Brain Computed Tomography Angiography Research Articles

Transient Ischemic Attack After Scorpion Sting: A Case Report

Aim: Stroke is a rare complication that occurs in addition to life-threatening respiratory and cardiovascular symptoms as a result of a scorpion sting. In this case, we presented a patient who had a transient ischemic attack that developed due to a scorpion sting, which had not been presented in the literature before.
 
 Case: Our case was a 69-year-old male patient who felt pain in his left leg when he woke up in the morning. Weakness and speech disorder developed in the left arm and leg, developed approximately 1.5 hours after this pain. In the first examination of the patient, dysarthria, facial asymmetry, and loss of strength on the left side were detected. No significant pathology was observed in magnetic resonance imaging, brain computed tomography, and brain computed tomography angiography. In the physical examination, a dead scorpion has been found among the clothes, and mild redness and swelling at the level of the left ankle were observed. All neurological deficits in the patient resolved completely after 3 hours. Since no risk factor was detected in the examinations, it was thought that there was a transient ischemic attack due to scorpion venom.
 
 Conclusion: While investigating the etiology of transient ischemic attack, careful physical examination besides neurological examination and anamnesis is very important for differential diagnosis of rare causes.

The value of a deep learning image reconstruction algorithm in whole-brain computed tomography perfusion in patients with acute ischemic stroke.

Computed tomography perfusion (CTP) and computed tomography angiography (CTA) are valuable tools for diagnosing acute ischemic stroke (AIS). It is essential to obtain high-quality CTP and CTA images in short time. This study aimed to evaluate the image quality and diagnostic performance of brain CTP and CTA images generated from CTP reconstructed by a deep learning image reconstruction (DLIR) algorithm on patients with AIS. The study prospectively enrolled 54 patients with suspected AIS undergoing non-contrast CT and CTP within 24 hours. CTP datasets were reconstructed with three levels of adaptive statistical iterative reconstruction-Veo algorithm [ASIR-V 0% with filtered back projection (FBP), ASIR-V 40%, and ASIR-V 80%] and three levels of DLIR, including low (DLIR-L), medium (DLIR-M), and high (DLIR-H). CTA images were generated using the CTP datasets at the peak arterial phase. Objective parameters including signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and noise reduction rate. Subjective evaluation was assessed according to Abels scoring system. Perfusion parameters and detection accuracy for infarction core lesions were evaluated. The objective and subjective image quality of CTA images were also evaluated. All reconstructions produced similar CT values (P>0.05). With the increase of ASIR-V and DLIR reconstruction strength, image noise decreased, while SNR and CNR increased for CTP images, especially in white matter. DLIR-H, DLIR-M, and ASIR-V80% yielded higher subjective scores than did ASIR-V40% and FBP. DLIR-H provided the highest noise reduction rate and detection accuracy. No significant difference was found in conventional parameters, the volume of infarct core, or ischemic penumbra among the 6 groups (P>0.05). The objective evaluation of reconstructed CTA images was comparable in DLIR-H, DLIR-M, and ASIR-V80% (P>0.05). The subjective scores of the DLIR-H and DLIR-M images were higher than those of the other groups, especially ASIR-V40% and FBP (P<0.05). Compared with FBP and ASIR-V40%, DLIR-H, DLIR-M, and ASIR-V80% improved the overall image quality of CTP and CTA images to varying degrees. Furthermore, DLIR-H and DLIR-M showed the best performance. DLIR-H is the best choice in diagnosing AIS with improved detection accuracy for cerebral infarction. Reconstructing CTA images using CTP datasets could reduce contrast agent and radiation dose.

