Diagnostic performance of computed tomography-digital subtraction angiography and conventional magnetic resonance imaging for evaluating the vascularity of osseous spinal tumors.

BACKGROUND AND PURPOSE: Patients with hypervascular spinal tumors may have severe blood loss during tumor resection, which increases the risks of perioperative morbidity and mortality. However, the preoperative evaluation of tumor vascularity may be challenging; moreover, the reliability of the data obtained in conventional preoperative noninvasive imaging is debatable. In this study, we compared conventional magnetic resonance imaging (MRI) and subtraction computed tomography angiography (CTA) in terms of their performance in vascularity evaluation. The catheter digital subtraction angiography (DSA) technique was used as a reference standard. METHODS: This study included 123 consecutive patients with spinal tumor who underwent subtraction CTA, catheter DSA, and subsequent surgery between October 2015 and October 2021. Data regarding qualitative and semiquantitative subtraction CTA parameters and conventional MRI signs were collected for comparison with tumor vascularity graded through catheter DSA. The diagnostic performance of qualitative CTA, quantitative CTA, and conventional MRI in assessing spinal tumor vascularity was analyzed. RESULTS: Qualitative subtraction CTA was the best noninvasive imaging modality in terms of diagnostic performance (area under the receiver operating characteristic curve [AUROC], 0.95). Quantitative CTA was relatively inferior (AUROC, 0.87). MRI results had low reliability (AUROC, 0.51 to 0.59). Intratumoral hemorrhage and prominent foraminal venous plexus were found to be the specific signs for hypervascularity (specificity 93.2%). CONCLUSIONS: Qualitative subtraction CTA offers the highest diagnostic value in evaluating spinal tumor vascularity, compared to quantitative CTA and MRI. Although conventional MRI may not be a reliable approach, certain MRI signs may have high specificity, which may be crucial for assessing spinal tumor vascularity.

Dynamic evaluation of unruptured intracranial aneurysms by 4D-CT angiography: comparison with digital subtraction angiography (DSA) and surgical findings.

BACKGROUND: This study was to prospectively investigate the feasibility of four-dimensional computed tomography angiography (4D-CTA) with electrocardiogram-gated (ECG) reconstruction for preoperative evaluation of morphological parameters, and compared with digital subtraction angiography (DSA). We also aimed to detect pulsation in unruptured intracranial aneurysms (UIAs) by using 4D-CTA, as a potential predicting factor of growth or rupture. MATERIALS: 64 patients with 64 UIAs underwent ECG-gated dynamic 4D-CTA imaging before treatment, of which 46 patients additionally underwent DSA. Original scanning data were reconstructed to produce 20 data sets of cardiac cycles with 5%-time intervals. The extent of agreement on UIAs morphological features assessed with 4D-CTA and DSA was estimated using the k coefficient of the Kappa test. The radiation doses were also calculated and compared between 4D-CTA and DSA. In the aneurysmal surgically treated in our institution, we were able to compare the surgical findings of the aneurysm wall with 4D-CTA images. We performed long-term follow-up on untreated patients. RESULTS: The morphological characteristics detected by 4D-CTA and DSA were consistent in aneurysm location (k = 1.0), shape (k = 0.76), maximum diameter (k = 0.94), aneurysm neck (k = 0.79) and proximity to parent and branch vessels (k = 0.85). 4D-CTA required lower radiation doses (0.32 ± 0.11 mSv) than DSA (0.84 ± 0.37 mSv, P < 0.001). Pulsation was detected in 26 of the 64 unruptured aneurysms, and all underwent neurosurgical clipping or interventional embolization. In aneurysms surgically treated in our hospital, we observed a significant correlation between 4D-CTA findings and surgical evaluation of the aneurysmal wall, in particular the irregular pulsations detected on 4D-CTA have demonstrated to correspond to dark-reddish thinner wall at surgery. CONCLUSIONS: In this proof-of-concept study, 4D-CTA provided real-time, non-invasive preoperative assessments of UIAs comparable to DSA. Moreover, optimal correlation between the irregular pulsation detected by 4D-CTA and the surgical findings support a possible role of this technique to identify aneurysms with a higher risk of rupture.

