Rotational Digital Subtraction Angiography Research Articles

RAPID aneurysm accurately measures aneurysm size on CT angiography compared to three-dimensional digital subtraction angiography.

Cerebral aneurysms are often identified and characterized on non-invasive CT Angiography (CTA) images, but digital subtraction angiography (DSA) is the gold standard for aneurysm evaluation. We compared cerebral aneurysm size measurements as measured from CTA processed by a semi-automated artificial intelligence software program (RAPID Aneurysm) and three-dimensional rotational DSA (3D-DSA). We performed a retrospective cohort study of consecutive patients with a cerebral aneurysm who underwent CTA and DSA with 3D reformations. CTA images were processed by RAPID Aneurysm to determine aneurysm height, width, and neck width. The reference standard was aneurysm measurements on 3D-DSA as measured by two neurointerventionalists. Both readers were blinded to RAPID Aneurysm measurements. Correlation and bias between these measurements were determined. Results from 50 patients with 50 aneurysms were compared. 32 patients (64%) were female. Median age was 65 (IQR: 56.25-71.75). 37 patients (74%) presented with ruptured aneurysms. The aneurysms represented a range of aneurysm sizes (1.9-33.3 mm; IQR 3.6-7.2 mm). RAPID Aneurysm size measurements showed excellent correlation and low bias (correlation, mean difference) when compared to the reference standard for aneurysm height (0.98, -0.9 mm), width (0.98, 0.1 mm), and neck width (0.94, 1.1 mm). The inter-reader comparison between the two neurointerventionalists was similarly excellent for aneurysm height (0.97, -0.4 mm), width (0.98, -0.2 mm), and neck width (0.89, 0.8 mm). RAPID Aneurysm measurement of cerebral aneurysm height, width, and neck width on CTA is strongly correlated to expert neurointerventionalist measurements on 3D-DSA.

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.

Funnel Shaped Anterior Communicating Artery Fenestration Mistaken for an Aneurysm: A Cautionary Tale

This report portrays a case of a funnel shaped anterior communicating artery (ACoA) fenestration which was mistaken as a small A1 aneurysm in a subarachnoid hemorrhage case. Although tridimensional rotational digital subtraction angiography improves aneurysm diagnosis specially at the ACoA complex, current spatial resolution might leave behind a considerable percentage of ACoA fenestrations. This may lead to diagnostic errors and unnecessary treatments risking iatrogenic complications. Luckily for our patient, a concomitant aneurysm warranted clipping and subsequent surgical exploration of the ACoA complex revealed the pitfall, thus preventing further action. Interestingly, another group of authors who reported similar misdiagnosis with ACoA aneurysms were able to prevent a third error, thanks to the experience acquired with 2 prior cases. Therefore, this clinical image aims to raise wider awareness of the need for very cautious consideration of imaging depicting small and/or atypical aneurysms in the ACoA complex.

Letter to the Editor Regarding “Clinical Utility of Routine Postprocedural Computed Tomography of the Head Following Elective Neuroendovascular Interventions”

This report portrays a case of a funnel shaped anterior communicating artery (ACoA) fenestration which was mistaken as a small A1 aneurysm in a subarachnoid hemorrhage case. Although tridimensional rotational digital subtraction angiography improves aneurysm diagnosis specially at the ACoA complex, current spatial resolution might leave behind a considerable percentage of ACoA fenestrations. This may lead to diagnostic errors and unnecessary treatments risking iatrogenic complications. Luckily for our patient, a concomitant aneurysm warranted clipping and subsequent surgical exploration of the ACoA complex revealed the pitfall, thus preventing further action. Interestingly, another group of authors who reported similar misdiagnosis with ACoA aneurysms were able to prevent a third error, thanks to the experience acquired with 2 prior cases. Therefore, this clinical image aims to raise wider awareness of the need for very cautious consideration of imaging depicting small and/or atypical aneurysms in the ACoA complex.

