Planar Angiography Research Articles

Comparative analysis of single plane and biplane angiography systems for mechanical thrombectomy for acute ischemic stroke: a systematic review and meta-analysis

BackgroundThe choice of angiography system could influence the outcomes of mechanical thrombectomy (MT) in the treatment of acute ischemic stroke (AIS), but its impact is not yet well understood. This...

Safety and Effectiveness of Mechanical Thrombectomy for Acute Ischemic Stroke Using Single Plane Angiography

ObjectivesNearly all data on mechanical thrombectomy for acute ischemic stroke is based on procedures performed on biplane angiography systems. However, thrombectomy may be performed on single-plane systems in situations of triage or limited resources. We present the first US study comparing the safety and effectiveness of mechanical thrombectomy performed on single-plane vs. biplane systems. Methods and MethodsA retrospective review of a prospectively maintained database identified all patients treated with thrombectomy between July 2020 and July 2021 by a high-volume practice. Patients were dichotomized into those treated on single plane and biplane systems. Demographic, procedural, clinical and follow-up characteristics were compared. ResultsOf the 246 patients treated with mechanical thrombectomy, 70 (33%) and 141 (66%) patients were treated on SP and BP systems, respectively. No significant differences were detected in follow-up ‘good functional outcome’ (mRS ≤ 2; SP 51% vs BP 43%, p = 0.14), successful recanalization (SP 87% vs BP 88%, p = 0.72), intra-procedural vascular injury (SP 3% vs BP 2%, p = 0.96), or time from groin puncture to reperfusion (SP 24 min vs BP 26 min, p = 0.58). Additionally, no significant differences were detected in peri-procedural complications, fluoroscopy times or total radiation. Patients treated on single plane systems required significantly more contrast. ConclusionsMechanical thrombectomy for acute ischemic stroke performed on single plane angiography systems is as safe and efficacious as when performed on biplane systems. Our results may have implications for increasing stroke care access, both domestically in underserved/rural areas and internationally when considering requirements for stroke care in lower-income countries.

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

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. 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. 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. 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. 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.

3:09 PM Abstract No. 182 Comparison of cone-beam CT versus computed tomography intraarterial angiography for intraprocedural TACE planning

To compare imaging characteristics of intraarterial cone-beam computed-tomography angiography (CBCTA) versus computed tomography angiography (IACTA) for transarterial chemoembolization (TACE) planning. This single-institution retrospective study included 144 patients submitted to 181 TACE sessions under conscious sedation (CBCTA, n = 111; IACTA, n = 70) from January 2015 to July 2017. CBCTA was performed using a single plane angiography system equipped with a 30×40 cm flat detector (Syngo 6s DR DynaCT, Artis Zee, Siemens, Germany). IACTA was performed using a hybrid Angio-CT system equipped with a 128-slice sliding gantry CT (MIYABI Angio CT, Siemens, Germany). Similar intraarterial contrast injection protocols were utilized for both modalities. Multi-planar reformatted CBCTA- and IACTA-images (5-10 mm MPR MIP Thick) were independently reviewed by two readers in a dedicated workstation and classified using a binary (yes vs no) system (breathing motion artifact, and field of view [FOV] coverage of entire liver) or a 3-/4-level ordinal grading system (tumor conspicuity, tumor arterial feeder conspicuity, streaking artifacts, overall vessels conspicuity, and overall image quality). CBCTA and IACTA groups were compared using a F-test and score test. There were no significant differences in patient demographic and tumor characteristics between the IACTA and CBCTA groups. IACTA was significantly superior to CBCTA in respect to better tumor conspicuity (P < 0.01), tumor arterial feeder conspicuity (P = 0.02), less frequent incidence of streaking artifact (P < 0.01), FOV coverage of entire liver (CBTCTA: 22%; IACTA: 84%; P < 0.01), overall vessel conspicuity (P < 0.05), and overall image quality (P < 0.001). CBCTA trended to have more frequent image degradation due to breathing motion during acquisition (CBCTA: 10%; IACTA: 1.4%; P = 0.057). IACTA provides more reliable and consistent imaging information when compared to CBCTA for liver soft-tissue and vessel analysis for intraprocedural TACE planning. Further studies are required to explore the diagnostic utility and radiation dose of IACTA in the context of TACE planning in a hybrid CT angio suite.

