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BACKGROUND: High-fidelity cardiac magnetic resonance (MR) imaging plays a pivotal role in the surveillance of congenital heart disease (CHD) and aortopathy. OBJECTIVE: We aimed to evaluate the quality and accuracy of free breathing, ECG-gated noncontrast three-dimensional (3D) balanced steady-state free precession (bSSFP) in cases of CHDs and aortopathies using contrast-enhanced 3D bSSFP as a reference. We also used one of our routinely used non-ECG-gated 2D-single-shot (SSh) bSSFP sequence as an adjunct to noncontrast 3D bSSFP. MATERIALS AND METHODS: Institutional review board approval was obtained to perform a systematic retrospective analysis of image quality and vascular measurements. Patients with CHD and aortopathy, who were undergoing clinically indicated contrast-enhanced 3D bSSFP, were prospectively identified to also undergo additional noncontrast 3D bSSFP and 2D SSh bSSFP imaging as part of a clinical quality improvement initiative aimed at reducing the use of contrast when feasible. Two readers, blinded to each other's evaluations, graded image quality on a 5-point Likert scale and performed vascular measurements in separate sessions for both 3D bSSFP images. They also reported the visibility of various mediastinal great vessels on 2D SSh bSSFP images. Raw agreement, the weighted kappa statistic, and intra-class correlation coefficients (ICCs) were computed to assess the consistency and agreement between the two readers. Comparative analysis of noncontrast and contrast-enhanced 3D bSSFP imaging was performed in adult and pediatric patients using a two-sided paired t-test and Bland-Altman analysis. A P-value < 0.05 was considered significant for all inference testing. RESULTS: A total of 29 patients (17 males, median age 20.3 years, interquartile range (IQR) 12.5, age range 7-39 years), including 11 pediatric patients under the age of 18 years (6 males, median age 14.5 years, IQR 4.0, age range 7-17 years), underwent retrospective analysis. The overall image quality score for contrast-enhanced 3D bSSFP was significantly higher (P < 0.0001) than that of noncontrast 3D bSSFP for both all subjects (4.4 ± 0.2, range 4.0-4.9 vs 3.7 ± 0.4, range 3.1-4.7) and only pediatric subjects (4.3 ± 0.3, range 4.0-4.9 vs 3.6 ± 0.5, range 3.1-4.4). By combining noncontrast 3D bSSFP and 2D bSSFP, reader 1 and reader 2 rated 423 and 420 vessels diagnostic, respectively, in a total of 435 vessel segments. All landmarks showed similar mean vessel diameters without significant differences between noncontrast and contrast-enhanced 3D bSSFP MR angiography (r = 0.99, bias -0.31 mm, 95% limits of agreement -2.04 mm to 1.43 mm). CONCLUSIONS: Although contrast-enhanced images had better overall image quality, an imaging protocol consisting of noncontrast 2D SSh bSSFP and 3D bSSFP whole-chest images provides diagnostically adequate image quality, and accurate vascular measurements, comparable to free-breathing contrast-enhanced 3D bSSFP in both children and adults with CHD and aortopathies.
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Enfermedades de la Aorta , Técnicas de Imagen Sincronizada Cardíacas , Cardiopatías Congénitas , Imagenología Tridimensional , Humanos , Cardiopatías Congénitas/diagnóstico por imagen , Imagenología Tridimensional/métodos , Masculino , Niño , Femenino , Adolescente , Técnicas de Imagen Sincronizada Cardíacas/métodos , Enfermedades de la Aorta/diagnóstico por imagen , Reproducibilidad de los Resultados , Adulto , Estudios Retrospectivos , Preescolar , Electrocardiografía/métodos , Medios de Contraste , Sensibilidad y Especificidad , Lactante , Adulto Joven , Interpretación de Imagen Asistida por Computador/métodos , Aumento de la Imagen/métodosRESUMEN
OBJECTIVE: Aortic Dissection (AD) is one of the most fatal acute diseases in cardiovascular diseases, with rapid onset and progression and a high fatality rate. This study aims to investigate the clinical values of non-enhancement peripheral pulse-gating rapid magnetic resonance imaging in deterministic diagnosis of AD. METHODS: Aorta magnetic resonance imaging was performed in 21 healthy volunteers at a 1.5t MR scanner sequences including cardiac-gated and peripheral pulse-gated True-FISP and HASTE were carried out separately. Acquisition Time (TA), Signal to Noise Ratio (SNR), Contrast Noise Ratio (CNR), and entirety of vessel wall blood flow artifacts were measured and compared. A total of 56 AD cases were displayed by non-enhancement peripheral pulse-gating fast MR imaging, and the results were compared with pathological findings or CTA of the aorta. The dissection rupture, tear film, true and false lumen, thrombosis, hydropericardium, and the main branches of AD were evaluated respectively. RESULTS: There were no significant differences in SNR, CNR, entirety of the vessel wall, and blood flow artifact between cardiac-gated and peripheral pulse-gated fast MR imaging. Non-enhancement pulse-gated fast scanning takes less TA time. By the pulse-gated non-enhancement fast MR imaging, the dissection rupture, tear film, true and false cavity, thrombosis, hydropericardium, and the main branches of aortic dissection were shown clearly. Multi-planar and multi-angle scans helped to show the extent of entrapment rupture, whereas partial complex tears or bi-directional tears were slightly less well visualized. CONCLUSION: Non-enhancement peripheral pulse-gated rapid magnetic resonance imaging can be used for deterministic diagnosis of AD.