Intraoperative DSA-guided minimal approach for craniocervical junction DAVFs obliteration.

BACKGROUND: Dural arteriovenous fistulas (DAVFs) are a group of diseases involving problematic shunts between dural arteries and venous structures such as sinuses, meningeal veins, or even cortical veins. To focus on craniocervical junction dural arteriovenous fistulas (DAVFs), we introduce a minimally invasive technique with midline incision combined with intraoperative digital subtraction angiography (DSA). This hybrid technique can minimize the incision wound to an average of 6 cm which leads to less destruction and lower risk of adverse events. METHOD: Using this minimally invasive approach, surgical obliteration was achieved in 6 patients with craniocervical junction DAVFs. A minimal midline incision was made over the C1-2 level, measuring approximately 5 to 7 cm in length. C1 hemilaminectomy was performed for DAVF obliteration followed by intraoperative DSA for confirmation of complete obliteration. RESULTS: Among these 6 patients, the radiculomedullary artery was the most common feeding artery. The mean length of the operation (including DSA performance) was 6.5 ± 1.4 h. None of these cases showed cerebrospinal fluid leakage or exacerbation of neurological symptoms after the operation. CONCLUSION: Using intraoperative DSA, the minimally invasive technique offers more precise but less destructive access than conventional far lateral suboccipital craniotomy. Most importantly, intraoperative DSA provided verification of complete closure for shunts that could not be examined for indocyanine green (ICG) dye because the microscope did not have a clear line of sight. In our experience, this technique shows encouraging results of fistula obliteration.

Anatomical information of the lenticulostriate arteries on high-resolution 3D-TOF MRA at 3 T: comparison with 3D-DSA.

PURPOSE: As the lenticulostriate arteries (LSAs) perfuse neurologically important areas, it is necessary to accurately assess the origin and number of the LSAs before surgery. Although three-dimensional time-of-flight MR angiography (3D-TOF MRA) is a non-invasive procedure, it requires high-resolution (HR) images to depict the LSAs with a small diameter. Therefore, we performed 3D-TOF MRA with the maximum HR (HR-MRA) using a 3 T scanner to examine whether a good depiction of the LSAs, equivalent to that of digital subtraction angiography (DSA), could be obtained. METHODS: Our study group comprised 16 consecutive patients who underwent HR-MRA and 3D-DSA. In both studies, we evaluated the localization of the origin from M1, M2, or A1 segments, their number of stems, and depiction. RESULTS: There was no significant difference in the visualization of the LSAs between HR-MRA and 3D-DSA (P values; M1, M2, and A1 = 0.39, 0.69, and 0.69, respectively), and both the number of stems and the localization of the origin of the LSAs corresponded between the two examinations. CONCLUSION: HR-MRA at 3 T can depict the LSA well. It reveals the number of the LSA stems and the LSA origin comparatively with DSA.

A Rare Triploid Involving the Coexistence of Glioblastoma Multiforme, Arteriovenous Malformation and Intracranial Aneurysm: Illustrative Case and Literature Review.

The coexistence of glioblastoma multiforme (GBM) and arteriovenous malformation (AVM) is rarely reported in the literature. According to the present literature, these GBM or glioma-related vascular malformations may present simultaneously in distinct regions of the brain or occur in the same area but at different times. So far, these distinct hypervascular glioblastomas have been described but are not classified as a separate pathological entities. Considering their heterogeneity and complexity, all the above mentioned cases remain challenging in diagnosis and therapeutic modality. Likewise, there is a paucity of data surrounding the simultaneous presentation of GBM with intracranial aneurysms. In the literature, the independent concurrence of these three intracranial lesions has never been reported. In this article, we present a case who suffered from intermittent headaches and dizziness initially and further radiographic examination revealed an internal carotid artery (ICA) aneurysm that occurred in the patient with coexisting GBM and AVM. Surgical intervention for tumor and AVM removal was performed smoothly. This patient underwent endovascular coiling for the ICA aneurysm 4 months postoperatively. In addition, we also review the current literature relating to this rare combination of medical conditions.

