Evaluation of the utility of early routine computed tomography angiography in subarachnoid hemorrhage patient outcomes.

OBJECTIVES: The role of an early CTA approach in neurologically stable patients with nontraumatic SAH has not been assessed. This study explored the use of CTA in clinically stable SAH patients to pre-emptively identify cerebral vasospasm, to evaluate whether this approach is associated with improved clinical outcomes. METHODS: We conducted a retrospective chart review of SAH patients presenting between July 2007 and December 2016 in a single academic center. Patients were divided into two groups: (1) Early CTA (stable patients who underwent a CTA between days 5-8 post-SAH), and (2) Standard Protocol. The co-primary outcomes were a composite of the mRS at discharge and last clinical follow-up (good = 0-2; poor = 3-6). A multivariable binary logistic regression was conducted to compare both groups against outcomes, controlling for potential confounders. RESULTS: A total of 415 patients were included, 103 (24.8%) with early CTA, and 312 (75.2%) undergoing the standard protocol; the mean age was 57 years and 248 (59.8%) patients were female. Patients in the early CTA group had a higher modified Fisher grade (3-4) (87.4% vs 63.1%; p < 0.02). The multivariable analysis showed that early CTA was independently associated with lower poor outcomes at discharge (OR = 0.21, 95% CI 0.07-0.61, p = 0.004). Plus, vasospasm detection was associated with an increased risk of poor outcomes (OR = 4.77, 95% CI 1.41 - 16.10, p = 0.01). Early CTA was not associated with outcomes at clinical follow-up. CONCLUSION: The early CTA surveillance approach was associated with better functional outcomes at discharge when compared to the current imaging standard practice.

Hematoma Expansion in Intracerebral Hemorrhage With Unclear Onset.

OBJECTIVE: To investigate the prevalence, predictors, and prognostic effect of hematoma expansion (HE) in patients with intracerebral hemorrhage (ICH) with unclear symptom onset (USO). METHODS: We performed a retrospective analysis of patients with primary spontaneous ICH admitted at 5 academic medical centers in the United States and Italy. HE (volume increase >6 mL or >33% from baseline to follow-up noncontrast CT [NCCT]) and mortality at 30 days were the outcomes of interest. Baseline NCCT was also analyzed for presence of hypodensities (any hypodense region within the hematoma margins). Predictors of HE and mortality were explored with multivariable logistic regression. RESULTS: We enrolled 2,165 participants, 1,022 in the development cohort and 1,143 in the replication cohort, of whom 352 (34.4%) and 407 (35.6%) had ICH with USO, respectively. When compared with participants having a clear symptom onset, patients with USO had a similar frequency of HE (25.0% vs 21.9%, p = 0.269 and 29.9% vs 31.5%, p = 0.423). Among patients with USO, HE was independently associated with mortality after adjustment for confounders (odds ratio [OR] 2.64, 95% confidence interval [CI] 1.43-4.89, p = 0.002). This finding was similar in the replication cohort (OR 3.46, 95% CI 1.86-6.44, p < 0.001). The presence of NCCT hypodensities in patients with USO was an independent predictor of HE in the development (OR 2.59, 95% CI 1.27-5.28, p = 0.009) and replication (OR 2.43, 95% CI 1.42-4.17, p = 0.001) population. CONCLUSION: HE is common in patients with USO and independently associated with worse outcome. These findings suggest that patients with USO may be enrolled in clinical trials of medical treatments targeting HE.

Multinational Survey of Current Practice from Imaging to Treatment of Atherosclerotic Carotid Stenosis.

