scholarly journals Compressed sensing acceleration of cardiac cine imaging allows reliable and reproducible assessment of volumetric and functional parameters of the left and right atrium

2021 ◽  
Author(s):  
Sebastian Altmann ◽  
Moritz C. Halfmann ◽  
Ibukun Abidoye ◽  
Basel Yacoub ◽  
Michaela Schmidt ◽  
...  
Keyword(s):  
Heart Failure ◽  
Compressed Sensing ◽  
Healthy Volunteers ◽  
Acquisition Time ◽  
Cine Imaging ◽  
Functional Evaluation ◽  
Altman Analysis ◽  
Bland Altman Analysis ◽  
Functional Parameters ◽  
And Function

Abstract Objectives To compare volumetric and functional parameters of the atria derived from highly accelerated compressed sensing (CS)–based cine sequences in comparison to conventional (Conv) cine imaging. Methods CS and Conv cine sequences were acquired in 101 subjects (82 healthy volunteers (HV) and 19 patients with heart failure with reduced ejection fraction (HFrEF)) using a 3T MR scanner in this single-center study. Time-volume analysis of the left (LA) and right atria (RA) were performed in both sequences to evaluate atrial volumes and function (total, passive, and active emptying fraction). Inter-sequence and inter- and intra-reader agreement were analyzed using correlation, intraclass correlation (ICC), and Bland-Altman analysis. Results CS-based cine imaging led to a 69% reduction of acquisition time. There was significant difference in atrial parameters between CS and Conv cine, e.g., LA minimal volume (LAVmin) (Conv 24.0 ml (16.7–32.7), CS 25.7 ml (19.2–35.2), p < 0.0001) or passive emptying fraction (PEF) (Conv 53.9% (46.7–58.4), CS 49.0% (42.0–54.1), p < 0.0001). However, there was high correlation between the techniques, yielding good to excellent ICC (0.76–0.99) and small mean of differences in Bland-Altman analysis (e.g. LAVmin − 2.0 ml, PEF 3.3%). Measurements showed high inter- (ICC > 0.958) and intra-rater (ICC > 0.934) agreement for both techniques. CS-based parameters (PEF AUC = 0.965, LAVmin AUC = 0.864) showed equivalent diagnostic ability compared to Conv cine imaging (PEF AUC = 0.989, LAVmin AUC = 0.859) to differentiate between HV and HFrEF. Conclusion Atrial volumetric and functional evaluation using CS cine imaging is feasible with relevant reduction of acquisition time, therefore strengthening the role of CS in clinical CMR for atrial imaging. Key Points • Reliable assessment of atrial volumes and function based on compressed sensing cine imaging is feasible. • Compressed sensing reduces scan time and has the potential to overcome obstacles of conventional cine imaging. • No significant differences for subjective image quality, inter- and intra-rater agreement, and ability to differentiate healthy volunteers and heart failure patients were detected between conventional and compressed sensing cine imaging.

scholarly journals Population-based input function for TSPO quantification and kinetic modeling with [11C]-DPA-713

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Mercy I. Akerele ◽  
Sara A. Zein ◽  
Sneha Pandya ◽  
Anastasia Nikolopoulou ◽  
Susan A. Gauthier ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Kinetic Analysis ◽  
Kinetic Modeling ◽  
Input Function ◽  
Brain Regions ◽  
Population Based ◽  
Patient Specific ◽  
Systematic Bias ◽  
Altman Analysis ◽  
Bland Altman Analysis

