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Background and Purpose: Ischemic strokes due to isolated posterior cerebral artery (PCA) occlusions represent 5% of all strokes but have significant impacts on patients' quality of life, primarily due to visual deficits and thalamic involvement. Current guidelines for acute PCA occlusion management are sparse, and the prognostic value of perfusion imaging parameters remains underexplored. Methods: We conducted a retrospective analysis of 32 patients with isolated PCA occlusions treated at Johns Hopkins Medical Institutions between January 2017 and March 2023. Patients underwent pretreatment perfusion imaging, with perfusion parameters analyzed using RAPID software. The primary outcome was short‐term clinical outcome as measured by the National Institutes of Health Stroke Scale (NIHSS) at discharge. Results: The median age of the cohort was 70 years, with 34% female and 66% male. Significant correlations were found between NIHSS at discharge and various perfusion parameters, including time‐to‐maximum (Tmax) >6 seconds (ρ =.55, p =.004), Tmax >8 seconds (ρ =.59, p =.002), Tmax >10 seconds (ρ =.6, p =.001), mismatch volume (ρ =.51, p =.008), and cerebral blood volume (CBV) < 34% (ρ =.59, p =.002). Conclusions: Tmax and CBV volumes significantly correlated with discharge NIHSS with marginal superiority of Tmax >10 seconds and CBV <42% volumes. These findings suggest that CT and MR perfusion imaging can play a crucial role in the acute management of PCA strokes, though larger, standardized studies are needed to validate these results and refine imaging thresholds specific to posterior circulation infarcts. [ABSTRACT FROM AUTHOR]

Simple Summary: The spine is the most common site of osseous metastatic involvement. Advances in diagnosing and treating spinal metastasis have improved patient survival and quality of life. There is now a strong focus on customized imaging to enhance treatment planning for tumor ablation and reduce treatment-related complications. This review discusses imaging protocols and findings in the pre- and post-SBRT setting and the imaging features differentiating expected post-SBRT treatment changes from LF. Spine metastases (SMs) are common, arising in 70% of the cases of the most prevalent malignancies in males (prostate cancer) and females (breast cancer). Stereotactic body radiotherapy, or SBRT, has been incorporated into clinical treatment algorithms over the past decade. SBRT has shown promising rates of local control for oligometastatic spinal lesions with low radiation dose to adjacent critical tissues, particularly the spinal cord. Imaging is critically important in SBRT planning, guidance, and response monitoring. This paper reviews the roles of imaging in spine SBRT, including conventional and advanced imaging approaches for SM detection, treatment planning, and post-SBRT follow-up. [ABSTRACT FROM AUTHOR]

Purpose: Thrombolysis in Cerebral Infarction (TICI) 3 represents the optimal angiographic outcome following mechanical thrombectomy (MT) for acute ischemic stroke (AIS). Although it is known to yield better outcomes than TICI 2b, the influence of preprocedural cerebral hemodynamics on the clinical advantage of TICI 3 over TICI 2b remains unexplored. Methods: This single-center retrospective analysis involved patients with anterior circulation AIS who underwent successful recanalization during MT at the Comprehensive Stroke Center, University Hospital, Krakow between January 2019 and July 2023. We assessed the benefit of achieving TICI 2c/3 over TICI 2b on the basis of preprocedural computed perfusion imaging results, primarily focusing on early infarct volume (EIV) and tissue-level collaterals indicated by hypoperfusion intensity ratio (HIR). Good functional outcome (GFO) was defined as a modified Rankin Score < 3 on day 90. Results: The study comprised 612 patients, of whom 467 (76.3%) achieved TICI 2c/3. GFO was more frequent in the TICI 2c/3 group (54.5% vs 69.4%, p < 0.001). There was interaction between the recanalization status and both HIR (Pi = 0.042) and EIV (Pi = 0.012) in predicting GFO, with disproportionately higher impact of HIR and EIV in TICI 2b group. The benefit from TICI 2c/3 over TICI 2b was insignificant among patients with good collaterals, defined by HIR < 0.3 (odds ratio:1.36 [0.58–3.18], p = 0.483). Conclusion: TICI 2c/3 improves patient functional outcomes compared to TICI 2b regardless of EIV. However, such angiographic improvement may be clinically futile in patients with good tissue-level collateralization. Our findings suggest that preprocedural HIR should be considered when optimization of recanalization is considered during MT. [ABSTRACT FROM AUTHOR]

Purpose: Tumour perfusion is a nutrient-agnostic biomarker for cancer metabolic rate. Use of tumour perfusion for cancer growth assessment has been limited by complicated image acquisition, image analysis and limited field-of-view scanners. Long axial field-of-view (LAFOV) PET scan using [15O]H2O, allows quantitative assessment of whole-body tumour perfusion. We created a tool for automated creation of quantitative parametric whole-body tumour perfusion images in metastatic cancer. Methods: Ten metastatic prostate cancer patients underwent dynamic LAFOV [15O]H2O PET (Siemens, Quadra) followed by [18F]PSMA-1007 PET. Perfusion was measured as [15O]H2O K1 (mL/min/mL) with a single-tissue compartment model and an automatically captured cardiac image-derived input function. Parametric perfusion images were automatically calculated using the basis-function method with initial voxel-wise delay estimation and a leading-edge approach. Subsequently, perfusion of volumes-of-interest (VOI) can be directly extracted from the parametric images. We used a [18F]PSMA-1007 SUV 4 fixed threshold for tumour delineation and transferred these VOIs to the perfusion map. Results: For 8 primary tumours, 64 lymph node metastases, and 85 bone metastases, median tumour perfusion were 0.19 (0.15–0.27) mL/min/mL, 0.16 (0.13–0.27) mL/min/mL, and 0.26 (0.21–0.39), respectively. The correlation between calculated perfusion from time-activity-curves and parametric images was excellent (r = 0.99, p < 0.0001). Conclusion: LAFOV PET imaging using [15O]H2O enables truly quantitative parametric images of whole-body tumour perfusion, a potential biomarker for guiding personalized treatment and monitoring treatment response. [ABSTRACT FROM AUTHOR]

Introduction: Pulmonary transit time (PTT) is the time it takes blood to pass from the right ventricle to the left ventricle via the pulmonary circulation, making it a potentially useful marker for heart failure. We assessed the association of PTT with diastolic dysfunction (DD) and mitral valve regurgitation (MVR). Methods: We evaluated routine stress perfusion cardiovascular magnetic resonance (CMR) scans in 83 patients including assessment of PTT with simultaneously available echocardiographic assessment. Relevant DD and MVR were defined as exceeding Grade I (impaired relaxation and mild regurgitation). PTT was determined from CMR rest perfusion scans. Normalized PTT (nPTT), adjusted for heart rate, was calculated using Bazett's formula. Results: Higher PTT and nPTT values were associated with higher grade DD and MVR. The diagnostic accuracy for the prediction of DD as quantified by the area under the ROC curve (AUC) was 0.73 (CI 0.61–0.85; p = 0.001) for PTT and 0.81 (CI 0.71–0.89; p < 0.001) for nPTT. For MVR, the diagnostic performance amounted to an AUC of 0.80 (CI 0.68–0.92; p < 0.001) for PTT and 0.78 (CI 0.65–0.90; p < 0.001) for nPTT. PTT values < 8 s rule out the presence of DD and MVR with a probability of 70% (negative predictive value 78%). Conclusion: CMR‐derived PTT is a readily obtainable hemodynamic parameter. It is elevated in patients with DD and moderate to severe MVR. Low PTT values make the presence of DD and MVR—as assessed by echocardiography—unlikely. [ABSTRACT FROM AUTHOR]

Objective Methods Results Interpretation About 25% of patients with acute ischemic stroke (AIS) present within the intravenous thrombolytic (IVT) therapeutic window of <4.5 h. This study is to elucidate the safety and efficacy of IVT in the extended therapeutic window (ETW) in patients with AIS.Using PRISMA guidelines, a systematic review was conducted using PubMed, Embase, and Scopus. A rigorous risk of bias assessment was conducted using the RoB2 tool. Rates of excellent and good functional outcome (mRS 0–1 and mRS 0–2) at 90 days, symptomatic intracranial hemorrhage (sICH), and mortality at 90 days were pooled using generalized linear mixed model and compared with controls. Meta‐analyses were conducted employing random‐effect models with risk ratio (RR) and 95% confidence intervals (CIs). Subgroup analysis was performed to assess the effect of imaging modalities used for patient selection.Eight randomized controlled trials (n = 2221, 59% male) were included. At 90 days IVT showed higher rates of functional recovery: mRS 0–1: RR 1.21 95% CI 1.1–1.34, p < 0.001, and mRS 0–2: RR 1.11 95% CI 1.03–1.18, p = 0.004. Rate of mortality at 90 day was not different between groups: RR 1.17 95% CI 0.93–1.48, p = 0.17. However, the rate of sICH was higher among IVT group: RR 2.93 95% CI 1.53–5.6, p = 0.001. Subgroup analysis showed higher mRS 0–1 among patients who were selected based on perfusion imaging (p < 0.05).The use of IVT in AIS in ETW is beneficial especially with the use of perfusion imaging for patients' selection. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions While advances in endovascular thrombectomy (EVT) have led to high reperfusion rates, most patients treated with EVT do not avoid disability. Post‐reperfusion hemorrhagic transformation (HT) is a potential target for improving outcomes. This study examined pretreatment blood–brain barrier (BBB) disruption in tissue that would subsequently become part of the final infarct to evaluate its role in post‐EVT HT.This post hoc analysis of the FRAME study, which enrolled patients with anterior large vessel occlusion who received EVT within 6 hours of onset, included patients if they had successful pretreatment MRI perfusion weighted imaging (PWI) and underwent successful EVT. BBB disruption was measured as the percent signal change due to gadolinium leakage on the PWI source images prior to thrombectomy. Mean permeability derangement (MPD) was defined as the average of all voxels in the stroke core that are two standard deviations above normal. The primary outcome was hemorrhagic transformation with parenchymal hematoma (PH).In total, 164 patients were included; mean age was 71 and 48% were female. PH occurred in 57 patients. Median MPD was 13.5% for patients with PH versus 3.6% for patients without (p < 0.0001). Elevated MPD was independently associated with PH with a 20% increased risk of PH for each 5% increase in MPD (OR 1.206; 95% CI 1.037:1.405; p = 0.0147, adjusted for NIHSS and procedure duration).Even in patients who are successfully recanalized in an early time window, pretreatment BBB disruption in regions that go on to infarct is associated with an increased risk of post‐EVT HT. [ABSTRACT FROM AUTHOR]

