Head CT Angiography Research Articles

Pre-treatment spectral CT combined with CT perfusion can predict hemorrhagic transformation after thrombolysis in patients with acute ischemic stroke

ObjectiveTo investigate the value of pre-treatment spectral CT angiography (CTA) in predicting hemorrhagic transformation (HT) after intravenous thrombolysis (IVT) treatment in acute ischemic stroke (AIS) patients. Materials and MethodsAIS patients who underwent IVT with recombinant tissue plasminogen activator and pre-treatment head and neck spectral CTA and head CT perfusion (CTP) from January 2018 to June 2020 were reviewed retrospectively. Finally, 20 patients were included in the HT group and 22 age-matched patients were included in the non-HT group. Spectral and CTP parameters of the region of interest on pre-treatment CTA axial raw images and CTP images, including the infarct core (IC) and ischemic penumbral (IP) regions, were recorded. The differences in clinical variables, CTP, collateral scores and spectral parameters between the two groups were analyzed. Three multivariate logistic regression models were then developed, where model 1 included clinical and spectral parameters, model 2 included clinical and CTP parameters and a combined model included clinical, CTP, and spectral parameters. Receiver operating characteristic analysis was used to evaluate the performance of the multivariate model. ResultsPatients with HT had higher Safe Implementation of Treatments in Stroke (SITS) score (p = 0.023), the volume of perfusion lesions (p = 0.005), the volume of IP (p = 0.003), the mean transit time (MIT) in the IC area (p = 0.012), as well as the TTP in IP area (p = 0.015) compared with patients without HT. The HT group showed significantly lower CBF in the IC area (p = 0.019), iodine concentration (p = 0.017) and the effective atomic number (p = 0.024) in the IP area than non-HT group. And the slope of the spectral curve of the HT group in the IP region was larger than that of the non-HT group (p = 0.023). Gender, age, SITS score, the volume of entire perfusion lesion, CBF and MIT in the IC area, TTP in the IP area, as well as iodine concentration in the IP area were included in the final multivariate model for predicting HT. And CBF in the IC area (OR = 0.779, 95 % CI:0.609–0.996, p = 0.046) as well as the iodine concentration of IP area (OR = 0.343, 95 % CI: 0.131–0.901, p = 0.030) were proved to be independent predictors for HT. The combined model including clinical, spectral, and CTP parameters, showed improved accuracy compared to the other two models, while the Delong test did not suggest a statistically significant difference (both p values > 0.05). ConclusionsThe iodine concentration of IP area derived from pre-treatment spectral CTA was an independent predictor of HT after IVT treatment for AIS patients. Moreover, multivariate models combined with clinical, spectral, and CTP parameters may be able to predict HT.

Meta-Analysis of Prognostic Correlation of Thrombectomy for Cerebral Infarction Based on Intelligent Medical Treatment.

A meta-analysis is used to investigate the correlation between the status of collateral circulation assessed by head CT angiography (CTA) and the outcome of thrombectomy for cerebral infarction. Meta-analysis is conducted. The experimental results show that the National Institutes of Health Stroke Scale (NIHSS) score, modified Rankin Scale (mRS) score, incidence of cerebral hemorrhage, and mortality in the group with good collateral circulation are significantly lower than those in the group with bad collateral circulation, and the rate of good prognosis is significantly higher (P < 0.05). The evaluation and treatment of patients with cerebral infarction and their prognosis based on CTA intelligent medical technology are related to collateral circulation, and the effect of effectively reducing the risk of death, cerebral hemorrhage, and neurological function injury and improving the prognosis is more obvious in each collateral circulation.

Comparison of two different GSI scanning protocols in head and neck CT angiography: Image quality and radiation dose.

