Perfusion Abnormalities Research Articles

Diagnostic Value of Magnetocardiography to Detect Abnormal Myocardial Perfusion: A Pilot Study.

Magnetocardiography (MCG) is a novel non-invasive technique that detects subtle magnetic fields generated by cardiomyocyte electrical activity, offering sensitive detection of myocardial ischemia. This study aimed to assess the ability of MCG to predict impaired myocardial perfusion using single-photon emission computed tomography (SPECT). A total of 112 patients with chest pain underwent SPECT and MCG scans, from which 65 MCG output parameters were analyzed. Using least absolute shrinkage and selection operator (LASSO) regression to screen for significant MCG variables, three machine learning models were established to detect impaired myocardial perfusion: random forest (RF), decision tree (DT), and support vector machine (SVM). The diagnostic performance was evaluated based on the sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC). Five variables, the ratio of magnetic field amplitude at R-peak and positive T-peak (RoART+), R and T-peak magnetic field angle (RTA), maximum magnetic field angle (MAmax), maximum change in current angle (CCAmax), and change positive pole point area between the T-wave beginning and peak (CPPPATbp), were selected from 65 automatic output parameters. RTA emerged as the most critical variable in the RF, DT, and SVM models. All three models exhibited excellent diagnostic performance, with AUCs of 0.796, 0.780, and 0.804, respectively. While all models showed high sensitivity (RF = 0.870, DT = 0.826, SVM = 0.913), their specificity was comparatively lower (RF = 0.500, DT = 0.300, SVM = 0.100). Machine learning models utilizing five key MCG variables successfully predicted impaired myocardial perfusion, as confirmed by SPECT. These findings underscore the potential of MCG as a promising future screening tool for detecting impaired myocardial perfusion. ChiCTR2200066942, https://www.chictr.org.cn/showproj.html?proj=187904.

Utility of automated CT perfusion software in acute ischemic stroke with large and medium vessel occlusion.

Early diagnosis of large vessel occlusion (LVO) in acute stroke often requires CT angiography (CTA). Automated CT perfusion (CTP) software, which identifies blood flow abnormalities, enhances LVO diagnosis and patient selection for endovascular thrombectomy (EVT). This study evaluates the sensitivity of automated CTP images in detecting perfusion abnormalities in patients with acute ischemic stroke (AIS) and LVO or medium vessel occlusion (MeVO), compared to CTA. We screened acute ischemic stroke patients presenting within 24 h who underwent CT, CTA, and CTP as per institutional protocol. RAPID AI software processed CTP images, while neuroradiologists reviewed CTA for intracranial arterial occlusions. Sensitivity, specificity, and accuracy of automated CTP maps in detecting occlusions were assessed. Of 790 screened patients, 31 were excluded due to lack of RAPID CTP data or poor-quality scans, leaving 759 for analysis. The median age was 71 years (IQR: 61-81), with 47% female. Among them, 678 had AIS, and 81 had AIS ruled out. CTA identified arterial occlusion in 562 patients (74%), with corresponding CTP abnormalities in 537 patients (Tmax > 6 sec). In the 197 without occlusion, CTP was negative in 161. Automated CTP maps had a sensitivity of 95.55% (CI 95: 93.50-97.10%), specificity of 81.73% (CI 95: 75.61-86.86%), negative predictive value of 98.22% (CI 95: 97.39-98.79%), positive predictive value of 63.54% (CI 95: 56.46-70.09%), and overall accuracy of 85.18% (CI 95: 82.45-87.64%). Automated CTP maps demonstrated high sensitivity and negative predictive value for LVOs and MeVOs, suggesting their usefulness as a rapid diagnostic tool, especially in settings without expert neuroradiologists.

The application of mass defect percentage in the evaluation of acute coronary syndrome.

