Imaging Pattern and the Mechanisms of Postoperative Infarction After Indirect Revascularization in Patients with Moyamoya Disease.

OBJECTIVE: To develop preventive strategies against postoperative infarction after indirect revascularization surgery in patients with moyamoya disease (MMD), we evaluated clinical information, with a specific focus on the imaging pattern of postoperative infarction. METHODS: We retrospectively evaluated 421 surgical procedures performed in 354 (262 pediatric and 159 adult) patients with MMD from April 1991 to March 2021 at our institute. In addition to clinical information, raw images of postoperative infarction were collected and categorized into subtypes by the location of the infarction. RESULTS: Symptomatic and asymptomatic postoperative infarction occurred in 47 and 12 patients (11.1% and 2.6%), respectively, and more than half (51.7%) of these cases of postoperative infarction occurred immediately or the day after the surgery. Cortical infarction around the craniotomy site was the most frequent pattern observed (50/59, 84.8%), and some of these cases seemed to occur under local compression from epidural or subdural hematomas (15/50, 30.0%). Ipsilateral white matter infarctions located in the watershed area (9/59, 15.3%) and contralateral infarctions (3/59, 5.1%) were also observed. Four patients (1.0%) showed sudden occlusions of ipsilateral or contralateral large intracranial arteries immediately after surgery. Postoperative infarction caused permanent neurologic deficits in 7 patients (1.7%), and all included the cortex outside the craniotomy site. CONCLUSIONS: Local cortical irritation, hemodynamic fluctuation, and thromboembolic events were suggested as possible mechanisms of postoperative infarction after indirect revascularization in patients with MMD. Minimizing cortical irritation, maintaining adequate cerebral blood flow, and perioperative antiplatelet agents might decrease the incidence of postoperative infarction.

Endovascular Treatment of Intracranial Kissing Aneurysms: Technical Feasibility and Clinical Outcomes.

BACKGROUND: Kissing aneurysms are situated on the same artery but have separate points of origin. Open surgical strategies for access from opposing directions may be technically problematic. Recent advances in protective devices and coiling techniques have compelled the present study, aimed at technical aspects and procedural outcomes of coil embolization in this setting. METHODS: Data prospectively accruing between May 2001 and May 2020 were systematically reviewed, assessing clinical and morphologic outcomes of coil embolization in 36 patients with 72 kissing aneurysms. RESULTS: Lesions most often involved paraclinoid internal carotid artery (n = 22), followed by anterior communicating artery (n = 7). Single-stage coil embolization of both aneurysms took place in nearly all patients (n = 35). Microcatheter tips for selecting paired aneurysms were usually directed opposite to one another (32 of 36, 88.9%), applying protective devices (i.e., balloons or stents) to 1 or both aneurysms in 21 patients (58.3%). Balloons were placed in 9 patients, often when treating first aneurysms and largely for second aneurysms as well (7 of 9, 77.8%). Stents deployed in 14 patients involved first and second aneurysms equally. Two patients required balloon of stent combinations. No procedure-related morbidity or mortality resulted. In follow-up of 68 aneurysms (mean: 40.2 ± 28.1 months) after coiling, 86.8% (59 of 68) showed sustained complete saccular occlusion. CONCLUSIONS: Strategies for endovascular treatment of kissing aneurysms rely heavily on characteristics that the paired aneurysms display. Properly conducted single-stage coil embolization is a safe and effective method of treating such lesions.

Use of Head and Neck Magnetic Resonance Angiography to Explore Neurological Function Recovery and Impact of Rehabilitation Nursing on Patients with Acute Stroke.

OBJECTIVE: To analyze neurological function recovery and the impact of rehabilitation nursing in patients with cerebral stroke after treatment to aid clinical diagnosis and treatment of cerebral stroke. METHODS: The study comprised 140 patients who were hospitalized in the neurology department for magnetic resonance angiography examination. Patients were divided into a treatment group (70 patients) and a control group (70 patients) based on treatment plan. Digital subtraction angiography was regarded as the gold standard diagnostic examination. In patients in both groups, magnetic resonance angiography features of the M1 segment of the middle cerebral artery and diagnostic specificity and sensitivity were recorded. An activities of daily living score was used to assess neurological function of patients before and after rehabilitation. RESULTS: The activities of daily living scores of patients in both groups increased significantly after treatment (P < 0.05); the scores of patients in the treatment group increased more significantly (P < 0.05). The total effective rate was 89% in the treatment group and 60% in the control group. The difference between the 2 groups was statistically significant (P < 0.05). After treatment, the degree of M1 segment stenosis in both groups was better than before treatment, and the number of collateral circulation branches was increased; the improvements in the treatment group were more significant (P < 0.05). CONCLUSIONS: Rehabilitation nursing could greatly improve the stenosis of blood vessels in patients with acute cerebral stroke and promote the establishment of collateral circulation, thereby effectively enhancing the recovery of neurological function and strengthening the ability of patients to perform activities of daily living.

