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1.
Acta Radiol ; : 2841851241240446, 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38630492

ABSTRACT

BACKGROUND: Dynamic myocardial computed tomography perfusion (CTP) is a novel imaging technique that increases the applicability of CT for cardiac imaging; however, the scanning requires a substantial radiation dose. PURPOSE: To investigate the feasibility of dose reduction in dynamic CTP by comparing all-heartbeat acquisitions to periodic skipping of heartbeats. MATERIAL AND METHODS: We retrieved imaging data of 38 dynamic CTP patients and created new datasets with every fourth, third or second beat (Skip1:4, Skip1:3, Skip1:2, respectively) removed. Seven observers evaluated the resulting images and perfusion maps for perfusion deficits. The mean blood flow (MBF) in each of the 16 myocardial segments was compared per skipped-beat level, normalized by the respective MBF for the full dose, and averaged across patients. The number of segments/cases whose MBF was <1.0 mL/g/min were counted. RESULTS: Out of 608 segments in 38 cases, the total additional number of false-negative (FN) segments over those present in the full-dose acquisitions and the number of additional false-positive cases were shown as acquisition (segment [%], case): Skip1:4: 7 (1.2%, 1); Skip1:3: 12 (2%, 3), and Skip1:2: 5 (0.8%, 2). The variability in quantitative MBF analysis in the repeated analysis for the reference condition resulted in 8 (1.3%) additional FN segments. The normalized results show a comparable MBF across all segments and patients, with relative mean MBFs as 1.02 ± 0.16, 1.03 ± 0.25, and 1.06 ± 0.30 for the Skip1:4, Skip1:3, and Skip1:2 protocols, respectively. CONCLUSION: Skipping every second beat acquisition during dynamic myocardial CTP appears feasible and may result in a radiation dose reduction of 50%. Diagnostic performance does not decrease after removing 50% of time points in dynamic sequence.

2.
Article in English | MEDLINE | ID: mdl-38306632

ABSTRACT

AIMS: To compare the novel 2D multi-venc and 4D flow acquisitions with the standard 2D flow acquisition for the assessment of paravalvular regurgitation (PVR) after TAVR using cardiac magnetic resonance (CMR)-derived regurgitant fraction (RF). METHODS AND RESULTS: In this prospective study, patients underwent CMR one month after TAVR to assess PVR using 2D multi-venc and 4D flow, in addition to standard 2D flow. Scatterplots and Bland-Altman plots were used to assess correlation and visualize agreement between techniques. Reproducibility of measurements was assessed with intraclass correlation coefficients. The study included 21 patients (mean age, 80 years ± 5 [SD], 9 men). Mean RF was 11.7 ± 10.0% using standard 2D flow, 10.6 ± 7.0% using 2D multi-venc flow, and 9.6 ± 7.3% using 4D flow. There was a very strong correlation between the RFs assessed with 2D multi-venc and standard 2D flow (r = 0.88, p < 0.001), and a strong correlation between the RFs assessed with 4D flow and standard 2D flow (r = 0.74, p < 0.001). Bland-Altman plots revealed no significant bias between the RFs (2D multi-venc: 1.3%; 4D flow: 0.3%). Intra- and interobserver reproducibility for 2D multi-venc flow were 0.98 and 0.97, respectively; and 0.92 and 0.90 for 4D flow, respectively. CONCLUSION: 2D multi-venc and 4D flow produce accurate quantification of PVR after TAVR. The fast acquisition of the 2D multi-venc sequence, and the free-breathing acquisition with retrospective plane selection of the 4D flow sequence provide useful advantages in clinical practice, especially in the frail TAVR population.