Use of Thick Maximum‐Intensity Projection Brain Computed Tomography Angiography for Evaluation of Baseline Collateral Status Improves Interrater Agreement

Background In acute ischemic stroke caused by large‐vessel occlusion, tissue viability is dependent on the blood supply from leptomeningeal collaterals until reperfusion is achieved. Rapid and accurate evaluation of baseline collateral status is a key marker of eligibility for endovascular therapy but can be challenging to interpret using source images of the computed tomography angiography (SI‐CTA). Our objective was to assess whether the use of thick maximum‐intensity projection computed tomography angiography (MIP‐CTA) improves interrater agreement for evaluation of baseline collaterals status between stroke trainees and an expert stroke neurologist. Methods An expert stroke neurologist and 2 stroke trainees independently reviewed images from 40 brain CTA scans with anterior circulation large‐vessel occlusion and assessed collateral status using the Tan collateral scoring system using SI‐CTA in the first reading and then using MIP‐CTA in the second reading. We calculated interrater agreement and recorded the total time needed in each reading. Results Interrater agreement was fair between the 2 stroke fellows and stroke expert when using SI‐CTA (κ=0.45 with 52.5% agreement). After using MIP‐CTA, interrater agreement improved to moderate (κ=0.69 with 70% agreement). The median reading time was 1.89 minutes per scan using SI‐CTA and 1.00 minute per scan using MIP‐CTA ( P &lt;0.0001). Conclusions We show that using MIP‐CTA, when compared with SI‐CTA, shortens interpretation time and improves interrater agreement between stroke trainees and a stroke imaging expert for the evaluation of baseline collaterals in patients presenting with anterior circulation large‐vessel occlusion.

Abstract 256: Proposal of multimodal CT‐based scoring system in prediction of hemorrhagic transformation in acute ischemic stroke

Introduction The routinely used computed tomography (CT)‐based workup in the setting of acute ischemic stroke (AIS) includes non‐contrast brain CT, CT angiography (CTA), and CT perfusion. Several CT, CTA, CTP‐based radiological biomarkers of hemorrhagic transformation (HT) were reported. To assess the predictive value of the combined multimodal CT parameters for HT after AIS and proposal of predictive scoring scale. Methods The source images of the NCCT, CTA and CTP of 282 AIS patients involving the anterior circulation (HT = 91, non‐HT = 191) were retrospectively reviewed and the following biomarkers were recorded and analyzed: Early subtle ischemic signs, hyperdense middle cerebral artery sign (HMCAS) and Alberta Stroke Program Early CT Score (ASPECTS) &lt; 7 in NCCT, large‐vessel occlusion (LVO), clot burden score (CBS) &lt; 6, large‐vessel occlusion, poor collateral score (CS) and Tmax &gt; 6 s ≥ 56.5 ml. A scoring system to predict HT based on these biomarkers was developed. Each biomarker counts for a single point with the total score ranging from 0 to 7. Results All the aforementioned multimodal CT biomarkers and the selected cut offs were significantly associated with higher HT risk. The calculated scores were statistically significant different between the HT and the non‐HT groups with AUC 0.761 (95% CI 0.703–0.819, P &lt; 0.0000001). Rates of HT were approximately five times higher in patients with score ≥ 3. Conclusion Multimodal CT‐based scoring system may provide highly reliable predictive model of hemorrhagic transformation in acute ischemic stroke.

Length of Survival, Outcome, and Potential Predictors in Poor-Grade Aneurysmal Subarachnoid Hemorrhage Patients Treated with Microsurgical Clipping.

Poor-grade aneurysmal subarachnoid hemorrhage (aSAH) has been associated with severe morbidity and high mortality. It has been demonstrated that early intervention is of paramount importance. The aim of our study is to evaluate the functional outcome and the overall survival of early microsurgically treated patients. Poor-grade aSAH patients admitted at our institution over fifteen years (January 2008 - December 2022) were included in our retrospective study. All participants underwent brain Computed Tomography Angiography (CTA). Fisher scale was used to assess the severity of hemorrhage. All our study participants underwent microsurgical clipping, and their functional outcome was assessed with the Glasgow Outcome Scale (GOS). We used logistic regression analysis to identify any parameters associated with a favorable outcome at 12 months. Cox proportional hazard analysis was also performed, identifying factors affecting the length of survival. Our study included 39 patients with a mean age of 54 years. Thirty of our participants (76.9%) were Hunt and Hess grade V, while the vast majority (94.9%) were Fisher grade 4. The observed six-month mortality rate was 48.6%. The mean follow-up time was 18.6 months. The functional outcome at six months was favorable in 6 patients (16.2%), increased to 23.5% at 12 months. Our data analysis showed that the age, as well as the employment of temporary clipping during surgery, affected the overall outcome. Management of poor-grade aSAH patients has been dramatically changed. Microsurgical clipping provides promising results in carefully selected younger patients.