To compare image quality and radiation dose of computed tomography angiography (CTA) of the head and neck in patients using two Gemstone Spectral Imaging (GSI) scanning protocols. A total of 100 patients who underwent head-neck CTA were divided into two groups (A and B) according to the scanning protocols, with 50 patients in each group. The patients in group A underwent GSI scanning protocol 1 (GSI profile: head and neck CTA), while those in group B underwent GSI scanning protocol 2 (GSI profile: chest 80 mm). All images were reconstructed using 40% and 70% pre- and post-adaptive level statistical iterative reconstruction V (pre-ASiR-V and post-ASiR-V) algorithms, respectively. The CT dose index (CTDIvol) and dose-length (DLP) product were recorded and the mean value was calculated and converted to the effective dose. CT values, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of all images were calculated. Additionally, subjective image evaluation was conducted by two independent radiologists using a five-point scoring method. All data were statistically analyzed. There were no significant differences in the CT values, SNR, CNR, and subjective score between groups A and B (p > 0.05); however, the mean effective dose (1.2±0.1 mSv) in group B was 45.5% lower than that in group A (2.2±0.2 mSv) (p < 0.05). GSI scanning protocol 2 could more effectively reduce the radiation dose in head-neck CT angiography while maintaining image quality compared to GSI scanning protocol1.

Protocol and Preliminary Results of the Establishment of Intracranial Aneurysm Database for Artificial Intelligence Application Based on CTA Images.

Background and PurposeUnruptured intracranial aneurysms (UIAs) are increasingly being detected in clinical practice. Artificial intelligence (AI) has been increasingly used to assist diagnostic techniques and shows encouraging prospects. In this study, we reported the protocol and preliminary results of the establishment of an intracranial aneurysm database for AI application based on computed tomography angiography (CTA) images.MethodsThrough a review of picture archiving and communication systems, we collected CTA images of patients with aneurysms between January 2010 and March 2021. The radiologists performed manual segmentation of all diagnosed aneurysms on subtraction CTA as the basis for automatic aneurysm segmentation. Then, AI will be applied to two stages of aneurysm treatment, namely, automatic aneurysm detection and segmentation model based on the CTA image and the aneurysm risk prediction model.ResultsThree medical centers have been included in this study so far. A total of 3,190 cases of CTA examinations with 4,124 aneurysms were included in the database. All identified aneurysms from CTA images that enrolled in this study were manually segmented on subtraction CTA by six readers. We developed a structure of 3D-Unet for aneurysm detection and segmentation in CTA images. The algorithm was developed and tested using a total of 2,272 head CTAs with 2,938 intracranial aneurysms. The recall and false positives per case (FP/case) of this model for detecting aneurysms were 0.964 and 2.01, and the Dice values for aneurysm segmentation were 0.783.ConclusionThis study introduces the protocol and preliminary results of the establishment of the intracranial aneurysm database for AI applications based on CTA images. The establishment of a multicenter database based on CTA images of intracranial aneurysms is the basis for the application of AI in the diagnosis and treatment of aneurysms. In addition to segmentation, AI should have great potential for aneurysm treatment and management in the future.

Stenosis of Azygos Anterior Cerebral Artery Results in Bilateral Anterior Cerebral Artery Strokes.