White blood cells, neutrophils, lymphocytes, and neutrophil-to-lymphocyte ratio (NLR) distribution patterns in patients with anatomic coronary disease have previously been associated with cardiac events such as myocardial infarct size, complications, and prognosis. However, it remains unknown whether myocardial perfusion mass defect percentage (MDP) obtained from gated myocardial perfusion imaging (G-MPI) correlates with these hematological parameters. Therefore, our research aimed to investigate the application of MDP in the evaluation of acute coronary syndrome (ACS). Thirty-six patients with ACS underwent single-photon emission computed tomography/computed tomography using retrospective electrocardiography gating during the resting state. The primary outcome was the percentage of left ventricular mass with abnormal myocardial perfusion (i.e. MDP) in G-MPI. Furthermore, the correlation between myocardial perfusion MDP and lymphocyte count, neutrophil count, white blood cell count, and NLR was calculated. In addition, we explored the relationship of myocardial perfusion MDP with other cardiac function parameters obtained from G-MPI, such as summed rest score, left ventricular ejection fraction, end-systolic volume, and end-diastolic volume. Myocardial perfusion MDP significantly correlated with white blood cell count, neutrophil count, and NLR ( P < 0.01). Furthermore, these hematological parameters were significantly different between low and high MDP groups. Additionally, myocardial perfusion MDP negatively correlated with end-systolic volume ( r = -0.615) and left ventricular ejection fraction ( r = -0.657). Myocardial perfusion MDP has a high correlation with inflammatory cell counts and cardiac function parameters obtained from G-MPI in ACS; this may be of help in the evaluation and treatment of these patients.

Factors affecting the performance of a novel artificial intelligence-based coronary computed tomography-derived ischaemia algorithm.

AI-QCTischaemia is an FDA-cleared novel artificial intelligence-guided method that utilizes features from coronary computed tomography angiography (CCTA) to predict myocardial ischaemia. To identify factors associated with discrepancy between AI-QCTischaemia and positron emission tomography (PET) perfusion. Six hundred and sixty-two patients with suspected obstructive coronary artery disease (CAD) on CCTA and undergoing [15O]H2O PET were analysed using AI-QCTischaemia. Multivariable logistic regression identified factors associated with discrepancy. Perfusion homogeneity was measured by relative flow reserve. A total of 209 (32%) patients showed discrepancies: 62 (9%) exhibited normal AI-QCTischaemia but abnormal perfusion (false negative AI-QCTischaemia), whereas 147 (22%) had abnormal AI-QCTischaemia despite normal perfusion (false positive AI-QCTischaemia). False positive AI-QCTischaemia patients (vs. true positive) were more often females, older, with less typical angina, and less advanced CAD. In multivariable analysis, typical angina [OR 95% CI: 1.796 (1.015-3.179), P = 0.044], diameter stenosis per 1% increase [1.058 (1.036-1.080), P < 0.001], and percent atheroma volume per 1% increase [1.103 (1.051-1.158), P < 0.001] significantly predicted true positive, while age was inversely associated [0.955 (0.923-0.989), P = 0.010]. False-negative AI-QCTischaemia patients (vs. true negative) were more often males, smokers, with less good CCTA image quality, and more advanced CAD. However, none was significant in multivariable analysis. Furthermore, false-negative AI-QCTischaemia showed more homogenously reduced perfusion by relative flow reserve compared to true positive (median ± IQR: 0.68 ± 0.15 vs. 0.56 ± 0.23, P < 0.001) and 21 (34%) of false negative showed globally reduced perfusion. For abnormal AI-QCTischaemia, younger age, typical angina, more severe stenosis, and more extensive atherosclerosis predicted abnormal PET perfusion. With false negative AI-QCTischaemia, perfusion abnormalities were partly explained by microvascular disease.

