X-ray videodensitometric methods for blood flow and velocity measurement: A critical review of literature

Abstract

Blood flow rate and velocity are important parameters for the study of vascular systems, and for the diagnosis, monitoring and evaluation of treatment of cerebro- and cardiovascular disease. For rapid imaging of cerebral and cardiac blood vessels, digital x-ray subtraction angiography has numerous advantages over other modalities. Roentgen-videodensitometric techniques measure blood flow and velocity from changes of contrast material density in x-ray angiograms. Many roentgen-videodensitometric flow measurement methods can also be applied to CT, MR and rotational angiography images. Hence, roentgen-videodensitometric blood flow and velocity measurement from digital x-ray angiograms represents an important research topic. This work contains a critical review and bibliography surveying current and old developments in the field. We present an extensive survey of English-language publications on the subject and a classification of published algorithms. We also present descriptions and critical reviews of these algorithms. The algorithms are reviewed with requirements imposed by neuro- and cardiovascular clinical environments in mind.

Analysis of Intra-Aneurysmal Flow for Cerebral Aneurysms with Cerebral Angiography

“…DSA has been used for flow quantification before, and it has been used by others for velocity measurement, [16][17][18] and aneurysmal flow evaluation. [9][10][11] These studies demonstrate that the change of signal does have a potential to assist us in understanding the hemodynamics in arteries and aneurysms.…”

Analysis of the Influence of 4D MR Angiography Temporal Resolution on Time-to-Peak Estimation Error for Different Cerebral Vessel Structures

“…It has been shown that this parameter leads to better results 12 compared with other criteria, such as the time-to-maximum-slope parameter. An overview of typically used alternative bolus arrival time criteria is, for example, given by Shpilfoygel et al 13 The TTP parameter is especially important for 4D MRA imaging techniques because it reflects the temporal distribution of the contrast agent and can, therefore, be used as an indirect estimate of the blood flow velocity. Due to the discrete IDC representation, recirculation effects, and noise artifacts, which affect the shape of the curves, the direct estimation of the TTP parameter is often imprecise.…”

Estimating blood flow velocity in angiographic image data

“…6 Concentration Time Curves (CTC) track the bolus propagation by observing the change of pixel intensity ( Fig. 2(a)) while Concentration Distance Curves (CDC) track the front propagation of the bolus.…”

“…An extensive review of recovering blood flow velocity from projective images was done by Shpilfoygel et al 6 A method similar to our approach was published by Schmitt et al 7 The work aims at determining the contrast agent (CA) propagation in vessel trees. The method also relies on a re-projection of 2D-DSA images to 3D-RA volumes.…”