A comparison between dual axis rotational coronary angiography and conventional coronary angiography

Usefulness of dual-axis rotational coronary angiography in primary percutaneous coronary intervention for patients with ST-elevation myocardial infarction

Several studies have shown that dual-axis rotational coronary angiography (DARCA) reduces contrast medium volume and radiation exposure compared to conventional coronary angiography (CCA). However, there are no studies comparing the safety and usefulness of DARCA in primary percutaneous coronary intervention (PCI) for patients with ST-elevation myocardial infarction (STEMI). The aim of this study was to investigate the effects of DARCA on contrast medium volume, radiation exposure, time course of treatment, and adverse events in primary PCI for patients with STEMI. A total of 82 patients undergoing primary PCI were included in this study. Subjects were propensity matched to 41 patients in the CCA group and 41 in the DARCA group. Data were retrospectively collected from in-patient medical records and the contrast medium volume and radiation exposure (dose-area product, DAP) during the PCI procedure was compared between the two groups. Contrast medium volume [100.0 (82.5-115.0) vs 110 (102.5-127.5) ml, p = 0.018, r = 0.26] and DAP [113.4 (74.3-141.1) vs 138.1 (100.5-194.7) Gy cm2, p = 0.014, r = 0.27] were significantly lower in the DARCA group, compared with the CCA group. Door to device time (68.7 ± 26.1 vs 76.5 ± 44.2 min, p = 0.33) were comparable between the two groups. There were no adverse events requiring treatment reported in either groups. DARCA may reduce contrast medium volume and radiation exposure in primary PCI for patients with STEMI, and can be used safely, without delaying reperfusion of the infarct-related coronary artery.

A randomised comparison of monoplane versus biplane fluoroscopy in patients undergoing percutaneous coronary intervention: the RAMBO trial

AIMS

Interventional cardiologists are exposed to substantial occupational ionising radiation. This study sought to investigate differences in radiation exposure in biplane versus monoplane coronary angiography and percutaneous coronary interventions (PCI).

METHODS AND RESULTS

RAMBO (RAdiation exposure in Monoplane versus Biplane cOronary angiography and interventions) was a prospective, randomised, two-arm, single-centre, open-label trial, enrolling a total of 430 patients undergoing coronary angiography. Patients were randomly assigned to biplane or monoplane imaging. The primary efficacy measure, the operator radiation dose at the level of the left arm as measured by a wearable electronic dosimeter, was significantly higher in the biplane as compared to the monoplane group (4 [1-13] µSv vs 2 [0-6.8] µSv, p<0.001). The dose area product was 11,955 (7,095-18,246) mGy*cm2 and 8,349 (5,851-14,159) mGy*cm2 in the biplane and the monoplane groups, respectively (p<0.001). While fluoroscopy time did not differ between the groups (p=0.89), the amount of contrast medium was lower with biplane as compared with monoplane imaging (p<0.001).

CONCLUSIONS

Biplane imaging for coronary angiography and PCI is related to an increased radiation exposure for the interventional cardiologist as compared with monoplane imaging. Monoplane imaging should be considered for advanced radioprotection in cardiac catheterisation, with biplane imaging used for selected cases only.

Dual-axis rotational coronary angiography versus conventional coronary angiography: a randomized comparison

BACKGROUND

Dual-axis of rotational coronary angiography (RA), with one single cine acquisition during continuous C-arm motion along a pre-described path, is an alternative to conventional coronary angiography (CA). We assessed the performance of RA versus CA in a modern, experienced cath lab setting.

METHODS

Sixty-seven patients with suspected coronary artery disease undergoing invasive coronary angiography were randomized to CA (n = 35) or dual-axis RA (n = 32). CA was performed with four left and two right coronary artery acquisitions with manual contrast medium injection. In RA, one cine acquisition each was performed for the left (5 projections) and right coronary artery (3 projections) with a fixed amount of contrast medium applied by a power injector. In both groups, single cine acquisitions in additional angulations were performed to fully interpret the coronary system, if necessary. Procedural parameters and outcome were compared.