Follow-up outcomes of intracranial aneurysms treated using braided or laser-cut stents with closed-cell design: a propensity score-matched case-controlled comparison.

BACKGROUND: The impact of various stents on patients with intracranial aneurysms who undergo stent-assisted coiling has been debated. We conducted this study to compare follow-up outcomes of coiling procedures involving braided or laser-cut stents with closed-cell design. A propensity score-matched case-controlled analysis was applied. METHODS: A total of 413 intracranial aneurysms consecutively coiled using laser-cut (n=245) or braided stents (n=168) in procedures performed between September 2012 and June 2017 were eligible for study. Time-of-flight magnetic resonance angiography, catheter angiography, or both were used to gauge occlusive status after coiling. Recanalization was determined by Raymond classification (complete occlusion vs recanalization). A propensity score-matched analysis was conducted, based on probability of stent type in use. RESULTS: Ultimately, 93 coiled aneurysms (22.5%) showed some recanalization (minor, 51; major, 42) during the follow-up period (mean 21.7±14.5 months). Patient gender (P=0.042), hyperlipidemia (P=0.015), size of aneurysm (P=0.004), neck size (P<0.001), type of aneurysm (P<0.001), and packing density (P=0.024) differed significantly by group. Midterm and cumulative recanalization incidence rates in the braided-stent group were initially lower than those of the laser-cut stent group (P=0.009 and P=0.037, respectively) but they did not differ significantly after 1:1 propensity score matching (midterm OR=0.88, P=0.724; cumulative HR=0.91, P=0.758). CONCLUSION: In stent-assisted coiling of intracranial aneurysms, laser-cut and braided stent groups produced similar outcomes in follow-up. Consequently, product selection may hinge on suitability for deployment rather than anticipated results.

Recent Advances in Vascular Imaging.

Recent advances in vascular imaging have enabled us to uncover the underlying mechanisms of vascular diseases both ex vivo and in vivo. In the past decade, efforts have been made to establish various methodologies for evaluation of atherosclerotic plaque progression and vascular inflammatory changes in addition to biomarkers and clinical manifestations. Several recent publications in Arteriosclerosis, Thrombosis, and Vascular Biology highlighted the essential roles of in vivo and ex vivo vascular imaging, including magnetic resonance image, computed tomography, positron emission tomography/scintigraphy, ultrasonography, intravascular ultrasound, and most recently, optical coherence tomography, all of which can be used in bench and clinical studies at relative ease. With new methods proposed in several landmark studies, these clinically available imaging modalities will be used in the near future. Moreover, future development of intravascular imaging modalities, such as optical coherence tomography-intravascular ultrasound, optical coherence tomography-near-infrared autofluorescence, polarized-sensitive optical coherence tomography, and micro-optical coherence tomography, are anticipated for better management of patients with cardiovascular disease. In this review article, we will overview recent advances in vascular imaging and ongoing works for future developments.

Patient-Level, Institutional, and Temporal Variations in Use of Imaging Modalities to Confirm Pulmonary Embolism.

