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OBJECTIVES: To evaluate at 1.5 and 3 T MRI the safety and performance of trademarked ENO®, TEO®, or OTO® pacing systems with automated MRI Mode and the image quality of non-enhanced MR examinations. METHODS: A total of 267 implanted patients underwent MRI examination (brain, cardiac, shoulder, cervical spine) at 1.5 (n = 126) or 3 T (n = 141). MRI-related device complications, lead electrical performances stability at 1-month post-MRI, proper functioning of the automated MRI mode and image quality were evaluated. RESULTS: Freedom from MRI-related complications at 1 month post-MRI was 100% in both 1.5 and 3 T arms (both p < 0.0001). The stability of pacing capture threshold was respectively at 1.5 and 3 T (atrial:: 98.9% (p = 0.001) and 100% (p < 0.0001); ventricular: both 100% (p < 0001)). The stability of sensing was respectively at 1.5 and 3 T (atrial: 100% (p = 0.0001) and 96.9% (p = 0.01); ventricular: 100% (p < 0.0001) and 99.1% (p = 0.0001)). All devices switched automatically to the programmed asynchronous mode in the MRI environment and to initially programmed mode after the MRI exam. While all MR examinations were assessed as interpretable, artifacts deteriorated a subset of examinations including mostly cardiac and shoulder ones. CONCLUSION: This study demonstrates the safety and electrical stability of ENO®, TEO®, or OTO® pacing systems at 1 month post-MRI at 1.5 and 3 T. Even if artifacts were noticed in a subset of examinations, overall interpretability was preserved. CLINICAL RELEVANCE STATEMENT: ENO®, TEO®, and OTO® pacing systems switch to MR-mode when detecting magnetic field and switch back on conventional mode after MRI. Their safety and electrical stability at 1 month post MRI were shown at 1.5 and 3 T. Overall interpretability was preserved. KEY POINTS: ⢠Patients implanted with an MRI conditional cardiac pacemaker can be safely scanned under 1.5 or 3 Tesla MRI with preserved interpretability. ⢠Electrical parameters of the MRI conditional pacing system remain stable after a 1.5 or 3 Tesla MRI scan. ⢠The automated MRI mode enabled the automatic switch to asynchronous mode in the MRI environment and to initial settings after the MRI scan in all patients.
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Fibrilação Atrial , Marca-Passo Artificial , Humanos , Segurança de Equipamentos/métodos , Estudos Prospectivos , Imageamento por Ressonância Magnética/métodosRESUMO
The value of biofeedback before elective coronary computed tomography angiography (CCTA) to reduce patients' heart rates (HR) was investigated in the current work. Sixty patients who received CCTA to exclude coronary artery disease were included in our study and separated into two groups: with biofeedback (W-BF) and without biofeedback (WO-BF). The W-BF group used a biofeedback device for 15 min before CCTA. HR was determined in each patient at four measurement time points (MTP): during the pre-examination interview (MTP1), positioning on the CT patient table before CCTA (MTP2), during CCTA image acquisition (MTP3), and after completing CCTA (MTP4). If necessary, beta-blockers were administered in both groups after MTP2 until a HR of less than 65 bpm was achieved. Two board-certified radiologists subsequently assessed the image quality and analyzed the findings. Overall, the need for beta-blockers was significantly lower in patients in the W-BF group than the WO-BF group (p = 0.032). In patients with a HR of 81-90, beta-blockers were not required in four of six cases in the W-BF group, whereas in the WO-BF group all patients needed beta-blockers (p = 0.03). The amount of HR reduction between MTP1 and MTP2 was significantly higher in the W-BF compared to the WO-BF group (p = 0.028). There was no significant difference between the W-BF and WO-BF groups regarding image quality (p = 0.179). By using biofeedback prior to elective CCTA, beta-blocker use could be decreased without compromising CT image quality and analysis, especially in patients with an initial HR of 81-90 bpm.