3.
Radiology ; 310(1): e230981, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38193833

ABSTRACT

Background Multiple commercial artificial intelligence (AI) products exist for assessing radiographs; however, comparable performance data for these algorithms are limited. Purpose To perform an independent, stand-alone validation of commercially available AI products for bone age prediction based on hand radiographs and lung nodule detection on chest radiographs. Materials and Methods This retrospective study was carried out as part of Project AIR. Nine of 17 eligible AI products were validated on data from seven Dutch hospitals. For bone age prediction, the root mean square error (RMSE) and Pearson correlation coefficient were computed. The reference standard was set by three to five expert readers. For lung nodule detection, the area under the receiver operating characteristic curve (AUC) was computed. The reference standard was set by a chest radiologist based on CT. Randomized subsets of hand (n = 95) and chest (n = 140) radiographs were read by 14 and 17 human readers, respectively, with varying experience. Results Two bone age prediction algorithms were tested on hand radiographs (from January 2017 to January 2022) in 326 patients (mean age, 10 years ± 4 [SD]; 173 female patients) and correlated strongly with the reference standard (r = 0.99; P < .001 for both). No difference in RMSE was observed between algorithms (0.63 years [95% CI: 0.58, 0.69] and 0.57 years [95% CI: 0.52, 0.61]) and readers (0.68 years [95% CI: 0.64, 0.73]). Seven lung nodule detection algorithms were validated on chest radiographs (from January 2012 to May 2022) in 386 patients (mean age, 64 years ± 11; 223 male patients). Compared with readers (mean AUC, 0.81 [95% CI: 0.77, 0.85]), four algorithms performed better (AUC range, 0.86-0.93; P value range, <.001 to .04). Conclusions Compared with human readers, four AI algorithms for detecting lung nodules on chest radiographs showed improved performance, whereas the remaining algorithms tested showed no evidence of a difference in performance. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Omoumi and Richiardi in this issue.


Subject(s)
Artificial Intelligence , Software , Humans , Female , Male , Child , Middle Aged , Retrospective Studies , Algorithms , Lung
4.
Int J Cardiol ; 388: 131162, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37433407

ABSTRACT

BACKGROUND: Left ventricular (LV) strain and rotation are emerging functional markers for early detection of LV dysfunction and have been associated with the burden of myocardial fibrosis in several disease states. This study examined the association between LV deformation (i.e., LV strain and rotation) and extent and location of LV myocardial fibrosis in pediatric patients with Duchenne muscular dystrophy (DMD). METHODS AND RESULTS: 34 pediatric patients with DMD underwent cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) to assess LV myocardial fibrosis. Offline CMR feature-tracking analysis was used to assess global and segmental longitudinal and circumferential LV strain, and LV rotation. Patients with fibrosis (n = 18, 52.9%) were older than those without fibrosis (14 ± 3 years (yrs) vs 11 ± 2 yrs., p = 0.01). There was no significant difference in LV ejection fraction (LVEF) between subjects with and without fibrosis (54 ± 6% vs 56 ± 4%, p = 0.18). However, lower endocardial global circumferential strain (GCS), but not LV rotation, was associated with presence of fibrosis (adjusted Odds Ratio 1.25 [95% CI 1.01-1.56], p = 0.04). Both GCS and global longitudinal strain correlated with the extent of fibrosis (r = .52, p = 0.03 and r = .75, p < 0.01, respectively). Importantly, segmental strain did not seem to correspond to location of fibrosis. CONCLUSION: A lower global, but not segmental, strain is associated with presence and extent of LV myocardial fibrosis in pediatric DMD patients. Therefore, strain parameters might detect structural myocardial alterations, however currently more research is needed to evaluate its value (e.g., prognostic) in clinical practice.


Subject(s)
Cardiomyopathies , Muscular Dystrophy, Duchenne , Humans , Child , Contrast Media , Muscular Dystrophy, Duchenne/complications , Muscular Dystrophy, Duchenne/diagnostic imaging , Magnetic Resonance Imaging, Cine/methods , Gadolinium , Cardiomyopathies/diagnosis , Myocardium/pathology , Ventricular Function, Left , Stroke Volume , Fibrosis
5.
Eur Radiol ; 33(8): 5509-5525, 2023 Aug.
Article in English | MEDLINE | ID: mdl-36997751

ABSTRACT

In patients with suspected coronary artery disease (CAD), dynamic myocardial computed tomography perfusion (CTP) imaging combined with coronary CT angiography (CTA) has become a comprehensive diagnostic examination technique resulting in both anatomical and quantitative functional information on myocardial blood flow, and the presence and grading of stenosis. Recently, CTP imaging has been proven to have good diagnostic accuracy for detecting myocardial ischemia, comparable to stress magnetic resonance imaging and positron emission tomography perfusion, while being superior to single photon emission computed tomography. Dynamic CTP accompanied by coronary CTA can serve as a gatekeeper for invasive workup, as it reduces unnecessary diagnostic invasive coronary angiography. Dynamic CTP also has good prognostic value for the prediction of major adverse cardiovascular events. In this article, we will provide an overview of dynamic CTP, including the basics of coronary blood flow physiology, applications and technical aspects including protocols, image acquisition and reconstruction, future perspectives, and scientific challenges. KEY POINTS: • Stress dynamic myocardial CT perfusion combined with coronary CTA is a comprehensive diagnostic examination technique resulting in both anatomical and quantitative functional information. • Dynamic CTP imaging has good diagnostic accuracy for detecting myocardial ischemia comparable to stress MRI and PET perfusion. • Dynamic CTP accompanied by coronary CTA may serve as a gatekeeper for invasive workup and can guide treatment in obstructive coronary artery disease.


