During Digital Subtraction Angiography Research Articles

Abstract 025: CTA carotid web structural characteristics as predictors for contrast stagnation on DSAs

Introduction Carotid webs (CaWs) have been shown to present with a long time of contrast stagnation during digital subtraction angiography (DSA) runs, and this has been proposed as a potential underlying physiopathological feature facilitating thrombosis and stroke. We aim to evaluate the relationship of quantified contrast stagnation with vascular imaging structural characteristics and clinical features of CaW. Methods We retrospectively assessed 48 patients with CaWs who underwent computerized tomography angiography (CTA) and DSA. CaWs’ structural characteristics were evaluated: 1) Length/Base/Thickness: base is the distance between the shoulders of the lesion, while the length is the distance between the midpoint of the base to the web apex. The thickness of the web is the length divided by the base; 2) Angles: we assessed three different web angles: caudal, middle, and cranial angles. All angles are referred to the axis of the vessel. The axis of the carotid is defined as the line spanning a specific length of 15 mm from the exact center of the distal common carotid artery to the center of the internal carotid artery;. The caudal angle is the angle between the line tangent to the caudal wall of the web and the vessel axis. The middle angle is the angle between the length of the web and the vessel axis. The cranial angle is the angle between the line tangent to the cranial wall of the web and the vessel axis. 3) Pocket Area/perimeter: these these measures were calculated by free‐hand delineation of delineating the web rostral surface of the web up to a straight line drawn at 90 degrees from the vessel axis of the carotid artery tangent to the web apex of the web through the vessel posterior wall. The perimeter is the perimeter of the hand‐delimited pocket area; 4) Orientation: it is the CaW ridge in relationship to the horizontal plane based on axial CTA cuts. A region of interest was placed in the DSA post‐web region, the mean Hounsfield units within the ROI was calculated for each frame of the run and a time density curve plotted. CaW structural measurementmeasurements were correlated with the hemodynamic parameters, such as stagnation time and area under the curve (AUC), and the hemodynamic parametersthese were correlated with clinical characteristics. Results Mean age of patients was 52.6 (±10 years), 32 (66.7%) were women, 40 (83.3%) were black, 29 (60.4%) had hypertension, 47 (97.9%) had stroke, from these, 89.4% had a large vessel occlusion. Base size had a weak correlation with AUC (p=0.02) and AUC from peak to 80% clearance (p<0.01). No other correlations were found between CaW structural features (length, thickness, caudal, middle and cranial angles, pocket area and perimeter, and orientation) and hemodynamic parameters (stagnation time, stagnation time from peak to the point of 80% contrast clearance, AUC, and AUC from peak to the point of 80% of contrast clearance). Moreover, there are no correlations between those hemodynamic parameters with admission NIH, systolic or diastolic blood pressure, heart rate, clot burden, ASPECTS, automated CT cerebral perfusion defect volume [Tmax>6 seconds], 90 day NIHSS, and 90 day mRS. Conclusion Base size was correlated with the AUC and AUC from the peak to the 80% clearance. No other hemodynamic parameters were correlated with the clinical characteristics. The relationship between DSA contrast stagnation and clinical outcomes remains unclear.

Improved stereo perception in coronary angiography using the X-ray tube as the viewpoint and validation with 3D printed models

Coronary angiography (CAG) provides two-dimensional images, but a clinician who is experienced in percutaneous coronary interventions can use information from these images to interpret spatial depth and infer the three-dimensional (3D) locations of vessels. We hypothesized that CAG results were equivalent to the mirror image of a coronary artery perspective projection, and a stereo perception could be easily established when the viewpoint of the angiogram was the X-ray tube instead of the detector. To eliminate the influence of heartbeat and respiration, a 3D-printed a coronary artery model was constructed for analysis. The effects of gantry movements during digital subtraction angiography (DSA) on the image were used to identify factors that affected DSA image transformation. Then, based on these factors, DSA imaging was simulated using UG NX software with three methods: (i) a perspective projection with the detector as the viewpoint; (ii) a parallel projection; and (iii) a mirror image of the perspective projection with the X-ray tube as the viewpoint. Finally, the resulting 3D images were compared with the DSA image. Our mirror image of the coronary artery perspective projection that used the X-ray tube as the viewpoint fused precisely with the CAG results and provided exact simulations of all the effects of DSA gantry movements on the DSA image. CAG results were equivalent to the mirror image of coronary artery perspective projection, and the stereo perception was easily established using the X-ray tube as the viewpoint.

