CT Angiogram Research Articles

Stroke Imaging Performance Assessment at a Community-based Hospital

Introduction: An efficient stroke program plays a crucial role in timely diagnosis and management of acute stroke cases. Our hospital has endorsed performance targets for critical steps in the stroke activation and management pathway. This is a quality improvement initiative aimed to identify bottleneck events within the current code stroke pathway that led to delays in image acquisition/interpretation and challenge the achievement of set benchmark times. Methods: We constructed a process map outlining key steps in the code stroke pathway relevant to image acquisition and interpretation, aligning with the stroke target benchmark times. A total of 241 stroke cases documented between 1/1/2022 and 6/1/2022 were reviewed. Activity timestamp was utilized to calculate various time intervals and assess compliance with the specified benchmark times set by our institution’s stroke program. Results: Arrival to stroke activation was the most frequently missed benchmark (miss rate of 45.8%) with wide ranging arrival to code stroke activation time (mean of 18.9±22.2 minutes). The next frequently missed benchmarks were arrival to noncontrast head computed tomography (NCT) read time (miss rate of 25.4%), and arrival to first CT angiogram (CTA) slice acquisition time (miss rate of 21.1%), both set at under 45 minutes. The fourth frequently missed benchmark was observed in order to CTA read time, where 19.0% of cases missed the goal time of under 60 minutes; this benchmark encompasses the time interval between the first NCT slice to the subsequent first CTA slice, a variable time interval under the radiology department’s control that averaged 9.1±18.6 minutes. Conclusions: Although arrival to NCT read time and arrival to first CTA slice acquisition times were among the greatest missed time benchmarks, these were likely secondary to inconsistencies in arrival to code stroke activation time. One of the time intervals in the fourth frequently missed benchmark of order to CTA read time was under departmental control. Addressing and enhancing the consistency of this specific time interval could potentially contribute to an overall improvement in the time interval from ordering the CTA to the CTA being read.

Computed tomography angiography and coronary artery disease-reporting and data system and a 5-year prognostic major adverse cardiovascular and cerebral event outcome study in a symptomatic Southeast Asian population.

This study investigated the relationship between coronary artery disease-reporting and data system (CAD-RADS) for coronary computed tomography angiogram (CCTA) and major adverse cardiovascular and cerebral event (MACE) in a symptomatic Southeast Asian, Thai population over a 5-year period. A retrospective cohort study of Thai patients without known CAD who underwent CCTA for CAD symptoms. CCTA images and 5-year health data were reviewed for CAD-RADS and MACE. MACE consists of all-cause mortality, cardiovascular death, acute coronary syndrome, heart failure hospitalization, and stroke. In total 336 patients were evaluated. The median follow-up period was 6.4 years. The overall MACE incidence was 63 cases (18.8%). The MACE event rate was progressively increased with higher CAD-RADS categories; CAD-RADS 3 [hazard ratio (HR), 3.62; P = 0.015], CAD-RADS 4a (HR, 3.50; P = 0.024), CAD-RADS 4b & 5 (HR, 7.56; P = 0.001). The risk of MACE increased significantly in the moderate to severe CAD burden group (HR, 5.58; P = 0.01). Kaplan-Meier curve showed a significant rise in MACE with higher CAD-RADS categories ( P = 0.01). CAD-RADS classification has a significant prognostic value in Southeast Asian, Thai population with cardiac symptoms.

Popliteal artery aneurysm treated with endovascular technique and new device: case report and literature review

In this paper, we aimed to report an alternative endovascular treatment in a patient with an isolated popliteal artery aneurysm. A 69 year-old male patient, with hypertension and post-operative of gastric bypass surgery for obesity, was admitted with right limb pain, mainly in the calf, associated with a weakness and difficulty walking. The patient was submitted to a duplex ultrasound, that suggested a popliteal artery aneurysm, with 3,8 cm diameter, confirmed with CT angiogram. Furthermore, the patient had no proper saphenous vein diameter for a open surgery bypass evaluated by a Doppler ultrasound. Then, the patient was scheduled to undergo endovascular treatment of the popliteal artery aneurysm with two covered self-expandable 8x100 and 10x75 Merit Wrapsodyâ. The patient was discharged from the hospital two days after the surgery with no complications, palpable pedal pulses taking Rivaroxaban 20mg and Clopidogrel 75mg daily. At year follow-up the patient was asymptomatic and duplex showed patent stent without evidence of endoleak.