Background: Technetium-99 m-labelled macroaggregated human serum albumin ([99mTc]Tc-MAA) is commonly used for lung perfusion scintigraphy. The European Pharmacopoeia (Eu.Ph.) specifies thin-layer chromatography (TLC) as the only method to assess its radiochemical purity (RCP). Similarly, TLC is the sole method reported in the literature to evaluate the RCP of Gallium-68-labelled MAA [68 Ga]Ga-MAA, recently introduced for lung perfusion PET/CT imaging. Since [68 Ga]Ga-MAA is prepared from commercial kits originally designed for the preparation of [99mTc]Tc-MAA, it is essential to optimize and validate the preparation methods for [68 Ga]Ga-MAA. Results: We tested a novel, simplified method for the preparation of [68 Ga]Ga-MAA that does not require organic solvents, prewash or final purification steps to remove radioactive impurities. We assessed the final product using radio-TLC, radio-UV-HPLC, and radio SDS-PAGE. Overall, our quality control (QC) method successfully detected [68 Ga]Ga-MAA along with all potential impurities, including free Ga-68, [68 Ga]Ga-HSA, unlabeled HSA, which may occur during labelling process and HEPES residual, a non-toxic but non-human-approved contaminant, used as buffer solution. We then applied our QC system to [68 Ga]Ga-MAA prepared under different conditions (25°–40°–75°–95 °C), thus defining the optimal temperature for labelling. Scanning Electron Microscopy (SEM) analysis of the products obtained through our novel method confirmed that most [68 Ga]Ga-MAA particles preserved the morphological structure and size distribution of unlabeled MAA, with a particle diameter range of 25–50 μm, assuring diagnostic efficacy. Conclusions: We optimized a novel method to prepare [68 Ga]Ga-MAA through a QC system capable of monitoring all impurities of the final products. [ABSTRACT FROM AUTHOR]

BACKGROUND: Coronary microvascular dysfunction has been implicated in the development of hypertensive heart disease and heart failure, with subendocardial ischemia identified as a driver of sustained myocardial injury and fibrosis. We aimed to evaluate the relationships of subendocardial perfusion with cardiac injury, structure, and a composite of major adverse cardiac and cerebrovascular events consisting of death, heart failure hospitalization, myocardial infarction, and stroke. METHODS: Layer-specific blood flow and myocardial flow reserve (MFR; stress/rest myocardial blood flow) were assessed by 13N-ammonia perfusion positron emission tomography in consecutive patients with hypertension without flow-limiting coronary artery disease (summed stress score <3) imaged at Brigham and Women's Hospital (Boston, MA) from 2015 to 2021. In this post hoc observational study, biomarkers, echocardiographic parameters, and longitudinal clinical outcomes were compared by tertiles of subendocardial MFR (MFRsubendo). RESULTS: Among 358 patients, the mean age was 70.6±12.0 years, and 53.4% were male. The median MFRsubendo was 2.57 (interquartile range, 2.08-3.10), and lower MFRsubendo was associated with older age, diabetes, lower renal function, greater coronary calcium burden, and higher systolic blood pressure (P<0.05 for all). In cross-sectional multivariable regression analyses, the lowest tertile of MFRsubendo was associated with myocardial injury and with greater left ventricular wall thickness and volumes compared with the highest tertile. Relative to the highest tertile, low MFRsubendo was independently associated with an increased rate of major adverse cardiac and cerebrovascular events (adjusted hazard ratio, 2.99 [95% CI, 1.39-6.44]; P=0.005) and heart failure hospitalization (adjusted hazard ratio, 2.76 [95% CI, 1.04-7.32; P=0.042) over 1.1 (interquartile range, 0.6-2.8) years median follow-up. CONCLUSIONS: Among patients with hypertension without flow-limiting coronary artery disease, impaired MFRsubendo was associated with cardiovascular risk factors, elevated cardiac biomarkers, cardiac structure, and clinical events. [ABSTRACT FROM AUTHOR]

Introduction: While increased baseline blood pressure (BP) is a prevalent comorbidity in the acute phase of ischemic stroke, the association between baseline BP and the state of hemispheric perfusion in patients with acute small subcortical infarcts (SSIs) has not been studied in detail. The aim of this study was to investigate the relationship between baseline BP and hemispheric cerebral blood flow (CBF) in acute SSIs. Methods: This retrospective study included 101 patients with acute SSIs. Baseline hemispheric CBF was assessed through co-registration of baseline CT perfusion imaging and follow-up diffusion-weighted imaging. The association between baseline BP, CBF, and different cerebral small vessel disease (CSVD) biomarkers was assessed. Results: Baseline systolic BP (SBP) and diastolic BP (DBP) were negatively associated with contralateral hemispheric CBF after multivariate-adjusted linear analysis (SBP: β = −0.001, 95% CI: −0.002 to 0.000, p = 0.030; DBP: β = −0.002, 95% CI: −0.003∼0.001, p = 0.006). Among other CSVD biomarkers, the presence of any cerebral microbleeds showed a significant association with lower CBF in the contralateral hemisphere of the infarct lesion (r = −0.270, p = 0.035). Conclusion: In patients with acute SSIs, increased baseline BP was associated with reduced CBF in the contralateral hemisphere of the infarct lesion, which probably could be interpreted by the exacerbation of the CSVD burden, suggesting a potential mechanistic link between BP autoregulation dysfunction and the aggravation of neurovascular impairment in SSIs. [ABSTRACT FROM AUTHOR]

Purpose • Angiogenesis, the formation of new blood vessels, plays a crucial role in tumor growth and metastasis. Understanding the vascular characteristics of colorectal cancer through preoperative computed tomography (CT) perfusion parameters can provide valuable insights into the tumor’s aggressiveness and potential for spread. Additionally, exploring the correlation between these parameters and serum tumor marker levels may offer a comprehensive perspective on the disease’s biological behavior. Methods • In this retrospective study, we investigated 42 colorectal cancer patients. Based on microvascular density (MVD) measured by immunohistochemistry (IHC), participants were categorized into either a high-density group (n = 24) with MVD ≥ 35/field of view or a low-density group (n = 18) with MVD < 35/field of view. Additionally, a control group comprised 25 patients with pathologically confirmed benign colorectal lesions. This study design allowed us to assess the correlation between MVD and colorectal cancer, differentiating between high and low microvascular density groups, while also comparing results to a control group for comprehensive analysis. Results • Colorectal cancer was associated with significantly higher levels of blood volume (BV; high-density group: 7.65±1.36 mL/100g; low-density group: 6.73±1.29 mL/100g), blood flow (BF; high-density group: 67.33±12.16 ml/(100g·min); low-density group: 52.84±11.43 ml/ (100g·min)), permeability surface (PS; high-density group: 35.19±6.32 ml/(100g·min); low-density group: 22.27±4.85 ml/(100g·min)), serum glycoprotein antigen 19-9 (CA19-9; high-density group: 45.38±5.41 g/ ml); low-density group: 23.43±3.59 g/ml), glycoprotein antigen 125 (CA125; high-density group: 27.56±3.73 g/ml); low-density group: 12.63±2.59 g/ml), and carcinoembryonic antigen (CEA; high-density group: 17.87±3.12 g/ml); low-density group: 8.51±2.87 g/ml) versus benign colorectal lesions, with more significant changes observed in the high-density group versus the low-density group (P ≤ .001). The three groups showed similar mean transit time (MTT). The AUCs under the ROC curves for BV, BF, PS, and TTP were 0.901, 0.898, 0.963, and 0.983, respectively. Pearson correlation analysis showed a positive correlation of patients’ serum CA19-9 with BV, BF, and PS., Serum CA125 and CEA were positively correlated with BF and PS, and the above indicators were negatively correlated with TTP. Conclusions • In conclusion, our study highlights the potential of preoperative CT perfusion imaging as a valuable tool for evaluating angiogenesis in colorectal cancer and its correlation with serum tumor markers. The identified associations open avenues for further research to delve into specific aspects of angiogenesis and tumor markers. Future investigations could focus on elucidating the molecular mechanisms underlying the observed correlations, potentially identifying novel therapeutic targets. Additionally, exploring the dynamic changes in angiogenesis and tumor markers during different stages of colorectal cancer progression may provide a more comprehensive understanding. Moreover, assessing the prognostic value of these imaging and biomarker correlations in larger, diverse patient cohorts could enhance their clinical utility. Our findings lay the groundwork for these future research directions, emphasizing the need for continued exploration to advance our knowledge and improve clinical strategies for colorectal cancer management. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate whether the spatial coefficient of variation of arterial spin labeling (ASL-CoV) acquired in clinical settings can be used to estimate decreased cerebrovascular reactivity (CVR) measured with single-photon emission computed tomography (SPECT) and acetazolamide challenge in patients with atherosclerotic stenosis of intra- or extracranial arteries. Methods: We evaluated the data of 27 atherosclerotic stenosis patients who underwent pseudocontinuous ASL and SPECT. After spatial normalization, regional values were measured using the distributed middle cerebral artery territorial atlas of each patient. We performed comparisons, correlations, and receiver operating characteristic (ROC) curve analyses between ASL-cerebral blood blow (CBF), ASL-CoV, SPECT-CBF and SPECT-CVR. Results: Although the ASL-CBF values were positively correlated with SPECT-CBF values (r = 0.48, 95% confidence interval (CI) = 0.28–0.64), no significant difference in ASL-CBF values was detected between regions with and without decreased CVR. However, regions with decreased CVR had significantly greater ASL-CoV values than regions without decreased CVR. SPECT-CVR was negatively correlated with ASL-CoV (ρ = -0.29, 95% CI = -0.49 - -0.06). The area under the ROC curve of ASL-CoV in predicting decreased CVR (0.66, 95% CI = 0.51–0.81) was greater than that of ASL-CBF (0.51, 95% CI = 0.34–0.68). An ASL-CoV threshold value of 42% achieved a high specificity of 0.93 (sensitivity = 0.42, positive predictive value = 0.77, and negative predictive value = 0.75). Conclusion: ASL-CoV acquired by single postlabeling delay without an acetazolamide challenge may aid in the identification of patients with decreased CVR on SPECT. [ABSTRACT FROM AUTHOR]

Introduction: We aimed to investigate the performance of several neuroimaging markers provided by perfusion imaging of Acute Ischemic Stroke (AIS) patients with large vessel occlusion (LVO) in order to predict clinical outcomes following reperfusion treatments. Methods: We prospectively evaluated consecutive AIS patients with LVO who were treated with reperfusion therapies, during a six-year period. In order to compare patients with good (mRS scores 0–2) and poor (mRS scores 3–6) functional outcomes, data regarding clinical characteristics, the Alberta Stroke Programme Early Computed Tomography Score (ASPECTS) based on unenhanced computed tomography (CT), CT angiography collateral status and perfusion parameters including ischemic core, hypoperfusion volume, mismatch volume between core and penumbra, Tmax > 10 s volume, CBV index and the Hypoperfusion Index Ratio (HIR) were assessed. Results: A total of 84 acute stroke patients with LVO who met all the inclusion criteria were enrolled. In multivariable logistic regression models increasing age (odds ratio [OR]: 0.93; 95%CI: 0.88–0.96, p = 0.001), lower admission National Institute of Health Stroke Scale (NIHSS)-score (OR: 0.88; 95%CI: 0.80–0.95, p = 0.004), pretreatment with intravenous thrombolysis (OR: 3.83; 95%CI: 1.29–12.49, p = 0.019) and HIR (OR:0.36; 95%CI: 0.10–0.95, p = 0.042) were independent predictors of good functional outcome at 3 months. The initial univariable associations between HIR and higher likelihood for symptomatic intracranial hemorrhage (sICH) and parenchymal hematoma type 2 (PH2) were attenuated in multivariable analyses failing to reach statistical significance. Discussion: Our pilot observational study of unselected AIS patients with LVO treated with reperfusion therapies demonstrated that pre-treatment low HIR in perfusion imaging and IVT were associated with better functional outcomes. [ABSTRACT FROM AUTHOR]