Abstract Introduction Quantitative positron emission tomography (PET) studies of neurodegenerative diseases typically require the measurement of arterial input functions (AIF), an invasive and risky procedure. This study aims to assess the reproducibility of [11C]DPA-713 PET kinetic analysis using population-based input function (PBIF). The final goal is to possibly eliminate the need for AIF. Materials and methods Eighteen subjects including six healthy volunteers (HV) and twelve Parkinson disease (PD) subjects from two [11C]-DPA-713 PET studies were included. Each subject underwent 90 min of dynamic PET imaging. Five healthy volunteers underwent a test-retest scan within the same day to assess the repeatability of the kinetic parameters. Kinetic modeling was carried out using the Logan total volume of distribution (VT) model. For each data set, kinetic analysis was performed using a patient-specific AIF (PSAIF, ground-truth standard) and then repeated using the PBIF. PBIF was generated using the leave-one-out method for each subject from the remaining 17 subjects and after normalizing the PSAIFs by 3 techniques: (a) Weightsubject×DoseInjected, (b) area under AIF curve (AUC), and (c) Weightsubject×AUC. The variability in the VT measured with PSAIF, in the test-retest study, was determined for selected brain regions (white matter, cerebellum, thalamus, caudate, putamen, pallidum, brainstem, hippocampus, and amygdala) using the Bland-Altman analysis and for each of the 3 normalization techniques. Similarly, for all subjects, the variabilities due to the use of PBIF were assessed. Results Bland-Altman analysis showed systematic bias between test and retest studies. The corresponding mean bias and 95% limits of agreement (LOA) for the studied brain regions were 30% and ± 70%. Comparing PBIF- and PSAIF-based VT estimate for all subjects and all brain regions, a significant difference between the results generated by the three normalization techniques existed for all brain structures except for the brainstem (P-value = 0.095). The mean % difference and 95% LOA is −10% and ±45% for Weightsubject×DoseInjected; +8% and ±50% for AUC; and +2% and ± 38% for Weightsubject×AUC. In all cases, normalizing by Weightsubject×AUC yielded the smallest % bias and variability (% bias = ±2%; LOA = ±38% for all brain regions). Estimating the reproducibility of PBIF-kinetics to PSAIF based on disease groups (HV/PD) and genotype (MAB/HAB), the average VT values for all regions obtained from PBIF is insignificantly higher than PSAIF (%difference = 4.53%, P-value = 0.73 for HAB; and %difference = 0.73%, P-value = 0.96 for MAB). PBIF also tends to overestimate the difference between PD and HV for HAB (% difference = 32.33% versus 13.28%) and underestimate it in MAB (%difference = 6.84% versus 20.92%). Conclusions PSAIF kinetic results are reproducible with PBIF, with variability in VT within that obtained for the test-retest studies. Therefore, VT assessed using PBIF-based kinetic modeling is clinically feasible and can be an alternative to PSAIF.

scholarly journals Population-Based Input Function for TSPO Quantification and Kinetic Modeling with [11C]-DPA-713

2021 ◽  
Author(s):  
Mercy Iyabode Akerele ◽  
Sara A. Zein ◽  
Sneha Pandya ◽  
Anastasia Nikolopoulou ◽  
Susan A. Gauthier ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Kinetic Analysis ◽  
Kinetic Modeling ◽  
Input Function ◽  
Brain Regions ◽  
Population Based ◽  
Patient Specific ◽  
Systematic Bias ◽  
Altman Analysis ◽  
Bland Altman Analysis