Characteristics of headache during and/or after coronary intervention: A prospective observational study.

INTRODUCTION: Headache during and/or after coronary intervention is common but has received little attention from cardiologists and neurologists. The purpose of this study was to investigate the incidence, risk factors, and possible mechanism of coronary intervention-related headache. METHODS: Using a prospective observational design, we identified consecutive patients with coronary intervention from May 2020 to August 2020. Patients were followed up with questionnaires immediately after coronary intervention and 24 h, 72 h, 1 week and 2 weeks after the intervention. RESULTS: In total, 94 patients were enrolled, and 71 patients ultimately completed the 2-week follow-up. Among 71 patients, headache developed during and/or after coronary intervention in 18 (25.4%) patients. Two different types of headache related to coronary intervention were observed: One during and another after coronary intervention. Headache characteristics are described in detail. A history of previous headache was an independent risk factor for coronary intervention-related headache (p < 0.01). CONCLUSIONS: Coronary intervention-related headache has an incidence of 25.4%, and previous headache history was an independent risk factor. Moreover, considering that there are no relevant diagnostic criteria, it is suggested that the definition of coronary intervention-related headache should be established in the International Classification of Headache Disorders.

Predictors of preoperative cognitive dysfunction in adults with Moyamoya disease: a preliminary research.

OBJECTIVE: To explore potential risk factors of preoperative cognitive dysfunction in adult patients with moyamoya disease (MMD) and discuss significance of moyamoya vessels. METHODS: The author reviewed adult MMD patients harboring no parenchymal infarction or hemorrhage underwent a standardized neuropsychological assessment test battery from December 2018 to May 2019. The authors defined patients with cognitive dysfunction as cognitive impairment shown on 3 or more neuropsychological tests. According to the presence of cerebral angiography, arterial stenosis, moyamoya vessels, and compensatory arteries were conducted. Univariate and multivariate analyses were performed to identify predictors for cognitive dysfunction before surgery. Subgroup analyses by onset type and Suzuki stage were carried out to identify specific predictors for preoperative cognitive dysfunction. RESULTS: In total, 29 of 92 (31.52%) patients had cognitive dysfunction. Multivariate analysis showed that moyamoya vessels generating from left hemisphere was recognized as independent predictor for cognitive dysfunction (P = 0.025, OR [95%CI], 0.085 [0.012-0.874]). For patients in left ICA-moyamoya subgroup, 19 of 45 (42.22%) cases with sparse moyamoya vessels had cognitive dysfunction (P = 0.031), while 22 (91.67%) of patients with dense moyamoya vessels had normal cognition (P = 0.004). Moyamoya vessels arising from ophthalmic artery had no significant association with cognitive dysfunction (P = 0.111). Multivariate analysis found that moyamoya vessels originating from left ICA was recognized as independent predictors for preoperative cognitive dysfunction (P = 0.048, OR [95%CI], 0.394 [0.132-0.926]). CONCLUSIONS: Moyamoya vessels arising from left hemisphere was a risk factor for the preoperative cognitive dysfunction in adult patients with MMD, with the denser moyamoya vessels, the less cognitive dysfunction. The current study offers a new perspective of moyamoya vessels and supporting data for choosing MMD candidates on cerebral revascularization.

Isolated ruptured dissecting aneurysm of PICA with extremely narrow neck managed by a novel endovascular technique-a case report and review of literature.