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Disección Aórtica , Imagen por Resonancia Magnética , Humanos , Disección Aórtica/diagnóstico por imagen , Masculino , Femenino , Adulto , Persona de Mediana Edad , Imagen por Resonancia Magnética/métodos , Relación Señal-Ruido , Aneurisma de la Aorta/diagnóstico por imagen , Anciano , Reproducibilidad de los Resultados , Adulto Joven , Técnicas de Imagen Sincronizada Cardíacas/métodos , Valores de ReferenciaRESUMEN
PURPOSE: In planning transcatheter aortic valve replacement (TAVR), retrospective cardiac spiral-CT is recommended to measure aortic annulus with subsequent CT-angiography (CTA) to evaluate access routes. Photon-counting detector (PCD)-CT enables to assess the aortic annulus in desired cardiac phases, using prospective ECG-gated high-pitch CTA. The aim of this study was to evaluate the measurement accuracy of aortic annulus using prospective ECG-gated high-pitch CTA against retrospective spiral-CT reference. METHOD: Thirty patients underwent cardiac spiral-CT and prospective ECG-gated (30% R-R on aortic valve level) high-pitch CTA. Using propensity score matching, another 30 patients were identified whose CTA was performed using high-pitch mode without ECG-synchronization. Two investigators measured annular diameter, perimeter, and area on cardiac spiral-CT and high-pitch CTA. RESULTS: The aortic valve was imaged in systole in 90 % of prospective ECG-gated CTA cases but only 50 % of non-ECG-gated CTA cases (p = 0.002). There was a strong correlation (r ≥ 0.94) without significant differences (p ≥ 0.09) between cardiac spiral-CT and prospective ECG-gated high-pitch CTA for all annulus measurements. In contrast, significant differences were found in annular short-axis diameter and area between cardiac spiral-CT and non-ECG-gated high-pitch CTA (p ≤ 0.03). Furthermore, prospective ECG-gated high-pitch CTA showed significantly reduced radiation exposure compared with cardiac spiral-CT (CTDI 4.52 vs. 24.10 mGy; p < 0.001). CONCLUSION: PCD-CT-based prospective ECG-gated high-pitch scans with targeted systolic acquisition at the level of the aortic valve can simultaneously visualize TAVR access routes and accurately measure systolic annulus size. This approach could aid in optimizing protocols to achieve lower radiation doses in the growing population of younger, low-risk TAVR patients.
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Válvula Aórtica , Técnicas de Imagen Sincronizada Cardíacas , Angiografía por Tomografía Computarizada , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Reemplazo de la Válvula Aórtica Transcatéter/métodos , Masculino , Femenino , Angiografía por Tomografía Computarizada/métodos , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Anciano de 80 o más Años , Anciano , Reproducibilidad de los Resultados , Estudios Prospectivos , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugía , Electrocardiografía , FotonesRESUMEN
Objective.This study explores the feasibility of a stationary gantry cardiac gated computed tomography (CT) with carbon nanotube (CNT) linear x-ray source arrays.Approach.We developed a stationary gantry CT system utilizing multipixel CNT x-ray sources. Given the advantages of straightforward x-ray pulse control with these sources, we investigated the potential for gated prospective imaging. We implemented prospective respiratory and cardiac gating control and evaluated the system through dynamic phantom imaging studies followed by imaging of a porcine model.Main Results.The findings revealed minimal anatomical motion artifacts in the heart and lungs, confirming successful physiologic gated acquisition in stationary gantry cardiac CT. This indicates the potential of this imaging approach for reducing artifacts and improving image quality.Significance.This study demonstrates the feasibility of prospective physiological gating with CNT x-ray sources in a stationary gantry setup for cardiac imaging. This approach could potentially alleviate the need for beta blocker administration during cardiac CT scans, thereby increasing the flexibility of the imaging system and enabling the imaging of a wider variety of patient cardiac conditions.
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Corazón , Nanotubos de Carbono , Fantasmas de Imagen , Tomografía Computarizada por Rayos X , Animales , Porcinos , Corazón/diagnóstico por imagen , Tomografía Computarizada por Rayos X/instrumentación , Técnicas de Imagen Sincronizada Cardíacas/métodos , Estudios Prospectivos , Estudios de Factibilidad , ArtefactosRESUMEN
OBJECTIVE: Dynamic Ultrasound Localization Microscopy (DULM) has first been developed for non-invasive Pulsatility measurements in the rodent brain. DULM relies on the localization and tracking of microbubbles (MBs) injected into the bloodstream, to obtain highly resolved velocity and density cine-loops. Previous DULM techniques required ECG-gating, limiting its application to specific datasets, and increasing acquisition time. The objective of this study is to eliminate the need for ECG-gating in DULM experiments by introducing a motion-matching method for time registration. METHODS: We developed a motion-matching algorithm based on tissue Doppler that leverages the cyclic tissue motion within the brain. Tissue Doppler was estimated for each group of frames in the acquisitions, at multiple locations identified as local maxima in the skin above the skull. Subsequently, each group of frames was time-registered to a reference group by delaying it based on the maximum correlation value between their respective tissue Doppler signals. This synchronization ensured that each group of frames aligned with the brain tissue motion of the reference group, and consequently, with its cardiac cycle. As a result, velocities of MBs could be averaged to retrieve flow velocity variations over time. RESULTS: Initially validated in ECG-gated acquisitions in a rat model (n = 1), the proposed method was successfully applied in a mice model in 2D (n = 3) and in a feline model in 3D (n = 1). Performing time-registration with the proposed motion-matching method or by using ECG-gating leads to similar results. For the first time, dynamic velocity and density cine-loops were extracted without the need for any information on the animal ECG, and complex dynamic markers such as the Pulsatility index were estimated. CONCLUSION: Results suggest that DULM can be performed without external gating, enabling the use of DULM on any ULM dataset where enough MBs are detectable. Time registration by motion-matching represents a significant advancement in DULM techniques, making DULM more accessible by simplifying its experimental complexity.
