Epidemiology, Pathophysiology, and Imaging of Atherosclerotic Intracranial Disease.

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of stroke worldwide. Among people with stroke, those of East Asia descent and non-White populations in the United States have a higher burden of ICAD-related stroke compared with Whites of European descent. Disparities in the prevalence of asymptomatic ICAD are less marked than with symptomatic ICAD. In addition to stroke, ICAD increases the risk of dementia and cognitive decline, magnifying ICAD societal burden. The risk of stroke recurrence among patients with ICAD-related stroke is the highest among those with confirmed stroke and stenosis ≥70%. In fact, the 1-year recurrent stroke rate of >20% among those with stenosis >70% is one of the highest rates among common causes of stroke. The mechanisms by which ICAD causes stroke include plaque rupture with in situ thrombosis and occlusion or artery-to-artery embolization, hemodynamic injury, and branch occlusive disease. The risk of stroke recurrence varies by the presumed underlying mechanism of stroke, but whether techniques such as quantitative magnetic resonance angiography, computed tomographic angiography, magnetic resonance perfusion, or transcranial Doppler can help with risk stratification beyond the degree of stenosis is less clear. The diagnosis of ICAD is heavily reliant on lumen-based studies, such as computed tomographic angiography, magnetic resonance angiography, or digital subtraction angiography, but newer technologies, such as high-resolution vessel wall magnetic resonance imaging, can help distinguish ICAD from stenosing arteriopathies.

Diagnostic Performance of Carotid Ring Sign on CT-Angiography in Internal Carotid True Occlusion.

BACKGROUND: To differentiate between pseudo occlusion (PO) and true occlusion (TO) of internal carotid artery (ICA) is important in thrombectomy treatment planning for patients with acute ischemic stroke. Although delayed contrast filling has been differentiated carotid PO from TO, its application has been limited by the implementations of multiphasic computed tomography angiography. In this study, we hypothesized that carotid ring sign, which is readily acquired from single-phasic CTA, can sufficiently differentiate carotid TO from PO. METHODS: One thousand four hundred and twenty patients with anterior circulation stroke receiving endovascular therapy were consecutively recruited through a hospital- and web-based registry. Two hundred patients with nonvisualization of the proximal ICA were included in the analysis after a retrospective screening. Diagnosis of PO or TO of the cervical segment of ICA was made based on digital subtraction angiography. Diagnostic performances of carotid ring sign on arterial-phasic CTA and delayed contrast filling on multiphasic computed tomography angiography were evaluated and compared. RESULTS: One-hundred twelve patients had ICA PO and 88 had TO. Carotid ring sign was more common in patients with TO (70.5% versus 6.3%; P<0.001), whereas delayed contrast filling was more common in PO (94.9% versus 7.7%; P<0.001). The sensitivity and specificity of carotid ring sign in diagnosing carotid TO were 0.70 and 0.94, respectively, whereas sensitivity and specificity of delayed contrast filling was 0.95 and 0.92 in judging carotid PO. CONCLUSIONS: Carotid ring sign is a potent imaging marker in diagnosing ICA TO. Carotid ring sign could be complementary to delayed contrast filling sign in differentiating TO from PO, in particular in centers with only single-phasic CTA.

Knowledge-Augmented Deep Learning for Segmenting and Detecting Cerebral Aneurysms With CT Angiography: A Multicenter Study.

Background Deep learning (DL) could improve the labor-intensive, challenging processes of diagnosing cerebral aneurysms but requires large multicenter data sets. Purpose To construct a DL model using a multicenter data set for accurate cerebral aneurysm segmentation and detection on CT angiography (CTA) images and to compare its performance with radiology reports. Materials and Methods Consecutive head or head and neck CTA images of suspected unruptured cerebral aneurysms were gathered retrospectively from eight hospitals between February 2018 and October 2021 for model development. An external test set with reference standard digital subtraction angiography (DSA) scans was obtained retrospectively from one of the eight hospitals between February 2022 and February 2023. Radiologists (reference standard) assessed aneurysm segmentation, while model performance was evaluated using the Dice similarity coefficient (DSC). The model's aneurysm detection performance was assessed by sensitivity and comparing areas under the receiver operating characteristic curves (AUCs) between the model and radiology reports in the DSA data set with use of the DeLong test. Results Images from 6060 patients (mean age, 56 years ± 12 [SD]; 3375 [55.7%] female) were included for model development (training: 4342; validation: 1086; and internal test set: 632). Another 118 patients (mean age, 59 years ± 14; 79 [66.9%] female) were included in an external test set to evaluate performance based on DSA. The model achieved a DSC of 0.87 for aneurysm segmentation performance in the internal test set. Using DSA, the model achieved 85.7% (108 of 126 aneurysms [95% CI: 78.1, 90.1]) sensitivity in detecting aneurysms on per-vessel analysis, with no evidence of a difference versus radiology reports (AUC, 0.93 [95% CI: 0.90, 0.95] vs 0.91 [95% CI: 0.87, 0.94]; P = .67). Model processing time from reconstruction to detection was 1.76 minutes ± 0.32 per scan. Conclusion The proposed DL model could accurately segment and detect cerebral aneurysms at CTA with no evidence of a significant difference in diagnostic performance compared with radiology reports. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Payabvash in this issue.