BACKGROUND: The choice of the imaging modality for diagnosis of pulmonary embolism (PE) could be influenced by provider, patient or hospital characteristics, or over time. However, little is known about the choice of the diagnostic modalities in practice. The aim of this study was to evaluate the variations in the use of imaging modalities for patients with acute PE. METHODS: Using the data from Registro Informatizado Enfermedad TromboEmbolica (RIETE), a prospective international registry of patients with venous thromboembolism (March 2001-January 2019), we explored the imaging modalities used in patients with acute PE. The imaging modalities included computed tomography pulmonary angiography, ventilation/perfusion scanning, pulmonary angiography, a combination of these tests, or PE signs and symptoms plus imaging-confirmed proximal deep vein thrombosis but no chest imaging. RESULTS: Among 38 025 patients with confirmed PE (53.1% female, age: 67.3±17 years), computed tomography pulmonary angiography was the dominant modality of diagnosis in all RIETE enrollees (78.2% [99% CI, 77.6-78.7]); including pregnant patients (58.9% [99% CI, 47.7%-69.4%]) and patients with severe renal insufficiency (62.5% [99% CI, 59.9-65.0]). A greater proportion of patients underwent ventilation/perfusion scanning in larger hospitals compared with smaller hospitals (13.1% versus 7.3%, P<0.001). The use of computed tomography pulmonary angiography varied between 13.3% and 98.3% across the countries, and its use increased over time (46.5% in 2002 to 91.7% in 2018, P<0.001). CONCLUSIONS: In a large multinational PE registry, variations were observed in the use of imaging modalities according to patient or institutional factors and over time. However, computed tomography pulmonary angiography was the dominant modality of diagnosis, even in pregnancy and severe renal insufficiency. The safety, costs, and downstream effects of these tests on PE-related and non-PE-related outcomes warrant further investigation.

White Matter Integrity in Tanzanian Children With Sickle Cell Anemia: A Diffusion Tensor Imaging Study.

Background and Purpose- Widespread reductions in white matter integrity are associated with cognitive dysfunction in sickle cell anemia. Silent cerebral infarction (SCI), vasculopathy (VSC), and low hemoglobin concentration (Hb) are implicated; we aimed to determine independent contributions to microstructural white matter injury and whether white matter integrity differs across arterial territories. Methods- Sixty two children with sickle cell anemia aged 6 to 19 years were prospectively studied at Muhimbili National Hospital, Tanzania. SCI± and VSC± were identified on magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA) scans by 2 neuroradiologists. Tract-based spatial statistics tested for voxel-wise differences in diffusion tensor imaging metrics (ie, fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity) between SCI± and VSC± groups, with correlations between diffusion tensor imaging metrics and Hb. In tract-based spatial statistics analyses, potentially mediating factors (ie, age, sex, as well as Hb, SCI, and/or vasculopathy) were covariates. Differences in mean diffusion tensor imaging metrics across regions of interest in arterial territories were explored. Results- Compared with SCI- patients (n=45), SCI+ patients (n=17) exhibited increased radial diffusivity in multiple regions; negative relationships were observed between mean diffusivity, axial diffusivity, and Hb (P<0.005). Compared with VSC- patients (n=49), mild (n=6) or moderate (n=7) VSC+ patients exhibited reduced fractional anisotropy in widespread regions (P<0.05) including the anterior longitudinal fasciculi, corpus callosum, internal capsule, corona radiata, and corticospinal tracts. Overall, the posterior cerebral arterial territory had higher mean mean diffusivity and mean radial diffusivity than the anterior and middle cerebral arterial territories, although no patient had vasculopathy in this area. There was an interaction between territory and vasculopathy. Conclusions- SCI, vasculopathy, and Hb are independent risk factors, and thus treatment targets, for diffuse white matter injury in patients with sickle cell anemia. Exacerbation of hemodynamic stress may play a role.

Current and Emerging Imaging Techniques in Patients with Genetic Aortic Syndromes. / Aktuelle Bildgebungs-Strategien bei genetisch bedingten Erkrankungen der Aorta.