Impact of monoplane to biplane angiography upgrade on diagnostic angiography procedures: A retrospective cross-sectional study

The radiation dose during digital subtraction angiography (DSA) examination is determined on the basis of many factors. The aim of this study was to evaluate the dose-area product, air kerma, and fluoroscopy time on monoplane and biplane DSA of the cerebral arteries. Our results show that biplane angiography offered lower DAP, cumulative air kerma at the reference point and fluoroscopy time despite comparable procedure time.. Further research in this area and personnel training warrant the improvement of the radiosafety of angiographic interventional procedures and further development of angiographic technology.

The effect of anaesthetic exposure in presurgical period on delayed cerebral ischaemia and neurological outcome in patients with aneurysmal subarachnoid haemorrhage undergoing clipping of aneurysm: A retrospective analysis.

Background and Aims:Delayed cerebral ischaemia is one of the major contributors to morbidity in aneurysmal subarachnoid haemorrhage (aSAH). General anaesthesia (GA) in the presurgical period may have a preconditioning effect. The primary aim was to assess the effect of preoperative exposure to GA during digital subtraction angiography (DSA) on neurological outcome in patients presenting with aSAH.Methods:After Ethical Committee approval, we conducted a retrospective analysis of the data of patients with aSAH treated surgically. Patients, admitted to neurosurgical ICU (June 2014 and December 2017) with a computed tomography (CT) diagnosis of aSAH and underwent DSA, were included. DSA, done with or without exposure to a general anaesthetic, was classified to GA group and LA group, respectively. Propensity score matching was done on the baseline variables. Appropriate statistical methods were applied.Results:Of the 278 patients, 116 (41.7%) patients had received GA during DSA. Propensity matching yielded 114 (57 in each group) matched patients. In a logistic regression model, the odds ratio (OR) for poor outcome at discharge in GA group as compared to LA group was 4.4 (CI: 2.7–7.4), P = 0.001, whereas, in the matched data, the OR for poor outcome at discharge in GA group as compared to LA group was 1.2 (CI: 0.6–2.6), P = 0.57.Conclusion:The presurgical exposure to GA did not offer any neuroprotection and the odds of poor outcome were higher compare to non-exposure to GA group.

The Effect of Milrinone on the Cerebral Vasospasm in Patients with Subarachnoid Hemorrhage

Introduction: Cerebrovascular diseases are called brain blood vessel problems. The prevalence of brain aneurysms has been reported to be between 6% and 10%. In cerebral aneurysm, vasospasm is known to be the most important curable cause of mortality. Milrinone is used as inotropic drug to dilate vessels via phosphodiesterase inhibition. Therefore, the purpose of this study was to compare the effectiveness of milrinone for treatment of cerebral vasospasm in patients with subarachnoid hemorrhage. Materials and Methods: This is a clinical and double-blind clinical trial performed on all patients with SAH who formed the target population. Furthermore, CT scans and angiography were performed for all patients. 50 I¼g/ml milrinone was injected initially during digital subtraction angiography (DSA) for patients in intervention group, and followed by an infusion of 0.5 to 0.75 I¼g / kg / min. Angiography was repeated 10 minutes after injection. In the control group, the milrinone drug was not injected. Data was analyzed by software spss 20. Descriptive statistics and t-test were used to analyze the parametric data and, the Chi-square test was used for non-parametric masters. Results: The mean age of patients in the two groups did not show a significant difference (P = 0.974). There was no significant difference between the two groups in terms of GCS, at first (P = 0.809). There was a statistically significant difference between the two groups (GCS) after 24 hours and 14 days, respectively (P = 0.004 and P = 0.011), and GCS in the milrinone group improved over 24 hours and 14 days, indicating a positive effect of milrinone on patients with brain aneurysm. A significant difference was found between the two groups in terms of vasospasm treatment (P = 0.033), where the milrinone group showed better improvement of vasospasm. Regarding the overall improvement, the milrinone group had a better treatment when comparing with the control group, but this difference was not found to be statistically significant (P = 0.078). Conclusion: Milrinone was effective in improving vasospasm in patients, but did not improve the patients' neurological status. Furthermore, GCS in the milrinone group was better than the other group after 24 hours and 14 days.