BACKGROUND: In the last 20-30 years, there have been many advances in imaging and therapeutic strategies for symptomatic and asymptomatic individuals with carotid artery stenosis. Our aim was to examine contemporary multinational practice standards. METHODS: Departmental Review Board approval for this study was obtained, and 3 authors prepared the 44 multiple choice survey questions. Endorsement was obtained by the European Society of Neuroradiology, American Society of Functional Neuroradiology, and African Academy of Neurology. A link to the online questionnaire was sent to their respective members and members of the Faculty Advocating Collaborative and Thoughtful Carotid Artery Treatments (FACTCATS). The questionnaire was open from May 16 to July 16, 2019. RESULTS: The responses from 223 respondents from 46 countries were included in the analyses including 65.9% from academic university hospitals. Neuroradiologists/radiologists comprised 68.2% of respondents, followed by neurologists (15%) and vascular surgeons (12.9%). In symptomatic patients, half (50.4%) the respondents answered that the first exam they used to evaluate carotid bifurcation was ultrasound, followed by computed tomography angiography (CTA, 41.6%) and then magnetic resonance imaging (MRI 8%). In asymptomatic patients, the first exam used to evaluate carotid bifurcation was ultrasound in 88.8% of respondents, CTA in 7%, and MRA in 4.2%. The percent stenosis upon which carotid endarterectomy or stenting was recommended was reduced in the presence of imaging evidence of "vulnerable plaque features" by 66.7% respondents for symptomatic patients and 34.2% for asymptomatic patients with a smaller subset of respondents even offering procedural intervention to patients with <50% symptomatic or asymptomatic stenosis. CONCLUSIONS: We found heterogeneity in current practices of carotid stenosis imaging and management in this worldwide survey with many respondents including vulnerable plaque imaging into their decision analysis despite the lack of proven benefit from clinical trials. This study highlights the need for new clinical trials using vulnerable plaque imaging to select high-risk patients despite maximal medical therapy who may benefit from procedural intervention.

Association of masseter area and radiodensity with three-month survival after proximal anterior circulation occlusion.

BACKGROUND: Masseter area (MA), a surrogate for sarcopenia, appears to be useful when estimating postoperative survival, but there is lack of consensus regarding the potential predictive value of sarcopenia in acute ischemic stroke (AIS) patients. We hypothesized that MA and density (MD) evaluated from pre-interventional CT angiography scans predict postinterventional survival in patients undergoing mechanical thrombectomy (MT). MATERIALS AND METHODS: 312 patients treated with MT for acute occlusions of the internal carotid artery (ICA) or the M1 segment of the middle cerebral artery (M1-MCA) between 2013 and 2018. Median follow-up was 27.4 months (range 0-70.4). Binary logistic (alive at 3 months, OR <1) and Cox regression analyses were used to study the effect of MA and MD averages (MAavg and MDavg) on survival. RESULTS: In Kaplan-Meier analysis, there was a significant inverse relationship with both MDavg and MAavg and mortality (MDavg P<0.001, MAavg P=0.002). Long-term mortality was 19.6% (n=61) and 3-month mortality 12.2% (n=38). In multivariable logistic regression analysis at 3 months, per 1-SD increase MDavg (OR 0.61, 95% CI 0.41 to 0.92, P=0.018:) and MAavg (OR 0.57, 95% CI 0.35 to 0.91, P=0.019) were the independent predictors associated with lower mortality. In Cox regression analysis, MDavg and MAavg were not associated with long-term survival. CONCLUSIONS: In acute ischemic stroke patients, MDavg and MAavg are independent predictors of 3-month survival after MT of the ICA or M1-MCA. A 1-SD increase in MDavg and MAavg was associated with a 39%-43% decrease in the probability of death during the first 3 months after MT.

Temporal changes in FFRCT-Guided Management of Coronary Artery Disease - Lessons from the ADVANCE Registry.