A procedural step analysis of radiation exposure in fenestrated endovascular aortic repair.

OBJECTIVE: Radiation exposure during complex endovascular aortic repair may be associated with tangible adverse effects in patients and operators. This study aimed to identify the steps of highest radiation exposure during fenestrated endovascular aortic repair (FEVAR) and to investigate potential intraoperative factors affecting radiation exposure. METHODS: Prospective data of 31 consecutive patients managed exclusively with four-fenestration endografts between March 1, 2020, and July 1, 2022 were retrospectively analyzed. Leveraging the conformity of the applied technique, every FEVAR operation was considered a combination of six overall stages composed of 28 standardized steps. Intraoperative parameters, including air kerma, dose area product, fluoroscopy time, and number of digital subtraction angiographies (DSAs) and average angulations were collected and analyzed for each step. RESULTS: The mean procedure duration and fluoroscopy time was 140 minutes (standard deviation [SD], 32 minutes), and 40 minutes (SD, 9.1 minutes), respectively. The mean air kerma was 814 mGy (SD, 498 mGy), and the mean dose area product was 66.8 Gy cm2 (SD, 33 Gy cm2). The percentage of air kerma of the entire procedure was distributed throughout the following procedure stages: preparation (13.9%), main body (9.6%), target vessel cannulation (27.8%), stent deployment (29.1%), distal aortoiliac grafting (14.3%), and completion (5.3%). DSAs represented 23.0% of the total air kerma. Target vessel cannulation and stent deployment presented the highest mean lateral angulation (67 and 63 degrees, respectively). Using linear regression, each minute of continuous fluoroscopy added 18.9 mGy of air kerma (95% confidence interval, 17.6-20.2 mGy), and each DSA series added 21.1 mGy of air kerma (95% confidence interval, 17.9-24.3 mGy). Body mass index and lateral angulation were significantly associated with increased air kerma (P < .001). CONCLUSIONS: Cannulation of target vessels and bridging stent deployment are the steps requiring the highest radiation exposure during FEVAR cases. Optimized operator protection during these steps is mandatory.

Treatment strategy for splenic artery aneurysms and novel classification based on imaging.

OBJECTIVE: The incidence of splenic artery aneurysms (SAAs) has increased with advances in imaging techniques, necessitating a comprehensive classification to guide treatment strategies. This study aims to propose a novel classification system for SAAs based on aneurysm characteristics and to review treatment outcomes at our center. METHODS: This retrospective study included 113 patients with SAAs admitted to Peking Union Medical College Hospital from January 2019 to December 2023, assessed using computed tomography angiography or digital subtraction angiography. A new classification system was devised based on the aneurysm location, morphology, integrity, and parent artery anatomy. Treatment strategies were determined based on these characteristics, with interventions ranging from endovascular therapy to laparoscopic and open surgery. Patients were followed up after the intervention to assess mortality, complications, reinterventions, and aneurysm-related outcomes. RESULTS: The study cohort of 113 patients with 127 SAAs had a predominance of female patients (63.7%) and a mean age of 52.7 years. The SAAs were classified into five types, with type I being the most common. The intervention techniques varied across types, with sac embolization, covered stent implantation, and artery embolization being the most frequently used. The overall technical success rate was 94.7%, with perioperative complication and reintervention rates of 25.0% and 0.9%, respectively, and no deaths within 30 days after the intervention. The median follow-up duration was 21 months, with overall complications rate of 3.5% and no aneurysm-related complications or deaths. CONCLUSIONS: The proposed classification system effectively guides the selection of treatment strategies for SAAs, incorporating key anatomical and morphological features. This system facilitated high technical success and low complication rates, underscoring the importance of tailored techniques in managing SAAs.