Including isolated aphasia improves sensitivity and negative predicative value for large vessel occlusion screening

BackgroundLarge Vessel Occlusion (LVO) screening tools provide objective assessments to guide diagnostic decisions during acute stroke activations. The Stroke VAN screening tool includes weakness, vision, aphasia, and neglect; however, only screens positive if weakness is present regardless of presence of other symptoms including isolated aphasia. The purpose of this project was to evaluate wAve, a modified Stroke VAN screening tool. WAve includes components of VAN with emphasis on isolated aphasia. MethodsWe conducted a retrospective cohort study on 376 persons who presented with stroke symptoms within 24 h of last known well (LKW) to the Emergency Department of an urban comprehensive stroke center in north central Texas between July 2019 and January 2020. Comparison of VAN and wAve predictive values was calculated using Chi square analysis. Sensitivity and specificity was checked by using MedCalc software. Data from the electronic medical record was obtained for analysis including a documented wAve score and a calculated VAN score. Results of CT angiogram diagnostic testing was used to determine congruence of screening results with evidence of LVO. Power analysis described by Hajian- Tilaki was used to estimate study size. ResultsResults included 192 positive wAve screens and 184 negative wAve screens compared to 152 positive VAN screens and 224 negative VAN screens. The sensitivities for wAve and VAN were 89 % and 80 % respectively. Negative predictive values for wAve and VAN were 97 % and 95 % respectively. In isolated aphasic person, one of eight presented with a LVO and received intervention. ConclusionThe team discovered more LVOs were identified with wAve than VAN in persons exhibiting isolated aphasia symptoms. Larger studies are needed to understand the role isolated aphasia plays in LVO detection.

Management of Type A Aortic Dissection in the Emergency Department: A Comprehensive Case Report

This case report elucidates the presentation and management of a 54-year-old man with type A aortic dissection (TAAD) in the emergency department. The patient, a known diabetic with uncontrolled hypertension and a history of heavy smoking, presented with severe central chest pain radiating to the back, accompanied by diaphoresis. Clinical evaluation revealed tachycardia and normotension. An immediate computed tomography angiogram confirmed the diagnosis of TAAD. The patient received timely medical intervention with intravenous beta-blockers and was prepared for a surgical consultation. This report underscores the critical importance of rapid diagnosis, effective blood pressure control, and multidisciplinary collaboration in the management of TAAD in the emergency setting, emphasizing contemporary evidence-based practices. While the article omits details on operative procedures, it notes that the patient was discharged in stable condition postsurgery, and at the 3-month follow-up, he is progressing well.

Postdissection aortic aneurysm sac enlargement after fenestrated and branched endovascular aortic aneurysm repair

