Quantitative Vascular Analysis Research Articles

3-D Quantitative Vascular Shape Analysis for Arterial Bifurcations via Dynamic Tube Fitting

Reliable and reproducible estimation of vessel centerlines and reference surfaces is an important step for the assessment of luminal lesions. Conventional methods are commonly developed for quantitative analysis of the "straight" vessel segments and have limitations in defining the precise location of the centerline and the reference lumen surface for both the main vessel and the side branches in the vicinity of bifurcations. To address this, we propose the estimation of the centerline and the reference surface through the registration of an elliptical cross-sectional tube to the desired constituent vessel in each major bifurcation of the arterial tree. The proposed method works directly on the mesh domain, thus alleviating the need for image upsampling, usually required in conventional volume domain approaches. We demonstrate the efficiency and accuracy of the method on both synthetic images and coronary CT angiograms. Experimental results show that the new method is capable of estimating vessel centerlines and reference surfaces with a high degree of agreement to those obtained through manual delineation. The centerline errors are reduced by an average of 62.3% in the regions of the bifurcations, when compared to the results of the initial solution obtained through the use of mesh contraction method.

Quantitative impact of cardiovascular risk factors and vascular closure devices on the femoral artery after repeat cardiac catheterization

We evaluated the exact quantitative long-term impact of repeated catheterizations, vascular closure devices, and cardiovascular risk factors on the femoral artery after cardiac catheterization. A total of 2,102 available femoral angiograms from 827 consecutive patients were analyzed using caliper-based quantitative vascular analysis. These patients underwent coronary interventions between January 2005 and April 2007 and had at least one additional catheterization procedure through the ipsilateral femoral access site from December 2001 until January 2008. Multivariate analysis was performed to control for confounding variables. The primary outcome was change in artery size. The average punctured artery diameter was 6.5 +/- 2.1 mm. The average time between the first case and last follow-up was 349 days. There was no significant change of the punctured artery size over time after the index procedure (P = .15) and no change associated with the use of vascular closure devices (P = .25) after multivariate analysis. Smaller arteries were associated with female gender (-1.22 mm, P < .0001), presence of angiographic peripheral vascular disease (PVD, -1.19 mm, P < .0001), and current (-0.48 mm, P = .001) or former (-0.23 mm, P = .01) smoking status, whereas previous statin therapy was associated with an increase in artery size (+0.47 mm, P < .0001). Vascular closure devices were used less often compared with manual compression in cases preceding the first detection of angiographic PVD (P < .001). Vascular closure devices are not associated with a change in the artery size or progression of PVD. Overall, there is no change in vessel size over time after repeat catheterizations, with a decrease in vessel size associated with current and former smoking and an increase with previous statin therapy.

New approaches for the assessment of vessel sizes in quantitative (cardio-)vascular X-ray analysis

This paper presents new approaches for the assessment of the arterial and reference diameters in (cardio-)vascular X-ray images, designed to overcome the problems experienced in conventional quantitative coronary and vascular angiography approaches. In single or “straight” vessel segments, the arterial and reference diameter directions were made independent of each other in order to be able to measure the minimal lumen diameter (MLD) more accurately, especially in curved vessel segments. For ostial segments, an extension of this approach was used, to allow measurement of ostial lesions in sidebranches more proximal than using conventional methods. Furthermore, two new bifurcation approaches were developed. The validation study shows that the straight segment approach results in significant smaller MLDs (on average 0.032 mm) and the ostial approach achieves on average an increase in %DS of 3.8% and an increase in lesion length of 0.59 mm due to loosening the directional constraint. The validation of our new bifurcation approaches in phantom data as well as clinical data shows only small differences between pre- and post-intervention measurements of the reference diameters outside the bifurcation core (errors smaller than 0.06 mm) and the bifurcation core area (errors smaller than 1.4% for phantom data). In summary, these new approaches have led to further improvements in the quantitative analyses of (cardio-)vascular X-ray angiographies.