Incidence and risk factors of contrast-induced nephropathy in acute stroke patients undergoing computed tomography angiography: A single-center study.

To investigate the prevalence and risk factors linked to contrast-induced nephropathy in this specific patient population, aiming to ensure the highest quality of clinical care. In a retrospective analysis, all patients who presented with an acute stroke to King Fahad Hospital, Jeddah, Emergency Department from March until November 2022 and underwent Computed Tomography Angiography (CTA) brain, Inclusion criteria were as follows: a baseline creatinine results and CTA examination performed within 24 hours of symptom onset and an available early (<5 days after CTA) follow-up creatinine result. Among 246 stroke patients in the emergency, 182 underwent brain CTA and 8.24% had Contrast-Induced Nephropathy (CIN). intracerebral hemorrhage (ICH) increased CIN risk 7-fold (OR=6.7; 95% CI: 1.23-33.3). Abnormal baseline raised CIN risk 8-fold (OR=7.8; 95% CI: 1.74-35.1). hypertension doubled the risk for CIN (OR=2.1; 95% CI: 1.26-6.98) CONCLUSION: The incidence of CIN was 8.2%, particularly elevated in patients with ICH, hypertension, tissue plasminogen administration, and abnormal baseline, necessitating vigilance in managing acute stroke cases.

A Study on the Optimization of Contrast Enhancement in Cerebrovascular CT in Hemorrhagic Stroke Patients

During the brain computed tomography angiography (Brain CTA) test of hemorrhagic stroke patients, we tried to find out the test method for optimizing contrast enhancement of cerebrovascular vessels by changing the location of the region of interest (ROI) and scan delay time. From September 2022 to February 2023, 80 patients who visited the emergency room and performed a Brain CTA test were tested, and 10 people in control group without disease were ROI set at C3 to C4 level and performed a test by 6-second delay scan as soon as contrast enhancement was performed on common carotid artery (CCA) with the naked eye. 40 people in the hemorrhagic stroke experiment group A setting the same test method as the control group were tested after A-0; 6 second, A-1; 8 second, A-2; 10 second, A-3; 12-second delay for 10 people each, and 30 people in experiment group B setting ROI at circle of willis level and as soon as contrast enhancement was performed in the middle cerebral artery (MCA) were tested after B-1; 2 second, B-2; 4 second, B-3; 6-second delay for 10 people each. The evaluation methods include quantitative evaluation that compares and analyzes the mean HU values and percentage values of internal carotid artery (ICA), MCA, superior sagittal sinus (SSS), and internal jugular vein (IJV) of the control group and experimental groups A and B, qualitative evaluation through reconstructed images, and significance evaluation was conducted using an independent sample t-test. As a result of the quantitative evaluation, the mean HU value of MCA in the experimental group was measured lower than that of the control group, 369 HU, but was generally close to 300 HU. In the MCA vs SSS percentage value, the experimental group B-2 was 0.7%, the closest value to the control group. As a result of the blind test through reconstructed images as a qualitative evaluation, the control group scored the highest with 16 points, and in the experimental group B-2 scored the highest with 15 points. As a result of significance evaluation through an independent sample t-test, the p-value of the control group and the experimental group B-2 was 0.408, which was evaluated as having no significant difference, and other experimental groups were evaluated that there was a significant difference. As a result of analyzing the test performed by changing the ROI position and scan delay time of control and experimental groups A and B, setting the ROI at the circle of willis level and testing after 4-second delay as soon as contrast enhancement is made in MCA will be useful for Brain CTA test in hemorrhagic stroke patients.