Dissecting aneurysms of posterior inferior cerebellar artery (PICA) are usually extensions of vertebral artery dissection. Isolated dissecting aneurysms of PICA are extremely rare. A 5-month-old female child presented with history of fall from a height of around 2 ft., followed by incessant crying and multiple episodes of vomiting. The anterior fontanelle was lax. Plain CT scan brain showed IVH in the fourth ventricle with no hydrocephalus. Twenty-four hours after admission, the child had one episode of vomiting and became unresponsive. The child was intubated, and a repeat CT scan brain showed thick acute SDH in the posterior fossa with hydrocephalus. Emergency suboccipital craniectomy and evacuation of thick acute subdural hematoma were done. Organized clot noted in the midline between the tonsils was not removed. Digital subtraction angiography (DSA) done 48 h after surgery showed ruptured dissecting aneurysm of left PICA. Endovascular temporary parent artery occlusion by coil deployment was performed, after which a check angiogram revealed complete exclusion of aneurysm from circulation. Endovascular proximal parent artery occlusion is the preferred treatment modality for dissecting aneurysms of PICA. Selective coil or Onyx embolization of the aneurysm with parent vessel preservation technique is a valid and increasingly used alternative. In this case, a novel technique of endovascular temporary parent artery occlusion by coil deployment was performed successfully. This technique may be recommended in select cases.

The applicability research of the diagnostic criteria for 6.7.2 angiography headache in the international classification of headache disorders-3rd edition.

BACKGROUND: Angiography headache (AH) is common but not negligible, and the criteria for AH have been based on only a few studies. The purpose of this study was to investigate the incidence, risk factors and possible mechanism of AH and reappraise the diagnostic criteria for AH in the International Classification of Headache Disorders 3 (ICHD-3). METHODS: Two hundred and seventy-nine patients completed this prospective, non-randomized study, including 107 patients who underwent cerebral angiography, 101 patients who underwent coronary intervention and 71 patients who underwent extremities arterial intervention. Patients were followed up with questionnaires immediately after the procedure and 24 h, 72 h, 1 week and 2 weeks after the procedure. RESULTS: The incidence of headache was 22.4% (24/107) in cerebral angiography group, 23.8% (24/101) in coronary intervention group, and 16.9% (12/71) in extremities arterial intervention group. Headache still occurred in 12.1% (13/107), 14.9% (15/101) and 11.3% (8/71) of patients 24 h after the procedure in the three groups, respectively. Two types of headache were observed in cerebral angiography group and coronary intervention group, one during and one after the procedure, while only postoperative headache was observed in extremities arterial intervention group. Previous headache history was a risk factor for headache in the three groups (p = 0.003 in cerebral angiography group, p = 0.006 in coronary intervention group, and p = 0.016 in extremities arterial intervention group). In addition, female (p = 0.008) was a risk factor for cerebral angiography group. Headache characteristics were described in detail. CONCLUSIONS: The diagnostic criteria for 6.7.2 angiography headache in ICHD-3 may miss a number of cerebral AH with onset later than 24 h after the procedure. Therefore, it is recommended to revise it according to the literature and further studies. The incidence of headache was high during and after angiography and interventional procedure. It was suggested that the definition of headache due to coronary intervention and headache due to extremities arterial intervention should be added in ICHD.

Giant "heart appearance-like sign" on MRI in bilateral ponto-medullary junction infraction: case report.

BACKGROUND: Bilateral medial medullary infarction (MMI) is uncommon and bilateral medial pons infarction (MPI) is even rarer. "Heart appearance" on magnetic resonance imaging (MRI) is a characteristic presentation of bilateral medial medullary infarction (MMI). CASE PRESENTATION: We present 67-year-old Chinese diabetic and hypertensive female patient affected with "heart appearance-like" infarction in bilateral ponto-medullary junction on MRI. Abnormal signal was observed in the bilateral ponto-medullary junction on T1, T2, fluid-attenuated inversion recovery and apparent diffusion coefficient (ADC). The whole brain digital subtraction angiography (DSA) showed the basilar artery and vertebral artery remained intact. Therefore, we speculated that the bilateral ponto-medullary junction infarction might be caused by the deep perforating branch of the basilar artery. CONCLUSIONS: As far as we know, the "heart appearance-like" infraction in bilateral ponto-medullary junction was not reported. Our case also suggests that bilateral ischemic infraction involvement of the medulla and pon is possible even in the context of an intact basilar artery.