We sought to investigate the impact of sex on myocardial perfusion changes following chronic total coronary occlusion (CTO) percutaneous coronary intervention (PCI) as measured by [15O]H 2 O positron-emission tomography (PET) perfusion imaging. CTO PCI has been associated with an increase in myocardial perfusion, yet females are less likely to undergo revascularization. As such, data on the impact of sex on myocardial perfusion following CTO PCI is scarce. A total of 212 patients were prospectively enrolled and underwent CTO PCI combined with [15O]H 2 O PET perfusion imaging prior to and 3 months after PCI. Hyperemic myocardial blood flow (hMBF, mL·min−1·g−1) and coronary flow reserve (CFR) allocated to the CTO territory were quantitatively assessed. This study comprised 34 (16 %) females and 178 (84 %) males. HMBF at baseline did not differ between sexes. Females showed a higher increase in hMBF than males (Δ1.34 ± 0.67 vs. Δ1.06 ± 0.74, p = 0.044), whereas post-PCI hMBF was comparable (2.59 ± 0.85 in females vs. 2.28 ± 0.84 in males, p = 0.052). Female sex was independently associated with a higher increase in hMBF after correction for clinical covariates. CFR increase after revascularization was similar in females and males (Δ1.47 ± 0.99 vs. Δ1.30 ± 1.14, p = 0.711). The present study demonstrates a greater recovery of stress perfusion in females compared to males as measured by serial [15O]H 2 O PET imaging. In addition, a comparable increase in CFR was found in females and males. These results emphasize the benefit of performing CTO PCI in both sexes. What is new? • CTO PCI has been associated with an increase in myocardial perfusion, yet females are less likely to undergo revascularization. • We found a greater recovery of stress perfusion in females compared to males after CTO PCI as measured by serial [15O]H 2 O PET imaging, whereas coronary flow reserve was comparable between sexes. • The present study adds to the limited body of evidence on the impact of sex on myocardial perfusion following CTO PCI. What are the clinical implications? • Our findings suggest that recovery of myocardial perfusion following CTO PCI is achievable in both female and male patients. • These results underscore the need to adhere to current guidelines for optimal CTO management in both sexes. • Future studies with standardized preprocedural imaging are warranted to increase our understanding of the impact of sex on changes in myocardial perfusion following CTO PCI. • CTO PCI is associated with an increase in myocardial perfusion, yet females are less likely to undergo revascularization. • We found a greater recovery of stress perfusion in females after CTO PCI as measured by serial [15O]H 2 O PET imaging. • Our findings suggest that recovery of myocardial perfusion following CTO PCI is achievable in both female and male patients. • These results underscore the need to adhere to current guidelines for optimal CTO management in both sexes. • Studies with preprocedural imaging are warranted to increase our understanding of the impact of sex on MBF after CTO PCI. [ABSTRACT FROM AUTHOR]

Purpose: To compare the diagnostic approach of acute pulmonary embolism (PE) with photon-counting-detector CT (PCD-CT) and energy-integrating-detector CT (EID-CT). Materials and methods: Two cohorts underwent CT angiographic examinations with EID-CT (Group 1; n = 158) and PCD-CT (Group 2; n = 172), (b) with two options in Group 1, dual energy (Group 1a) or single energy (Group 1b) and a single option in Group 2 (spectral imaging with single source). Results: In Group 2, all patients benefited from spectral imaging, only accessible to 105 patients (66.5%) in Group 1, with a mean acquisition time significantly shorter (0.9 ± 0.1 s vs 4.0 ± 0.3 s; p < 0.001) and mean values of CTDIvol and DLP reduced by 46.3% and 47.7%, respectively. Comparing the quality of 70 keV (Group 2) and averaged (Group 1a) images: (a) the mean attenuation within pulmonary arteries did not differ (p = 0.13); (b) the image noise was significantly higher (p < 0.001) in Group 2 with no difference in subjective image noise (p = 0.29); and (c) 89% of examinations were devoid of artifacts in Group 2 vs 28.6% in Group 1a. The percentage of diagnostic examinations was 95.2% (100/105; Group 1a), 100% (53/53; Group 1b), and 95.3% (164/172; Group 2). There were 4.8% (5/105; Group 1a) and 4.7% (8/172; Group 2) of non-diagnostic examinations, mainly due to the suboptimal quality of vascular opacification with the restoration of a diagnostic image quality on low-energy images. Conclusion: Compared to EID-CT, morphology and perfusion imaging were available in all patients scanned with PCD-CT, with the radiation dose reduced by 48%. Clinical relevance statement: PCD-CT enables scanning patients with the advantages of both spectral imaging, including high-quality morphologic imaging and lung perfusion for all patients, and fast scanning—a combination that is not simultaneously accessible with EID-CT while reducing the radiation dose by almost 50%. Key Points: The complementarity between morphology and perfusion imaging is accessible in each PCD-CT examination. High-quality images are obtained with PCD-CT in all categories of patients, including dyspneic patients. PCD-CT enables about 50% radiation dose reduction compared with EID-CT. [ABSTRACT FROM AUTHOR]

Background Purpose Methods Results Conclusions Perfusion magnetic resonance imaging (MRI)s plays a central role in the diagnosis and monitoring of neurovascular or neurooncological disease. However, conventional processing techniques are limited in their ability to capture relevant characteristics of the perfusion dynamics and suffer from a lack of standardization.We propose a physics‐informed deep learning framework which is capable of analyzing dynamic susceptibility contrast perfusion MRI data and recovering the dynamic tissue response with high accuracy.The framework uses physics‐informed neural networks (PINNs) to learn the voxel‐wise TRF, which represents the dynamic response of the local vascular network to the contrast agent bolus. The network output is stabilized by total variation and elastic net regularization. Parameter maps of normalized cerebral blood flow (nCBF) and volume (nCBV) are then calculated from the predicted residue functions. The results are validated using extensive comparisons to values derived by conventional Tikhonov‐regularized singular value decomposition (TiSVD), in silico simulations and an in vivo dataset of perfusion MRI exams of patients with high‐grade gliomas.The simulation results demonstrate that PINN‐derived residue functions show a high concordance with the true functions and that the calculated values of nCBF and nCBV converge towards the true values for higher contrast‐to‐noise ratios. In the in vivo dataset, we find high correlations between conventionally derived and PINN‐predicted perfusion parameters (Pearson's rho for nCBF: 0.84±0.03$0.84 \pm 0.03$ and nCBV: 0.92±0.03$0.92 \pm 0.03$) and very high indices of image similarity (structural similarity index for nCBF: 0.91±0.03$0.91 \pm 0.03$ and for nCBV: 0.98±0.00$0.98 \pm 0.00$).PINNs can be used to analyze perfusion MRI data and stably recover the response functions of the local vasculature with high accuracy. [ABSTRACT FROM AUTHOR]

Objective: To investigate the application value of dual-source CT cerebral perfusion imaging combined with serum ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) and lipoprotein-associated phospholipase A2(Lp-PLA2) in the diagnosis and poor prognosis prediction of patients with acute cerebral infarction (ACI). Methods: 151 ACI patients admitted to Hulunbuir People's Hospital from February 2021 to March 2023 were selected as ACI group and 109 healthy volunteers as control group. According to the National Institutes of Health Stroke Scale (NIHSS), ACI patients were divided into mild group (52 cases), moderate group (53 cases), severe group (46 cases); and according to the Modified Rankin Score Scale (mRS), ACI patients were divided into poor prognosis group (37 cases) and good prognosis group (114 cases). All subjects were underwent dual-source CT cerebral perfusion imaging to obtain relevant parameters of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time to peak (TTP), and serum UCH-L1 and Lp-PLA2 levels were detected. The value of dual-source CT cerebral perfusion imaging parameters combine with serum UCH-L1 and Lp-PLA2 in the diagnosis of ACI and predicted the prognosis of ACI patients were analyzed by receiver operating characteristic (ROC) curve. Results: CBF and CBV in ACI group were lower than those in control group(P<0.05), MTT and TTP in ACI group were longer than those in control group (P < 0.05) serum UCH-L1 and Lp-PLA2 levels in ACI group were higher than those in con- trol group (P < 0.05) CBF and CBV in severe group were lower than those in moderate group and mild group(P<0.05), MTT and TTP in severe group were longer than those in moderate group and mild group(P<0.05), and serum UCH-L1 and Lp-PLA2 levels in severe group were higher than those in moderate group and mild group (P < 0.05) CBF and CBV in moderate group were lower than those in mild group (P < 0.05) MTT and TTP in moderate group were longer than those in mild group(P<0.05), and serum UCH-L1 and Lp-PLA2 levels in moderate group were higher than those in mild group (P < 0.05) . CBF and CBV in poor prognosis group were lower than those in good prognosis group (P < 0.05) MTT and TTP in poor prognosis group were longer than those in good prognosis group (P < 0.05) and serum UCH-L1 and Lp-PLA2 levels in poor prognosis group were higher than those in good prognosis group (P < 0.05) ROC curve analysis showed that: the area under the curve of combine dual-source CT cerebral perfusion imaging parameters and serum UCH-L1 and Lp-PLA2 in the diagnosis of ACI and the prediction of poor prognosis of ACI were 0.898 and 0.892, respectively, which were higher than those of single index diagnosis and prediction. Conclusion: In ACI patients, dual-source CT cerebral perfusion imaging parameters CBF and CBV decrease, MTT and TTP prolonged, serum UCH-L1 and Lp-PLA2 levels increase, which are relate to the aggravation of ACI nerve defect and poor prognosis. The combination of dual-source CT cerebral perfusion imaging parameters and serum UCH-L1 and Lp-pLA2 has high value in the diagnosis and prognosis analysis of ACI. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to validate hyperintense vessel sign (HVS) on FLAIR imaging or posterior cerebral artery (PCA) laterality on MR angiography beyond 4.5 hours after stroke onset. Materials and methods: Data from acute ischemic stroke patients with internal carotid or middle cerebral artery occlusion who underwent CT perfusion imaging at baseline, follow-up MR perfusion imaging and angiography within 30 hours after stroke, without effective recanalization on follow-up imaging, were analysed retrospectively. Patients were separately classified as high or low HVS (>5 or ≤5 slices of HVS), and PCA laterality positive or negative group. We compared core and penumbra volumes at follow-up imaging and neurological outcomes between high or low HVS group, and between PCA laterality positive or negative group. Results: Of 49 patients analyzed, four patients with artifacts were excluded and 45 were classified into high (n = 23) or low (n = 22) HVS group. High group had a smaller core volume (median 32 ml versus 109 ml, p = 0.004), larger penumbra volume at follow-up (68 ml versus 0 ml, p = 0.001), and better outcomes (modified Rankin Scale at three months, 3 versus 5, p = 0.03). For PCA laterality analysis, 1 patient with previously occluded PCA was excluded and 48 patients were classified as positive (n = 22) or negative (n = 26). Positive group had larger core volume (116 ml versus 37 ml), and no significant differences in penumbral volumes or outcomes. Conclusion: Prominent HVS in later time was associated with small core volume, persistent penumbra volume and favorable outcomes. [ABSTRACT FROM AUTHOR]

