Initial clinical experience of selective coronary angiography using one prolonged injection and a 180° rotational trajectory

Comparison of diagnostic accuracy of dual-axis rotational versus standard coronary angiography

The data about the accuracy of dual-axis rotational coronary angiography (DARCA) in detecting coronary artery disease (CAD) is scare. This study aimed to compare the diagnostic accuracy of DARCA versus standard coronary angiography (SA). 70 patients with possible CAD underwent SA following by DARCA were prospectively enrolled. The primary endpoint was the non-inferiority comparison of the two modalities regarding diagnosis of CAD. Coronary lesion assessment, quantitative coronary angiography (QCA) analysis, and screening adequacy comparisons were performed. All images were analyzed by two independent reviewers except QCA analysis that was analyzed by the third independent reviewer. Radiation dose, contrast usage and procedural time were recorded. This trial is registered with ClinicalTrials.gov, Number NCT01776866. 63 of 70 patients were analyzed. DARCA was non-inferior to SA regarding the diagnosis of CAD (reviewer one-positive agreement: 100%, negative agreement: 100%, p = 1; p = 0.003 for non-inferiority; reviewer two-positive agreement: 96%, negative agreement: 95%, p = 1; p = 0.016 for non-inferiority). All reviewers showed good agreement between the two modalities for the diagnosis of CAD, coronary lesion assessment, QCA analysis, and screening adequacy, as reflected by kappa coefficients between 0.61 and 1.00. DARCA was associated with 41% reduction in radiation dose, 30% in contrast usage and 29% in procedure time (all p < 0.001). DARCA is clinically comparable to SA concerning the diagnostic accuracy for CAD, while markedly reduces radiation dose, contrast usage and procedure time.

Correlation between dual-axis rotational coronary angiography and intravascular ultrasound in a coronary lesion assessment

The purpose of this study was to evaluate the accuracy of dual-axis rotational coronary angiography (DARCA) for coronary lesion assessment by directly comparing with intravascular ultrasound (IVUS). From October 2014 to December 2015, 40 patients (58 lesions) who had undergone both DARCA and IVUS were included in the image analysis. The minimum lumen diameter (MLD), lesion length, reference vessel diameter (RVD) and percent diameter stenosis at the same lesion, were identified and assessed. Significant correlation with IVUS was found for DARCA in either lesion length (r = 0.90, P < 0.001) or RVD (r = 0.81, P < 0.001) comparison. DARCA had fair correlation with IVUS for both MLD (r = 0.65, P < 0.001) and diameter stenosis (r = 0.48, P < 0.001). From the Bland-Altman plots, there was a good agreement between DARCA and IVUS regarding MLD (mean difference: -0.23 mm, 95 % limits of agreement: -0.96 to 0.50 mm) and RVD (mean difference: -0.15 mm, 95 % limits of agreement: -0.85 to 0.55 mm), while lesser agreement was found on lesion length (mean difference: -3.39 mm, 95 % limits of agreement: -12.63 to 5.85 mm) and diameter stenosis (mean difference: 4.82 %, 95 % limits of agreement: -17.05 to 26.68 %). There is an adequate correlation and agreement between DARCA and IVUS in coronary lesion assessment.

A randomized trial comparing dual axis rotational versus conventional coronary angiography in a population with a high prevalence of coronary artery disease

OBJECTIVES

To compare the safety, radiation dose, and contrast volume between dual axis rotational coronary angiography (DARCA) and conventional coronary angiography (CCA).

BACKGROUND

CCA is performed in multiple, predefined stationary views, at different angulations around the patient, for both the left and right coronary arteries. DARCA (AlluraXperSwing™, Philips, the Netherlands) involves a pre-set rotation of the C-arm around the patient and allows for the visualization of each coronary artery in different views, using a single automatic pump contrast injection.

METHODS

From November 2012 to February 2013, 201 patients were randomly assigned to either CCA (n = 100) or DARCA (n = 101). Exclusion criteria included acute coronary syndrome (ACS), prior PCI or CABG. CCAs were performed in 4 acquisition runs for the left coronary artery and 2 to 3 acquisition runs for the right coronary artery, whereas DARCAs were performed in a single run for each coronary artery.

RESULTS

Baseline demographics and clinical characteristics were similar for both groups. The overall prevalence of CAD was 77.6%. The DARCA group had a significant reduction in the amount of contrast, 60 ml (IQR: 52.5-71.5 ml) versus 76 ml (IQR: 68-87 ml), P < 0.0001; and radiation dose by Air Kerma, 269.5 mGy (IQR: 176-450.5) versus 542.1 mGy (IQR: 370.7-720.8), P < 0.0001. There were fewer patients requiring additional projections in the DARCA group: 54.0% versus 75.0%; P = 0.002.