Optimizing contrast protocol for bone-subtraction CT angiography of intracranial arteries in normal dogs using 160-slice CT.

Bone-subtraction computed tomography angiography (CTA) (BSCTA) is a new technique designed to overcome the limitation of three-dimensional CTA, where the vessels surrounded by bone and calcification can be obscured. An optimal contrast CT protocol for intracranial artery visualization with BSCTA has yet to be established in dogs. The purpose of this study was to determine the optimal contrast protocol of CTA for visualizing intracranial artery using an automatic bone-subtraction technique in dogs. Brain CTA was performed four times for each of nine healthy beagle dogs to cover all the contrast protocols: two different contrast iodine concentrations (300 and 370mgI/mL) and two different contrast media injection rates (2 and 4mL/s). Bone removal post-processing was performed automatically by subtracting the non-enhanced CT data from the contrast CT data using a dedicated workstation. The bone-subtracted intracranial vessels were analysed for quantitative and qualitative evaluation. Quantitative evaluation showed significantly higher CT attenuation values for the group with a 370mgI/mL iodine content at a rate of 4mL/s than the two groups with a 300mgI/mL iodine content at the rates of 2 and 4mL/s (p<0.001). Qualitative assessment revealed significantly higher mean scores for the 370mgI/mL groups than the 300mgI/mL groups and significantly higher mean scores for the 4mL/s groups than the 2mL/s groups (p<0.05). The optimal contrast protocol for BSCTA suggests that high iodine material concentration and high injection rate should be used for strong arterial attenuation and great visualization of the intracranial arterial structure in dogs.

Morphological patterns of the cerebral arterial circle of Willis: Implication in subjects with ischemic stroke

Background: A stroke or cerebrovascular accident is associated with defects in the circle of Willis. The present research assessed whether differences in the anatomy of the circle of Willis were implicated in subjects affected by stroke. Materials and methods: A retrospective descriptive (cohort) study of images of 340 male and female subjects aged 15 to 75 years, referred for either brain Computed Tomography Angiography (CTA) or Magnetic Resonance Imaging (MRI) scan indicative of suspected stroke, was employed. A convenient sampling technique was used to obtain images from selected hospitals and radio-diagnostic centers with Computed Tomography (CT) and MRI scanners. Approval was obtained from the Federal Health Research Ethics Committee in accordance with institutional guidelines and principles, following permission and clearance (Approval Number: FHREC/2019/01/51/13-05-19). Patterns of morphology observed in the circle of Willis were data collected and stored in a non-identifiable format. Data obtained were analyzed with the Statistical Package for Social Science (SPSS) Inc, Chicago, IL, USA version 25.0. Results: Of the total 340 images evaluated, 256 (75.29%) subjects had ischemic stroke while 84 (24.71%) subjects had no stroke and were thus, considered to be apparently normal. Structural patterns in the circle of Willis mostly observed were the absence of the anterior communicating artery (10.94%) and the bilateral absence of the posterior communicating artery (10.16%). Conclusion: Morphological patterns of the cerebral arterial circle of Willis observed, were implicated in subjects affected with stroke in the present study population.

Image quality of spectral brain computed tomography angiography using halved dose of iodine contrast medium.