Introduction: Adult and pediatric ECMO procedures have been increasingly established as conventional life-saving modalities in critical care services across the world. Since 2017, a multidisciplinary team of program advisors for our perfusion education program have aimed to increase cardiovascular perfusion (CVP) student ECMO exposure and improve clinical decision-making. In this QI intervention, the use of 3D computer-based simulation was assessed in establishing a standardized process to improve the diagnosis and treatment of adult ECMO complications among first year CVP students. Methods: The Califia 3D Patient Simulator was incorporated into the curriculum for first year CVP students (n = 26) along with traditional lecture for the adult ECMO complication laboratory session. Pre-class knowledge assessments using de-identified polling software were compared to post-class assessments following the first assigned learning activity. Assessments from students that received simulation before lecture (SIM, n = 15) were compared to students receiving lecture before simulation (LEC, n = 11). User experience questionnaires (UEQ) consisting of 26 questions for six scales of simulation instruction were administered to measure the comprehensive impression of the student experience. Results: Overall median [IQR] pre- and -post knowledge assessment scores were 74% [11] and 84% [11], respectively (p = 0.01). There were no significant differences in pre-class assessment scores between the SIM and LEC groups (74.0% and 74.0%, respectively, p = 0.959). The LEC group achieved higher median post-assessment scores than the SIM group (84% vs 79%, p = 0.032). Among the 26 UEQ survey scales, 23 were positively evaluated (>0.8), and three were a neutral evaluation (−0.8 to 0.8). Cronbach Alpha-Coefficients of >0.78 were measured for attractiveness, perspicuity, efficacy, and stimulation. The coefficient for dependability was 0.37. 25 (96.2%) students indicated that 3D simulation was beneficial to improving ECMO clinical decision-making. Conclusions: In this QI intervention, the implementation of computer-based 3D simulation following lecture was perceived by learners to help improve the diagnosis and treatment of ECMO-related complications. [ABSTRACT FROM AUTHOR]

Introduction: Cardiovascular Magnetic Resonance (CMR) has become an essential non-invasive imaging modality in the diagnosis and management of various cardiac conditions. Its ability to provide detailed assessments of myocardial perfusion and scar tissue without ionizing radiation offers distinct advantages over other imaging techniques. Aim is to evaluate the role of Cardiovascular Magnetic Resonance (CMR) in assessing myocardial perfusion and scar tissue and to investigate the correlation of CMR findings with clinical parameters and outcomes, including angina symptoms, history of myocardial infarction, and revascularization procedures. Materials and Methods: This prospective observational study was conducted with a sample size of 75 patients who had clinical indications for CMR. The study included adult’s aged 18 years and older, excluding those with contraindications to MRI or severe renal impairment. CMR imaging was performed using a 1.5 Tesla MRI scanner, incorporating cine imaging, stress and rest perfusion imaging, late gadolinium enhancement (LGE), and T1 and T2 mapping. Results: The study found that 30% of participants exhibited myocardial perfusion defects, with a mean scar burden of 15% across the study cohort. Participants with angina symptoms, a history of myocardial infarction, or those who underwent revascularization procedures had higher scar burdens and lower left ventricular ejection fractions (LVEF). Significant correlations were observed between CMR findings and clinical outcomes, with participants who had a history of myocardial infarction showing the highest scar burden (mean 30%) and lowest LVEF (mean 45%). Conclusion: CMR is a valuable tool for evaluating myocardial perfusion and scar tissue, with significant correlations to clinical outcomes. This study confirms the importance of CMR in the management of cardiovascular diseases and suggests that further research and advancements are necessary to enhance its accessibility and utility in diverse healthcare settings. [ABSTRACT FROM AUTHOR]

Objective: To compare the effectiveness of low intra‐abdominal pressure (IAP) facilitated by deep neuromuscular block (NMB) to standard practice in improving the quality of recovery, preserving immune function, and enhancing parietal perfusion during robot‐assisted radical prostatectomy (RARP). Patients and Methods: In this blinded, randomised controlled trial, 96 patients were randomised to the experimental group with low IAP (8 mmHg) facilitated by deep NMB (post‐tetanic count 1–2) or the control group with standard IAP (14 mmHg) and moderate NMB (train‐of‐four 1–2). Recovery was measured using the 40‐item Quality of Recovery questionnaire and 36‐item Short‐Form Health survey. Immune function was evaluated by plasma damage‐associated molecular patterns, cytokines, and ex vivo lipopolysaccharide‐stimulated cytokine production. Parietal peritoneum perfusion was measured by analysing the recordings of indocyanine‐green injection. Results: Quality of recovery was not superior in the experimental group (n = 46) compared to the control group (n = 50). All clinical outcomes, including pain scores, postoperative nausea and vomiting, and hospital stay were similar. There were no significant differences in postoperative plasma concentrations of damage‐associated molecular patterns, cytokines, and ex vivo cytokine production capacity. The use of low IAP resulted in better parietal peritoneum perfusion. Conclusion: Despite better perfusion of the parietal peritoneum, low IAP facilitated by deep NMB did not improve the quality of recovery or preserve immune function compared to standard practice in patients undergoing RARP. [ABSTRACT FROM AUTHOR]

Background: Anastomotic leakage (AL) is a dreaded complication following colorectal cancer surgery, impacting patient outcome and leads to increasing healthcare consumption as well as economic burden. Bowel perfusion is a significant modifiable factor for anastomotic healing and thus crucial for reducing AL. Aims: The study aimed to calculate a cut-off value for quantified laser speckle perfusion units (LSPUs) in order to differentiate between ischemic and well-perfused tissue and to assess inter-observer reliability. Methods: LSCI was performed using a porcine ischemic small bowel loop model with the PerfusiX-Imaging® system. An ischemic area, a well-perfused area, and watershed areas, were selected based on the LSCI colormap. Subsequently, local capillary lactate (LCL) levels were measured. A logarithmic curve estimation tested the correlation between LSPU and LCL levels. A cut-off value for LSPU and lactate was calculated, based on anatomically ischemic and well-perfused tissue. Inter-observer variability analysis was performed with 10 observers. Results: Directly after ligation of the mesenteric arteries, differences in LSPU values between ischemic and well-perfused tissue were significant (p < 0.001) and increased significantly throughout all following measurements. LCL levels were significantly different (p < 0.001) at both 60 and 120 min. Logarithmic curve estimation showed an R2 value of 0.56 between LSPU and LCL values. A LSPU cut-off value was determined at 69, with a sensitivity of 0.94 and specificity of 0.87. A LCL cut-off value of 3.8 mmol/L was found, with a sensitivity and specificity of 0.97 and 1.0, respectively. There was no difference in assessment between experienced and unexperienced observers. Cohen's Kappa values were moderate to good (0.52–0.66). Conclusion: Real-time quantification of LSPUs may be a feasible intraoperative method to assess tissue perfusion and a cut-off value could be determined with high sensitivity and specificity. Inter-observer variability was moderate to good, irrespective of prior experience with the technique. [ABSTRACT FROM AUTHOR]

Mouse models of hindlimb ischemia (HLI) are used to study peripheral arterial disease and evaluate novel therapies. Contrast-enhanced ultrasound (CEUS) is a noninvasive perfusion measurement technique that is increasingly being employed in these models. The objective of this study was to evaluate two models of severe HLI by CEUS to characterize perfusion recovery and muscle perfusion patterns. Mice undergoing double femoral artery ligation were measured by CEUS and laser Doppler perfusion imaging (LDPI) at baseline and 1–150 d postsurgery. A second group undergoing femoral artery ligation and excision was measured 1–28 d postsurgery. By LDPI, both surgeries showed robust perfusion recovery by 14 d postsurgery. However, by CEUS only a ∼40% perfusion recovery plateau was reached in either group. These results are consistent with our previous work, employing a less severe single femoral artery ligation, that showed perfusion in the ischemic limb does not return to normal by 150 d postsurgery. Cluster analysis of muscle perfusion patterns indicated 3–5 different patterns at day 1 postsurgery. The double ligation model yielded significantly less variable perfusion patterns, suggesting that it can provide more reproducible results. Contrary to LDPI, perfusion as measured by CEUS never fully recovers after hindlimb surgery, even when followed 28–150 d postsurgery. Individual mice can manifest different patterns of muscle perfusion to the same surgery, but these patterns are conserved within and between different surgical techniques. These results may have significant implications for the evaluation of novel therapeutics to treat PAD in mice. [ABSTRACT FROM AUTHOR]

PURPOSE: Limitations from commercial software applications prevent the implementation of a robust and cost-efficient high-throughput cancer imaging radiomic feature extraction and perfusion analysis workflow. This study aimed to develop and validate a cancer research computational solution using open-source software for vendor- and sequence-neutral high-throughput image processing and feature extraction. METHODS: The Cancer Radiomic and Perfusion Imaging (CARPI) automated framework is a Python-based software application that is vendor- and sequence-neutral. CARPI uses contour files generated using an application of the user's choice and performs automated radiomic feature extraction and perfusion analysis. This workflow solution was validated using two clinical data sets, one consisted of 40 pelvic chondrosarcomas and 42 sacral chordomas with a total of 82 patients, and a second data set consisted of 26 patients with undifferentiated pleomorphic sarcoma (UPS) imaged at multiple points during presurgical treatment. RESULTS: Three hundred sixteen volumetric contour files were processed using CARPI. The application automatically extracted 107 radiomic features from multiple magnetic resonance imaging sequences and seven semiquantitative perfusion parameters from time-intensity curves. Statistically significant differences (P <.00047) were found in 18 of 107 radiomic features in chordoma versus chondrosarcoma, including six first-order and 12 high-order features. In UPS postradiation, the apparent diffusion coefficient mean increased 41% in good responders (P =.0017), while firstorder_10Percentile (P =.0312) was statistically significant between good and partial/nonresponders. CONCLUSION: The CARPI processing of two clinical validation data sets confirmed the software application's ability to differentiate between different types of tumors and help predict patient response to treatment on the basis of radiomic features. Benchmark comparison with five similar open-source solutions demonstrated the advantages of CARPI in the automated perfusion feature extraction, relational database generation, and graphic report export features, although lacking a user-friendly graphical user interface and predictive model building. CARPI is a Python-based automated software application that enables radiomics and perfusion analysis of different types of tumors. [ABSTRACT FROM AUTHOR]

Non-invasive perfusion imaging by Arterial spin labeling (ASL) can be advantageous at Ultra-high field (UHF) MRI, since the image SNR and the T1 relaxation time both increase with the static field. However, ASL implementation, especially at 7T, is not trivial. Especially for ASL, UHF MRI comes with many challenges, mainly due to B1+ inhomogeneities. This study aimed to investigate the effects of different transmit coil configurations on perfusion-weighted imaging at 7T using a flow-sensitive alternating inversion recovery (FAIR) technique with time-resolved frequency offset corrected inversion (TR-FOCI) pulses for labeling and background suppression. We conducted a performance comparison between a parallel transmit (pTx) system equipped with 32 receive (Rx) and 8 transmit (Tx) channels and a standard setup with 32Rx and 2Tx channels. Our findings demonstrate that the pTx system, characterized by a more homogeneous B1 transmit field, resulted in a significantly higher contrast-to-noise ratio, temporal signal-to-noise ratio, and lower coefficient of variance (CoV) than the standard 2Tx setup. Additionally, both setups demonstrated comparable capabilities for functional mapping of the hand region in the motor cortex, achieving reliable results within a short acquisition time of approximately 5 minutes. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions The objective of this systematic review and meta‐analysis was to pool randomized trials of patients undergoing left‐sided colorectal anastomosis, comparing the use of fluorescence perfusion imaging versus visual inspection in reducing anastomotic leaks.Databases searched included PubMed, Cochrane Library, Scopus, CINHAL (EBSCO), and Google Scholar based on the concepts: randomized, colorectal, anastomotic leak, and fluorescence imaging. The risk of bias was assessed using RoB2 and the certainty of the evidence with the GRADE Pro tool. The analysis used the log odds ratio for dichotomous data with 95% confidence intervals. Back‐transformation of the log odds to odds ratio was performed for the summary of findings. All syntheses used the Random‐effects model.Six randomized trials were included with 1949 patients and 204 events (leaks). Three trials included exclusively rectal cancer patients, while the other three involved benign and malignant pathologies of the sigmoid and rectum. The use of ostomy and preoperative radiation was variable. None of the studies had a high risk of bias. The pooled odds ratio for anastomotic leak reduction with Indocyanine Green (ICG) fluorescence was 0.586 (95% CI: 0.434–0.792). An absolute reduction of 4.7% in leak rates was observed, with no statistical heterogeneity (I2 = 0; p = 0.529). Due to clinical heterogeneity, the quality of evidence was rated moderate.The use of ICG is associated with reduced leak rates following left‐sided colorectal anastomosis with moderate confidence. ICG may be considered a standard of care given the clinically significant benefit in decreasing anastomotic leaks. [ABSTRACT FROM AUTHOR]