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Angiografia por Tomografia Computadorizada , Doença da Artéria Coronariana , Humanos , Angiografia Coronária/métodos , Angiografia por Tomografia Computadorizada/métodos , Frequência Cardíaca/fisiologia , Doença da Artéria Coronariana/terapia , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Free-breathing noncontrast-enhanced (non-CE) magnetic resonance angiography (MRA) techniques are of considerable interest for the diagnosis of acute pulmonary embolism (APE), due to the possibility for repeated examinations, avoidance of side effects from iodine-based contrast agents, and the absence of ionizing radiation exposure as compared to CE-computed tomographic angiography (CTA). PURPOSE: To analyze the clinical performance of free-breathing and electrocardiogram (ECG)-gated radial quiescent-interval slice-selective (QISS)-MRA compared to CE-CTA and to Cartesian balanced steady-state free precession (bSSFP)-MRA. STUDY TYPE: Prospective. SUBJECTS: Thirty patients with confirmed APE and 30 healthy volunteers (HVs). FIELD STRENGTH/SEQUENCE: Radial QISS- and bSSFP-MRA at 1.5T. ASSESSMENT: Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were computed to compare the pulmonary imaging quality between MRA methods. The pulmonary arterial tree was divided into 25 branches and an ordinal scoring system was used to assess the image quality of each pulmonary branch. The clinical performance of the two MRA techniques in accurately assessing APE was evaluated with respect to CE-CTA as the clinical reference standard. STATISTICAL TESTS: Wilcoxon signed-rank and Spearman's correlation tests were performed. Sensitivity and specificity of the MRA techniques were determined using CE-CTA as the clinical reference standard. RESULTS: Thrombus-mimicking artifacts appeared more frequently in lobar and peripheral arteries of patients with Cartesian bSSFP than with radial QISS-MRA (pulmonary trunk: 12.2% vs. 14.0%, P = 0.64; lobar arteries: 35.6% vs. 22.0%, P = 0.005, peripheral arteries: 74.4% vs. 49.0%, P < 0.001). The relative increases in SNR and of CNR provided by radial QISS-MRA with respect to Cartesian bSSFP-MRA were 30-35% (P-values of SNR/CNR, HVs: 0.09/0.09, patients: 0.03/0.02). The image quality of pulmonary arterial branches was considered good to excellent in 77.2% of patients with radial QISS-MRA and in 43.2% with Cartesian bSSFP-MRA (P < 0.0001). The clinical performance of radial QISS-MRA was higher than Cartesian bSSFP-MRA for grading embolism, with a total sensitivity of 86.0% vs. 80.6% and a specificity of 93.3% vs. 84.0%, respectively. DATA CONCLUSION: Radial QISS-MRA is a reliable and safe non-CE angiographic technique with promising clinical potential compared to Cartesian bSSFP-MRA and as an alternative technique to CE-CTA for the diagnosis of APE. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 3.
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Angiografia por Ressonância Magnética , Embolia Pulmonar , Angiografia por Tomografia Computadorizada , Meios de Contraste , Humanos , Estudos Prospectivos , Embolia Pulmonar/diagnóstico por imagem , Reprodutibilidade dos TestesRESUMO
OBJECTIVES: Radio frequency (RF) pulses in magnetic resonance imaging (MRI) can interact with implanted devices and cause tissue damage. However, there are new devices that can safely perform measurements with liberal MRI conditions such as an RF transmission field B1+rms ≤ 2.0 µT. We investigated whether MRI in this case is limited for these technical reasons. METHODS: We selected typical MRI protocols of six body regions (brain, cervical spine, lumbar spine, knee, liver, heart) using two typical 1.5T MRI scanners. Overall, we adapted 62 sequences to B1+rms conditions and evaluated their diagnostic quality. For this, we measured signal-to-noise-ratio (SNR), contrast-to-noise-ratio (CNR), and geometric deviation (GD) as quality parameters, using phantom studies. For questionnaire studies, we selected pairs of original and adapted sequences in healthy volunteers. Blinded radiologists rated the images as single sequence rating and in direct comparison. RESULTS: Roughly one-third of the checked sequences were below the B1+rms limit. Here, 56 of the 62 adapted sequences showed at least the same image quality in single ratings. A reduction in SNR and/or CNR was found with 31 sequences and only one sequence with considerably increased GD. Especially, sequences with original high B1+rms values, PD sequences, and sequences of the Siemens knee and heart protocol were difficult to adapt, whereas most TSE and IR sequences had no clinical limitations. CONCLUSION: By limiting the transmission field to B1+rms ≤ 2.0 µT, clinically relevant MR sequences can be adapted with nearly no reduction in image quality. Despite limiting the transmission field, high-quality MR imaging is possible. We could derive strategies for adaptation. KEY POINTS: ⢠Despite limiting the transmission field, high-quality MRI is possible. ⢠We could derive strategies for adapting the sequences to B1+rms≤ 2.0 µT. ⢠This enables high-quality MRI of different body regions for patients with AD.