Validation of SART 3.5D algorithm for cerebrovascular dynamics and artery versus vein classification in presurgical 3D digital subtraction angiographies

Classification of arteries and veins in cerebral angiograms can increase the safety of neurosurgical procedures, such as StereoElectroEncephaloGraphy, and aid the diagnosis of vascular pathologies, as arterovenous malformations. We propose a new method for vessel classification using the contrast medium dynamics in rotational digital subtraction angiography (DSA). After 3D DSA and angiogram segmentation, contrast enhanced projections are processed to suppress soft tissue and bone structures attenuation effect and further enhance the CM flow. For each voxel labelled as vessel, a time intensity curve (TIC) is obtained as a linear combination of temporal basis functions whose weights are addressed by simultaneous algebraic reconstruction technique (SART 3.5D), expanded to include dynamics. Each TIC is classified by comparing the areas under the curve in the arterial and venous phases. Clustering is applied to optimize the classification thresholds. On a dataset of 60 patients, a median value of sensitivity (90%), specificity (91%), and accuracy (92%) were obtained with respect to annotated arterial and venous voxels up to branching order 4–5. Qualitative results are also presented about CM arrival time mapping and its distribution in arteries and veins respectively. In conclusion, this study shows a valuable impact, at no protocol extra-cost or invasiveness, concerning surgical planning related to the enhancement of arteries as major organs at risk. Also, it opens a new scope on the pathophysiology of cerebrovascular dynamics and its anatomical relationships.

The Hybrid Operative Suite with Intraoperative Biplane Rotational Angiography in Pediatric Cerebrovascular Neurosurgery: Utility and Lessons Learned

Introduction: The benefits of performing open and endovascular procedures in a hybrid neuroangiography surgical suite include confirmation of treatment results and reduction in number of procedures, leading to improved efficiency of care. Combined procedural suites are infrequently used in pediatric facilities due to technical and logistical limitations. We report the safety, utility, and lessons learned from a single-institution experience using a hybrid suite equipped with biplane rotational digital subtraction angiography and pan-surgical capabilities. Methods: We conducted a retrospective review of consecutive cases performed at our institution that utilized the hybrid neuroangiography surgical suite from February 2020 to August 2021. Demographics, surgical metrics, and imaging results were collected from the electronic medical record. Outcomes, interventions, and nuances for optimizing preoperative/intraoperative setup and postoperative care were presented. Results: Eighteen procedures were performed in 17 patients (mean age 13.4 years, range 6–19). Cases included 14 arteriovenous malformations (AVM; 85.7% ruptured), one dural arteriovenous fistula, one mycotic aneurysm, and one hemangioblastoma. The average operative time was 416 min (range 321–745). There were no intraoperative or postoperative complications. All patients were alive at follow-up (range 0.1–14.7 months). Five patients had anticipated postoperative deficits arising from their hemorrhage, and 12 returned to baseline neurological status. Four illustrative cases demonstrating specific, unique applications of the hybrid angiography suite are presented. Conclusion: The hybrid neuroangiography surgical suite is a safe option for pediatric cerebrovascular pathologies requiring combined surgical and endovascular intervention. Hybrid cases can be completed within the same anesthesia session and reduce the need for return to the operating room for resection or surveillance angiography. High-quality intraoperative angiography enables diagnostic confirmation under a single procedure, mitigating risk of morbidity and accelerating recovery. Effective multidisciplinary planning enables preoperative angiograms to be completed to inform the operative plan immediately prior to definitive resection.

Improved Cerebral Arteriovenous Malformation Obliteration With 3-Dimensional Rotational Digital Subtraction Angiography for Radiosurgical Planning: A Retrospective Cohort Study

Anderson, Joshua L BS; Khattab, Mohamed H MD; Sherry, Alexander D BS; Luo, Guozhen MS; Chitale, Rohan V MD; Froehler, Michael T MD, PhD; Fusco, Matthew R MD; Cmelak, Anthony J MD; Attia, Albert MD

Preoperative simulation of a middle cerebral artery aneurysm clipping using a rotational three-dimensional digital subtraction angiography.