CONCLUSIONS

In a population with a high prevalence of CAD, DARCA was safe and resulted in a significant decrease in contrast volume and radiation dose.

Comparison of a safety strategy using transradial access and dual-axis rotational coronary angiography with transfemoral access and standard coronary angiography

OBJECTIVES

We sought to investigate the radiation exposure and contrast utilization associated with using a strategy of transradial access and rotational angiography (radial-DARCA) compared to the traditional approach of transfemoral access and standard angiography (femoral-SA).

BACKGROUND

There is an increased focus on optimizing patient safety during cardiac catheterization procedures. Professional guidelines have highlighted physician responsibility to minimize radiation doses and contrast volume. Dual axis rotational coronary angiography (DARCA) is the most recently investigated type of rotational angiography. This new technique permits complete visualization of the left or right coronary tree with a single injection, and is felt to reduce contrast and radiation exposure.

METHODS

A total of 56 consecutive patients who underwent radial-DARCA were identified. From the same time period, an age- and gender-matched group of 61 patients who had femoral-SA were selected for comparison. Total volume of contrast agent used, fluoroscopy time, and 2 measures of radiation dose (dose area product and air kerma) were recorded for each group.

RESULTS

Mean contrast agent use and patient radiation exposure of the radial-DARCA group were significantly less than that of the femoral-SA group. There was no significant difference in fluoroscopy time between the 2 groups.

CONCLUSIONS

Physicians can successfully employ an innovative safety strategy of transradial access combined with DARCA that is feasible and is associated with lower radiation doses and contrast volume than femoral artery access and traditional coronary angiography approach.

Dual-axis rotational coronary angiography: a new technique for detecting graft coronary vasculopathy in pediatric heart transplant recipients

Annual surveillance coronary angiograpyhy to screen for graft coronary vasculopathy is routine practice after orthotopic heart transplantation. Traditionally, this is performed with direct coronary angiography using static single-plane or biplane angiography. Recently, technological advances have made it possible to perform dual-axis rotational coronary angiography (RA). This technique differs from standard static single-plane or biplane angiography in that a single detector is preprogrammed to swing through a complex 80° arc during a single injection. It has the advantage of providing a perspective of the vessels from a full arc of images rather than from one or two static images per contrast injection. The current study evaluated two coronary angiography techniques used consecutively at a single center to evaluate pediatric heart transplant recipients for graft coronary vasculopathy. A total of 23 patients underwent routine coronary angiography using both biplane static coronary angiography (BiP) and RA techniques at the Children's Hospital of Wisconsin from February 2009 to September 2010. Demographic and procedure data were collected from each procedure and analyzed for significance utilizing a Wilcoxon rank sum test. No significant demographic or procedural differences between the BiP and the RA procedures were noted. Specific measures of radiation dose including fluoroscopy time and dose area product were similar among the imaging techniques. The findings show that RA can be performed safely and reproducibly in pediatric heart transplant recipients. Compared with standard BiP, RA does not increase radiation exposure or contrast use and in our experience has provided superior angiographic imaging for the evaluation of graft coronary vasculopathy.

Comparison of dual-axis rotational coronary angiography (XPERSWING) versus conventional technique in routine practice

INTRODUCTION AND OBJECTIVES

Coronary angiography is the gold standard for the study of coronary artery disease. This technique requires several orthogonal projections. Rotational angiography is a new technique which involves pre-set rotation of the X-ray tube around the patient and allows visualization of each coronary artery in different views, using a single contrast injection. The purpose of this study was to compare conventional coronary angiography (A) vs rotational angiography (B), focusing on radiation dose, amount of contrast administered, and total procedure time for both diagnostic and therapeutic percutaneous coronary interventions.

METHODS

Prospective study of 104 consecutive patients undergoing coronary angiography who were randomized to one of these techniques.

RESULTS

We found a significant reduction in the amount of contrast administered (A vs B, 93.1 [41.7] vs 50.9 [14.7] mL; P<.0001) and radiation exposure (27.6 [11.5] vs 18 [6.4] mGycm(2); P<.0001). A significant increase in total procedure time was noted in the rotational angiography arm. However, when only the last 50 patients were analyzed, we found no difference in procedure time between the groups, probably related to the learning curve of the operators. Angioplasty was performed in 29 patients in group A and 28 patients in group B. Contrast reduction was maintained in the rotational angiography group compared to the conventional technique (A vs B, 335.1 [192.1] vs 238.5 [114.4] mL; P=.02).