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Encéfalo/diagnóstico por imagem , Fígado/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Imagens de Fantasmas , Próteses e Implantes , Ondas de Rádio , Voluntários Saudáveis , HumanosRESUMO
Background: Kawasaki disease (KD) is a paediatric multi-system vasculitis. Mainly, the coronary arteries become affected due to acute inflammation and formation of coronary artery aneurysms (CAAs) may occur. As the size of the CAA increases, so does the risk of clinical complications and serious cardiac outcomes. These patients may experience life-threatening thrombotic coronary artery occlusion and myocardial ischaemia unless antiplatelet and anticoagulation therapy is not initiated in a timely manner.1. Case summary: This case report presents a 12-year-old patient with KD who developed CAAs in two coronary arteries despite initial administration of intravenous immunoglobulins and acetylsalicylic acid, followed by extensive thrombosis of both coronary arteries, although antithrombotic therapy was started after the diagnosis of CAAs. Discussion: Our case is notable because of the severity of the clinical manifestation despite the administration of antiplatelet agents and anticoagulants. It could be speculated that the development of coronary thrombosis in this case might be strongly correlated with the late initiation of oral anticoagulation. The high-quality images of the affected coronary arteries in such a young patient could be of educational value.
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In a female patient with acute cardiac decompensation, an auxiliary finding of a giant left atrium emerged. The surgical therapy of the atrial reduction, in addition to a mitral valve replacement and a coronary artery bypass grafting, is hereby presented.
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We present a novel computational model for the dynamics of alveolar recruitment/derecruitment (RD), which reproduces the underlying characteristics typically observed in injured lungs. The basic idea is a pressure- and time-dependent variation of the stress-free reference volume in reduced dimensional viscoelastic elements representing the acinar tissue. We choose a variable reference volume triggered by critical opening and closing pressures in a time-dependent manner from a straightforward mechanical point of view. In the case of (partially and progressively) collapsing alveolar structures, the volume available for expansion during breathing reduces and vice versa, eventually enabling consideration of alveolar collapse and reopening in our model. We further introduce a method for patient-specific determination of the underlying critical parameters of the new alveolar RD dynamics when integrated into the tissue elements, referred to as terminal units, of a spatially resolved physics-based lung model that simulates the human respiratory system in an anatomically correct manner. Relevant patient-specific parameters of the terminal units are herein determined based on medical image data and the macromechanical behavior of the lung during artificial ventilation. We test the whole modeling approach for a real-life scenario by applying it to the clinical data of a mechanically ventilated patient. The generated lung model is capable of reproducing clinical measurements such as tidal volume and pleural pressure during various ventilation maneuvers. We conclude that this new model is an important step toward personalized treatment of ARDS patients by considering potentially harmful mechanisms-such as cyclic RD and overdistension-and might help in the development of relevant protective ventilation strategies to reduce ventilator-induced lung injury (VILI).
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Alvéolos Pulmonares , Síndrome do Desconforto Respiratório , Humanos , Síndrome do Desconforto Respiratório/etiologia , Síndrome do Desconforto Respiratório/terapia , Pulmão , Respiração Artificial/efeitos adversos , RespiraçãoRESUMO
BACKGROUND: Liver fibrosis has been recognized as a long-term morbidity associated with Fontan circulation (Fontan-associated liver disease, FALD). The pathophysiology of FALD is not completely understood and abnormal flow dynamics may be associated with this condition. Liver hemodynamics can be quantitatively evaluated with four-dimensional phase-contrast flow magnetic resonance imaging (4D PC flow MRI). The study aimed to evaluate suitability of liver 4D PC flow MRI in Fontan patients and relate flow measurements to normal values and FALD severity. PATIENTS AND METHODS: Twenty-two Fontan patients were examined by 4D PC flow MRI at 1.5 Tesla to assess mesenteric, portal, splenic, and hepatic venous blood flow. Severity of FALD was graded based on routine screening, including abdominal ultrasound and laboratory tests. RESULTS: Median age was 18.5 (interquartile range, IQR 15.5-20.2) years. FALD was graded as "none or mild" in 16 and as "moderate to severe" in six cases. Ten patients presented at least one feature of portal hypertension (ascites, splenomegaly, or thrombocytopenia). For the entire cohort, blood flow in the superior mesenteric, splenic, and portal vein was lower than reported in the literature. No significant differences were observed in relation to FALD severity. Features of portal hypertension were associated with a higher splenic vein blood flow (0.34 ± 0.17 vs. 0.20 ± 0.07 l/min, p = 0.046). Splenic vein blood flow was negatively correlated to platelet count (r = -0.590, p = 0.005). CONCLUSIONS: 4D PC flow MRI appears suitable to assess liver hemodynamics in Fontan patients and integration into clinical follow-up might help to improve our understanding of FALD.