Estrogens regulate numerous physiological and pathological processes, including wide-ranging effects in wound healing. The effects of estrogens are mediated through multiple estrogen receptors (ERs), including the classical nuclear ERs (ERα and ER β ), that typically regulate gene expression, and the 7-transmembrane G protein-coupled estrogen receptor (GPER), that predominantly mediates rapid "non-genomic" signaling. Estrogen modulates the expression of various genes involved in epidermal function and regeneration, inflammation, matrix production, and protease inhibition, all critical to wound healing. Our previous work demonstrated improved myocutaneous wound healing in female mice compared to male mice. In the current study, we employed male and female GPER knockout mice to investigate the role of this estrogen receptor in wound revascularization and tissue viability. Using a murine myocutaneous flap model of graded ischemia, we measured real-time flap perfusion via laser speckle perfusion imaging. We conducted histologic and immunohistochemical analyses to assess skin and muscle viability, microvascular density and vessel morphology. Our results demonstrate that GPER is crucial in wound healing, mediating effects that are both dependent and independent of sex. Lack of GPER expression is associated with increased skin necrosis, reduced flap perfusion and altered vessel morphology. These findings contribute to understanding GPER signaling in wound healing and suggest possible therapeutic opportunities by targeting GPER. [ABSTRACT FROM AUTHOR]

Hypothalamus is a crucial deep brain area that is responsible for the integration and coordination of various brain functions. The altered perfusion of hypothalamus during headache caused by medication-overuse headache (MOH) was previously unknown. In the current study, the altered perfusion of hypothalamic subregions in MOH patients was investigated using state-of-the-art 3D pseudo-continuous arterial spin labeling (PCASL) MR imaging. In this study, 29 normal controls subjects (NCs) and 29 MOH patients underwent 3D PCASL and brain structural MR imaging. The hypothalamus was automatically segmented into 10 subunits and the volume of each subunit was automatically determined using Freesurfer software (v7.4.1). All segmented hypothalamic subunits were converted to individual hypothalamic subunit masks. The cerebral blood flow (CBF) images were coregistered with the raw brain structural images and resliced. The CBF value of each hypothalamic subunit was extracted from the warped CBF images. The volume and CBF value of each hypothalamic subunit were analyzed using the independent sample T test and Mann–Whitney U test, receiver operating characteristic (ROC) curve analysis, and Pearson and Spearman correlation analysis. Hypothalamic subunits with significantly decreased perfusion were located in the left posterior, left tubular superior, right anterior–inferior, right tubular inferior, right tubular superior, right posterior subunit and the entire right hypothalamus [CBF value for MOH vs NC (mL/100 g·min): 48.41 ± 6.75 vs 54.08 ± 11.47, 44.44 ± 4.79 vs 48.11 ± 7.73, 41.49 (32.90, 61.46) vs 49.38 ± 10.47, 46.62 ± 7.04 vs 53.90 ± 11.75, 42.12 ± 5.74 vs 47.02 ± 9.99, 42.79 ± 5.15 vs 47.93 ± 10.48 and 43.58 ± 5.06 vs 48.65 ± 9.33, respectively] in MOH compared to NC (P < 0.05). ROC analysis for these positive subunits revealed that area under the curve was 0.658–0.693, and ROC curve for left posterior subunit had the highest specificity of 93.10% while the entire right hypothalamus had the highest sensitivity of 72.41%. Further correlation analysis showed that the CBF value of the left posterior, right anterior–inferior, right tubular superior, whole right hypothalamus presented significantly negative correlation with Hamilton Depression Scale (HAMD) score (P < 0.05). Hypoperfusion of hypothalamic subunits may contribute to the understanding of MOH pathogenesis, and the 3D PCASL could be considered as a potential diagnostic and assessment tool for MOH. [ABSTRACT FROM AUTHOR]

Imaging-based selection has become integral in guiding endovascular thrombectomy for large vessel occlusive stroke, driven by positive trial outcomes incorporating parenchymal and perfusion imaging criteria. While small-moderate core trials transformed acute reperfusion therapy, uncertainties persisted for large ischemic strokes. This was recently addressed in several treatment trials which demonstrated a benefit of endovascular thrombectomy in patients with large ischemic strokes, defined by parenchymal and/or perfusion imaging. Although individual trials suggest treatment benefits regardless of core size, patient-level meta-analyses are essential to clarify this relationship. Our aim was to summarize the imaging ramifications of the major endovascular thrombectomy trials of the past decade focusing on the interaction between the core and the treatment effect, to assist in the design of future meta-analyses. The core-treatment relationship that will be investigated in these meta-anlalyses will likely have major implications in our systems of care designs and in determining the utility of imaging-based selection. [ABSTRACT FROM AUTHOR]

Introduction: Cerebral collateral circulation refers to the anastomoses that reroute the blood flow to the ischemic penumbra in the event of a large vessel occlusion (LVO). We aim to determine the utility of pre-mechanical-thrombectomy (MT) collateral scores in the early (<6 h from onset) versus extended (6–24 h from onset) window for MT with respect to a 3-month functional outcome, 3-month mortality, and early neurological improvement. Methods: We performed a retrospective chart review of patients who underwent MT for an anterior circulation LVO at a comprehensive stroke center from 7/2014 to 12/2020. A board-certified neuroradiologist, who was blinded to the clinical outcomes, used the collateral grading scales of Miteff (ordinal), Maas (ordinal), and modified-Tan (dichotomous) to designate collateral scores on the pre-MT CT Angiogram. The patients were divided into early (<6 h from onset) versus extended (6–24 h from onset) window groups depending on their timing of presentation to the emergency department. A regression analysis was performed, controlling for the baseline parameters, with the pre-MT collateral grading scores as predictors. The outcome measures were a good functional outcome (3-month mRS 0-2), mortality, and early neurological improvement. Results: A total of 220 patients met the inclusion criteria. In the overall cohort, the pre-MT scale of Maas was associated with a good functional outcome (OR, 0.58; 95% CI, 0.34–0.99; P 0.047) and mortality (OR, 0.55; 95% CI, 0.31–0.97; P 0.036). For the 162 patients who presented in the early window for MT, all of three pre-MT scales of Maas (OR, 0.39; 95% CI, 0.2–0.77; P 0.006), Miteff (OR, 0.43; 95% CI, 0.19–0.97; P 0.042) and modified-Tan (OR, 5.62; 95% CI, 1.16–27.37; P 0.033) were associated with a good functional outcome, whereas the Maas (OR, 0.48; 95% CI, 0.26–0.9; P 0.021) and the Miteff scale (OR, 0.4; 95% CI, 0.22–0.74; P 0.003) were associated with mortality. For the 58 patients who presented in the extended window for MT, none of the collateral grades were associated with functional outcome, mortality, or early neurological improvement. Conclusions: Our study demonstrates that while several collateral grades are helpful to predict outcomes in patients presenting in the early window, none of the pre-MT collateral scores were associated with outcomes in patients who presented in the extended window for MT. Thus, the current strategy of using perfusion imaging for the selection of patients for MT in the extended window should continue. [ABSTRACT FROM AUTHOR]

Background: Acute ischemic stroke is a leading cause of morbidity and mortality worldwide. Early and accurate imaging is crucial for effective management and improving patient outcomes. Functional MRI (fMRI) and CT perfusion imaging (CTP) are two advanced imaging modalities used to assess ischemic lesions. This study aims to compare the effectiveness and accuracy of fMRI and CTP in acute stroke management. Objective: To compare the effectiveness and accuracy of fMRI and CTP in acute stroke management, focusing on early detection, lesion characterization, and outcome prediction. Methods: A prospective cohort study was conducted on 100 patients presenting with acute ischemic stroke within 6 hours of symptom onset. Each patient underwent both fMRI and CTP imaging. Key metrics assessed included time to image acquisition, sensitivity, specificity, lesion detection and characterization, and predictive value for functional outcomes measured by the modified Rankin Scale (mRS) at 90 days. Results: The mean time from patient arrival to image acquisition was 30 minutes (±5) for fMRI and 25 minutes (±4) for CTP (p < 0.05). Sensitivity for detecting ischemic lesions was 95% for fMRI and 90% for CTP, while specificity was 92% for fMRI and 88% for CTP (p < 0.05). fMRI detected 120 lesions compared to 110 by CTP and characterized penumbra versus core infarct in 90% of cases compared to 85% for CTP (p < 0.05). The correlation coefficient for predicting functional outcomes was 0.85 for fMRI and 0.80 for CTP (p < 0.01). Functional independence (mRS 0-2) was achieved in 60% of fMRI patients and 55% of CTP patients (p < 0.05). Conclusion: Both fMRI and CTP are effective in acute stroke management. However, fMRI showed higher sensitivity, specificity, superior lesion detection and characterization, and better predictive value for functional outcomes. fMRI may be a more reliable tool for early stroke assessment, though CTP remains a valuable alternative when fMRI is not available. [ABSTRACT FROM AUTHOR]

Background: Due to insufficient near‐field resolution and artifacts, it is challenging to evaluate the left ventricular apical perfusion with phased‐array probes. By combining high‐frequency linear probe and contrast‐enhanced ultrasound (CEUS), imaging of apical myocardial perfusion could be improved. The study aims to evaluate the preliminary application of CEUS by high‐frequency linear probes to assess the apical perfusion. Methods: The study enrolled retrospectively 91 patients to test the feasibility of the novel method. In protocol 1, patients were stratified into a group with left anterior descending artery (LAD) stenosis (N = 40) and a group without LAD stenosis or coronary artery disease (N = 41) based on the degree of coronary artery narrowing, quantified by >50% stenosis in coronary angiography. Receiver operating characteristics (ROC) analysis was performed to test the diagnostic value of perfusion parameters. In protocol 2, the reproducibility of high‐frequency linear probe in apical perfusion analysis was compared with the conventional phased‐array probe in 30 patients. Results: (1) The novel method is feasible in 81(89.01%) patients. (2) In protocol 1, to detect LAD stenosis, the best cut‐off of β, T, A, and MBF were 10.32, 3.28, 9.39, and 4.99, respectively. Area under the curve of β, T, A, and MBF were.880,.881,.761, and.880, respectively. (3) In protocol 2, compared with phased‐array probe, the quantitative analysis of high‐frequency linear probe is of high reproducibility and could get good curve fitting (R2 =.29 vs. R2 =.71, P <.01). Conclusion: Observation of apical perfusion using this method is feasible and quantitative analysis allows an accurate and convenient identification of LAD stenosis. This method provides an alternative for patients who have difficulties in visualizing the apical region with a phased‐array probe. [ABSTRACT FROM AUTHOR]