Subject(s)
Coronary Artery Disease , Coronary Stenosis , Fractional Flow Reserve, Myocardial , Myocardial Ischemia , Myocardial Perfusion Imaging , Humans , Predictive Value of Tests , Coronary Angiography/methods , Tomography, X-Ray Computed/methods , Myocardial Ischemia/diagnostic imaging , Computed Tomography Angiography , Myocardial Perfusion Imaging/methods
6.
Eur Heart J Cardiovasc Imaging ; 24(8): 1072-1081, 2023 07 24.
Article in English | MEDLINE | ID: mdl-36915984

ABSTRACT

AIMS: Paravalvular regurgitation (PVR) is a common complication after transcatheter aortic valve replacement (TAVR) that poses an increased risk of rehospitalization for heart failure and mortality. The aim of this study was to assess the accuracy of haemodynamic indices to predict relevant PVR. METHODS AND RESULTS: In this prospective single-centre clinical trial, four haemodynamic indices of PVR measured during TAVR were assessed for their correlation with gold standard cardiac magnetic resonance (CMR)-derived regurgitant fraction (CMR-RF) at 1 month follow-up: diastolic delta (DD), heart rate-adjusted diastolic delta (HR-DD), aortic regurgitation index (ARI), and aortic regurgitation index ratio (ARI ratio). These haemodynamic indices were analysed for their ability to predict relevant PVR (defined as CMR-RF > 20%) using receiver operating characteristic (ROC) curves with corresponding area under the ROC curves (AUCs). A total of 77 patients were included and had CMR performed 41 ± 14 days after TAVR. Mean CMR-RF was 12.4 ± 9.3%. Fifteen (19.5%) patients had CMR-RF > 20%. DD had the best correlation with CMR-RF and the highest AUC to predict relevant PVR (0.82; 95% CI, 0.72-0.92), followed by HR-DD (AUC 0.78; 95% CI, 0.67-0.89), ARI (AUC 0.78; 95% CI, 0.66-0.89), and ARI ratio (AUC 0.65; 95% CI, 0.49-0.81). The optimal cut-off value for DD was 32 mmHg, with sensitivity of 69% and specificity of 77% in predicting relevant PVR. CONCLUSION: DD measured during TAVR best predicts relevant PVR. Correction for heart rate (HR-DD) or systolic blood pressure (ARI, ARI ratio) did not improve this predictive value.


Subject(s)
Aortic Valve Insufficiency , Aortic Valve Stenosis , Heart Valve Prosthesis , Transcatheter Aortic Valve Replacement , Humans , Aortic Valve/diagnostic imaging , Aortic Valve/surgery , Aortic Valve Insufficiency/diagnostic imaging , Aortic Valve Insufficiency/etiology , Aortic Valve Stenosis/diagnostic imaging , Aortic Valve Stenosis/surgery , Aortic Valve Stenosis/complications , Heart Valve Prosthesis/adverse effects , Magnetic Resonance Spectroscopy/adverse effects , Prospective Studies , Severity of Illness Index , Transcatheter Aortic Valve Replacement/adverse effects , Transcatheter Aortic Valve Replacement/methods , Treatment Outcome
7.
Pediatr Cardiol ; 44(1): 75-85, 2023 Jan.
Article in English | MEDLINE | ID: mdl-35727332

ABSTRACT

With the trend towards childhood surgery in patients with Ebstein anomaly (EA), thorough imaging is crucial for patient selection. This study aimed to assess biventricular function by echocardiography and cardiac magnetic resonance (CMR) and compare EA severity classifications. Twenty-three patients (8-17 years) underwent echocardiography and CMR. Echocardiographic parameters included tricuspid annular plane systolic excursions (TAPSE), fractional area change of the functional right ventricle (fRV-FAC), fRV free wall peak systolic myocardial velocity (fRVs'), and tricuspid regurgitation (TR). End-diastolic and end-systolic volume (EDV resp. ESV), fRV- and LV ejection fraction (EF) and TR were obtained by CMR. EA severity classifications included displacement index, Celermajer index and the total-right/left-volume index. Median fRV-FAC was 38% (IQR 33-42). TAPSE and fRVs' were reduced in 39% and 75% of the patients, respectively. Echocardiographic TR was visually graded as mild, moderate, or severe in nine, six and eight patients, respectively. By CMR, median fRVEF was 49% (IQR 36-58) and TR was graded as mild, moderate, or severe in nine, twelve and two patients, respectively. In 70% of cases, fRV-EDV was higher than LV-EDV. LVEF was decreased in 17 cases (74%). There was excellent correlation between echocardiography-derived fRV-FAC and CMR-derived fRVEF (rho = 0.812, p < 0.001). While echocardiography is a versatile tool in the complex geometry of the Ebstein heart, it has limitations. CMR offers a total overview and has the advantage of reliable volume assessment of both ventricles. Comprehensive evaluation of pediatric patients with EA may therefore require a synergistic implementation of echocardiography and CMR.