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Background: The aim of this work was to create and evaluate a preoperative non-contrast-enhanced (CE) magnetic resonance imaging (MRI)/angiography (MRA) protocol to assess renal function and visualize renal arteries and any abnormalities in potential living kidney donors. Methods: In total, 28 subjects were examined using scintigraphy to determine renal function. In addition, 3D-pseudocontinuous arterial spin labeling (pCASL), a 2D-non-CE electrocardiogram-triggered radial quiescent interval slice-selective (QISS-MRA), and 4D-CE time-resolved angiography with interleaved stochastic trajectories (CE-MRA) were performed to assess renal perfusion, visualize renal arteries and detect any abnormalities. Two glomerular filtration rates [described by Gates (GFRG) and according to the Chronic Kidney Disease Epidemiology Collaboration formula (GFRCKD-EPI)]. The renal volumes were determined using both MRA techniques. Results: The mean value of regional renal blood flow (rRBF) on the right side was significantly higher than that on the left. The agreements between QISS-MRA and CE-MRA concerning the assessment of absence or presence of an aberrant artery and renal arterial stenosis were perfect. The mean renal volumes measured in the right kidney with QISS-MRA were lower than the corresponding values of CE-MRA. In contrast, the mean renal volumes measured in the left kidney with both MRA techniques were similar. The correlation between the GFRG and rRBF was compared in the same manner as that between GFRCKD-EPI and rRBF. Conclusion: The combination of pCASL and QISS-MRA constitute a reliable preoperative protocol with a total measurement time of <10 min without the potential side effects of gadolinium-based contrast agents or radiation exposure.
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Introduction: Unilateral pulmonary edema (UPE) is a potential complication after mitral valve surgery (MVS), and its cause is not yet fully understood. Definitions are inconsistent, and previous studies have reported wide variance in the incidence of UPE. This research aims at the evaluation of the Radiographic Assessment of Lung Edema (RALE) score concerning assessment of UPE after MVS in order to provide an accurate and consistent definition of this pathology. Methods and Results: Postoperative chest X-ray images of 676 patients after MVS (minimally invasive MVS, n = 434; conventional MVS, n = 242) were retrospectively analyzed concerning presence of UPE. UPE was diagnosed only after exclusion of other pathologies up until the eighth postoperative day. RALE values were calculated for each patient. ROC analysis was performed to assess diagnostic performance. UPE was diagnosed in 18 patients (2.8%). UPE occurred significantly more often in the MI-MVS group (p = 0.045; MI-MVS n = 15; C-MVS n = 3). Postoperative RALE values for the right hemithorax (Q1 + Q2) > 12 and the right-to-left RALE difference ((Q1 + Q2) - (Q3 + Q4)) > 13 provide a sensitivity of up to 100% and 94.4% and a specificity of up to 88.4% and 94.2% for UPE detection. Conclusion: The RALE score is a practical tool for assessment of chest X-ray images after MVS with regard to UPE and provides a clear definition of UPE. In addition, it enables objective comparability when assessing of the postoperative course. The given score thresholds provide a sensitivity and specificity of up to 94%. Further, UPE after MVS seems to be a rather rare pathology with an incidence of 2.6%.
