Perfusion Abnormalities Research Articles

Anomaly Detection in Optical Coherence Tomography Angiography (OCTA) with a Vector-Quantized Variational Auto-Encoder (VQ-VAE).

Optical coherence tomography angiography (OCTA) provides detailed information on retinal blood flow and perfusion. Abnormal retinal perfusion indicates possible ocular or systemic disease. We propose a deep learning-based anomaly detection model to identify such anomalies in OCTA. It utilizes two deep learning approaches. First, a representation learning with a Vector-Quantized Variational Auto-Encoder (VQ-VAE) followed by Auto-Regressive (AR) modeling. Second, it exploits epistemic uncertainty estimates from Bayesian U-Net employed to segment the vasculature on OCTA en face images. Evaluation on two large public datasets, DRAC and OCTA-500, demonstrates effective anomaly detection (an AUROC of 0.92 for the DRAC and an AUROC of 0.75 for the OCTA-500) and localization (a mean Dice score of 0.61 for the DRAC) on this challenging task. To our knowledge, this is the first work that addresses anomaly detection in OCTA.

Perfusion MRI in Cerebral Venous and Sinus Thrombosis.

Cerebral venous and sinus thrombosis (CVST) leads to perfusion abnormality in the brain. Our aim was to assess perfusion abnormalities in the center and periphery of the parenchymal lesion in CVST patients and correlate with the clinical outcome. Dynamic susceptibility contrast (DSC) perfusion imaging was performed in patients with CVST. Relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and mean transit time (MTT) values were obtained in the center and periphery of the parenchymal lesion. A total of 30 consecutive patients of CVST were included in the study. Parenchymal lesion was present in 21 (70%) patients. In rest 9, perfusion map was showing some abnormality although conventional MRI was normal. Mean rCBV and MTT were increasing from periphery of the lesion to the center (rCBV 69.93 ± 29.79 at periphery (PL2) to 92.49 ± 32.07 at center of the lesion and 69.19 ± 25.52 at normal appearing contralateral brain parenchyma (NABP). MTT 11.83 ± 3.76 at periphery (PL2) to 15.27 ± 5.49 at center of the lesion and 10.63 ± 3.37 at NABP). rCBV and MTT from abnormal perfusion areas from 9 patients without parenchymal abnormalities are 92.89 ± 17.76 and 15.92 ± 3.66 respectively. There is an increasing trend of MTT and rCBV from periphery to center of the parenchymal lesion. MTT is the most consistent parameter to be abnormal in patients of CVST even in patients without parenchymal lesion. Residual neurological deficit was found in patients with increased rCBV and having large hemorrhagic infarct.

Pulmonary perfusion in long-term survivors of COVID-19-related severe acute respiratory distress syndrome treated by extracorporeal membrane oxygenation.

COVID-19associates with a hypercoagulant state and an increased risk for venous thromboembolic events (VTEs). Whether severe COVID-19 infection requiringextracorporeal membrane oxygenation(ECMO) support might lead to chronic pulmonary perfusion abnormalities and chronic thromboembolic pulmonary disease/hypertension remains unclear. The purpose of this study was to evaluate chronic pulmonary perfusion abnormalities in long-term survivors of COVID-19-related severe acute respiratory distress syndrome (ARDS) treated by ECMOat our institution. Pulmonary perfusion was examined by ventilation/perfusion(V/Q) single-photon emission computed tomographyor V/Q planar scintigraphy at least 3 months after ECMO explantation, comorbidities and incidence of thromboembolic events were recorded as well. Of 172 COVID-19 patients treated by ECMO for severe COVID-19 pneumonia between March 2020 and November 2021, only 80 were successfully weaned from ECMO. Of those, 37 patients were enrolled into the present analysis (27% female, mean age 52 years). Median duration of ECMO support was 12 days. In 24 (65%) patients VTE was recorded in the acute phase (23 patients developed ECMO cannula-related deep vein thrombosis, 5 of them had also a pulmonary embolism, and one thrombus was associated with a central catheter). The median duration between ECMO explantation and assessment of pulmonary perfusion was 420 days. No segmental or larger mismatched perfusion defects were then detected in any patient. In conclusion, in long-term survivors of COVID-19-related ARDS treated by ECMO, no persistent pulmonary perfusion abnormalities were detected although VTE was common.

Cesarean Scar Ectopic Pregnancy: A Do-Not-Miss Diagnosis.