BACKGROUND: Patients with genetic aortic syndromes such as Marfan or Loeys-Dietz syndrome have a decreased life expectancy due to the risk of aortic dissection and rupture. Imaging plays an important role in the acute setting but also in the initial diagnosis and image-based monitoring. In this article, we provide an overview of the most common genetic aortic syndromes and recommended imaging strategies. Furthermore, we highlight modern imaging methods allowing for the quantification of hemodynamic changes in aortic disease. METHOD: This is a narrative review article on genetic aortic syndromes and recommended imaging strategies, where we take into account expert opinions and standard-of-care practices from our own center. RESULTS AND CONCLUSION: Radiological imaging plays a key role in the initial diagnosis and surveillance of patients with genetic aortic syndromes. Radiologists contribute significantly to the multi-disciplinary setting of genetic aortic syndromes with knowledge of special features and recommended imaging methods. Accurate measurement of the aorta is crucial, particularly in terms of diameter-based surgical treatment algorithms. Modern imaging methods like 4D-flow MRI and pulse wave velocity have a potential to further improve individualized risk stratification in patients with genetic aortic syndromes. KEY POINTS: · The risk for cardiovascular complications such as acute aortic syndrome is increased in patients with genetic aortic syndromes.. · Recommended time intervals between image-based monitoring depend on the underlying aortic disease.. · CT-angiography should be used only in the acute setting.. · Non-contrast MR-angiography is adequate for screening and image-based monitoring of patients with genetic aortic syndromes.. CITATION FORMAT: · Weinrich JM, Lenz A, Girdauskas E et al. Current and Emerging Imaging Techniques in Patients with Genetic Aortic Syndromes. Fortschr Röntgenstr 2020; 192: 50 - 58.

Preprocedural Cross-Sectional Imaging Prior to Percutaneous Peripheral Arterial Disease Interventions.

Preprocedural cross-sectional imaging (PCSI) for peripheral artery disease (PAD) may vary due to patient complexity, anatomical disease burden, and physician preference. The objective of this study was to determine the utility of PCSI prior to percutaneous vascular interventions (PVIs) for PAD. Patients receiving first time lower extremity angiograms from 2013 to 2015 at a single institution were evaluated for PCSI performed within 180 days, defined as computed tomography angiography (CTA) or magnetic resonance angiography (MRA) evaluating abdominal to pedal vasculature. The primary outcome was technical success defined as improving the target outflow vessels to <30% stenosis. Of the 346 patients who underwent lower extremity angiograms, 158 (45.7%) patients had PCSI, including 150 patients had CTA and 8 patients had MRA. Of these, 48% were ordered by the referring provider (84% at an outside institution). Preprocedural cross-sectional imaging was performed at a median of 26 days (interquartile range: 9-53) prior to the procedure. The analysis of the institution's 5 vascular surgeons identified PCSI rates ranging from 31% to 70%. On multivariate analysis, chronic kidney disease (odds ratio [OR] = 0.35; 95% confidence interval [CI]: 0.17-0.73) was associated with less PSCI usage, and inpatient/emergency department evaluation (OR = 3.20; 95% CI: 1.58-6.50) and aortoiliac disease (OR = 2.78; 95% CI: 1.46-5.29) were associated with higher usage. After excluding 31 diagnostic procedures, technical success was not statistically significant with PSCI (91.3%) compared to without PCSI (85.6%), P = .11. When analyzing 89 femoral-popliteal occlusions, technical success was higher with PCSI (88%) compared to procedures without (69%) P = .026. Our analysis demonstrates that routine ordering of PCSI may not be warranted when considering technical success of PVI; however, PCSI may be helpful in treatment planning. Further studies are needed to confirm these findings in another practice setting, with more prescriptive use of PCSI to improve procedural success, and thereby improve the value of PCSI.

Emerging techniques in atherosclerosis imaging.

Atherosclerosis is a chronic immunomodulated disease that affects multiple vascular beds and results in a significant worldwide disease burden. Conventional imaging modalities focus on the morphological features of atherosclerotic disease such as the degree of stenosis caused by a lesion. Modern CT, MR and positron emission tomography scanners have seen significant improvements in the rapidity of image acquisition and spatial resolution. This has increased the scope for the clinical application of these modalities. Multimodality imaging can improve cardiovascular risk prediction by informing on the constituency and metabolic processes within the vessel wall. Specific disease processes can be targeted using novel biological tracers and "smart" contrast agents. These approaches have the potential to inform clinicians of the metabolic state of atherosclerotic plaque. This review will provide an overview of current imaging techniques for the imaging of atherosclerosis and how various modalities can provide information that enhances the depiction of basic morphology.

Association between initial NIHSS score and recanalization rate after endovascular thrombectomy.

