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1.
Sensors (Basel) ; 24(9)2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38732822

ABSTRACT

Magnetic resonance (MR) with sodium (23Na) is a noninvasive tool providing quantitative biochemical information regarding physiology, cellular metabolism, and viability, with the potential to extend MR beyond anatomical proton imaging. However, when using clinical scanners, the low detectable 23Na signal and the low 23Na gyromagnetic ratio require the design of dedicated radiofrequency (RF) coils tuned to the 23Na Larmor frequency and sequences, as well as the development of dedicated phantoms for testing the image quality, and an MR scanner with multinuclear spectroscopy (MNS) capabilities. In this work, we propose a hardware and software setup for evaluating the potential of 23Na magnetic resonance imaging (MRI) with a clinical scanner. In particular, the reliability of the proposed setup and the reproducibility of the measurements were verified by multiple acquisitions from a 3T MR scanner using a homebuilt RF volume coil and a dedicated sequence for the imaging of a phantom specifically designed for evaluating the accuracy of the technique. The final goal of this study is to propose a setup for standardizing clinical and research 23Na MRI protocols.


Subject(s)
Magnetic Resonance Imaging , Phantoms, Imaging , Software , Magnetic Resonance Imaging/methods , Magnetic Resonance Imaging/instrumentation , Sodium/chemistry , Humans , Sodium Isotopes , Image Processing, Computer-Assisted/methods , Reproducibility of Results
2.
Brain Struct Funct ; 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38625557

ABSTRACT

The noradrenergic nucleus Locus Coeruleus (LC) is precociously involved in Alzheimer's Disease (AD) pathology, and its degeneration progresses during the course of the disease. Using Magnetic Resonance Imaging (MRI), researchers showed also in vivo in patients the disruption of LC, which can be observed both in Mild Cognitively Impaired individuals and AD demented patients. In this study, we report the results of a follow-up neuroradiological assessment, in which we evaluated the LC degeneration overtime in a group of cognitively impaired patients, submitted to MRI both at baseline and at the end of a 2.5-year follow-up. We found that a progressive LC disruption can be observed also in vivo, involving the entire nucleus and associated with clinical diagnosis. Our findings parallel neuropathological ones, which showed a continuous increase of neuronal death and volumetric atrophy within the LC with the progression of Braak's stages for neurofibrillary pathology. This supports the reliability of MRI as a tool for exploring the integrity of the central noradrenergic system in neurodegenerative disorders.

3.
Pediatr Cardiol ; 45(5): 998-1006, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38519622

ABSTRACT

We sought to evaluate the potential clinical role of 4D-flow cardiac magnetic resonance (CMR)-derived energetics and flow parameters in a cohort of patients' post-Fontan palliation. In patients with Fontan circulation who underwent 4D-Flow CMR, streamlines distribution was evaluated, as well a 4D-flow CMR-derived energetics parameters as kinetic energy (KE) and energy loss (EL) normalized by volume. EL/KE index as a marker of flow efficiency was also calculated. Cardiopulmonary exercise test (CPET) was also performed in a subgroup of patients. The population study included 55 patients (mean age 22 ± 11 years). The analysis of the streamlines revealed a preferential distribution of the right superior vena cava flow for the right pulmonary artery (62.5 ± 35.4%) and a mild preferential flow for the left pulmonary artery (52.3 ± 40.6%) of the inferior vena cave-pulmonary arteries (IVC-PA) conduit. Patients with heart failure (HF) presented lower IVC/PA-conduit flow (0.75 ± 0.5 vs 1.3 ± 0.5 l/min/m2, p = 0.004) and a higher mean flow-jet angle of the IVC-PA conduit (39.2 ± 22.8 vs 15.2 ± 8.9, p < 0.001) than the remaining patients. EL/KE index correlates inversely with VO2/kg/min: R: - 0.45, p = 0.01 peak, minute ventilation (VE) R: - 0.466, p < 0.01, maximal voluntary ventilation: R:0.44, p = 0.001 and positively with the physiological dead space to the tidal volume ratio (VD/VT) peak: R: 0.58, p < 0.01. From our data, lower blood flow in IVC/PA conduit and eccentric flow was associated with HF whereas higher EL/KE index was associated with reduced functional capacity and impaired lung function. Larger studies are needed to confirm our results and to further improve the prognostic role of the 4D-Flow CMR in this challenging population.