Abstract Introduction: Quantitative positron emission tomography (PET) studies of neurodegenerative diseases typically require the measurement of arterial input functions (AIF), an invasive and risky procedure. This study aims to assess the reproducibility of [11C]DPA-713 PET kinetic analysis using population-based input function (PBIF). The final goal is to possibly eliminate the need for AIF. Materials and Methods: Eighteen subjects including six healthy volunteers (HV) and twelve Parkinson disease (PD) subjects from two [11C]-DPA-713 PET studies were included. Each subject underwent 90 minutes of dynamic PET imaging. Five healthy volunteers underwent a test-retest scan within the same day to assess the repeatability of the kinetic parameters. Kinetic modeling was carried out using the Logan total volume of distribution (VT) model. For each data set, kinetic analysis was performed using a patient specific AIF (PSAIF, ground-truth standard), and then repeated using the PBIF. PBIF was generated using the leave-one-out method for each subject from the remaining 17 subjects, and after normalizing the PSAIFs by 3 techniques: (a) Weightsubject×DoseInjected (b) Area Under AIF Curve (AUC), and (c) Weightsubject×AUC. The variability in the total distribution volume (VT) measured with PSAIF, in the test/retest study were determined for selected brain regions (white matter, cerebellum, thalamus, caudate, putamen, pallidum, brainstem, hippocampus and amygdala) using the Bland-Altman analysis, and for each of the 3 normalization techniques. Similarly, for all subjects, the variabilities due to the use of PBIF were assessed.Results: Bland-Altman analysis showed systematic bias between test and retest studies. The corresponding mean bias and 95% limits of agreement (LOA) for the studied brain regions were 30% and ±70%. Comparing PBIF- and PSAIF-based VT estimate for all subjects and all brain regions, a significant difference between the results generated by the three normalization techniques existed for all brain structures except for the brainstem (P-value = 0.095). The mean % difference and 95% LOA is -10% and ±45% for Weightsubject×DoseInjected; +8% and ±50% for AUC; and +2% and ±38% for Weightsubject×AUC. In all cases, normalizing by Weightsubject×AUC yielded the smallest % bias and variability (% bias = ±2%; LOA = ±38% for all brain regions. Estimating the reproducibility of PBIF-kinetics to PSAIF based on disease groups (HV/PD) and genotype (MAB/ HAB), the average VT values for all regions obtained from PBIF is insignificantly higher than PSAIF (%difference = 4.53%, P-value = 0.73 for HAB; and %difference = 0.73%, P-value = 0.96 for MAB). PBIF also tends to overestimate the difference between PD and HV for HAB (%difference = 32.33% versus 13.28%) and underestimate it in MAB (%difference = 6.84% versus 20.92%). Conclusions: PSAIF kinetic results are reproducible with PBIF, with variability in VT within that obtained for the test-retest studies. Therefore, VT assessed using PBIF-based kinetic modeling is clinically feasible, and can be an alternative to PSAIF.

scholarly journals Limitations of a non-invasive model of the estimation of pulmonary vascular resistance by magnetic resonance imaging in patients with heart failure

2021 ◽  
Vol 22 (Supplement_2) ◽  
Author(s):  
V Vidal Urrutia ◽  
A Cubillos-Arango ◽  
P Garcia-Gonzalez ◽  
J Gradoli-Palmero ◽  
J Nunez-Villota ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Heart Failure ◽  
Magnetic Resonance ◽  
Pulmonary Vascular Resistance ◽  
Altman Analysis ◽  
Resonance Imaging ◽  
Bland Altman Analysis ◽  
Non Invasive ◽  
Patients With Heart Failure ◽  
The Mean

Abstract Funding Acknowledgements Type of funding sources: None. Introduction. Pulmonary vascular resistance (PVR) is a hemodynamic parameter with important diagnostic and prognostic implications in patients with heart failure. Currently the gold standard technique for its quantification is right heart catheterization (RHC). However, cardiovascular magnetic resonance imaging (CMR) has been postulated as a non-invasive alternative for its estimation. The aim of this study is to assess the accuracy of a non-invasive model of PVR estimated by CMR in a specific subgroup of patients with acute heart failure (AHF). Methods. Between January 2014 and December 2018, 108 patients with AHF who underwent RHC and CMR on the same day were prospectively included. PVR was assessed by CMR using the model: 19.38 - [4.62 x Ln mean pulmonary artery velocity - 0.08 x right ventricular ejection fraction (RVEF)]. During RHC, PVR were calculated using the ratio between transpulmonary gradient and cardiac output. We evaluated their correlation using the Spearman correlation coefficient, receiver operating characteristic [ROC] curves, and Bland-Altman analysis. Results. The mean age of our cohort was 65 ± 11 years and 64.8% were male. The median PVR (Wood Units, WU) assessed by CMR and RHC were 5.1 WU (3.4 - 6.8) and 3 WU (1.5 - 3.9); p &lt; 0.001, respectively. A weak correlation was observed between the PVR obtained by RHC and those obtained by CMR in our population (r = 0.21; p = 0.02). On Bland-Altman analysis, the mean bias was -1.7, and the 95% limits of agreement ranged from -10.02 to 6.6 WU. The area under the ROC curve for PVR assessed by CMR to detect PVR ³3 WU was 0.57, 95% confidence interval (CI): 0.47-0.68. Conclusions. In patients with AHF, the non-invasive estimation of PVR using CMR shows poor accuracy, as well as a limited capacity to discriminate increased PVR values.