Intra-Arterial Thrombolysis Improves the Prognosis of Acute Ischemic Stroke Patients without Large Vessel Occlusion

Background and Purpose: Intravenous thrombolysis is known as the only effective reperfusion therapy for acute ischemic stroke (AIS) caused by small branches occlusion. However, it is still unclear whether intra-arterial thrombolysis (IAT) is safe and effective for patients without detectable arterial occlusion. This study evaluated the safety and efficacy of IAT in these patients. Methods: Data were collected on consecutive patients from December 2012 to February 2017 at the Xuanwu Hospital, Capital Medical University. AIS patients without large artery occlusion during digital subtraction angiography (DSA) were divided into 2 groups: (1) Intra-arterial urokinase thrombolysis group (UK group): received intra-arterial urokinase thrombolysis treatment; (2) Control group: cerebral angiography examination only. The primary outcome was 3-month favorable functional outcome (modified Rankin Scale 0–2). Results: A total of 48 patients received urokinase thrombolysis, and 34 patients underwent DSA examination only. The UK group had more frequent favorable functional outcomes (70.8 vs. 50%, p = 0.032) at 3-month follow-up and higher score of National Institutes of Health Stroke Scale improvement on the second day (p = 0.007). One patient (2%) had symptomatic intracerebral hemorrhage and 3 patients (6.3%) had asymptomatic intracerebral hemorrhage (asICH) in the UK group. One patient (3.3%) had asICH in the control group. There were no significant differences about ICH. Conclusions: AIS caused by small branches occlusion could benefit from intra-arterial urokinase thrombolysis, and the risk of intracerebral hemorrhage was not significantly higher.

Incidence and risk factors for rebleeding during cerebral angiography for ruptured intracranial aneurysms.

PurposeThe purpose was to evaluate the incidence and risk factors for rebleeding during cerebral angiography in ruptured intracranial aneurysms.Materials and MethodsAmong 1896 patients with ruptured intracranial aneurysms between September 2006 and December 2013, a total of 11 patients who experienced rebleeding of the ruptured aneurysms during digital subtraction angiography (DSA) were recruited in this study.ResultsThere were 184 patients (9.7%) who had suffered rebleeding prior to the securing procedure. Among them, 11 patients experienced rebleeding during DSA and other 173 patients at a time other than DSA. Eight (72.7%) of the 11 patients experienced rebleeding during three-dimensional rotational angiography (3DRA). The incidence of rebleeding during DSA was 0.6% in patients with ruptured intracranial aneurysms. Multivariate logistic regression analysis showed that aneurysm location in anterior circulation [odds ratio=14.286; 95% confidence interval (CI), 1.877 to 250.0; p=0.048] and higher aspect ratio (odds ratio=3.040; 95% CI, 1.896 to 10.309; p=0.041) remained independent risk factors for rebleeding during DSA.ConclusionRuptured aneurysms located in anterior circulation with a high aspect ratio might have the risk of rebleeding during DSA, especially during 3DRA.