BACKGROUND: The ADVANCE registry is a large prospective study of outcomes and resource utilization in patients undergoing coronary computed tomography angiography (CCTA) and CT-based fractional flow reserve (FFRCT). As experience with new technologies and practices develops over time, we investigated temporal changes in the use of FFRCT within the ADVANCE registry. METHODS: 5083 patients with coronary artery disease (CAD) on CCTA were prospectively enrolled in the ADVANCE registry and were divided into 3 equally sized cohorts based on the temporal order of enrollment per site. Demographics, CCTA and FFRCT findings, and clinical outcomes through 1-year follow-up, were recorded and compared between tertiles. RESULTS: The number of patients with a ≥70% stenosis on CCTA was similar over time (33.6%, 30.9%, and 33.8% for cohort 1-3). The rate of positive FFRCT ≤0.80 was higher for cohorts 2 (67.3%) and 3 (74.6%) than for cohort 1 (57.1%, p < 0.001). Invasive FFR rates decreased from 25.8% to 22.4% between cohort 1 and 3 (p = 0.023). Moreover, patients with a FFRCT ≤0.80 were less frequently referred for invasive coronary angiography (ICA) (from 62.9% to 52.9%, p < 0.001), and underwent fewer revascularizations between cohort 1 and 3 (from 41.9% to 32.0%, p < 0.001). The prevalence of major events was low (1.2%) and similar between cohorts. CONCLUSIONS: Growing experience with FFRCT improved the likelihood of identifying hemodynamically significant CAD and safely reduced the need for ICA and revascularization in patients with anatomically significant disease even in the instance of an abnormal FFRCT.

Correlation between CT angiography and digital subtraction angiography in acute ischemic strokes.

OBJECTIVE: CT angiography (CTA) is not necessarily performed for all acute ischemic strokes due to variations in national guidelines across different regions. It follows that in the absence of CTA, missed identification of large vessel occlusion (LVO) potentially leads to opportunity lost for endovascular thrombectomy. Although the accuracy of CTA is well validated in chronic arterial stenosis, it has not been adequately investigated in acute ischemic stroke. We aimed to investigate the accuracy of CTA compared with digital subtraction angiography (DSA) in detecting LVO in acute ischemic stroke. METHODS: This was a retrospective study of acute ischemic strokes with large vessel occlusion which underwent endovascular thrombectomy. We included patients who had a CTA prior to DSA and did not receive intravenous thrombolysis. Images were reviewed by 2 blinded assessors. Positive predictive value (PPV), and negative predictive value (NPV) of CTA were calculated against DSA. RESULTS: Seventy-seven patients were included. The median age was 67 (IQR 57-78) and 46 (59.7 %) were male. Median NIHSS was 18 (IQR 12-22). There were 284 arterial segments categorized into 215 anterior arterial segments in 54 patients and 69 posterior arterial segments in 23 patients. The median time between CTA and DSA was 126 min (IQR 91-153 min). CTA showed PPV of 91.1 % and NPV of 95.1 % compared with DSA. CONCLUSIONS: We showed that CTA was reasonably accurate in identifying large vessel occlusion in acute ischemic stroke. We propose that current regional guidelines should include CTA for all acute ischemic strokes.

Stroke transfers for thrombectomy in the era of extended time.

BACKGROUND AND PURPOSE: The Dawn and Extend Intra-Arterial (IA) acute stroke intervention trials have proven the benefit of thrombectomy in a select group of patients up to 24 h since their last known well time (LKWT) or time of symptom onset. Following the issuance of new treatment guidelines for large vessel occlusion strokes, we reviewed the paradigm shift effect on transfers for possible thrombectomy in a rural state. HYPOTHESIS: Extended time window for thrombectomy increases the need for better identification of potential transfers for thrombectomy in rural states with few hospitals capable of 24/7 interventional thrombectomy. METHODS: We analyzed all transfers to a comprehensive stroke center (CSC) from January to December 2018 which were specifically transferred for possible further intervention. This time period was selected in accordance with the change in American Heart Association (AHA) guidelines for extended time windows in mechanical thrombectomy (MT) care. RESULTS: A total of 132 patients were transferred for possible thrombectomy and advanced imaging. Thirty-four % patients underwent diagnostic angiogram with 33% patients having successful MT. Of the excluded patients 19% had large core infarcts by the time they arrived at hub hospital, 1.5% had hemorrhagic conversion, 32% had stroke without treatable occlusion not amenable for thrombectomy or cortical strokes on follow-up imaging, and 13.5% did not have stroke or LVO on follow-up imaging. CONCLUSION: Since the AHA's change in time window guidelines for mechanical thrombectomies, there has been an increased effort in identifying good candidates with computerized tomography angiography (CTA). To avoid undue burden on stroke systems of care, CTA identification of these patients at the spoke hospitals is key along with timely transport to appropriate thrombectomy capable sites. Given the rural nature of this state along with limited resources, selection of patients is a practical issue, especially for avoiding futile transfers, which might be true for large areas of the USA.