The rate of cesarean section (CS) for delivery has increased internationally, reaching 50% in some countries. Abnormal implantation of a new pregnancy at the site of the prior hysterotomy is an important complication because of the risks of hemorrhage, uterine rupture, and progression to placenta accreta spectrum (PAS), a condition with high morbidity with potential for catastrophic obstetric hemorrhage, maternal and fetal mortality, and loss of fertility. Cesarean scar ectopic pregnancy (CSEP) is the recommended term to describe these pregnancies, which are recognized on the basis of the sac implantation site, growth pattern, and associated abnormal perfusion. The true incidence of CSEP is unknown because the condition is likely underdiagnosed and underreported. The 2022 Society for Maternal-Fetal Medicine consult series notes that severe maternal morbidity and mortality are linked to difficulty in making the diagnosis of CSEP. The authors review the signs of CSEP at imaging, some pitfalls that may lead to delayed or missed diagnosis, and the consequences thereof. CSEPs must be differentiated from low implantation of a normal pregnancy, cervical ectopic pregnancy, and evolving pregnancy loss. Early recognition allows prompt and safe treatment that is usually surgical. Early treatment results in decreased health care costs, a shorter hospital stay, preservation of fertility, and prevention of iatrogenic preterm delivery, which is typical in cases that progress to PAS. Hysterectomy has serious negative psychologic consequences for patients of childbearing age; early diagnosis and prompt treatment of CSEP can prevent this often-ignored complication. ©RSNA, 2024 Supplemental material is available for this article.

Factors affecting the performance of a novel artificial intelligence-based coronary computed tomography-derived ischemia algorithm against PET perfusion imaging

Abstract Background An artificial intelligence-based quantitative coronary computed tomography angiography (CCTA) algorithm (AI-QCTischemia) employs 38 morphological features from CCTA aiming to identify ischemic coronary artery disease (CAD) defined as invasive FFR≤0.80. Recent studies have demonstrated good diagnostic accuracy and prognostic value of this algorithm. However, discrepancies between AI-QCTischemia and positron emission tomography (PET) myocardial perfusion have been observed. Purpose To detect the potential factors that are associated with discrepant findings between AI-QCTischemia and PET perfusion. Methods 662 patients, who had suspected obstructive CAD on CCTA and underwent [15O]H2O PET perfusion, were analysed. Demographic and imaging data were compared between the groups with concordant and discrepant findings. Multivariable logistic regressions were used to identify factors independently associated with discrepancy. In addition, PET-based relative flow reserve (RFR) was used to measure blood flow heterogeneity per patient. Results 453 (68%) patients had concordant findings by both methods. Out of the 209 (32%) patients with discrepant findings, 62 patients (9% of total) had normal AI-QCTischemia but abnormal PET perfusion ("false negative", FN group). In 147 patients (22% of total), AI-QCTischemia was abnormal despite having normal PET perfusion ("false positive", FP group). The patients in the FN group as compared to patients with true negative findings were more often males, smokers, had less often good CCTA image quality and had more advanced CAD by means of total calcium score, diameter stenosis, and percent atheroma volume (PAV). However, none of these parameters was statistically significant in multivariable analysis. In addition, more homogenous myocardial perfusion by means of RFR was observed in the FN group as compared to true positive findings (median±IQR: 0.68±0.15 vs. 0.56±0.23, p<0.001). In the FN group, 21 (34%) patients had globally decreased perfusion. The patients in the FP group as compared to patients with true positive findings were more often females, older, and had less often typical angina and less advanced CAD. In multivariable analysis, age per 1 year increase (OR, 95% CI: 0.955 (0.923–0.989), p=0.010), typical angina (1.796 (1.015–3.179), p=0.044), diameter stenosis per 1% increase (1.058 (1.036–1.080), p<0.001) and PAV per 1% increase (1.103 (1.051–1.158), p<0.001) were significantly predicting true positive findings. Conclusion Discrepancy between AI-QCTischemia and PET perfusion was found in 32% of patients. Age, typical angina, and features in AI-QCTischemia algorithm, such as diameter stenosis and PAV are associated with normal perfusion in abnormal AI-QCTischemia ("false positive") patients. On the other hand, normal AI-QCTischemia in abnormal PET perfusion ("false negative") patients was associated with higher RFR suggesting microvascular disease, which was found in 34% of these patients.Scatter plot

Lung structural and functional impairments in young children with cystic fibrosis diagnosed following newborn screening – A nationwide observational study