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Microburbujas , Animales , Ratas , Encéfalo/diagnóstico por imagen , Algoritmos , Microscopía/métodos , Ratones , Electrocardiografía/métodos , Técnicas de Imagen Sincronizada Cardíacas/métodosRESUMEN
BACKGROUND: Cardiac positron emission tomography (PET) can visualize and quantify the molecular and physiological pathways of cardiac function. However, cardiac and respiratory motion can introduce blurring that reduces PET image quality and quantitative accuracy. Dual cardiac- and respiratory-gated PET reconstruction can mitigate motion artifacts but increases noise as only a subset of data are used for each time frame of the cardiac cycle. AIM: The objective of this study is to create a zero-shot image denoising framework using a conditional generative adversarial networks (cGANs) for improving image quality and quantitative accuracy in non-gated and dual-gated cardiac PET images. METHODS: Our study included retrospective list-mode data from 40 patients who underwent an 18F-fluorodeoxyglucose (18F-FDG) cardiac PET study. We initially trained and evaluated a 3D cGAN-known as Pix2Pix-on simulated non-gated low-count PET data paired with corresponding full-count target data, and then deployed the model on an unseen test set acquired on the same PET/CT system including both non-gated and dual-gated PET data. RESULTS: Quantitative analysis demonstrated that the 3D Pix2Pix network architecture achieved significantly (p value<0.05) enhanced image quality and accuracy in both non-gated and gated cardiac PET images. At 5%, 10%, and 15% preserved count statistics, the model increased peak signal-to-noise ratio (PSNR) by 33.7%, 21.2%, and 15.5%, structural similarity index (SSIM) by 7.1%, 3.3%, and 2.2%, and reduced mean absolute error (MAE) by 61.4%, 54.3%, and 49.7%, respectively. When tested on dual-gated PET data, the model consistently reduced noise, irrespective of cardiac/respiratory motion phases, while maintaining image resolution and accuracy. Significant improvements were observed across all gates, including a 34.7% increase in PSNR, a 7.8% improvement in SSIM, and a 60.3% reduction in MAE. CONCLUSION: The findings of this study indicate that dual-gated cardiac PET images, which often have post-reconstruction artifacts potentially affecting diagnostic performance, can be effectively improved using a generative pre-trained denoising network.
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Corazón , Procesamiento de Imagen Asistido por Computador , Tomografía de Emisión de Positrones , Relación Señal-Ruido , Humanos , Corazón/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Tomografía de Emisión de Positrones/métodos , Estudios Retrospectivos , Fluorodesoxiglucosa F18 , Masculino , Femenino , Técnicas de Imagen Sincronizada Cardíacas/métodos , Artefactos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Persona de Mediana EdadRESUMEN
To assess the diagnostic performance of unenhanced electrocardiogram (ECG)-gated cardiac computed tomography (CT) for detecting myocardial edema, using MRI T2 mapping as the reference standard. This retrospective study protocol was approved by our institutional review board, which waived the requirement for written informed consent. Between December 2017 to February 2019, consecutive patients who had undergone T2 mapping for myocardial tissue characterization were identified. We excluded patients who did not undergo unenhanced ECG-gated cardiac CT within 3 months from MRI T2 mapping or who had poor CT image quality. All patients underwent unenhanced ECG-gated cardiac CT with an axial scan using a third-generation, 320â ×â 0.5 mm detector-row CT unit. Two radiologists together drew regions of interest (ROIs) in the interventricular septum on the unenhanced ECG-gated cardiac CT images. Using T2 mapping as the reference standard, the diagnostic performance of unenhanced cardiac CT for detecting myocardial edema was evaluated by using the area under the receiver operating characteristic curve with sensitivity and specificity. Youden index was used to find an optimal sensitivity-specificity cutoff point. A cardiovascular radiologist independently performed the measurements, and interobserver reliability was assessed using intraclass correlation coefficients for CT value measurements. A P value of <.05 was considered statistically significant. We included 257 patients who had undergone MRI T2 mapping. Of the 257 patients, 35 patients underwent unenhanced ECG-gated cardiac CT. One patient was excluded from the study because of poor CT image quality. Finally, 34 patients (23 men; age 64.7â ±â 14.6 years) comprised our study group. Using T2 mapping, we identified myocardial edema in 19 patients. Mean CT and T2 values for 34 patients were 46.3â ±â 2.7 Hounsfield unit and 49.0â ±â 4.9 ms, respectively. Mean CT values moderately correlated with mean T2 values (Rhoâ =â -0.41; Pâ <â .05). Mean CT values provided a sensitivity of 63.2% and a specificity of 93.3% for detecting myocardial edema, with a cutoff value of ≤45.0 Hounsfield unit (area under the receiver operating characteristic curveâ =â 0.77; Pâ <â .01). Inter-observer reproducibility in measuring mean CT values was excellent (intraclass correlation coefficientâ =â 0.93; [95% confidence interval: 0.86, 0.96]). Myocardial edema could be detected by CT value of myocardium in unenhanced ECG-gated cardiac CT.