Comparative, multidimensional imaging of patent ductus arteriosus and a proposed update to the morphology classification system for dogs.

BackgroundAccurately assessing the morphology and shape of the patent ductus arteriosus (PDA) and obtaining measurements are important to avoid procedural complications.ObjectivesTo characterize and compare PDA morphology, shape, and dimensions with angiography and echocardiography.Animals25 client‐owned dogs with echocardiographically confirmed PDA.MethodsProspective case series. Imaging consisted of single plane angiography, transthoracic echocardiography from the right (TTE‐R) and left (TTE‐L), and two‐dimensional, biplane, and three‐dimensional transesophageal echocardiography (TEE‐2D and TEE‐3D). Measurements included angiographic minimal ductal diameter (MDD), echocardiographic pulmonary ostium in a single dimension (TTE‐R, TTE‐L, and TEE‐2D) and in perpendicular dimensions (TEE‐3D) with similar measurements of the ampulla 3 mm above the MDD or pulmonary ostium. The morphology and shape of the PDA were characterized.ResultsCatheter‐based occlusion (N = 20) and surgical ligation (N = 5) were performed without complication. Angiographic morphology was classified as type II (N = 19), type III (N = 1), and other (N = 1). Angiographic MDD and TEE‐2D pulmonary ostium measurements were significantly (P = .008) but weakly correlated (r = .56); similar relationships were found for ampulla diameter measurements (P < .0001; r = .75). In general, TEE‐2D did not correlate with other imaging modalities measurements. Based on TEE‐3D measurements, the majority of pulmonary ostium (17/24; 71%) and ampulla (19/24; 79%) were oval.Conclusions and Clinical ImportanceMeasurements using different imaging modalities are not interchangeable. TEE‐3D provided an en face view of the PDA that cannot be replicated with other echocardiographic techniques and demonstrated an oval shape in the majority of dogs. We propose an update to the current classification system to include additional PDA morphologies.

Constraining OCT with Knowledge of Device Design Enables High Accuracy Hemodynamic Assessment of Endovascular Implants.

BackgroundStacking cross-sectional intravascular images permits three-dimensional rendering of endovascular implants, yet introduces between-frame uncertainties that limit characterization of device placement and the hemodynamic microenvironment. In a porcine coronary stent model, we demonstrate enhanced OCT reconstruction with preservation of between-frame features through fusion with angiography and a priori knowledge of stent design.Methods and ResultsStrut positions were extracted from sequential OCT frames. Reconstruction with standard interpolation generated discontinuous stent structures. By computationally constraining interpolation to known stent skeletons fitted to 3D ‘clouds’ of OCT-Angio-derived struts, implant anatomy was resolved, accurately rendering features from implant diameter and curvature (n = 1 vessels, r2 = 0.91, 0.90, respectively) to individual strut-wall configurations (average displacement error ~15 μm). This framework facilitated hemodynamic simulation (n = 1 vessel), showing the critical importance of accurate anatomic rendering in characterizing both quantitative and basic qualitative flow patterns. Discontinuities with standard approaches systematically introduced noise and bias, poorly capturing regional flow effects. In contrast, the enhanced method preserved multi-scale (local strut to regional stent) flow interactions, demonstrating the impact of regional contexts in defining the hemodynamic consequence of local deployment errors.ConclusionFusion of planar angiography and knowledge of device design permits enhanced OCT image analysis of in situ tissue-device interactions. Given emerging interests in simulation-derived hemodynamic assessment as surrogate measures of biological risk, such fused modalities offer a new window into patient-specific implant environments.

The fine line between Takayasu arteritis and giant cell arteritis.