scholarly journals Validation of an artificial intelligence-based tool for automated evaluation of RV size and function from ultrasound examinations

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
S Carasso ◽  
D Rosenmann ◽  
A Butnaro ◽  
L Alper-Suissa ◽  
S Igata ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Quantitative Methods ◽  
Point Of Care ◽  
Imaging Analysis ◽  
Altman Analysis ◽  
Limits Of Agreement ◽  
Private Company ◽  
Bland Altman Analysis ◽  
Echocardiographic Examination ◽  
And Function

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Study sponsored by DiA Imaging Analysis Background  The assessment of the right ventricular (RV) function is an essential part of every transthoracic echocardiographic examination. It plays an important role in the diagnosis and management of many diseases and conditions. In covid-19 patients, there is evidence showing that enlarged RV and abnormal Free Wall Strain (FWS) correlate with high mortality. Assessment of the RV in the Point of Care settings can assist the differential diagnosis and provide important clinical information in early stages, close to the onset of symptoms, however, it is done qualitatively by visual estimation and thus subjective and requires high level of expertise. The presented study aims to validate the use of a novel artificial intelligence tool (LVivo RV by DiA imaging analysis) that uses deep learning and image processing algorithms to automatically evaluate RV size and function from apical 4 chamber (4CH) focused or modified ultrasound clips. Methods  A retrospective study of 100 patients who underwent routine echocardiographic examination was conducted in three medical centers in US and Israel. The apical 4CH focused or modified clips were interpreted by experts to evaluate RV size and function. The End Diastolic Area (EDA) measured manually by two sonographers and the FWS measured by semi-automated Velocity Vector Imaging software (VVI by Siemens) were compared to the same parameters obtained automatically by the LVivo RV, using linear regression and Bland Altman analysis. Results  100 cases were included, 39% females and 61% males. Mean age was 64.7 [19-92]. Mean BMI was 28.1 [6.8-17.6]. 74% had pulmonary hypertension and 19% had lung disease. 36% were considered abnormal by their fractional area change values and 64% were considered normal. Three cases were non-interpretable by the physicians thus excluded from the analysis. The LVivo RV was able to process 99% of the cases. Excellent correlation was obtained for EDA between the sonographers" average of manual measurements and the automated EDA by LVivo RV with r = 0.92 (p &lt; 0.0001, 95%CI 0.88-0.94). The bias and limits of agreement for EDA were 0.87 ± 5.76cm^2. For FWS, 4 cases were manually excluded due to insufficient image quality. The Bland Altman analysis for FWS showed small bias and limits of agreement of 0.7 ± 12.2%. A very good correlation of r= 0.78, (95% CI 0.69-0.85) was found, indicating good compatibility between the methods. The specificity and sensitivity for FWS were 80% and 77% respectively, using an optimal cutoff value of -16%, and the overall agreement was 79%. Conclusions  The performance of LVivo RV demonstrated a very good agreement with manual and semi-automated quantitative methods for RV assessment. LVivo RV provides fast, accurate, objective and reproducible results and has the potential to be used at the Point of Care settings as a powerful tool for RV size and function evaluation. Abstract Figure.

Reply: Bland-Altman analysis for pupillometer comparison

2010 ◽  
Vol 36 (10) ◽  
pp. 1803-1804
Author(s):  
Magdalena Scheffel ◽  
Christoph Kuehne ◽  
Thomas Kohnen
Keyword(s):  
Altman Analysis ◽  
Bland Altman Analysis

scholarly journals The Role of Serum Chloride in Acute and Chronic Heart Failure: A Narrative Review

2021 ◽  
Vol 11 (2) ◽  
pp. 87-98
Author(s):  
Frederick Berro Rivera ◽  
Pia Alfonso ◽  
Jem Marie Golbin ◽  
Kevin Lo ◽  
Edgar Lerma ◽  
...  
Keyword(s):  
Heart Failure ◽  
Chloride Channel ◽  
Chloride Channels ◽  
Prognostic Value ◽  
Diuretic Therapy ◽  
Juxtaglomerular Apparatus ◽  
Sodium Chloride Cotransporter ◽  
Serum Chloride ◽  
And Function