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Electrocardiografía , Tomografía Computarizada por Rayos X , Humanos , Masculino , Femenino , Persona de Mediana Edad , Estudios Retrospectivos , Electrocardiografía/métodos , Tomografía Computarizada por Rayos X/métodos , Anciano , Imagen por Resonancia Magnética/métodos , Sensibilidad y Especificidad , Reproducibilidad de los Resultados , Edema/diagnóstico por imagen , Edema Cardíaco/diagnóstico por imagen , Técnicas de Imagen Sincronizada Cardíacas/métodos , Curva ROC , AdultoRESUMEN
To assess the impact of low-dose contrast media (CM) injection protocol with deep learning image reconstruction (DLIR) algorithm on image quality in coronary CT angiography (CCTA). In this prospective study, patients underwent CCTA were prospectively and randomly assigned to three groups with different contrast volume protocols (at 320mgI/mL concentration and constant flow rate of 5ml/s). After pairing basic information, 210 patients were enrolled in this study: Group A, 0.7mL/kg (n = 70); Group B, 0.6mL/kg (n = 70); Group C, 0.5mL/kg (n = 70). All patients were examined via a prospective ECG-triggered scan protocol within one heartbeat. A high level DLIR (DLIR-H) algorithm was used for image reconstruction with a thickness and interval of 0.625mm. The CT values of ascending aorta (AA), descending aorta (DA), three main coronary arteries, pulmonary artery (PA), and superior vena cava (SVC) were measured and analyzed for objective assessment. Two radiologists assessed the image quality and diagnostic confidence using a 5-point Likert scale. The CM doses were 46.81 ± 6.41mL, 41.96 ± 7.51mL and 34.65 ± 5.38mL for Group A, B and C, respectively. The objective assessments on AA, DA and the three main coronary arteries and the overall subjective scoring showed no significant difference among the three groups (all p > 0.05). The subjective assessment proved that excellent CCTA images can be obtained from the three different contrast media protocols. There were no significant differences in intracoronary attenuation values between the higher HR subgroup and the lower HR subgroup among three groups. CCTA reconstructed with DLIR could be realized with adequate enhancement in coronary arteries, excellent image quality and diagnostic confidence at low contrast dose of a 0.5mL/kg. The use of lower tube voltages may further reduce the contrast dose requirement.
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Técnicas de Imagen Sincronizada Cardíacas , Angiografía por Tomografía Computarizada , Medios de Contraste , Angiografía Coronaria , Enfermedad de la Arteria Coronaria , Vasos Coronarios , Aprendizaje Profundo , Electrocardiografía , Valor Predictivo de las Pruebas , Interpretación de Imagen Radiográfica Asistida por Computador , Humanos , Angiografía Coronaria/métodos , Estudios Prospectivos , Medios de Contraste/administración & dosificación , Masculino , Femenino , Persona de Mediana Edad , Anciano , Vasos Coronarios/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/fisiopatología , Reproducibilidad de los Resultados , Frecuencia Cardíaca , Dosis de Radiación , Tomografía Computarizada MultidetectorRESUMEN
Almost 35 years after its introduction, coronary artery calcium score (CACS) not only survived technological advances but became one of the cornerstones of contemporary cardiovascular imaging. Its simplicity and quantitative nature established it as one of the most robust approaches for atherosclerotic cardiovascular disease risk stratification in primary prevention and a powerful tool to guide therapeutic choices. Groundbreaking advances in computational models and computer power translated into a surge of artificial intelligence (AI)-based approaches directly or indirectly linked to CACS analysis. This review aims to provide essential knowledge on the AI-based techniques currently applied to CACS, setting the stage for a holistic analysis of the use of these techniques in coronary artery calcium imaging. While the focus of the review will be detailing the evidence, strengths, and limitations of end-to-end CACS algorithms in electrocardiography-gated and non-gated scans, the current role of deep-learning image reconstructions, segmentation techniques, and combined applications such as simultaneous coronary artery calcium and pulmonary nodule segmentation, will also be discussed.
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Angiografía Coronaria , Enfermedad de la Arteria Coronaria , Vasos Coronarios , Aprendizaje Profundo , Valor Predictivo de las Pruebas , Interpretación de Imagen Radiográfica Asistida por Computador , Calcificación Vascular , Humanos , Calcificación Vascular/diagnóstico por imagen , Calcificación Vascular/terapia , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/terapia , Vasos Coronarios/diagnóstico por imagen , Pronóstico , Angiografía por Tomografía Computarizada , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Inteligencia Artificial , Técnicas de Imagen Sincronizada CardíacasRESUMEN
This study compared the prognostic value of quantified thoracic artery calcium (TAC) including aortic arch on chest CT and coronary artery calcium (CAC) score on ECG-gated cardiac CT. METHODS: A total of 2412 participants who underwent both chest CT and ECG-gated cardiac CT at the same period were included in the Multi-Ethnic Study of Atherosclerosis Exam 5. All participants were monitored for incident atherosclerotic cardiovascular disease (ASCVD) events. TAC is defined as calcification in the ascending aorta, aortic arch and descending aorta on chest CT. The quantification of TAC was measured using the Agatston method. Time-dependent receiver-operating characteristic (ROC) curves were used to compare the prognostic value of TAC and CAC scores. RESULTS: Participants were 69±9 years of age and 47% were male. The Spearman correlation between TAC and CAC scores was 0.46 (p<0.001). During the median follow-up period of 8.8 years, 234 participants (9.7%) experienced ASCVD events. In multivariable Cox regression analysis, TAC score was independently associated with increased risk of ASCVD events (HR 1.31, 95% CI 1.09 to 1.58) as well as CAC score (HR 1.82, 95% CI 1.53 to 2.17). However, the area under the time-dependent ROC curve for CAC score was greater than that for TAC score in all participants (0.698 and 0.641, p=0.031). This was particularly pronounced in participants with borderline/intermediate and high 10-year ASCVD risk scores. CONCLUSION: Our study demonstrated a significant association between TAC and CAC scores but a superior prognostic value of CAC score for ASCVD events. These findings suggest TAC on chest CT provides supplementary data to estimate ASCVD risk but does not replace CAC on ECG-gated cardiac CT.