Background: In recent years, young neurosurgeons have had few opportunities to gain experience with clipping surgeries. The first author was sometimes surprised that she could not predict the anatomical relationships between the aneurysm and vessels during actual surgery. This study investigated the differences between the expected and actual operative findings during clipping surgery for aneurysms of the middle cerebral artery.Methods: Medical records for 15 patients who underwent rotational three-dimensional (3D) digital subtraction angiography (3D-DSA) before the clipping surgery were analyzed after the surgery. The anatomical relationships between the aneurysm and parent arteries were defined by the intraoperative findings just before clipping. The viewing direction to obtain this definitive perspective (virtual viewing direction) was measured. The angle between this viewing direction and the coordinate axis was denoted as the “virtual angle for clipping (VAC).”Results: The VAC between the X-axis and viewing direction on the XY-plane (VAC-XY) ranged from –43° to +73° (mean, +27°), and the angle between the XY-plane and viewing direction (VAC-Z) ranged from +25° to –34° (mean, 5.5°). The difference between the VAC-XY and mean angle was significantly larger in cases with hidden branches behind the aneurysm. In these cases, the virtual viewing direction visualized the neck of the aneurysm. There is no correlation between M1 length and VAC-XY or VAC-Z discrepancy.Conclusion: 3D-DSA or 3D computed tomography angiography images visualizing the neck of the aneurysm should be obtained in combination with images obtained from the standard oblique angle.

A New Method of Microcatheter Heat-Forming for Cerebral Aneurysmal Coiling Using Stereolithography Three-Dimensional Printed Hollow Vessel Models.

To perform successful coil embolization of cerebral aneurysms, it is crucial to make an appropriately shaped microcatheter tip for an aneurysm and its parent artery. So far, we manually shaped a mandrel by referencing two-dimensional (2D) images of a rotation digital subtraction angiography (DSA) on a computer screen. However, this technique requires a lot of experience, and often involves trial and error. Recently, there have been increasing reports of manual mandrel shaping using a full-scale three-dimensional (3D) model of an aneurysm and its parent artery output by various types of 3D printer. We have further developed this method by producing a hollow model of an aneurysm and its parent artery with a stereolithography 3D printer and inserting a mandrel inside the model to fit and stabilize a microcatheter tip. Based on digital imaging and communications in medicine (DICOM) data obtained by rotational DSA, 3D images of an aneurysm and its parent artery were created and converted into standard triangulated language (STL) data. A hollow model was produced by extruding the STL data outward in the normal direction, and then a hole was made at the tip of the aneurysm using these STL data. We output these STL data to a stereolithography 3D printer. After cleaning and sterilizing the model, the mandrel was inserted in the direction of the parent artery through the hole made in the tip of the aneurysm and pushed in, creating the ideal mandrel shape. Twelve cases (14 aneurysms) were included in this study. A microcatheter tip was shaped by this method for patients who were scheduled to undergo coil embolization for an unruptured aneurysm. In 13 of the 14 aneurysms, the microcatheter was easily guided into the aneurysms in one or two trials, the position of the microcatheter tip in the aneurysm was appropriate, and the stability during coil embolization was high. Our method differs from the conventional one in that a hollow model made of resin is produced with a stereolithography 3D printer and that the mandrel is shaped by inserting it retrogradely into the hollow model. Using our new method, it will be possible to shape the tip of a microcatheter suitable for safe and stable coil embolization without relying on an operator's experience.

Commentary: Improved Cerebral Arteriovenous Malformation Obliteration With 3-Dimensional Rotational Digital Subtraction Angiography for Radiosurgical Planning: A Retrospective Cohort Study.

Commentary: Improved Cerebral Arteriovenous Malformation Obliteration With 3-Dimensional Rotational Digital Subtraction Angiography for Radiosurgical Planning: A Retrospective Cohort Study.

Improved Cerebral Arteriovenous Malformation Obliteration With 3-Dimensional Rotational Digital Subtraction Angiography for Radiosurgical Planning: A Retrospective Cohort Study.