Subject(s)
Exercise Test , Fontan Procedure , Heart Defects, Congenital , Pulmonary Artery , Humans , Female , Male , Heart Defects, Congenital/surgery , Heart Defects, Congenital/physiopathology , Young Adult , Exercise Test/methods , Pulmonary Artery/diagnostic imaging , Pulmonary Artery/physiopathology , Adolescent , Adult , Magnetic Resonance Imaging, Cine/methods , Child , Vena Cava, Superior/diagnostic imaging , Blood Flow Velocity/physiology , Heart Failure/physiopathology , Heart Failure/surgery , Vena Cava, Inferior/diagnostic imaging
4.
J Neural Transm (Vienna) ; 131(2): 157-164, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38032367

ABSTRACT

Locus coeruleus (LC) is the main noradrenergic nucleus of the brain, and degenerates early in Parkinson's disease (PD). The objective of this study is to test whether degeneration of the LC is associated with orthostatic hypotension (OH) in PD. A total of 22 cognitively intact PD patients and 52 age-matched healthy volunteers underwent 3 T magnetic resonance (MRI) with neuromelanin-sensitive T1-weighted sequences (LC-MRI). For each subject, a template space-based LC-MRI was used to calculate LC signal intensity (LC contrast ratio-LCCR) and the estimated number of voxels (LCVOX) belonging to LC. Then, we compared the LC-MRI parameters in PD patients with OH (PDOH+) versus without OH (PDOH-) (matched for sex, age, and disease duration) using one-way analysis of variance followed by multiple comparison tests. We also tested for correlations between subject's LC-MRI features and orthostatic drop in systolic blood pressure (SBP). PDOH- and PDOH+ did not differ significantly (p > 0.05) based on demographics and clinical characteristics, except for blood pressure measurements and SCOPA-AUT cardiovascular domain (p < 0.05). LCCR and LCVOX measures were significantly lower in PD compared to HC, while no differences were observed between PDOH- and PDOH+. Additionally, no correlation was found between the LC-MRI parameters and the orthostatic drop in SBP or the clinical severity of autonomic symptoms (p > 0.05). Conversely, RBD symptom severity negatively correlated with several LC-MRI parameters. Our results failed to indicate a link between the LC-MRI features and the presence of OH in PD but confirmed a marked alteration of LC signal in PD patients.


Subject(s)
Hydroxides , Hypotension, Orthostatic , Parkinson Disease , Humans , Hypotension, Orthostatic/diagnostic imaging , Hypotension, Orthostatic/etiology , Locus Coeruleus/diagnostic imaging , Parkinson Disease/complications , Parkinson Disease/diagnostic imaging , Magnetic Resonance Imaging/methods
5.
J Digit Imaging ; 36(6): 2567-2577, 2023 12.
Article in English | MEDLINE | ID: mdl-37787869

ABSTRACT

Deep neural networks (DNNs) have already impacted the field of medicine in data analysis, classification, and image processing. Unfortunately, their performance is drastically reduced when datasets are scarce in nature (e.g., rare diseases or early-research data). In such scenarios, DNNs display poor capacity for generalization and often lead to highly biased estimates and silent failures. Moreover, deterministic systems cannot provide epistemic uncertainty, a key component to asserting the model's reliability. In this work, we developed a probabilistic system for classification as a framework for addressing the aforementioned criticalities. Specifically, we implemented a Bayesian convolutional neural network (BCNN) for the classification of cardiac amyloidosis (CA) subtypes. We prepared four different CNNs: base-deterministic, dropout-deterministic, dropout-Bayesian, and Bayesian. We then trained them on a dataset of 1107 PET images from 47 CA and control patients (data scarcity scenario). The Bayesian model achieved performances (78.28 (1.99) % test accuracy) comparable to the base-deterministic, dropout-deterministic, and dropout-Bayesian ones, while showing strongly increased "Out of Distribution" input detection (validation-test accuracy mismatch reduction). Additionally, both the dropout-Bayesian and the Bayesian models enriched the classification through confidence estimates, while reducing the criticalities of the dropout-deterministic and base-deterministic approaches. This in turn increased the model's reliability, also providing much needed insights into the network's estimates. The obtained results suggest that a Bayesian CNN can be a promising solution for addressing the challenges posed by data scarcity in medical imaging classification tasks.