HomeStrokeVol. 53, No. 10Stenosis of Azygos Anterior Cerebral Artery Results in Bilateral Anterior Cerebral Artery Strokes Free AccessCase ReportPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessCase ReportPDF/EPUBStenosis of Azygos Anterior Cerebral Artery Results in Bilateral Anterior Cerebral Artery Strokes Diana Yang, Brian Behdad Miremadi, Anton Mlikotic and Kassi Kronfeld Diana YangDiana Yang Correspondence to: Diana Yang, DO, Harbor-UCLA Medical Center, 1000 W. Carson St, Building N-25, Torrance, CA 90502. Email E-mail Address: [email protected] https://orcid.org/0000-0001-6695-1771 Department of Neurology (D.Y., B.B.M., K.K.), Harbor-UCLA Medical Center, Torrance, CA. Search for more papers by this author , Brian Behdad MiremadiBrian Behdad Miremadi Department of Neurology (D.Y., B.B.M., K.K.), Harbor-UCLA Medical Center, Torrance, CA. Search for more papers by this author , Anton MlikoticAnton Mlikotic Department of Radiology (A.M.), Harbor-UCLA Medical Center, Torrance, CA. Search for more papers by this author and Kassi KronfeldKassi Kronfeld Department of Neurology (D.Y., B.B.M., K.K.), Harbor-UCLA Medical Center, Torrance, CA. Search for more papers by this author Originally published15 Jul 2022https://doi.org/10.1161/STROKEAHA.122.040216Stroke. 2022;53:e448–e449Other version(s) of this articleYou are viewing the most recent version of this article. Previous versions: July 15, 2022: Ahead of Print KEY POINTAlthough much rarer than unilateral extremity weakness, bilateral lower extremity weakness may still result from a stroke—specifically due to vascular compromise of an azygos anterior cerebral artery.A 55-year-old female presented with 1 week of acute onset bilateral lower extremity weakness and reduced speech output. Examination was notable for spastic paralysis of lower extremities, trace weakness in bilateral shoulder abduction, and abulia. Magnetic resonance imaging revealed bilateral anterior cerebral artery (ACA) territory strokes. Computed tomography angiography demonstrated absence of the anterior communicating artery, a hypoplastic right ACA precommunicating segment (A1), azygos continuation of a dominant left ACA, and focal stenosis in the lone A2 segment.ACA territory infarcts only account for 1.8% of cerebral infarcts, and bilateral ACA infarcts are even less common.1 Azygos ACA is a rare circle of Willis variant (0.3%–2% of the population) notable for an absent anterior communicating artery and one ACA postcommunicating segment (A2) feeding both ACA territories.2 Despite the initial difficult localization, bilateral lower extremity weakness may still result from a stroke, specifically due to vascular compromise of an azygos ACA (Figure).Download figureDownload PowerPointFigure. Brain magnetic resonance imaging and head computed tomography angiography. Bilateral anterior cerebral artery (ACA) territory diffusion restriction on magnetic resonance imaging diffusion-weighted imaging (DWI) sequence (A) with corresponding hyperintensity on fluid-attenuated inversion recovery (FLAIR) sequence (B). Three-dimensional computed tomography angiography (C and D) demonstrates 2 anatomic variants: hypoplastic right A1 segment (short arrow) with dominant left ACA and an absent anterior communicating artery. There is significant focal stenosis in the A2 segment (long arrows).Article InformationSources of FundingNone.Disclosures None.FootnotesFor Sources of Funding and Disclosures, see page e449.Correspondence to: Diana Yang, DO, Harbor-UCLA Medical Center, 1000 W. Carson St, Building N-25, Torrance, CA 90502. Email [email protected]lacounty.gov

The effect of axis pedicle and intra-axial vertebral artery on C 2 pedicle screw placement

To investigate the influence of axis pedicle and intra-axial vertebral artery (IAVA) alignment on C 2 pedicle screw placement by measuring the data of head and neck CT angiography. The axis pedicle diameter (D), isthmus height (H), isthmus thickness (T), and IAVA alignment types were measured in 116 patients (232 sides) who underwent head and neck CT angiography examinations between January 2020 and June 2020. Defined the IAVA offset direction by referencing the vertical line through the center of C 3 transverse foramen on the coronal scan, it was divided into lateral (L), neutral (N), and medial (M). Defined the IAVA high-riding degree by referencing the horizontal line through the outlet of the C 2 transverse foramen, it was divided into below (B), within (W), and above (A). The rate of pedicle stenosis, high-riding vertebral artery, and different IAVA types were calculated, and their relationships were analysed. Simulative C 2 pedicle screws were implanted by Mimics 19.0 software, and the interrelation among the rates of pedicle stenosis, high-riding vertebral artery, IAVA types, and vertebral artery injury were analyzed. The rate of C 2 pedicle stenosis was 33.6% (78/232), and the rate of high-riding vertebral artery was 35.3% (82/232). According to the offset direction and the degree of riding, IAVA was divided into 9 types, among which the N-W type (29.3%) was the most, followed by the L-W type (19.0%) and the L-B type (12.9%), accounting for 60.9%. The vertebral artery injury rate of simulative implanted C 2 pedicle screws was 35.3% (82/232). The vertebral artery injury rate in patients with pedicle stenosis and high-riding vertebral artery was significantly higher than that who were not ( P<0.001). The rate of pedicle stenosis, high-riding vertebral artery, and vertebral artery injury were significantly different among IAVA types ( P<0.001), and M-A type was the most common. Vertebral artery injury is more common in pedicle stenosis and/or high-riding vertebral artery and/or IAVA M-A type. Preoperative head and neck CT angiography examination has clinical guiding significance.