Background: Delayed cerebral ischemia associated with cerebral vasospasm (CVS) in aneurysmal subarachnoid hemorrhage significantly affects patient prognosis. Levosimendan has emerged as a potential treatment, but clinical data are lacking. The aim of this study is to decipher levosimendan's effect on cerebral hemodynamics by automated quantitative measurements of brain computed tomography perfusion (CTP). Methods: We conducted a retrospective analysis of a database of a neurosurgical intensive care unit. All patients admitted from January 2018 to July 2022 for aneurysmal subarachnoid hemorrhage and treated with levosimendan for CVS who did not respond to other therapies were included. Quantitative measurements of time to maximum (Tmax), relative cerebral blood volume (rCBV), and relative cerebral blood flow (rCBF) were automatically compared with coregistered CTP before and after levosimendan administration in oligemic regions. Results: Of 21 patients included, CTP analysis could be performed in 16. Levosimendan improved Tmax from 14.4 s (interquartile range [IQR] 9.1–21) before treatment to 7.1 s (IQR 5.5–8.1) after treatment (p < 0.001). rCBV (94% [IQR 79–103] before treatment and 89% [IQR 72–103] after treatment, p = 0.63) and rCBF (85% [IQR 77–90] before treatment and 87% [IQR 73–98] after treatment, p = 0.98) remained stable. The subgroup of six patients who did not develop cerebral infarction attributed to delayed cerebral ischemia showed an approximately 10% increase (rCBV 85% [IQR 79–99] before treatment vs. 95% [IQR 88–112] after treatment, p = 0.21; rCBF 81% [IQR 76–87] before treatment vs. 89% [IQR 84–99] after treatment, p = 0.4). Conclusions: In refractory CVS, levosimendan use was associated with a significant reduction in Tmax in oligemic regions. However, this value remained at an abnormal level, indicating the presence of a persistent CVS. Further analysis raised the hypothesis that levosimendan causes cerebral vasodilation, but other studies are needed because our design does not allow us to quantify the effect of levosimendan from that of the natural evolution of CVS. [ABSTRACT FROM AUTHOR]

Background: Microvascular scarring compromises the functionality of the endometrium, and vascular flow at the junctional zone (JZ) may be the key to understanding poor reproductive outcomes in women with Asherman syndrome (AS). Aims: To investigate whether vascular perfusion of the uterus, measured by dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) is impaired in women with intrauterine adhesions (IUA) and AS. Materials and Methods: A prospective observational cohort pilot study of 23 women with IUA treated with hysteroscopic synecholysis and a control group of two patients with cervix cancer were subject to DCE‐MRI with gadolinium to assess uterine vascularity. Twelve regions of interest (ROIs) were allocated on the DCE‐MRI image incorporating the JZ, with control ROI placed at the psoas muscle. Individual ROIs were compared to the mean total perfusion (TP) in the same uterus. Pre‐ and post‐operative perfusion analyses were performed on five women. Receiver operator curves (ROC) were used to analyse MRI as a predictor of IUA. Results: There was no significant difference in perfusion; a trend toward reduced perfusion was observed in women with IUA compared to the controls. The ROC was predictive of higher‐grade and inoperable IUA. Conclusions: Reduced perfusion on DCE‐MRI as assessed by ROC predicted higher‐stage AS. The results of this study support further investigation of DCE‐MRI as a prognostic tool for AS prior to surgical intervention to assist in providing prognostic guidance for women suffering from AS. [ABSTRACT FROM AUTHOR]

Colorectal cancer remains a major cause of cancer death and morbidity worldwide. Surgery is a major treatment modality for primary and, increasingly, secondary curative therapy. However, with more patients being diagnosed with early stage and premalignant disease manifesting as large polyps, greater accuracy in diagnostic and therapeutic precision is needed right from the time of first endoscopic encounter. Rapid advancements in the field of artificial intelligence (AI), coupled with widespread availability of near infrared imaging (currently based around indocyanine green (ICG)) can enable colonoscopic tissue classification and prognostic stratification for significant polyps, in a similar manner to contemporary dynamic radiological perfusion imaging but with the advantage of being able to do so directly within interventional procedural time frames. It can provide an explainable method for immediate digital biopsies that could guide or even replace traditional forceps biopsies and provide guidance re margins (both areas where current practice is only approximately 80% accurate prior to definitive excision). Here, we discuss the concept and practice of AI enhanced ICG perfusion analysis for rectal cancer surgery while highlighting recent and essential near-future advancements. These include breakthrough developments in computer vision and time series analysis that allow for real-time quantification and classification of fluorescent perfusion signals of rectal cancer tissue intraoperatively that accurately distinguish between normal, benign, and malignant tissues in situ endoscopically, which are now undergoing international prospective validation (the Horizon Europe CLASSICA study). Next stage advancements may include detailed digital characterisation of small rectal malignancy based on intraoperative assessment of specific intratumoral fluorescent signal pattern. This could include T staging and intratumoral molecular process profiling (e.g. regarding angiogenesis, differentiation, inflammatory component, and tumour to stroma ratio) with the potential to accurately predict the microscopic local response to nonsurgical treatment enabling personalised therapy via decision support tools. Such advancements are also applicable to the next generation fluorophores and imaging agents currently emerging from clinical trials. In addition, by providing an understandable, applicable method for detailed tissue characterisation visually, such technology paves the way for acceptance of other AI methodology during surgery including, potentially, deep learning methods based on whole screen/video detailing. [ABSTRACT FROM AUTHOR]

The delivery of human adipose-derived stromal cells (hASCs) to ischemic tissues represents a promising strategy to promote vascular regeneration for patients with critical limb ischemia (CLI). Building on previous work, this study focused on the in vivo characterization of a hydrogel cell delivery platform for hASCs composed of peptide-functionalized methacrylated glycol chitosan and a terminally acrylated triblock copolymer of poly(ethylene glycol) and poly(trimethylene carbonate) [PEG(PTMC-A)2] in athymic nu/nu mice with femoral artery ligation-induced CLI (FAL-CLI). This immunodeficient mouse strain was selected to enable human cell transplantation in a model with conserved monocyte/macrophage function, recognizing that macrophages are key regulators of the biomaterial implant response, as well as vascular repair and regeneration. The hASCs were engineered to coexpress tdTomato and firefly luciferase to enable longitudinal cell tracking using bioluminescence imaging. Interestingly, the hASCs were better retained following delivery in saline compared with hydrogel delivery. However, laser Doppler perfusion imaging analysis indicated that the restoration of hindlimb perfusion was similar between the two cell treatment groups. Critically, delivery of the hASCs within the hydrogels was associated with adverse outcomes only observed within this treatment group, including severe swelling, discoloration, and necrosis, which necessitated early euthanasia of some mice. CD45 staining supported that the combination of the cells and hydrogels induced an inflammatory host response. These findings contrast with previous positive results when the platform was tested for hASC delivery in more severely immunocompromised NOD/SCID mice with FAL-CLI, as well as allogeneic rat ASC delivery in a healthy immunocompetent rat model. Overall, this study emphasizes the potential importance of testing cell delivery platforms in preclinical disease models that have retained host immune cell function, especially for immunomodulatory cell populations such as ASCs. [ABSTRACT FROM AUTHOR]

Intravenous tenecteplase increases reperfusion in patients with salvageable brain tissue on perfusion imaging and might have advantages over alteplase as a thrombolytic for ischaemic stroke. We aimed to assess the non-inferiority of tenecteplase versus alteplase on clinical outcomes in patients selected by use of perfusion imaging. This international, multicentre, open-label, parallel-group, randomised, clinical non-inferiority trial enrolled patients from 35 hospitals in eight countries. Participants were aged 18 years or older, within 4·5 h of ischaemic stroke onset or last known well, were not being considered for endovascular thrombectomy, and met target mismatch criteria on brain perfusion imaging. Patients were randomly assigned (1:1) by use of a centralised web server with randomly permuted blocks to intravenous tenecteplase (0·25 mg/kg) or alteplase (0·90 mg/kg). The primary outcome was the proportion of patients without disability (modified Rankin Scale 0–1) at 3 months, assessed via masked review in both the intention-to-treat and per-protocol populations. We aimed to recruit 832 participants to yield 90% power (one-sided alpha=0·025) to detect a risk difference of 0·08, with an absolute non-inferiority margin of −0·03. The trial was registered with the Australian New Zealand Clinical Trials Registry, ACTRN12613000243718, and the European Union Clinical Trials Register, EudraCT Number 2015-002657-36, and it is completed. Recruitment ceased early following the announcement of other trial results showing non-inferiority of tenecteplase versus alteplase. Between March 21, 2014, and Oct 20, 2023, 680 patients were enrolled and randomly assigned to tenecteplase (n=339) and alteplase (n=341), all of whom were included in the intention-to-treat analysis (multiple imputation was used to account for missing primary outcome data for five patients). Protocol violations occurred in 74 participants, thus the per-protocol population comprised 601 people (295 in the tenecteplase group and 306 in the alteplase group). Participants had a median age of 74 years (IQR 63–82), baseline National Institutes of Health Stroke Scale score of 7 (4–11), and 260 (38%) were female. In the intention-to-treat analysis, the primary outcome occurred in 191 (57%) of 335 participants allocated to tenecteplase and 188 (55%) of 340 participants allocated to alteplase (standardised risk difference [SRD]=0·03 [95% CI −0·033 to 0·10], one-tailed p non-inferiority =0·031). In the per-protocol analysis, the primary outcome occurred in 173 (59%) of 295 participants allocated to tenecteplase and 171 (56%) of 306 participants allocated to alteplase (SRD 0·05 [−0·02 to 0·12], one-tailed p non-inferiority =0·01). Nine (3%) of 337 patients in the tenecteplase group and six (2%) of 340 in the alteplase group had symptomatic intracranial haemorrhage (unadjusted risk difference=0·01 [95% CI −0·01 to 0·03]) and 23 (7%) of 335 and 15 (4%) of 340 died within 90 days of starting treatment (SRD 0·02 [95% CI −0·02 to 0·05]). The findings in our study provide further evidence to strengthen the assertion of the non-inferiority of tenecteplase to alteplase, specifically when perfusion imaging has been used to identify reperfusion-eligible stroke patients. Although non-inferiority was achieved in the per-protocol population, it was not reached in the intention-to-treat analysis, possibly due to sample size limtations. Nonetheless, large-scale implementation of perfusion CT to assist in patient selection for intravenous thrombolysis in the early time window was shown to be feasible. Australian National Health Medical Research Council; Boehringer Ingelheim. [ABSTRACT FROM AUTHOR]