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Enfermedad de la Arteria Coronaria , Calcificación Vascular , Humanos , Masculino , Femenino , Anciano , Calcificación Vascular/diagnóstico por imagen , Calcificación Vascular/epidemiología , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/epidemiología , Enfermedad de la Arteria Coronaria/diagnóstico , Pronóstico , Persona de Mediana Edad , Medición de Riesgo/métodos , Angiografía por Tomografía Computarizada , Valor Predictivo de las Pruebas , Aorta Torácica/diagnóstico por imagen , Factores de Riesgo , Enfermedades de la Aorta/diagnóstico por imagen , Enfermedades de la Aorta/epidemiología , Enfermedades de la Aorta/diagnóstico , Curva ROC , Vasos Coronarios/diagnóstico por imagen , Técnicas de Imagen Sincronizada Cardíacas , Estados Unidos/epidemiología , Electrocardiografía , Incidencia , Angiografía Coronaria/métodos , Tomografía Computarizada por Rayos X , Aterosclerosis/epidemiología , Aterosclerosis/diagnósticoRESUMEN
Objective.In cardiovascular magnetic resonance imaging, synchronization of image acquisition with heart motion (calledgating) is performed by detecting R-peaks in electrocardiogram (ECG) signals. Effective gating is challenging with 3T and 7T scanners, due to severe distortion of ECG signals caused by magnetohydrodynamic effects associated with intense magnetic fields. This work proposes an efficient retrospective gating strategy that requires no prior training outside the scanner and investigates the optimal number of leads in the ECG acquisition set.Approach.The proposed method was developed on a data set of 12-lead ECG signals acquired within 3T and 7T scanners. Independent component analysis is employed to effectively separate components related with cardiac activity from those associated to noise. Subsequently, an automatic selection process identifies the components best suited for accurate R-peak detection, based on heart rate estimation metrics and frequency content quality indexes.Main results.The proposed method is robust to different B0 field strengths, as evidenced by R-peak detection errors of 2.4 ± 3.1 ms and 10.6 ± 15.4 ms for data acquired with 3T and 7T scanners, respectively. Its effectiveness was verified with various subject orientations, showcasing applicability in diverse clinical scenarios. The work reveals that ECG leads can be limited in number to three, or at most five for 7T field strengths, without significant degradation in R-peak detection accuracy.Significance.The approach requires no preliminary ECG acquisition for R-peak detector training, reducing overall examination time. The gating process is designed to be adaptable, completely blind and independent of patient characteristics, allowing wide and rapid deployment in clinical practice. The potential to employ a significantly limited set of leads enhances patient comfort.
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Electrocardiografía , Corazón , Imagen por Resonancia Magnética , Humanos , Imagen por Resonancia Magnética/métodos , Corazón/diagnóstico por imagen , Corazón/fisiología , Procesamiento de Imagen Asistido por Computador/métodos , Procesamiento de Señales Asistido por Computador , Masculino , Adulto , Frecuencia Cardíaca , Técnicas de Imagen Sincronizada Cardíacas/métodos , Femenino , Estudios RetrospectivosRESUMEN
BACKGROUND: LV geometry with shape index (SI) and eccentricity index (EI) measured by myocardial perfusion positron emission tomography/computed tomography (PET/CT) may allow the evaluation of left ventricular (LV) adverse remodeling. This first study aims to explore the relationship of SI and EI values acquired by Nitrogen-13 ammonia PET/CT in patients with normal perfusion, ischemia, and myocardial infarction. And evaluate the correlations between the variables of LV geometry, and with the variables of LV function. METHODS AND RESULTS: One hundred and forty patients who underwent an electrocardiogram (ECG)-gated PET/CT were selected and classified into 4 groups according to ischemia or infarction burden (normal perfusion, mild ischemia, moderate-severe ischemia, and infarction). The variables were automatically retrieved using dedicated software (QPS/QGS; Cedars-Sinai, Los Angeles, CA, USA). On multicomparison analysis (one-way ANOVA and Dunnett's Test), subjects in the infarction group had significant higher values of SI end-diastolic rest (P < 0.001), and stress (P = 0.003), SI end-systolic rest (P = 0.002) and stress (P < 0.001) as well as statistically significant lower values of EI rest (P < 0.001) and stress (P < 0.001) when compared with all other groups. Regarding Pearson correlation, in the infarcted group all the variables of SI and EI were significantly correlated (P < 0.001) with strong correlation coefficients (>0.60). SI end-systolic correlated significantly with the variables of LV function independently of the group of patients (P < 0.05). CONCLUSIONS: Shape and eccentricity indices differ in patients with myocardial infarction as compared to patients with ischemia or normal perfusion. This encourage further research in their potential for detecting LV adverse remodeling.