RESULTS

Mean age was 63 ± 12 years (64% males). Six additional projections were required in the RA group compared to 13 in the CA group (p = 0.173). Fluoroscopy duration (CA: 3 ± 3 min, RA: 3 ± 2 min, p = 0.748) and dose area product (CA: 1291 ± 761 µGym², RA: 1476 ± 679 µGym², p = 0.235) did not differ significantly between both groups. For CA, the amount of contrast medium (42 ± 13 vs. 46 ± 8 ml, p = 0.022) and procedure time (8 ± 5 vs. 11 ± 3 min, p < 0.001) were significantly lower. No major adverse event occurred during hospital stay.

CONCLUSIONS

Dual-axis RA represents a feasible and safe alternative method to CA for obtaining coronary angiograms. However, no superiority was observed when performed by an experienced interventionalist with a modern system.

Combining Optimized Image Processing With Dual Axis Rotational Angiography: Toward Low-Dose Invasive Coronary Angiography

Background

Dual axis rotational coronary angiography (DARCA) reduces radiation exposure during coronary angiography on older x‐ray systems. The purpose of the current study is to quantify patient and staff radiation exposure using DARCA on a modality already equipped with dose‐reducing technology. Additionally, we assessed applicability of 1 dose area product to effective dose conversion factor for both DARCA and conventional coronary angiography (CCA) procedures.

Methods and Results

Twenty patients were examined using DARCA and were compared with 20 age‐, sex‐, and body mass index–matched patients selected from a prior study using CCA on the same x‐ray modality. All irradiation events are simulated using PCXMC (STUK, Finland) to determine organ and effective doses. Moreover, for DARCA each frame is simulated. Staff dose is measured using active personal dosimeters (DoseAware, Philips Healthcare, The Netherlands). With DARCA, median cumulative dose area product is reduced by 57% (ie, 7.41 versus 17.19 Gy·cm²). Effective dose conversion factors of CCA and DARCA are slightly different, yet this difference is not statistically significant. The occupational dose at physician's chest, leg, and collar level are reduced by 60%, 56%, and 16%, respectively, of which the first 2 reached statistical significance. Median effective dose is reduced from 4.75 mSv in CCA to 2.22 mSv in DARCA procedures, where the latter is further reduced to 1.79 mSv when excluding ventriculography.

Conclusions

During invasive coronary angiography, DARCA reduces radiation exposure even further toward low‐dose values on a system already equipped with advanced image processing and noise reduction algorithms. For both DARCA and CCA procedures, using 1 effective dose conversion factor of 0.30 mSv·Gy⁻¹·cm⁻² is feasible.

Is Dual-Axis Rotational Coronary Angiography Radiation Dose Reduction Achievable in a Population with 100% Suspected Coronary Artery Disease? A Randomized Trial

BACKGROUND

Previous studies have shown a reduction in radiation dose and contrast volume using dual-axis rotational coronary angiography (DARCA), but this has not been replicated in a population with 100% coronary artery disease (CAD).

OBJECTIVE

To find if DARCA dose reduction is achievable in this population, we sought to compare the radiation dose, contrast volume, and procedure time between DARCA and conventional coronary angiography (CCA) techniques in a setting characterized by a prevalence of 100% suspected coronary artery disease.

METHODS

An all-comer, prospective, randomized, open-label trial was conducted. Cine acquisition dose-area product (DAP), cumulative air kerma (AK), effective dose (E), fluoroscopic time, contrast volume, AK, cine acquisition DAP (CADAP), fluoroscopic DAP (F-DAP), and total DAP were compared between DARCA and CCA groups.