ObjectivesAneurysm sac changes after fenestrated-branched endovascular aneurysm repair (FBEVAR) for postdissection thoracoabdominal aortic aneurysms (PD-TAAs) are poorly understood. Partial thrombosis of the false lumen and endoleaks may impair sac regression. To characterize sac changes after FBEVAR for PD-TAAs, this study examined midterm results and predictors for sac enlargement. MethodsFBEVARs performed for PD-TAAs in 10 physician-sponsored investigational device exemption studies from 2008 to 2023 were analyzed. The maximum aortic aneurysm diameter was compared between the 30-day computed tomography angiogram and follow-up imaging studies. Aneurysm sac enlargement was defined as an increase in diameter of ≥5 mm. Kaplan-Meier curves and Cox regression were used to evaluate sac enlargement and midterm FBEVAR outcomes. ResultsAmong 3296 FBEVARs, 290 patients (72.4% male; median age, 68.4 years) were treated for PD-TAAs. Most aneurysms treated were extent II (72%) and III (12%). Mean aneurysm diameter was 66.5 ± 11.2 mm. Mortality at 30 days was 1.4%. At a mean follow-up of 2.9 ± 1.9 years, at least one follow-up imaging study revealed sac enlargement in 43 patients (15%), sac regression in 115 patients (40%), and neither enlargement nor regression in 137 (47%); 5 (2%) demonstrated both expansion and regression during follow-up. Freedom from aneurysm sac enlargement was 93%, 82%, and 80% at 1, 3, and 5 years, respectively. Overall, endoleaks were detected in 27 patients (63%) with sac enlargement and 143 patients (58%) without enlargement (P = .54). Sac enlargement was significantly more frequent among older patients (mean age at the index procedure, 70.2 ± 8.9 years vs 66.5 ± 11 years; P = .04) and those with type II endoleaks at 1 year (74% vs 52%; P = .031). Cox regression revealed age >70 years at baseline (hazard ratio [HR], 2.146; 95% confidence interval [CI], 1.167-3.944; P = .010) and presence of type II endoleak at 1 year (HR, 2.25; 95% CI, 1.07-4.79; P = .032) were independent predictors of sac enlargement. Patient survival was 92%, 81%, and 68% at 1, 3, and 5 years, respectively. Cumulative target vessel instability was 7%, and aneurysm-related mortality was 2% at 5 years. At least 42% of patients required secondary interventions. Sac enlargement did not affect patient survival. ConclusionsAneurysm sac enlargement occurs in 15% of patients after FBEVAR for PD-TAAs. Elderly patients (>70 years at baseline) and those with type II endoleaks at 1 year may need closer monitoring and secondary interventions to prevent sac enlargement. Despite sac enlargement in some patients, aneurysm-related mortality at 5 years remains low and overall survival was not associated with sac enlargement.

Incidental findings in 1000 consecutive CT angiograms for DIEP flap breast reconstruction

Incidental findings in 1000 consecutive CT angiograms for DIEP flap breast reconstruction

Editor's Choice – Sex Related Anatomical Differences in Patients With Aortic Arch Pathology and Their Impact on the Feasibility of Double and Triple Branched Endografts

To evaluate sex based differences in ascending aorta and arch anatomy in patients with underlying proximal aortic disease and to evaluate their impact on feasibility for total endovascular repair with custom made, branched arch devices. This was a retrospective cross sectional review of all patients undergoing open and or total endovascular arch repair due to distal ascending aorta and or aortic arch pathologies in a single high volume aortic centre between 2012 and 2022. Anatomical ascending aorta and aortic arch parameters were analysed on a flow centreline on a dedicated 3D workstation. Sex related differences of the ascending aorta, aortic arch, and supra-aortic vessels were evaluated. Subsequently, four endovascular devices were assessed for feasibility: double and triple branched devices both for the Zenith (Cook Medical) and Relay (Terumo Aortic) platforms, first in accordance with the instructions for use and then considering the possibility of adjunctive cervical debranching. The primary endpoints were sex specific differences in aortic anatomy, while secondary endpoints included sex based feasibility of branched endograft devices. During the study period, 395 patients underwent total aortic arch repair, of whom 152 (51 female, 33.5%) had high quality computed tomography angiograms available and were included in the study. Female patients had a shorter proximal landing zone than males (22 mm vs. 47 mm; p < .001). Left subclavian artery dissection was more frequent in men (24.8% vs. 3.9%; p < .001). Other anatomical parameters showed a similar distribution between sexes. Female patients presented a lower feasibility for double branched devices (35.3% vs. 58.4%; p= .015) as well as a tendency for lower feasibility rates for triple branched devices (31.4% vs. 47.5%; p= .081). Although most ascending aortic and arch parameters showed similar trends in both sexes, the availability of a suitable proximal landing zone was lower in female patients. Consequently, female patients had lower feasibility rates for double arch branched endografts and, to lesser extent, for triple arch branched endografts.

