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1.
J Cardiovasc Magn Reson ; 26(1): 100007, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38211509

RESUMEN

"Cases of SCMR" is a case series on the SCMR website (https://www.scmr.org) for the purpose of education. The cases reflect the clinical presentation, and the use of cardiovascular magnetic resonance (CMR) in the diagnosis and management of cardiovascular disease. The 2022 digital collection of cases are presented in this manuscript.


Asunto(s)
Enfermedades Cardiovasculares , Valor Predictivo de las Pruebas , Humanos , Enfermedades Cardiovasculares/diagnóstico por imagen , Enfermedades Cardiovasculares/terapia , Persona de Mediana Edad , Femenino , Masculino , Anciano , Imagen por Resonancia Magnética , Adulto , Pronóstico , Adulto Joven
2.
Respir Med Case Rep ; 16: 120-1, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26744675

RESUMEN

There is a complex interaction between the heart and the lungs. We report on a healthy female who performs breath hold diving at a high, international level. In order to optimize pressure equalization during diving and to increase oxygen available, apneists employed a special breathing maneuver, so called "lung packing". Based on cardiac MRI we could demonstrate impressive effects of this maneuver on left ventricular geometry and hemodynamics. Beyond the fact, that our findings support the concept of pulmonary -cardiac interrelationship, it should be emphasized, that the reported, extreme breathing maneuver could have detrimental consequences due to reduction of stroke volume and cardiac output.

3.
Acta Cardiol ; 68(3): 247-53, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23882869

RESUMEN

INTRODUCTION: The gold standard for identifying and grading tricuspid valve regurgitation is transthoracic echocardiography. However, the acoustic window using transthoracic echocardiography is not always sufficient to quantify the amount of regurgitation. Time-resolved imaging of contrast kinetics (TRICKS) is a 4-dimensional magnetic resonance angiography option with high spatial and temporal resolution. The aim of the present study is to find out whether identification of patients with severe tricuspid valve regurgitation by using TRICKS angiography is feasible. METHODS: TRICKS angiography was performed in a 3T-CMR-scanner after antecubital injection of gadolinium dimeglumine during breath hold. Retrograde appearance of contrast agent in the hepatic veins was classified as severe tricuspid regurgitation (TR). Additional semi quantification of retrograde perfusion was performed by temporal signal intensity curve (SIC) analysis in the hepatic veins close to their drainage into the inferior vena cava. Transthoracic echocardiography (TTE) using the actual European guidelines on the management of valvular heart disease served as gold standard forTR grading. RESULTS: 185 patients (57 +/- 17 years) with TR ranging from no to severe TR were analysed prospectively. 14 (7.6%) patients had severe TR, 27 (14.6%) showed moderate, 137 (74.1%) mild and 7 (3.8%) no TR. TRICKSangiography identified 13 patients with retrograde contrast appearance in the hepatic veins, of whom all had severe TR in TTE. No patient with echocardiographic mild or moderate TR was graded as severe TR using TRICKSangiography. One patient with echocardiographic severe TR showed neither in the visual analysis nor in SIC analysis retrograde appearance of contrast agent in the hepatic veins. Overall, the sensitivity for detecting severe TR using TRICKSangiography was 93% with a specificity of 100%. The positive predictive value was 100%, the negative predictive value 99%. For severe TR there was no intra- and interobserver variability. CONCLUSION: MRTRICKSangiography is a very reliable tool to identify patients with severeTR by the imaging of retrograde appearance of contrast agent in the hepatic veins. Sensitivity and specificity of this approach is very high with no intra- and interobserver variability.


Asunto(s)
Velocidad del Flujo Sanguíneo , Medios de Contraste , Gadolinio DTPA , Angiografía por Resonancia Magnética/métodos , Imagen por Resonancia Cinemagnética/instrumentación , Insuficiencia de la Válvula Tricúspide/diagnóstico , Anciano , Ecocardiografía , Diseño de Equipo , Femenino , Estudios de Seguimiento , Humanos , Cinética , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Insuficiencia de la Válvula Tricúspide/fisiopatología
4.
Acta Cardiol ; 66(4): 489-97, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21894806