Digital subtraction angiography-guided pancreatic arterial infusion of GEMOX chemotherapy in advanced pancreatic adenocarcinoma: a phase II, open-label, randomized controlled trial comparing with intravenous chemotherapy.

BACKGROUND: Advanced pancreatic adenocarcinoma lacks effective treatment options, and systemic gemcitabine-based chemotherapy offers only marginal survival benefits at the cost of significant toxicities and adverse events. New therapeutic options with better drug availability are warranted. This study aims to evaluate the safety and efficacy of digital subtraction angiography (DSA)-guided pancreatic arterial infusion (PAI) versus intravenous chemotherapy (IVC) using the gemcitabine and oxaliplatin (GEMOX) regimen in unresectable locally advanced or metastatic pancreatic cancer (PC) patients. MATERIALS AND METHODS: This study prospectively enrolled 51 eligible treatment-naive patients with unresectable PC to receive GEMOX treatment via PAI or IVC (1:1 ratio randomization) from December 2015 to December 2019. Cycles were repeated monthly, and each process consisted of two treatments administered bi-weekly. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), 1-year survival, 6-month survival, tumor-site subgroup survival, and incidences of adverse events were compared. RESULTS: The median OS of the PAI and IVC groups were 9.93 months and 10.07 months, respectively (p = 0.3049). The median PFS of the PAI and IVC groups were 5.07 months and 4.23 months (p = 0.1088). No significant differences were found in the ORR (11.54% vs. 4%, p = 0.6312), DCR (53.85% vs. 44%, p = 0.482), and 1-year OS rate (44% vs. 20.92%, p = 0.27) in PAI and IVC groups. The 6-month OS rate was significantly higher in the PAI group (100%) than in the IVC group (83.67%) (p = 0.0173). The median OS of patients in PAI group with pancreatic head and neck tumors were significantly higher than those of body and tail tumors (12.867 months vs. 9 months, p = 0.0214). The incidences of hematologic disorders, liver function disorders, and digestive disorders in the IVC group were higher than in the PAI group (p < 0.05). CONCLUSION: GEMOX PAI therapy presented a higher 6-month OS rate and fewer adverse events than IVC in advanced pancreatic adenocarcinoma patients. Those with pancreatic head and neck tumors may yield a superior treatment outcome from PAI treatment. TRIAL REGISTRATION NUMBER: NCT02635971. DATE OF REGISTRATION: 21/12/2015.

Enhanced vessel wall magnetic resonance imaging in the follow-up of intracranial aneurysms treated with flow diversion.

OBJECTIVE: This study aimed to compare the efficacy of enhanced 3D T1-weighted black-blood fast-spin-echo vessel wall magnetic resonance imaging (eVW-MRI) and time-of-flight magnetic resonance angiography (TOF MRA) for follow-up evaluation of aneurysms treated with flow diversion (FD). METHODS: Our study enrolled 77 patients harboring 84 aneurysms treated with FD. Follow-up was by MRI (eVW-MRI and TOF MRA) and digital subtraction angiography (DSA). Two radiologists, blinded to DSA examination results, independently evaluated the images of aneurysm occlusion and parent artery patency using the Kamran-Byrne Scale. Interobserver diagnostic agreement and intermodality diagnostic agreement were acquired. Pretreatment and follow-up aneurysm wall enhancement (AWE) patterns were collected. RESULTS: Based on the Kamran-Byrne Scale, the intermodality agreement between eVW-MRI and DSA was better than TOF MRA versus DSA for aneurysm remnant detection (weighted ĸ = 0.891 v. 0.553) and parent artery patency (ĸ = 0.950 v. 0.221). Even with the coil artifact, the consistency of eVW-MRI with DSA for aneurysm remnant detection was better than that of TOF MRA (weighted ĸ = 0.891 v. 0.511). The artifact of adjunctive coils might be more likely to affect the accuracy in evaluating parent artery patency with TOF MRA than with eVW-MRI (ĸ = 0.077 v. 0.788). The follow-up AWE patterns were not significantly associated with pretreatment AWE patterns and aneurysm occlusion. CONCLUSIONS: The eVW-MRI outperforms TOF MRA as a reliable noninvasive and nonionizing radioactive imaging method for evaluating aneurysm remnants and parent artery patency after FD. The significance of enhancement patterns on eVW-MRI sequences needs more exploration. CLINICAL RELEVANCE STATEMENT: The application of enhanced vessel wall magnetic resonance imaging has proven to be a promising tool to depict aneurysm remnant and parent artery stenosis in order to tailor the antiplatelet therapy strategy in patients after flow diversion. KEY POINTS: • Enhanced vessel wall magnetic resonance imaging has an emerging role in depicting aneurysm remnant and parent artery patency after flow diversion. • With or without the artifact from adjunctive coils, enhanced vessel wall magnetic resonance imaging was better than TOF MRA in detecting aneurysm residual and parent artery stenosis by using DSA imaging as the standard. • Enhanced vessel wall magnetic resonance imaging holds potential to be used as an alternative to DSA for routine aneurysm follow-up after flow diversion.