Utilization Rates of Diagnostic and Therapeutic Vascular Procedures Among Patients Undergoing Lower Extremity Amputations in a Rural Community Hospital: A Clinicopathological Correlation.

BACKGROUND: Significant geographical variations exist in amputation rates and utilization of diagnostic and therapeutic vascular procedures before lower extremity amputations in the United States. The purpose of this study was to evaluate the rates of diagnostic and therapeutic vascular procedures in the year prior to amputation in a contemporary population and correlate with pathological findings of the amputation specimens. METHODS: A retrospective analysis was conducted of non-traumatic amputations from 2011 to 2017 at a rural community hospital. We reviewed the proportion of patients undergoing diagnostic (ankle brachial index with duplex ultrasound, computerized tomography angiogram and invasive angiogram) and therapeutic (endovascular and surgical revascularization) vascular procedures in the year prior to amputation. Prevalence of tissue viability and osteomyelitis were evaluated in all amputated specimens and atherosclerotic vascular disease (ASVD) was evaluated in major amputations. We also analyzed primary amputation rates among different subgroups. RESULTS: 698 patients were included with 248 (36%) major amputations and 450 (64%) minor amputations. Any diagnostic procedure was performed in 59% of the major amputations and 49% of the minor amputations (P = 0.01). Any therapeutic revascularization procedure was performed in 34% of the major amputations and 28% of the minor amputations (P = 0.08). The pathology of major amputation specimens revealed severe ASVD in 57% and mild-moderate ASVD in 27% of specimens. Tissue viability was significantly higher in major amputations (90% vs 30%, P = 0.04) and osteomyelitis was significantly higher in minor amputations (50% vs 14%, P = 0.03). Primary amputations were performed in 66% of major amputations, 72% of minor amputations, 81% with mild to moderate ASVD and 54% with severe ASVD. CONCLUSION: Diagnostic and therapeutic vascular procedures appear under-utilized for patients undergoing lower extremity amputations at a rural community hospital. ASVD rates and tissue viability imply that revascularization could be of significant benefit to avoid major amputation.

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.

May endovascular thrombectomy without CT perfusion improve clinical outcome?

BACKGROUND: DAWN and DEFUSE-3 trials demonstrated the benefit of endovascular thrombectomy in late-presenting acute ischemic strokes due to anterior circulation large vessel occlusion. The aim of our study is to evaluate results of endovascular thrombectomy in large intracranial vessel occlusion without perfusion CT patient selection. METHODS: we reviewed our prospectively collected endovascular databases for patients with an acute stroke from March 2016 to October 2018, treated after 6 h from stroke onset, without perfusion CT selection. Baseline characteristics, procedural data, and outcomes were evaluated. A good outcome was defined as a 90-day modified Rankin Scale score of 0-2. The association between clinical and procedural parameters and functional outcome was assessed. RESULTS: out of 212 patients 55 were treated after 6 h from stroke onset, 49 of which for an anterior circulation occlusion. 18/49 were functional independent at 90 days (mRS 0-2), Successful recanalization (mTICI 2b to 3) was achieved in 38/49 patients (77 %). Multivariate logistic regression indicated that a low baseline NIHSS was associated with favorable outcome (OR 0.66, 95 % CI 0.52-0.83, p-value 0.001). CONCLUSIONS: in our retrospective analysis, baseline NIHSS is the only parameter that can predict good outcome (90-days mRS 0-2). We confirm data from recent papers assessing that perfusion CT can provide a better patients' selection compared to mCTA for large vessels occlusion treated beyond six hours from symptom onset.

Comparative Trends in Percutaneous Coronary Intervention in Japan and the United States, 2013 to 2017.