The objective of this study is to describe a series of patients above the age of 50 years with large vessel arteritis and vascular involvement typical of TAK. A retrospective review of 18 patients (median age 64 years) with emphasis on clinical characteristics, laboratory values, and vascular involvement by CT, MRI, or planar angiography. Five patients fulfilled the ACR criteria for GCA, five for TAK, three both GCA and TAK, while five patients did not fulfill the criteria for either disease. The dominant presenting symptoms were constitutional, while only a few patients had cranial or peripheral symptoms. Sixty-one percent had physical signs of vascular compromise. Temporal artery biopsy showed giant cell arteritis in six out of nine biopsies. Arterial involvement: 78 % had either involvement of the ascending aorta, the aortic arch, descending or/and abdominal aorta, 9 carotid, 12 subclavian, 5 axillary, 3 renal, 7 iliac, and 2 femoral arteries; 7 mesenteric or celiac trunk. All the patients were treated with prednisone and 50 % with steroid-sparing drug. Nine out of 15 patients (60 %) achieved remission after 1 year of follow-up. No substantial differences in the distribution of vascular involvement, type of treatment, or outcome measures were observed between patients fulfilling criteria for GCA or TAK. Vascular involvement typical of TAK in patients above the age of 50 years with large vessel arteritis seems to be more frequent than previously assumed. Our findings support the assumption that TAK and GCA represent a spectrum of the same disease.

AB0440 The fine line between takayasu and giant cell arteritis: a retrospective study

BackgroundTakayasu arteritis (TAK) and Giant cell arteritis (GCA) are classified as two different vasculitides.[1] The differentiation is based on age at onset (under 40y for TAK, above 50y for GCA)...

Model generation of coronary artery bifurcations from CTA and single plane angiography

To generate accurate and realistic models of coronary artery bifurcations before and after percutaneous coronary intervention (PCI), using information from two image modalities. Because bifurcations are regions where atherosclerotic plaque appears frequently and intervention is more challenging, generation of such realistic models could be of high value to predict the risk of restenosis or thrombosis after stent implantation, and to study geometrical and hemodynamical changes. Two image modalities have been employed to generate the bifurcation models: computer tomography angiography (CTA) to obtain the 3D trajectory of vessels, and 2D conventional coronary angiography (CCA) to obtain radius information of the vessel lumen, due to its better contrast and image resolution. In addition, CCA can be acquired right before and after the intervention in the operation room; therefore, the combination of CTA and CCA allows the generation of realistic preprocedure and postprocedure models of coronary bifurcations. The method proposed is semiautomatic, based on landmarks manually placed on both image modalities. A comparative study of the models obtained with the proposed method with models manually obtained using only CTA, shows more reliable results when both modalities are used together. The authors show that using preprocedure CTA and postprocedure CCA, realistic postprocedure models can be obtained. Analysis carried out of the Murray's law in all patient bifurcations shows the geometric improvement of PCI in our models, better than using manual models from CTA alone. An experiment using a cardiac phantom also shows the feasibility of the proposed method. The authors have shown that fusion of CTA and CCA is feasible for realistic generation of coronary bifurcation models before and after PCI. The method proposed is efficient, and relies on minimal user interaction, and therefore is of high value to study geometric and hemodynamic changes of treated patients.

Ray-based approach to skeletal muscle perfusion measurement on interventional x-ray systems

Periprocedural assessment of tissue perfusion by imaging methods could improve outcome control during treatment of peripheral vascular disease. Currently, endovascular revascularization treatments are assessed by planar angiography which only allows for qualitative inspection of blood flow in vessels. In this paper, we present a method for periprocedural perfusion estimation based on temporal attenuation curves in skeletal muscles using angiographic C-arm systems. The proposed method tackles the loss of spatial depth information which occurs in conventional angiography by combining the acquired angiograms with two additional C-arm rotational soft tissue scans. The area subject to contrast propagation is segmented from the two images that are tomographically reconstructed from the rotational scans and is then used to estimate the spatially averaged temporal contrast attenuation along the x-ray directions from the angiograms. A segmentation method which is tailored to the estimation procedure is applied to limit inaccuracies in the estimation. The accuracy of the method in estimating tissue blood flow in muscular tissue is evaluated in a simulation study using experimental data from CT perfusion acquisitions. Results show that perfusion estimation accuracy is limited owing to spatial inhomogeneity of contrast in muscular tissue and to the presence of vessels along the x-ray directions. Nonetheless, the spatially averaged perfusion quantification allows for improved visual differentiation of normal and hypoperfused tissue in comparison with conventional digital subtraction angiography. Periprocedural assessment of muscle perfusion through digital subtraction angiography is challenging due to lack of longitudinal information in the planar projections. By including additional 3D information on the anatomy retrieved from rotational soft tissue scans, the visualization and differentiation of normal and hypoperfused areas can be improved.