CONCLUSIONS

The rotational angiography technique leads to a significant decrease in radiation exposure and contrast dose administered for diagnostic procedures when compared to conventional coronary angiography. In patients who undergo percutaneous coronary intervention, contrast reduction remains significant.

Safety and efficacy of dual-axis rotational coronary angiography vs. standard coronary angiography

OBJECTIVE

To determine the safety and efficacy of dual-axis rotational coronary angiography (DARCA) by directly comparing it to standard coronary angiography (SA).

BACKGROUND

Standard coronary angiography (SA) requires numerous fixed static images of the coronary tree and has multiple well-documented limitations. Dual-axis rotational coronary angiography (DARCA) is a new rotational acquisition technique that entails simultaneous LAO/RAO and cranial/caudal gantry movement. This technological advancement obtains numerous unique images of the left or right coronary tree with a single coronary injection. We sought to assess the safety and efficacy of DARCA as well as determine DARCA's adequacy for CAD screening and assessment.

METHODS

Thirty patients underwent SA following by DARCA. Contrast volume, radiation dose (DAP) and procedural time were recorded for each method to assess safety. For DARCA acquisitions, blood pressure (BP), heart rate (HR), symptoms and any arrhythmias were recorded. All angiograms were reviewed for CAD screening adequacy by two independent invasive cardiologists.

RESULTS

Compared to SA, use of DARCA was associated with a 51% reduction in contrast, 35% less radiation exposure, and 18% shorter procedural time. Both independent reviewers noted DARCA to be at least equivalent to SA with respect to the ability to screen for CAD.

CONCLUSION

DARCA represents a new angiographic technique which is equivalent in terms of image quality and is associated with less contrast use, radiation exposure, and procedural time than SA.

Comparison of rotational with conventional coronary angiography

BACKGROUND

Patient radiation exposure and consumption of contrast medium are considered major risks of diagnostic coronary angiography (CA). Rotation of the C-arm during CA could provide similar diagnostic accuracy and lower radiation exposure and contrast medium consumption.

METHODS

To compare feasibility, safety, diagnostic accuracy, patient radiation exposure, and consumption of contrast medium of rotational CA with the invasive standard technique, intraindividual comparisons of the results obtained by both techniques were performed in 235 patients with an indication for first-time elective CA. In addition to conventional angiography, we performed 2 isocentric radiographic coronary spins with cranial and caudal tilts by 20 degrees around the left coronary artery and 1 strict posteroanterior rotational spin around the right coronary artery.

RESULTS

In 16 patients, rotational CA was not performed because of safety concerns. In a further 12 patients, image quality of rotational scans was considered inadequate. In the remaining 207 patients, both modes of CA were proven suitable for anonymized, separate analysis by 3 independent cardiologists. Intraindividual comparison of both CA modes revealed a high degree of diagnostic agreement (Cohen (K) >0.8 for all cardiologists and for each coronary segment). Contrast medium volume during rotational CA and conventional CA amounted to 31.9 +/- 4.5 mL versus 52.2 +/- 8.0 mL (P < .001) and patient radiation exposure amounted to 5.0 +/- 2.6 Gy × cm(2) versus 11.5 +/- 5.5 Gy × cm(2) (P < .001), respectively.

CONCLUSIONS

Rotational CA represents a safe and feasible method in clinical routine. Whereas diagnostic accuracy is similar to the usual conventional mode, consumption of contrast medium and patient radiation exposure are significantly reduced.

Clinical feasibility of a fully automated 3D reconstruction of rotational coronary X-ray angiograms

BACKGROUND

Although fixed view x-ray angiography remains the primary technique for anatomic imaging of coronary artery disease, the known shortcomings of 2D projection imaging may limit accurate 3D vessel and lesion definition and characterization. A recently developed method to create 3D images of the coronary arteries uses x-ray projection images acquired during a 180 degrees C-arm rotation and continuous contrast injection followed by ECG-gated iterative reconstruction. This method shows promise for providing high-quality 3D reconstructions of the coronary arteries with no user interaction but requires clinical evaluation.

METHODS AND RESULTS

The reconstruction strategy was evaluated by comparing the reconstructed 3D volumetric images with the 2D angiographic projection images from the same 23 patients to ascertain overall image quality, lesion visibility, and a comparison of 3D quantitative coronary analysis with 2D quantitative coronary analysis. The majority of the resulting 3D volume images were rated as having high image quality (66%) and provided the physician with additional clinical information such as complete visualization of bifurcations and unobtainable views of the coronary tree. True-positive lesion detection rates were high (90 to 100%), whereas false-positive detection rates were low (0 to 8.1%). Finally, 3D quantitative coronary analysis showed significant similarity with 2D quantitative coronary analysis in terms of lumen diameters and provided vessel segment length free from the errors of foreshortening.