BackgroundNon-invasive and sensitive clinical endpoints are needed to monitor onset and progression of early lung disease in children with cystic fibrosis (CF). We compared lung clearance index (LCI), FEV1, functional and structural lung magnetic resonance imaging (MRI) outcomes in Swiss children with CF diagnosed following newborn screening. MethodsLung function (LCI, FEV1) and unsedated functional and structural lung MRI was performed in 79 clinically stable children with CF (3 – 8 years) and 75 age-matched healthy controls. Clinical information was collected throughout childhood. ResultsLCI, ventilation and perfusion defects, and structural MRI scores were significantly higher in children with CF compared with controls, but FEV1 was not different between groups. Lung MRI outcomes correlated significantly with LCI (morphology score (r = 0.56, p < 0.001); ventilation defects (r = 0.43, p = 0.001); perfusion defects (r = 0.64, p < 0.001), but not with FEV1. Lung MRI outcomes were more sensitive to detect impairments in children with CF (abnormal ventilation and perfusion outcomes in 47 %, morphology score in 30 %) compared with lung function (abnormal LCI in 21 % and FEV1 in 4.8 %). Pulmonary exacerbations, respiratory hospitalizations, and increase in patient-reported cough was associated with higher LCI and higher structural and functional MRI outcomes. ConclusionsThe LCI and lung MRI outcomes non-invasively detect even mild early lung disease in young children with CF diagnosed following newborn screening. Pulmonary exacerbations and early respiratory symptoms were risk factors for structural and functional impairment in childhood.

Liver fibrosis detected by diffusion-weighted magnetic resonance imaging and its functional correlates in Fontan patients.

The evaluation of Fontan-associated liver disease is often challenging. Diffusion-weighted magnetic resonance imaging can detect hepatic fibrosis from capillary perfusion and diffusion abnormalities from extracellular matrix accumulation. This study investigated its role in the evaluation of liver disease in Fontan patients and explored possible diagnostic methods for early detection of advanced liver fibrosis. Stable adult Fontan patients who could safely be examined with magnetic resonance imaging were enrolled, and blood biomarkers, transient elastography were also examined. Forty-six patients received diffusion-weighted imaging; and 58.7% were diagnosed with advanced liver fibrosis (severe liver fibrosis, 37.0%, and cirrhosis 21.7%). Two parameters of hepatic dysfunction, platelet counts (Spearman's ρ: -0.456, P = 0.001) and cholesterol levels (Spearman's ρ: -0.383, P = 0.009), decreased with increasing severity of fibrosis. Using transient elastography, a cut-off value of 14.2 kPa predicted the presence of advanced liver fibrosis, but with a low positive predictive value. When we included platelet count, cholesterol, post-Fontan years and transient elastography values as a composite, the capability of predicting advanced liver fibrosis was the most satisfactory (C statistic 0.817 ± 0.071, P < 0.001). A cut-off value of 5.0 revealed a sensitivity of 78% and a specificity of 82%. In Fontan patients, diffusion-weighted imaging was helpful in detecting liver fibrosis that was correlated with hepatic dysfunction. A simple score was proposed for long-term surveillance and early detection of advanced liver disease in adult Fontan patients. For adult Fontan patients with a calculated score > 5.0, we may consider timely diffusion-weight imaging and early management for liver complications.

Effect of Beta-Blocker Consumption on the Severity and Extension of Perfusion Defects in Dipyridamole Myocardial Perfusion Single-Photon Emission Computed Tomography.

Background Regarding the less-known effects of beta-blocker consumption on the diagnostic value of the myocardial perfusion scan with dipyridamole stress in coronary artery disease (CAD), we aimed to compare the findings of the scans done on the beta-blocker consumption course and after discontinuation of this medications. Materials and Methods Thirty patients with probably CAD and abnormal myocardial perfusion scans (presence of reversible defect), who had been treated with beta-blockers for at least 3 months, were studied. Dipyridamole stress phase of myocardial perfusion single-photon emission computed tomography (SPECT) was performed two times with an interval of about 1 week, once after discontinuation of all antianginal and anti-ischemic medications, statins, and beta-blockers for 72 hours prior to the study, and again after discontinuation of all these medications except for beta-blockers. Imaging was done with the same protocol, radiopharmaceutical dose, and imaging parameters. Summed stress score (SSS), summed stress rest, and summed difference scores (SDS), total perfusion deficit (TPD), severity, and extension of myocardial perfusion defects in three coronary artery territories were analyzed, using quantitative perfusion SPECT software. Results Most variables such as SSS, SDS, TPD, severity, and extension of defects showed a significant difference between the two conditions including beta-blocker consumption and after discontinuing beta-blocker consumption before stress imaging ( p < 0.05). Moreover, in patients on treatment with metoprolol, all studied factors including SSS, SDS, TPD, severity, and extension of perfusion defects were significantly reduced when patients consumed beta-blockers before SPECT evaluation ( p < 0.05). Conclusion Beta-blocker consumption can lead to a decrease in the severity and extent of myocardial perfusion defects and therefore probably a decrease in the sensitivity of myocardial scans. Discontinuation of beta-blocker prior to the dipyridamole myocardial perfusion scan can improve diagnostic accuracy.