Myocardial Perfusion Scintigraphy in Diagnosic of Coronary Heart Disease

&amp;lt;i&amp;gt;Introduction: &amp;lt;/i&amp;gt;Atherosclerosis plays a key role in the etiopathogenesis of cardiovascular diseases. Atherosclerosis is a generalized chronic inflammatory disease of the vascular wall, which results in anatomical and histological changes that, together with functional changes, lead to endothelial dysfunction, narrowing of the arterial lumen, and insufficient blood supply to the tissues. The shift in the incidence of cardiovascular diseases to younger age groups is alarming. The presence of microvascular changes in the myocardium is significant. The high incidence of cardiovascular diseases, especially ischemic heart disease, requires early diagnosis and modern treatment. &amp;lt;i&amp;gt;Aim: &amp;lt;/i&amp;gt;The aim of the paper is to analyse and point out early diagnosis of coronary heart disease using nuclear medicine methods. &amp;lt;i&amp;gt;Set of examined patients and methodology: &amp;lt;/i&amp;gt;Using nuclear medicine methods, we try to detect these changes in time and thus prevent the occurrence of acute coronary events. In nuclear cardiology, instead of a large-area scintillation detector, a new type of cardio-gamma camera &amp;quot;Discovery CZT 530c&amp;quot; based on the principle of semiconductor detectors began to be used. The abbreviation CZT stands for semiconductor composition (Cadmium-Zinc-Tellur). The set of respondents consisted of 4270 people examined in the years 2014-2016 by myocardial perfusion scintigraphy. There were 950 diabetic patients in the analysed group of the 4270 examined. &amp;lt;i&amp;gt;Results:&amp;lt;/i&amp;gt; In the analysed group of 4270 respondents, 61% had negative findings and 39% had positive findings in terms of the presence of ischemic heart disease. In the group of diabetic patients, there was a negative finding in 28% of respondents and a positive finding in 72% of the respondents in the sense of positive ischemic heart disease. Using myocardial perfusion scintigraphy in the diagnosis of functional changes, we confirmed a great benefit in detecting early changes in coronary heart disease, including in the diagnosis of microvascular angina. &amp;lt;i&amp;gt;Conclusion:&amp;lt;/i&amp;gt; Nuclear medicine methods are of great benefit for the diagnosis of small vessel disease, diabetic cardiomyopathy and cardiac autonomic neuropathy in patients with diabetes mellitus. The new type of cardio gamma camera &amp;quot;Discovery CZT 530c&amp;quot; allows more accurate assessment of myocardial perfusion abnormalities and at the same time the reduction of the radiopharmaceutical dose reduces the patient&amp;apos;s radiation load by 50%.

Comparative study of myocardial perfusion and coronary flow velocity reserve derived from adenosine triphosphate stress myocardial contrast echocardiography in coronary lesions with no/mild stenosis.

Qualitative myocardial perfusion (QMP) derived from myocardial contrast echocardiography reflects the capillary flow, while coronary flow velocity reserve from Doppler spectrum (D-CFVR) of the left anterior descending coronary artery (LAD) is used to assess coronary microvascular function, particularly after excluding severe epicardial coronary stenosis. The present study aimed to assess the relationship of QMP and D-CFVR in detecting coronary microvascular disease (CMVD) by using adenosine triphosphate stress myocardial contrast echocardiography (ATP stress MCE). Seventy-two patients (mean age: 54.22 ± 12.78 years) with chest pain and <50% coronary stenosis diagnosed by quantitative coronary angiography or dual-source CT underwent ATP stress MCE. The distribution of myocardial perfusion and CFVR value was estimated by experienced physicians. Of the 72 LAD with 0%-50% diameter stenosis, 15 (21%) exhibited abnormal CFVR and 31 (43%) displayed abnormal perfusion with ATP stress MCE. Eleven of the 15 LAD territories (73%) with abnormal CFVR values showed abnormal perfusion. However, CFVR was considered normal in 20 LAD territories (35%), despite the presence of perfusion defect in the territory. Abnormal myocardial perfusion during ATP stress MCE was found in a sizable percentage of patients in whom CFVR of the supplying vessel was considered normal.