Intraarterial Injection of Indocyanine Green for Evaluation of Peripheral Blood Circulation in Patients with Peripheral Arterial Disease

To assess the peripheral blood flow of patients with peripheral arterial disease (PAD) by indocyanine green (ICG) arteriography (ICGA) with intraarterial injection of ICG and evaluate the efficacy of the ICGA tests. This study was undertaken from a retrospective review of patients with PAD who underwent ICGA tests during digital subtraction angiography (DSA) between November 2012 and June 2013. We defined some ICGA parameters as the magnitude of intensity of ICG, the time to maximum intensity, and the time from fluorescence onset to half the maximum intensity (T1/2). The ICGA parameters were evaluated in 2 regions, named regions of interest (ROIs). ROI 1 was part of the dorsum of the foot from the Chopart joint to the Lisfranc joint. ROI 2 was in the distal region of the first metatarsal bone and compared with the ankle-brachial pressure index (ABI), ankle pressure, toe-brachial pressure index, and toe pressure. A total of 22 limbs in 16 patients with PAD underwent ICGA tests during DSA. The T1/2 on ROI 2 was the most correlated with the ABI (ρ=-0.622, P=0.003). A value of T1/2 for ROI 2>10 sec was significantly correlated with an ABI value of <0.7 (sensitivity: 0.85, specificity: 1.0). By measuring the value of T1/2 in ROI 2, ICGA tests can be performed to assess the peripheral blood circulation during DSA. ICGA tests might help to promptly assess the peripheral blood flow during endovascular treatment procedures.

Contrast agent suppresses endothelium-dependent arterial dilation after digital subtraction angiography procedure in patients with diabetic foot

Recent studies showed that contrast agents can induce renal injury. Thus, the present study was designed to assess whether the contrast agents used during digital subtraction angiography (DSA) procedure can damage endothelium. Fow-mediated endothelium-dependent vasodilation (FMD) was measured at baseline, 1, 3, and 7 days after DSA in 198 subjects with diabetic foot. We also measured the levels of thiobarbituric acid-reactive substances (TBARS) and von Willebrand factor (vWF), interleukin (IL)-6, tumor necrosis factor (TNF)-α, and C-reactive protein (CRP). Compared with baseline (3.60 ± 0.47 %), FMD at 1 day decreased (2.74 ± 0.47 %), and increased significantly from 1 to 3 days (p < 0.01), and returned to baseline level at 7 days after DSA. The plasma TBARS increased at 1 day and decreased from 1 to 3 days (p < 0.01), and returned to baseline level at 7 days after DSA. CRP, IL-6, and TNF-α had similar changes before and after DSA procedure. FMD was significantly correlated to vWF, IL-6, TNF-α, CRP, and TBARS (p < 0.01). A negative correlation between contrast volume and FMD, positive correlation between contrast volume and vWF, TBARS, CRP, IL-6 at 1 or 3 days after DSA exist in diabetic group (p < 0.05). Contrast medium suppresses FMD, probably through an increased production of oxygen-derived free radicals and inflammation although adequate hydration was given in type 2 diabetes. Therefore, an effective prophylaxis should allow to prevent this complication.

Step back from the patient: Reduction of radiation dose to the operator by the systematic use of an automatic power injector for contrast media in an interventional angiography suite

During arterial interventional procedures, power injectors allow the operator to step back from the patient or exit the angiography suite during digital subtraction angiography (DSA) acquisitions. Increasing the distance to the radiation source reduces exposure to the operator and staff. To systematically investigate the effect of increasing the distance between the radiation source and the operator during DSA acquisitions in a daily clinical setting, regarding radiation exposure to the operator and patient, as well as the duration of the procedure using a power injector to deliver contrast media. Patients scheduled for arterial interventional procedures in the pelvis or lower extremities were consecutively included. In phase one (duration 6 weeks, 44 patients) contrast media were injected manually. In phase two (duration until the total dose area product [DAP] was equal to phase 1, 41 patients) the operator used a power injector and exited the suite whenever possible. Patient, procedure, and examination data were recorded. Collective dose to the operator's collar, lead apron, and hands was recorded using thermo luminescent dosimetry (TLD). Our results showed a dose reduction of 50% to the operator's hands, lead apron, and thyroid collar when using a power injector during DSA, with no significant increase in DAP or procedure time when performing pelvic procedures. For lower extremity procedures there was a small but significant increase in procedure time and DAP. Pelvic procedures yielded substantially higher DAP than lower extremity procedures during both phases. Utilization of a power injector, thus allowing the operator to step back from the patient, facilitates a radiation dose reduction to the operator of approximately 50% with no significant increase in patient dose or procedure time during pelvic procedures.