Assessment of Perfusion Abnormalities in a Case of Autism Spectrum Disorders Using 99mTc ECD Brain SPECT: A Landmark case in Bangladesh

The prevalence of Autism Spectrum Disorders (ASD) has witnessed a rapid increase globally, necessitating effective diagnostic tools for comprehensive assessment. This case report presents a three-year-old male child clinically identified with ASD, undergoing a brain perfusion scan using single-photon emission computed tomography (SPECT). Hypoperfusion, characterized by multiple focal areas of decreased radiotracer concentration, was observed in frontal lobes, left temporal lobe, right parietal, right precuneus, and both hypothalami. The application of the e-ZIS system indicated a severity of rCBF decrease in specific voxels. This case underscores the utility of radionuclide brain SPECT imaging in unveiling abnormal rCBF patterns in ASD patients. Establishing a correlation between these abnormalities and symptom profiles could enhance treatment strategies, incorporating innovative interventions and specific medications tailored to the observed abnormalities.

Diagnostic Accuracy of SPECT for Mild Traumatic Brain Injury: A Systematic Review and Meta-analysis.

This study examines the diagnostic accuracy of brain perfusion SPECT for mild traumatic brain injury (mTBI). A systematic review and meta-analysis was performed according to PRISMA guidelines (PROSPERO: CRD42023484636). Five databases were searched for studies evaluating brain perfusion SPECT in adult patients with mTBI (GCS 13-15). Study quality was assessed using a modified QUADAS-2 tool. A meta-analysis was performed to pool proportions of hypoperfusion abnormalities across brain lobes. Of 4735 records, 22 studies (5 longitudinal [40% high quality], 17 cross-sectional [24% high quality]) were included totaling 800 patients (mean age, 37.4 ± 12.6 years; 36.4% female). Meta-analysis of proportions indicated that the frontal lobe most frequently showed hypoperfusion on brain perfusion SPECT (pooled proportion 40.1% [95% confidence interval, 31.2% to 49.8%], 99/254, I2 = 54.5%), followed by the temporal lobe (26.1% [95% confidence interval, 19.9% to 33.6%], 68/254, I2 = 30.7%). Several studies found that hypoperfusion abnormalities were associated with neuropsychological findings. Also, brain perfusion SPECT could detect abnormalities not seen on MRI. Abnormalities in perfusion on brain perfusion SPECT may be more readily detected with a quantitative assessment compared with a visual assessment alone, although there appears to be no consensus on the optimal method for image interpretation. Evidence evaluating the sensitivity and specificity of brain perfusion SPECT for mTBI was limited. Using the GRADE framework, the evidence was rated as low. Although perfusion abnormalities can be seen in patients with mTBI, commonly in the frontal and temporal lobes, the findings are nonspecific and may derive from various factors. Ultimately, brain perfusion SPECT provides additional information for mTBI, but the final added value for the detection of mTBI is unknown.

1519-P: Endothelial Injury Predicts Carbohydrate Metabolism Trajectories after COVID-19

