Three-dimensional Rotational Angiography Research Articles

Intra-procedural three-dimensional rotational angiography in cryoballoon ablation of atrial fibrillation - results from a randomised clinical trial

Abstract Introduction There are a variety of approaches for pre-procedural imaging to facilitate atrial fibrillation (AF) ablation. Intra-procedural three-dimensional rotational angiography (3DRA) is the least employed method and it can be advantageous regarding efficiency and procedural logistics (1). There is an open question whether LA imaging could improve safety and outcomes of cryoballoon (CB) ablation. Purpose The aim of this study is to evaluate possible benefits of 3DRA for procedural success, safety and long-term outcomes of CB ablation. Methods We designed a single-centre unblinded randomised clinical trial and recruited 134 patients (64.2% male, 59.0±11.6 years) with paroxysmal (93.3%) and early-persistent AF. Patients were randomised to no imaging or 3DRA which was performed intra-procedurally after trans-septal puncture. Angiographic images were segmented and overlaid to the fluoroscopy screen to guide the ablation procedure. Patients were scheduled for follow-up visits and twenty-four hour ECG recordings at 3, 6 and 12 months, and every 6 months thereafter. Results Of all the patients recruited, 66 (49.3%) were randomised to 3DRA and angiography was successfully performed in all but one patient (1.5%). Procedure time was significantly longer when 3DRA was performed (86.7±27.8 min compared to 67.2±22.1 in non-3DRA group, p<0.001). Total radiation dose (447.4±485.0 vs. 133.9±166.2 mGy, p<0.001) and contrast administration (131.8±28.3 vs. 40.8±26.5 ml, p<0.001) were significantly higher in the 3DRA group (Table 1). In patients who received no imaging one pulmonary vein (PV) couldn’t be isolated in 2 patients while this occurred in 3 patients in the 3DRA group (OR 1.57, 95% CI 0.25-9.72). Only minor complications were reported in both groups. Five patients developed large haematoma (4 in the 3DRA group vs. 1 in the control group). In each group there were 3 incidents of impending or transient phrenic nerve palsy. During 12 months of follow-up, 88.2% of patients in the control group and 81.8% in the 3DRA group were free of atrial fibrillation (OR 1.67, 95% CI 0.63-4.38). Two patients from the control group developed atrial flutter and were treated by ablation. In total, 10 patients underwent redo procedures (7 in the control and 3 in the 3DRA group respectively) and PV reconnections were detected in 9 cases. Conclusion 3DRA is a safe and efficient intra-procedural imaging method to guide CB ablation of AF. However, it significantly increases procedure duration, total radiation dose and contrast expenditure. In our trial it did not have any impact on the acute success rate of PV isolation or freedom from atrial fibrillation during 12-month follow-up.

Three-Dimensional Rotational Angiography as Guidance for Percutaneous Patent Ductus Arteriosus (PDA) Device Closure: A Case Report

Background: Patent Ductus Arteriosus (PDA) is a prevalent congenital heart defect characterized by the persistence of an open arterial connection between the aorta and the pulmonary. Percutaneous PDA closure involves deploying occlusion devices through catheter- based procedures. Case Presentation: We report a 1-year and 6-month-old girl diagnosed with Patent Ductus Arteriosus, presented with persistent complaints of failed to thrive , shortness of breath and recurrent cough. Physical examination revealed a continuous murmur at the upper left sternal border, and the Echocardiography examination confirmed a PDA with size of 4-7 mm, with diastolic shortening and dilatation of the Main Pulmonary Artery (MPA). The successful percutaneous PDA device closure procedure was performed using Three-Dimensional Rotational Angiography (3DRA), following an attempt with Two-Dimensional Angiography, which failed to determine the actual defect size in the patient. Conclusions: Confirming the morphology and size of a PDA can be difficult due to its location between the aorta and pulmonary blood vessels, making it a challenging congenital anomaly to assess accurately. 3DRA precisely delineates the PDA structure located between the aortic and pulmonary blood vessels and acts as a guidance tool for percutaneous PDA device closure.