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Amoníaco , Electrocardiografía , Ventrículos Cardíacos , Infarto del Miocardio , Isquemia Miocárdica , Imagen de Perfusión Miocárdica , Radioisótopos de Nitrógeno , Tomografía Computarizada por Tomografía de Emisión de Positrones , Humanos , Masculino , Femenino , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/fisiopatología , Persona de Mediana Edad , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Anciano , Imagen de Perfusión Miocárdica/métodos , Ventrículos Cardíacos/diagnóstico por imagen , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/fisiopatología , Radiofármacos , Técnicas de Imagen Sincronizada Cardíacas , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/fisiopatología , Reproducibilidad de los ResultadosRESUMEN
Contrast enhanced pulmonary vein magnetic resonance angiography (PV CE-MRA) has value in atrial ablation pre-procedural planning. We aimed to provide high fidelity, ECG gated PV CE-MRA accelerated by variable density Cartesian sampling (VD-CASPR) with image navigator (iNAV) respiratory motion correction acquired in under 4 min. We describe its use in part during the global iodinated contrast shortage. VD-CASPR/iNAV framework was applied to ECG-gated inversion and saturation recovery gradient recalled echo PV CE-MRA in 65 patients (66 exams) using .15 mmol/kg Gadobutrol. Image quality was assessed by three physicians, and anatomical segmentation quality by two technologists. Left atrial SNR and left atrial/myocardial CNR were measured. 12 patients had CTA within 6 months of MRA. Two readers assessed PV ostial measurements versus CTA for intermodality/interobserver agreement. Inter-rater/intermodality reliability, reproducibility of ostial measurements, SNR/CNR, image, and anatomical segmentation quality was compared. The mean acquisition time was 3.58 ± 0.60 min. Of 35 PV pre-ablation datasets (34 patients), mean anatomical segmentation quality score was 3.66 ± 0.54 and 3.63 ± 0.55 as rated by technologists 1 and 2, respectively (p = 0.7113). Good/excellent anatomical segmentation quality (grade 3/4) was seen in 97% of exams. Each rated one exam as moderate quality (grade 2). 95% received a majority image quality score of good/excellent by three physicians. Ostial PV measurements correlated moderate to excellently with CTA (ICCs range 0.52-0.86). No difference in SNR was observed between IR and SR. High quality PV CE-MRA is possible in under 4 min using iNAV bolus timing/motion correction and VD-CASPR.
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Medios de Contraste , Interpretación de Imagen Asistida por Computador , Angiografía por Resonancia Magnética , Variaciones Dependientes del Observador , Compuestos Organometálicos , Valor Predictivo de las Pruebas , Venas Pulmonares , Humanos , Venas Pulmonares/diagnóstico por imagen , Venas Pulmonares/cirugía , Venas Pulmonares/fisiopatología , Masculino , Femenino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Medios de Contraste/administración & dosificación , Compuestos Organometálicos/administración & dosificación , Anciano , Técnicas de Imagen Sincronizada Cardíacas , Fibrilación Atrial/cirugía , Fibrilación Atrial/diagnóstico por imagen , Fibrilación Atrial/fisiopatología , Ablación por Catéter , ElectrocardiografíaRESUMEN
BACKGROUND: ECG-gated cardiac CT is now widely used in infants with congenital heart disease (CHD). Deep Learning Image Reconstruction (DLIR) could improve image quality while minimizing the radiation dose. OBJECTIVES: To define the potential dose reduction using DLIR with an anthropomorphic phantom. METHOD: An anthropomorphic pediatric phantom was scanned with an ECG-gated cardiac CT at four dose levels. Images were reconstructed with an iterative and a deep-learning reconstruction algorithm (ASIR-V and DLIR). Detectability of high-contrast vessels were computed using a mathematical observer. Discrimination between two vessels was assessed by measuring the CT spatial resolution. The potential dose reduction while keeping a similar level of image quality was assessed. RESULTS: DLIR-H enhances detectability by 2.4% and discrimination performances by 20.9% in comparison with ASIR-V 50. To maintain a similar level of detection, the dose could be reduced by 64% using high-strength DLIR in comparison with ASIR-V50. CONCLUSION: DLIR offers the potential for a substantial dose reduction while preserving image quality compared to ASIR-V.
Asunto(s)
Técnicas de Imagen Sincronizada Cardíacas , Aprendizaje Profundo , Cardiopatías Congénitas , Fantasmas de Imagen , Valor Predictivo de las Pruebas , Dosis de Radiación , Exposición a la Radiación , Interpretación de Imagen Radiográfica Asistida por Computador , Humanos , Lactante , Exposición a la Radiación/prevención & control , Cardiopatías Congénitas/diagnóstico por imagen , Reproducibilidad de los Resultados , Electrocardiografía , Angiografía Coronaria/métodos , Angiografía por Tomografía Computarizada , Factores de EdadAsunto(s)
Angiografía por Tomografía Computarizada , Angiografía Coronaria , Enfermedad de la Arteria Coronaria , Valor Predictivo de las Pruebas , Calcificación Vascular , Humanos , Calcificación Vascular/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Reproducibilidad de los Resultados , Masculino , Femenino , Técnicas de Imagen Sincronizada Cardíacas , Vasos Coronarios/diagnóstico por imagen , Persona de Mediana Edad , Anciano , Índice de Severidad de la EnfermedadRESUMEN
To compare the diagnostic value of ultrahigh-resolution CT-angiography (UHR-CTA) compared with high-pitch spiral CTA (HPS-CTA) using a first-generation, dual-source photon-counting CT (PCD-CT) scanner for preprocedural planning of transcatheter aortic valve replacement (TAVR). Clinically referred patients with severe aortic valve stenosis underwent both, retrospective ECG-gated cardiac UHR-CTA (collimation: 120 × 0.2 mm) and prospective ECG-triggered aortoiliac HPS-CTA (collimation: 144 × 0.4 mm, full spectral capabilities) for TAVR planning from August 2022 to March 2023. Radiation dose was extracted from the CT reports, and the effective dose was calculated. Two radiologists analyzed UHR-CTA and HPS-CTA datasets, assessing the image quality of the aortic annulus, with regard to the lumen visibility and margin delineation using a 4-point visual-grading scale (ranges: 4 = "excellent" to 1 = "poor"). Aortic annulus area (AAA) measurements were taken for valve prosthesis sizing, with retrospective UHR-CTA serving as reference standard. A total of 64 patients were included (mean age, 81 years ± 7 SD; 28 women) in this retrospective study. HPS-CTA showed a lower radiation dose, 4.1 mSv vs. 12.6 mSv (p < 0.001). UHR-CTA demonstrated higher image quality to HPS-CTA (median score, 4 [IQR, 3-4] vs. 3 [IQR, 2-3]; p < 0.001). Quantitative assessments of AAA from both CTA datasets were strongly positively correlated (mean 477.4 ± 91.1 mm2 on UHR-CTA and mean 476.5 ± 90.4 mm2 on HPS-CTA, Pearson r2 = 0.857, p < 0.001) with a mean error of 22.3 ± 24.6 mm2 and resulted in identical valve prosthesis sizing in the majority of patients (91%). Patients with lower image quality on HPS-CTA (score value 1 or 2, n = 28) were more likely to receive different sizing recommendations (82%). Both UHR-CTA and HPS-CTA acquisitions using photon-counting CT technology provided reliable aortic annular assessments for TAVR planning. While UHR-CTA offers superior image quality, HPS-CTA is associated with lower radiation exposure. However, severely impaired image quality on HPS-CTA may impact on prosthesis sizing, suggesting that immediate post-scan image evaluations may require complementary UHR-CTA scanning.