BACKGROUND: National institutes of Health Stroke Scale (NIHSS) score and the presence of successful recanalization are crucial determinants of clinical outcome in patients with major artery occlusion. However, it is unknown whether successful recanalization rate after endovascular therapy (EVT) depends on NIHSS score. METHODS: From our prospective EVT registry, data on patients with an occlusion at the internal carotid artery or middle cerebral artery were analyzed. Successful recanalization was judged as positive when reperfusion of the thrombolysis in cerebral infarction (TICI) scale ≥2b was observed. Successful recanalization rate was also evaluated based on the NIHSS score subgroups: 0-8, 9-16, 17-24, and >24. Multivariate regression analysis was used to evaluate the impact of NIHSS score on successful recanalization. RESULTS: We studied 183 patients (age 76 [68-83], male 110 [60%], NIHSS score 19 [14-24]). One hundred and forty-six (80%) patients had the successful recanalization. Patients achieved the recanalization had lower NIHSS score as 18 (12-23), contrary those failed it had higher NIHSS score as 24 (20-27) (p < .001). Successful recanalization rate was correlated to the NIHSS score grade; 100% in the NIHSS 0-8 group, 88% in 9-16, 81% in 17-24, and only 60% in >24 (p < .001). Multivariate regression analysis showed NIHSS score was an independent parameter of recanalization (odds ratio 0.905 [95%CI 0.837-0.979], p = .013). CONCLUSION: NIHSS score may serve as a predictor of successful recanalization. Recanalization is relatively easier in mild stroke than in those with severe stroke.

Decrease in Secondary Neck Vessels in Multiple Sclerosis: A 5-year Longitudinal Magnetic Resonance Angiography Study.

BACKGROUND: Studies have previously shown greater arterial and venous extracranial vascular changes in persons with multiple sclerosis (PwMS) when compared to healthy controls (HCs). OBJECTIVES: To determine the change in the number and size of secondary neck vessels in PwMS and HCs over a 5-year follow-up period. METHODS: Both at baseline and follow-up, 83 PwMS and 25 HCs underwent magnetic resonance angiography (MRA) imaging and analysis. The number and cross-sectional area (CSA) of all secondary neck vessels (excluding the common/internal carotid, vertebral artery, and internal jugular vein) measured at levels from C2-T1 were determined by semi-automated edge detection/ contouring software. The longitudinal change in the number and CSA of the secondary neck vessels from the PwMS and HCs were analyzed by non-parametric Wilcoxon repeated measure. Benjamini-Hochberg procedure adjusted for false discovery rate (FDR). RESULTS: For over 5 years, PwMS demonstrated a consistent longitudinal decrease in both the number of secondary neck vessels (Z-change between -3.3 and -5.4, q=0.001) and their CSA (Zchange between -2.9 and -5.2, q=0.004). On the contrary, the HCs did not demonstrate a significant longitudinal change in secondary neck vessels over the follow-up period. Due to the longitudinal decrease, the PwMS showed a lower number of secondary neck vessels when compared to HCs measured at follow-up (p<0.029, except for C4 with trending p=0.071). The PwMS changes were also corroborated within each MS phenotype. CONCLUSION: PwMS demonstrate a significant mid-term decrease in the number and the size of the secondary neck vessels. The clinical relevance of these findings and the effect on intracranial blood flow are currently unknown.

Role of imaging techniques in liver veno-occlusive disease diagnosis: recent advances and literature review.

INTRODUCTION: Veno-occlusive-disease (VOD), known also as sinusoidal-obstruction-syndrome (SOS), is one of the main complications of haematopoietic stem cell transplantation and is related to the treatment with pyrrolizidine alkaloids or other toxic agents (chemotherapy for liver-metastasis). Clinical diagnosis using the recent criteria from the European Society for Blood and Marrow Transplantation, is the reference for VOD/SOS diagnosis. However, increasing evidence suggests the emerging role of several imaging methods that could help the clinician in VOD/SOS assessment. Areas covered: This review evaluates the current literature on the various imaging techniques used in VOD/SOS diagnosis in several clinical scenarios. Literature searches were performed using several keywords on MEDLINE/Ovid/In-Process/Cochrane Library/EMBASE and PubMed up to July 2018. Expert commentary: Hepatic-gradient-measurement (HVPG) and contextual transjugular-liver-biopsy are invasive and should always be considered in unclear cases. The main studies revolve around ultrasound with Doppler evaluation, identifying numerous findings suggestive of VOD/SOS. However, their accuracy and validation are still suboptimal and controversial. CT-Scan and MRI have shown encouraging data in other contexts in which VOD/SOS can develop, but studies on the post-HSCT patient are lacking. Elastography techniques measuring liver stiffness (LSM) represent the most recent and promising approach for an accurate and early diagnosis of VOD/SOS. In our view, a multidisciplinary approach to the VOD/SOS diagnosis should be highly encouraged.