Subject(s)
Ebstein Anomaly , Echocardiography , Magnetic Resonance Imaging , Adolescent , Child , Humans , Ebstein Anomaly/diagnostic imaging , Heart Ventricles/diagnostic imaging , Reproducibility of Results , Tricuspid Valve Insufficiency/diagnostic imaging , Stroke Volume
8.
Acta Radiol ; 64(3): 999-1006, 2023 Mar.
Article in English | MEDLINE | ID: mdl-35765201

ABSTRACT

BACKGROUND: Dynamic myocardial computed tomography perfusion (CTP) is a novel technique able to depict cardiac ischemia. PURPOSE: To evaluate the impact of a four-dimensional noise reduction filter (similarity filter [4D-SF]) on image quality in dynamic CTP imaging, allowing for substantial radiation dose reduction. MATERIAL AND METHODS: Dynamic CTP datasets of 30 patients (16 women) with suspected coronary artery disease, acquired with a 320-slice CT system, were retrieved, reconstructed with the deep learning-based algorithm of the system (DLR), and filtered with the 4D-SF. For each case, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in six regions of interest (33-38mm2) were calculated before and after filtering, in four-chamber and short-axis views, and t-tested. Furthermore, six radiologists of different expertise evaluated subjective image preference by answering five visual grading analysis-type questions (regarding acceptable level of noise, absence of artifacts, natural appearance, cardiac contour sharpness, diagnostic acceptability) using a 5-point scale. The results were analyzed using visual grade characteristics (VGC) and intraclass correlation coefficient (ICC). RESULTS: Mean SNR in four-chamber view (unfiltered vs. filtered) were: septum=4.1 ± 2.1 versus 7.6 ± 5.6; lateral wall=4.5 ± 2.0 versus 8.0 ± 4.9; CNRseptum=16.6 ± 8.9 versus 31.7 ± 28; lateral wall=16.2 ± 8.9 versus 31.3 ± 28.9. Similar results were obtained in short-axis view. The perceived filtered image quality indicated decreased noise (VGCAUC=0.96) and artifacts (0.65), improved natural appearance (0.59), cardiac contour sharpness (0.74), and diagnostic acceptability (0.78). The inter-observer variability was excellent (ICC=0.79). All results were statistically significant (P < 0.05). CONCLUSION: Similarity filtering after DLR improves image quality, possibly enabling dose reduction in dynamic CTP imaging in patient with suspected chronic coronary syndrome.


Subject(s)
Coronary Artery Disease , Myocardial Perfusion Imaging , Humans , Female , Myocardial Perfusion Imaging/methods , Coronary Artery Disease/diagnostic imaging , Myocardium , Heart/diagnostic imaging , Signal-To-Noise Ratio , Algorithms , Tomography , Radiographic Image Interpretation, Computer-Assisted/methods , Radiation Dosage
9.
Front Cardiovasc Med ; 9: 879139, 2022.
Article in English | MEDLINE | ID: mdl-35879962

ABSTRACT

Introduction: Continuous progress in atrial fibrillation (AF) ablation techniques has led to an increasing number of procedures with improved outcome. However, about 30-50% of patients still experience recurrences within 1 year after their ablation. Comprehensive translational research approaches integrated in clinical care pathways may improve our understanding of the complex pathophysiology of AF and improve patient selection for AF ablation. Objectives: Within the "IntenSive mOlecular and eLectropathological chAracterization of patienTs undergoIng atrial fibrillatiOn ablatioN" (ISOLATION) study, we aim to identify predictors of successful AF ablation in the following domains: (1) clinical factors, (2) AF patterns, (3) anatomical characteristics, (4) electrophysiological characteristics, (5) circulating biomarkers, and (6) genetic background. Herein, the design of the ISOLATION study and the integration of all study procedures into a standardized pathway for patients undergoing AF ablation are described. Methods: ISOLATION (NCT04342312) is a two-center prospective cohort study including 650 patients undergoing AF ablation. Clinical characteristics and routine clinical test results will be collected, as well as results from the following additional diagnostics: determination of body composition, pre-procedural rhythm monitoring, extended surface electrocardiogram, biomarker testing, genetic analysis, and questionnaires. A multimodality model including a combination of established predictors and novel techniques will be developed to predict ablation success. Discussion: In this study, several domains will be examined to identify predictors of successful AF ablation. The results may be used to improve patient selection for invasive AF management and to tailor treatment decisions to individual patients.

