

While the current gold standard for coronary imaging is X-ray angiography, evidence is accumulating that it may not be the most sensitive technique for detecting unstable plaque. Other imaging modalities, such as cardiovascular magnetic resonance (CMR), can be used for plaque characterization, but suffer from long scan and reconstruction times for determining regions of stenosis. We have developed an intravascular fluorinated contrast agent that can be used for angiography with cardiovascular magnetic resosnace at clinical field strengths (1.

Molecular imaging and therapy of atherosclerosis with targeted nanoparticles.

Advances in bionanotechnology are poised to impact the field of cardiovascular diagnosis and therapy for decades to come. This review seeks to illustrate selected examples of newly developed diagnostic and therapeutic nanosystems that have been evaluated in experimental atherosclerosis, thrombosis, and vascular biology. We review a variety of nanotechnologies that are capable of detecting early cardiovascular pathology, as well as associated imaging approaches and conjunctive strategies for site-targeted treatment with nanoparticle delivery systems.

19F magnetic resonance imaging for stem/progenitor cell tracking with multiple unique perfluorocarbon nanobeacons.

MRI has been employed to elucidate the migratory behavior of stem/progenitor cells noninvasively in vivo with traditional proton (1H) imaging of iron oxide nanoparticle-labeled cells. Alternatively, we demonstrate that fluorine (19F) MRI of cells labeled with different types of liquid perfluorocarbon (PFC) nanoparticles produces unique and sensitive cell markers distinct from any tissue background signal. To define the utility for cell tracking, mononuclear cells harvested from human umbilical cord blood were grown under proendothelial conditions and labeled with nanoparticles composed of two distinct PFC cores (perfluorooctylbromide and perfluoro-15-crown-5 ether).

Endothelial alpha(v)beta3 integrin-targeted fumagillin nanoparticles inhibit angiogenesis in atherosclerosis.

Objective: Angiogenic expansion of the vasa vasorum is a well-known feature of progressive atherosclerosis, suggesting that antiangiogenic therapies may stabilize or regress plaques. Alpha(v)beta3 integrin-targeted paramagnetic nanoparticles were prepared for noninvasive assessment of angiogenesis in early atherosclerosis, for site-specific delivery of antiangiogenic drug, and for quantitative follow-up of response.

Methods And Results: Expression of alpha(v)beta3 integrin by vasa vasorum was imaged at 1.

In vitro demonstration using 19F magnetic resonance to augment molecular imaging with paramagnetic perfluorocarbon nanoparticles at 1.5 Tesla.

Objectives: This study explored the use of F spectroscopy and imaging with targeted perfluorocarbon nanoparticles for the simultaneous identification of multiple bio-signatures at 1.5 T.

Materials And Methods: Two nanoparticle emulsions with perfluoro-15-crown-5-ether (CE) or perfluorooctylbromide (PFOB) cores were targeted in vitro to fibrin clot phantoms (n=12) in 4 progressive ratios using biotin-avidin interactions.

Applications of nanotechnology to atherosclerosis, thrombosis, and vascular biology.

The role of nanotechnology in cardiovascular diagnosis is expanding rapidly. The goal of this brief review is to illustrate selected examples of nanosystems that have been applied to the arenas of atherosclerosis, thrombosis, and vascular biology. The technologies for producing targeted nanosystems are multifarious and reflect end uses in many cases.

1H/19F magnetic resonance molecular imaging with perfluorocarbon nanoparticles.

Developments in genomics, proteomics, and cell biology are leading a trend toward individualized segmentation and treatment of patients based on early, noninvasive recognition of unique biosignatures. Although developments in molecular imaging have been dominated by nuclear medicine agents in the past, the advent of nanotechnology in the 1990s has led to magnetic resonance (MR) molecular agents that allow detection of sparse biomarkers with a high-resolution imaging modality that can provide both physiological and functional agents. A wide variety of nanoparticulate MR contrast agents have emerged, most of which are superparamagnetic iron oxide-based constructs.