DOSE-AREA PRODUCT TO PATIENTS DURING STENT-GRAFT TREATMENT OF THORACIC AND ABDOMINAL AORTIC ANEURYSMS

This article is the first investigation that studies patient doses (air kerma and DAP) during digital subtraction angiography (DSA) for stent-graft treatment of both thoracic (TAAs) and abdominal (AAAs) aortic aneurysms. Fluoroscopy and exposure time, air kerma and dose-area product (DAP) were analyzed from 100 patients. In 41% of the analyzed patients total air kerma was between 1-2 Gy and for 7% exceeded 2 Gy. Median DAP values for fluoroscopy were 87.6 (TAAs) and 142.2 (AAAs) (Gy cm2) and for exposure 364.7 and 238.7 (Gy cm2), respectively. A 10-min prolongation of treatment causes about 83 Gy cm increase of DAP for fluoroscopy and 390 Gy cm for each 1 s of exposure. A good correlation between DAP and examination times was found for both exposure (r = 0.78) and fluoroscopy (r = 0.7). Moreover, sex was found to be a differential factor for DAP: DAP values for females were about 25% lower for both clinical procedures. For this kind of treatment the radiation doses were obtained for patients. Total air kerma in this kind of treatment for TAAs might be high and can even reach 4 Gy.

Improving the image quality of contrast-enhanced MR angiography by automated image registration: A prospective study in peripheral arterial disease of the lower extremities

Objective If a patient has moved during digital subtraction angiography (DSA), manual pixel shift can improve the image quality. This study investigated whether such image registration can also improve the quality of contrast-enhanced magnetic resonance angiography (MRA) in patients with peripheral arterial disease of the lower extremities. Materials and methods 404 leg MRAs of patients likely to have peripheral artery disease were included in this prospective study. The standard non-registered MRAs were compared to automatically linear, affine and warp registered MRAs by four image quality parameters, including the vessel detection probability (VDP) in maximum intensity projection (MIP) images and contrast-to-noise ratios (CNR). The different registration types were compared by analysis of variance. Results All studied image quality parameters showed similar trends. Generally, registration improved the leg MRA quality significantly ( P < 0.05). The 12% of lower legs with a body shift of 1 mm or more showed the highest gain in image quality when using linear registration instead of no registration, with an average VDP gain of 20–49%. Warp registration improved the image quality slightly further. Conclusion Automated image registration can improve the MRA image quality especially in the lower legs, which is comparable to the effect of pixel shift in DSA.

Characteristics and the Fate of Intraluminal Thrombus of the Intracranial and Extracranial Cerebral Arteries in Acute Ischemic Stroke Patients

Background: The characteristics and fate of intraluminal thrombus (IT), which may incidentally be detected in acute stroke patients, are not well known and the optimal treatment strategy for IT remains controversial. Methods: We have identified patients with IT in either the extracranial or intracranial artery and followed up on their clinical courses and imaging findings. We categorized it based on its morphology and investigated clinical outcomes and fate of IT in those patients. Results: Among 495 patients with acute ischemic stroke, 9 (1.9%, 8 men, age range of 61–84 years) were identified with IT. Patients with IT could be categorized into three groups: a filling defect (4) during digital subtraction angiography (DSA), a stenosis-mimic lesion on DSA (3), and a mobile mass on carotid duplex (2). All patients had follow-up vascular imaging studies. Complete or partial resolution of IT was seen in 8 patients. Four patients developed transient or minor ischemic symptoms, which were potentially related to IT. Stenosis-mimic lesions and IT adjacent to atherosclerotic plaques appeared to be associated with unstable clinical courses. Conclusions: IT can be categorized according to its morphological features. The outcome may depend on the morphology and location of the IT.