Introduction &amp; Objective: Diabetes and SARS-CoV-2 infection target the endothelium causing perfusion abnormalities. We hypothesized that COVID-19 impairs insulin action and/or insulin secretion, and that systemic endothelial injury (EI) slows post-hospitalization recovery of these parameters. Methods: 20 hospitalized adults with COVID-19 and acute hypoxemia (8 with DM) were tested for markers of endothelial function (hospital discharge, 1, 3 months) and oral glucose tolerance tests (OGTT) (1 and 3 months). Insulin sensitivity and insulin &amp; C-peptide secretion metrics were assessed with empirical models (HOMA β, HOMA-IR) and mathematical ordinary differential equation (ODE) based models [(ISS (Sigma, SI), CSR (CSR0 (fasting), CSR-km (non-fasting)), ISR (ISR-km (non-fasting)), and ultradian ULS (a1, Rg)]. Results: Table 1 indicates significant correlations between patient-specific changes normalized over time (slopes) in EI and endocrine metrics. Uncertainty was estimated with linear mixed models adjusted for diabetes status and sex, respectively for each metric. Individually paired marker and metric slopes characterizing changes in participant physiological states were associated using linear regression models. Significance of predictive impact was interpreted from associated p-values of each slope pairing. Conclusion: Changes in EI predict post-hospital recovery of carbohydrate metabolism. Disclosure J.E.B. Reusch: Advisory Panel; Medtronic. D. Albers: None. Y. Wang: None. J. Briggs: None. R. Maicki: None. J. Stroh: None. A. Gupta: None. A. Garcia: None. V. Singh: None. T.D. Hiller: None. A. Sherman: None. N. Rasouli: Advisory Panel; Eli Lilly and Company, Novo Nordisk. Research Support; Novo Nordisk. I.S. Douglas: None. Funding R01 DK130351

The relation of lactate level and carbon dioxide pressure discrepancies between transcutaneous and arterial measurements.

Partial carbondioxide pressure of the arterial blood (PaCO2) is used to evaluate alveolar ventilation. Transcutaneous carbon dioxide pressure (TcCO2) monitoring has been developed as a non-invasive (NIV) alternative to arterial blood gas analysis (ABG). Studies have shown that decreased tissue perfusion leads to increased carbondioxide (CO2). The use of transcutaneous capnometry may be unreliable in patients with perfusion abnormalities. In this study, we aimed to evaluate the relation between TcCO2-PaCO2 and lactate level which is recognized as a marker of hypoperfusion. In this prospective cohort study in critical care patients with hypercapnic respiratory failure (PaCO2 ≥45 mmHg) who received NIV between April 2019 and January 2020 in the intensive care unit were enrolled in the study. Patients' simultaneously measured TcCO2 and PaCO2 values of hypercapnic patients were recorded. Each paired measurement was categorized into two groups; normal lactate (<2 mmol/L) and increased lactate (≥2 mmol/L). A total of 116 paired TcCO2 and PaCO2 measurements of 29 patients were recorded. Bland-Altman analysis showed the mean bias between the TcCO2 and PaCO2 and 95% limits of agreement (LOA) in all measurements (1.75 mmHg 95% LOA -3.67 to 7.17); in the normal lactate group (0.66 mmHg 95% LOA -1.71 to 3.03); and in the increased lactate group (5.17 mmHg 95% LOA -1.63 to 11.97). The analysis showed a correlation between lactate level and the difference between TcCO2 and PaCO2 (r= 0.79, p< 0.001) and a negative correlation between mean blood pressure and the difference between TcCO2 and PaCO2 (r= -0.54, p= 0.001). Multiple regression analysis results showed that lactate level was independently associated with increased differences between TcCO2 and PaCO2 (Beta= 0.875, p< 0.001). TcCO2 monitoring may not be reliable in patients with increased lactate levels. TcCO2 levels should be checked by ABG analysis in these patients.

Unique model of chronic hypoxia in fetal lambs demonstrates abnormal contrast-enhanced ultrasound brain perfusion

