Vessel size measurements in angiograms: A comparison of techniques

Abstract

As interventional procedures become more complicated, the need for accurate quantitative vascular information increases. In response to this need, many commercial vendors provide techniques for measurement of vessel sizes, usually based on derivative techniques. In this study, we investigate the accuracy of several techniques used in the measurement of vessel size. Simulated images of vessels having circular cross sections were generated and convolved with various focal spot distributions taking into account the magnification. These vessel images were then convolved with Gaussian image detector line spread functions (LSFs). Additionally, images of a phantom containing vessels with a range of diameters were acquired for the 4.5", 6", 9", and 12" modes of an image intensifier-TV (II-TV) system. Vessel sizes in the images were determined using a first-derivative technique, a second-derivative technique, a linear combination of these two measured sizes, a thresholding technique, a densitometric technique, and a model-based technique. For the same focal spot size, the shape of the focal spot distribution does not affect measured vessel sizes except at large magnifications. For vessels with diameters larger than the full-width-at-half-maximum (FWHM) of the LSF, accurate vessel sizes (errors approximately 0.1 mm) could be obtained by using an average of sizes determined by the first and second derivatives. For vessels with diameters smaller than the FWHM of the LSF, the densitometric and model-based techniques can provide accurate vessel sizes when these techniques are properly calibrated.

CT Brain Perfusion Protocol to Eliminate the Need for Selecting a Venous Output Function

“…This technique proved accurate as long as the vessel diameter was not smaller than the full width at half maximum of the CT images. 25 Selection of the VOF was similar to the selection of the AIF, though now the ROIs were placed over large veins (sagittal sinus) that were approximately perpendicular to the imaging plane. Because the vessel center can be considered least affected by partial volume, the AUC was estimated by fitting a Gaussian curve to the time-attenuation curve of the pixel determined to be at the center.…”

“…17 The content of each region of interest in the raw data was examined to determine the artery diameter and center. The diameter and center were estimated by using a threshold technique, 25 allowing grouping in artery types: ICA (diameter Ն4 mm), MCA (2-3 mm), and smaller arteries (1-2 mm) such as small MCA and anterior cerebral artery vessels. This technique proved accurate as long as the vessel diameter was not smaller than the full width at half maximum of the CT images.…”

Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom

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Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

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