10.
Eur Heart J Case Rep ; 6(1): ytab529, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35106443

ABSTRACT

BACKGROUND: Epipericardial fat necrosis (EFN) is a rare cause of chest pain, which is often unrecognized. CASE SUMMARY: A 58-year-old man previously known with a transient ischaemic attack presented with a sharp, substernal chest pain. Pulmonary embolism was ruled out by computed tomography (CT) angiography. However, CT angiography revealed an inhomogeneous epipericardial mass. On cardiovascular magnetic resonance imaging, the mass had an inhomogeneous signal intensity without infiltration of surrounding tissue. Late gadolinium enhancement imaging showed subtle hyperenhancement. Tissue characterization by means of parametric mapping revealed very low native T1 relaxation times and increased T2 relaxation times. In conclusion, the epipericardial mass showed fibrofatty inflammatory markers, suggestive of EFN. The chest pain resolved spontaneously. Follow-up CT 3 months later showed a marked regression of the mass which confirmed the diagnosis EFN. DISCUSSION: Epipericardial fat necrosis is a benign and self-limiting inflammatory cause of chest pain, which can be diagnosed with multi-modality imaging and must not be overlooked in the differential diagnosis of patients with acute pleuritic chest pain.

12.
BMJ Open ; 11(10): e049349, 2021 10 18.
Article in English | MEDLINE | ID: mdl-34663657

ABSTRACT

INTRODUCTION: Current evaluation of patients suspected of a non-ST-elevation acute coronary syndrome (NSTE-ACS) involves the use of algorithms that incorporate clinical information, electrocardiogram (ECG) and high-sensitivity cardiac troponins (hs-troponins). While primarily designed to rule out NSTE-ACS safely, these algorithms can also be used for rule in of NSTE-ACS in some patients. Still, in a substantial number of patients, these algorithms do not provide a conclusive work-up. These patients often present with an atypical clinical profile and low-range positive hs-troponin values without a characteristic rise or fall pattern. They represent a heterogeneous group of patients with various underlying conditions; only a fraction (30%-40%) will eventually be diagnosed with a myocardial infarction. Uncertainty exists about the optimal diagnostic strategy and their management depends on the clinical perspective of the treating physician ranging from direct discharge to admission for invasive coronary angiography. Coronary CT angiography (CCTA) is a non-invasive test that has been shown to be safe, fast and reliable in the evaluation of coronary artery disease. In this study, we will determine the usefulness of CCTA in patients with acute chest pain and low-range positive hs-troponin values. METHODS AND ANALYSIS: A prospective, double-blind, observational, multicentre study conducted in the Netherlands. Patients aged 30-80 years presenting to the emergency department with acute chest pain and a suspicion of NSTE-ACS, a normal or non-diagnostic ECG and low-range positive hs-troponins will be scheduled to undergo CCTA. The primary outcome is the diagnostic accuracy of CCTA for the diagnosis of NSTE-ACS at discharge, in terms of sensitivity and negative predictive value. ETHICS AND DISSEMINATION: This study was approved by the Medical Research Ethics Committee of Erasmus Medical Center in Rotterdam, the Netherlands (registration number MEC-2017-506). Written informed consent to participate will be obtained from all participants. This study's findings will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov (NCT03129659).