BackgroundChildren with congenital heart disease (CHD) demonstrate long-term neurodevelopmental impairments. We investigated contrast-enhanced ultrasound (CEUS) cerebral perfusion in a fetal animal model exposed to sub-physiologic oxygen at equivalent levels observed in human fetuses with CHD.MethodsFifteen fetal lambs [hypoxic animals (n = 9) and normoxic controls (n = 6)] maintained in an extrauterine environment underwent periodic brain CEUS. Perfusion parameters including microvascular flow velocity (MFV), transit time, and microvascular blood flow (MBF) were extrapolated from a standardized plane; regions of interest (ROI) included whole brain, central/thalami, and peripheral parenchymal analyses. Daily echocardiographic parameters and middle cerebral artery (MCA) pulsatility indices (PIs) were obtained.ResultsHypoxic lambs demonstrated decreased MFV, increased transit time, and decreased MBF (p = 0.026, p = 0.016, and p < 0.001, respectively) by whole brain analyses. MFV and transit time were relatively preserved in the central/thalami (p = 0.11, p = 0.08, p = 0.012, respectively) with differences in the peripheral parenchyma (all p < 0.001). In general, cardiac variables did not correlate with cerebral CEUS perfusion parameters. Hypoxic animals demonstrated decreased MCA PI compared to controls (0.65 vs. 0.78, respectively; p = 0.027).ConclusionAberrations in CEUS perfusion parameters suggest that in environments of prolonged hypoxia, there are regional microvascular differences incompletely characterized by MCA interrogation offering insights into fetal conditions which may contribute to patient outcomes.ImpactThis work utilizes CEUS to study cerebral microvascular perfusion in a unique fetal animal model subjected to chronic hypoxic conditions equal to fetuses with congenital heart disease. CEUS demonstrates altered parameters with regional differences that are incompletely characterized by MCA Doppler values.These findings show that routine MCA Doppler interrogation may be inadequate in assessing microvascular perfusion differences.To our knowledge, this study is the first to utilize CEUS to assess microvascular perfusion in this model.The results offer insight into underlying conditions and physiological changes which may contribute to known neurodevelopmental impairments in those with congenital heart disease.

A case of pseudo-Kaposi sarcoma with chronic limb-threatening ischemia

BackgroundPseudo-Kaposi sarcoma (PKS) is a rare vascular proliferative disease, caused by arteriovenous malformation (AVM) and chronic venous insufficiency. The lesions are characterized by purple or reddish-brownish papules, plaques, and nodules. Although benign, it is clinically similar to Kaposi's sarcoma (KS), a malignant disease, and must be differentiated by histopathological examination. We report a rare case of PKS with chronic limb-threatening ischemia (CLTI).Case presentationAn 83-year-old man with diabetes mellitus (DM) presented to a local dermatology department with a complaint of a right second toe ulcer and was, thereby, referred to our department due to arterial bleeding during skin biopsy to exclude malignant diseases. Although the pulsation of dorsalis pedis artery of the affected limb was palpable, the skin perfusion pressure was only 20 and 30 mmHg on the dorsum and planter surface, respectively, indicating severe ischemia of toe and forefoot. Ultrasonography and computed tomography revealed an AVM around the right second metatarsophalangeal joint and occlusion of the right dorsalis pedis artery in the middle, indicating CLTI in the background. Pathological findings of the skin biopsy found capillary blood vessel proliferation, hemosiderin deposition, and extravascular red blood cell leakage in the dermal layer, which could be found in KS. However, CD34 was normally stained in the vascular endothelium, and human herpesvirus-8 staining was negative, resulting in the pathological diagnosis of PKS, a proliferative vascular lesion associated with AVM. The ulcer was spontaneously epithelialized, but 2 years later the ulcer recurred and infection developed, necessitating treatment for abnormal blood flow. Transarterial embolization using N-butyl 2-cyanoacrylate for the AVM controlled abnormal perfusion once; however, the procedure exacerbated perfusion of the toe, resulting in foot ulcer progression. Forefoot amputation with surgical excision of AVM was performed, and thereby, wound healing was achieved.ConclusionThis is a rare case of PKS with CLTI complicated with AVM. As there is currently no established consensus on the treatment of PKS, the approach to treatment strategy should be tailored to the specific condition of each patient.

Contrast agent-free functional magnetic resonance imaging with matrix pencil decomposition to quantify abnormalities in lung perfusion and ventilation in patients with cystic fibrosis.

Previous studies showed that contrast-enhanced (CE) morpho-functional magnetic resonance imaging (MRI) detects abnormalities in lung morphology and perfusion in patients with cystic fibrosis (CF). Novel matrix pencil decomposition MRI (MP-MRI) enables quantification of lung perfusion and ventilation without intravenous contrast agent administration. To compare MP-MRI with established morpho-functional MRI and spirometry in patients with CF. Thirty-nine clinically stable patients with CF (mean age 21.6 ± 10.7 years, range 8-45 years) prospectively underwent morpho-functional MRI including CE perfusion MRI, MP-MRI and spirometry. Two blinded chest radiologists assessed morpho-functional MRI and MP-MRI employing the validated chest MRI score. In addition, MP-MRI data were processed by automated software calculating perfusion defect percentage (QDP) and ventilation defect percentage (VDP). MP perfusion score and QDP correlated strongly with the CE perfusion score (both r = 0.81; p < 0.01). MP ventilation score and VDP showed strong inverse correlations with percent predicted FEV1 (r = -0.75 and r = -0.83; p < 0.01). The comparison of visual and automated parameters showed that both MP perfusion score and QDP, and MP ventilation score and VDP were strongly correlated (r = 0.74 and r = 0.78; both p < 0.01). Further, the MP perfusion score and MP ventilation score, as well as QDP and VDP were strongly correlated (r = 0.88 and r = 0.86; both p < 0.01). MP-MRI detects abnormalities in lung perfusion and ventilation in patients with CF without intravenous or inhaled contrast agent application, and correlates strongly with the well-established CE perfusion MRI score and spirometry. Automated analysis of MP-MRI may serve as quantitative noninvasive outcome measure for diagnostic monitoring and clinical trials.