Subject(s)
Deep Learning , Humans , Reproducibility of Results , Bayes Theorem , Neural Networks, Computer , Diagnostic Imaging
6.
Diagnostics (Basel) ; 13(20)2023 Oct 19.
Article in English | MEDLINE | ID: mdl-37892076

ABSTRACT

Background: Managing repaired tetralogy of Fallot (TOF) patients is still challenging despite the fact that published studies identified prognostic clinical or imaging data with rather good negative predictive accuracy but weak positive predictive accuracy. Heterogeneity of the initial anatomy, the surgical approach, and the complexity of the mechanism leading to dilation and ventricular dysfunction explain the challenge of predicting the adverse event in this population. Therefore, risk stratification and management of this population remain poorly standardized. Design: The CMR/CT WG of the Italian Pediatric Cardiology Society set up a multicenter observational clinical database of repaired TOF evaluations. This registry will enroll patients retrospectively and prospectively assessed by CMR for clinical indication in many congenital heart diseases (CHD) Italian centers. Data collection in a dedicated platform will include surgical history, clinical data, imaging data, and adverse cardiac events at 6 years of follow-up. Summary: The multicenter repaired TOF clinical database will collect data on patients evaluated by CMR in many CHD centers in Italy. The registry has been set up to allow future research studies in this population to improve clinical/surgical management and risk stratification of this population.

7.
J Cardiovasc Med (Hagerstown) ; 24(8): 552-560, 2023 08 01.
Article in English | MEDLINE | ID: mdl-37409600

ABSTRACT

BACKGROUND: Age-specific and gender-specific reference values for left ventricular (LV) and right ventricle volumes are available. The prognostic implications of the ratio between these volumes in heart failure and preserved ejection fraction (HFpEF) have never been evaluated. METHODS: We examined all HFpEF outpatients undergoing a cardiac magnetic resonance from 2011 to 2021. The left-to-right ventricular volume ratio (LRVR) was defined as the ratio between the LV and right ventricle end-diastolic volume indexes (LVEDVi/RVEDVi). RESULTS: Among 159 patients [median age 58 years (interquartile range 49-69), 64% men, LV ejection fraction 60% (54-70%)] the median LRVR was 1.21 (1.07-1.40). Over 3.5 years (1.5-5.0), 23 patients (15%) experienced all-cause death or heart failure hospitalization, and 22 (14%) cardiovascular death or heart failure hospitalization. The risk of all-cause death or heart failure hospitalization increased with an LRVR less than 1.0 or at least 1.4. An LRVR less than 1.0 was associated with a higher risk of all-cause death or heart failure hospitalization [hazard ratio 5.95, 95% confidence interval (CI) 1.67-21.28; P = 0.006] and cardiovascular death or heart failure hospitalization (hazard ratio 5.68, 95% CI 1.58-20.35; P = 0.008) as compared with LRVR 1.0-1.3. Furthermore, an LRVR at least 1.4 was associated with a higher risk of all-cause death or heart failure hospitalization (hazard ratio 4.10, 95% CI 1.58-10.61; P = 0.004) and cardiovascular death or heart failure hospitalization (hazard ratio 3.71, 95% CI 1.41-9.79; P = 0.008) as compared with LRVR 1.0-1.3. These results were confirmed in patients without dilation of either ventricle. CONCLUSION: LRVR values less than 1.0 or at least 1.4 are associated with worse outcomes in HFpEF. LRVR may become a valuable tool for risk prediction in HFpEF.


Subject(s)
Heart Failure , Male , Humans , Middle Aged , Female , Heart Failure/diagnostic imaging , Stroke Volume , Heart Ventricles/diagnostic imaging , Ventricular Function, Left , Prognosis , Hospitalization
8.
Curr Alzheimer Res ; 20(4): 277-288, 2023.
Article in English | MEDLINE | ID: mdl-37488756

ABSTRACT

BACKGROUND: The integrity of Locus Coeruleus can be evaluated in vivo using specific Magnetic Resonance Imaging sequences. While this nucleus has been shown to be degenerated both in post-mortem and in vivo studies in Alzheimer's Disease, for other neurodegenerative dementias such as Dementia with Lewy Bodies this has only been shown ex-vivo. OBJECTIVE: To evaluate the integrity of the Locus Coeruleus through Magnetic Resonance Imaging in patients suffering from Dementia with Lewy Bodies and explore the possible differences with the Locus Coeruleus alterations occurring in Alzheimer's Dementia. METHODS: Eleven patients with Dementia with Lewy Bodies and 35 with Alzheimer's Dementia were recruited and underwent Locus Coeruleus Magnetic Resonance Imaging, along with 52 cognitively intact, age-matched controls. Images were analyzed applying an already developed template-based approach; Locus Coeruleus signal was expressed through the Locus Coeruleus Contrast Ratio parameter, and a locoregional analysis was performed. RESULTS: Both groups of patients showed significantly lower values of Locus Coeruleus Contrast Ratio when compared to controls. A different pattern of spatial involvement was found; patients affected by Dementia with Lewy bodies showed global and bilateral involvement of the Locus Coeruleus, whereas the alterations in Alzheimer's Dementia patients were more likely to be localized in the rostral part of the left nucleus. CONCLUSIONS: Magnetic Resonance Imaging successfully detects widespread Locus Coeruleus degeneration in patients suffering from Dementia with Lewy Bodies. Further studies, in larger cohorts and in earlier stages of the disease, are needed to better disclose the potential diagnostic and prognostic role of this neuroradiological tool.