Subject(s)
Acute Coronary Syndrome , Troponin , Acute Coronary Syndrome/diagnostic imaging , Biomarkers , Chest Pain/diagnostic imaging , Computed Tomography Angiography , Coronary Angiography , Humans , Multicenter Studies as Topic , Observational Studies as Topic , Prospective Studies , Randomized Controlled Trials as Topic
14.
Open Heart ; 8(1)2021 04.
Article in English | MEDLINE | ID: mdl-33863836

ABSTRACT

Over the past decades, prognosis of patients with cancer has strongly improved and the number of cancer survivors is rapidly growing. Despite this success, cancer treatment is associated with development of serious cardiovascular diseases including left ventricular (LV) systolic dysfunction, heart failure, valvular disease, myocardial infarction, arrhythmias or pericardial diseases. Serial non-invasive cardiac imaging is an important tool to detect early signs of cardiotoxicity, to allow for timely intervention and provide optimal circumstances for long-term prognosis. Currently, echocardiographic imaging is the method of choice for the evaluation of myocardial function during and after cancer therapy. However, 2D echocardiography may fail to detect subtle changes in myocardial function, potentially resulting in a significant delay of therapeutic intervention to impede advanced cardiac disease states with more overt systolic dysfunction. Strain imaging is a promising method for early detection of myocardial dysfunction and may predict future changes in LV ejection fraction. The use of three-dimensional echocardiography may overcome the limitations of 2D echocardiography with more precise and reproducible measurements of LV performance. Cardiac MRI is the gold standard for volumetric assessment and can also be used to perform myocardial tissue characterisation. Visualisation of oedema and fibrosis may provide insights into the degree and disease course of cardiotoxicity and underlying pathophysiological mechanisms. There is growing body of literature regarding the promising role of these advanced imaging modalities in early detection of cardiotoxicity. With this overview paper, new insights and recent results in literature regarding echocardiographic and cardiac magnetic resonance imaging of cancer therapy-related cardiac dysfunction in post-cancer therapy adults will be highlighted.


Subject(s)
Cardiac Imaging Techniques/methods , Cardiomyopathies/diagnosis , Neoplasms/therapy , Stroke Volume/physiology , Ventricular Function, Left/physiology , Cardiomyopathies/physiopathology , Cardiotoxicity , Combined Modality Therapy/adverse effects , Humans
15.
Case Rep Neurol ; 10(2): 118-123, 2018.
Article in English | MEDLINE | ID: mdl-29928217

ABSTRACT

This case report describes a patient who experienced a recurrent ischemic stroke within 24 h. Dual-energy computed tomography (DECT) angiography on admission showed 2 intracardiac thrombi, 1 in the left ventricle and 1 in the left atrial appendage. Following the second ischemic event, repeated DECT angiography showed that the ventricular thrombus had considerably diminished, suggesting that the recurrent brain infarction was caused by cardioembolism. This case emphasizes (1) the potential benefit of cardiac evaluation through CT angiography in the acute stroke setting, and (2) the use of DECT angiography for the detection of thrombus and the differentiation between thrombus, the myocardial wall, and a slow flow of contrast.

16.
MAGMA ; 31(1): 7-18, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29177772

ABSTRACT

OBJECTIVE: To demonstrate imaging performance for cardiac MR imaging at 7 T using a coil array of 8 transmit/receive dipole antennas and 16 receive loops. MATERIALS AND METHODS: An 8-channel dipole array was extended by adding 16 receive-only loops. Average power constraints were determined by electromagnetic simulations. Cine imaging was performed on eight healthy subjects. Geometrical factor (g-factor) maps were calculated to assess acceleration performance. Signal-to-noise ratio (SNR)-scaled images were reconstructed for different combinations of receive channels, to demonstrate the SNR benefits of combining loops and dipoles. RESULTS: The overall image quality of the cardiac functional images was rated a 2.6 on a 4-point scale by two experienced radiologists. Imaging results at different acceleration factors demonstrate that acceleration factors up to 6 could be obtained while keeping the average g-factor below 1.27. SNR maps demonstrate that combining loops and dipoles provides a more than 50% enhancement of the SNR in the heart, compared to a situation where only loops or dipoles are used. CONCLUSION: This work demonstrates the performance of a combined loop/dipole array for cardiac imaging at 7 T. With this array, acceleration factors of 6 are possible without increasing the average g-factor in the heart beyond 1.27. Combining loops and dipoles in receive mode enhances the SNR compared to receiving with loops or dipoles only.