Study on CT Angiography of Head and Neck Arteries in Cerebral Infarction with Vascular Stenosis

Study on CT Angiography of Head and Neck Arteries in Cerebral Infarction with Vascular Stenosis

Intra-arterial infusion of fasudil hydrochloride for cerebral vasospasm secondary to carotid artery stenting: illustrative case

BACKGROUNDHypoperfusion due to intracranial cerebral vasospasm after carotid artery stenting (CAS) is rare. The authors presented a case of selective intraarterial infusion of fasudil hydrochloride for cerebral vasospasm after CAS.OBSERVATIONSA 73-year-old man received CAS for asymptomatic right cervical internal carotid artery stenosis. Twelve hours after CAS, disturbance of consciousness, left hemiplegia, and right conjugate deviation appeared in the patient. Head computed tomography angiography showed diffuse vasospasm of the right middle cerebral artery (MCA). The authors hypothesized that the cause of the symptoms was hypoperfusion due to intracranial cerebral vasospasm. Medical treatment was started; however, the focal symptoms worsened rapidly. Therefore, the authors decided to infuse fasudil intraarterially. This treatment resulted in a remarkable improvement in blood flow and gradual recovery from neurological symptoms. Head magnetic resonance angiography on the day after fasudil infusion showed improved visualization of the right MCA. The neurological symptoms almost completely disappeared 22 hours after fasudil infusion (40 hours after CAS).LESSONSAs a complication after CAS, the possibility of hypoperfusion due to cerebral vasospasm should be considered. If symptoms due to hypoperfusion worsen even after medical treatment, intraarterial infusion of fasudil may be an effective option.

Optimization of the Parameters for the Test Bolus Technique in Computed Tomography Angiography of Head and Neck.

The aim of the study was to optimize low-dose scanning protocols for the test bolus technique in 64-detector computed tomography (CT) angiography (CTA) of the head and neck. A total of 250 patients were randomly divided into 5 groups of 50 patients each: conventional group (group A: 120 kV, 100 mA) and low-dose groups (group B: 100 kV, 100 mA; group C: 100 kV, 50 mA; group D: 80 kV, 100 mA; and group E: 80 kV, 50 mA). Subjective scores and objective measurements (CT values of the aortic arch, image noise, and signal-to-noise ratio) were used to evaluate the image quality and compare the radiation doses of the 5 groups. The image quality of the 5 groups met the diagnostic requirements, with no significant difference in the subjective evaluation findings (P > 0.05). There were significant differences in the CT values between the conventional group and low-dose groups (P < 0.05); however, there was no significant difference between groups B and C and between groups D and E (P > 0.05). Moreover, the volume CT dose index and dose length product of groups B, C, D, and E decreased by 37.62%, 70.45%, 65.28%, and 83.39%, respectively, compared with those of group A. Although the image noise of the low-dose groups increased, an appropriate reduction in the tube voltage enhanced the contrast medium-induced x-ray attenuation and increased the CT value, which resulted in a nonsignificant difference in the signal-to-noise ratio. Therefore, the image quality of the low-dose groups was not affected compared with that of the conventional group. In the test bolus technique in 64-detector CTA, the low-dose protocol of using 80 kV and 50 mA reduces the radiation dose by 83.39% compared with the conventional scan, without affecting the image quality.

AI software detection of large vessel occlusion stroke on CT angiography: a real-world prospective diagnostic test accuracy study

BackgroundArtificial intelligence (AI) software is increasingly applied in stroke diagnostics. However, the actual performance of AI tools for identifying large vessel occlusion (LVO) stroke in real time in a real-world...