BACKGROUND: Adoption of the results of large-scale randomized controlled trials in percutaneous coronary intervention (PCI) may differ internationally, yet few studies have described the potential variations in PCI practice patterns. OBJECTIVES: Using representative national registries, we compared temporal trends in procedural volume, patient characteristics, pre-procedural testing, procedural characteristics, and quality metrics in the United States and Japan. METHODS: The National Cardiovascular Data Registry CathPCI was used to describe care in the United States, and the J-PCI was used to assess practice patterns in Japan (numbers of participating hospitals: 1,752 in the United States and 1,108 in Japan). Both registries were summarized between 2013 and 2017. RESULTS: PCI volume increased by 15.8% in the United States from 550,872 in 2013 to 637,650 in 2017, primarily because of an increase in nonelective PCIs (p for trend <0.001). In Japan, the volume of PCIs increased by 36%, from 181,750 in 2013 to 247,274 in 2017, primarily because of an increase in elective PCIs (p for trend <0.001). The proportion of PCI cases for elective conditions was >2-fold greater in Japan (72.7%) than in the United States (33.8%; p < 0.001). Overall, the ratio of nonelective PCI (vs. elective PCI; 27.3% vs. 66.2%; p < 0.001) and the performance of noninvasive stress testing in patients with stable disease (15.2% vs. 55.3%; p < 0.001) was lower in Japan than in the United States. Computed tomography angiography was more commonly used in Japan (22.3% vs. 2.0%; p < 0.001). CONCLUSIONS: Elective PCI is more than twice as common in Japan as in the United States in contemporary practice. Computed tomography angiography is much more frequently used pre-procedurally in Japan than in the United States.

Coronary Computed Tomography Angiography From Clinical Uses to Emerging Technologies: JACC State-of-the-Art Review.

Evaluation of coronary artery disease (CAD) using coronary computed tomography angiography (CCTA) has seen a paradigm shift in the last decade. Evidence increasingly supports the clinical utility of CCTA across various stages of CAD, from the detection of early subclinical disease to the assessment of acute chest pain. Additionally, CCTA can be used to noninvasively quantify plaque burden and identify high-risk plaque, aiding in diagnosis, prognosis, and treatment. This is especially important in the evaluation of CAD in immune-driven conditions with increased cardiovascular disease prevalence. Emerging applications of CCTA based on hemodynamic indices and plaque characterization may provide personalized risk assessment, affect disease detection, and further guide therapy. This review provides an update on the evidence, clinical applications, and emerging technologies surrounding CCTA as highlighted at the 2019 National Heart, Lung and Blood Institute CCTA Summit.

Multiphasic Computed Tomography Angiography Findings for Identifying Pseudo-Occlusion of the Internal Carotid Artery.

BACKGROUND AND PURPOSE: Differentiation between pseudo-occlusion and true occlusion of internal carotid artery (ICA) is important in treatment planning for acute ischemic stroke patients. We compared the findings of multiphasic computed tomography angiography between cervical ICA pseudo-occlusion and true occlusion at the cervical ICA in patients with anterior circulation acute ischemic stroke to determine their diagnostic value. METHODS: Thirty patients with nonvisualization of the proximal ICA were included. Diagnosis of pseudo- or true occlusion of the ICA was made based on digital subtraction angiography. Diagnostic performances of multiphasic computed tomography angiography findings-(1) a flame-shaped stump and (2) delayed contrast filling at the cervical ICA- were evaluated and compared. The Fisher exact test, χ2 test, or Wilcoxon rank-sum test and McNemar test were used in the data analysis. RESULTS: Twelve patients had true proximal ICA occlusion and 18 had pseudo-occlusion. Delayed contrast filling at the cervical ICA on multiphasic computed tomography angiography was found in all patients with pseudo-occlusion of the ICA, while 1 case of true occlusion showed delayed contrast filling (P<0.001). The presence of a flame-shaped stump was not significantly different between the pseudo- and true occlusion groups. The sensitivity of delayed contrast filling (0.94 [95% CI, 0.73-1]) was significantly higher than that of flame-shaped stump (0.75 [95% CI, 0.36-0.83]). CONCLUSIONS: We demonstrated that the delayed filling sign on multiphasic computed tomography angiography could be a useful and readily available finding for differentiating proximal ICA pseudo-occlusion from true occlusion.