A comparison of patient dose levels between 3/4 vessel conventional angiography and computed tomography angiography during examinations to investigate subarachnoid haemorrhage

The aim of this study was to investigate and compare the levels of ionising radiation dose received by patients whilst undergoing radiological examination for Subarachnoid haemorrhage by conventional angiography (single and bi plane) and computed tomography angiography. The results obtained from previous examinations have been compared to consider which method of investigation delivers the lowest ionising radiation dose to the patient. Consideration was also given to comparing single plane angiography to bi plane angiography as empirical evidence suggested that radiologists received no formal training and only a small amount of informal training on newly installed equipment at the hospital in which the research was carried out. Would this lead to patients being inadvertently exposed to increased radiation as radiologists familiarised themselves with the equipment? The dose received by 30 patients examined for SAH by each modality was converted to effective dose (mSv) for comparison. These results were then further compared by removing the lowest and highest recorded doses to eliminate any bias that may have been caused by skewed data. The results showed that CTA consistently delivered a lower dose to patients than single or bi plane angiography and that bi plane delivered a lower mean average dose than single plane angiography, with or without any skewed data.

Influence of Gravity on Radiographic Contrast Material–Based Measurements of Regional Blood Flow Distribution

Rationale and Objectives Radiographic measurement of regional blood flow distribution in the lungs is potentially biased because the contrast material used to track flow is denser than blood. The authors performed this study to evaluate the effect of gravity on flow estimates by using an experimental test phantom and numeric simulations. Materials and Methods Cross-sectionally uniform boluses of radiopaque contrast material were delivered at the upstream end of a horizontal inlet tube connected to a downstream axisymmetric bifurcation attached to collecting tubing spirals. The phantom was imaged by using both planar angiography and dynamic multi–detector row computed tomography (CT) during the passage of the bolus through the phantom. The images were analyzed to determine the relative amounts of contrast material traveling through the top and bottom branches of the bifurcation by using varying Reynolds numbers and ratios of inlet tube volume to bolus volume. Numeric simulations of flow within a straight channel, with use of a dispersion operator intended to simulate settling of the bolus due to gravity, were performed under conditions representative of those in the experiments. Results When the plane of the bifurcation was vertical and actual flow through the two branches was equal, the fraction of contrast material passing through the downward-directed branch increased with decreasing Reynolds number and increasing inlet tube–bolus volume ratio. This occurred in both the experiments and the simulations. Conclusion Because in the circulation Reynolds number decreases and pathway length increases with decreasing vessel diameter, the accuracy of regional flow measurements obtained with angiography or CT within the lungs may be limited by density differences between contrast material and blood.

Assessment of ejection fraction with Tl-201 gated SPECT in myocardial infarction: Precision in a rest-redistribution study and accuracy versus planar angiography