Full field-of-view, high-resolution, photon-counting detector CT: technical assessment and initial patient experience

We report a comprehensive evaluation of a full field-of-view (FOV) photon-counting detector (PCD) computed tomography (CT) system using phantoms, and qualitatively assess image quality in patient examples. A whole-body PCD-CT system with 50 cm FOV, 5.76 cm z-detector coverage and two acquisition modes (standard: 144 × 0.4 mm collimation and ultra-high resolution (UHR): 120 × 0.2 mm collimation) was used in this study. Phantoms were scanned to assess image uniformity, CT number accuracy, noise power spectrum, spatial resolution, material decomposition and virtual monoenergetic imaging (VMI) performance. Four patients were scanned on the PCD-CT system with matched or lower radiation dose than their prior clinical CT scans performed using energy-integrating detector (EID) CT, and the potential clinical impact of PCD-CT was qualitatively evaluated. Phantom results showed water CT numbers within ±5 HU, and image uniformity measured between peripheral and central regions-of-interests to be within ±5 HU. For the UHR mode using a dedicated sharp kernel, the cut-off spatial frequency was 40 line-pairs cm−1, which corresponds to a 125 μm limiting in-plane spatial resolution. The full-width-at-half-maximum for the section sensitivity profile was 0.33 mm for the smallest slice thickness (0.2 mm) using the UHR mode. Material decomposition in a multi-energy CT phantom showed accurate material classification, with a root-mean-squared-error of 0.3 mg cc−1 for iodine concentrations (2–15 mg cc−1) and 14.2 mg cc−1 for hydroxyapatite concentrations (200 and 400 mg cc−1). The average percent error for CT numbers corresponding to the iodine concentrations in VMI (40–70 keV) was 2.75%. Patient PCD-CT images demonstrated better delineation of anatomy for chest and temporal bone exams performed with the UHR mode, which allowed the use of very sharp kernels not possible with EID-CT. VMI and virtual non-contrast images generated from a patient head CT angiography exam using the standard acquisition mode demonstrated the multi-energy capability of the PCD-CT system.

TIMING OPTIMIZATION OF HEAD AND NECK CT ANGIOGRAPHY VIA THE INVERSE PROBLEM ALGORITHM: in vivo SURVEY FOR 1001 PATIENTS IN 2020–2021

This study processed the recent in vivo survey results for over a thousand patients and optimized their neck and head CT angiography triggered timing (CTA-TT) via the inverse problem algorithm, which ensured the maximal ratio of both left and right arterial to upper sinuses (LRA/US). These results are instrumental in examining the ischemic stroke syndromes along the neck and head. These 1001 patients were randomly categorized into test surveyed (802 patients) and verification group (199 patients), then a six factors semi-empirical formula was constructed by the STATISTICA program. The six factors were assigned a patient’s biological data and preset of the CTA facility; namely Age, mean arterial pressure (MAP), heart rate (HR), contrast media dose (CMD), Pre (injected pressure of CMD), and body surface area (BSA). Each factor was normalized into dimensionless values and incorporated into the dataset matrix [Formula: see text] to analyze the coefficient matrix [Formula: see text]. The derived semi-empirical formula closely correlated with experimental data, according to the loss function [Formula: see text], correlation coefficient [Formula: see text], and variance of 0.8965. The formula verification for 199 more patients (verification group) yielded a correlation coefficient [Formula: see text]. Thus, it can be used for the CTA-TT estimation of patients without their preliminary tests, avoiding unnecessary irradiation. The estimated LRA/US was [Formula: see text] for the verification group in this study. A simplified three-factor formula, featuring only age, MAP, and BSA, was also proposed.