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Cardiac CT obtained in acute ischemic stroke patients can facilitate timely detection of cardiac sources of embolism and guide secondary prevention strategies. Spectral CT exploiting the simultaneous acquisition of separate higher-energy and lower-energy photon spectrum datasets has the potential to improve contrast between thrombi and cardiac structures. This study aimed to investigate the diagnostic value of spectral cardiac CT compared to conventional CT for the detection of cardiac thrombi in acute stroke patients. Patients with acute ischemic stroke undergoing spectral cardiac CT were retrospectively included. Conventional CT images, virtual 55 keV monoenergetic (monoE55), z-effective (zeff), and iodine density images were evaluated for the presence of thrombi. Diagnostic certainty was rated on a 5-point Likert scale. Contrast ratios were calculated for all reconstructions. 63 patients with 20 thrombi were included. Four thrombi were missed on conventional images but detected on spectral reconstructions. MonoE55 achieved the highest scores for diagnostic certainty. Contrast ratios were highest on iodine density images, followed by monoE55, conventional and zeff (p < 0.005). Spectral cardiac CT adds diagnostic benefit for the detection of intra-cardiac thrombi in acute ischemic stroke patients compared to conventional CT.
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Iodo , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Estudos Retrospectivos , Razão Sinal-Ruído , Tomografia Computadorizada por Raios X/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodosRESUMO
OBJECTIVES: To evaluate the ability of non-contrast enhanced magnetic resonance imaging (MRI) techniques to characterize Fontan associated liver disease (FALD) in adolescent and adult Fontan patients. METHODS: Fontan patients (n = 29) and healthy controls (n = 13) underwent an MRI protocol with T1, T2 and Apparent Diffusion Coefficient (ADC) mapping. Routine FALD screening included abdominal ultrasound and laboratory testing. RESULTS: Median follow-up after Fontan operation was 15.1 (IQR 12.0-16.8) years. Distinct differences in tissue characteristics were visualized. T1 and T2 relaxation times were prolonged in Fontan patients, particularly of the right lobe (T1: 745 (IQR 715-784) ms vs. 586 (IQR 555-602) ms, p < 0.001; T2: 63 (IQR 59-64) ms vs. 58 (IQR 56-60) ms, p = 0.002). Left lobe ADC was lower in Fontan patients (1.10 (IQR 1.06-1.18) x 10-3 mm2/s vs. 1.23 (IQR 1.19-1.29) x 10-3 mm2/s, p < 0.001). T2 mapping was able to differentiate between controls and Fontan patients with different FALD severity. Right lobe T2 was higher in patients with moderate or severe in comparison to those with no or mild changes and healthy controls (64 (IQR 61-67) ms vs. 60 (IQR 59-63) ms vs. 58 (IQR 56-60) ms, p = 0.001). CONCLUSIONS: Non-contrast enhanced MRI methods are able to visualize regional differences in liver tissue characteristics. T1 and T2 relaxation times were prolonged in Fontan patients suggestive of fibrosis or congestive hepatopathy, while reduced ADC might reflect impaired microperfusion. These methods have promising clinical potential for detection of liver abnormalities in Fontan patients. The usefulness of T2 mapping to grade FALD severity merits further investigation.
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Técnica de Fontan , Hepatopatias , Adolescente , Adulto , Imagem de Difusão por Ressonância Magnética , Técnica de Fontan/efeitos adversos , Humanos , Hepatopatias/diagnóstico por imagem , Hepatopatias/cirurgia , Imageamento por Ressonância MagnéticaRESUMO
PURPOSE: Contrast-enhanced (CE) angiographic techniques, such as computed tomographic angiography (CE-CTA), are most commonly used for follow-up imaging after endovascular aneurysm repair. In this study, CE-CTA and non-CE QISS-MRA were compared for the first time for assessing endoleaks and aneurysms at follow-up after abdominal EVAR. METHODS: Our study included 20 patients (17 male, median age 79.8 years) who underwent radial QISS-MRA and CE-CTA after EVAR at their first follow-up examination. Two interventional radiologists evaluated datasets from both techniques in each patient concerning presence of endoleaks, types of endoleaks, aneurysm diameter, and image quality. Interobserver and intermodal agreement were assessed with Cohen's Kappa. RESULTS: Image quality was rated as excellent or good for both modalities by both observers. Ferromagnetic embolization materials cause hyperdense artifacts in CE-CTA causing aneurysm sac diameter measurements to be inaccurate by up to 1 cm. Type 2 endoleaks with low-flow characteristics in CE-CTA were overlooked compared to radial QISS-MRA. Compared to CE-CTA, all endoleaks after abdominal EVAR were detected and classified correctly on QISS-MRA. The interobserver agreement between CE-CTA and QISS-MRA was almost perfect, except for type 2 endoleaks, where agreement was substantial. Intermodal aneurysm diameter correlate "very strongly" for both observers. CONCLUSIONS: Radial QISS-MRA is a contrast agent free technique for diagnosing and monitoring all types of endoleaks and aneurysms in patients after abdominal EVAR. It provides information about specific clinical questions concerning aneurysm diameter and presence and types of endoleaks without radiation exposure and the side effects associated with iodine-based contrast agents.