Diagnostic utility of coronary artery calcium score percentiles and categories to exclude abnormal scans and relevant ischemia in rubidium positron emission tomography.

Despite clinical suspicion, most non-invasive ischemia tests for coronary artery disease (CAD) reveal unremarkable results. Patients with a coronary artery calcium score (CACS) of zero rarely have an abnormal positron emission tomography (PET) and could be deferred from further testing. However, most patients have some extent of coronary calcification. CACS percentiles could be useful to exclude abnormal perfusion in patients with CACS >0, but data from patients with 82Rb PET are lacking. The aim of this study was to assess the diagnostic utility of CACS percentiles in comparison to zero calcium and absolute CACS classes. Consecutive patients with suspected CAD (n = 1,792) referred for 82Rb PET were included and analyzed for abnormal PET (SSS ≥4) and relevant ischemia (>10% myocardium). Test characteristics were calculated. The mean age was 65 ± 11 years, 43% were female, and typical angina was reported in 21%. Abnormal PET/relevant ischemia (>10%) were observed in 19.8%/9.3%. Overall, the sensitivity/negative predictive value (NPV) of a <25th percentile CACS to rule out abnormal PET and relevant ischemia were 93.0%/95.7% and 98.2%/99.5%, respectively. The sensitivity/NPV of CACS 1-9 to rule out abnormal PET and relevant ischemia were 96.0%/91.8% and 97.6%/97.6%, respectively. Except for patients <50 years old, sensitivity for abnormal PET was >90.9% in all age groups. In patients >50 years, the <25th percentile and CACS 1-9 had good test characteristics to rule out abnormal PET and relevant ischemia (>10%). They could be used to extend the scope of application of CACS 0 by 8%-10% to 32%-34% overall of patients who could be deferred from further testing.

The Current and Novel Imaging Modalities for Ocular Vasculitis in Behcet's Disease: A Review.

Behcet's syndrome is a multisystem inflammatory disorder characterized by a chronic relapsing course and diverse clinical manifestations, prominently affecting young adults along the ancient Silk Road and beyond. The disease pathogenesis involves complex interactions between genetic predisposition, environmental triggers, and dysregulated immune responses, leading to systemic vasculitis and tissue damage. Ocular involvement, a hallmark of Behcet's Disease (BD), significantly impacts morbidity, with uveitis as a common initial presentation that can progress to severe vision-threatening complications like retinal vasculitis and occlusive disease. This review consolidates current knowledge on ocular manifestations in BD, emphasizing the pivotal role of multimodal imaging in diagnostic evaluation and management. Fundus photography serves as a baseline tool for documenting intraocular lesions and monitoring treatment responses. Fluorescein angiography remains the gold standard for detecting acute inflammatory changes and vascular leakage patterns essential for disease staging and prognostication. Recent advancements in imaging, such as ultra-wide field imaging (UWF), indocyanine green angiography (ICGA), Doppler ultrasonography, Optical Coherence Tomography (OCT), OCT angiography (OCTA), adaptive optics (AO), and retinal function imaging (RFI), provide unprecedented insights into microvascular dynamics, structural changes, and functional impairments associated with ocular BD. Integration of these advanced imaging modalities enhances early detection of subclinical disease, facilitates precise localization of inflammatory lesions, guides therapeutic interventions, and monitors treatment efficacy. OCT and OCTA, in particular, offer non-invasive, high-resolution assessments of macular edema, vascular perfusion abnormalities, and choroidal thickness alterations critical for optimizing patient care. In conclusion, multimodal imaging represents the cornerstone in the comprehensive management of ocular manifestations in Behcet's Disease, offering clinicians invaluable tools for accurate diagnosis, treatment planning, and long-term monitoring of disease progression and treatment outcomes.