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Estenosis de la Válvula Aórtica , Válvula Aórtica , Técnicas de Imagen Sincronizada Cardíacas , Angiografía por Tomografía Computarizada , Electrocardiografía , Prótesis Valvulares Cardíacas , Valor Predictivo de las Pruebas , Diseño de Prótesis , Dosis de Radiación , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/fisiopatología , Femenino , Masculino , Estudios Retrospectivos , Anciano de 80 o más Años , Anciano , Reemplazo de la Válvula Aórtica Transcatéter/instrumentación , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Exposición a la Radiación , Toma de Decisiones Clínicas , Fotones , Tomografía Computarizada MultidetectorRESUMEN
BACKGROUND: The measurement of aortic dimensions and their evolution are key in the management of patients with aortic diseases. Manual assessment, the current guideline-recommended method and clinical standard, is subjective, poorly reproducible, and time-consuming, limiting the capacity to track aortic growth in everyday practice. Aortic geometry mapping (AGM) via image registration of serial computed tomography angiograms outperforms manual assessment, providing accurate and reproducible 3D maps of aortic diameter and growth rate. This observational study aimed to evaluate the accuracy and reproducibility of AGM on non-gated contrast-enhanced (CE-) and cardiac- and respiratory-gated (GN-) magnetic resonance angiographies (MRA). METHODS: Patients with thoracic aortic disease followed with serial CE-MRA (n = 30) or GN-MRA (n = 15) acquired at least 1 year apart were retrospectively and consecutively identified. Two independent observers measured aortic diameters and growth rates (GR) manually at several thoracic aorta reference levels and with AGM. Agreement between manual and AGM measurements and their inter-observer reproducibility were compared. Reproducibility for aortic diameter and GR maps assessed with AGM was obtained. RESULTS: Mean follow-up was 3.8 ± 2.3 years for CE- and 2.7 ± 1.6 years for GN-MRA. AGM was feasible in the 93% of CE-MRA pairs and in the 100% of GN-MRA pairs. Manual and AGM diameters showed excellent agreement and inter-observer reproducibility (ICC>0.9) at all anatomical levels. Agreement between manual and AGM GR was more limited, both in the aortic root by GN-MRA (ICC=0.47) and in the thoracic aorta, where higher accuracy was obtained with GN- than with CE-MRA (ICC=0.55 vs 0.43). The inter-observer reproducibility of GR by AGM was superior compared to manual assessment, both with CE- (thoracic: ICC= 0.91 vs 0.51) and GN-MRA (root: ICC=0.84 vs 0.52; thoracic: ICC=0.93 vs 0.60). AGM-based 3D aortic size and growth maps were highly reproducible (median ICC >0.9 for diameters and >0.80 for GR). CONCLUSION: Mapping aortic diameter and growth on MRA via 3D image registration is feasible, accurate and outperforms the current manual clinical standard. This technique could broaden the possibilities of clinical and research evaluation of patients with aortic thoracic diseases.