Is four-dimensional CT angiography as effective as digital subtraction angiography in the detection of the underlying causes of intracerebral haemorrhage: a systematic review.

PURPOSE: To determine whether the sensitivity and specificity of four-dimensional CTA (4D-CTA) are equivalent to digital subtraction angiography (DSA) in the detection of underlying vascular abnormalities in patients with intracerebral haemorrhage (ICH). METHODS: A systematic review of studies comparing 4D-CTA with DSA in the detection of the underlying structural causes of ICH was performed on the literature published between 1998 and 2019. RESULTS: We identified a total of 237 articles from PubMed, SCOPUS and Web of Science using the following Medical Subject Headings (MeSH) terms: primary intracerebral haemorrhage, 4D-CTA, DSA, cerebral haemorrhage, angiography, digital subtraction, arteriovenous malformations, 4D, CTA, dynamic-CTA and time-resolved CTA. Following the removal of duplicate publications and articles failing to meet our inclusion criteria, there were four articles potentially viable for analysis. Therefore, there were not sufficient studies to provide a statistically meaningful meta-analysis. CONCLUSION: The review of current literature has demonstrated that there are few published studies comparing 4D-CTA with DSA in spontaneous ICH, with only four suitable studies identified for potential analysis. However, due to the restricted number of patients and high sensitivity and specificity of 3 studies (100%), performing a meta-analysis was not meaningful. Qualitative analysis of the data concluded that 4D-CTA has the diagnostic potential to replace invasive DSA in certain cases with vascular abnormalities. However, further research studies directly comparing 4D-CTA with DSA using larger prospective patient cohorts are required to strengthen the evidence base.

Automatic Remasking of Digital Subtraction Angiography Images in Pulmonary Angiography.

In pulmonary angiography, the heartbeat creates artifacts that hinder extraction of blood vessel images in digital subtraction angiography. Remasking according to the cardiac phase of the angiogram may be effective but has yet to be automated. Here, automatic remasking was developed and assessed according to the cardiac phase from electrocardiographic information collected simultaneously with imaging. Manual remasking, fixed remasking, and our proposed automatic remasking were applied to 14 pulmonary angiography series from five participants with either chronic thromboembolic pulmonary hypertension or pulmonary arteriovenous malformation. The processing time and extent of artifacts from the heartbeat were compared. In addition, the peak signal-to-noise ratio (PSNR) was measured from differential images between mask image groups before the injection of the contrast medium to investigate optimal mask images. The mean time required for automatic remasking was 4.7 s/series, a significant reduction in processing time compared with the mean of 266 s/series for conventional manual processing. A visual comparison of the different approaches showed virtually no misregistration artifacts from the heartbeat in manual or automatic remasking according to cardiac phase. The results from measuring the PSNR for differential images between mask image groups also showed that smaller cardiac phase difference and time difference between two images ensure higher PSNR (p < 0.01). Automatic remasking according to the cardiac phase was fast and easy to implement and reduced misregistration artifacts from heartbeat.

Computed Tomography Angiogram Derived From Computed Tomography Perfusion Done with Low Iodine Volume Protocol Preserves Diagnostic Yield for Middle Cerebral Artery-M2 Occlusions.

BACKGROUND: Computed tomography angiogram (CTA) derived from computed tomography perfusion (CTP) has been proposed to avoid addition of separate CT perfusion protocol for selection of large vessel occlusion in acute stroke patients. Previous studies have validated this technique for proximal large vessel occlusions. In this study, we test reliability for identifying M2 occlusions on CTA derived from CTP. METHODS: Through a retrospective search of the institutional thrombectomy database, we identified 28 cases with M2-MCA occlusion, of which 24 met the inclusion criteria for analysis. An additional 20 cases without M2-MCA occlusion (either normal or M1-MCA occlusion) were randomly mixed in the database to reduce observer bias. The baseline images of the CTP study in these 48 cases were then independently analyzed by 3 readers with varying level of expertise. The digital subtraction angiography (DSA) images were also independently reviewed where available. The percentage of agreement among reviewers as well as the probability of agreement of the reviewers, when compared to the DSA findings was also calculated. RESULTS: The observed agreement for the image quality amongst the 3 readers (n = 48) varied between 0.78 and 0.95 and tended to be higher for the M1 segment MCA and lower for distal M2-MCA. The observed agreements comparing 3 image reviewers versus DSA in M2 patients (n = 24) was 98% for identifying occlusion (95% CI 95%-100%), 94% for identifying proximal M2 occlusion (95% CI 88%-98%), and 91% (95% CI 84%-97%) and 90% (95% CI 83%-95%), respectively for correctly identifying inferior and superior branch of M2 occlusion. CONCLUSION: CTA data derived from CT Perfusion study preserves diagnostic yield for correctly identifying M2 occlusion.