RESULTS

We included 503 consecutive patients with suspected CAD. 252 were assigned to DARCA and 251 to CCA. Stable coronary artery disease was reported in 465 cases and non-ST elevation acute coronary syndrome in 38. Mean age: 61.88 ± 11.2 years, male gender 70.2%. DARCA arm patients showed lower total E dose (6.85 [4.55-10.83] vs. 7.91 [5.58-11.94] Sv; P = .0023), and cine E (3.00 [2.00-4.00] vs. 4.00 [3.00-5.00] Sv; P < .0001). Total DAP was also lower (40.3 [26.8-63.7] vs. 46.5 [32.8-70.2] Gycm²; P = .0023), as a consequence of a lower CADAP (16.3 [10.5-22.9] vs. 23.4 [17.4-32.0] Gycm²; P < .0001), with lower AK (367 [248-1497] vs. 497 [381-1827] mGy; P < .0001), with less contrast medium used (90 [60.0-106.0] vs. 100 [75.0-120.0] mL; P = .014).

CONCLUSION

In a population with 100% suspected coronary artery disease, DARCA provides accurate information required in CAD, is safe, and results in a significant decrease in contrast material volume and radiation dose compared with CCA. The required extra projections did not neutralize the DARCA radiation dose and contrast volume reduction achievements.

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.

Bi-plane and single plane angiography: a study to compare contrast usage and radiation doses for adult cardiac patients in diagnostic studies

OBJECTIVE:

This study compares the performance of bi-plane coronary angiography against single plane angiography in terms of the volume of contrast used (ml) and the total dose-area product (DAP) (μGym²) to the patient measured directly via flat panel detectors.

METHODS:

A total of 5176 adult diagnostic cardiac angiograms from a hospital in Brisbane, Australia were retrospectively studied. Patients with aortograms, iliac or femoral artery imaging, and stenting or graft interventions were excluded. Student's t-tests were used to compare means, and confounding variables were compared using multivariate regression. This quantified the effects of bi-plane system use holding constant other factors (e.g.) body mass index (BMI), age, room, sex, number of digital acquisitions and fluoro time.

RESULTS:

Bi-plane imaging had an average difference in mean contrast use of -15.1 ml [15.5% 95% confidence interval (CI) (-13.2, -17.0) p<0.001], multivariate regression demonstrated a -27.0 ml reduction in contrast use [28% 95% CI (-29.0, -24.83) p<0.0001] when the significant effects of fluoro time, number of digital acquisitions, BMI and sex were held constant. Bi-plane imaging had an average difference in mean DAP of + 887.1 μGym² [23% 95% CI (+1110.7, +663.4) p < 0.001], whilst multivariate regression found a +628.3 Gym² increase in DAP [16% 95% CI (+467.5, +789.3) p<0.001] when the significant effects of fluoro time, number of digital acquisitions, BMI and sex were held constant.

CONCLUSION:

These results demonstrate that bi-plane imaging uses less contrast media than single-plane imaging for coronary angiography at the expense of more radiation. Bi-plane imaging may be preferable in patients with renal impairment, however single plane imaging may be preferable in those without renal impairment.

ADVANCES IN KNOWLEDGE:

This is a large cohort and statistically comprehensive study comparing bi-plane and single plane coronary angiography. Other studies 4, 5, 6, 12 have used Student's t-tests to measure the difference between means, however this provides no causative information on the differences found. This study provides a view of the causative impact of bi-plane usage on DAP and contrast use via multivariate regression modelling.

Impact of single-plane versus Bi-plane imaging on procedural time, fluorescence time, and contrast medium volume in retrograde chronic total occlusion percutaneous coronary intervention

OBJECTIVE

The aim of the study is to evaluate the impact of single-plane and bi-plane imaging on procedural time, fluorescence time, and contrast medium volume in retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

METHODS

Between January 2008 and December 2015, a total of 359 patients received scheduled retrograde CTO PCI and were enrolled in the study; 119 patients underwent PCI by single-plane imaging, and another 240 patients underwent PCI by bi-plane imaging.