Modification of Woven Endo-Bridge After Intracranial Aneurysm Treatment: A Methodology for Three-Dimensional Analysis of Shape and Relative Position Changes.

During follow-up of patients treated with WEB devices, shape changes have been observed. The quantitative three-dimensional measurement of the WEB shape modification (WSM) would offer useful information to be studied in association with the anatomical results and try to better understand mechanisms implicated in this modification phenomenon. We present a methodology to quantify the morphology and position of the WEB device in relation to the vascular anatomy. Three-dimensional rotational angiography (3DRA) images of seven aneurysms patients treated with WEBs were used, which also accompanied by a post-treatment 3DRA image and a follow-up 3DRA image. The device was manually segmented, obtaining the 3D models after treatment and at the follow-up. Volume, surface area, height, maximum diameter and WSM ratio of both surfaces were calculated. Position changes were evaluated measuring WEB axis and relative position between post-treatment and follow-up. Changes in WEB volume and surface area were observed with a mean modification of and , respectively. The positional variables also showed differences, mean change of device axis direction was and mean change of distance was . Inter-observer and intra-observer variability analyses did not show differences (ANOVA ). This methodology allows quantifying the morphological and position changes suffered by the WEB device after treatment, offering new information to be studied in relation to the occurrence of WEB shape modification.

Ophthalmic artery stenosis on three-dimensional rotational angiography: Interrater agreement, prevalence, and risk factors.

There is emerging interest in ophthalmic artery (OA) stenosis angioplasty for the treatment of age-related macular degeneration. Three-dimensional rotational angiography (3DRA) could be used during conventional angiography to determine the presence and severity of OA stenosis. In patients who had undergone 3DRA of the internal carotid artery, we aimed to assess the interrater agreement, prevalence, and risk factors for OA stenosis. Consecutive patients from two centers who had undergone conventional angiography with 3DRA of the internal carotid arteries were enrolled in this study. 3DRAs were independently double read for the presence of OA stenosis, as defined as narrowing of the proximal OA of at least 50% when compared to the more distal "normal" OA. Interrater agreement for the evaluation of OA stenosis was assessed with the Cohen's kappa coefficient. Univariate and multivariable logistic regression were used to identify potential predictors of OA stenosis. Three hundred and two patients (97 men; mean ± SD 57.6 ± 13.4 years) were included in the analysis. Cohen's kappa coefficient (95% CI) was 0.877 (0.798-0.956). OA stenosis was present in 45 patients (14.9%). Multiple logistic regression demonstrated that female sex (odds ratio [OR] = 2.70, 95% confidence interval [CI] 1.18-6.09, p = 0.02) and smoking (OR = 2.11, 95% CI 1.10-4.06, p = 0.03) were significant risk factors for OA stenosis. Age, hypertension, diabetes, coronary artery disease, and subarachnoid hemorrhage were not associated with OA stenosis. The evaluation of OA stenosis on 3DRA had excellent interrater agreement. OA stenosis was common and was associated with smoking and female sex.

Giant aneurysm of the middle cerebral artery treated by effective embolization

Giant aneurysms (GA) of middle cerebral artery (MCA) are rare and account for approximately 0.5-4.8% of intracranial artery aneurysms. Early diagnosis of brain GA is critical. Classic digital subtraction angiography (DSA) with the option of three-dimensional rotational angiography remains the “gold standard” in the diagnosis of intracranial aneurysms, including GA. The primary goal of brain GA treatment is to permanently exclude the aneurysm from the circulation while preserving the flow in the candelabra. The secondary goal is to stop the growth of the aneurysm and reduce the ‘mass effect’ symptoms it causes. Despite new endovascular techniques and advances in microsurgery, the treatment of GA MCA is still a therapeutic challenge. There are only a few reports in the literature describing cases of patients diagnosed with GAs of MCA and evaluating various treatment methods. In this article, we present the case of a 78-year-old patient with GA of the right MCA, who underwent effective embolization of the active part of the aneurysm.

Radiological evaluation of middle meningeal artery by 3D rotational angiography.