Reduction in iodinated contrast medium (CM) dose is highly motivated. Our aim was to evaluate if a 50% reduction of CM, while preserving image quality, is possible in brain CT angiography (CTA) using virtual monoenergetic images (VMI) on spectral CT. As a secondary aim, we evaluated if VMI can salvage examinations with suboptimal CM timing. Consecutive patients older than 18 years without intracranial stenosis/occlusion were included. Three imaging protocols were used: group 1, full CM dose; group 2, 50% CM dose suboptimal timing; and group 3, 50% CM dose optimized timing. Attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured in the internal carotid artery, M2 segment of the middle cerebral artery, and white matter for conventional images (CI) and VMI (40-200 keV). Qualitative image quality for CI and VMI (50 and 60 keV) was rated by 4 experienced reviewers. Qualitatively and quantitatively, VMI (40-60 keV) improved image quality within each group. Significantly higher attenuation and CNR was found for group 3 VMI 40-50 keV, with unchanged SNR, compared to group 1 CI. Group 3 VMI 50 keV also received significantly higher rating scores than group 1 CI. Group 2 VMI (40-50 keV) had significantly higher CNR compared to group 3 CI, but the subjective image quality was similar. VMI of 50 keV with 50% CM dose increases qualitative and quantitative image quality over CI with full CM dose. Using VMI reduces non-diagnostic examinations and may salvage CTA examinations deemed non-diagnostic due to suboptimal timing.

EVALUATION OF RADIATION DOSE IN MULTI-SLICE COMPUTED TOMOGRAPHY PROTOCOLS OF HEAD AND NECK REGIONS.

In head and neck computed tomography (CT) imaging, the optimisation of radiation dose is crucial due to the presence of radio-sensitive organs. This study aimed to evaluate the radiation dose in multi-slice CT for head and neck examinations. Volume CT dose index, dose length product and effective dose (E) were assessed for 10 head and neck CT scans performed on 292 adult patients (mean age 49.2±15.9y). The study resulted in median E values of 0.82, 1.62, 2.43, 0.93, 1.70, 0.83, 3.55, 6.25, 2.19 and 5.26mSv, respectively, for sinuses (non-contrast (NC)), sinuses (NC) and contrast-enhanced (CE), petrous bone (PTB)/internal auditory meatus (IAM) (NC+CE), PTB/IAM (NC), orbit (NC+CE), orbit (NC), brain with the orbit (NC), brain CT angiography (CTA) subtraction, neck (NC) and brain/neck (NC). Furthermore, the overall radiation doses of this institution were found to be below the values suggested by similar studies. However, optimisation of the dose is required for brain CTA.

Real World Experience with Viz.ai Automated Large Vessel Occlusion in CT Angiogram (P8-5.010)

<h3>Objective:</h3> To determine the accuracy of Viz.AI LVO at our large academic comprehensive stroke center. <h3>Background:</h3> Viz.AI LVO is an artificial-intelligence platform which analyzes brain computed tomography angiography (CTA) images in patients with suspected acute ischemic stroke (AIS) and sends an automated alert for suspected large vessel occlusions (LVO). Viz.AI reports high sensitivity and specificity (96.3% and 93.8%); we report our experience with Viz.AI LVO detection. <h3>Design/Methods:</h3> We performed a retrospective review of suspected stroke patients who had CTA ordered as a stroke code from September 2020–May 2021. Data was collected on sex, age, Viz.AI LVO alert, and CTA radiologist review (considered gold standard). True negative was defined as Viz negative, Radiology negative, False positive as Viz positive, Radiology negative, false negative as Viz negative, Radiology positive, and true positive as Viz positive, Radiology positive. LVO was defined as occlusion of the intracranial carotid (ICAT) or MCA (M1 or M2). Data collected included performance of Viz.AI LVO alert, sensitivity, specificity, positive predictive value, and negative predictive value. <h3>Results:</h3> Among 980 consecutive suspected AIS patients with CTA analyzed by Viz.AI, the mean age was 64.2 years (range 19–99) and 531 (54.3%) were female. Viz LVO autodetection alerted for 161 patients (16.4%). Radiologist review reported 85 patients (8.7%) with LVO as follows: 33 (38.8%) M2, 36 (42.4%) M1, and 16 (18.8%) ICAT. The following were adjudicated: 805 true negatives, 90 false positives, 14 false negatives, and 71 true positives. Sensitivity was 83.5%, specificity 89.9%, PPV 44.1%, and NPV 98.3%. All 14 false negatives were M2 occlusions. The median time to alert (TTA) was 11 min (range 6–656). <h3>Conclusions:</h3> In our series of AIS patients evaluated with CTA at an academic CSC, Viz.AI automated LVO detection performed well with a sensitivity of 83.5%, specificity of 89.9%, and a median TTA of 11 minutes. <b>Disclosure:</b> Dr. Mannix has nothing to disclose. Ms. Penhos has nothing to disclose. Shahid Nimjee has nothing to disclose. Mohammad Taimur Shujaat has nothing to disclose. Ms. Hammond-Heaton has nothing to disclose. Dr. Vitellas has nothing to disclose. Dr. Lee has nothing to disclose.