Stereotactic radiosurgery (SRS) for cerebral arteriovenous malformations (AVMs) is well-established. Radiographic advantages exist for 3-dimensional rotational digital subtraction angiography (3DRA) over 2-dimensional digital subtraction angiography (2D DSA) in delineating AVM nidus structure for SRS treatment planning. However, currently there is limited to no data directly comparing 2D DSA versus 3DRA in terms of patient outcomes. To investigate whether the use of 3DRA over 2D DSA in radiosurgical treatment planning for AVMs associates with improved clinical outcomes. All AVM patients treated with SRS at our institution between the years 2000 and 2018 were identified. Primary outcomes were obliteration rates and time to obliteration (TTO); secondary outcomes included rates of post-SRS hemorrhage, salvage therapy, and symptomatic radionecrosis. A minimum of 12 mo of follow-up imaging/angiogram post-SRS was required, or alternatively evidence of obliteration on angiogram prior to 12 mo post-SRS. Single predictor and multivariable Cox regression and logistic regression models were constructed to test for association between radiographic, clinical, and treatment factors with outcomes. A total of 75 patients were included. Total 17 patients received 3DRA and 58 patients received 2D DSA, with a median follow-up of 3.29 yr. The 3DRA is significantly associated with improved TTO on single predictor (HR 2.87, 1.29-6.12; P=.0109) and multivariable analysis (HR 2.448, 1.076-5.750; P=.0330) and increased odds of achieving obliteration by 3 yr post-SRS on single predictor analysis (OR 6.044, 1.405-26.009; P=.0157). The 3DRA over 2D DSA in SRS treatment planning for AVMs may result in improved TTO and 3-yr obliteration rates. Further investigation and prospective study are warranted.

Deep learning based detection of intracranial aneurysms on digital subtraction angiography: A feasibility study.

Digital subtraction angiography is the gold standard for detecting and characterising aneurysms. Here, we assess the feasibility of commercial-grade deep learning software for the detection of intracranial aneurysms on whole-brain anteroposterior and lateral 2D digital subtraction angiography images. Seven hundred and six digital subtraction angiography images were included from a cohort of 240 patients (157 female, mean age 59 years, range 20-92; 83 male, mean age 55 years, range 19-83). Three hundred and thirty-five (47%) single frame anteroposterior and lateral images of a digital subtraction angiography series of 187 aneurysms (41 ruptured, 146 unruptured; average size 7±5.3 mm, range 1-5 mm; total 372 depicted aneurysms) and 371 (53%) aneurysm-negative study images were retrospectively analysed regarding the presence of intracranial aneurysms. The 2D data was split into testing and training sets in a ratio of 4:1 with 3D rotational digital subtraction angiography as gold standard. Supervised deep learning was performed using commercial-grade machine learning software (Cognex, ViDi Suite 2.0). Monte Carlo cross validation was performed. Intracranial aneurysms were detected with a sensitivity of 79%, a specificity of 79%, a precision of 0.75, a F1 score of 0.77, and a mean area-under-the-curve of 0.76 (range 0.68-0.86) after Monte Carlo cross-validation, run 45 times. The commercial-grade deep learning software allows for detection of intracranial aneurysms on whole-brain, 2D anteroposterior and lateral digital subtraction angiography images, with results being comparable to more specifically engineered deep learning techniques.

Abstract WP129: The Heat Grading Scale as a Neurovascular Remodeling Based Score in Aneurysms Treated With Flow Diversion

Objective: To apply principles of neurovascular remodeling in the classification of flow diverted aneurysms to predict outcomes using the HEAT (Hemodynamics, Endothelialization and Aneurysmal Thrombosis) grading scale. Introduction: The goal of flow diversion is to exclude an aneurysm from circulation through endothelialization of the aneurysmal neck and hemodynamic induction of aneurysmal thrombosis. Current grading scales do not include the above parameters to evaluate aneurysms after flow diversion. Methods: Reconstructions using 360° virtual reality (VR) models based on volumetric digital subtraction angiography (DSA) scans of unruptured, wide-neck intracranial aneurysms treated with Pipeline™ from March 2010 to May 2018 at our comprehensive stroke center were built using Surgical Theatre ® . The HEAT grading scale was used to generate a 0 to 15-point score that evaluated residual filling (none 0%, entry remnant <5%, subtotal 5-95%, total >95%), stasis phase (persistent contrast at venous phase, clearance before venous phase, arterial clearance before capillary phase), endoleak (absence, presence), free-hanging edge (absent, present without thrombus, present with thrombus), in-stent stenosis (0-29% minimal, 30-49% mild, 50-69% moderate, 70-94% severe, 95-99% critical), and branch filling (complete, partial TICI 2b >50%, partial TICI 2a <50%, insufficient). Each case was assigned a HEAT score by four neurointerventionalists using DSA, CT angiography (CTA), and the VR model. Results: Fifty out of 86 Pipeline™ cases had 3D rotational DSA and met technical standards required to build the VR model. Clinical adverse events including central retinal artery occlusion, middle cerebral artery syndrome, and amaurosis fugax were positively associated with HEAT score (n=3, p=<0.001) as were subclinical adverse events including endoleak (n=2) and free-hanging edge with thrombus (n=2) (p=<0.001). Interrater variability was high (k=0.8). Conclusion: The HEAT grading scale is sensitive, reproducible, and associated with clinical outcome. Larger prospective studies are warranted to validate our results.