Simple Summary: The identification of gliomas and the differentiation between different types is essential to evaluate patients' prognosis and guide optimal clinical management. The ideal multiparametric magnetic resonance imaging (MRI) protocol for the assessment of gliomas is a current topic of research. This study aimed to explore the performance of dynamic contrast-enhanced (DCE) MRI and diffusion kurtosis imaging (DKI) in differentiating molecular subtypes of adult-type diffuse gliomas. The results showed that a combined evaluation of DCE-MRI and DKI parameters reveals the best prediction of high-grade vs. low-grade gliomas, IDH1/2 wildtype vs. mutated gliomas, and astrocytomas/glioblastomas vs. oligodendrogliomas. The aim was to explore the performance of dynamic contrast-enhanced (DCE) MRI and diffusion kurtosis imaging (DKI) in differentiating the molecular subtypes of adult-type gliomas. A multicenter MRI study with standardized imaging protocols, including DCE-MRI and DKI data of 81 patients with WHO grade 2–4 gliomas, was performed at six centers. The DCE-MRI and DKI parameter values were quantitatively evaluated in ROIs in tumor tissue and contralateral normal-appearing white matter. Binary logistic regression analyses were performed to differentiate between high-grade (HGG) vs. low-grade gliomas (LGG), IDH1/2 wildtype vs. mutated gliomas, and high-grade astrocytic tumors vs. high-grade oligodendrogliomas. Receiver operating characteristic (ROC) curves were generated for each parameter and for the regression models to determine the area under the curve (AUC), sensitivity, and specificity. Significant differences between tumor groups were found in the DCE-MRI and DKI parameters. A combination of DCE-MRI and DKI parameters revealed the best prediction of HGG vs. LGG (AUC = 0.954 (0.900–1.000)), IDH1/2 wildtype vs. mutated gliomas (AUC = 0.802 (0.702–0.903)), and astrocytomas/glioblastomas vs. oligodendrogliomas (AUC = 0.806 (0.700–0.912)) with the lowest Akaike information criterion. The combination of DCE-MRI and DKI seems helpful in predicting glioma types according to the 2021 World Health Organization's (WHO) classification. [ABSTRACT FROM AUTHOR]

Imaging the heart is one of the most technically challenging applications of Computed Tomography (CT) due to the presence of cardiac motion limiting optimal visualization of small structures such as the coronary arteries. Electrocardiographic gating during CT data acquisition facilitates motion free imaging of the coronary arteries. Since publishing the first version of the Canadian Association of Radiologists (CAR) cardiac CT guidelines, many technological advances in CT hardware and software have emerged necessitating an update. The goal of these cardiac CT practice guidelines is to present an overview of the current evidence supporting the use of cardiac CT in various clinical scenarios and to outline standards of practice for patient safety and quality of care when establishing a cardiac CT program in Canada. [ABSTRACT FROM AUTHOR]

Purpose: The presurgical discrimination of IDH-mutant astrocytoma grade 4 from IDH-wildtype glioblastoma is crucial for patient management, especially in younger adults, aiding in prognostic assessment, guiding molecular diagnostics and surgical planning, and identifying candidates for IDH-targeted trials. Despite its potential, the full capabilities of DSC-PWI remain underexplored. This research evaluates the differentiation ability of relative-cerebral-blood-volume (rCBV) percentile values for the enhancing and non-enhancing tumor regions compared to the more commonly used mean or maximum preselected rCBV values. Methods: This retrospective study, spanning 2016–2023, included patients under 55 years (age threshold based on World Health Organization recommendations) with grade 4 astrocytic tumors and known IDH status, who underwent presurgical MR with DSC-PWI. Enhancing and non-enhancing regions were 3D-segmented to calculate voxel-level rCBV, deriving mean, maximum, and percentile values. Statistical analyses were conducted using the Mann-Whitney U test and AUC-ROC. Results: The cohort consisted of 59 patients (mean age 46; 34 male): 11 astrocytoma-4 and 48 glioblastoma. While glioblastoma showed higher rCBV in enhancing regions, the differences were not significant. However, non-enhancing astrocytoma-4 regions displayed notably higher rCBV, particularly in lower percentiles. The 30th rCBV percentile for non-enhancing regions was 0.705 in astrocytoma-4, compared to 0.458 in glioblastoma (p = 0.001, AUC-ROC = 0.811), outperforming standard mean and maximum values. Conclusion: Employing an automated percentile-based approach for rCBV selection enhances differentiation capabilities, with non-enhancing regions providing more insightful data. Elevated rCBV in lower percentiles of non-enhancing astrocytoma-4 is the most distinguishable characteristic and may indicate lowly vascularized infiltrated edema, contrasting with glioblastoma's pure edema. [ABSTRACT FROM AUTHOR]

Introduction: Dynamic susceptibility contrast (DSC) perfusion weighted (PW)-MRI can aid in differentiating treatment related abnormalities (TRA) from tumor progression (TP) in post-treatment glioma patients. Common methods, like the 'hot spot', or visual approach suffer from oversimplification and subjectivity. Using perfusion of the complete lesion potentially offers an objective and accurate alternative. This study aims to compare the diagnostic value and assess the subjectivity of these techniques. Methods: 50 Glioma patients with enhancing lesions post-surgery and chemo-radiotherapy were retrospectively included. Outcome was determined by clinical/radiological follow-up or biopsy. Imaging analysis used the 'hot spot', volume of interest (VOI) and visual approach. Diagnostic accuracy was compared using receiving operator characteristics (ROC) curves for the VOI and 'hot spot' approach, visual assessment was analysed with contingency tables. Inter-operator agreement was determined with Cohens kappa and intra-class coefficient (ICC). Results: 29 Patients suffered from TP, 21 had TRA. The visual assessment showed poor to substantial inter-operator agreement (κ = -0.72 – 0.68). Reliability of the 'hot spot' placement was excellent (ICC = 0.89), while reference placement was variable (ICC = 0.54). The area under the ROC (AUROC) of the mean- and maximum relative cerebral blood volume (rCBV) (VOI-analysis) were 0.82 and 0.72, while the rCBV-ratio ('hot spot' analysis) was 0.69. The VOI-analysis had a more balanced sensitivity and specificity compared to visual assessment. Conclusions: VOI analysis of DSC PW-MRI data holds greater diagnostic accuracy in single-moment differentiation of TP and TRA than 'hot spot' or visual analysis. This study underlines the subjectivity of visual placement and assessment. [ABSTRACT FROM AUTHOR]

Objective: Presurgical differentiation between astrocytomas and oligodendrogliomas remains an unresolved challenge in neuro-oncology. This research aims to provide a comprehensive understanding of each tumor's DSC-PWI signatures, evaluate the discriminative capacity of cerebral blood volume (CBV) and percentage of signal recovery (PSR) percentile values, and explore the synergy of CBV and PSR combination for pre-surgical differentiation. Methods: Patients diagnosed with grade 2 and 3 IDH-mutant astrocytomas and IDH-mutant 1p19q-codeleted oligodendrogliomas were retrospectively retrieved (2010–2022). 3D segmentations of each tumor were conducted, and voxel-level CBV and PSR were extracted to compute mean, minimum, maximum, and percentile values. Statistical comparisons were performed using the Mann-Whitney U test and the area under the receiver operating characteristic curve (AUC-ROC). Lastly, the five most discriminative variables were combined for classification with internal cross-validation. Results: The study enrolled 52 patients (mean age 45-year-old, 28 men): 28 astrocytomas and 24 oligodendrogliomas. Oligodendrogliomas exhibited higher CBV and lower PSR than astrocytomas across all metrics (e.g., mean CBV = 2.05 and 1.55, PSR = 0.68 and 0.81 respectively). The highest AUC-ROCs and the smallest p values originated from CBV and PSR percentiles (e.g., PSRp70 AUC-ROC = 0.84 and p value = 0.0005, CBVp75 AUC-ROC = 0.8 and p value = 0.0006). The mean, minimum, and maximum values yielded lower results. Combining the best five variables (PSRp65, CBVp70, PSRp60, CBVp75, and PSRp40) achieved a mean AUC-ROC of 0.87 for differentiation. Conclusions: Oligodendrogliomas exhibit higher CBV and lower PSR than astrocytomas, traits that are emphasized when considering percentiles rather than mean or extreme values. The combination of CBV and PSR percentiles results in promising classification outcomes. Clinical relevance statement: The combination of histogram-derived percentile values of cerebral blood volume and percentage of signal recovery from DSC-PWI enhances the presurgical differentiation between astrocytomas and oligodendrogliomas, suggesting that incorporating these metrics into clinical practice could be beneficial. Key Points: • The unsupervised selection of percentile values for cerebral blood volume and percentage of signal recovery enhances presurgical differentiation of astrocytomas and oligodendrogliomas. • Oligodendrogliomas exhibit higher cerebral blood volume and lower percentage of signal recovery than astrocytomas. • Cerebral blood volume and percentage of signal recovery combined provide a broader perspective on tumor vasculature and yield promising results for this preoperative classification. [ABSTRACT FROM AUTHOR]

Objectives: It is unclear which selection strategy, plain CT vs. CT perfusion (CTP), is more powerful in predicting outcome after mechanical thrombectomy (MT). We aimed to compare the effect of plain CT and CTP in predicting outcome after MT within 6 h. Methods: We conducted a prospective analysis of a retrospective cohort from our single-center study, which had occlusion of the internal carotid artery and middle cerebral artery up to the proximal M2 segment and received MT within 6 h. According to the Alberta Stroke Program Early CT Score (ASPECTS), patients were divided into a high-ASPECTS group (≥ 6) and a low ASPECTS group (< 6). Similarly, patients were divided into mismatch and no-mismatch groups according to the DEFUSE3 criteria for CTP. A good outcome was defined as a 90-day modified Rankin Scale (mRS) score of ≤ 3. Univariate and binary logistic regression analyses were used to investigate the association between different imaging modality and 90-day mRS score, and mortalities, respectively. Results: The high ASPECTS group included 307 patients (89.2%). The mismatch group included 189 (54.9%) patients meeting the DEFUSE3 criterion. Compared to the low ASPECTS group, the high ASPECTS group had a good outcome (odds ratio (OR), 2.285; [95% confidence interval (CI) (1.106, 4.723)], p = 0.026) and lower mortality (OR, 0.350; [95% CI (0.163, 0.752)], p = 0.007). However, there were no significant differences in good outcomes and mortality between the mismatch and no-mismatch groups. Conclusions: Compared with plain CT, CTP does not provide additional benefits in the selection of patients suitable for MT within 6 h. Clinical relevance statement: CT perfusion is not superior to plain CT for the prediction of clinical outcomes when selecting patients for mechanical thrombectomy in the first 6 h. In that clinical setting, plain CT may be safe in the absence of perfusion data. Key Points: • The advantage of CT perfusion (CTP) over CT in pre-mechanical thrombectomy (MT) screening has not been proven for patients with a large infarct core. • CTP is not better than plain CT in predicting good outcome following MT within 6 h. • Plain CT is sufficient for selecting patients suitable for MT within 6 h of large artery occlusion. [ABSTRACT FROM AUTHOR]