RESULTS

A 95.0% rate of technical success was noted in the single-plane imaging group, and a 95.8% rate of technical success was noted in the bi-plane imaging group. All patients received the CTO approach via the retrograde method, and the retrograde method success rate was 88.2% in single-plane imaging group, and 81.7% in the bi-plane imaging group. A longer procedural time (153.73 ± 53.15 vs 172.88 ± 61.30 min; P = 0.004), longer fluorescence time (71.40 ± 25.96 vs 80.95 ± 34.70 min; P = 0.008), and more contrast medium volume (342.77 ± 102.25 vs 394.58 ± 156.41 mL; P = 0.001) were noted in the bi-plane imaging group. After propensity score match, a longer procedural time, longer fluorescence time, and more contrast volume was noted in bi-plane group.

CONCLUSION

Bi-plane imaging could not decrease procedural time, fluorescence time, and contrast medium volume in retrograde CTO PCI.

WASP - Write a Scientific Paper course: why and how

The ability to write up research in the form of a paper is a crucial requisite for academics. The skills required are manifold and are acquired piecemeal during an individual's training. Matters would be facilitated by a short and intensive course that would cover all of these facets. Such a course would ideally be delivered by experienced writers and editors. It is for this very reason that WASP (Write a Scientific Paper) was created. WASP was held outside of Malta for the first time, in London. This paper describes the preparations required in order to plan and execute a course of this or similar nature.

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.

Dual-Axis Rotational Angiography is Safe and Feasible to Detect Coronary Allograft Vasculopathy in Pediatric Heart Transplant Patients: A Single-Center Experience

Coronary allograft vasculopathy (CAV) is the leading cause of graft failure in pediatric heart transplant recipients, also adding to mortality in this patient population. Coronary angiography is routinely performed to screen for CAV, with conventional single-plane or bi-plane angiography being utilized. Dual-axis rotational coronary angiography (RA) has been described, mostly in the adult population, and may offer reduction in radiation dose and contrast volume. Experience with this in the pediatric population is limited. This study describes a single-institution experience with RA for screening for CAV in pediatric patients. The catheterization database at our institution was used to identify pediatric heart transplant recipients having undergone RA to screen for CAV. Procedural data including radiation dose, fluoroscopy time, contrast volume, and procedure time were collected for each catheterization. The number of instances in which RA was not successful, ECG changes were present, and CAV was detected were also collected for each catheterization. A total of 97 patients underwent 345 catheterizations utilizing RA. Median radiation dose-area product per kilogram was found to be 341.7 (mGy cm(2)/kg), total air kerma was 126.8 (mGy), procedure time was 69 min, fluoroscopy time was 9.9 min, and contrast volume was 13 ml. A total of 17 (2 %) coronary artery injections out of 690 could not be successfully imaged using RA. A total of 14 patients had CAV noted at any point, 10 of whom had progressive CAV. Electrocardiographic changes were documented in a total of 10 (3 %) RA catheterizations. Procedural characteristics did not differ between serial catheterizations. RA is safe and feasible for CAV screening in pediatric heart transplant recipients while offering coronary imaging in multiple planes compared to conventional angiography.

Comparison of Contrast Volume, Radiation Dose, Fluoroscopy Time, and Procedure Time in Previously Published Studies of Rotational Versus Conventional Coronary Angiography

Conventional coronary angiography (CA) with static imaging is limited by the ability to properly select the optimal acquisition angle, vessel foreshortening, and significant radiation exposure. Rotational coronary angiography (RA) acquires coronary images in a multitude of viewing angles during a single injection by means of a moving gantry that rapidly completes a predefined arc. This study compares procedural characteristics of CA and RA. Electronic search of databases such as OVID, Medline, and PubMed was conducted to identify studies comparing procedural characteristics of CA and RA. End points for analysis included contrast volume, radiation dose by dose area product, radiation dose by air kerma, fluoroscopy time, and procedure time. Studies were assessed for quality and bias and were included if they compared coronary imaging of both the right and left coronary systems with CA and RA, included one of the end points of interest, and were in English. A total of 11 studies consisting of 940 patients who underwent RA and 976 who underwent CA were included in the final analysis. Contrast volume, radiation dose by dose area product, and radiation dose by air kerma were all found to be significantly lower with RA compared with CA. There was a statistically significant increase in fluoroscopy time, although this was not clinically significant, and there was no difference in procedure time. RA angiography is a feasible alternative to CA and offers reductions in contrast used and radiation exposure.