Risk Predictors of Retroperitoneal Hemorrhage Following Percutaneous Coronary Intervention

Retroperitoneal hemorrhage (RPH) is a potentially catastrophic complication after percutaneous coronary intervention (PCI). Previous studies identified female gender, body surface area, and high arterial puncture location as independent risk factors for RPH. There have been conflicting reports regarding the association with vascular closure devices (VCDs). Chronic renal insufficiency (CRI) and diabetes mellitus have been associated with both peripheral vascular disease and vascular access-site complications. The putative association of VCDs, CRI, and diabetes mellitus with RPH in the contemporary PCI era was investigated. A total of 3,062 consecutive patients undergoing 3,482 PCIs at Brigham and Women's Hospital from January 2005 to April 2007 were evaluated for the study. All 3,311 patients with femoral angiography underwent hand-caliper-based quantitative vascular analysis and were included in this analysis. Multivariate analysis was performed using a backwards selection algorithm, and a propensity adjustment was developed to control for possible confounding variables regarding VCD use. The incidence of RPH was 0.49% (17 of 3,482 patients). After multivariate and propensity analyses, covariates that significantly influenced the risk of RPH were CRI, glycoprotein IIb/IIIa inhibitors, and high arterial puncture (p < or =0.007). VCD use was not independently associated with the development of RPH (p = 0.74). In conclusion, this large prospective cohort study identified CRI, but not VCD use, as an independent predictor for RPH and peripheral vascular disease.

Quantitative contrast enhanced magnetic resonance imaging for the evaluation of peripheral arterial disease: a comparative study versus standard digital angiography

The purpose of this study is to evaluate the accuracy of semiautomated analysis of contrast enhanced magnetic resonance angiography (MRA) in patients who have undergone standard angiographic evaluation for peripheral vascular disease (PVD). Magnetic resonance angiography is an important tool for evaluating PVD. Although this technique is both safe and noninvasive, the accuracy and reproducibility of quantitative measurements of disease severity using MRA in the clinical setting have not been fully investigated. 43 lesions in 13 patients who underwent both MRA and digital subtraction angiography (DSA) of iliac and common femoral arteries within 6 months were analyzed using quantitative magnetic resonance angiography (QMRA) and quantitative vascular analysis (QVA). Analysis was repeated by a second operator and by the same operator in approximately 1 month time. QMRA underestimated percent diameter stenosis (%DS) compared to measurements made with QVA by 2.47%. Limits of agreement between the two methods were +/- 9.14%. Interobserver variability in measurements of %DS were +/- 12.58% for QMRA and +/- 10.04% for QVA. Intraobserver variability of %DS for QMRA was +/- 4.6% and for QVA was +/- 8.46%. QMRA displays a high level of agreement to QVA when used to determine stenosis severity in iliac and common femoral arteries. Similar levels of interobserver and intraobserver variability are present with each method. Overall, QMRA represents a useful method to quantify severity of PVD.

Validation of a new method for the detection of pathlines in vascular x-ray images.

This article presents the validation of a new pathline approach, based on the wavefront propagation principle, on a large variety of vascular images. The purpose of the novel approach, called wavepath, was to minimize the variability of the measurements in the quantitative vascular analysis by reducing the variability that is introduced by manually placing the start and end points of the vessel segment. This results in a robust and reproducible pathline detection that is subsequently used in the analysis and lesion quantification. The validation study that was performed concerned a large variety of vessel segments and showed that the approach results in a pathline that is totally constant in its middle part. This holds not only for the straight segment version but also for the bifurcation version and ostial version of the algorithm. Moreover, the average number of additional points per pathline needed to guide the wavepath through the correct vessel is minimized to 0 for the straight segments, 0.06 for aortic bifurcations, 0.25 for carotid bifurcations, and 0.08 for the ostial segments. In conclusion, our new approach performs very well in all types of vascular x-ray images, resulting in a stable and robust pathline detection.