Background: Full‐thickness skin grafts are widely used in plastic and reconstructive surgery. The main limitation of skin grafting is the poor textural durability and associated contracture, which often needs further corrective surgery. Excessive inflammation is the main reason for skin graft contractions, which involve overactivation of myofibroblasts. These problems have prompted the development of new therapeutic approaches, including macrophage polarization modulation and stem cell–based therapies. Currently, adipose‐derived stem cells (ASCs) have shown promise in promoting skin grafts survival and regulating macrophage phenotypes. However, the roles of ASCs on macrophages in decreasing skin grafts contraction remain unknown. Materials and Methods: Rat adipose‐derived stem cells (rASCs) were isolated from rat inguinal adipose tissues. Full‐thickness skin graft model was constructed on male rats divided into control group and rASCs treatment group. Skin graft was assessed for concentration, elasticity modulus and stiffness. Rat bone marrow‐derived macrophages (rBMDMs) were isolated from rat femurs, and subsequent RT‐qPCR and coculture assays were carried out to explore the cellular mechanisms. Immunohistochemical and immunofluorescence staining were used to verify mechanisms in vivo. Results: In vivo results showed that after injection of ASCs, improved texture, increased survival and inhibited contraction of skin grafts were seen. Vascularization was also improved as illustrated by laser perfusion image and vascular endothelial growth factor (VEGF) concentration. Histological analysis revealed that ASCs injection significantly reduced expression of pro‐inflammatory cytokines (TNF‐a, IL‐1β) and increased expression of anti‐inflammatory (IL‐10) and pro‐healing cytokines (IGF‐1). At cellular level, after co‐culturing with rASCs, rat bone marrow derived macrophages (rBMDMs) favored M2 polarization even under inflammatory stimulus. Conclusion: ASCs treatment enhanced vascularization via angiogenic cytokines secretion and alleviated inflammatory environment in skin grafts by driving M2 macrophages polarization, which improved survival and decreased skin grafts contraction. Our work showed that ASCs transplantation can be harnessed to enhance therapeutic efficacy of skin grafting in cutaneous defects treatment. [ABSTRACT FROM AUTHOR]

Purpose: Many rural Australian hospitals lack on‐site computed tomography (CT). These hospitals often refer patients to local off‐site private radiology clinics or to central hospitals, challenging the achievement of time‐sensitive scans. For stroke patients, timely access to CT affects treatment options. This study questions whether on‐site CT matters in rural hospitals by investigating stroke patients' door‐to‐scan‐time (DTST) and CT scan sequence referrals. Method: A retrospective chart audit was completed across four rural hospitals; two with on‐site CT and two without. Adult emergency stroke presentations were randomly sampled. Comparisons between on‐site and off‐site CT hospitals were made for DTST and CT sequence referrals using Mann–Whitney U‐tests and Fisher's exact tests. Results: A total of 120 charts were audited (on‐site CT, n = 60; off‐site CT, n = 60). DTST was longer for off‐site vs. on‐site CT hospitals (median = 4.30 h vs. median = 0.70 h; U = 338, p < 0.001) regardless of whether presentations occurred in business hours or out of hours (p < 0.001). Off‐site CT hospitals ordered less CT angiography or perfusion scanning (32% vs. 85%, p < 0.001). Conclusions: Off‐site CT hospital patients had longer DTST and received less angiography or perfusion scanning. These findings suggest that on‐site CT matters to rural stroke patients by improving equitable access to CT and appropriate scan referrals. [ABSTRACT FROM AUTHOR]

Background: The effect of imaging selection modality on endovascular thrombectomy (EVT) clinical outcomes in patients with acute ischemic stroke due to large vessel occlusion (AIS‐LVO) remains unclear. This study aims to compare post‐EVT outcomes in patients with AIS‐LVO who underwent basic imaging (computed tomography with or without computed tomography angiography) and advanced imaging (computed tomography perfusion or magnetic resonance imaging) in early and late time windows. Method: A systematic literature search was conducted on PubMed, Cochrane Library, and Embase databases from inception until June 10, 2023. Studies investigating the relationship between the imaging selection modality and post‐EVT outcomes in patients with AIS‐LVO were retrieved. A random‐effects model was used to pool the effect estimates of successful reperfusion, symptomatic intracranial hemorrhage (sICH), functional independence, and mortality. The meta‐analysis was performed using Review Manager software v.4.3, and the outcomes were assessed using odds ratios (ORs) and 95% confidence intervals (CIs). Result: A total of 13 non‐randomized observational studies, comprising 19,694 patients, were included in this meta‐analysis. In the early time windows, AIS‐LVO patients receiving advanced imaging demonstrated a higher likelihood of functional independence (OR, 1.25, 95% CI, 1.08–1.46) and a lower risk of mortality (OR,.73 95% CI,.61–.86) compared to those receiving basic imaging. In the extended time windows, AIS‐LVO patients undergoing advanced imaging had a lower mortality rate (OR,.79, 95% CI,.68–.92). Regardless of the time of onset, there were no significant differences between the two groups in terms of sICH or successful reperfusion. Conclusion: Advanced imaging combined with EVT may achieve better clinical outcomes in patients with AIS‐LVO. Further high‐quality studies are needed to validate these findings. [ABSTRACT FROM AUTHOR]

Background: Quantitative transport mapping (QTM) of blood velocity, based on the transport equation has been demonstrated higher accuracy and sensitivity of perfusion quantification than the traditional Kety's method-based cerebral blood flow (CBF). This study aimed to investigate the associations between QTM velocity and cognitive function in Alzheimer's disease (AD) using multiple post-labeling delay arterial spin labeling (ASL) MRI. Methods: A total of 128 subjects (21 normal controls (NC), 80 patients with mild cognitive impairment (MCI), and 27 AD) were recruited prospectively. All participants underwent MRI examination and neuropsychological evaluation. QTM velocity and traditional CBF maps were computed from multiple delay ASL. Regional quantitative perfusion measurements were performed and compared to study group differences. We tested the hypothesis that cognition declines with reduced cerebral blood perfusion with consideration of age and gender effects. Results: In cortical gray matter (GM) and the hippocampus, QTM velocity and CBF showed decreased values in the AD group compared to NC and MCI groups; QTM velocity, but not CBF, showed a significant difference between MCI and NC groups. QTM velocity and CBF showed values decreasing with age; QTM velocity, but not CBF, showed a significant gender difference between male and female. QTM velocity and CBF in the hippocampus were positively correlated with cognition, including global cognition, memory, executive function, and language function. Conclusion: This study demonstrated an increased sensitivity of QTM velocity as compared with the traditional Kety's method-based CBF. Specifically, we observed only in QTM velocity, reduced perfusion velocity in GM and the hippocampus in MCI compared with NC. Both QTM velocity and CBF demonstrated a reduction in AD vs. controls. Decreased QTM velocity and CBF in the hippocampus were correlated with poor cognitive measures. These findings suggest QTM velocity as potential biomarker for early AD blood perfusion alterations and it could provide an avenue for early intervention of AD. [ABSTRACT FROM AUTHOR]

Introduction: At our institution, revascularization after indirect moyamoya surgery is routinely evaluated using magnetic resonance angiography (MRA) rather than catheter angiography. In this paper, we review how revascularization can be visualized on axial MRA and compare its visualization on MRA to that on catheter angiography. We also compare clinical outcomes of patients followed with routine postoperative MRA with outcomes of patients followed with routine catheter angiography. Methods: We retrospectively reviewed the records of all patients treated at our institution who underwent unilateral encephaloduroarteriosynangiosis (EDAS) and/or pial synangiosis between the ages of 1 and 21 years and between December 31, 2003, and May 1, 2021. We included patients who underwent EDAS/pial synangiosis at other hospitals as long as they met all inclusion criteria. Inclusion criteria included having a preoperative MRA within 18 months of surgery and a postoperative MRA 3−30 months after surgery. Clinical outcomes included development of postoperative stroke and transient ischemic attacks (TIAs) and changes in symptoms (improved, unchanged, or worsened), including seizures, balance issues, and headaches. Clinical outcomes were compared between patients who had routine postoperative MRA only versus those who had routine postoperative angiograms, with or without routine MRA. For each surgery, we determined the ratios of the diameters and areas of the donor vessel and the contralateral corresponding vessel, as well as the relative signal intensities of these two vessels, on preoperative and 3- to 30-month postoperative MRA. We did the same for the middle meningeal artery (MMA) ipsilateral to the donor artery and the contralateral MMA. We assessed changes from pre- to post-operation in diameter ratios, area ratios, relative signal intensity, ivy sign, and in brain perfusion on arterial spin labeled (ASL) imaging. MRI and MRA measures of revascularization and flow were compared to Matsushima grades in patients who had postoperative catheter angiograms. Results: Fifty-one operations for 42 unique patients were included. There were no significant differences in the rates of postoperative strokes, postoperative TIAs, changes in symptoms, or new symptoms after surgeries evaluated by routine postoperative MRA versus catheter angiogram (p = 0.282, 1, 0.664, and 0.727, respectively). There were significant associations between greater collateralization on postoperative MRA and greater median increases in preoperative-to-postoperative ratios of donor-vessel-over-contralateral-vessel diameter (p = 0.0461), ipsilateral-MMA-over-contralateral-MMA diameter (p = 0.0135), and the summed donor and ipsilateral MMA diameters over the summed contralateral vessel diameters (p < 0.001). The median increase in the ratio of the donor vessel and contralateral corresponding vessel diameters was significantly higher for Matsushima grade A versus B (p = 0.036). The median increase in the ratio of the sum of donor and ipsilateral MMA diameters over the sum of the contralateral vessel diameters was significantly higher for improved-versus-unchanged perfusion on ASL imaging (p = 0.0074). There was a nonsignificant association between greater postoperative collateralization on MRA and Matsushima grade (p = 0.1160). Conclusion: Cerebral revascularization after EDAS and pial synangiosis can be evaluated on axial MRA by comparing the diameter and/or signal intensity of the donor vessel and corresponding contralateral vessel, as well as the ipsilateral and contralateral MMA, on postoperative-versus-preoperative MRA. The use of routine postoperative MRA rather than catheter angiography does not appear to negatively affect outcomes. [ABSTRACT FROM AUTHOR]

Background: This study explores the predictive value of Computerized Tomography (CT) perfusion imaging, serum D-dimer (D-D), and serum matrix metalloproteinase-9 (MMP-9) levels for hemorrhagic transformation (HT) in patients with acute cerebral infarction post-thrombolysis. Materials and Methods: Patients with acute cerebral infarction who underwent thrombolytic therapy from February 2021 to February 2022 were included. CT perfusion imaging was conducted within a week post-operation. The study compared CT perfusion parameters and serum markers, analyzing differences and conducting univariate and multivariate analyses to explore their predictive value for HT. Results: No significant differences were found in hypertension, hyperlipidemia, stroke history, mean arterial pressure, fasting blood glucose, and platelet count pre-thrombolysis (P > 0.05). However, infarct diameter = 5 cm and atrial fibrillation were more common in the study group, with higher pre-thrombolysis National Institutes of Health Stroke Scale (NIHSS) score, D-D, and MMP-9 levels (P < 0.05). CT perfusion showed lower relative cerebral blood volume (rCBV, relative cerebral blood flow (rCBF, and higher relative mean transit time (rMTT), relative time to peak (rTTP) in the study group (P < 0.05). D-D and MMP-9 levels were negatively correlated with rCBV, rCBF, and positively with rTTP, CTP integration index (P < 0.05). Conclusion: CT perfusion imaging, serum D-D, and MMP-9 levels are effective predictors of hemorrhagic transformation in acute cerebral infarction patients postthrombolysis. These findings are valuable for guiding clinical treatment and monitoring. [ABSTRACT FROM AUTHOR]