Amended Intraoperative Neuronavigation: Three-Dimensional Vascular Roadmapping with Selective Rotational Digital Subtraction Angiography

Accuracy of intraoperative cerebrovascular neuronavigation is difficult to maintain because of the ongoing need for brain shift correction. By including 3-dimensional rotational intraoperative digital subtraction angiography (3D-iDSA), the intraoperative cerebrovascular neuronavigation can be updated and upgraded throughout the microneurosurgical procedure. The aim of this technical note is to demonstrate the feasibility and advantage of updating and upgrading the accuracy of targeted cerebrovascular neuronavigation with an intraoperative 3D-DSA dataset. A preoperative diagnostic selective 3D-DSA was registered with the neuronavigation software, followed by the automated segmentation of the vascular object of interest (an aneurysm in this case). After acquiring additional 3D-iDSA volumes, these steps were repeated, thereby updating the cerebrovascular roadmap and neuronavigation accuracy (i.e., brain shift correction). This technique was applied successfully in a patient who underwent elective microneurosurgical clipping of a right-sided middle cerebral artery (MCA) bifurcation aneurysm in a hybrid neurosurgical operating setting. After clipping of the MCA aneurysm, a selective 3D iDSA was performed that was then used to update the projection and accuracy of the initial 3D neurovascular object of interest (i.e., the aneurysm). In this revised rotational view, the projection refined the target segments of the clipped MCA aneurysm, the accuracy of clipping, and brain shift correction. 3D-iDSA vascular segmentations can update und upgrade the intraoperative neurovascular roadmap by thereby enhancing accuracy of cerebrovascular neuronavigation, as well as correcting brain shift. This technique is feasible within the hybrid operation room. Evaluation in larger series is required to support these findings.

3D rotational DSA: Diagnostic and therapeutic approach to cerebral aneurysms

Background and purpose: Digital subtraction angiography (DSA), a minimally invasive procedure for an exceptional visualization of cerebrovascular angioarchitecture, has become an important imaging technique for inclusive evaluation and therapeutic embolization. Our purpose is to share the importance of DSA for evaluation of cerebral aneurysms.
 Material and method: A total of 148 patients with suspected intracranial aneurysm underwent digital subtraction angiography during January 2005 to December 2009. Preliminarily aortogram was considered in old age group (>50yrs) before supra-aortic angiography. Patient’s selection criterion included both ruptured and unruptured aneurysms. 3D rotational effect was applied for all complex cerebral aneurysms with unfavorable dome neck ratio. DSA was accomplished into 2- 6 standard projections for every vascular territory for optimal visualization and accurate evaluation of cerebral aneurysms.
 Result: 21 were males and 48 were females. Age difference was ranged between 26-78 years with an average of 51.5years. Among 288 patients, total detected aneurysms were 480. 32 presented with SAH, 21 presented with headache and 14 patients came with cranial nerve dysfunction during admission. 3 had negative angiography irrespective to spontaneous subarachnoid hemorrhage. Delineation of aneurysmal neck improved with rotation effect of 3D DSA in 80% of patients. Parent vessel and its relationship to adjacent vessels was better demonstrated with rotational angiography in >50% of cases. Endovascular embolization was done in 80 patients in same setting.
 Conclusion: DSA with 3D rotational technique is an essential radio-imaging tool for accurate characterization of cerebrovascular diseases and subsequently beneficial to elaborate on their potential treatment protocols.