Angiography-based hemodynamic features predict recurrent ischemic events after angioplasty and stenting of intracranial vertebrobasilar atherosclerotic stenosis.

OBJECTIVES: To assess the predictive value of hemodynamic features for stroke relapse in patients with intracranial vertebrobasilar atherosclerotic stenosis treated with percutaneous transluminal angioplasty and stenting (PTAS) using quantitative digital subtraction angiography (q-DSA). METHODS: In this retrospective longitudinal study, patients with intracranial vertebrobasilar atherosclerotic stenosis and who underwent PTAS treatment between January 2012 and May 2020 were enrolled. The q-DSA assessment was performed before and after PTAS. ROIs 1-4 were placed along the vertebral artery, proximal and distal basilar artery, and posterior cerebral artery; ROIs 5-8 were in 5 mm and 10 mm proximal and distal to the lesion, respectively. Relative time to peak (rTTP) was defined as the difference in TTP between ROIs. Cox regression analyses were performed to determine risk factors for recurrent stroke. RESULTS: A total of 137 patients (mean age, 62 years ± 10 [standard deviation], 83.2% males) were included, and 26 (19.0%) patients had stroke relapse during follow-up (median time of 42.6 months [interquartile range, 19.7-60.7]). Preprocedural rTTP4-1 (adjusted hazard ratio (HR) = 2.270; 95% CI 1.371-3.758; p = 0.001) and preprocedural rTTP8-5 (adjusted HR = 0.240; 95% CI 0.088-0.658; p = 0.006) were independently associated with the recurrent stroke. These hemodynamic parameters provided an incremental prognostic value for stroke relapse (AUC, 0.817 [0.704-0.931]; the net reclassification index, 0.431 [0.057-0.625]; and the integrated discrimination index, 0.140 [0.035-0.292]). CONCLUSIONS: In patients with intracranial vertebrobasilar atherosclerosis treated with PTAS, preprocedural prolonged TTP of the target vessel and shortened trans-stenotic TTP difference were associated with stroke relapse. Q-DSA-defined hemodynamic parameters provided incremental predictive value over conventional parameters for stroke recurrence. CLINICAL RELEVANCE STATEMENT: Quantitative DSA analysis enables intuitive observation and semi-quantitative evaluation of peri-therapeutic cerebral blood flow. More importantly, quantitative DSA-defined hemodynamic parameters have the potential for risk stratification of patients with intracranial atherosclerotic stenosis. KEY POINTS: Semi-quantitative angiography-based parameters can reflect pre- and postprocedural subtle changes in blood flow in patients with intracranial atherosclerotic stenosis. Although angioplasty procedures can significantly improve blood flow status, patients with more restricted baseline blood flow still show a higher risk of stroke recurrence. Angiography-based hemodynamic features possess prognostic value and can serve as clinical markers to assess stroke risk of patients with intracranial atherosclerotic stenosis.

Quantification of Iliac Arterial Blood Velocity in Stenotic Phantom and Porcine Models Using Quantitative Digital Subtraction Angiography.

PURPOSE: To assess the feasibility of using quantitative digital subtraction angiography (qDSA) to quantify arterial velocity in phantom and porcine stenotic iliac artery models. MATERIALS AND METHODS: Varying degrees of stenoses (mild, <50%; moderate, 50%-70%; and severe, >70%) were created in a silicone iliac artery phantom using vessel loops. Two-dimensional digital subtraction angiography (DSA) was performed, with velocities calculated using qDSA. qDSA velocities were compared with flow rates and velocities measured with an ultrasonic flow probe. Two-dimensional DSAs of the common and external iliac arteries were then performed in 4 swine (mean weight, 63 kg) before and after a severe stenosis (>70%) was created in the iliac artery using 3-0 silk suture. Peak systolic velocities on pulsed wave Doppler ultrasound (US) before and after stenosis creation were correlated with the qDSA velocities. Pearson correlation, linear regression, and analysis of variance were used for analysis. RESULTS: In the phantom study, ultrasonic probe velocities positively correlated with downstream qDSA (r = 0.65; P < .001) and negatively correlated with peristenotic qDSA velocities (r = -0.80; P < .001). In the swine study, statistically significant reductions in external iliac arterial velocity were noted on US and qDSA after stenosis creation (P < .05). US and qDSA velocities strongly correlated for all flow states with both 50% and 100% contrast concentrations (r = 0.82 and r = 0.74, respectively), with an estimated US-to-qDSA ratio of 1.3-1.5 (P < .001). qDSA velocities with 50% and 100% contrast agent concentrations also strongly correlated (r = 0.78; P < .001). CONCLUSIONS: In both phantom and swine stenosis models, changes in iliac arterial velocity could be quantified with qDSA, which strongly correlated with standard-of-care US.