The vertical topography of the carotid bifurcation – original study and review

PurposeThe vertical level of carotid bifurcation (CB) is commonly indicated at the superior margin of the thyroid cartilage. Few studies observed the CB vertical topography. It was aimed at studying the vertical location of the CB as referred to vertebral and anterior cervical landmarks.MethodsAn archived lot of 147 computed tomography angiograms was documented for the vertical level of CB referred to vertebral and anterior cervical landmarks. The topography of the CB in relation to anterior landmarks was classified into seven types: (1) at the superior margin of the thyroid cartilage; (2) between the hyoid and the thyroid cartilage; (3) at the hyoid level; (4) between the hyoid and mandible; (5) subgonial or supragonial CB; (6) lower cervical level; (7) intrathoracic.ResultsThe most common locations of CB were at C3 (27.21%), C3/C4 (26.19%) and C4 (25.51%). Bilateral symmetry of CB was found in 51.7%, except for C2 and C5/C6. Type 7 was not found, type 3 occurred in 39.12%, type 2 in 24.49%, type 1 in 13.95%, type 4 in 13.61%, type 5 in 6.12%, and type 6 in 2.72% (294 CBs). Bilateral symmetry of anterior types was found in 59.86%. Statistically significant correlations were found between sex and both left and right types and vertebral levels of CB.ConclusionsThe vertical topography of the CB is highly variable and has sex-related specificity. This detail should be included in the teaching of anatomy. Surgeons and interventionists should better document the carotid anatomy on a case-by-case basis.

Investigating the Role of Serum Hepcidin and Interleukin-6 in Non-Anemic Women with Acute Ischemic Stroke

Background: Hepcidin (HP) is an important regulator of iron homeostasis. Iron status and IL-6 have been shown to regulate the expression of HP. Serum iron (SI), HP, and IL-6 have a highly significant role in inflammation since inflammation elevates the levels of HP for expressing the ischemic condition. The present study was carried out to investigate the impact of an interactive association between HP, SI, and IL-6 in non-anemic women with acute ischemic stroke (AIS). Methods and Results: The present case-control, descriptive study comprised 25 non-anemic women with AIS and 25 healthy non-anemic women controls. The age range of AIS and control subjects was 50 to 54 years. Non-anemic AIS women within 8 hours after AIS onset (AIS&lt;8 hrs) and 72 hours after onset of AIS (AIS-72 hours) were examined. The patients underwent assessment of traditional risk factors, physical examination, CBC, blood biochemistry test, 12-lead ECG, CT scans, MRI, CT or MR angiogram, carotid ultrasound of the arteries, transcranial doppler ultrasound, and EEG. Office blood pressure was measured using a mercury sphygmomanometer. Significantly increased values were obtained for systolic blood pressure and diastolic blood pressure in AIS women, compared to the control subjects: 137.44±12.35 vs. 130.88±7.30 mmHg (P=0.0267) and 86.72± 8.48 vs. 81.80± 5.42 mmHg (P=0.0183), respectively. Serum CRP and LDL-C levels in AIS were significantly higher than in healthy control women (P&lt;0.0001). A significant increase in serum HP, SI, and IL-6 for AIS&lt;8 hrs was found, compared to AIS-72 hrs (P&lt;0.001 in all cases). Comparison for AIS&lt;8 hrs vs. controls showed a highly significant increase in serum HP, SI, and IL-6 for AIS&lt;8 hrs (P&lt;0.001 in all cases). On the other hand, AIS-72 hrs vs. controls indicated a significant increase in SI (P=0.0028) and IL-6 (P=0.0065) but a non-significant increase in serum HP (P&gt;0.05) in AIS-72 hrs. Linear regression expressed a high strength of the relationship between serum HP and SI for AIS&lt;8 hrs (R2=0.82, P&lt;0.0001) and AIS-72 hrs (R2=0.73, P&lt;0.0001), but a negligible linear association for controls (R2=0.01, P=0.5990). There was a high relationship between HP and IL-6 for AIS&lt;8 hrs (R2=0.67, P&lt;0.0001) and AIS-72 hrs (R2=0.67, P&lt;0.0001), but a small linear association for controls (R2=0.28, P=0.0063). The R2 value of 0.47 (P&lt;0.0002) and 0.42 (P&lt;0.0004) was found between SI and IL-6 for AIS&lt;8 hrs and AIS-72 hrs, and a negligible linear association (R2=0.006, P=0.7250) for controls. Conclusion: The present study provides evidence of the association of AIS in non-anemic women with increased hepcidin. The interactive pathophysiological role of HP, IL-6, and SI in non-anemic women with AIS has also been shown.