RESUMEN

OBJECTIVE: Multi-breath hold cine-imaging (standard-2D-SSFP) is the standard technique for ventricular function assessment. However, image acquisition is time-consuming and breath holding is required. Ultrafast 2D real-time imaging (2D real time-SSFP) does not require breath holding, but spatial resolution is sacrificed. The accuracy of 2D real time-SSFP free-breathing ventricular function assessment by using an automated contour detection programme has not been systematically studied. METHODS AND RESULTS: Twenty-eight subjects (14 with impaired LV function) were investigated by 1.5 Tesla magnetic resonance imaging. Left ventricular short-axis images were acquired with multi-breath hold standard 2D-SSFP and free-breathing 2D real time-SSFP. LV-volumes (EDV, ESV), EF, and mass were determined using a semi-automated contour detection programme. EDV, ESV, EF, and mass were not significantly different between real time- and standard 2D-SSFP in subjects (absolute differences: EDV 3.2 +/- 0.7 mL, ESV 3.0 +/- 0.3 mL, EF 1.9 +/- 0.4%, mass 0.8 +/- 0.4 g; P > or = 0.78) and patients (absolute differences: EDV= 3.0 +/- 0.8 mL, ESV 3.3 +/- 1.0 mL, EF 0.9 +/- 0.5%, mass 0.9 +/- 0.5 g; P > or = 0.73). Automated contour detection required extensive manual correction for real-time imaging (< or = 86%). CONCLUSIONS: Differences in LV function measurements between real-time and standard 2D-SSFP are small, and not significant. Real-time SSFP may be used for rapid LV function assessment when examination time is limited.


Asunto(s)
Imagen por Resonancia Cinemagnética/métodos , Disfunción Ventricular Izquierda/diagnóstico , Función Ventricular Izquierda , Adulto , Anciano , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/fisiopatología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad
5.
Acta Cardiol ; 66(3): 349-57, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21744705

RESUMEN

OBJECTIVE: Papillary muscles and trabeculae for ventricular function analysis are known to significantly contribute to accurate volume and mass measurements. Fast imaging techniques such as three-dimensional steady-state free precession (3D SSFP) are increasingly being used to speed up imaging time, but sacrifice spatial resolution. It is unknown whether 3D SSFP, despite its reduced spatial resolution, allows for exact delineation of papillary muscles and trabeculations. We therefore compared 3D SSFP ventricular function measurements to those measured from standard multi-breath hold two-dimensional steady-state free precession cine images (standard 2D SSFP). METHODS AND RESULTS: 14 healthy subjects and 14 patients with impaired left ventricularfunction underwent 1.5 Tesla cine imaging. A stack of short axis images covering the left ventricle was acquired with 2D SSFP and 3D SSFP. Left ventricular volumes, ejection fraction, and mass were determined. Analysis was performed by substracting papillary muscles and trabeculae from left ventricular volumes. In addition, reproducibility was assessed. EDV, ESV, EF, and mass were not significantly different between 2D SSFP and 3D SSFP (mean difference healthy subjects: -0.06 +/- 3.2 ml, 0.54 +/- 2.2 ml, -0.45 +/- 1.8%, and 1.13 +/- 0.8 g, respectively; patients: 1.36 +/- 2.8 ml, -0.15 3.5 ml, 0.86 +/- 2.5%, and 0.91 +/- 0.9 g, respectively; P > or = 0.095). Intra- and interobserver variability was not different for 2D SSFP (P > or = 0.64 and P > or = 0.397) and 3D SSFP (P > or = 0.53 and P > or = 0.47). CONCLUSIONS: Differences in volumes, EF, and mass measurements between 3D SSFP and standard 2D SSFP are very small, and not statistically significant. 3D SSFP may be used for accurate ventricular function assessment when papillary muscles and trabeculations are to be taken into account.


Asunto(s)
Imagen por Resonancia Cinemagnética/métodos , Músculos Papilares/fisiopatología , Disfunción Ventricular Izquierda/fisiopatología , Función Ventricular Izquierda/fisiología , Adulto , Anciano , Diástole/fisiología , Femenino , Corazón/fisiopatología , Humanos , Imagenología Tridimensional , Persona de Mediana Edad , Sístole/fisiología
6.
Acta Radiol ; 52(6): 624-31, 2011 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-21525106