Proposal of multimodal computed tomography-based scoring system in prediction of hemorrhagic transformation in acute ischemic stroke.

The routinely used computed tomography (CT)-based workup in the setting of acute ischemic stroke (AIS) includes non-contrast brain CT, CT angiography (CTA), and CT perfusion. Several CT, CTA, CTP-based radiological biomarkers of hemorrhagic transformation (HT) were reported. To assess the predictive value of the combined multimodal CT parameters for HT after AIS and proposal of predictive scoring scale. The source images of the NCCT, CTA and CTP of 282 AIS patients involving the anterior circulation (HT = 91, non-HT = 191) were retrospectively reviewed and the following biomarkers were recorded and analyzed: Early subtle ischemic signs, hyperdense middle cerebral artery sign (HMCAS) and Alberta Stroke Program Early CT Score (ASPECTS) < 7 in NCCT, large-vessel occlusion (LVO), clot burden score (CBS) < 6, large-vessel occlusion, poor collateral score (CS) and Tmax > 6s ≥ 56.5ml. A scoring system to predict HT based on these biomarkers was developed. Each biomarker counts for a single point with the total score ranging from 0 to 7. All the aforementioned multimodal CT biomarkers and the selected cut offs were significantly associated with higher HT risk. The calculated scores were statistically significant different between the HT and the non-HT groups with AUC 0.761 (95% CI 0.703-0.819, P < 0.0000001). Rates of HT were approximately five times higher in patients with score ≥ 3. Multimodal CT-based scoring system may provide highly reliable predictive model of hemorrhagic transformation in acute ischemic stroke.

Recanalization Rate and Clinical Outcomes of Intravenous Tissue Plasminogen Activator Administration for Large Vessel Occlusion Stroke Patients.

Stroke caused from large vessel occlusion (LVO) has emerged as the most common stroke subtype worldwide. Intravenous tissue plasminogen activator administration (IV-tPA) and additional intraarterial thrombectomy (IA-Tx) is regarded as standard treatment. In this study, the authors try to find the early recanalization rate of IV-tPA in LVO stroke patients. Total 300 patients undertook IA-Tx with confirmed anterior circulation LVO, were analyzed retrospectively. Brain computed tomography angiography (CTA) was the initial imaging study and acute stroke magnetic resonance angiography (MRA) followed after finished IV-tPA. Early recanalization rate was evaluated by acute stroke MRA within 2 hours after the IV-tPA. In 167 patients undertook IV-tPA only and 133 non-recanalized patients by IV-tPA, additional IA-Tx tried (IV-tPA + IA-Tx group). And 131 patients, non-recanalized by IV-tPA (IV-tPA group) additional IA-Tx recommend and tried according to the patient condition and compliance. Early recanalization rate of LVO after IV-tPA was 12.0% (36/300). In recanalized patients, favorable outcome (modified Rankin Scale, 0-2) was 69.4% (25/36) while it was 32.1% (42/131, p<0.001) in non-recanalized patients. Among 133 patients, nonrecanalized after intravenous recombinant tissue plasminogen activator and undertook additional IA-Tx, the clinical outcome was better than not undertaken additional IA-Tx (favorable outcome was 42.9% vs. 32.1%, p=0.046). Analysis according to the perfusion/diffusion (P/D)-mismatching or not, in patient with IV-tPA with IA-Tx (133 patients), favorable outcome was higher in P/ D-mismatching patient (52/104; 50.0%) than P/D-matching patients (5/29; 17.2%; p=0.001). Which treatment tired, P/D-mismatching was favored in clinical outcome (iv-tPA only, p=0.008 and IV-tPA with IA-Tx, p=0.001). The P/D-mismatching influences on the recanalization and clinical outcomes of IV-tPA and IA-Tx. The authors would like to propose that we had better prepare IA-Tx when LVO is diagnosed on initial diagnostic imaging. Furthermore, if the patient shows P/D-mismatching on MRA after IV-tPA, additional IA-Tx improves treatment results and lessen the futile recanalization.