Clinical guidelines include diuretics for the treatment of heart failure (HF), not to decrease mortality but to decrease symptoms and hospitalizations. More attention has been paid to the worse outcomes, including mortality, associated with continual diuretic therapy due to hypochloremia. Studies have revealed a pivotal role for serum chloride in the pathophysiology of HF and is now a target of treatment to decrease mortality. The prognostic value of serum chloride in HF has been the subject of much attention. Mechanistically, the macula densa, a region in the renal juxtaglomerular apparatus, relies on chloride levels to sense salt and volume status. The recent discovery of with-no-lysine (K) (WNK) protein kinase as an intracellular chloride sensor sheds light on the possible reason of diuretic resistance in HF. The action of chloride on WNKs results in the upregulation of the sodium-potassium-chloride cotransporter and sodium-chloride cotransporter receptors, which could lead to increased electrolyte and fluid reabsorption. Genetic studies have revealed that a variant of a voltage-sensitive chloride channel (CLCNKA) gene leads to almost a 50% decrease in current amplitude and function of the renal chloride channel. This variant increases the risk of HF. Several trials exploring the prognostic value of chloride in both acute and chronic HF have shown mostly positive results, some even suggesting a stronger role than sodium. However, so far, interventional trials exploring serum chloride as a therapeutic target have been largely inconclusive. This study is a review of the pathophysiologic effects of hypochloremia in HF, the genetics of chloride channels, and clinical trials that are underway to investigate novel approaches to HF management.

scholarly journals Quantitative and functional evaluation of endothelial progenitor cells in patients with cardiac amyloidosis

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
O Itzhaki Ben Zadok ◽  
D Leshem-Lev ◽  
T Ben-Gal ◽  
A Hamdan ◽  
N Schamroth-Pravda ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Mtt Assay ◽  
Cardiac Amyloidosis ◽  
Microvascular Dysfunction ◽  
Functional Evaluation ◽  
Endothelial Progenitor ◽  
Colony Forming Units ◽  
Study Population ◽  
And Function

Abstract Background Endothelial microvascular dysfunction is a known mechanism of injury in cardiac amyloidosis (CA), but evidence regarding the level and function of endothelial progenitor cells (EPCs) in patients with CA is lacking. Methods Study population included patients with light-chain or transthyretin (ATTR) CA. Patients with diagnosed heart failure and preserved ejection fraction (HFpEF) without monoclonal gammopathy and a 99mTc-DPD scan incompatible with TTR were used as controls. Blood circulating EPCs were assessed quantitatively by the expression of VEGFR-2(+), CD34(+) and CD133(+) using flow cytometry, and functionally by the formation of colony forming units (CFUs). MTT assay was used to demonstrate cell viability. Tests were repeated 3 months following the initiation of amyloid-suppressive therapies (either ATTR-stabilizer or targeted chemotherapy) in CA patients. Results Our preliminary cohort included 14 CA patients (median age 74 years, 62% ATTR CA). Patients with CA vs. patients with HFpEF (n=8) demonstrated lower expression of CD34(+)/VEGFR-2(+) cells [0.51% (IQR 0.4, 0.7) vs. 1.03% (IQR 0.6, 1.4), P=0.043] and CD133(+)/VEGFR-2(+) cells [0.35% (IQR 0.23, 0.52) to 1.07% (IQR 0.6, 1.5), P=0.003]. Functionally, no differences were noted between groups. Following the initiation of amyloid-suppressive therapies in CA patients, we observed the up-regulation of CD34(+)/VEGFR-2(+) cells [2.47% (IQR 2.1, 2.7), P&lt;0.001] and CD133(+)/VEGFR-2(+) cells [1.38% (IQR 1.1, 1.7), P=0.003]. Moreover, functionally, active EPCs were evident microscopically by their ability to form colonies (from 0.5 CFUs [IQR 0, 1.5) to 2 CFUs (IQR 1, 3.5), P=0.023]. EPCs' viability was demonstrated by an MTT assay [0.12 (IQR 0.04, 0.12) to 0.24 (IQR 0.16, 0.3), p=0.014]. Conclusions These preliminary results demonstrate reduced EPCs levels in CA patients indicating significant microvascular impairment. Amyloid-targeted therapies induce the activation of EPCs, thus possibly promoting endothelial regeneration. These findings may represent a novel mechanism of action of amyloid-suppressive therapies EPCs in CA patients and during therapy Funding Acknowledgement Type of funding source: None