Dual hyperpolarized [1-13C]pyruvate and [13C]urea magnetic resonance imaging of prostate cancer

Dual hyperpolarized [1-13C]pyruvate and [13C]urea magnetic resonance imaging of prostate cancer

Longitudinal Magnetic Resonance Imaging of Changes in Lung Morphology and Perfusion in Children with Cystic Fibrosis From Infancy through Adolescence.

The progression of lung changes in cystic fibrosis (CF) from infancy through adolescence remains poorly understood due to limited longitudinal imaging data. To assess changes in lung morphology and perfusion in children with CF through the pediatric age range by longitudinal chest magnetic resonance imaging (MRI). 1112 annual chest MRI were performed in 226 patients with CF aged 0-18yr. MRI was assessed using a validated MRI scoring system. The MRI global score continuously increased from 5.5±4.6 at infancy (0yr) to 17.9±8.4 at adolescence (range 12-18yr), and the MRI morphology score from 5.0±3.9 to 12.4±6.0 (P<0.001). Bronchiectasis/wall thickening prevalence increased from 89.1% at infancy to approx. 100% from preschool age (1-5yr), and the subscore increased from 3.1±1.9 at infancy to 6.6±2.1 at adolescence (P<0.001). Mucus plugging prevalence increased from 55.4% at infancy to 83.5% at adolescence, and the subscore increased from 1.2±1.6 to 3.7±2.5 in the same period (P<0.001). Perfusion abnormalities were found in 44.4% at infancy, and increased to approx. 90% from preschool age (P<0.001). The MRI perfusion score increased from 1.1±1.6 at infancy to 5.6±3.0 at adolescence (P<0.001). Chronic Pseudomonas aeruginosa infection was associated with higher MRI scores from school age (6-11yr, P<0.05-0.001). This is the first study assessing longitudinal changes in lung morphology and perfusion in CF throughout the pediatric age range, providing percentiles as age-specific reference for lung disease severity. Our data may facilitate the use of MRI as an endpoint in clinical trials in children with CF.

Prognostic value of transient ischemic dilatation by 13N-ammonia PET MPI for short-term outcomes in patients with non-obstructive CAD

ObjectiveTransient ischaemic dilatation (TID) had incremental diagnostic and prognostic value in obstructive coronary artery disease (CAD), but its clinical significance in patients with non-obstructive CAD remains unknown. We aimed to explore the prognostic value of TID in patients with non-obstructive CAD by 13N-ammonia PET imaging.MethodsWe retrospectively studied 131 consecutive patients with non-obstructive CAD undergoing one-day rest-stress 13N-ammonia PET myocardial perfusion imaging (MPI). TID was automatically generated using CardIQ Physio software. The receiver operative characteristic (ROC) curve was used to determine the optimal threshold of TID. The follow-up outcome was major adverse cardiac events (MACE), a composite of re-hospitalization for heart failure or unstable angina, late revascularization, non-fatal myocardial infarction, and cardiac death. Cardiac event-free survivals for normal and abnormal TID were compared using Kaplan–Meier plots and log-rank tests.ResultsDuring a median follow-up of 42.08 ± 17.67 months, 22 (16.7%) patients occurred MACE. The optimal cut-off value of TID was 1.03 based on MACE. Our preliminary outcome analysis suggests that TID-abnormal subjects had a lower overall survival probability. Furthermore, our multivariate analysis reveals abnormal TID was the only independent predictor for MACE in non-obstructive CAD. In the subgroup analysis, an abnormal TID was an independent predictor for MACE in patients with abnormal perfusion patterns.ConclusionAmong patients with non-obstructive CAD, PET-derived TID ≥ 1.03 may identify those with a high risk of subsequent MACE independently. It was also an independent risk factor for poor prognosis in patients with abnormal perfusion.Graphical abstractCAD coronary artery disease, PET positron emission tomography, MPI myocardial perfusion imaging, TID transient ischaemic dilatation, MACE major adverse cardiac events, ROC receiver operative characteristic.