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.

Calculation of Prognostic Scores, Using Delayed Imaging, Outperforms Baseline Assessments in Acute Intracerebral Hemorrhage.

Background and Purpose- Patients with intracerebral hemorrhage (ICH) are often subject to rapid deterioration due to hematoma expansion. Current prognostic scores are largely based on the assessment of baseline radiographic characteristics and do not account for subsequent changes. We propose that calculation of prognostic scores using delayed imaging will have better predictive values for long-term mortality compared with baseline assessments. Methods- We analyzed prospectively collected data from the multicenter PREDICT study (Prediction of Hematoma Growth and Outcome in Patients With Intracerebral Hemorrhage Using the CT-Angiography Spot Sign). We calculated the ICH Score, Functional Outcome in Patients With Primary Intracerebral Hemorrhage (FUNC) Score, and modified ICH Score using imaging data at initial presentation and at 24 hours. The primary outcome was mortality at 90 days. We generated receiver operating characteristic curves for all 3 scores, both at baseline and at 24 hours, and assessed predictive accuracy for 90-day mortality with their respective area under the curve. Competing curves were assessed with nonparametric methods. Results- The analysis included 280 patients, with a 90-day mortality rate of 25.4%. All 3 prognostic scores calculated using 24-hour imaging were more predictive of mortality as compared with baseline: the area under the curve was 0.82 at 24 hours (95% CI, 0.76-0.87) compared with 0.78 at baseline (95% CI, 0.72-0.84) for ICH Score, 0.84 at 24 hours (95% CI, 0.79-0.89) compared with 0.76 at baseline (95% CI, 0.70-0.83) for FUNC, and 0.82 at 24 hours (95% CI, 0.76-0.88) compared with 0.74 at baseline (95% CI, 0.67-0.81) for modified ICH Score. Conclusions- Calculation of the ICH Score, FUNC Score, and modified ICH Score using 24-hour imaging demonstrated better prognostic value in predicting 90-day mortality compared with those calculated at presentation.

Over-Testing for Suspected Pulmonary Embolism in American Emergency Departments: The Continuing Epidemic.

BACKGROUND: No recent data have investigated rates of diagnostic testing for pulmonary embolism (PE) in US emergency departments (EDs), and no data have examined computed tomographic pulmonary angiography (CTPA) rates in subgroups at high risk for adverse imaging outcomes, including young women and children. We hypothesized that over-testing for PE remains a problem. METHODS AND RESULTS: We used electronic health record and billing data for 16 EDs in Indiana and 11 hospitals in the Dallas-Fort Worth area from 2016 to 2019 to locate ED patients who had any of the following: D-dimer, CTPA, scintillation ventilation perfusion lung scanning or formal pulmonary angiography. The primary outcomes were ED encounter volume-adjusted CTPA rate, PE yield rate with subgroup reporting for children (<18 years) and women under 45 years. We also examined the most frequent diagnoses. From a total visit volume of 1 828 010 patient encounters, 97 125 (5.3% of the total volume) had a diagnostic test for PE, including 25 870 patients who had CTPA order without D-dimer (59% of all tests for PE). The yield rate for PE from CTPA scans was 1.3% (1.1%-1.5%) in Indiana and 4.8% (4.2%-5.1%) in Dallas-Fort Worth (pooled rate 3.1%). Linear regression showed that increased D-dimer ordering correlated with increased PE yield rate (Pearson's R2=0.43; P<0.001). From the pooled sample, 59% of CTPAs done were in women, with 21% of all CTPAs performed on women under 45 years of age, and 1.4% (1.3%-1.5%) on children. The most frequent diagnoses were symptom-based descriptions of chest pain (34%) and shortness of breath (6.5%) and the condition-based diagnosis of pneumonia (4.1%). CONCLUSIONS: Over-testing for PE in American EDs remains a major public health problem. Centers with higher D-dimer ordering had higher yield of PE on CTPA. These data suggest the potential for implementation of D-dimer based protocols to reduce low-yield CTPA ordering.