Prognostic Value of Stress Perfusion Cardiac MRI in Cardiovascular Disease: A Systematic Review and Meta-Analysis of the Effects of the Scanner, Stress Agent, and Analysis Technique.

Purpose To perform a systematic review and meta-analysis to assess the prognostic value of stress perfusion cardiac MRI in predicting cardiovascular outcomes. Materials and Methods A systematic literature search from the inception of PubMed, Embase, Web of Science, and China National Knowledge Infrastructure until January 2023 was performed for articles that reported the prognosis of stress perfusion cardiac MRI in predicting cardiovascular outcomes. The quality of included studies was assessed using the Quality in Prognosis Studies tool. Reported hazard ratios (HRs) of univariable regression analyses with 95% CIs were pooled. Comparisons were performed across different analysis techniques (qualitative, semiquantitative, and fully quantitative), magnetic field strengths (1.5 T vs 3 T), and stress agents (dobutamine, adenosine, and dipyridamole). Results Thirty-eight studies with 58 774 patients with a mean follow-up time of 53 months were included. There were 1.9 all-cause deaths and 3.5 major adverse cardiovascular events (MACE) per 100 patient-years. Stress-inducible ischemia was associated with a higher risk of all-cause mortality (HR: 2.55 [95% CI: 1.89, 3.43]) and MACE (HR: 3.90 [95% CI: 2.69, 5.66]). For MACE, pooled HRs of qualitative, semiquantitative, and fully quantitative methods were 4.56 (95% CI: 2.88, 7.22), 3.22 (95% CI: 1.60, 6.48), and 1.78 (95% CI: 1.39, 2.28), respectively. For all-cause mortality, there was no evidence of a difference between qualitative and fully quantitative methods (P = .79). Abnormal stress perfusion cardiac MRI findings remained prognostic when subgrouped based on underlying disease, stress agent, and field strength, with HRs of 3.54, 2.20, and 3.38, respectively, for all-cause mortality and 3.98, 3.56, and 4.21, respectively, for MACE. There was no evidence of subgroup differences in prognosis between field strengths or stress agents. There was significant heterogeneity in effect size for MACE outcomes in the subgroups assessing qualitative versus quantitative stress perfusion analysis, underlying disease, and field strength. Conclusion Stress perfusion cardiac MRI is valuable for predicting cardiovascular outcomes, regardless of the analysis method, stress agent, or magnetic field strength used. Keywords: MR-Perfusion, MRI, Cardiac, Meta-Analysis, Stress Perfusion, Cardiac MR, Cardiovascular Disease, Prognosis, Quantitative © RSNA, 2024 Supplemental material is available for this article.

Abnormal Cerebrovascular Activity, Perfusion, and Glymphatic Clearance in Lewy Body Diseases.

Cerebrovascular activity is not only crucial to optimal cerebral perfusion, but also plays an important role in the glymphatic clearance of interstitial waste, including α-synuclein. This highlights a need to evaluate how cerebrovascular activity is altered in Lewy body diseases. This review begins by discussing how vascular risk factors and cardiovascular autonomic dysfunction may serve as upstream or direct influences on cerebrovascular activity. We then discuss how patients with Lewy body disease exhibit reduced and delayed cerebrovascular activity, hypoperfusion, and reductions in measures used to capture cerebrospinal fluid flow, suggestive of a reduced capacity for glymphatic clearance. Given the lack of an existing framework, we propose a model by which these processes may foster α-synuclein aggregation and neuroinflammation. Importantly, this review highlights several avenues for future research that may lead to treatments early in the disease course, prior to neurodegeneration. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Tenecteplase versus standard of care for minor ischaemic stroke with proven occlusion (TEMPO-2): a randomised, open label, phase 3 superiority trial

Tenecteplase versus standard of care for minor ischaemic stroke with proven occlusion (TEMPO-2): a randomised, open label, phase 3 superiority trial

The additive prognostic value of end-systolic pressure-volume relation by stress CMR in patients with known or suspected coronary artery disease.