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We report a rare association of common arterial trunk with left pulmonary artery sling and highlight the importance of cross-sectional imaging in complex congenital cardiac lesions. The patient was antenatally diagnosed with common arterial trunk and underwent surgical repair in the neonatal period. At the age of 20 months, the patient presented with respiratory symptoms and increased right ventricular pressure. Multislice computed tomography demonstrated a pulmonary sling with compression of the distal trachea. Surgical correction of the pulmonary sling and change of the right ventricular to pulmonary artery conduit to a bigger size was performed.
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PURPOSE: To investigate the diagnostic value of dual-layer spectral detector computed tomography (SDCT) in detecting posttraumatic prevertebral hematoma of the cervical spine by including electron density images. METHODS: 38 patients with post-traumatic imaging of the cervical spine were included in this study and received both SDCT and MRI examinations. MRI was set as the reference and combined conventional/electron density (Câ+âED) images were compared to conventional CT (CCT) images alone. RESULTS: A total of 18 prevertebral hematomas were identified. Reader 1 identified 14 of 18 and reader 2 15 of 18 prevertebral hematomas by using Câ+âED reconstructions. Readers 1 and 2 detected 6 and 9 of 18 hematomas on CCT, respectively. CCT showed a sensitivity of 33-50â% and a specificity of 75-80â%, while for Câ+âED reconstructed images the sensitivity was 77-83â% and the specificity was 85-90â%. Accuracy increased from 55-66â% to 84â% by using Câ+âED images. The minimum thickness for detecting hematoma on Câ+âED images was 3âmm. The sizes of prevertebral hematoma on CCT/Câ+âED were not significantly under- or overestimated compared to the MRI reference. There was a significant difference between the two readers for measuring hematoma sizes on CCT (pâ=â0.04). Readers showed an excellent inter-rater reliability (kappaâ=â0.82) for Câ+âED images and a moderative inter-rater reliability (kappaâ=â0.44) for CCT. CONCLUSION: With SDCT, the diagnostic accuracy for detecting post-traumatic prevertebral hematoma is improved by using combined conventional and electron density reconstructions compared to conventional images alone. KEY POINTS: · SDCT has a high potential for detecting post-traumatic prevertebral hematomas of the cervical spine by using combined conventional and electron density images.. · Prevertebral hematomas with a thickness of less than 3âmm cannot be reliably identified by SDCT.. · There is no discernible value of conventional SDCT images for diagnosing prevertebral hematoma.. CITATION FORMAT: · Sedaghat S, Langguth P, Larsen N etâal. Diagnostic Accuracy of Dual-Layer Spectral CT Using Electron Density Images to Detect Post-Traumatic Prevertebral Hematoma of the Cervical Spine. Fortschr Röntgenstr 2021; 193: 1445â-â1450.
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Vértebras Cervicais , Elétrons , Vértebras Cervicais/diagnóstico por imagem , Hematoma/diagnóstico por imagem , Humanos , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios XRESUMO
This work focuses on implementing a standardized and symptom-oriented flowchart for advanced cardiac imaging in a 24/7 emergency setting using a dual-layer spectral detector CT system. This flowchart was designed to optimize patient management and standardize imaging workflow. It includes acquisition parameters and contrast agent protocols for the most relevant clinical questions regarding cardiac CT imaging in the interdisciplinary emergency department. The automated reconstruction of symptom-oriented spectral images represents an additional strength here. This implementation is designed to be time-efficient and user-friendly and improves diagnostic quality, independent of the qualification level of clinical and technical personnel.