Perfusion Abnormalities on 24-Hour Perfusion Imaging in Patients With Complete Endovascular Reperfusion.

Perfusion abnormalities in the infarct and salvaged penumbra have been proposed as a potential reason for poor clinical outcome (modified Rankin Scale score >2) despite complete angiographic reperfusion (Thrombolysis in Cerebral Infarction [TICI3]). In this study, we aimed to identify different microvascular perfusion patterns and their association with clinical outcomes among TICI3 patients. University Hospital Bern's stroke registry of all patients between February 2015 and December 2021. Macrovascular reperfusion was graded using the TICI scale. Microvascular reperfusion status was evaluated within the infarct area on cerebral blood volume and cerebral blood flow perfusion maps obtained 24-hour postintervention. Primary outcome was functional independence (90-day modified Rankin Scale score 0-2) evaluated with the logistic regression analysis adjusted for age, sex, and 24-hour infarct volume from follow-up imaging. Based on microvascular perfusion findings, the entire cohort (N=248) was stratified into one of the 4 clusters: (1) normoperfusion (no perfusion abnormalities; n=143/248); (2) hyperperfusion (hyperperfusion on both cerebral blood volume and cerebral blood flow; n=54/248); (3) hypoperfusion (hypoperfusion on both cerebral blood volume and cerebral blood flow; n=14/248); and (4) mixed (discrepant findings, eg, cerebral blood volume hypoperfusion and cerebral blood flow hyperperfusion; n=37/248). Compared with the normoperfusion cluster, patients in the hypoperfusion cluster were less likely to achieve functional independence (adjusted odds ratio, 0.3 [95% CI, 0.1-0.9]), while patients in the hyperperfusion cluster tended to have better outcomes (adjusted odds ratio, 3.3 [95% CI, 1.3-8.8]). In around half of TICI3 patients, perfusion abnormalities on the microvascular level can be observed. Microvascular hypoperfusion, despite complete macrovascular reperfusion, is rare but may explain the poor clinical course among some TICI3 patients, while a detrimental effect of hyperperfusion after reperfusion could not be confirmed.

Brain perfusion alterations in patients and survivors of COVID‐19 infection using arterial spin labeling: A systematic review

AbstractCoronavirus disease (COVID‐19) has been shown to impact the central nervous system, leading to various neurological complications. Arterial spin labeling (ASL), a non‐invasive magnetic resonance imaging technique, enables the measurement of cerebral blood flow and perfusion abnormalities. This systematic review aims to synthesize ASL findings in patients with COVID‐19 and assess the potential role of ASL in diagnosing and managing neurological complications. A comprehensive search was conducted on PubMed and Scopus for studies related to ASL in individuals with COVID‐19 or post‐COVID‐19 syndrome published between December 2019 and August 2024. Extracted data encompassed study characteristics, ASL protocols, cognitive assessments, and principal findings. The most consistent observation across studies was hypoperfusion detected in various brain regions, particularly within the frontal lobes, which may correlate with cognitive impairment and olfactory dysfunction. Additionally, some investigations reported hyperperfusion localized to the leptomeninges. These results may reflect underlying mechanisms such as hypoxic–ischemic injury, inflammation, vascular dysfunction, and neuronal damage attributable to COVID‐19. In conclusion, ASL has emerged as a valuable tool for evaluating brain perfusion among patients affected by or recovering from COVID‐19 since it offers critical insights into cerebral hemodynamics and metabolism. Further research is warranted to validate these ASL findings and elucidate whether post‐COVID‐19 syndrome contributes to persistent brain perfusion issues.