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.

Clot permeability and histopathology: is a clot's perviousness on CT imaging correlated with its histologic composition?

BACKGROUND: Clot perviousness in large vessel occlusion has been shown to be associated with improved recanalization outcomes with mechanical thrombectomy and intravenous thrombolysis. OBJECTIVE: To evaluate the association between clot perviousness based on thrombus attenuation increase (TAI) on CT, and histologic composition of clots in acute ischemic stroke (AIS). METHODS: A retrospective review was completed of patients with AIS secondary to large vessel occlusion, non-contrast CT (NCCT) and CT angiography (CTA) images, and histologic analysis of the retrieved clot. TAI was measured by subtracting clot attenuation on NCCT from the attenuation on CTA. Up to 3 regions of interest (ROIs) were evaluated on each clot; the average attenuation was used for analysis if multiple ROIs were assessed. Pervious clots were defined as TAI ≥10 Hounsfield units (HUs); impervious clots had TAI <10 HU. Histopathologic analyses of clots were assessed for relative compositions of red blood cells (RBCs), white blood cells (WBCs), fibrin, and platelets/other. RESULTS: 57 patients were included. Pervious clots were more likely to be RBC rich (p=0.04); impervious clots were more likely to be fibrin and WBC rich (p=0.01 for both). Pervious clots also had greater RBC density than impervious clots (49.8% and 33.0%, respectively; p=0.006); fibrin density of pervious clots was lower than that of impervious clots (17.8% and 23.2%, respectively; p=0.02). CONCLUSION: Clot perviousness, assessed on NCCT and CTA imaging, is associated with higher RBC density and lower fibrin density, offering a possible explanation for the higher rates of successful thrombectomy and favorable clinical outcome seen in such patients.

Is management of complex abdominal aortic aneurysms consistent? A questionnaire-based survey.

BACKGROUND: Complex abdominal aortic aneurysm (AAA) is a relatively common presentation to the vascular specialist. Despite this there is little consensus on how to manage the often comorbid group of patients. Recent advances in endovascular technology have led to the availability of multiple devices, many of which could be used to treat the same aneurysm. The aim of this study was to quantify this potential variability across vascular specialists from multiple countries. METHODS: An online survey was emailed to members of the Vascular Society for Great Britain and Ireland (VSGBI), the Canadian Society for Vascular Surgery (CSVS) and the Australian and New Zealand Society for Vascular Surgery (ANZSVS). The survey presented a vignette of a 63-year-old woman with significant respiratory comorbidity and a 54 mm juxtarenal AAA (7 mm neck). There were no other adverse morphological features for endovascular repair. The survey included images and questions related to management of the aneurysm. RESULTS: The survey received 238 responses; 61 from ANZSVS, 65 from CSVS and 112 from VSGBI. VSGBI specialists were significantly more likely to continue surveillance than both ANZSVS (odds ratio [OR] 3.41, 95% confidence interval [CI] 1.61-7.65; P<0.001) and CSVS counterparts (OR 2.61, 95% CI: 1.29-5.47; P<0.01). ANZSVS specialists were significantly more likely to perform an endovascular repair than those from CSVS (OR 3.28, 95% CI: 1.50-7.40; P<0.01) and VSGBI (OR 3.65, 95% CI: 1.81-7.59; P<0.001). CSVS specialists were significantly more likely to manage the aneurysm with open surgery than colleagues from the VSGBI (OR 6.57, 95% CI: 2.58-18.46; P<0.001) and ANZSVS (OR 7.18, 95% CI: 2.22-30.79; P<0.001). CONCLUSIONS: Significant variation in the management of a juxtarenal AAA between countries was observed. The same patient would be more likely to have an endovascular repair in Australia and New Zealand, open surgery in Canada and continuing surveillance in the UK and Ireland. This variation reflects the lack of long-term evidence and international consensus on the optimal management of complex AAA.