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Meios de Contraste , Tomografia Computadorizada por Raios X , Serviço Hospitalar de Emergência , Humanos , Design de SoftwareRESUMO
OBJECTIVE: To test the hypothesis that ventricular and atrial function are different between patients with transposition of the great arteries (TGA) after arterial switch operation (ASO) and healthy controls. METHODS: 103 consecutive patients with TGA (median age: 16.7 years, 4.3-39.6 years, 71.8% male) were compared with 77 controls (median age: 15.4 years, 6.3-43.2 years, 66.2% male). Biventricular and biatrial function were assessed using standard cardiovascular magnetic resonance (CMR) techniques and feature tracking. Group comparison was performed with conventional non-parametrical statistics and machine learning methods to find the variables most discriminative between patients and controls. These variables were used to build a multivariable logistic regression model to assess the case-control status. RESULTS: Markers of left and right ventricular function (LV; RV) (ejection fraction, MAPSE, TAPSE, LV long-axis strain) as well as LV global longitudinal (-20.7 (-24.1; -17.9) vs -23.7 (-26.1; -21.6), p<0.001), circumferential (-29.4 (-32.2; -26.5) vs -30.5 (-33.6; 29), p=0.001) and atrial longitudinal strain (left atrium (LA): 23.3 (18.6; 28.8) vs 36.7 (30.7; 44), p<0001; right atrium: 21.7 (18.2; 27.8) vs 34.9 (26.9; 40.3), p<0.001) were reduced in patients compared with controls using non-parametrical testing. The logistic regression model including the most discriminative variables from univariate and machine learning analysis demonstrated significant differences between patients and controls only for TAPSE and LA global longitudinal strain. CONCLUSIONS: Biventricular and biatrial function are largely preserved after ASO for TGA. Using a comprehensive CMR protocol along with statistical machine learning methods and a regression approach, only RV longitudinal function and LA function are significantly impaired.
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Transposição das Grandes Artérias , Função do Átrio Esquerdo/fisiologia , Ventrículos do Coração/fisiopatologia , Transposição dos Grandes Vasos/cirurgia , Função Ventricular Esquerda/fisiologia , Função Ventricular Direita/fisiologia , Adolescente , Adulto , Criança , Pré-Escolar , Ecocardiografia/métodos , Feminino , Seguimentos , Ventrículos do Coração/diagnóstico por imagem , Humanos , Imagem Cinética por Ressonância Magnética , Masculino , Período Pós-Operatório , Estudos Retrospectivos , Fatores de Tempo , Transposição dos Grandes Vasos/diagnóstico , Transposição dos Grandes Vasos/fisiopatologia , Adulto JovemRESUMO
PURPOSE: Recurrent stroke is considered to increase the incidence of severe disability and death. For correct risk assessment and patient management it is essential to identify the origin of stroke at an early stage. Transthoracic echocardiography (TTE) is the initial standard of care for evaluating patients in whom a cardioembolic source of stroke (CES) is suspected but its diagnostic capability is limited. Transesophageal echocardiography (TEE) is considered as gold standard; however, this approach is time consuming, semi-invasive and not always feasible. We hypothesized that adding a delayed-phase cardiac computed tomography (cCT) to initial multimodal CT might represent a valid alternative to routine clinical echocardiographic work-up. MATERIAL AND METHODS: Patients with suspected acute cardioembolic stroke verified by initial multimodal CT and subsequently examined with cCT were included. The cCT was evaluated for presence of major CES and compared to routine clinical echocardiographic work-up. RESULTS: In all, 102 patients with suspected acute CES underwent cCT. Among them 60 patients underwent routine work-up with echocardiography (50 TTE and only 10 TEE). By cCT 10/60 (16.7%) major CES were detected but only 4 (6.7%) were identified by echocardiography. All CES observed by echocardiography were also detected by cCT. In 8 of 36 patients in whom echocardiography was not performed cCT also revealed a major CES. CONCLUSION: These preliminary results show the potential diagnostic yield of delayed-phase cCT to detect major CES and therefore could accelerate decision-making to prevent recurrence stroke. To confirm these results larger studies with TEE as the reference standard and also compared to TTE would be necessary.