Subject(s)
Cardiac Imaging Techniques/instrumentation , Heart/diagnostic imaging , Magnetic Resonance Imaging/instrumentation , Adult , Cardiac Imaging Techniques/methods , Cardiac Imaging Techniques/statistics & numerical data , Computer Simulation , Electromagnetic Phenomena , Equipment Design , Female , Healthy Volunteers , Humans , Image Enhancement , Magnetic Resonance Imaging/methods , Magnetic Resonance Imaging/statistics & numerical data , Magnetic Resonance Imaging, Cine/instrumentation , Magnetic Resonance Imaging, Cine/methods , Magnetic Resonance Imaging, Cine/statistics & numerical data , Male , Phantoms, Imaging , Signal-To-Noise Ratio , Young Adult
17.
Eur Radiol ; 27(9): 3934-3941, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28271154

ABSTRACT

OBJECTIVES: Relatively little is known about the incidence of long-term renal damage after renal denervation (RDN), a potential new treatment for hypertension. In this study the incidence of renal artery and parenchymal changes, assessed with contrast-enhanced magnetic resonance angiography (MRA) after RDN, is investigated. METHODS: This study is an initiative of ENCOReD, a collaboration of hypertension expert centres. Patients in whom an MRA was performed before and after RDN were included. Scans were evaluated by two independent, blinded radiologists. Primary outcome was the change in renal artery morphology and parenchyma. RESULTS: MRAs from 96 patients were analysed. Before RDN, 41 renal anomalies were observed, of which 29 mostly mild renal artery stenoses. After a median time of 366 days post RDN, MRA showed a new stenosis (25-49% lumen reduction) in two patients and progression of pre-existing lumen reduction in a single patient. No other renal changes were observed and renal function remained stable. CONCLUSIONS: We observed new or progressed renal artery stenosis in three out of 96 patients, after a median time of 12 months post RDN (3.1%). Procedural angiographies showed that ablations were applied near the observed stenosis in only one of the three patients. KEY POINTS: • The incidence of vascular changes 12 months post RDN was 3.1%. • No renal vascular or parenchymal changes other than stenoses were observed. • Ablations were applied near the stenosis in only one of three patients.


Subject(s)
Renal Artery Obstruction/pathology , Renal Artery/pathology , Sympathectomy/adverse effects , Adult , Aged , Aged, 80 and over , Female , Humans , Hypertension, Renovascular/pathology , Hypertension, Renovascular/surgery , Kidney/innervation , Kidney/pathology , Magnetic Resonance Angiography/methods , Male , Middle Aged , Patient Safety , Sympathectomy/methods
18.
Int J Cardiovasc Imaging ; 33(1): 121-128, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27601228

ABSTRACT

Prior to atrial fibrillation (AF) ablation, computed tomography angiography (CTA) is increasingly used for left atrial appendage (LAA) thrombus detection. LAA filling defects on CTA may represent thrombus or incomplete contrast mixing with blood. A pre-bolus of contrast material with delay before the CTA contrast bolus can help distinguish between thrombus and incomplete contrast mixing. We present results from a double-contrast, single-phase CTA protocol used in our daily clinical practice. In patients who underwent AF ablation between 2011 and 2015, double-contrast, single-phase CTA was performed prior to ablation. Two contrast boluses (30 and 70 ml) with 25-s interbolus delay were administered followed by prospectively triggered cardiac CTA. Only patients with left atrial (LA) or LAA filling defects underwent transesophageal echocardiography (TEE) to rule out thrombus. Prior to ablation, 605 CTA-scans were performed (median radiation dose: 3.1 mSv). In 579 CTA-scans (95.7 %), the LA and LAA completely filled with contrast. In 26 CTA-scans (4.3 %) the LAA showed a filling defect whereby thrombus could not be excluded. In 2 of those 26 patients (7.7 % and 0.3 % of the total population), TEE verified LAA thrombus. Low-risk LAA filling defects on CTA (n = 7/26) with an inhomogeneous aspect, Houndsfield Unit values >100, and an indefinite border were all caused by incomplete contrast mixing. No thromboembolic complications occurred perioperatively or during 6 months follow-up. Prior to AF ablation, incidence of LAA filling defects on double-contrast, single-phase CTA is low. TEE remains warranted in all but low-risk filling defects to rule out thrombus.


Subject(s)
Atrial Appendage/diagnostic imaging , Atrial Fibrillation/diagnostic imaging , Computed Tomography Angiography , Contrast Media/administration & dosage , Coronary Angiography/methods , Multidetector Computed Tomography , Thrombosis/diagnostic imaging , Aged , Atrial Appendage/physiopathology , Atrial Appendage/surgery , Atrial Fibrillation/complications , Atrial Fibrillation/physiopathology , Atrial Fibrillation/surgery , Catheter Ablation , Echocardiography, Doppler, Pulsed , Echocardiography, Transesophageal , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Retrospective Studies , Thrombosis/etiology , Thrombosis/physiopathology
19.
J Cardiovasc Comput Tomogr ; 10(5): 398-406, 2016.
Article in English | MEDLINE | ID: mdl-27452311