9.
Sci Rep ; 13(1): 8110, 2023 05 19.
Article in English | MEDLINE | ID: mdl-37208405

ABSTRACT

Narratives are paradigmatic examples of natural language, where nouns represent a proxy of information. Functional magnetic resonance imaging (fMRI) studies revealed the recruitment of temporal cortices during noun processing and the existence of a noun-specific network at rest. Yet, it is unclear whether, in narratives, changes in noun density influence the brain functional connectivity, so that the coupling between regions correlates with information load. We acquired fMRI activity in healthy individuals listening to a narrative with noun density changing over time and measured whole-network and node-specific degree and betweenness centrality. Network measures were correlated with information magnitude with a time-varying approach. Noun density correlated positively with the across-regions average number of connections and negatively with the average betweenness centrality, suggesting the pruning of peripheral connections as information decreased. Locally, the degree of the bilateral anterior superior temporal sulcus (aSTS) was positively associated with nouns. Importantly, aSTS connectivity cannot be explained by changes in other parts of speech (e.g., verbs) or syllable density. Our results indicate that the brain recalibrates its global connectivity as a function of the information conveyed by nouns in natural language. Also, using naturalistic stimulation and network metrics, we corroborate the role of aSTS in noun processing.


Subject(s)
Brain Mapping , Brain , Humans , Brain Mapping/methods , Brain/diagnostic imaging , Brain/physiology , Language , Temporal Lobe/physiology , Speech , Magnetic Resonance Imaging
10.
Eur Heart J Cardiovasc Imaging ; 24(9): 1222-1230, 2023 08 23.
Article in English | MEDLINE | ID: mdl-37070652

ABSTRACT

AIMS: We measured myocardial T2 values by a segmental approach in thalassaemia major (TM) patients, comparing such values against T2* values for the detection of myocardial iron overload (MIO), evaluating their potential in detecting subclinical inflammation, and correlating with clinical status. METHODS AND RESULTS: One-hundred and sixty-six patients (102 females, 38.29 ± 11.49years) enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network underwent magnetic resonance imaging for the assessment of hepatic, pancreatic, and cardiac iron overload (T2* technique), of biventricular function (cine images), and of replacement myocardial fibrosis [late gadolinium enhancement (LGE)]. T2 and T2* values were quantified in all 16 myocardial segments, and the global value was the mean of all segments. Global heart T2 values were significantly higher in TM than in a cohort of 80 healthy subjects. T2 and T2* values were significantly correlated. Out of the 25 patients with a decreased global heart T2* value, 11 (44.0%) had reduced T2 values. No patient with a normal T2* value had a decreased T2 value.Eleven (6.6%) patients had a decreased global heart T2 value, 74 (44.6%) a normal global heart T2 value, and 81 (48.8%) an increased global heart T2 value. Biventricular function was comparable amongst the three groups, whilst LGE was significantly more frequent in patients with reduced vs. increased global heart T2 value. Compared with the other two groups, patients with reduced T2 values had significantly higher hepatic and pancreatic iron deposition. CONCLUSION: In TM, T2 mapping does not offer any advantage in terms of sensitivity for MIO assessment but detects subclinical myocardial inflammation.


Subject(s)
Iron Overload , beta-Thalassemia , Female , Humans , Iron , beta-Thalassemia/diagnostic imaging , Contrast Media , Gadolinium , Myocardium , Iron Overload/diagnostic imaging , Magnetic Resonance Imaging/methods , Inflammation/diagnostic imaging
11.
Int J Cardiol ; 376: 139-146, 2023 04 01.
Article in English | MEDLINE | ID: mdl-36731634