Spot fluoroscopy: a novel innovative approach to reduce radiation dose in neurointerventional procedures.

Background Increased interest in radiation dose reduction in neurointerventional procedures has led to the development of a method called "spot fluoroscopy" (SF), which enables the operator to collimate a rectangular or square region of interest anywhere within the general field of view. This has potential advantages over conventional collimation, which is limited to symmetric collimation centered over the field of view. Purpose To evaluate the effect of SF on the radiation dose. Material and Methods Thirty-five patients with intracranial aneurysms were treated with endovascular coiling. SF was used in 16 patients and conventional fluoroscopy in 19. The following parameters were analyzed: the total fluoroscopic time, the total air kerma, the total fluoroscopic dose-area product, and the fluoroscopic dose-area product rate. Statistical differences were determined using the Welch's t-test. Results The use of SF led to a reduction of 50% of the total fluoroscopic dose-area product (CF = 106.21 Gycm2, SD = 99.06 Gycm2 versus SF = 51.80 Gycm2, SD = 21.03 Gycm2, p = 0.003884) and significant reduction of the total fluoroscopic dose-area product rate (CF = 1.42 Gycm2/min, SD = 0.57 Gycm2/s versus SF = 0.83 Gycm2/min, SD = 0.37 Gycm2/min, p = 0.00106). The use of SF did not lead to an increase in fluoroscopy time or an increase in total fluoroscopic cumulative air kerma, regardless of collimation. Conclusion The SF function is a new and promising tool for reduction of the radiation dose during neurointerventional procedures.

Inter- and intra-rater agreement in the assessment of the vascularity of spinal metastases using digital subtraction angiography tumor blush.

Background Preoperative embolization is based on the preoperative digital subtraction angiography (DSA) tumor blush, and as such is considered the "gold standard" for determining tumor vascularity. However, to our knowledge reliability studies evaluating vascularity ratings of DSA tumor blush in spinal metastases have not been published previously. Purpose To evaluate inter- and intra-rater agreement in the assessment of the vascularity of spinal metastases using DSA tumor blush. Material and Methods This reliability study included 46 patients with symptomatic metastatic spinal cord compression requiring surgery. DSA data stored in the hospital picture archiving and communication system (PACS) from the participants of a randomized controlled trial were used. Inter- and intra-rater agreement on vascularity assessment using DSA tumor blush according to a three-step ordinal scale was evaluated: no hypervascularity; moderate hypervascularity; and pronounced hypervascularity. The statistical analysis was based on the linear weighted kappa's for multiple raters that extend Cohen's κ. Three raters and κ = 0.2 in the null hypothesis implied that the power of the study was 0.96. Results Inter- and intra-rater agreements were moderate in rating the vascularity of spinal metastases and the agreements were significantly higher than the κ = 0.20 in the null hypothesis ( P = 0.0002 and P = 0.0001). The κ value for inter-rater agreement was 0.57 (95% confidence interval [CI], 0.41-0.72) and for intra-rater agreement 0.55 (95% CI, 0.38-0.71). Conclusion There is moderate inter-rater and intra-rater agreement in classifying the vascularity of spinal metastases on a three-step ordinal scale for DSA tumor blush.