Cortical Superficial Siderosis and Transient Focal Neurological Episode Preceding Lobar Hemorrhage in Cerebral Amyloid Angiopathy.

Cortical Superficial Siderosis and Transient Focal Neurological Episode Preceding Lobar Hemorrhage in Cerebral Amyloid Angiopathy.

Paediatric effective radiation doses during brain computed tomography angiography procedure

In comparison to adults and paediatric are more sensitive to ionizing radiation exposure. Computed tomography (CT) is now the dominant source of medical radiologic tests for patients, accounting for more than 70% of total doses to the general public. Paediatric CT brain scans (with and without contrast) are routinely performed for a variety of clinical reasons. As a result, this parameter must be calculated in order to determine relative radiation risk. The goal of this study is to assess the radiation risk to children during CT brain diagnostic procedures. Three hundred fifty three child patients' radiation risk doses were assessed over the course of a year. The mean and ranged of the children's radiation doses were 40.6 ± 8.8 (27.8–45.8) CTDIvol (mGy) and 850 ± 230 (568.1–1126.4) DLP (mGy.cm) for the brain with contrast medium. For CT brain without contrast, the patients' doses were 40.9 ± 9.4 (14.27–64.07) CTDIvol (mGy), and 866.1 ± 289.3 (203.6–2484.9) DLP (mGy.cm). The characteristics related to the radiation dose were retrieved from the scan protocol generated by the CT system by the participating physicians after each procedure. Furthermore, optimizing the CT acquisition parameter is critical for increasing the benefit while lowering the procedure's radiogenic risk. The patients' radiation dose is comparable with the most previously published studies and international diagnostic reference levels (DRLs). Radiation dose optimization is recommended due to high sensitivity of the paediatric patients to ionizing radiation.

Chronic Headache Attributed to Vertebrobasilar Insufficiency.

Vertebrobasilar insufficiency, a condition characterized by poor blood flow to the posterior portion of the brain, can cause headaches. However, the exact underlying mechanism is not yet fully understood. The patient enrolled in our study reported experiencing intermittent headaches radiating from the left shoulder, similar to chronic tension-type headaches. His aggravated headache and severe left vertebral artery stenosis were detected by brain computed tomography angiography. Stent insertion successfully expanded the patient’s narrowed left vertebral artery orifice. Subsequently, the patient’s headaches improved without recurrence during the one-year follow-up period. In summary, chronic headaches attributed to vertebrobasilar insufficiency in this study, improved after stent insertion to reverse severe left vertebral artery stenosis.

Thromboembolic hazard in hereditary hemorrhagic telangiectasia.

A 23-year-old woman with hereditary hemorrhagic telangiectasia was found in her bedroom presenting right-side hemiparesis and aphasia. Brain computed tomography angiography (CTA) showed a complete occlusion of left-medium cerebral artery (Panel A) that required mechanical thrombectomy. CTA revealed the typical arteriovenous malformations in the lungs (Panel B) but not in the brain or liver. A bubble contrasted echocardiography ruled out intracardiacal shunts. Furthermore, repletion defects were found in subsegmentarial pulmonary arteries (Panel C, amplified in the inset). No thrombus was detected in lower extremity veins with Doppler-ecography, and thrombophilia screening was negative. Urgent thrombectomy, rehabilitation, and anticoagulation reduced neurological sequels to hand dizziness and mild concentration complaints. Arteriovenous malformations were embolized. Hereditary hemorrhagic telangiectasia, also known as Rendu–Osler–Weber disease, is an autosomical-dominant condition characterized by angiodysplastic lesions and arteriovenous malformations. Traditionally, the hemorrhagic manifestations have received all the attention. Nonetheless, arteriovenous malformations can bypass pulmonary circulation and permit paradoxical embolisms (see Figure 1). The authors declares they have no conflicts of interest. Patient gave informed consent for the publication of this case report.