Evaluating the Routine Use of Head Computed Tomography Angiography in Blunt Cerebrovascular Trauma

The aim of this study was to evaluate a protocol change that mandated routine incorporation of head computed tomography angiography (CTA) for the work-up of suspected blunt cerebrovascular injury (BCVI) at an academic Level I trauma center. The BCVI screening guidelines at our institution changed in 2018 to include the addition of a head CTA for all patients receiving a neck CTA as part of our BCVI screening guidelines. We performed a retrospective chart review of patients between 2018 and 2019 who were 18 years or older and met screening criteria for BCVI based on our institutional guidelines. The head CTAs of this cohort were assessed for findings that could potentially alter the course of the patients' treatment. A total of 319 patients fit this criterion and had a head CTA as part of their trauma workup. Findings that could potentially alter a patient's clinical course were identified in 6.6% (n=21) of the head CTA's. These included decreased arterial perfusion (n=9), active bleeds (n=6), vessel occlusions (n=1), aneurysms (n=1), and vasospasms (n=2). Of these 21 patients, 8 had clinically significant findings that affected their course of management (2.5% of total sample). They also had a higher mortality rate and ISS compared to the rest of the cohort. In patients with clinically suspected BCVI, the addition of head CTA to the existing BCVI screening guideline identified clinically significant vascular abnormalities that affected management in 2.5% of cases.

Impact of H-Type Hypertension on Pericarotid Adipose Tissue and Plaque Characteristics Based on Computed Tomography (CT) Angiography: A Propensity Score Matching Study.

BackgroundWe analyzed the correlation among the inflammatory changes in pericarotid adipose tissue (PCAT), plaque characteristics, and H-type hypertension on CT angiography (CTA) and explored the utility of CTA in the prevention and treatment of carotid atherosclerosis.Material/MethodsA total of 135 patients who underwent head and neck CTA to investigate carotid artery atherosclerosis were retrospectively analyzed. The plaque characteristic parameters (plaque burden and remodeling index), PCAT attenuation value, and net enhancement value around the carotid artery, where the plaques were located, were recorded, and confounding factors were matched by propensity score analysis. A paired t test was used to compare the differences in fat tissue inflammatory changes and plaque characteristic parameters between the 2 groups, and logistic regression analysis was used to evaluate the relationship between plaque characteristics and the attenuation values and net enhancement values of PCAT. The correlation coefficient was calculated between type H hypertension and plaque risk grade.ResultsThe results of the experiment indicate that PCAT attenuation values and net enhancement values gradually increased as the degree of hypertension increased. Compared with those of patients in the normal Hcy group, these values increased more clearly in patients with high Hcy (HHcy) (r=0.641, P<0.001, r=0.581, P<0.001), although, regardless of whether the Hcy value increased, there were significant differences between the groups. However, this effect was more pronounced in patients with H-type hypertension. Logistic regression analysis of risk factors for carotid atherosclerotic plaque suggests that Hcy (OR=1.391, 95% CI 1.146–1.689, P=0.001), PCAT attenuation values (OR=1.212, 95% CI 1.074–1.367, P=0.002), and net enhancement values (OR=1.201, 95% CI 1.042–1.383, P=0.011) were independent risk factors for plaque vulnerability.ConclusionsOur results suggest that H-type hypertension is significantly associated with PCAT attenuation and net enhancement and that PCAT net enhancement values are useful in predicting plaque risk as attenuation.

Management of Mobile Thrombus With Distal Protection Devices During Carotid Artery Angioplasty: 2-Dimensional Operative Video.

Embolic protection devices (EPDs) have become a standard of care during internal carotid artery revascularization.1,2 This video is about a 57-yr-old-male who presented with a wake-up stroke with a left hemispheric syndrome. Head computed tomography angiography (CTA) revealed tandem occlusions of the proximal left internal carotid artery (ICA) and of the distal left middle cerebral artery (MCA) with an ASPECT (Alberta Stroke Program Early CTScore) score of 6. The patient underwent a cerebral angiogram and was treated with balloon angioplasty with a distal EPD and mechanical thrombectomy. The EPD became occluded with thrombus from the ICA and was retrieved through a 6-Fr Sofia (MicroVention) under continuous aspiration. Successful revascularization of the proximal ICA and distal MCA was achieved. No procedure-related complications occurred, and the patient's neurological exam improved. Tandem occlusions can occur in up to 15% of strokes. The optimal treatment can be controversial, but mechanical thrombectomy and ICA revascularization with a distal EPD appear to be safe and effective in selected patients.3 Consent was obtained for the procedure and for the video production.