This study aimed to evaluate the topographic features and branches of the middle meningeal artery (MMA) by three-dimensional rotational angiography (3DRA) and describe its variations' radiological classification based on previous clinical examples of cadaver studies and literature. We consecutively evaluated 87 cerebral hemispheres, including 32 females and 49 right sides between May 2020 and December 2021 who had undergone unilateral or bilateral cerebral and carotid artery 3D rotational angiography imaging by CCA injection and between 18 and 76-years-old. Maximum intensity projection images with 10-30 mm slice thickness were used for the morphological evaluations and measurements of MMA and its foramen, canal, and branches. The diameters of the common carotid artery, internal carotid artery, and external carotid artery were significantly smaller in females than in men (p = 0.021, 0.021, and <0.001, respectively). According to the branching pattern, the most common pattern of the MMA was Type Ia (49.4%). The ophthalmic artery completely originated from MMA in the 1 (1.1%) cerebral hemisphere. The MMA arises from the ophthalmic artery in 2 cerebral hemispheres (2.3%), and the ophthalmic artery and maxillary artery in 2 cerebral hemispheres (2.3%). It was observed that the branching pattern may show differences when compared to the cadaver studies with a radiologic evaluation with 3D-RA.

Transvenous embolization for an intraosseous clival arteriovenous fistula via a proper access route guiding a three-dimensional fusion image: illustrative case.

Intraosseous clival arteriovenous fistulas (AVFs), in which the shunt drains extracranially from the posterior and anterior condylar veins rather than from the cavernous sinus (CS), are rare. Targeting embolization of an intraosseous clival AVF is challenging because of its complex venous and skull base anatomy; therefore, a therapeutic strategy based on detailed preoperative radiological findings is required to achieve a favorable outcome. Here, the authors report the successful targeted embolization of an intraosseous clival AVF using an ingenious access route. A 74-year-old woman presented with left-sided visual impairment, oculomotor nerve palsy, and right facial pain. A fusion image of three-dimensional rotational angiography and cone-beam computed tomography revealed a left CS dural AVF and a right intraosseous clival AVF. The shunt flow of the clival AVF drained extracranially from the posterior and anterior condylar veins via the intraosseous venous route. Transvenous embolization was performed by devising suboccipital, posterior condylar, and intraosseous access routes. The symptoms resolved after the bilateral AVFs were treated. Accurate diagnosis and proper transvenous access based on detailed intraosseous and craniocervical venous information obtained from advanced imaging modalities are key to resolving intraosseous clival AVF.

Three-Dimensional Morphometric Analysis of Anterior Cerebral Circulation Aneurysms.

This article assesses the association between anterior circulation morphometry and the presence of intracranial aneurysm using three-dimensional rotational angiography (3DRA). A retrospective analysis at a Peruvian academic medical center between December 2018 and February 2020 identified 206 patients with unruptured intracranial aneurysms and matched controls who underwent 3DRA. Angiographic images were obtained per standard of care, and measurements of the vasculature were performed using 3DRA vascular automated software. A total of 163 aneurysms and 43 control angiograms were evaluated. Women represented 82.5% of the cases and the mean age was 55.9 years (standard deviation ± 14.2). In multivariate analysis, five specific features were found to be statistically significant predictors for presence of an anterior circulation aneurysm: female sex (odds ratio [OR] = 2.71; p = 0.048), C-shape of the middle cerebral artery (MCA) (OR = 2.73; p = 0.018), distal internal carotid artery (ICA) diameter (OR = 3.42; p = 0.012), ICA bifurcation angle (OR = 1.02; p = 0.036), and length of the carotid siphon (OR = 1.08; p = 0.047). Features detected on 3DRA suggest morphological characteristics of the ICA and MCA may be predictive for intracranial aneurysm. Our findings build from prior reports by demonstrating five specific patient and imaging features associated with anterior circulation aneurysms. While 3DRA is the standard of care in many settings, medical centers with resource limitations may not have access to this technique. The demographic and morphological features identified in our study may have correlates that if detected on contrast computed tomography or magnetic resonance imaging studies, may be used to help screen for a higher level of care in select patients.