ABSTRACT

BACKGROUND: In patients with suspected prosthetic heart valve (PHV) dysfunction, routine evaluation echocardiography and fluoroscopy may provide unsatisfactory results for identifying the cause of dysfunction. This study assessed the value of MDCT as a routine, complementary imaging modality in suspected PHV-dysfunction for diagnosing the cause of PHV dysfunction and proposing a treatment strategy. METHODS: Patients with suspected PHV dysfunction were prospectively recruited. All patients underwent routine diagnostic work-up (TTE, TEE ± fluoroscopy) and additional MDCT imaging. An expert panel reviewed all cases and assessed the diagnosis and treatment strategy, first based on routine evaluation only, second with additional MDCT information. RESULTS: Forty-two patients were included with suspected PHV obstruction (n = 30) and PHV regurgitation (n = 12). The addition of MDCT showed incremental value to routine evaluation in 26/30 (87%) cases for detecting the specific cause of PHV obstruction and in 7/12 (58%) regurgitation cases for assessment of complications and surgical planning. The addition of MDCT resulted in treatment strategy change in 8/30 (27%) patients with suspected obstruction and 3/12 (25%) patients with regurgitation. CONCLUSION: In addition to echocardiography and fluoroscopy, MDCT may identify the cause of PHV dysfunction and alter the treatment strategy.


Subject(s)
Aortic Valve/surgery , Heart Valve Prosthesis Implantation/instrumentation , Heart Valve Prosthesis , Mitral Valve/surgery , Multidetector Computed Tomography , Prosthesis Failure , Adult , Aged , Aortic Valve/diagnostic imaging , Aortic Valve/physiopathology , Cardiac-Gated Imaging Techniques , Cross-Sectional Studies , Echocardiography, Doppler, Color , Electrocardiography , Female , Heart Valve Prosthesis Implantation/adverse effects , Hemodynamics , Humans , Male , Middle Aged , Mitral Valve/diagnostic imaging , Mitral Valve/physiopathology , Netherlands , Predictive Value of Tests , Prospective Studies , Reoperation , Risk Factors , Treatment Outcome
20.
Eur Radiol ; 26(11): 3771-3780, 2016 Nov.
Article in English | MEDLINE | ID: mdl-26847041

ABSTRACT

OBJECTIVES: To provide a comprehensive overview of all reported cardiac magnetic resonance (CMR) findings that predict clinical deterioration in pulmonary arterial hypertension (PAH). METHODS: MEDLINE and EMBASE electronic databases were systematically searched for longitudinal studies published by April 2015 that reported associations between CMR findings and adverse clinical outcome in PAH. Studies were appraised using previously developed criteria for prognostic studies. Meta-analysis using random effect models was performed for CMR findings investigated by three or more studies. RESULTS: Eight papers (539 patients) investigating 21 different CMR findings were included. Meta-analysis showed that right ventricular (RV) ejection fraction was the strongest predictor of mortality in PAH (pooled HR 1.23 [95 % CI 1.07-1.41], p = 0.003) per 5 % decrease. In addition, RV end-diastolic volume index (pooled HR 1.06 [95 % CI 1.00-1.12], p = 0.049), RV end-systolic volume index (pooled HR 1.05 [95 % CI 1.01-1.09], p = 0.013) and left ventricular end-diastolic volume index (pooled HR 1.16 [95 % CI 1.00-1.34], p = 0.045) were of prognostic importance. RV and LV mass did not provide prognostic information (p = 0.852 and p = 0.983, respectively). CONCLUSION: This meta-analysis substantiates the clinical yield of specific CMR findings in the prognostication of PAH patients. Decreased RV ejection is the strongest and most well established predictor of mortality. KEY POINTS: • Cardiac magnetic resonance imaging is useful for prognostication in pulmonary arterial hypertension. • Right ventricular ejection fraction is the strongest predictor of mortality. • Serial CMR evaluation seems to be of additional prognostic importance. • Accurate prognostication can aid in adequate and timely intensification of PAH-specific therapy.


Subject(s)
Hypertension, Pulmonary/diagnosis , Magnetic Resonance Imaging, Cine/methods , Ventricular Dysfunction, Right/diagnosis , Ventricular Function, Right/physiology , Humans , Hypertension, Pulmonary/complications , Hypertension, Pulmonary/physiopathology , Prognosis , Stroke Volume , Ventricular Dysfunction, Right/etiology , Ventricular Dysfunction, Right/physiopathology
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