Color Doppler sonography in the study of chronic ischemic nephropathy

In western countries, the risk of cardiovascular disease has increased considerably in recent decades. This trend has been paralleled by an increase in cases of atherosclerotic renal disease, which is related to the improved prognosis of cardiovascular diseases, aging, and the increasing mean age of the general population. It is reasonable to expect that in the near future, there will be a sharp increase in the number of elderly patients with atherosclerotic vascular disease in chronic dialysis programs. The result will be a dramatic rise in the social and economic costs of dialysis that could constitute a true clinical emergency. In this epidemiologic scenario, one of the most important targets of 21st century nephrology will be the early diagnosis of chronic ischemic nephropathy and the development of new and more effective strategies for its treatment. Color Doppler (CD) ultrasonography has displayed high sensitivity, specificity, and positive and negative predictive values in the diagnosis of this disease in selected population, making it an ideal tool for use in screening programs. Eligibility for screening should be based on clinical criteria. For the most part, it will be aimed at adults (especially those who are elderly) with atherosclerotic vascular disease involving multiple districts and chronic kidney disease (CKD), stage 2–3, in the absence of a documented history of renal disease. In these patients, hypertension may be a secondary manifestation or a symptom of the ischemic nephropathy itself. The objectives of sonographic screening should be (1) to identify subjects in the population at risk who are affected by stenosis of the main renal artery (RAS); (2) to identify and characterize patients without RAS who have chronic ischemic nephropathy caused by nephroangiosclerosis and/or atheroembolic disease. The former group will require second-level diagnostic studies or angioplasty with stenting; the latter can be managed conservatively. The most important CD parameters in the workup of suspected RAS are those that are direct signs, i.e., increases in peak systolic velocity (PSV) and diastolic velocity (DV), spectral broadening, and an altered renal:aortic ratio (RAR). Their assessment requires full-length sampling of the renal artery and is associated with greater practical/technical difficulties. Measurement in triplicate of the PSV in the ostial, medial, and hilar segments of both arteries and bilateral measurement of parenchymal resistance indices are usually sufficient to detect the presence of stenosis and refer the patient for second-level studies. Important parameters for estimating the severity of a stenosis include the renal:aortic ratio (>3.5), disappearance of the early systolic peak in segmental vessels, lateralization of the resistance index (ΔRI > 0.05), and the evaluation of the acceleration index (AI) and acceleration time (AT). Second-level imaging studies (CT angiography, MR angiography) are still indispensable for precise definition of the location and extension of the stenosis and the therapeutic approach during digital subtraction angiography (DSA). In the absence of direct or indirect signs of RAS, increases in the intraparenchymal resistance indices (RI > 0.75–0.80; PI > 1.50) associated with systemic atherosclerotic disease are indicative of microcirculatory damage related to nephroangiosclerosis or atheroembolic disease.

Radiation doses to patients from digital subtraction angiography

This investigation determined patient doses during digital subtraction angiography (DSA). Fluoroscopy time, dose-area product (DAP) and entrance surface air kerma (ESAK) were analysed from 263 DSA examinations, classified into seven categories: (1) abdominal aorta, iliac, femoral, popliteal and leg arteries; (2) abdominal aorta and superselective DSA of renal arteries; (3) combination of (1) and (2); (4) superselective DSA of common carotid and vertebral arteries, intracranial branches in face and profile projections; (5) superselective DSA of hepatic, splenic, superior and inferior mesenteric arteries; (6) combination of (1) and (4); and (7) celiac trunk and branches. Median DAP values were 67.7, 92.9, 76.6, 53.6, 105.7, 76.1 and 2.6 Gy cm2, respectively. With the exception of one examination, ESAK values were below 2 Gy: the limit for erythema. Compared with published data, DAP values were within the range reported for (1) and (4), slightly larger for (2) and (5), whereas no references were identified for the remaining three categories.