Towards developing a segmentation method for cerebral aneurysm using a statistical multiresolution approach

The computer aided diagnosis (CAD) algorithms are considered crucial during the treatment planning of cerebral aneurysms (CA), where segmentation is the first and foremost step. This paper presents a segmentation algorithm in two-dimensional domain combining a multiresolution and a statistical approach. Precisely, Contourlet transform (CT) extracts the image features, while Hidden Markov Random Field with Expectation Maximization (HMRF-EM) segments the image, based on the spatial contextual constraints. The proposed algorithm is tested on Three-Dimensional Rotational Angiography (3DRA) datasets; the average values of accuracy, DSC, FPR, FNR, specificity, and sensitivity, are found to be 99.64%, 92.44%, 0.09%, 5.81%, 99.84%, and 93.22%, respectively. Both qualitative and quantitative results obtained show the potential of the proposed method.

Usefulness of novel fusion imaging with zero TE sequence and contrast-enhanced T1WI for cavernous sinus dural arteriovenous fistula

Evaluation of access routes and shunting points plays a crucial role in the treatment of cavernous sinus dural arteriovenous fistulas (CS-dAVF). Generally, these evaluations are performed using three-dimensional rotation angiography. However, assessing access routes becomes challenging in cases lacking anterior or posterior drainage routes. Zero TE magnetic resonance imaging (MRI) is an innovative technique enabling the visualization of cortical bone. By merging fusion images of zero TE and contrast-enhanced T1 weighted imaging (CE-T1WI), enhanced arteries can be visualized, resembling cranial bone-like three-dimensional rotation angiography. To determine the usefulness of fusion images in evaluating access routes and shunting points for dural arteriovenous fistulas, a comparison was made between these fusion images and three-dimensional rotation angiography in the same case. This report describes the application of fusion images in evaluating access routes and shunting points.

Detection of the Vesical Arteries Using Three-dimensional Digital Subtraction Angiography Relevant to Intra-arterial Infusion Chemotherapy for Bladder Cancer Using Double-balloon Catheters.

This study aims to assess and measure the origin of the superior vesical artery and its distance from the anterior trunk of the internal iliac artery, to which the anticancer drug is infused via double-balloon-occluded arterial infusion bladder-preserving therapy for locally invasive bladder cancer. The 160 pelvic sides of 80 patients were analyzed. Double-balloon catheters were bilaterally introduced into the contralateral superior gluteal artery via the internal iliac arteries using a bilateral transfemoral approach. The proximal balloon is placed at the internal iliac artery, proximally from superior gluteal artery bifurcation, whereas the distal balloon at the origin of the superior gluteal artery to isolate the anterior trunk of the internal iliac artery discharging to the targeted vesical arteries between the balloons. The side hole between the distal and proximal balloons was adjusted at the origin of the anterior trunk of the internal iliac artery to allow clear visualization of the angiographic flow into the bladder. After the distal and proximal balloons were inflated, three-dimensional rotational digital subtraction angiography was performed by simultaneous contrast injection from one extension tube connected to bilateral catheters. The distance (X) between the origins of anterior trunk of the internal iliac artery and superior vesical artery was measured on three-dimensional digital subtraction angiography images, and the origin of the inferior vesical artery was investigated. All superior vesical artery originated from anterior trunk of the internal iliac artery. The mean x was 7.2 mm (range 1.0-22.0 mm). All inferior vesical arterys branched from anterior trunk of the internal iliac artery or its branches. Superior vesical artery commonly originates from the proximal portion of anterior trunk of the internal iliac artery close to superior gluteal artery bifurcation.

Deep learning-based cerebral aneurysm segmentation and morphological analysis with three-dimensional rotational angiography

BackgroundThe morphological assessment of cerebral aneurysms based on cerebral angiography is an essential step when planning strategy and device selection in endovascular treatment, but manual evaluation by human raters only...