A comparison of radiation dose between standard and 3D angiography in congenital heart disease

Background

The use of three-dimensional rotational angiography (3D-RA) to assess patients with congenital heart diseases appears to be a promising technique despite the scarce literature available.

Objectives

The objective of this study was to describe our initial experience with 3D-RA and to compare its radiation dose to that of standard two-dimensional angiography (2D-SA).

Methods

Between September 2011 and April 2012, 18 patients underwent simultaneous 3D-RA and 2D-SA during diagnostic cardiac catheterization. Radiation dose was assessed using the dose-area-product (DAP).

Results

The median patient age and weight were 12.5 years and 47.5 Kg, respectively. The median DAP of each 3D-RA acquisition was 1093µGy.m² and 190µGy.m² for each 2D-SA acquisition (p<0.01). In patients weighing more than 45Kg (n=7), this difference was attenuated but still significant (1525 µGy.m² vs.413µGy.m², p=0.01). No difference was found between one 3D-RA and three 2D-SA (1525µGy.m² vs.1238 µGy.m², p = 0.575) in this population. This difference was significantly higher in patients weighing less than 45Kg (n=9) (713µGy.m² vs.81µGy.m², P = 0.008), even when comparing one 3D-RA with three 2D-SA (242µGy.m², respectively, p<0.008). 3D-RA was extremely useful for the assessment of conduits of univentricular hearts, tortuous branches of the pulmonary artery, and aorta relative to 2D-SA acquisitions.

Conclusions

The radiation dose of 3D-RA used in our institution was higher than those previously reported in the literature and this difference was more evident in children. This type of assessment is of paramount importance when starting to perform 3D-RA.

Reconstruction of coronary trees from 3DRA using a 3D+t statistical cardiac prior

A 3D+t description of the coronary tree is important for diagnosis of coronary artery disease and therapy planning. In this paper, we propose a method for finding 3D+t points on coronary artery tree given tracked 2D+t point locations in X-ray rotational angiography images. In order to cope with the ill-posedness of the problem, we use a bilinear model of ventricle as a spatio-temporal constraint on the nonrigid structure of the coronary artery. Based on an energy minimization formulation, we estimate i) bilinear model parameters, ii) global rigid transformation between model and X-ray coordinate systems, and iii) correspondences between 2D coronary artery points on X-ray images and 3D points on bilinear model. We validated the algorithm using a software coronary artery phantom.

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.

Benefits of dual-axis rotational coronary angiography in routine clinical practice

Dual-axis rotational coronary angiography (DARCA) is a new imaging technique involving three-dimensional rotation of the gantry around the patient with simultaneous left to right and craniocaudal movements. This allows complete imaging of the left or right coronary tree with a single acquisition run. Previous small studies have indicated that DARCA is associated with reduced radiation dose and contrast use in comparison with standard coronary angiography (SCA). We conducted a registry of unselected patients undergoing DARCA or SCA. DARCA was used in 107 patients and SCA in 105 patients. Mean number of acquisition runs was 2.6 for DARCA and 6.9 for SCA (P < 0.0001). Mean radiation dose (dose-area product, DAP) was 30.4 Gy cm(2) for SCA and 15.9 Gy cm(2) for DARCA (P < 0.0001). Mean contrast volume was 41.7 ml for SCA and 25.7 ml for DARCA (P < 0.0001). Case time for DARCA in the first half of the study was 20.8 ± 1.4 min compared with 15.2 ± 2.0 min in the second half of the study (P = 0.0015), suggesting a learning curve. In the DARCA group, 64 % of patients required only two acquisition runs for complete and satisfactory imaging. There were no adverse effects resulting from DARCA. Two cases are presented to illustrate the diagnostic ability of DARCA. DARCA was associated with a 48 % reduction in radiation dose and 36 % reduction in contrast volume in comparison with SCA, with comparable diagnostic ability.