Gating Approaches in Cardiac PET Imaging.

Cardiac PET provides high sensitivity and high negative predictive value in the diagnosis of coronary artery disease and cardiomyopathies. Cardiac, respiratory as well as bulk patient motion have detrimental effects on thoracic PET imaging, in particular on cardiovascular PET imaging where the motion can affect the PET images quantitatively as well as qualitatively. Gating can ameliorate the unfavorable impact of motion additionally enabling evaluation of left ventricular systolic function. In this article, the authors review the recent advances in gating approaches and highlight the advances in data-driven approaches, which hold promise in motion detection without the need for complex hardware setup.

Anatomy of the deep venous system in vein of Galen malformation and its changes after endovascular treatment depicted by magnetic resonance venography.

BACKGROUND AND PURPOSE: It is classically thought that the internal cerebral veins (ICV) do not communicate with the venous pouch of vein of Galen malformations (VGM). We report on the anatomy of the deep venous system in VGM with special emphasis on the drainage of the ICV and possible changes after endovascular treatment. MATERIALS AND METHODS: We retrospectively analyzed DSA and 2D time-of-flight MR venograms of 55 children with VGM. We evaluated all pre- and post-operative images for the presence of the ICVs and determined their route of venous drainage. RESULTS: Of 55 children, pre-operative 2D MRV detected the ICVs in 19 cases (35%) compared with one case (2%) for pre-embolization DSA (2%) (P<0.0001). Of the cases in which the ICVs were seen preoperatively, in 15 cases (78.9%) the ICV drained directly into the VGM while in the other four cases, the ICV used alternative venous drainage routes. On post-operative MRV, the ICVs were seen in 17 cases (31%) on MRV and 10 cases (18.2%) on DSA with drainage into an adult-like vein of Galen in 13 cases (76%), respectively (P=0.08). In four cases normal ICV drainage into the vein of Galen was seen even when the venous sac was closed. In two cases there was a change in ICV drainage from the vein of Galen to the lateral mesencephalic vein. CONCLUSION: The communication of the ICV with the VGM is a common phenomenon. Different changes of venous drainage routes do occur after treatment and are best seen on MRV.

A Meta-Analysis of Risk Factors for the Formation of de novo Intracranial Aneurysms.

BACKGROUND: Understanding the risk factors for the formation of de novo intracranial aneurysms (IAs) is important for patients who have ever suffered a cerebral aneurysm. OBJECTIVE: To estimate the risk factors for the development of a de novo IA to identify which patients need more aggressive surveillance after aneurysm treatment. METHODS: We followed the preferred reporting items for systematic reviews and meta-analyses guidelines and searched the PubMed, CENTRAL, EMBASE, and LILACS databases using the key words cerebral aneurysms, de novo, IAs, risk factors combined using and/or. The search was performed in July 2017.We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using RevMan 5.3 (Cochrane, London, United Kingdom) to evaluate risk factors. Statistical significance was set at P < .05. RESULTS: The analysis included 14 studies involving 6389 patients, of whom 197 patients had de novo IAs. The main risk factors for formation included sex (OR = 1.82, 95% CI [1.30,2.56], P = .0005, female vs male), age <40 yr (OR = 2.96, 95% CI [1.76,4.96], P < .0001), family history (OR = 2.05, 95% CI [1.07,3.93], P = .03), smoking history (OR = 2.73, 95% CI [1.81,4.12], P < .0001), and multiple saccular intracranial aneurysms (sIAs) at first diagnosis (OR = 2.10, 95% CI [1.12,3.91], P = .02), internal carotid artery (ICA) as the initial site (OR = 2.58, 95% CI [1.43,4.68], P = .002). Heterogeneous analysis showed that these I2 were less than 50% and the results were reliable. CONCLUSION: Observational evidence identified multiple clinical and anatomic risk factors for the formation of de novo IAs, including female sex, age <40 yr, family history, smoking history, multiple sIAs at first diagnosis, and IC as the initial site. More aggressive long-term angiographic follow-up with digital subtraction angiography, computed tomography angiography, or magnetic resonance angiography is recommended for these patients.