scholarly journals Increased myocardial fat supply improves cardiac energetics and function in heart failure

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
W Watson ◽  
P.G Green ◽  
S Neubauer ◽  
O.J Rider
Keyword(s):  
Heart Failure ◽  
Creatine Kinase ◽  
Ejection Fraction ◽  
Funding Source ◽  
Cardiac Energetics ◽  
Fat Emulsion ◽  
Euglycaemic Clamp ◽  
Fat Infusion ◽  
And Function ◽  
Glucose Supply

Abstract Introduction The failing heart is starved of energy, in part accounting for its contractile dysfunction. Reduced uptake of fat and sugar required for energy production has frequently been demonstrated in heart failure, therefore altering metabolism of glucose and/or fat is therefore attractive as a therapy. We hypothesized increasing glucose supply would be beneficial over increasing fat supply so measured ATP usage (via PCr/ATP ratio and flux through creatine kinase) and cardiac function during fat emulsion infusion or euglycaemic hyperinsulinaemic clamp. Methods 11 patients with a diagnosis of heart failure and nonischaemic cardiomyopathy were recruited, mean age 66 (range 49–80), mean BMI 27.7 (range 21.3–37.5), F:M 3:8, 3 diabetic and 8 non-diabetic. On the first visit they had a baseline cardiac magnetic resonance (CMR), collecting cardiac volumes and function, then were randomised to receive either fat infusion or euglycaemic clamp. Following an hour of infusion, CMR was repeated followed by 31P cardiac magnetic resonance spectroscopy, then a dobutamine stress sequence at 65% maximum heart rate. They received the alternate infusion at the next visit. Results Data was normally distributed. Baseline ejection fraction was 37±9%. PCr/ATP ratio was greater with the fat infusion compared to euglycaemic clamp (1.82±0.26 vs 1.68±0.24, p=0.04). Fat emulsion infusion also brought about a greater ejection fraction increase over the baseline, compared to the euglycaemic clamp in which there was little difference (+5.3±5.3% vs −0.6±3.1%, p=0.004). Calculated cardiac work was greater in the fat infusion group than the Insulin/glucose group (682±156 L.mmHg/min vs 581±85 L.mmHg/min, p=0.009). There was no significant difference in creatine kinase first order rate constant (fat infusion 0.2±0.09/s vs euglycaemic clamp 0.16±0.07/s, p=0.32) nor creatine kinase flux (fat infusion 1.85±0.92 μmol/g/s vs euglycaemic clamp 1.46±0.58 μmol/g/s, p=0.22). The increment in cardiac output on stress over baseline was not significantly different between arms (fat infusion +3.39±3.07 L/min vs euglycaemic clamp +3.08±2.57 L/min, p=0.42). The PCr/ATP ratio showed positive correlation with the stress ejection fraction (R2=0.656, p=0.001), but not with resting ejection fraction. Conclusions Increased supply of fat to the myocardium brought about improved contractility and cardiac energetics compared to an increased glucose supply. The increase in PCr/ATP ratio would imply (given ATP concentrations are kept constant in the myocardium) there is a greater availability of phosphocreatine, suggesting increased mitochondrial ATP synthesis. These results were unexpected as it has traditionally been thought that increased glucose metabolism would yield greater cardiac function in the failing heart. These data suggest targeting myocardial fat metabolism may provide novel treatments for cardiac dysfunction. Figure 1 Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): British Heart Foundation

Sign in / Sign up

Export Citation Format

Share Document