Relationship Between the Contrast Effects of Raw Data Projection Images from Three-Dimensional Digital Subtraction Angiography and the Optimal Volume Rendering Parameters

Abstract

Volume rendering (VR) is a technique commonly used for the reconstruction of three-dimensional (3D) digital subtraction angiography (DSA) images, and the rendering parameters greatly affect the characteristics of the 3D image. This study aimed to test whether the optimal VR parameters for 3D DSA could be estimated from the contrast effects in rotational two-dimensional (2D) DSA images acquired using 3D DSA. Simulated blood vessels filled with various concentrations of contrast medium were scanned, and the 3D DSA data sets were reconstructed. The syngo AX vessel analysis software that was able to analyze 3D DSAVR image was used for objective measures. Raw data projection images of the 3D DSA data sets in which the mean diameter was calculated as a true value by the software at nine different thresholds for vessel segmentation were selected. In each image set, five images of all 133 rotational 2D DSA images were selected, and the contrast-enhanced area was extracted using a regiongrowing algorithm. Mean values and standard deviations of each contrast-enhanced area were calculated, and as the thresholds for vessel segmentation of the software increased by 500 every time, significant differences were observed in the mean values (P<0.01). This optimal threshold can be applied to the window settings of the VR technique. Therefore, the optimal VR parameters for 3D DSA may be determined by analyzing the contrast effects of the raw data projection images, and user-dependent over-and underestimations of 3D DSA VR images also may be prevented.

Relationship between Injection Rate and Contrast Enhancement on Three-dimensional Digital Subtraction Angiography of the Cerebral Arteries

“…Three-dimensional DSA images are finally reconstructed to derive 3D VR images. The rendering parameters greatly affect the characteristics of the 3D VR image, and the relationship between the contrast effects of 3D DSA and optimal VR parameters has been reported [ 13 ]. Inadequate rendering parameters can lead to over-estimation or under-estimation of lumen diameter.…”

“…The quality of the 3D volume rendering (VR) image is affected by the reconstruction and rendering parameters [ 13 ]. Therefore, we analyzed the rotational 2D DSA images that were the source of the 3D DSA images.…”