Abstract P130: Predictive value of the MCG-based Nomogram model for the anatomical and functional evaluation of coronary artery lesions

Objective: Optical coherence tomography (OCT) is an intravascular imaging technology that can provide cross-sectional images of coronary arteries, which can more accurately assess the condition of coronary artery lesions and the degree of vascular stenosis. It is an important method for the anatomical evaluation of coronary artery lesions. Radionuclide myocardial perfusion imaging (MPI) is a commonly used non-invasive method for functional evaluation of myocardial ischemia in clinical practice. The clinical application of these two methods is greatly limited due to operational risk and high cost. This study aimed to explore the potential predictive value of the MCG-based Nomogram model for the anatomical and functional evaluation of coronary artery lesions. Methods: We reviewed the patients who were hospitalized in the cardiovascular department of our hospital from October 2021 to July 2023 for MCG test. A total of 137 patients were included in the OCT subgroup, including 48 patients in the severe coronary artery stenosis group (inclusion criteria: OCT showed coronary artery area stenosis ≥70.0%) and 89 patients in the control group (inclusion criteria: OCT showed coronary artery area stenosis &lt;50.0% or CCTA showed no coronary artery stenosis). A total of 46 patients were included in the MPI subgroup, including 10 patients in the severe myocardial ischemia group (inclusion criteria: MPI showed abnormal perfusion scores of at least one ventricular segment ≥3 points) and 36 patients in the control group (inclusion criteria: MPI showed abnormal perfusion scores of all ventricular segments ≤2 points). The Nomogram model was used to predict the results of patients in the two subgroups, and the results were compared with the OCT and MPI results. The sensitivity, specificity and Youden index were calculated. Results: The Nomogram model based on MCG had a sensitivity of 70.8%, a specificity of 85.4%, and a Youden index of 0.562 for predicting OCT results. The sensitivity, specificity and Youden index of Nomogram model for predicting MPI results were 70.0%, 72.2% and 0.422, respectively. Conclusions: The MCG-based Nomogram model has good prediction accuracy for the anatomical and functional evaluation of coronary artery lesions, which has potential application value.

Myocardial ischemia in patients with mild-to-moderate aortic stenosis: Interaction with cardiac remodeling and adverse events

Myocardial ischemia in patients with mild-to-moderate aortic stenosis: Interaction with cardiac remodeling and adverse events

Risk Stratification in Cardiac Sarcoidosis With Cardiac Positron Emission Tomography: A Systematic Review and Meta-Analysis

Risk Stratification in Cardiac Sarcoidosis With Cardiac Positron Emission Tomography: A Systematic Review and Meta-Analysis

The New Frontiers of Fetal Imaging: MRI Insights into Cardiovascular and Thoracic Structures.

Fetal magnetic resonance imaging (fMRI) represents a second-line imaging modality that provides multiparametric and multiplanar views that are crucial for confirming diagnoses, detecting associated pathologies, and resolving inconclusive ultrasound findings. The introduction of high-field magnets and new imaging sequences has expanded MRI's role in pregnancy management. Recent innovations in ECG-gating techniques have revolutionized the prenatal evaluation of congenital heart disease by synchronizing imaging with the fetal heartbeat, thus addressing traditional challenges in cardiac imaging. Fetal cardiac MRI (fCMR) is particularly valuable for assessing congenital heart diseases, especially when ultrasound is limited by poor imaging conditions. fCMR allows for detailed anatomical and functional evaluation of the heart and great vessels and is also useful for diagnosing additional anomalies and analyzing blood flow patterns, which can aid in understanding abnormal fetal brain growth and placental perfusion. This review emphasizes fMRI's potential in evaluating cardiac and thoracic structures, including various gating techniques like metric optimized gating, self-gating, and Doppler ultrasound gating. The review also covers the use of static and cine images for structural and functional assessments and discusses advanced techniques like 4D-flow MRI and T1 or T2 mapping for comprehensive flow quantification and tissue characterization.