Quantitative 2-Dimensionsal Digital Subtraction Venography for Venous Interventions: Validation in Phantom and In Vivo Porcine Models.

PURPOSE: To determine the feasibility of using a 2-dimensional quantitative digital subtraction venography (qDSV) technique that employs a temporally modulated contrast medium injection to quantify blood velocity in phantom, normal, and stenotic porcine iliac vein models. MATERIALS AND METHODS: Blood velocity was calculated using qDSV following temporally modulated pulsed injections of iodinated contrast medium and compared with Doppler ultrasound (US) measurements (phantom, in-line sensor; in vivo, diagnostic linear probe). Phantom evaluation was performed in a compliant polyethylene tube phantom with simulated venous flow. In vivo evaluation of qDSV was performed in normal (n = 7) and stenotic (n = 3) iliac vein models. Stenoses were created using endovenous radiofrequency ablation, and blood velocities were determined at baseline, after stenosis, after venoplasty, and after stent placement. RESULTS: In the phantom model, qDSV-calculated blood velocities (12-50 cm/s) had very strong correlations with US-measured velocities (13-51 cm/s) across a range of baseline blood velocities and injection protocols (slope, 1.01-1.13; R2 = 0.96-0.99). qDSV velocities were similar to US velocities regardless of injection method: (a) custom injector, (b) commercial injector, or (c) hand injection. In the normal in vivo model, qDSV-calculated velocities (5-18 cm/s) had strong correlation (slope, 1.22; R2 = 0.90) with US-measured velocities (3-20 cm/s). In the stenosis model, blood velocities at baseline, after stenosis, after venoplasty, and after stent placement were similar on qDSV and US at all time points. CONCLUSIONS: Venous blood velocity was accurately quantified in a venous phantom and in vivo porcine models using qDSV. Intraprocedural changes in porcine iliac vein blood velocity were quantified with qDSV after creation of a stenosis and subsequently treating it with venoplasty and stent placement.

Collateral Round Ligament Arterial Supply of Placenta Accreta Spectrum and Considerations for Prophylactic Balloon Occlusion Catheter Placement.

Internal iliac artery (IIA) balloon occlusion catheters have been commonly inserted to decrease the risk of postpartum hemorrhage in placenta accreta spectrum disorders; however, there has been mixed success in clinical studies. Placement of an infrarenal aortic balloon has shown more consistent effectiveness in recent studies. A possible reason for this is collateral arterial supply to the placenta from external iliac artery branches. Retrospective chart review was conducted of angiography images during prophylactic IIA balloon occlusion catheter insertion over a 7-year period. Sixty-two individual cases were identified. Digital subtraction angiography (DSA) was performed in 32 (52%) cases, and 20 (62%) showed collateral blood supply from branches of the external iliac arteries, namely the round ligament artery. In conclusion, a high proportion of placenta accreta spectrum cases have arterial blood supply from branches of the external iliac artery, which may explain the discrepancy in effectiveness seen between IIA and infrarenal aortic sites of balloon occlusion catheter placement.

Measurement of the Tumor-to-Normal Ratio for Radioembolization of Hepatocellular Carcinoma: A Prospective Study Comparing 2-Dimensional Perfusion Angiography, Technetium-99m Macroaggregated Albumin, and Yttrium-90 SPECT/CT.