Impact of Risk Factors on the Size of Ruptured Intracranial Saccular Aneurysms

Background: Un-ruptured intracranial aneurysms (UIAs) are common and prevalence is about 2 to 8%. Several studies have shown that the decision to treat un-ruptured aneurysms should not be based on aneurysm size alone. A study suggest that treatment of UIAs smaller than 7 mm in hypertensive patients and smokers may be beneûcial.
 Aim and objective: The goal of this study is analysis of correlation of age, gender, location of the aneurysm, history of hypertension and cigarette smoking, previous history of SAH with the size of ruptured aneurysms.
 Materials and Methods: This hospital based observational cross-sectional study was conducted in the Department of Neurology & Neurosurgery, Dhaka Medical College Hospital (DMCH), Dhaka. Total 44 patients with SAH were taken by inclusion & exclusion criteria. The aneurysms size, site of location and aneurysm multiplicity was assessed by three-dimensional rotational digital subtraction angiography (DSA).
 Results:The mean age of the study population was 49.24 ±11.5. About half of the population were within 51-60 years. The male female ratio was 1:1.2. Out of 44 population, 93.2% were presented with headache, 90.9% with vomiting. In this study aneurysms mean size was 5.72±4.010 mm. 93.2% of aneurysms were below 10 mm, 75.0% were below 7 mm and 50.0% below 5 mm. Size of ruptured aneurysm is small in hypertensive population and is significant (p-value 0.037). Aneurysm size was significantly (p- value 0.013) smaller in case of smoker. Mean aneurysm size in hypertensive smoker population was significantly (p-value-0.004) smaller than hypertensive non-smoker. Population with one risk factor had mean aneurysm size was 8.32±6.84 mm, two risk factors had 5.26±1.86mm, three risk factors had 4.79±2.05 mm and more than three risk factors had 2.85±1.43.
 Conclusion: This study shows that more the risk factors, smaller the size of aneurysms. Therefore, history of hypertension, cigarette smoking, female sex, age and positive family history should be considered in the assessment of treatment of un-ruptured intracranial aneurysms.
 Bangladesh Journal of Neuroscience 2019; Vol. 35 (2): 86-94

Relationship between Injection Rate and Contrast Enhancement on Three-dimensional Digital Subtraction Angiography of the Cerebral Arteries

Objective:Three-dimensional (3D) digital subtraction angiography (DSA) is becoming a common technique for the assessment of the cerebral arteries. Nevertheless, the injection parameters for each artery are not standardized among institutions. The objective of this study was to analyze the relationship between injection rate and contrast enhancement on 3D DSA of the common carotid artery.Materials and methods:Twenty-four patients who underwent 3D DSA of the common carotid artery from June 2013 to March 2015 were included in this retrospective study. Contrast enhancement of each patient was analyzed for four cerebral arteries segments (A1, A2, M1 and M2) by measuring the average pixel value on the source rotational two-dimensional DSA images. Linear regression analysis was used to investigate the correlation between injection rate and contrast enhancement.Results:All four regression lines showed that a higher injection rate led to higher contrast enhancement. There was a significant relationship for the A1, A2 and M1 segments (P = 0.008, 0.03 and < 0.001) but not for the M2 segment (P = 0.13). The goodness-of-fit of the regression lines was high for the M1 segment (R2 = 0.63). However, as the size of the vascular lumen became narrower, the value for the A1 (R2 = 0.28) and A2 (R2 = 0.19) segments became lower.Conclusion:In 3D DSA of the common carotid artery, contrast enhancement of a relatively wide lumen could be optimized by adjusting the injection rate. However, it is difficult to optimize the contrast enhancement of a relatively narrow lumen only by adjusting the injection rate.

Wall enhancement of intracranial unruptured aneurysm is associated with increased rupture risk and traditional risk factors.