MSO-GP: 3-D segmentation of large and complex conjoined tree structures

Robust segmentation of large and complex conjoined tree structures in 3-D is a major challenge in computer vision. This is particularly true in computational biology, where we often encounter large data structures in size, but few in number, which poses a hard problem for learning algorithms. We show that merging multiscale opening with geodesic path propagation, can shed new light on this classic machine vision challenge, while circumventing the learning issue by developing an unsupervised visual geometry approach (digital topology/morphometry). The novelty of the proposed MSO-GP method comes from the geodesic path propagation being guided by a skeletonization of the conjoined structure that helps to achieve robust segmentation results in a particularly challenging task in this area, that of artery-vein separation from non-contrast pulmonary computed tomography angiograms. This is an important first step in measuring vascular geometry to then diagnose pulmonary diseases and to develop image-based phenotypes. We first present proof-of-concept results on synthetic data, and then verify the performance on pig lung and human lung data with less segmentation time and user intervention needs than those of the competing methods.

Repair of inflammatory celiac artery aneurysm presenting with insidious onset of abdominal pain: A case report

BackgroundVisceral artery aneurysms (VAAs) are rare but potentially devastating given the high mortality associated with rupture. Current Society of Vascular Surgery guidelines recommend repair of these at 2.5 cm. Surgical intervention includes endovascular embolization and/or stenting versus open revascularization. This case presents a patient with a large celiac artery aneurysm (CAA) who underwent open ligation of the celiac artery at the origin. Splenectomy was performed given the need for ligation of the splenic artery. He had a replaced right hepatic artery from the SMA; thus, no revascularization was needed. Ultimately, the aneurysm was found to be inflammatory in etiology. Case reportA 41-year old male with history of seizure disorder, smoking, and newly diagnosed hypertension presented with abdominal pain for six months. His-laboratory work was significant for a leukocytosis of 17, 740, mildly elevated C- Reactive Protein (CRP) at 1.63, and normal erythrocyte sedimentation rate (ESR). CT angiogram revealed a 5.2 × 4.2 cm celiac artery aneurysm with stranding. Given its appearance and concern for infection, he underwent emergent laparotomy and ligation. Blood cultures and intraoperative tissues revealed no microorganism growth. Pathology was remarkable only for periarterial abscess with acute and chronic inflammation and focal tissue necrosis, compatible with aneurysm. ConclusionThis case report presents a rare inflammatory CAA, which presented with six months of abdominal pain, and its subsequent management with open intervention. In this case, his vessel anatomy was favorable for open repair with ligation of the celiac axis due to the presence of a replaced right hepatic artery. This also highlights the importance of anatomic vessel variants when making surgical decisions.

Volumetric Analysis of a Novel Chimeric Gracilis and Profunda Artery Perforator Flap.

The presence of a chimeric gracilis and profunda artery perforator (PAP) flap with a common arterial pedicle has been demonstrated on computed tomography angiography in up to 59% of patients and confirmed in a cadaveric model. Already utilized for head and neck reconstruction by Heredero et al, this novel flap could provide more volume than either flap alone which is advantageous, particularly in patients with sizable defects. The purpose of this study was to determine the average tissue volume that can be utilized from this chimeric flap. CT Angiogram imaging studies exhibiting chimeric flap anatomy were reviewed over a 7-year period at a single institution utilizing Visage Version 7.1, a radiology picture archiving and communication system. This software was used to trace the flap pedicles and to capture estimated soft tissue volumes of each respective flap. A total of 31 patients, consisting of 52 lower extremity gracilis and PAP chimeric flaps, underwent tissue volume analysis. The average total volume of soft tissue supplied by the gracilis flap was found to be 70.21 cm3 (standard deviation [SD] = 26.99). The average volume of the PAP flap was 31.73 cm3 (SD = 26.12). The average total volume captured by the chimeric gracilis and PAP flap was 101.94 cm3 (SD = 62.40). The potential soft tissue volume that can be harvested from a chimeric gracilis and PAP flap is significantly greater than solitary gracilis or PAP flaps. This chimeric flap may serve as a viable and advantageous reconstructive option for patients requiring large volume soft tissue coverage, particularly if other sizable options are not available.