Significant dose reduction for pediatric digital subtraction angiography without impairing image quality: preclinical study in a piglet model.

OBJECTIVE: The purpose of this study was to validate the hypothesis that image quality of digital subtraction angiography (DSA) in pediatrics is not impaired when using a low-dose acquisition protocol. MATERIALS AND METHODS: Three piglets corresponding to common pediatric population sizes were used. DSA was performed in the aorta and renal, hepatic, and superior mesenteric arteries using both the commonly used reference standard and novel radiographic imaging noise reduction technologies to ensure pairwise radiation dose and image quality comparison. The air kerma per frame at the interventional reference point for each DSA acquisition was collected as a radiation dose measure, and image quality was evaluated by five interventional radiologists in a randomized blinded fashion using a 5-point scale. RESULTS: The mean air kerma (± SD) at the interventional reference point with the novel x-ray imaging noise reduction technology was significantly lower (1.1 ± 0.8 mGy/frame) than with the reference technology (4.2 ± 3.0 mGy/frame, p = 0.005). However, image quality was statistically similar, with average scores of 3.2 ± 0.4 and 3.1 ± 0.5 for the novel and reference technologies, respectively (p = 0.934); interrater absolute agreement was 0.77. CONCLUSION: The DSA radiation dose for pediatrics can be reduced by a factor of four with a novel x-ray imaging noise reduction technology without deterioration of image quality.

Cerebral Angiography and Neurobehavioral Patterns in a Non-human Primate Middle Cerebral Artery Occlusion Model.

BACKGROUND/AIM: Ischemic stroke is a major health concern globally and developing reliable animal models is crucial for understanding its pathophysiology. This study evaluated the relationship between cerebral angiographic findings and neurologic dysfunction in an acute non-human primate thromboembolic stroke model and determined the minimum clot length for suitable middle cerebral artery (MCA) occlusion. MATERIALS AND METHODS: A thromboembolic stroke model was developed by injecting autologous blood clots (length: 1, 2, 3, 4, 5, and 10 cm, n=1 to 3, 14 monkeys in total) into the internal carotid artery of male cynomolgus monkeys. Digital subtraction angiography (DSA) and neurologic deficit observation were performed pre-; immediately after (DSA only); and 1, 3, 6, and 24 h after embolization, and the relationship between clot length, neurologic deficits, and cerebral infarction was assessed. RESULTS: DSA confirmed MCA occlusion in all animals after the clot injection. Recanalization of the MCA was observed within 6 h post-embolization in animals with shorter clots (≤3 cm). Neurologic deficits were evident in animals with MCA occlusion and correlated with the clot length. Larger clots (≥5 cm) led to permanent MCA occlusion, significant neurologic deficits, and extensive cerebral infarction. Histopathological examination revealed ischemic damage in brain regions corresponding to the infarcted areas. CONCLUSION: Clot length is critical in determining the extent of neurologic dysfunction and cerebral infarction, with larger clots producing more severe outcomes. Furthermore, the minimum clot length required for model creation is 5 cm.

Aneurysm of Petrous and Cavernous Parts of the Internal Carotid Artery: A Case Report.

Internal carotid artery (ICA) aneurysms are rare but they can cause high morbidity and mortality. Although these aneurysms are usually asymptomatic, they can reach huge sizes and compress the surrounding neurovascular structures. Patients typically present with neurologic symptoms due to cranial nerve compression. If they rupture, they can lead to massive epistaxis and autorage. In physical examination, pulsatile mass in the middle ear or nasal cavity can be seen. If there is a clinical suspicion of an ICA aneurysms, diagnostic radiological imaging should be performed before the surgical procedure or biopsy. Cerebral digital subtraction angiography (DSA) should be performed for definitive diagnosis. After diagnosis, appropriate endovascular or open intervention should be performed. In this case report, we present a 48-year-old female patient with severe epistaxis complaint due to an ICA aneurysm. This report aims to present this case and review the current literature.

Semi-automatic computed tomography angiography quantification assessment is an alternative method to digital subtraction angiography in intracranial stenosis: a multicenter study.