RESUMEN

BACKGROUND: Stress-rest perfusion magnetic resonance imaging (MRI) has become one of the major indications for cardiovascular MRI. Standard multibreath hold short-axis image acquisition is the gold standard for LV function assessment and part of a comprehensive stress-rest perfusion MRI study, but takes up to 10 min. The total scan time could significantly be shortened when cine imaging would be performed between stress and rest perfusion. PURPOSE: To systematically study whether adenosine, albeit its short half-life time, influences LV function measurements in this setting. MATERIAL AND METHODS: Thirty-nine patients with suspected and/or known coronary artery disease underwent 3-Tesla adenosine (140 µg/min/kg) stress-rest perfusion MRI. A stack of short-axis slices covering the entire ventricles was acquired before and ≥3 min after adenosine infusion using standard multibreath-hold 2D steady-state free precession imaging. LV volumes (EDV, ESV), EF, and mass were calculated by the slice summation method, and wall motion was assessed using a 4-point scoring scale. Reproducibility was assessed by Bland-Altman statistics. RESULTS: EDV, ESV, EF, and mass were not significantly different between the two imaging time points (before versus after adenosine administration) in all patients (P ≥ 0.346) and patients with impaired LV function (P ≥ 0.718). Wall motion scores did not differ either (P ≥ 0.124). Inter-observer variability before (P ≥ 0.468) and after (P ≥ 0.451) adenosine infusion was low. CONCLUSION: Short-axis cine imaging for LV function assessment can accurately be performed between stress and rest imaging. These data demonstrate that potential effects of adenosine on LV function are of short duration, and propose a new time-saving imaging protocol without compromising accuracy.


Asunto(s)
Adenosina/farmacología , Enfermedad de la Arteria Coronaria/diagnóstico , Prueba de Esfuerzo/métodos , Angiografía por Resonancia Magnética , Imagen por Resonancia Cinemagnética , Vasodilatadores/farmacología , Disfunción Ventricular Izquierda/diagnóstico , Adulto , Anciano , Medios de Contraste , Enfermedad de la Arteria Coronaria/fisiopatología , Electrocardiografía , Femenino , Gadolinio DTPA , Humanos , Interpretación de Imagen Asistida por Computador , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estadísticas no Paramétricas , Disfunción Ventricular Izquierda/fisiopatología
7.
Acta Radiol ; 52(4): 385-92, 2011 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-21498278

RESUMEN

BACKGROUND: Three Tesla cardiovascular magnetic resonance imaging (3T-CMR) is increasingly used in clinical practice. Despite many advantages one drawback is that ECG signal disturbances and artifacts increase with higher magnetic field strength resulting in trigger problems and false gating. This particularly affects cardiac imaging because most pulse sequences require ECG triggering. Pulse wave (PW) triggering is robust and might have advantages over ECG triggering. PURPOSE: To evaluate differences in left ventricular (LV) function as an integral part of most CMR studies between ECG- and PW-triggered short-axis imaging using 3T-CMR. MATERIAL AND METHODS: Forty-three patients underwent multiple short-axis cine imaging for LV-function assessment with ECG and PW triggering using standard multibreath hold steady-state free precession. LV-volumes (EDV, ESV), ejection fraction (EF), and mass were determined by slice summation. LV-wall motion was assessed by using a 4-point scoring scale. Bland Altman statistics for inter-observer variability were performed. RESULTS: ECG triggering failed in 15 patients (34.8%). Thus, analysis was performed in 28 patients (13 with impaired LV function). Difference in volumes (EDV 0.13 ± 1.8 mL, ESV 0.59 ± 1.1 mL), EF (-0.32 ± 0.6%) and mass (0.01 ± 1.1 g) between ECG and PW triggering were very small and significant only for ESV and EF (p ≤ 0.011). In patients with impaired LV function (n = 19) differences were not significant (p ≥ 0.128). Wall motion scores did not differ between ECG and PW triggering (p ≥ 0.295). Inter-observer variability for function measurements was low. CONCLUSION: Short-axis cine imaging for LV-function assessment can accurately be performed using PW triggering on 3T magnets, and may be used in clinical practice when ECG triggering is disturbed.


Asunto(s)
Electrocardiografía , Imagen por Resonancia Cinemagnética/métodos , Función Ventricular Izquierda , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Volumen Sistólico
8.
Radiology ; 251(1): 50-7, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19332846