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Aorta Torácica , Enfermedades de la Aorta , Medios de Contraste , Imagenología Tridimensional , Angiografía por Resonancia Magnética , Variaciones Dependientes del Observador , Valor Predictivo de las Pruebas , Humanos , Reproducibilidad de los Resultados , Masculino , Femenino , Estudios Retrospectivos , Persona de Mediana Edad , Aorta Torácica/diagnóstico por imagen , Anciano , Medios de Contraste/administración & dosificación , Enfermedades de la Aorta/diagnóstico por imagen , Técnicas de Imagen Sincronizada Respiratorias , Adulto , Factores de Tiempo , Interpretación de Imagen Asistida por Computador , Técnicas de Imagen Sincronizada CardíacasRESUMEN
BACKGROUND: Despite the widespread use of cine MRI for evaluation of cardiac function, existing real-time methods do not easily enable quantification of ventricular function. Moreover, segmented cine MRI assumes periodicity of cardiac motion. We aim to develop a self-gated, cine MRI acquisition scheme with data-driven cluster-based binning of cardiac motion. METHODS: A Cartesian golden-step balanced steady-state free precession sequence with sorted k-space ordering was designed. Image data were acquired with breath-holding. Principal component analysis and k-means clustering were used for binning of cardiac phases. Cluster compactness in the time dimension was assessed using temporal variability, and dispersion in the spatial dimension was assessed using the Calinski-Harabasz index. The proposed and the reference electrocardiogram (ECG)-gated cine methods were compared using a four-point image quality score, SNR and CNR values, and Bland-Altman analyses of ventricular function. RESULTS: A total of 10 subjects with sinus rhythm and 8 subjects with arrhythmias underwent cardiac MRI at 3.0 T. The temporal variability was 45.6 ms (cluster) versus 24.6 ms (ECG-based) (p < 0.001), and the Calinski-Harabasz index was 59.1 ± 9.1 (cluster) versus 22.0 ± 7.1 (ECG based) (p < 0.001). In subjects with sinus rhythm, 100% of the end-systolic and end-diastolic images from both the cluster and reference approach received the highest image quality score of 4. Relative to the reference cine images, the cluster-based multiphase (cine) image quality consistently received a one-point lower score (p < 0.05), whereas the SNR and CNR values were not significantly different (p = 0.20). In cases with arrhythmias, 97.9% of the end-systolic and end-diastolic images from the cluster approach received an image quality score of 3 or more. The mean bias values for biventricular ejection fraction and volumes derived from the cluster approach versus reference cine were negligible. CONCLUSION: ECG-free cine cardiac MRI with data-driven clustering for binning of cardiac motion is feasible and enables quantification of cardiac function.
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Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Cinemagnética , Humanos , Imagen por Resonancia Cinemagnética/métodos , Interpretación de Imagen Asistida por Computador/métodos , Técnicas de Imagen Sincronizada Cardíacas/métodos , Función Ventricular , Análisis por Conglomerados , Reproducibilidad de los ResultadosRESUMEN
PURPOSE: The purpose of this survey was to evaluate the current state-of-art of pre-TAVI imaging in a large radiological professional community. METHODS: Between December 2022 and January 2023 all members of the Italian Society of Medical and Interventional Radiology (SIRM) were invited by the CT PRotocol Optimization group (CT-PRO group) to complete an online 24-item questionnaire about pre-TAVI imaging. RESULTS: 557 SIRM members participated in the survey. The greatest part of respondents were consultant radiologists employed in public hospitals and 84% claimed to routinely perform pre-TAVI imaging at their institutions. The most widespread acquisition protocol consisted of an ECG-gated CT angiography (CTA) scan of the aortic root and heart followed by a non-ECG-synchronized CTA of the thorax, abdomen, and pelvis. Contrast agent administration was generally tailored on the patient's body weight with a preference for using high concentration contrast media. The reports were commonly written by radiologists with expertise in cardiovascular imaging, and included all the measurements suggested by current guidelines for adequate pre-procedural planning. About 60% of the subjects affirmed that the Heart Team is present at their institutions, however only 7% of the respondents regularly attended the multidisciplinary meetings. CONCLUSIONS: This survey defines the current pre-TAVI imaging practice in a large radiological professional community. Interestingly, despite the majority of radiologists follow the current guidelines regarding acquisition and reporting of pre-TAVI imaging studies, there is still a noteworthy absence from multidisciplinary meetings and from the Heart Team.
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Angiografía por Tomografía Computarizada , Encuestas de Atención de la Salud , Pautas de la Práctica en Medicina , Valor Predictivo de las Pruebas , Humanos , Italia , Medios de Contraste/administración & dosificación , Técnicas de Imagen Sincronizada Cardíacas , Implantación de Prótesis de Válvulas Cardíacas , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/fisiopatología , Válvula Aórtica/diagnóstico por imagen , Radiólogos , Grupo de Atención al Paciente , FemeninoRESUMEN
BACKGROUND: Non-Cartesian magnetic resonance imaging trajectories at golden angle increments have the advantage of allowing motion correction and gating using intermediate real-time reconstructions. However, when the acquired data are cardiac binned for cine imaging, trajectories can cluster together at certain heart rates (HR) causing image artifacts. Here, we demonstrate an approach to reduce clustering by inserting additional angular increments within the trajectory, and optimizing them while still allowing for intermediate reconstructions. METHODS: Three acquisition models were simulated under constant and variable HR: golden angle (Mtrd), random additional angles (Mrnd), and optimized additional angles (Mopt). The standard deviations of trajectory angular differences (STAD) were compared through their interquartile ranges (IQR) and the Kolmogorov-Smirnov test (significance level: p = 0.05). Agreement between an image reconstructed with uniform sampling and images from Mtrd, Mrnd, and Mopt was analyzed using the structural similarity index measure (SSIM). Mtrd and Mopt were compared in three adults at high, low, and no HR variability. RESULTS: STADs from Mtrd were significantly different (p < 0.05) from Mopt and Mrnd. STAD (IQR × 10-2 rad) showed that Mopt (0.5) and Mrnd (0.5) reduced clustering relative to Mtrd (1.9) at constant HR. For variable HR, Mopt (0.5) and Mrnd (0.5) outperformed Mtrd (0.9). The SSIM (IQR) showed that Mopt (0.011) produced the best image quality, followed by Mrnd (0.014), and Mtrd (0.030). Mopt outperformed Mtrd at reduced HR variability in in-vivo studies. At high HR variability, both models performed well. CONCLUSION: This approach reduces clustering in k-space and improves image quality.