Development of a cerebral aneurysm segmentation method to prevent sentinel hemorrhage

Image segmentation being the first step is always crucial for brain aneurysm treatment planning; it is also crucial during the procedure. A robust brain aneurysm segmentation has the potential to prevent the blood leakage, also known as sentinel hemorrhage. Here, we present a method combining a multiresolution and a statistical approach in two dimensional domain to segment cerebral aneurysm in which the Contourlet transform (CT) extracts the image features, while the Hidden Markov Random Field with Expectation Maximization (HMRF-EM) segments the image, based on the spatial contextual constraints. The proposed algorithm is tested on Three-Dimensional Rotational Angiography (3DRA) datasets; the average values of segmentation accuracy, DSC, FPR, FNR, specificity, and sensitivity, are found to be 99.72%, 93.52%, 0.07%, 5.23%, 94.77%, and 99.96%, respectively.

Pure spinal intraosseous arteriovenous fistula: A case report.

Spinal osseous arteriovenous fistula (AVF) is a rare disease with a characteristic angioarchitecture involving an intraosseous venous pouch (VP) of the vertebral body where the feeders are converging. Using spinal angiography alone, it is difficult to distinguish spinal osseous AVF from classical spinal epidural AVF (EDAVF) with fistulas in the epidural VP and bone erosion because both subtypes have an angiographically similar dilated VP appearance. Thus, spinal osseous AVF may be often misdiagnosed as spinal EDAVF. With advancing imaging techniques, it would be possible to determine the exact location of the fistula. Here, we present the case of a 37-year-old woman with a pure spinal thoracic osseous AVF and radiculopathy. She was diagnosed with spinal intraosseous AVF using high-resolution three-dimensional rotational angiography (3D-RA). The fistula was located in the Th1 lateral mass with a VP where multiple osseous feeders were converging. There was paravertebral venous drainage without intradural venous drainage. Transvenous embolization with Onyx and coils was performed through the azygos vein to the lateral epidural venous plexus, resulting in complete obliteration. This case suggests that 3D-RA reconstructed images are essential for accurate diagnosis and successful treatment of this condition. It is important to occlude only intraosseous VPs by accurate subtype diagnosis. Transvenous embolization is a treatment option for spinal intraosseous AVF with paravertebral epidural venous drainage.

Risk factors for the rupture of anterior communicating artery aneurysms: Coexistence of fetal-type posterior cerebral artery and A1 segment hypoplasia/agenesis

PurposeTo investigate the effect of the coexistence of fetal-type posterior communicating artery (fPCA) and anterior cerebral artery (ACA) A1 segment agenesis/hypoplasia on the rupture of an anterior communicating artery (AComA) aneurysm. Materials and MethodsA total of 216 patients consecutively presenting with AComA aneurysms between January 2014 and December 2021 on digital subtraction angiography were evaluated. Patients without three-dimensional rotational angiography images, those aged under 18 years, those with suspected mycotic aneurysms, and those with dissecting and giant aneurysms were excluded from the study. The aneurysms were divided into two groups as ruptured and non-ruptured. Hemodynamic filling patterns were classified into four different types. ResultsThe study included 192 AComA aneurysms, 44.8% (n = 86) ruptured and 55.2% (n = 106) non-ruptured. According to hemodynamic filling patterns, in type 1, the frequency of non-ruptured aneurysms was statistically significantly higher than that of ruptured aneurysms (39.5% vs 18.9%; p = 0.001). In type 4, where fPCA and ACA A1 segment agenesis/hypoplasia coexists, the frequency of ruptured aneurysms was significantly higher than that of non-ruptured aneurysms (10.5% vs 22.7%; p = 0.026). The most common aneurysm size range was 4–7 mm (n = 85; 44.3%). There was no statistically significant difference in size between the ruptured and non-ruptured aneurysms (p = 0.627). ConclusionAccording to the hemodynamic filling classification, we observed that the presence of type 4 filling pattern, i.e., the coexistence of ACA A1 segment agenesis/hypoplasia and fPCA, increased the risk of rupture in AComA aneurysms.

Development of cortical microvascularization in Moyamoya disease using the maximum intensity projection method from three-dimensional rotational angiography.