ABSTRACT

BACKGROUND: We evaluated the prevalence of myocardial involvement by native T1 and T2 mapping, the diagnostic performance of mapping in addition to conventional Lake Louise Criteria (LLC), as well as correlations between mapping findings and clinical or conventional cardiovascular magnetic resonance (CMR) parameters in systemic sclerosis (SSc) patients. METHODS: Fifty-five SSc patients (52.31 ± 13.24 years, 81.8% female) and 55 age- and sex-matched healthy subjects underwent clinical, bio-humoral assessment, and CMR. The imaging protocol included: T2-weighted, early post-contrast cine sequences, native T1 and T2 mapping by a segmental approach, and late gadolinium enhancement (LGE) technique. RESULTS: Global myocardial T1 and T2 values were significantly higher in SSc patients than in healthy subjects. An increase in native T1 and/or T2 was present in the 62.1% of patients with normal conventional CMR techniques (negative LGE and T2-weighted images). Respectively, 13.5% and 59.6% of patients fulfilled original and updated LLC (overall agreement = 53.9%). Compared with patients with normal native T1, patients with increased T1 (40.0%) featured significantly higher left ventricular end-diastolic volume index and cardiac index, biventricular stroke volume indexes, and global heart T2 values, and more frequently had a history of digital ulcers. Biochemical and functional CMR parameters were comparable between patients with normal and increased T2 (61.8%). CONCLUSION: T1 and T2 mapping are sensitive parameters that should be included in the routine clinical assessment of SSc patients for detecting early/subclinical myocardial involvement.


Subject(s)
Contrast Media , Scleroderma, Systemic , Humans , Female , Male , Magnetic Resonance Imaging, Cine , Case-Control Studies , Gadolinium , Myocardium/pathology , Predictive Value of Tests , Ventricular Function, Left
12.
Neurobiol Aging ; 122: 12-21, 2023 02.
Article in English | MEDLINE | ID: mdl-36463849

ABSTRACT

Locus Coeruleus (LC) degeneration occurs early in Alzheimer's disease (AD) and this could affect several brain regions innervated by LC noradrenergic axon terminals, as these bear neuroprotective effects and modulate neurovascular coupling/neuronal activity. We used LC-sensitive Magnetic Resonance imaging (MRI) sequences enabling LC integrity quantification, and [18F]Fluorodeoxyglucose (FDG) PET, to investigate the association of LC-MRI changes with brain glucose metabolism in cognitively impaired patients (30 amnesticMCI and 13 demented ones). Fifteen cognitively intact age-matched controls (HCs) were submitted only to LC-MRI for comparison with patients. Voxel-wise regression analyses of [18F]FDG images were conducted using the LC-MRI parameters signal intensity (LCCR) and LC-belonging voxels (LCVOX). Both LCCR and LCVOX were significantly lower in patients compared to HCs, and were directly associated with [18F]FDG uptake in fronto-parietal cortical areas, mainly involving the left hemisphere (p < 0.001, kE > 100). These results suggest a possible association between LC degeneration and cortical hypometabolism in degenerative cognitive impairment with a prevalent left-hemispheric vulnerability, and that LC degeneration might be linked to large-scale functional network alteration in AD pathology.


Subject(s)
Alzheimer Disease , Humans , Alzheimer Disease/metabolism , Locus Coeruleus/pathology , Fluorodeoxyglucose F18/metabolism , Brain/metabolism , Neuroimaging , Positron-Emission Tomography/methods , Magnetic Resonance Imaging/methods
13.
Eur J Neurol ; 30(1): 32-46, 2023 01.
Article in English | MEDLINE | ID: mdl-36086917

ABSTRACT

BACKGROUND AND PURPOSE: Human neuropathological studies indicate that the pontine nucleus Locus Coeruleus (LC) undergoes significant and early degeneration in Alzheimer's disease. This line of evidence alongside experimental data suggests that the LC functional/structural decay may represent a critical factor for Alzheimer's disease pathophysiological and clinical progression. In the present prospective study, we used Magnetic Resonance Imaging (MRI) with LC-sensitive sequence (LC-MRI) to investigate in vivo the LC involvement in Alzheimer's disease progression, and whether specific LC-MRI features at baseline are associated with prognosis and cognitive performance in amnestic Mild Cognitive Impairment. METHODS: LC-MRI parameters were measured at baseline by a template-based method on 3.0-T magnetic resonance images in 34 patients with Alzheimer's disease dementia, 73 patients with amnestic Mild Cognitive Impairment, and 53 cognitively intact individuals. A thorough neurological and neuropsychological assessment was performed at baseline and 2.5-year follow-up. RESULTS: In subjects with Mild Cognitive Impairment who converted to dementia (n = 32), the LC intensity and number of LC-related voxels were significantly lower than in cognitively intact individuals, resembling those observed in demented patients. Such a reduction was not detected in Mild Cognitive Impairment individuals, who remained stable at follow-up. In Mild Cognitive Impairment subjects converting to dementia, LC-MRI parameter reduction was maximal in the rostral part of the left nucleus. Structural equation modeling analysis showed that LC-MRI parameters positively correlate with cognitive performance. CONCLUSIONS: Our findings highlight a potential role of LC-MRI for predicting clinical progression in Mild Cognitive Impairment and support the key role of LC degeneration in the Alzheimer clinical continuum.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Humans , Alzheimer Disease/pathology , Locus Coeruleus/diagnostic imaging , Prospective Studies , Disease Progression , Cognitive Dysfunction/pathology , Neuropsychological Tests , Magnetic Resonance Imaging/methods
14.
Eur Radiol ; 33(2): 1266-1276, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36066735