Background: The recent randomized controlled trials studying intracranial atherosclerotic stenosis (ICAS) have used digital subtraction angiography (DSA) to quantify stenosis and enroll patients. However, some disadvantages of DSA such as invasive features, contrast agent overuse, and X-ray radiation overexposure, were not considered in these studies. This study aimed to explore whether computed tomography angiography (CTA) with semi-automatic analysis could be an alternative method to DSA in quantifying the absolute stenotic degree in clinical trials. Methods: Patients with 50-99% ICAS were consecutively screened, prospectively enrolled, and underwent CTA and DSA between March 2021 and December 2021 at 6 centers. This study was registered at www.chictr.org.cn (ChiCTR2100052925). The absolute stenotic degree of ICAS on CTA with semi-automatic analysis was calculated by several protocols using minimal/maximum/mean diameters of stenosis and reference site from a semi-automatic analysis software. Intraclass correlation coefficient (ICC) was used to evaluate the reliabilities of quantifying stenotic degree on CTA. The optimal protocol for quantifying ICAS on CTA was explored. The agreements of quantifying ICAS in calcified or non-calcified lesions and 50-69% or 70-99% stenosis on CTA and DSA were assessed. Results: A total of 191 participants (58.8±10.7 years; 148 men) with 202 lesions were enrolled. The optimal protocol for quantifying ICAS on CTA was calculated as (1 - the minimal diameter of stenosis/the mean diameter of reference) × 100% for its highest agreement with DSA [ICC, 0.955, 95% confidence interval (CI): 0.944-0.966, P<0.001]. Among the 202 lesions, 80.2% (162/202) exhibited severe stenosis on DSA. The accuracy of CTA in detecting severe ICAS was excellent (sensitivity =95.1%, positive predictive value =98.1%). The agreements between DSA and CTA in non-calcified lesions (ICC, 0.960 vs. 0.849) and severe stenosis (ICC, 0.918 vs. 0.841) were higher than those in calcified lesions and moderate stenosis. Conclusions: CTA with semi-automatic analysis demonstrated an excellent agreement with DSA in quantifying ICAS, making it promising to replace DSA for the measurement of absolute stenotic degree in clinical trials.

Comparative diagnostic efficacy of cranial CT, CTA, and DSA in subarachnoid hemorrhage management: A systematic review and meta-analysis.

INTRODUCTION: Subarachnoid hemorrhage (SAH) is a critical medical condition associated with high morbidity and mortality rates. Timely and accurate diagnosis is crucial for optimal patient outcomes. Cranial computed tomography (CT), computed tomography angiography (CTA), and digital subtraction angiography (DSA) are commonly used imaging modalities for diagnosing SAH, but their comparative diagnostic efficacy remains debated. METHODS: A systematic review and meta-analysis was conducted to evaluate the diagnostic performance of cranial CT, CTA, and DSA in identifying SAH. PubMed, Google scholar, Cochrane Library databases were searched for relevant studies published up to January 2024. Pooled sensitivity, specificity, and the summary receiver operating characteristic (SROC) curve were calculated using Review Manager 5.4. RESULTS: A total of 31 studies involving 10,287 patients were included in the analysis. The pooled sensitivity of cranial CT for detecting SAH was 94.7 % (95 % Confidence Interval, CI) with a specificity of 98.3 % (95 % CI). CTA demonstrated a pooled sensitivity of 94.1 % (95 % CI) and specificity of 93.4 % (95 % CI). DSA showed a pooled sensitivity of 87.7 % (95 % CI) and specificity of 95.8 % (95 % CI). The SROC curve demonstrated discriminatory ability for all modalities. CONCLUSION: Cranial CT, CTA, and DSA are valuable imaging modalities for diagnosing SAH, with high sensitivity and specificity. Cranial CT serves as an initial screening tool, while CTA offers superior sensitivity in detecting aneurysmal SAH. DSA remains essential in specific clinical scenarios. Further prospective studies are needed to validate these findings and refine diagnostic guidelines for SAH.