PURPOSE: To calculate the preradioembolic tumor-to-normal (T:N) ratio in hepatocellular carcinoma (HCC) using 2-dimensional (2D) perfusion angiography and compare it with that calculated using technetium-99m macroaggregated albumin (99mTc MAA) single-photon emission computed tomography (SPECT)/computed tomography (CT). MATERIALS AND METHODS: This prospective single-arm study enrolled 15 participants with HCC who underwent 2D perfusion angiography immediately before the enrollment and with the microcatheter located at the same location as 99mTc MAA injection, after which SPECT/CT was performed. Quantitative digital subtraction angiography was used to calculate the area under the curve for the tumor and normal hepatic parenchyma and subsequently calculate the T:N ratio. The T:N ratio was calculated from the 99mTc MAA SPECT/CT and post-yttrium-90 bremsstrahlung SPECT/CT using dosimetry software. RESULTS: The mean participant age was 64.1 years ± 9.8, and the study included 14 (93%) men and 1 (7%) woman. The mean tumor size was 4.1 cm (SD ± 2.4), and all participants received segmental treatments with glass microspheres. The mean T:N ratio calculated by 99mTc MAA SPECT/CT was 2.28 (SD ± 0.89) vs 2.25 (SD ± 0.99) calculated by 2D perfusion angiography (P = .45). For the 13 participants who underwent selective internal radiation therapy (transarterial radioembolization), there was no significant difference between the T:N ratios calculated by 2D perfusion angiography and post-90Y SPECT/CT (2.25 [SD ± 1.05] vs 1.91 [SD ± 0.39]; P = .12). CONCLUSIONS: The T:N ratio calculated by 2D perfusion angiography correlated well with that calculated by 99mTc MAA SPECT/CT.

The Influence of Embolization of Internal Carotid Artery Aneurysms on Arterial Tortuosity: A Prospective Cohort Study.

PURPOSE: To measure changes in quantitative tortuosity descriptors of the internal carotid artery (ICA) after intracranial aneurysm embolization, and to determine possible factors associated with changes in tortuosity. MATERIALS AND METHODS: An analysis of 52 patients with embolized intracranial aneurysms was performed. ICA tortuosity was assessed by digital subtraction angiograms obtained prior to the embolization and after the first follow-up examination. For each patient, tortuosity descriptors were calculated: relative length (RL), sum of angle metrics (SOAM), triangular index, product of angle distance (PAD), and inflection count metric (ICM). To represent changes in tortuosity for each descriptor, delta (Δ) value was defined as value of the descriptor prior to embolization minus value of the descriptor on follow-up examination. RESULTS: In a median follow-up of 14 months, no statistically significant changes in tortuosity were observed on the nonembolized side. On the embolized side, SOAM (2.89 [SD ± 0.92] vs 2.38 [SD ± 0.94]; P < .001), PAD (5.01 [SD ± 1.83] vs 3.95 [SD ± 1.72]; P < .001), and ICM (12.18 [SD ± 4.55] vs 9.76 [SD ± 4.04]; P = .006) were significantly higher after embolization than before embolization. Median ΔRL (-0.02 [-0.045 to 0.002] vs -0.01 [-0.02 to 0.003]; P = .003), ΔPAD (0.84 [0.30-1.82] vs 0.10 [-0.001 to 1.10]; P < .001), and ΔICM (2.05 [0.42-3.50] vs 0.27 [0.02-2.16]; P = .004) were significantly higher on the embolized side. Tortuosity correlated with elapsed time after embolization. CONCLUSIONS: Tortuosity of the ipsilateral ICA increased after intracranial aneurysm embolization.

Contrast-induced encephalopathy after an embolization procedure for a cerebral aneurysm in a female with subarachnoid hemorrhage: a case report.

BACKGROUND: Contrast-induced encephalopathy (CIE) is a rare complication during or after angiography, usually transient and reversible. CIE diagnosis is challenging due to the absence of no formal diagnostic criteria. CIE can mimic stroke symptoms, including visual disturbances, seizures, confusion, coma, and focal neurological deficits. This case reports neurological deficit reversal in a CIE patient due to the embolization of an intracranial aneurysm, the second angiographic procedure in six days. CASE PRESENTATION: A 77-year-old woman was admitted to the hospital for headaches. The cerebral computed tomography (CT) scan indicated a subarachnoid hemorrhage. The first digital subtraction angiography (DSA) identified an aneurysm of 4 mm ∗ 3 mm in size in the M1 segment of the right middle cerebral artery (MCA). Then, embolization surgery was performed for the cerebral aneurysm, which was successful. However, the patient had post-operative headaches, slurred speech, epilepsy, limb weakness, and delirium post-procedure. The non-contrast cerebral CT indicated widespread edema in the right cerebral hemisphere. The patient was diagnosed with CIE and treated with symptomatic supportive therapy. Eventually, the patient's neurological deficits and cerebral edema improved significantly. CONCLUSIONS: The current case emphasized the importance of early diagnosis and symptomatic treatment of CIE. Thus, CIE should be the first consideration during the differential diagnosis of a patient having acute neurological impairment after repeated DSA.