ABSTRACT

OBJECTIVES: Myocardial extracellular volume (ECV) by cardiovascular magnetic resonance (CMR) is a surrogate marker of diffuse fibrosis. We evaluated the association between ECV and demographics, CMR findings, and cardiac involvement in patients with thalassemia major (TM). METHODS: A total of 108 ß-TM patients (62 females, 40.16 ± 8.83 years), consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network, and 16 healthy subjects (6 females, 37.12 ± 16.13 years) underwent CMR. The protocol included assessment of T2*, native T1, and T2 values in all 16 myocardial segments for myocardial iron overload (MIO) quantification, cine images for left ventricular (LV) function quantification, post-contrast T1 mapping for ECV calculation, and late gadolinium enhancement (LGE) technique for replacement myocardial fibrosis detection. RESULTS: Global ECV values were significantly higher in females than in males. Global ECV values were significantly higher in patients with significant MIO (global heart T2* < 20 ms) than in patients without significant MIO, and both groups exhibited higher global ECV values than healthy subjects. No association was detected between native T1 and ECV values, while patients with reduced global heart T2 values showed significantly higher global ECV values than patients with normal and increased global heart T2. Global ECV values were not correlated with LV function/size and were comparable between patients with and without LGE. Compared to patients without heart failure, patients with a history of heart failure (N = 10) showed significantly higher global heart ECV values. CONCLUSION: In TM, increased myocardial ECV, potentially reflecting diffuse interstitial fibrosis, is associated with MIO and heart failure. KEY POINTS: • CMR-derived myocardial extracellular volume is increased in thalassemia major patients, irrespective of the presence of late gadolinium enhancement. • In thalassemia major, myocardial iron overload contributes to the increase in myocardial ECV, which potentially reflects diffuse interstitial fibrosis and is significantly associated with a history of heart failure.


Subject(s)
Heart Failure , Iron Overload , beta-Thalassemia , Male , Female , Humans , Contrast Media , beta-Thalassemia/complications , Gadolinium , Magnetic Resonance Imaging, Cine , Myocardium/pathology , Heart Failure/diagnostic imaging , Heart Failure/pathology , Iron Overload/complications , Iron Overload/diagnostic imaging , Fibrosis , Ventricular Function, Left , Predictive Value of Tests
15.
J Cardiovasc Magn Reson ; 24(1): 62, 2022 11 28.
Article in English | MEDLINE | ID: mdl-36437452

ABSTRACT

BACKGROUND: Segmentation of cardiovascular magnetic resonance (CMR) images is an essential step for evaluating dimensional and functional ventricular parameters as ejection fraction (EF) but may be limited by artifacts, which represent the major challenge to automatically derive clinical information. The aim of this study is to investigate the accuracy of a deep learning (DL) approach for automatic segmentation of cardiac structures from CMR images characterized by magnetic susceptibility artifact in patient with cardiac implanted electronic devices (CIED). METHODS: In this retrospective study, 230 patients (100 with CIED) who underwent clinically indicated CMR were used to developed and test a DL model. A novel convolutional neural network was proposed to extract the left ventricle (LV) and right (RV) ventricle endocardium and LV epicardium. In order to perform a successful segmentation, it is important the network learns to identify salient image regions even during local magnetic field inhomogeneities. The proposed network takes advantage from a spatial attention module to selectively process the most relevant information and focus on the structures of interest. To improve segmentation, especially for images with artifacts, multiple loss functions were minimized in unison. Segmentation results were assessed against manual tracings and commercial CMR analysis software cvi42(Circle Cardiovascular Imaging, Calgary, Alberta, Canada). An external dataset of 56 patients with CIED was used to assess model generalizability. RESULTS: In the internal datasets, on image with artifacts, the median Dice coefficients for end-diastolic LV cavity, LV myocardium and RV cavity, were 0.93, 0.77 and 0.87 and 0.91, 0.82, and 0.83 in end-systole, respectively. The proposed method reached higher segmentation accuracy than commercial software, with performance comparable to expert inter-observer variability (bias ± 95%LoA): LVEF 1 ± 8% vs 3 ± 9%, RVEF - 2 ± 15% vs 3 ± 21%. In the external cohort, EF well correlated with manual tracing (intraclass correlation coefficient: LVEF 0.98, RVEF 0.93). The automatic approach was significant faster than manual segmentation in providing cardiac parameters (approximately 1.5 s vs 450 s). CONCLUSIONS: Experimental results show that the proposed method reached promising performance in cardiac segmentation from CMR images with susceptibility artifacts and alleviates time consuming expert physician contour segmentation.