CONCLUSIONS

Fully automated reconstruction of rotational coronary x-ray angiograms is feasible, produces 3D volumetric images that overcome some of the limitations of standard 2D angiography, and is ready for further implementation and study in the clinical environment.

Rotational coronary angiography

The numerous well-documented limitations of standard fixed-acquisition coronary angiography led to the development of rotational angiography. This acquisition method uses automated gantry movements while numerous angiographic projections are obtained, and thus overcomes many of the limitations of standard angiography. This article highlights the techniques, advantages, and disadvantages of each type of rotational angiography currently commercially available. Also included is a discussion of the evolution of rotational angiography, from its initial conception and pilot studies to its latest step forward on the developmental road towards enhanced coronary imaging.

Computer assistance for solving imaging problems

Medical imaging has moved into an era of digital files and processing of images to yield three-dimensional models and reconstructions. This development has opened up opportunities to apply computer techniques in traditional imaging tasks. Two of the most common imaging tasks are those to correct the two-dimensional projection problems of foreshortening of lesions and of vessel overlap. This article explores the use of computers to assist in these tasks, to create databases for guiding decision making, to provide graphics to assist the physician, and to simulate cardiovascular procedures.

A framework for geometric analysis of vascular structures: application to cerebral aneurysms

There is well-documented evidence that vascular geometry has a major impact in blood flow dynamics and consequently in the development of vascular diseases, like atherosclerosis and cerebral aneurysmal disease. The study of vascular geometry and the identification of geometric features associated with a specific pathological condition can therefore shed light into the mechanisms involved in the pathogenesis and progression of the disease. Although the development of medical imaging technologies is providing increasing amounts of data on the three-dimensional morphology of the in vivo vasculature, robust and objective tools for quantitative analysis of vascular geometry are still lacking. In this paper, we present a framework for the geometric analysis of vascular structures, in particular for the quantification of the geometric relationships between the elements of a vascular network based on the definition of centerlines. The framework is founded upon solid computational geometry criteria, which confer robustness of the analysis with respect to the high variability of in vivo vascular geometry. The techniques presented are readily available as part of the VMTK, an open source framework for image segmentation, geometric characterization, mesh generation and computational hemodynamics specifically developed for the analysis of vascular structures. As part of the Aneurisk project, we present the application of the present framework to the characterization of the geometric relationships between cerebral aneurysms and their parent vasculature.

Determination of optimal viewing regions for X-ray coronary angiography based on a quantitative analysis of 3D reconstructed models

Current expert-recommended views for coronary angiography are based on heuristic experience and have not been scientifically studied. We sought to identify optimal viewing regions for first and second order vessel segments of the coronary arteries that provide optimal diagnostic value in terms of minimizing vessel foreshortening and overlap. Using orthogonal 2D images of the coronary tree, 3D models were created from which patient-specific optimal view maps (OVM) allowing quantitative assessment of vessel foreshortening and overlap were generated. Using a novel methodology that averages 3D-based optimal projection geometries, a universal OVM was created for each individual coronary vessel segment that minimized both vessel foreshortening and overlap. A universal OVM model for each coronary segment was generated based on data from 137 patients undergoing coronary angiography. We identified viewing regions for each vessel segment achieving a mean vessel foreshortening value of 5.8 +/- 3.9% for the left coronary artery (LCA) and 5.6 +/- 3.6% for the right coronary artery (RCA). The overall mean overlap values achieved were 8.7 +/- 7.9% for the LCA and 4.6 +/- 3.2% for the RCA. This scientifically-based OVM evaluation of coronary vessel segments provides the means to facilitate acquisitions during coronary angiography and interventions that minimize imaging inaccuracies related to foreshortening and overlap, improving the accuracy, efficiency, and safety of diagnostic and interventional coronary procedures.

Can we finally get a coronary angiography with the least amount of dye?

The incidence of adverse events complicating coronary angiography is still considerably high. Founded concerns about risks of coronary angiography, and mainly its inherent invasiveness, have favored the increasing request for noninvasive techniques to evaluate the coronary anatomy, such as multislice computed tomography (MSCT). Nonetheless, it has to be kept in mind that several risks and complications are the same both for MSCT and conventional coronary angiography. Rotational angiography has been shown to be a powerful imaging tool for the evaluation of coronary anatomy resulting in the use of less contrast media and less radiation, without losing the possibility to obtain a precise, efficient and fast characterization of obstructive coronary artery disease. It is likely that in the next future the overall performance, taking into account both the diagnostic accuracy and the risk of exposure to radiation and contrast media, of MSCT techniques will have to be compared to that of rotational angiography, especially when the latter is coupled with minimally invasive approaches.