The difference between rest and peak stress end-systolic pressure-volume relation (ΔESPVR) is an afterload-independent index of left ventricular (LV) contractility. We assessed the independent prognostic value of ΔESPVR index by dipyridamole stress-cardiovascular magnetic resonance (CMR) in patients with known/suspected coronary artery disease (CAD). We considered 196 consecutive patients (62.74 ± 10.66years, 49 females). Wall motion and perfusion abnormalities at rest and peak stress were analysed. Replacement myocardial fibrosis was detected by late gadolinium enhancement(LGE) technique. The ESPVR was evaluated at rest and peak stress from raw measurement of systolic arterial pressure and end-systolic volume by biplane Simpson's method. A reduced ΔESPVR index (≤ 0.02mmHg/mL/m2) was found in 88(44.9%) patients and it was associated with a lower LV ejection fraction(EF) and with a higher frequency of abnormal stress CMR and myocardial fibrosis. During a mean follow-up of 53.17 ± 28.21months, 50(25.5%) cardiac events were recorded: 5 cardiac deaths, 17 revascularizations, one myocardial infarction, 23 hospitalisations for heart failure or unstable angina, and 4 ventricular arrhythmias. According to Cox regression analysis, diabetes, family history, LVEF, abnormal stress CMR, myocardial fibrosis, and reduced ΔESPVR were significant univariate prognosticators. In the multivariate analysis the independent predictors were ΔESPVR index ≤ 0.02mmHg/mL/m2 (hazard ratio-HR = 2.58, P = 0.007), myocardial fibrosis (HR = 2.13, P = 0.036), and diabetes (HR = 2.33, P = 0.012). ΔESPVR index by stress-CMR was independently associated with cardiac outcomes in patients with known/suspected CAD, in addition to replacement myocardial fibrosis and diabetes. Thus, the assessment of ΔESPVR index may be included into the standard stress-CMR exam to further stratify the patients.

Prognostic value of a novel artificial intelligence-based coronary CTA-derived ischemia algorithm among patients with normal or abnormal myocardial perfusion

BackgroundAmong patients with obstructive coronary artery disease (CAD) on coronary computed tomography angiography (CTA), downstream positron emission tomography (PET) perfusion imaging can be performed to assess the presence of myocardial ischemia. A novel artificial-intelligence-guided quantitative computed tomography ischemia algorithm (AI-QCTischemia) aims to predict ischemia directly from coronary CTA images. We aimed to study the prognostic value of AI-QCTischemia among patients with obstructive CAD on coronary CTA and normal or abnormal downstream PET perfusion. MethodsAI-QCTischemia was calculated by blinded analysts among patients from the retrospective coronary CTA cohort at Turku University Hospital, Finland, with obstructive CAD on initial visual reading (diameter stenosis ≥50%) being referred for downstream 15O-H2O-PET adenosine stress perfusion imaging. All coronary arteries with their side branches were assessed by AI-QCTischemia. Absolute stress myocardial blood flow ≤2.3 ​ml/g/min in ≥2 adjacent segments was considered abnormal. The primary endpoint was death, myocardial infarction, or unstable angina pectoris. The median follow-up was 6.2 [IQR 4.4–8.3] years. Results662 of 768 (86%) patients had conclusive AI-QCTischemia result. In patients with normal 15O-H2O-PET perfusion, an abnormal AI-QCTischemia result (n ​= ​147/331) vs. normal AI-QCTischemia result (n ​= ​184/331) was associated with a significantly higher crude and adjusted rates of the primary endpoint (adjusted HR 2.47, 95% CI 1.17–5.21, p ​= ​0.018). This did not pertain to patients with abnormal 15O-H2O-PET perfusion (abnormal AI-QCTischemia result (n ​= ​269/331) vs. normal AI-QCTischemia result (n ​= ​62/331); adjusted HR 1.09, 95% CI 0.58–2.02, p ​= ​0.794) (p-interaction ​= ​0.039). ConclusionAmong patients with obstructive CAD on coronary CTA referred for downstream 15O-H2O-PET perfusion imaging, AI-QCTischemia showed incremental prognostic value among patients with preserved perfusion by 15O-H2O-PET imaging, but not among those with reduced perfusion.