Evaluating the diagnostic performance of non-contrast magnetic resonance angiography sequences in the pre-procedural comprehensive analysis of direct carotid cavernous fistula.

PURPOSE: Endovascular treatment of direct carotid cavernous fistula (DCCF) requires invasive diagnostic cerebral angiography for diagnosis and planning; however, a less invasive modality like magnetic resonance angiography (MRA) can be useful, especially in high-risk cases. This single-centre study evaluated a newer MR angiography (MRA) sequence, silent MRA and the traditional time of flight (TOF) MRA for pre-procedural treatment planning of DCCF. METHODS: All consecutive DCCF patients who underwent TOF, silent MRA and diagnostic cerebral angiography were included in the study. Angiographic features like rent size, location, draining veins and collateral communicating arteries were analysed and compared between the two MRA sequences, with digital subtraction angiography (DSA) as the gold standard. RESULTS: Fifteen patients were included in the study. TOF MRA exhibited better sensitivity (76.9% vs 69.2%) in identifying the rent location, correctly pinpointing the location in 93.3% compared to 73.3% with silent MRA. Both MRA sequences showed good agreement with DSA for primary sac and rent size. TOF MRA correctly identified 86.2% of 210 total venous structures compared to 96% by silent MRA. Silent MRA demonstrated higher sensitivity (90% vs 76%) and accuracy (87.69 vs 94.36) in visualisation of involved veins compared to TOF MRA. CONCLUSION: Arterial characteristics of DCCF like rent location and rent size were better assessed by TOF MRA. Although both MRA identified venous features, silent MRA correlated better with DSA irrespective of the size and proximity to the site of the fistula. Combining both sequences can evaluate various angioarchitectural features of DCCF useful for therapeutic planning.

Exploration of postural effects on the external jugular and diploic venous system using upright computed tomography scanning.

PURPOSE: Few studies have investigated the influence of posture on the external jugular and diploic venous systems in the head and cranial region. In this study, we aimed to investigate the effects of posture on these systems using upright computed tomography (CT) scanning. METHODS: This study retrospectively analysed an upright CT dataset from a previous prospective study. In each patient, the diameters of the vessels in three external jugular tributaries and four diploic veins were measured using CT digital subtraction venography in both supine and sitting positions. RESULTS: Amongst the 20 cases in the original dataset, we eventually investigated 19 cases due to motion artifacts in 1 case. Compared with the supine position, most of the external jugular tributaries collapsed, and the average size significantly decreased in the sitting position (decreased by 22-49% on average). In contrast, most of the diploic veins, except the occipital diploic veins, tended to increase or remain unchanged (increased by 12-101% on average) in size in the sitting position compared with the supine position. However, the changes in the veins associated with this positional shift were not uniform; in approximately 5-30% of the cases, depending on each vein, an opposite trend was observed. CONCLUSION: Compared to the supine position, the contribution of external jugular tributaries to head venous drainage decreased in the sitting position, whilst most diploic veins maintained their contribution. These results could enhance our understanding of the physiology and pathophysiology of the head region in upright and sitting positions.

Evaluation of the contribution of individual arteries to the cerebral blood supply in patients with Moyamoya angiopathy: comparison of vessel-encoded arterial spin labeling and digital subtraction angiography.

PURPOSE: Vessel-encoded arterial spin labeling (VE-ASL) is able to provide noninvasive information about the contribution of individual arteries to the cerebral perfusion. The aim of this study was to compare VE-ASL to the diagnostic standard digital subtraction angiography (DSA) with respect to its ability to visualize vascular territories. METHODS: In total, 20 VE-ASL and DSA data sets of 17 patients with Moyamoya angiopathy with and without revascularization surgery were retrospectively analyzed. Two neuroradiologists independently assessed the agreement between VE-ASL and DSA using a 4-point Likert scale (no- very high agreement). Additionally, grading of the vascular supply of subterritories (A1-A2, M1-M6) on the VE-ASL images and angiograms was performed. The intermodal agreement was calculated for all subterritories in total and for the subdivision into without and after revascularization (direct or indirect bypass). RESULTS: There was a very high agreement between the VE-ASL and the DSA data sets (median = 1, modus = 1) with a substantial inter-rater agreement (kw = 0.762 (95% CI 0.561-0.963)). The inter-modality agreement between VE-ASL and DSA in vascular subterritories was almost perfect for all subterritories (k = 0.899 (0.865-0.945)), in the subgroup of direct revascularized subterritories (k = 0.827 (0.738-0.915)), in the subgroup of indirect revascularized subterritories (k = 0.843 (0.683-1.003)), and in the subgroup of never revascularized subterritories (k = 0.958 (0.899-1.017)). CONCLUSION: Vessel-encoded ASL seems to be a promising non-invasive method to depict the contributions of individual arteries to the cerebral perfusion before and after revascularization surgery.

