WE‐DE‐207A‐04: Advances in Radiological Neuro‐Endovascular Interventional Imaging
Authors: Rudin S. 
Published: July 2016

1. Parallels in the evolution of x‐ray angiographic systems and devices used for minimally invasive endovascular therapy

Charles Strother ‐ DSA, invented by Dr. Charles Mistretta at UW‐Madison, was the technology which enabled the development of minimally invasive endovascular procedures. As DSA became widely available and the potential benefits for accessing the cerebral vasculature from an endovascular approach began to be apparent, industry began efforts to develop tools for use in these procedures. Along with development of catheters, embolic materials, pushable coils and the GDC coils there was simultaneous development and improvement of 2D DSA image quality and the introduction of 3D DSA. Together, these advances resulted in an enormous expansion in the scope and numbers of minimally invasive endovascular procedures.

The introduction of flat detectors for c‐arm angiographic systems in 2002 provided the possibility of the angiographic suite becoming not just a location for vascular imaging where physiological assessments might also be performed. Over the last decade algorithmic and hardware advances have been sufficient to now realize this potential in clinical practice. The selection of patients for endovascular treatments is enhanced by this dual capability. Along with these advances has been a steady reduction in the radiation exposure required so that today, vascular and soft tissue images may be obtained with equal or in many cases less radiation exposure than is the case for comparable images obtained with multi‐detector CT.

Learning Objectives:

To understand the full capabilities of today's angiographic suite

To understand how c‐arm cone beam CT soft tissue imaging can be used for assessments of devices, blood flow and perfusion.

Advances in real‐time x‐ray neuro‐endovascular image guidance

Stephen Rudin ‐ Reacting to the demands on real‐time image guidance for ever finer neurovascular interventions, great improvements in imaging chains are being pursued. For the highest spatial and temporal resolution, x‐ray guidance with fluoroscopy and angiography although dominant are still being vastly improved. New detectors such as the Micro‐Angiographic Fluoroscope (MAF) and x‐ray source designs that enable higher outputs while maintaining small focal spots will be highlighted along with new methods for minimizing the radiation dose to patients. Additionally, new platforms for training and device testing that include patient‐specific 3D printed vascular phantoms and new metrics such as generalized relative object detectability for objectively inter‐comparing systems will be discussed. This will improve the opportunity for better evaluation of these technological advances which should contribute to the safety and efficacy of image guided minimally invasive neuro‐endovascular procedures.

Learning Objectives:

To understand the operation of new x‐ray imaging chain components such as detectors and sources

To be informed about the latest testing methods, with 3D printed vascular phantoms, and new evaluation metrics for advanced imaging in x‐ray image guided neurovascular interventions

Advances in cone beam CT anatomical and functional imaging in angio‐suite to enable one‐stop‐shop stroke imaging workflow

Guang‐Hong Chen ‐ The introduction of flat‐panel detector based cone‐beam CT in clinical angiographic imaging systems enabled treating physicians to obtain three‐dimensional anatomic roadmaps for bony structure, soft brain tissue, and vasculatures for treatment planning and efficacy checking after the procedures. However, much improvement is needed to reduce image artifacts, reduce radiation dose, and add potential functional imaging capability to provide four‐dimensional dynamic information of vasculature and brain perfusion. In this presentation, some of the new techniques developed to address radiation dose issues, image artifact reduction and brain perfusion using C‐arm cone‐beam CT imaging system will be introduced for the audience.

Learning Objectives:

To understand the clinical need of one‐stop‐shop stroke imaging workflow

To understand to technical challenges in cone beam CT perfusion

To understand the potential technical solutions to enable one‐stop‐shop imaging workflow

Recent advances in devices used in neuro‐‐interventions

Mattew Gounis ‐ Over the past two decades, there has been explosive development of medical devices that have revolutionized the endovascular treatment of cerebrovascular diseases. There is now Level 1, Class A evidence that intra‐arterial, mechanical thrombectomy in acute ischemic stroke is superior to medical management; and similarly that minimally invasive, endovascular repair of ruptured brain aneurysms is superior to surgical treatment. Stent‐retrievers are now standard of care for emergent large vessel occlusions causing a stroke, with a number of patients need to treat for good clinical outcomes as low as 4. Recent technologies such as flow diverters and disrupters, intracranial self‐expanding stents, flexible large bore catheters that can reach vessels beyond the circle of Willis, stent‐retrievers, and super‐compliant balloons are the result of successful miniaturization of design features and novel manufacturing technologies capable of building these devices. This is a rapidly evolving field, and the device technology enabling such advancements will be reviewed. Importantly, image‐guidance technology has not kept pace in neurointervention and the ability to adequately characterize these devices in vivo remains a significant opportunity.

Learning Objectives:

A survey of devices used in neurointerventions, their materials and essential design characteristics

Funding support received from NIH and DOD; Funding support received from GE Healthcare; Funding support received from Siemens AX; Patent royalties received from GE Healthcare; G. Chen, Funding received from NIH; funding received from DOD; funding received from GE Healthcare; funding received from Siemens AX.; M. Gounis, consultant for Codman Neurovascular and Stryker Neurovascular; Holds stock in InNeuroCo Inc, research grants: NIH, Medtronic Neurovascular, Microvention/Terumo, Cerevasc LLC, Gentuity, Codman Neurovascular, Philips Healthcare, Stryker Neurovascular, Tay Sachs Foundation, and InNeuroCo Inc.; S. Rudin, Supported in part by NIH Grant R01EB002873 and the Toshiba Medical System Corp.