Neurosurgeons often experience increased cortical microvascularization in Moyamoya disease (MMD). However, there are no previous reports that radiologically evaluated preoperative cortical microvascularization. We investigated the development of cortical microvascularization and clinical characteristics of MMD using the maximum intensity projection (MIP) method. We enrolled 64 patients at our institution, including patients with MMD (n = 26), intracranial atherosclerotic disease (ICAD; n = 18), and unruptured cerebral aneurysms (n = 20) as the control group. All patients underwent three-dimensional rotational angiography (3D-RA). The 3D-RA images were reconstructed using partial MIP images. Cortical microvascularization was defined as the vessels that branched off from the cerebral arteries and were classified as grade 0-2 depending on their development. Cortical microvascularization observed in patients with MMD was classified into grade 0 (n = 4, 8.9%), grade 1 (n = 17, 37.8%), and grade 2 (n = 24, 53.3%). The development of cortical microvascularization was more common in the MMD group than in the other groups. The inter-rater reliability measured using weighted kappa was 0.68 (95% confidence interval = 0.56-0.80). There were no significant differences in cortical microvascularization according to the onset type and hemispheres. Cortical microvascularization correlated with periventricular anastomosis. Most patients with Suzuki classifications 2-5 developed cortical microvascularization. Cortical microvascularization was characteristic of patients with MMD. These findings developed in the early stages of MMD and may act as a bridge to the development of periventricular anastomosis.

Abstract WMP84: Symptomatic Intracranial Atherosclerotic Plaques: Different Morphological Features In The Anterior Versus Posterior Circulation

Introduction: We compared the morphology of intracranial atherosclerotic plaques in the anterior versus posterior circulation, using three-dimensional rotational angiography (3DRA). Methods: We prospectively recruited adult patients with acute ischemic stroke or transient ischemic attack attributed to high-grade (60-99%), atherosclerotic intracranial stenosis as confirmed by 3DRA. We assessed the plaque morphology in 3DRA, including the percentage of luminal stenosis, smooth/irregular/ulcerative plaque surface contour, plaque thickness, length, eccentricity, upstream plaque shoulder angulation, longitudinal distribution of the maximal stenosis, and adjoining branch atheromatous disease (BAD). We compared characteristics of patients with middle cerebral artery-M1 (MCA-M1) and basilar artery (BA) plaques, and the plaque morphology in the two subgroups. Results: Overall, 164 and 17 patients respectively with MCA-M1 and BA plaques were analyzed, with similar age (medians 60 versus 62 years), sex (male 64.6 versus 52.9%) and history of common vascular risk factors. The percentage of luminal stenosis (medians 77 versus 81%), proportion of smooth/irregular/ulcerative plaque surface contour, upstream plaque shoulder angulation (32.1 versus 25.8 °), longitudinal distribution of the maximal stenosis, and presence of adjoining BAD (56.7 versus 64.7%) were similar between MCA-M1 and BA plaques. However, BA plaques were thicker (1.5 versus 1.3mm; p=0.03) and longer (16.4 versus 8.4mm; p&lt;0.001), but less likely eccentric (70.6 versus 88.4%; p=0.039). Conclusions: There were differences in the morphology of symptomatic atherosclerotic plaques in anterior and posterior circulations, independent of demographics and common vascular risk factors. Different artery geometry and the hemodynamics may underlie such differences.

High-throughput 3DRA segmentation of brain vasculature and aneurysms using deep learning

Background and Objectives:Automatic segmentation of the cerebral vasculature and aneurysms facilitates incidental detection of aneurysms. The assessment of aneurysm rupture risk assists with pre-operative treatment planning and enables in-silico investigation of cerebral hemodynamics within and in the vicinity of aneurysms. However, ensuring precise and robust segmentation of cerebral vessels and aneurysms in neuroimaging modalities such as three-dimensional rotational angiography (3DRA) is challenging. The vasculature constitutes a small proportion of the image volume, resulting in a large class imbalance (relative to surrounding brain tissue). Additionally, aneurysms and vessels have similar image/appearance characteristics, making it challenging to distinguish the aneurysm sac from the vessel lumen.Methods:We propose a novel multi-class convolutional neural network to tackle these challenges and facilitate the automatic segmentation of cerebral vessels and aneurysms in 3DRA images. The proposed model is trained and evaluated on an internal multi-center dataset and an external publicly available challenge dataset.Results:On the internal clinical dataset, our method consistently outperformed several state-of-the-art approaches for vessel and aneurysm segmentation, achieving an average Dice score of 0.81 (0.15 higher than nnUNet) and an average surface-to-surface error of 0.20 mm (less than the in-plane resolution (0.35 mm/pixel)) for aneurysm segmentation; and an average Dice score of 0.91 and average surface-to-surface error of 0.25 mm for vessel segmentation. In 223 cases of a clinical dataset, our method accurately segmented 190 aneurysm cases.Conclusions:The proposed approach can help address class imbalance problems and inter-class interference problems in multi-class segmentation. Besides, this method performs consistently on clinical datasets from four different sources and the generated results are qualified for hemodynamic simulation. Code available at https://github.com/cistib/vessel-aneurysm-segmentation.