Subject(s)
Artifacts , Artificial Intelligence , Humans , Retrospective Studies , Predictive Value of Tests , Magnetic Resonance Imaging/methods , Attention
16.
J Cardiovasc Magn Reson ; 24(1): 48, 2022 08 18.
Article in English | MEDLINE | ID: mdl-35978351

ABSTRACT

Quantitative susceptibility mapping (QSM) is a powerful, non-invasive, magnetic resonance imaging (MRI) technique that relies on measurement of magnetic susceptibility. So far, QSM has been employed mostly to study neurological disorders characterized by iron accumulation, such as Parkinson's and Alzheimer's diseases. Nonetheless, QSM allows mapping key indicators of cardiac disease such as blood oxygenation and myocardial iron content. For this reason, the application of QSM offers an unprecedented opportunity to gain a better understanding of the pathophysiological changes associated with cardiovascular disease and to monitor their evolution and response to treatment. Recent studies on cardiovascular QSM have shown the feasibility of a non-invasive assessment of blood oxygenation, myocardial iron content and myocardial fibre orientation, as well as carotid plaque composition. Significant technical challenges remain, the most evident of which are related to cardiac and respiratory motion, blood flow, chemical shift effects and susceptibility artefacts. Significant work is ongoing to overcome these challenges and integrate the QSM technique into clinical practice in the cardiovascular field.


Subject(s)
Iron , Magnetic Resonance Imaging , Brain , Heart , Humans , Magnetic Resonance Imaging/methods , Predictive Value of Tests
17.
Int J Cardiol ; 365: 100-105, 2022 10 15.
Article in English | MEDLINE | ID: mdl-35926642

ABSTRACT

BACKGROUND: The impact of increasing temperatures on renal function in heart failure (HF) outpatients has never been specifically analyzed. METHODS: We retrieved creatinine and estimated glomerular filtration rate (eGFR) values of all HF outpatients followed at a HF clinic and temperature data from 2002 to 2021. For each patient and each year we averaged values of creatinine, eGFR and monthly temperatures during summer and the rest of the year. RESULTS: The study cohort included 2167 HF patients undergoing 25,865 elective visits, with a median of 14 visits for each patient (interquartile range 7-23). At the first visit, patients (70% men) had an age of 67 ± 13 years, and a left ventricular ejection fraction of 35 ± 14%. Creatinine was 1.25 ± 0.51 mg/dL, and eGFR was 65 ± 25 mL/min/1.73 m2. When pooling together all average values of creatinine and eGFR measured during summer or in the rest of the year, creatinine was significantly higher in summer (difference 0.04, 95% confidence interval [CI] 0.04 to 0.05, p < 0.001), and eGFR was slightly lower (difference - 2.0, 95% CI -2.3 to -1.8, p < 0.001). Temperature rise during summer increased from 2002 to 2021. The absolute (Δ) and percent (Δ%) elevation in temperature during summer displayed independent associations with Δ and Δ% creatinine and eGFR after adjusting for age, sex, plasma creatinine, and HF therapies. CONCLUSIONS: The magnitude of temperature elevation during summer has increased over 20 years. This elevation correlates with the decline in renal function during summer. This might be an example of how global warming is affecting human health.


Subject(s)
Heart Failure , Ventricular Function, Left , Aged , Aged, 80 and over , Creatinine , Female , Global Warming , Glomerular Filtration Rate , Humans , Kidney/physiology , Male , Middle Aged , Stroke Volume
18.
Front Cardiovasc Med ; 9: 887248, 2022.
Article in English | MEDLINE | ID: mdl-35898267