Intracranial aneurysm is predicted by abdominal aortic calcification index: A retrospective case-control study

Background and aimsPatients with intracranial aneurysms (IA) have excess mortality for cardiovascular diseases, but little is known on whether atherosclerotic manifestations and IA coexist. We investigated abdominal aortic calcification index (ACI) association with unruptured and ruptured IAs. MethodsThis retrospective case-control study reviews all tertiary centers patients (n = 24,660) who had undergone head computed tomography angiography (CTA), magnetic resonance angiography (MRA) or digital subtraction angiography (DSA) for any reason between January 2003 and May 2018. Patients (n = 2020) with unruptured or ruptured IAs were identified, and patients with available abdominal CT were included. IA patients were matched by sex and age to controls (available abdomen CT, no IAs) in ratio of 1:3. ACI was measured from abdomen CT scans and patient records were reviewed. Results1720 patients (216 ruptured IA (rIA), 246 unruptured IA (UIA) and 1258 control) were included. Mean age was 62.9 ± 11.9 years and 58.2% were female. ACI (OR 1.02 per increment, 95%CI 1.01–1.03) and ACI>3 (OR 5.77, 95%CI 3.29–10.11) increased risk for rIA compared to matched controls. UIA patients' ACI was significantly higher but ACI did not increase odds for UIA compared to matched controls. History of coronary artery disease was less frequent in rIA patients. There was no calcification in aorta in 8.8% rIA and 13.6% UIA patients (matched controls 25.7% and 22.6% respectively, p < 0.01). ConclusionsAortic calcification is greater in rIA and UIA patients than matched controls. ACI increases risk for rIAs.

TAGUCHI-BASED OPTIMIZATION OF HEAD AND NECK CT ANGIOGRAPHY: IN-VIVO ENHANCED TRIGGERED TIMING FOR 600 PATIENTS

The Taguchi-based optimization of head and neck CT angiography (CTA) using in-vivo enhanced triggered timing for 600 patients was accomplished in this study. A total of 600 patients were categorized into three (test, verification, and implementation groups with 360, 120, and 120 patients, respectively). The patients in the test group were randomly assigned into 18 sub-groups according to Taguchi L[Formula: see text](2[Formula: see text]) orthogonal array for optimizing factor combinations of head and neck CTA. The signal-to-noise ratio was defined as a high LRA/US ratio (both left and right arterial pressure divided by upper sinuses’ one) and low stdev. The seven factors of CTA were: (A) left- or right-hand injection; (B) tube current, mA; (C) kilovoltage peak, kVp; (D) contrast media concentration; (E) FOV; (F) flow rate of contrast media; and (G) rotation time for one CTA loop. With the Taguchi unique organization, 18 sub-groups (each containing 20 patients’ real LRA/US ratios) could cover 1458 cases and provide the appropriate reliability. The optimal factor combination was identified as follows: (A) left-hand injection, (B) tube current of 280[Formula: see text]mA, (C) 100[Formula: see text]kVp, (D) contrast media concentration of 60%, (E) FOV of 250[Formula: see text]mm, (F) contrast media flow rate of 4.0[Formula: see text]ml/s, and (G) rotation time for one CTA loop of 0.9[Formula: see text]s. The optimal suggestion was validated in the verification group with 120 patients and applied to the implementation group with 120 patients. The successful factor combination is instrumental in defining a standard protocol for medical staff in deriving the maximal LRA/US value ([Formula: see text]) of head and neck CTA.

P-OT004. Recurrent direct carotid cavernous fistula after embolization, a case report

Introduction. Carotid cavernous fistula (CCF) is a rare case defined as an abnormal communication between carotid artery and cavernous sinus. Anatomically, CCF is classified as direct and indirect. Radiological imaging with Head CT scan and CT angiography (CTA) has an important role in CCF’s diagnosis and management. Endovascular embolization technique is one of the effective management for CCF. Results. A 16-year-old male complained left cephalgia and progressive visual lost on his left eye after endovascular embolization 3 years ago. Patient was diagnosed with CCF since he was 12. From physical examination, we found negative light perception on the left eye. From the former CT angiography, there was vascular malformation, suspected as multiple arteriovenous fistula at level carotid cavernous level urged bulbus oculi for 10 mm and also at left jugular external carotid. We performed the second head CT scan and CTA, with conclusion that there was vascular malformation which urged bulbus oculi for 17 mm. Patient was administered with clopidogrel 75 mg. Conclusion. Endovascular embolization as CCF’s management is effective but recurrence can happen.