Reduction of Radiation Dose to Eye Lens in Cerebral 3D Rotational Angiography Using Head Off-Centering by Table Height Adjustment: A Prospective Study.

Three-dimensional rotational angiography (3D-RA) is increasingly used for the evaluation of intracranial aneurysms (IAs); however, radiation exposure to the lens is a concern. We investigated the effect of head off-centering by adjusting table height on the lens dose during 3D-RA and its feasibility in patient examination. The effect of head off-centering during 3D-RA on the lens radiation dose at various table heights was investigated using a RANDO head phantom (Alderson Research Labs). We prospectively enrolled 20 patients (58.0 ± 9.4 years) with IAs who were scheduled to undergo bilateral 3D-RA. In all patients' 3D-RA, the lens dose-reduction protocol involving elevation of the examination table was applied to one internal carotid artery, and the conventional protocol was applied to the other. The lens dose was measured using photoluminescent glass dosimeters (GD-352M, AGC Techno Glass Co., LTD), and radiation dose metrics were compared between the two protocols. Image quality was quantitatively analyzed using source images for image noise, signal-to-noise ratio, and contrast-to-noise ratio. Additionally, three reviewers qualitatively assessed the image quality using a five-point Likert scale. The phantom study showed that the lens dose was reduced by an average of 38% per 1 cm increase in table height. In the patient study, the dose-reduction protocol (elevating the table height by an average of 2.3 cm) led to an 83% reduction in the median dose from 4.65 mGy to 0.79 mGy (P < 0.001). There were no significant differences between dose-reduction and conventional protocols in the kerma area product (7.34 vs. 7.40 Gy·cm², P = 0.892), air kerma (75.7 vs. 75.1 mGy, P = 0.872), and image quality. The lens radiation dose was significantly affected by table height adjustment during 3D-RA. Intentional head off-centering by elevation of the table is a simple and effective way to reduce the lens dose in clinical practice.

Three-dimensional rotational angiography improves mechanical thrombectomy recanalization rate for acute ischaemic stroke due to middle cerebral artery M2 segment occlusions.

Occlusions of the middle cerebral artery (MCA) M2 segments can be difficult to address with mechanical thrombectomy (MTB) using standard projections and this can affect the final recanalization. Three-dimensional rotational angiography (3D-RA) allows to obtain a 3D model of cerebral vessels in a few seconds and to determine the best two-dimensional (2D) projections to be selected to evaluate and treat cerebrovascular diseases, such as aneurysms or vascular malformations. We aimed to determine if 3D-RA could be applied also in MTB. A retrospective review of two patient cohorts treated during two time periods of 12 months before and after the introduction of 3D-RA use at our institution for MTB in M2 occlusions. Analyses were conducted to compare the two groups for procedural characteristics, such as timing, recanalization rate and complications and clinical outcome. One hundred acute ischaemic stroke (AIS) patients (3D-RA group = 57; controls = 43) underwent MTB for an M2 occlusion during the two study periods. Recanalization rates were significantly higher in cases treated with 3D-RA. The mean 3D technique thrombectomy time was compared to that of non-3D cases (47 vs. 49 min, respectively). Our findings showed that 3D-RA is a useful tool to select specific working projections to AIS patients presenting an M2 occlusion by improving final recanalization compared to standard projections, without increasing the overall procedural time.