New microangiography system development providing improved small vessel imaging, increased contrast-to-noise ratios, and multiview 3D reconstructions

Abstract

A new microangiographic system (MA) integrated into a c-arm gantry has been developed allowing precise placement of a MA at the exact same angle as the standard x-ray image intensifier (II) with unchanged source and object position. The MA can also be arbitrarily moved about the object and easily moved into the field of view (FOV) in front of the lower resolution II when higher resolution angiographic sequences are needed. The benefits of this new system are illustrated in a neurovascular study, where a rabbit is injected with contrast media for varying oblique angles. Digital subtraction angiographic (DSA) images were obtained and compared using both the MA and II detectors for the same projection view. Vessels imaged with the MA appear sharper with smaller vessels visualized. Visualization of ~100 μm vessels was possible with the MA whereas not with the II. Further, the MA could better resolve vessel overlap. Contrast to noise ratios (CNR) were calculated for vessels of varying sizes for the MA versus the II and were found to be similar for large vessels, approximately double for medium vessels, and infinitely better for the smallest vessels. In addition, a 3D reconstruction of selected vessel segments was performed, using multiple (three) projections at oblique angles, for each detector. This new MA/II integrated system should lead to improved diagnosis and image guidance of neurovascular interventions by enabling initial guidance with the low resolution large FOV II combined with use of the high resolution MA during critical parts of diagnostic and interventional procedures.

Experimental comparison of cone beam CT (CBCT) reconstruction and multiview reconstruction (MVR) for microangiography (MA) detector system

“…There may be occasions, due to the physical spacing, between the imaging detector and the object, being limited when that a full dataset of 360° may not be possible. In this kind of situation, micro-CBCT may not be possible but the MVR technique may be done since it uses only 3 projections [25].…”

“…The pixel size of the XII is 120 μm, and FOV is 4.5 in. The same projections were also obtained using the MA support system assembled on the x-ray unit [25]. The support system enables us the facility to obtain the projections at the same orientation using the XII and the MA, without moving the object and the source.…”

Component analysis of a new solid state x-ray image intensifier (SSXII) using photon transfer and instrumentation noise equivalent exposure (INEE) measurements

“…A schematic of the SSXII prototype module is shown in figure 1. The imaging components are packaged in a light-tight enclosure which can be mounted on a clinical c-arm gantry for combined large field-of-view (FOV) low-resolution imaging with a FPD and high-resolution region-of-interest (ROI) imaging with the SSXII14, 15.…”

LabVIEW graphical user interface for a new high sensitivity, high resolution micro-angio-fluoroscopic and ROI-CBCT system

“…The improved EIGI methods [1,2,3,4] along with the new x-ray imaging detectors [5,6,7,8] are essential tools for the treatment of cerebrovascular diseases (CVD) [3] such as aneurysms and vessel stenoses. Furthermore, improved design of software that automates the radiographic procedures for the above methods and simplifies the job of the radiologist or interventionalist is important for better treatment and more accurate diagnoses.…”