Uncommon presentations of type A quadricuspid aortic valve in the Septuagenarian

BackgroundQuadricuspid aortic valve (QAV) is a rare congenital anomaly characterized by the presence of four cusps instead of the usual three. It is estimated to occur in less than 0.05% of the population, with Type A (four equal-sized leaflets) accounting for roughly 30% of QAV subtypes. Based on limited clinical series, the usual presentation is progressive aortic valve regurgitation (AR) with symptoms occurring in the fourth to sixth decade of life. Severe aortic valve stenosis (AS) and acute AR are very uncommon.Case presentationWe describe two cases of Type A QAV in patients who remained asymptomatic until their seventies with very uncommon presentations: one with severe AS and one with acute, severe AR and flail leaflet. In Case A, a 72-year-old patient with history of moderate AS presents to clinic with progressive exertional dyspnea. During work-up for transcatheter vs. surgical replacement pre-operative computed tomography angiogram (CTA) reveals a quadricuspid aortic valve with severe AS, and the patient undergoes surgical aortic valve replacement. Pre-discharge transthoracic echocardiography (TTE) shows good prosthetic valve function with no gradient or regurgitation. In Case B, a 76-year-old patient is intubated upon arrival to the hospital for acute desaturation, found to have wide open AR on catheterization, and transferred for emergent intervention. Intraoperative TEE reveals QAV with flail leaflet and severe AR. Repair is considered but deferred ultimately due to emergent nature. Post-operative TTE demonstrates good prosthetic valve function with no regurgitation and normal biventricular function.ConclusionsQAV can present as progressive severe AS and acute AR, with symptoms first occurring in the seventh decade of life. The optimal treatment for QAV remains uncertain. Although aortic valve repair or transcatheter option may be feasible in some patients, aortic valve replacement remains a tenable option.

P.107 How often does digital subtraction angiography change management in CT angiogram negative subarachnoid hemorrhages?

Background: Subarachnoid hemorrhages (SAH) are emergencies that require expedient workup. While Aneurysms and vascular malformations are a common cause, a subset of cases may lack detectable structural causes. If a CT angiogram (CTA) is negative, the more invasive Digital Subtraction Angiogram (DSA) is used for diagnosis. It is unclear how often DSA alters treatment for CTA negative SAHs. Methods: A retrospective review of SAH patients from our institution (Vancouver General Hospital) with a negative CTA with subsequent DSA in the past 25 years. Results: Our preliminary analysis included 233 patients. The median age was 55. 105 (45%) were female, and 128 (55%) were male. The average length of hospitalization was 9.6 days, and 226 (97%) were discharged alive. The median number of CTAs and DSAs administered were 2 and 1 respectively. In 12 (5%) cases, DSA detected an abnormality not seen on CTA, which led to endovascular or open surgery treatment in 5 (2%) cases. 5 DSA procedures led to complications including transient neurologic changes and ischemia. Conclusions: In SAH patients with CTA negative scans, additional DSA testing identified actionable pathology in only a small minority of cases. Clinicians must weigh the benefit of DSAs in these cases.

Fungal carotiditis with aneurysm - a rare complication of mucormycosis: presentation and management

During the COVID-19 pandemic, cases of mucormycosis (ROCM) had increased drastically, especially in the second wave. Most of these cases involved the paranasal sinuses, orbit and occasionally brain. This case report presents a rare case of mucormycosis complicated with a mycotic aneurysm of the petrous part of the internal carotid artery (ICA). A 43-year-old man presented with left-sided facial weakness for which high resolution computed tomography scan of the Temporal bones was done. A scrutiny of the computed tomography temporal bone showed evidence of osteomyelitis extending to the petrous apex around the foramen Lacerum. Computed tomography and magnetic resonance imaging of the paranasal sinus done later confirmed the diagnosis of mucormycosis. The patient underwent endoscopic surgical debridement of the nose and sinuses, with post-operative amphotericin B. After 3 weeks, the patient presented with bouts of profuse nasal bleed. Computed tomography angiogram showed an aneurysm in the petrous segment of the ICA suggestive of mycotic carotiditis complicated from mucormycosis spread along the skull base. It was successfully managed neurosurgically by a bypass shunting procedure. Mucormycosis is a disease that typically has an aggressive and startling fatality rate. ICA aneurysm is an uncommon occurrence in mucormycosis. Subjects with ROCM should be examined for brain and vascular involvement. Computed tomography angiogram should be performed as soon as possible if the skull base is involved in the ICA area. Morbidity and mortality can often be reduced by early diagnosis and interventions by a multidisciplinary team.