Automated prediction of final infarct volume in patients with large-vessel occlusion acute ischemic stroke.

In patients with large-vessel occlusion (LVO) acute ischemic stroke (AIS), determinations of infarct size play a key role in the identification of candidates for endovascular stroke therapy (EVT). An accurate, automated method to quantify infarct at the time of presentation using widely available imaging modalities would improve screening for EVT. Here, the authors aimed to compare the performance of three measures of infarct core at presentation, including an automated method using machine learning. Patients with LVO AIS who underwent successful EVT at four comprehensive stroke centers were identified. Patients were included if they underwent concurrent noncontrast head CT (NCHCT), CT angiography (CTA), and CT perfusion (CTP) with Rapid imaging at the time of presentation, and MRI 24 to 48 hours after reperfusion. NCHCT scans were analyzed using the Alberta Stroke Program Early CT Score (ASPECTS) graded by neuroradiology or neurology expert readers. CTA source images were analyzed using a previously described machine learning model named DeepSymNet (DSN). Final infarct volume (FIV) was determined from diffusion-weighted MRI sequences using manual segmentation. The primary outcome was the performance of the three infarct core measurements (NCHCT-ASPECTS, CTA with DSN, and CTP-Rapid) to predict FIV, which was measured using area under the receiver operating characteristic (ROC) curve (AUC) analysis. Among 76 patients with LVO AIS who underwent EVT and met inclusion criteria, the median age was 67 years (IQR 54-76 years), 45% were female, and 37% were White. The median National Institutes of Health Stroke Scale score was 16 (IQR 12-22), and the median NCHCT-ASPECTS on presentation was 8 (IQR 7-8). The median time between when the patient was last known to be well and arrival was 156 minutes (IQR 73-303 minutes), and between NCHCT/CTA/CTP to groin puncture was 73 minutes (IQR 54-81 minutes). The AUC was obtained at three different cutoff points: 10 ml, 30 ml, and 50 ml FIV. At the 50-ml FIV cutoff, the AUC of ASPECTS was 0.74; of CTP core volume, 0.72; and of DSN, 0.82. Differences in AUCs for the three predictors were not significant for the three FIV cutoffs. In a cohort of patients with LVO AIS in whom reperfusion was achieved, determinations of infarct core at presentation by NCHCT-ASPECTS and a machine learning model analyzing CTA source images were equivalent to CTP in predicting FIV. These findings have suggested that the information to accurately predict infarct core in patients with LVO AIS was present in conventional imaging modalities (NCHCT and CTA) and accessible by machine learning methods.

内因性脳梗塞が先行した外傷症例に対し急性期再灌流療法を施行した1例(A case of revascularization therapy for acute ischemic stroke with a chief complaint of traumatic injury)

要旨 標準的な外傷診療では生理学的機能の管理および安定化を重視しており，神経学的所見は見逃されやすい。内因性脳梗塞が先行した外傷症例の診療について検討した。症例は78歳の男性，階段2階の踊り場から転落した。右共同偏視，右片麻痺，Glasgow coma scale（GCS）12の意識障害を認めた。外傷全身computed tomography（CT）で頭蓋内に占拠性病変は認めず，動脈優位相で左中大脳動脈の造影欠損を認めた。急性期脳梗塞と診断し，機械的血栓回収療法を行った。外傷機転を介在する内因性脳梗塞では，見逃しや治療介入に時間を要する可能性がある。病院前脳卒中スケールが症状検出に役立つ可能性があり，頭頂部の動脈優位相を含む造影CT検査で主幹動脈閉塞の検索が可能である。画像評価には熟練を要するため，3次元画像処理を行うとともに，適切に専門医へコンサルトし早期診断治療へつなげることが重要である。