Aneurysm wall enhancement (AWE) on MRI has been considered an imaging marker to indicate active aneurysm inflammation, but no prospective studies have assessed the ability of AWE to predict rupture risk or growth. We aim to study the association of AWE with traditional risk factors and the estimated rupture risk. Seventy-seven patients (mean age, 58.4 ± 10.8 years; 57% female) with 88 asymptomatic intracranial saccular aneurysms underwent both 3-T high-resolution MRI and three-dimensional (3D) rotational digital subtraction angiography (DSA). Geometric and morphologic parameters were measured on DSA, and the degree of AWE on MRI was graded. One- and 5-year rupture risks of aneurysms were estimated using the UCAS and PHASES calculator. Parameters associated with AWE were analyzed using uni- and multivariate logistic regression. Non-internal carotid artery location (OR 3.4, 95% CI 1.6-7.1) and aneurysm size (OR 1.9, 95% CI 1.3-2.7) were independently associated with AWE (p < 0.05). Aneurysms with AWE had significantly higher estimated rupture risk (1 and 5 year, 1.9% and 5.8%) than aneurysms without AWE (0.5% and 2.1%) (p < 0.001). Stronger and larger areas of AWE were correlated with the aneurysm size, size ratio and estimated rupture risk (R2 ≥ 0.30) (p < 0.01). Prospective assessment of asymptomatic intracranial aneurysms with MRI suggests that AWE is associated with traditional risk factors and estimated short- and medium-term rupture risk. • AWE independently associates with aneurysm location and size. • Aneurysms with AWE have higher rupture risk than aneurysms without AWE. • Stronger and larger areas of AWE correlated with the aneurysm size, size ratio and rupture risk.

Unique Angiographic Appearances of Moyamoya Disease Detected with 3-Dimensional Rotational Digital Subtraction Angiography Imaging Showing the Hemodynamic Status

The aim of this study was to identify the unique morphological arterial features in patients with moyamoya disease on 3-dimensional rotational digital subtraction angiography. One hundred seven hemispheres of 58 consecutive patients with moyamoya disease that were analyzed with fused 3-dimensional images of internal carotid angiograms and vertebral angiograms that were marked with different colors were reviewed. Angiographic findings in the posterior watershed area were classified, and the utility of the classification was analyzed by comparing it with clinical presentations and quantitative hemodynamic parameters obtained with positron emission tomography. Two unique angiographic appearances were identified. A vacant vessel appearance (no arterial inflow despite absence of cortical infarction) was observed mostly in transient ischemic attack hemispheres. In hemispheres with a vacant vessel appearance, cerebral blood flow was decreased, cerebral blood volume was increased, and mean transit time was prolonged significantly (P = .00017, P = .0061, and P = .00026, respectively). A cocktail vessel appearance (mixture of carotid and vertebral arterial flow) was most commonly observed in asymptomatic cases, as well as in ischemic hemispheres. Cerebral blood volume increased and mean transit time was prolonged significantly (P = .036 and P = .014, respectively) in hemispheres with a cocktail vessel appearance. The trend of progression in hemodynamic severity in the order of normal appearance, cocktail vessel appearance, and vacant vessel appearance in the watershed area was statistically significant. Fused 3-dimensional digital subtraction angiography demonstrated unique angiographic features in the watershed area, and this represented the degree of cerebral hemodynamic impairment in moyamoya disease.

Application of low injection rate and low contrast agent dose in three-dimensional rotational digital subtraction angiography of the intracranial aneurysm.

The objective of this article is to explore the feasibility of low injection rate and low contrast agent dose in three-dimensional rotational digital subtraction angiography (3D DSA) of the intracranial aneurysm. Fifty-one patients with suspected intracranial aneurysms were included. The catheter tip was kept within the internal carotid artery at the epistropheus level. Patients were divided into three groups randomly according to injection rate: group A (1.5 ml/s, n = 18), group B (2.0 ml/s, n = 18), and group C (3.0 ml/s, n = 15). The noise, signal-to-noise ratio (SNR), and carrier-to-noise ratio (CNR) of C2, C6, M1, and A1 segments were calculated. The continuous subtraction images and reconstructed images were evaluated by two technicians. No significant differences were found in noise between groups A and B, and groups A and C. Significant differences were found in the SNR and CNR of M1 and A1 segments between groups A and B, and groups B and C, but for C2 and C6 segments, they were not significant. Significant differences were found in the SNR and CNR of all segments between groups A and C. Significant differences were found in the contrast agent dose between all three groups. No significant differences were found in scores evaluated by two physicians between the three groups. The personalized injection protocol of low injection rate and low contrast agent dose in 3D DSA of the intracranial aneurysm is feasible. The application of this protocol can reduce the dose of iodine and obtain satisfactory images.