Effect of acute intravenous beta-blocker administration on myocardial blood flow during same-day hybrid CCTA/PET imaging

This study aimed to evaluate the impact of acute intravenous beta-blocker administration on myocardial blood flow (MBF) during same-day hybrid coronary computed tomography angiography (CCTA) and 13N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI). Previous research on the discontinuation of oral beta-blockers before MPI has shown mixed results, with no studies yet exploring the acute intravenous administration in the context of same-day hybrid imaging. This retrospective study included patients with suspected chronic coronary syndromes undergoing same-day hybrid CCTA/13N-ammonia PET MPI. Exclusion criteria comprised coronary artery stenosis ≥ 50% or regional perfusion abnormalities on PET, and baseline oral beta-blocker medication. Intravenous metoprolol (up to 30 mg) was administered as needed for heart rate control before CCTA. MBF measurements were obtained at rest (rMBF) and during stress (sMBF), and myocardial flow reserve (MFR) was calculated. After excluding 281 patients, 154 were eligible for propensity-score matching, resulting in 108 patients divided into two equal groups based on beta-blocker administration. The groups showed no significant differences in baseline characteristics. Among those who received beta-blockers, there was a significant decrease in sMBF (2.21 [IQR 1.72–2.78] versus 2.46 [2.08–2.99] ml∙min−1∙g−1, p = 0.027) and MFR (3.46 [2.70–4.05] versus 3.79 [3.22–4.46], p = 0.030), respectively, compared to those who did not receive beta-blockers. In contrast, rMBF remained unaffected (0.65 [0.54–0.78] versus 0.64 [0.55–0.76] ml∙min−1∙g−1, p = 0.931). Acute intravenous beta-blocker administration significantly impacts MBF, leading to a slight reduction in sMBF and MFR. In contrast, rMBF appears unaffected, suggesting that beta-blockers primarily affect the coronary capacity to respond to vasodilators.

Treinamento Físico Reduz a Inflamação e a Fibrose e Preserva a Função e a Perfusão Miocárdica em um Modelo de Cardiomiopatia Chagásica Crônica

Abstract Background: Chronic Chagas cardiomyopathy (CCC) is caused by an inflammatory process induced by Trypanosoma cruzi, which leads to myocarditis with reactive and reparative fibrosis. CCC progresses with myocardial perfusion abnormalities and histopathological events that affect cardiorespiratory fitness (CRF). Objectives: We evaluated the effects of aerobic physical training (APT) on myocardial perfusion and on morphological and functional impairments related with inflammation and fibrosis in Syrian hamsters with CCC. As a secondary objective, we analyzed the cross-sectional areas of the skeletal muscle. Methods: Hamsters with CCC and their respective controls were divided into four groups: CCC sedentary, CCC-APT, sedentary control and APT control. Seven months after infection, the animals underwent echocardiography, myocardial perfusion scintigraphy and cardiopulmonary exercise testing. Moderate-intensity APT was performed for fifty minutes, five times a week, for eight weeks. Subsequently, the animals were reassessed. Histopathological analysis was conducted after the above-mentioned procedures. The level of significance was set at 5% in all analyses (p&lt;0.05). Results: CCC sedentary animals presented worse myocardial perfusion defects (MPD) over time, reduced left ventricle ejection fraction (LVEF) and showed more inflammation and fibrosis when compared to other groups (mixed ANOVA analysis). Conversely, APT was able to mitigate the progression of MPD, ameliorate inflammation and fibrosis and improve CRF efficiency in CCC-APT animals. Conclusions: Our study demonstrated that APT ameliorated cardiac dysfunction, MPD, and reduced inflammation and fibrosis in CCC hamster models. Additionally, CCC-SED animals presented skeletal muscle atrophy while CCC-APT animals showed preserved skeletal muscle CSA. Understanding APT's effects on CCC's pathophysiological dimensions is crucial for future research and therapeutic interventions.

Futile recanalization in patients with basilar artery occlusion: assessment of the underlying etiology and the role of perfusion imaging

BackgroundFutile recanalization (FR) after endovascular therapy (EVT) is common in basilar artery occlusion (BAO). The purpose of this study was to investigate the predictors of FR in the posterior circulation...