Embolization techniques of spontaneous direct carotid-cavernous fistulae: a single-center experience.

PURPOSE: Spontaneous direct carotid-cavernous fistula (CCF) are usually caused by a ruptured carotid cavernous aneurysm. We studied treatment of spontaneous direct CCFs in a single-center cohort of a high-volume tertiary referral center, reporting anatomical details, technical approaches of treatment, and outcomes. METHODS: Adult patients with a spontaneous direct CCF treated between 2010-2022 with follow-up MRI and/or DSA imaging available were retrospectively analyzed. We studied age, sex, clinical presentation, angiographic findings, treatment techniques, outcomes, and complications. RESULTS: Out of 80 patients with CCFs, twelve patients were treated for a non-traumatic direct CCF (15%) in 13 sessions. Median age was 65 years. Two patients had an underlying connective tissue disorder. In 10 cases, the direct CCF was caused by a ruptured cavernous carotid aneurysm. The direct CCFs were treated by endovascular transarterial embolization (10 cases), transvenous embolization (1 case), or surgery (1 case). Selective closure of the shunt was possible in 10 patients. Two patients were treated with parent vessel occlusion (PVO; one endovascular; one surgical, with bypass). Complications occurred in 2 / 12 patients (17%), with permanent morbidity in two patients (17%): trigeminal neuralgia after PVO and new infarct after surgical PVO and bypass. Selective closure of CCF resulted in no morbidity. There was no mortality in our series. CONCLUSION: Spontaneous direct CCFs are caused by rupture of a cavernous carotid aneurysm in most cases. Selective closure of the shunt, usually feasible transarterially with coils, achieves good results. Reconstructive endovascular techniques are preferred to minimize treatment related neurological complications.

The usefulness of super-selective arterial spin labeling for postoperative evaluation of pediatric moyamoya disease: technical note.

Moyamoya disease is characterized by progressive internal carotid artery (ICA) occlusion. Extracranial-intracranial bypass surgery is effective, particularly in pediatric patients; imaging plays a crucial role in evaluating intracranial perfusion pre- and post-surgery. Arterial spin labeling (ASL) is a magnetic resonance technique employed for noninvasive, whole-brain perfusion assessment by magnetically labeling inflowing blood. However, ASL cannot evaluate the territories and development of each vessel perfusion compared with digital subtraction angiography (DSA). Recently, super-selective ASL (SS-ASL) has been developed, performing pinpoint labeling on a specific artery at a time, and offering a tomographic view that distinctly displays blood supply areas for each vessel. Unlike DSA, SS-ASL is noninvasive and can be repeatedly performed in pediatric patients. In conclusion, SS-ASL is useful for evaluating bypass development over time and understanding the pathophysiology of pediatric moyamoya disease.

Comparative study of non-contrast silent and time-of-flight magnetic resonance angiographic sequences in the evaluation of intracranial dural arteriovenous fistula.

AIM: To compare the performance of two non-contrast magnetic resonance angiography (MRA) sequences, silent MRA and time of flight (TOF) MRA, in the evaluation of intracranial dural arteriovenous fistula (DAVF). MATERIALS AND METHODS: Forty consecutive patients with DAVF were enrolled and evaluated prospectively using silent MRA, TOF MRA, and digital subtraction angiography (DSA). The location, Cognard classification, arterial feeders, and venous drainage were evaluated. The therapeutic strategy and possible route were predicted on both silent and TOF MRA and these were compared with DSA during subsequent endovascular treatment. RESULTS: Sensitivity and accuracy of silent and TOF MRA for localisation (96.4% versus 96% and 96% versus 95%, respectively) and classification (96% versus 94% and 96% versus 93.5%, respectively) were high. Silent MRA showed higher sensitivity than TOF MRA for arterial feeders and draining veins (87% versus 79% and 81.6% versus 67%). This improved to a sensitivity of 96.4% and 89% when prominent feeders were considered. The sensitivity and accuracy were 92.6% and 85.8% for immediate draining veins. Both silent and TOF MRA were accurate for therapeutic planning (96% versus 85%), although silent MRA was more accurate. CONCLUSION: Silent MRA can more reliably evaluate the various angioarchtectural components of DAVF compared to TOF MRA.