Neurovascular Imaging with Ultra-High-Resolution Photon-Counting CT: Preliminary Findings on Image-Quality Evaluation.

The first-generation photon-counting detector CT was recently introduced into clinical practice and represents a promising innovation in high-resolution CT imaging. The purpose of this study was to assess the image quality of ultra-high-resolution photon-counting detector CT compared with energy-integrating detector CT and to explore different reconstruction kernel sharpness levels for the evaluation of intracranial aneurysms. Ten patients with intracranial saccular aneurysms who had previously undergone conventional energy-integrating detector CT were prospectively enrolled. CT angiograms were acquired on a clinical dual-source photon-counting detector CT in ultra-high-resolution mode and reconstructed with 4 vascular kernels (Bv36, Bv40, Bv44, Bv48). Quantitative and qualitative image-quality parameters of the intracranial arteries were evaluated. For the quantitative analysis (image noise, SNR, contrast-to-noise ratio), ROIs were manually placed at standard anatomic intracranial and extracranial locations by 1 author. In addition, vessel border sharpness was evaluated quantitatively. For the qualitative analysis, 3 blinded neuroradiologists rated photon-counting detector CT and energy-integrating detector CT image quality for the evaluation of the intracranial vessels (ie, the aneurysms and 9 standard vascular branching locations) on a 5-point Likert-type scale. Additionally, readers independently selected their preferred kernel among the 4 kernels evaluated on photon-counting detector CT. In terms of quantitative image quality, Bv48, the sharpest kernel, yielded increased image noise and decreased SNR and contrast-to-noise ratio parameters compared with Bv36, the smoothest kernel. Compared with energy-integrating detector CT, the Bv48 kernel offered better quantitative image quality for the evaluation of small intracranial vessels (P < .001). Image-quality ratings of the Bv48 were superior to those of the energy-integrating detector CT and not significantly different from ratings of the B44 reconstruction kernel. When comparing side by side all 4 photon-counting detector reconstruction kernels, readers selected the B48 kernel as the best to visualize the aneurysms in 80% of cases. Ultra-high-resolution photon-counting detector CT provides improved image quality for neurovascular imaging. Although the less sharp kernels provided superior SNR and contrast-to-noise ratio, the sharpest kernels delivered the best subjective image quality on photon-counting detector CT for the evaluation of intracranial aneurysms.

A Randomized Controlled Trial of Tenecteplase Versus Standard of Care for Minor Ischemic Stroke with Proven Occlusion (TEMPO-2): Rational and design of a multicenter, randomized open-label clinical trial.

Almost half of acute ischemic stroke patients present with mild symptoms and there are large practice variations in their treatment globally. Individuals with an intracranial occlusion who present with minor stroke are at an increased risk of early neurological deterioration and poor outcomes. Individual patient data meta-analysis in the subgroup of patients with minor deficits showed benefit of alteplase in improving outcomes; however, this benefit has not been seen with intravenous alteplase in published randomized trials. TEMPO-2 (A Randomized Controlled Trial of Tenecteplase Versus Standard of Care for Minor Ischemic Stroke With Proven Occlusion) is a prospective, open label with blinded outcome assessment, randomized controlled trial, designed to test the superiority of intravenous tenecteplase (0.25 mg/kg) over nonthrombolytic standard of care, with an estimated sample size of 1274 patients. Adult patients presenting with acute ischemic stroke with the National Institutes of Health Stroke Scale (NIHSS) ⩽ 5 and visible arterial occlusion or perfusion deficit within 12 h of onset are randomized to receive either tenecteplase (0.25 mg/kg) or standard of care. The primary outcome is return to baseline neurological functioning, measured by the modified Rankin scale (mRS) at 90 days. Safety outcomes include death and symptomatic hemorrhage (intra or extra-cranial). Other secondary outcomes include mRS 0-1, mRS 0-2, ordinal shift analysis of the mRS, partial, and full recanalization on follow-up computed tomography angiogram. Results of this trial will aid in determining whether there is benefit of using tenecteplase (0.25 mg/kg) in treating patients presenting with minor stroke who are at high risk of developing poor outcomes due to presence of an intracranial occlusion. Data will be available upon reasonable request.