Predictors and Outcomes of Salvaging the Corticospinal Tract After Thrombectomy in Basilar Artery Occlusion Stroke.

BackgroundRegional eloquence of brainstem structures may contribute to neurological status in basilar artery occlusion (BAO) stroke. The corticospinal tract (CST) which is vulnerable to BAO is important for motor activity. This study investigated the impact of CST salvage on outcomes and its associated factors in patients with BAO treated with thrombectomy.MethodsWe retrospectively investigated 88 patients with BAO admitted ≤24 h after onset and presented with motor deficits and who underwent thrombectomy. Patients with a pre-stroke modified Rankin Scale (mRS) score of 4–5 who did not undergo baseline brain computed tomography angiography were excluded. CST salvage was evaluated using follow-up imaging (magnetic resonance imaging [MRI] or computed tomography when MRI was not available) after thrombectomy. A good outcome was defined as a 3-month mRS score of ≤2 or 3 if a patient's pre-stroke mRS score was 3. The associations between CST salvage and outcomes and clinical parameters were analyzed using logistic regression analyses.ResultsThirty-nine (44.3%) patients had CST salvage and the same number of patients had good outcomes. CST salvage was independently associated with a good outcome [adjusted odds ratio (aOR): 18.52, 95% confidence interval (CI): 4.31–79.67, p < 0.001]. After adjusting for confounders, atrial fibrillation (aOR: 3.92, 95% CI: 1.18–13.00, p = 0.026), location of occlusion (mid-BAO; aOR: 0.21, 95% CI: 0.06–0.72, p = 0.013), length of occlusion (involved segment of BAO <2; aOR: 4.77, 95% CI: 1.30–17.59, p = 0.019), and onset-to-puncture-time ≤180 min (aOR: 4.84, 95% CI: 1.13–20.75, p = 0.034) were significantly associated with CST salvage.ConclusionCST salvage was associated with good functional outcomes in patients with BAO treated with thrombectomy. The presence of atrial fibrillation, location and length of BAO may predict CST salvage after thrombectomy, and rapid treatment with thrombectomy may protect this eloquent tract in these patients.

Trochlear Nerve Palsy Caused by a Superior Cerebellar Artery Aneurysm

Purpose: We report a case of trochlear nerve palsy caused by a superior cerebellar artery (SCA) aneurysm.Case summary: A 34-year-old woman visited our clinic complaining of distance diplopia and a temporal headache 7 days in duration. She had no previous relevant medical or trauma history. Her visual acuity; intraocular pressure; and pupil, anterior segment, and fundus evaluations were unremarkable. Extraocular muscle examination (EOM) revealed six prism diopters (PD) of right hypertropia in the primary gaze; this worsened when the head was tilted to the right. Brain magnetic resonance imaging revealed a round solid nodule between the temporal lobe and pons; we thus suspected a petrous ridge meningioma. She was referred to our neurosurgery department for meningioma treatment. However, 1 hour later, she visited our emergency room with severe headache and nausea. Brain computed tomography angiography revealed a subarachnoid hemorrhage and a ruptured SCA aneurysm. Emergency coil embolization was successfully performed. Four weeks after surgery, the right hypertropia was slightly decreased. Four months later, the diplopia had disappeared and EOM revealed orthotropia.Conclusions: SCA aneurysms are rare and can be misdiagnosed even after radiological examination. Our case emphasizes that an SCA aneurysm should be considered during the differential diagnosis of patients with diplopia and headache.