ABSTRACT

Background: Left ventricular (LV) remodeling consists in maladaptive changes in cardiac geometry and function following an insult such as ST-segment elevation myocardial infarction (STEMI). Interventions able to prevent LV remodeling after a STEMI are expected to improve the outcome of this condition. Paroxetine has inhibitory effects on GRK2, also known as beta-adrenergic receptor kinase 1 (ADRBK1). This drug does not yield beneficial effects on LV remodeling in patients with STEMI and LV ejection fraction ≤ 45%. Methods: We compared the molecular effects of paroxetine and drugs for neurohormonal antagonism (beta-blockers, angiotensin converting enzyme inhibitors/angiotensin receptor blockers, mineralocorticoid receptor antagonists), using a bioinformatic approach integrating transcriptomic data in a swine model of post-MI and available evidence from the literature and massive public databases. Results: Among standard therapies for MI, beta-blockers are the only ones acting directly upon GKR2, but the mechanism of action overlaps with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers with respect to the AT2R-mediated anti-hypertensive response. Moreover, beta-blockers could have anti-fibrotic and anti-inflammatory effects through the regulation of myocyte-specific enhancer factors, endothelins and chemokines. Conclusion: The additive benefit of paroxetine on the background of the standard therapy for STEMI, which includes beta-blockers, is expected to be limited. Nonetheless, paroxetine becomes particularly interesting when a beta-blocker is contraindicated (for example, in hypotensive individuals) or poorly tolerated.

19.
Int J Cardiol ; 364: 141-147, 2022 10 01.
Article in English | MEDLINE | ID: mdl-35718011

ABSTRACT

BACKGROUND: Clinical and prognostic role of cardiac magnetic resonance (CMR) in adult population with hypertrophic cardiomyopathy (HCM) have been largely assessed. We sought to investigate the role of CMR for predicting cardiovascular events in children with HCM. METHODS: CMR was performed in 116 patients with HCM (37 sarcomeric mutations, 31 other mutations, mean age 10.4 ± 4.3 yrs). CMR protocol included cine imaging for evaluation of morphology and function and late gadolinium enhancement (LGE). Hard cardiac events (sustained VT, resuscitated cardiac arrest, sudden cardiac death, end-stage heart failure, heart transplant and appropriate ICD intervention) were recorded through a median follow-up of 4 (1-7) years. RESULTS: During follow-up 21 heart cardiac events occurred. At maximal-rank statistic the optimal cut-point for LGE extent for predicting events was ≥2%. Syncope, non-sustained ventricular tachycardia (NSVT) and LGE extent ≥2% were independent predictors of events. At Harrel's C statistic combination of LGE extent ≥2% and syncope was the strongest model for predicting events. HR of patients with LGE extent ≥2% and no history of syncope was 3.6 (1.1-12.2) that increased to 37.6 (5.4-161) in those with LGE extent ≥2% and syncope. The median time dependent AUC of LGE extent (0.88, 95% CI 0.86-0.89) was significantly higher than that of syncope (0.63, 95% CI 0.61-0.66, p < 0.0001) and NSVT (0.52, 95% CI 0.50-0.53, p < 0.0001). CONCLUSIONS: In children with HCM, LGE and syncope were independent predictors of hard cardiac events at follow-up.


Subject(s)
Cardiomyopathy, Hypertrophic , Gadolinium , Adolescent , Adult , Cardiomyopathy, Hypertrophic/diagnostic imaging , Cardiomyopathy, Hypertrophic/pathology , Child , Contrast Media , Humans , Magnetic Resonance Imaging , Magnetic Resonance Imaging, Cine , Myocardium/pathology , Predictive Value of Tests , Prognosis , Risk Factors , Syncope
20.
Sci Rep ; 12(1): 4691, 2022 03 18.
Article in English | MEDLINE | ID: mdl-35304529

ABSTRACT

Left ventricular (LV) remodeling after myocardial infarction (MI) is promoted by an intense fibrotic response, which could be targeted by the anti-fibrotic drug pirfenidone. We explored the relationship between protein modulation by pirfenidone and post-MI remodeling, based on molecular information and transcriptomic data from a swine model of MI. We identified 6 causative motives of post-MI remodeling (cardiomyocyte cell death, impaired myocyte contractility, extracellular matrix remodeling and fibrosis, hypertrophy, renin-angiotensin-aldosterone system activation, and inflammation), 4 pirfenidone targets and 21 bioflags (indirect effectors). Pirfenidone had a more widespread action than gold-standard drugs, encompassing all 6 motives, with prominent effects on p38γ-MAPK12, the TGFß1-SMAD2/3 pathway and other effector proteins such as matrix metalloproteases 2 and 14, PDGFA/B, and IGF1. A bioinformatic approach allowed to identify several possible mechanisms of action of pirfenidone with beneficial effects in the post-MI LV remodeling, and suggests additional effects over guideline-recommended therapies.


Subject(s)
Computational Biology , Myocardial Infarction , Animals , Fibrosis , Myocardial Infarction/metabolism , Myocardium/metabolism , Pyridones/metabolism , Pyridones/pharmacology , Pyridones/therapeutic use , Swine , Ventricular Function, Left , Ventricular Remodeling
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