First‐Line Treatment of Symptomatic Subocclusive Large‐Vessel Stroke: Results of a Nationwide StrokeNet Survey

Background Limited evidence is available for the treatment of acute symptomatic subocclusive lesions in ischemic stroke. We sought to identify current treatment patterns of stroke teams at academic health centers. Methods We conducted an email survey of the National Institutes of Health StrokeNet regional coordinating centers (RCCs). Each RCC principal investigator was asked to nominate a local stroke interventionalist, or a neurologist if the RCC principal investigator was an interventionalist, most aligned with the typical practice pattern of the RCC's lead hospital, to receive a survey. The survey consisted of a clinical vignette and displayed a subocclusive lesion in the left middle cerebral artery on computed tomography angiogram followed by subsequent scenarios, revising only 1 historical, clinical, or radiographic variable at a time. Participants were asked to select initial management for each scenario. Results were reviewed and analyzed by stroke‐trained physicians. Results Responses were received from 42 (77.8%) of 54 surveyed individuals, representing 25 (92.6%) of 27 RCCs nationwide, including 25 (59.5%) interventionalists. The majority (76.2%) of respondents treated the patient in the primary clinical vignette with mechanical thrombectomy. Among all 6 clinical scenarios, respondents chose mechanical thrombectomy with or without medical management as first‐line treatment for 4 (67%) vignettes. Exceptions were low National Institutes of Health Stroke Scale score and known ipsilateral stenosis, where respondents chose medical management as first‐line treatment. Conclusion Despite limited evidence to support mechanical thrombectomy versus other treatment strategies, the majority of StrokeNet RCC respondents would use mechanical thrombectomy with or without medical therapy to treat acute ischemic stroke due to intracranial subocclusive lesions.

3D Characterization of the Aortic Valve and Aortic Arch in Bicuspid Aortic Valve Patients.

Patients with bicuspid aortic valve (BAV) commonly have associated aortic stenosis and aortopathy. The geometry of the aortic arch and BAV is not well defined quantitatively, which makes clinical classifications subjective or reliant on limited 2D measurements. The goal of this study was to characterize the 3D geometry of the aortic arch and BAV using objective and quantitative techniques. Pre-TAVR computed tomography angiogram (CTA) in patients with BAV and aortic stenosis (AS)were analyzed (n = 59) by assessing valve commissural angle, presence of a fused region, percent of fusion, and calcium volume. The ascending aorta and aortic arch were reconstructed from patient-specific imaging segmentation to generate a centerline and calculate maximum curvature and maximum area change for the ascending aorta and the descending aorta. Aortic valve commissural angle signified a bimodal distribution suggesting tricuspid-like (≤150°, 52.5% of patients) and bicuspid-like (>150°, 47.5%) morphologies. Tricuspid like was further classified by partial (10.2%) or full (42.4%) fusion, and bicuspid like was further classified into valves with fused region (27.1%) or no fused region (20.3%). Qualitatively, the aortic arch was found to have complex patient-specific variations in its 3D shape with some showing extreme diameter changes and kinks. Quantitatively, subgroups were established using maximum curvature threshold of 0.04 and maximum area change of 30% independently for the ascending and descending aorta. These findings provide insight into the geometric structure of the aortic valve and aortic arch in patients presenting with BAV and AS where 3D characterization allows for quantitative classification of these complex anatomic structures.