Background. Viability and left ventricular ejection fraction (LVEF) are essential measures for the assessment of myocardial infarction (MI). These 2 variables may be evaluated simultaneously by means of thallium-201 gated single photon emission computed tomography (SPECT); however, the precision and accuracy of LVEF measurements with this isotope remain controversial, particularly in cases of extended perfusion defects and poor count densities. Methods and Results. Fifty patients with a history of MI underwent a 20-minute rest and a 4-hour redistribution Tl-201 gated SPECT viability protocol, immediately followed by a technetium-99m planar equilibrium radionuclide angiography (ERNA). On gated SPECT images, various count statistics were calculated, and perfusion was automatically quantified by means of CardioMatch, which provided both the size and severity of MI defects. Rest and redistribution LVEFs were determined from gated SPECT with Germano's algorithm, whereas LVEFs were calculated from ERNA using the manufacturer's software. Mean LVEF values calculated with rest gated SPECT, redistribution gated SPECT, and planar ERNA were 30% ± 13%, 30% ± 13% and 33% ± 13%, respectively. Significant differences between repeated gated SPECT LVEFs were not shown by means of the paired t test. Correlation coefficients were high between 20-minute and 4-hour scans (r = 0.89) and between gated SPECT and ERNA (r = 0.88 and r = 0.92 at 20 minutes and 4 hours, respectively). Additionally, close agreement between gated SPECT and ERNA was shown by means of the Bland-Altman plot, despite an underestimation of 3 units. Finally, neither the technical conditions (count density, heart rate, lung uptake, etc) nor the perfusion alteration (size, severity, redistribution) appeared to interfere with the precision and accuracy of gated SPECT LVEF measurement. Conclusion. Tl-201 gated SPECT is a precise method for assessing LVEF within the same patient at 4-hour intervals, even with a substantial count decay, and it gives accurate results compared with planar ERNA, even in the case of large perfusion defects. (J Nucl Cardiol 2001;8:31-9.)

A system for stereotactic radiosurgery with a linear accelerator

A small field irradiation technique to deliver high doses of single fraction photon radiation to small, precisely located volumes (0.5 to 8 cm 3) within the brain has been developed. Our method uses a modified Brown-Roberts-Wells (BRS), CT-guided, stereotactic system and a 6 MV linear accelerator equipped with a special collimator (diameters of 12.5 mm to 30.0 mm projected to isocenter) located 23 cm from isocenter. Target localization via planar angiography has been added. Treatment consists of a series of arcing beams using both gantry and couch rotations. During treatment, the patient's head is immobilized independently of the radiotherapy couch and is precisely positioned without reference to room lasers or light field. A precise verification of alignment precedes each treatment. Extensive performance tests have shown that a target, localized by CT, can be irradiated with a positional accuracy of 2.4 mm in any direction with 95% confidence. If angiography is used for localization, the results are better. The dose 1.0 cm outside the target volume is less than 20% of the prescribed dose for a medium sized collimator.

A semi-quantitative programme for evaluating radio-ventriculograms by a "first passage" technique (author's transl)

Evaluation depends mostly on the demonstration of regional function (muscle movement, regional contraction volume, trend scintigram). A special technique permits the demonstration of insufficiency of the A-V valves and its approximate measurement. Comparison with single plane angiography showed good or excellent agreement concerning the ejection fraction (r = 0.86 for patients in sinus rhythm, 0.92 for patients without valvular disease). Inter observer error is very small (r = 0.99). These studies can be evaluated separately for the right and left ventricles (in an RAO 30 degrees projection).

Left ventricular function and coronary artery anatomy before and after myocardial infarction; a study of six cases.

Six patients underwent cardiac catheterization before and after occurrence of a myocardial infarction. Results from the two procedures allowed the quantitation of changes in coronary artery anatomy and left ventricular performance associated with myocardial infarction. Left ventricular biplane or single plane angiography and selective coronary angiography were used to evaluate coronary artery anatomy, left ventricular end diastolic pressure (LVEDP), left ventricular end diastolic volume (LVEDV), end systolic volume (LVESV), and systolic ejection fraction (SEF) under resting conditions. Four patients had developed occlusion of the artery supplying the area of infarction. In five cases new or progressive contraction abnormalities occurred. One patient had no change in contraction pattern or SEF. Systolic ejection fraction fell in three patients, with no change in LVEDV. In two patients LVEDV rose and SEF fell. These data demonstrate that a wide spectrum of functional abnormalities is associated with myocardial infarction. Infarction was always associated with significant coronary artery stenosis, but not necessarily associated with occlusion. The SEF and contractile pattern were the indicators of left ventricular dysfunction which most frequently deteriorated.