Noncontrast MR angiography: An update.

Both computed tomography (CT) angiography (CTA) and contrast-enhanced MR angiography (CEMRA) have proven to be useful and accurate cross-sectional imaging modalities over a wide range of vascular territories and vascular disorders. A key advantage of MRA is that, unlike CTA, it can be performed without the administration of a contrast agent. In this review article we consider the motivations for using noncontrast MRA, potential contrast mechanisms, imaging techniques, advantages, and drawbacks with respect to CTA and CEMRA, and the level of evidence for using the various MRA techniques. In addition, we explore new developments that promise to expand the reliability and range of clinical applications for noncontrast MRA, along with functional MRA capabilities not available with CTA or CEMRA. Level of Evidence: 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:355-373.

Predicting Progression of Intracranial Arteriopathies in Childhood Stroke With Vessel Wall Imaging.

BACKGROUND AND PURPOSE: Childhood arterial ischemic stroke is frequently associated with an intracranial arteriopathy that often progresses in the first 3 to 6 months post stroke. We hypothesized that children with enhancing arteriopathies on vessel wall imaging (VWI) would have a higher risk of arteriopathy progression than those without enhancement. METHODS: Our institutional radiographic database was searched for cases of childhood stroke with VWI. Inclusion criteria consisted of age ranging from 1 month through 20 years, diagnosis of arterial ischemic stroke, available VWI, and follow-up magnetic resonance angiogram. Imaging was reviewed to systematically describe VWI findings, categorize arteriopathies, steroid therapy, and identify progressive arteriopathies using CACADE definitions. RESULTS: Sixteen cases of childhood stroke at Children's Hospital Colorado between January 1, 2010 and July 1, 2016 were reviewed. Strong vessel wall enhancement at presentation was associated with progressive arteriopathy in 83% of cases (10/12), when compared with 0% (0/4) without strong enhancement (P=0.008). CONCLUSIONS: Our case series demonstrates the potential benefit of VWI in children with stroke because it may identify patients who will have progressive arterial disease.

Regional variation in patient selection and treatment for carotid artery disease in the Vascular Quality Initiative.

OBJECTIVE: Previous studies involving large administrative data sets have revealed regional variation in the demographics of patients selected for carotid endarterectomy (CEA) and carotid artery stenting (CAS) but lacked clinical granularity. This study aimed to evaluate regional variation in patient selection and operative technique for carotid artery revascularization using a detailed clinical registry. METHODS: All patients who underwent CEA or CAS from 2009 to 2015 were identified in the Vascular Quality Initiative (VQI). Deidentified regional groups were used to evaluate variation in patient selection, operative technique, and perioperative management. χ2 analysis was used to identify significant variation across regions. RESULTS: A total of 57,555 carotid artery revascularization procedures were identified. Of these, 49,179 patients underwent CEA (asymptomatic: median, 56%; range, 46%-69%; P < .01) and 8376 patients underwent CAS (asymptomatic: median, 36%; range, 29%-51%; P < .01). There was significant regional variation in the proportion of asymptomatic patients being treated for carotid stenosis <70% in CEA (3%-9%; P < .01) vs CAS (3%-22%; P < .01). There was also significant variation in the rates of intervention for asymptomatic patients older than 80 years (CEA, 12%-27% [P < .01]; CAS, 8%-26% [P < .01]). Preoperative computed tomography angiography or magnetic resonance angiography in the CAS cohort also varied widely (31%-83%; P < .01), as did preoperative medical management with combined aspirin and statin (CEA, 53%-77% [P < .01]; CAS, 62%-80% [P < .01]). In the CEA group, the use of shunt (36%-83%; P < .01), protamine (32%-89%; P < .01), and patch (87%-99%; P < .01) varied widely. Similarly, there was regional variation in frequency of CAS done without a protection device (1%-8%; P < .01). CONCLUSIONS: Despite clinical benchmarks aimed at guiding management of carotid disease, wide variation in clinical practice exists, including the proportion of asymptomatic patients being treated by CAS and preoperative medical management. Additional intraoperative variables, including the use of a patch and protamine during CEA and use of a protection device during CAS, displayed similar variation in spite of clear guidelines. Quality improvement projects could be directed toward improved adherence to benchmarks in these areas.