RESUMEN

PURPOSE: To prospectively analyze the myocardial distribution of late gadolinium enhancement (LGE) with delayed-enhancement cardiac magnetic resonance (MR) imaging, to compare the prevalence of this distribution in nonprofessional male marathon runners with that in asymptomatic control subjects, and to examine the prognostic role of LGE. MATERIALS AND METHODS: Institutional review board and ethics committee approval were obtained for this study, and all subjects provided written informed consent. Two-dimensional inversion-recovery segmented k-space gradient-echo MR sequences were performed after administration of a gadolinium-containing contrast agent in 102 ostensibly healthy male runners aged 50-72 years who had completed at least five marathons during the past 3 years and in 102 age-matched control subjects. Predominantly subendocardial regions of LGE typical of myocardial infarction (hereafter, coronary artery disease [CAD] pattern) were distinguished from a predominantly midmyocardial patchy pattern of LGE (hereafter, non-CAD pattern). Marathon runners with LGE underwent repeat cardiac MR imaging and additional adenosine perfusion imaging. Runners were followed up for a mean of 21 months +/- 3 (standard deviation) after initial presentation. The chi(2), Fisher exact, and McNemar exact tests were used for comparisons. Event-free survival rates were estimated with the Kaplan-Meier method, and overall group differences were evaluated with log-rank statistics. RESULTS: Of the 102 runners, five had a CAD pattern of LGE, and seven had a non-CAD pattern of LGE. The CAD pattern of LGE was located in the territory of the left anterior descending coronary artery more frequently than was the non-CAD pattern (P = .0027, Fisher exact test). The prevalence of LGE in runners was higher than that in age-matched control subjects (12% vs 4%; P = .077, McNemar exact test). The event-free survival rate was lower in runners with myocardial LGE than in those without myocardial LGE (P < .0001, log-rank test). CONCLUSION: Ostensibly healthy marathon runners have an unexpectedly high rate of myocardial LGE, and this may have diagnostic and prognostic relevance.


Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/epidemiología , Gadolinio , Imagen por Resonancia Magnética/estadística & datos numéricos , Carrera/estadística & datos numéricos , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/epidemiología , Anciano , Causalidad , Comorbilidad , Alemania/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Resistencia Física , Pronóstico , Reproducibilidad de los Resultados , Medición de Riesgo/métodos , Factores de Riesgo , Sensibilidad y Especificidad
9.
Clin Res Cardiol ; 97(5): 288-97, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18389165

RESUMEN

Balloon aortic valvuloplasty (BAV), introduced since almost 20 years, has experienced a revival for its use in the treatment of elderly patients with severe calcified aortic stenosis that are associated with high operative risk and co-morbidities. This is due to the introduction of new balloon catheters and techniques. This study reports about 75 such cases performed within the past 28 months. The mean age of our patient group was 78 +/- 7 years (median = 80 years). Risk calculation with the EuroSCORE demonstrated an average value of 24.4 +/- 19.5%. BAV was performed along with burst pacing to reduce transvalvular blood flow for stabilization of the balloon catheter until blood pressure dropped to less than 50 mmHg. BAV was performed in 72 patients with a procedural success rate of 73%. There was a decrease of 31 mmHg peak-to-peak gradient across the aortic valve from 63 +/- 35 to 32 +/- 22 mmHg (P < 0.0001). Mean gradient was reduced from 51 +/- 24 to 27 +/- 15 mmHg (P < 0.0001). Aortic valve area increased by 49% from 0.84 +/- 0.33 to 1.25 +/- 0.45 cm(2) (P < 0.0001). Serious adverse events (SAE) occurred in 17% of the 75 BAV procedures. Follow-up revealed a significant improvement in 6-month and 1-year survival. The improved technology of BAV makes this technique attractive for elderly patients who are at high operative risk or in cases where valve replacement was refused for any reason.


Asunto(s)
Estenosis de la Válvula Aórtica/terapia , Calcinosis/complicaciones , Cardiomiopatías/complicaciones , Cateterismo/métodos , Anciano , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/etiología , Estenosis de la Válvula Aórtica/mortalidad , Calcinosis/mortalidad , Calcinosis/terapia , Cardiomiopatías/mortalidad , Cardiomiopatías/terapia , Femenino , Alemania/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Tasa de Supervivencia , Resultado del Tratamiento
10.
Herz ; 33(2): 129-35, 2008 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-18344032

RESUMEN

In contrast to chronic myocardial infarction, data concerning the value of cardiac magnetic resonance imaging in patients with acute onset of chest pain are still rare. Even in the presence of characteristic clinical parameters, cardiac magnetic resonance imaging might provide independent evidence especially in the absence of typical ECG alterations and prior to biomarker elevation. Besides the ability to demonstrate wall motion abnormalities cardiac magnetic resonance imaging gains additional potential as to the detection of myocardial edema, microvascular obstruction (no-reflow) and myocardial necrosis. However, cardiac magnetic resonance imaging is expensive and time-consuming, and therefore may not be cost-effective. At present, a lack of sufficient diagnostic and prognostic data would make cardiac magnetic resonance imaging unsuitable for routine stratification of chest pain patients in an emergency department.


Asunto(s)
Síndrome Coronario Agudo/diagnóstico , Angiografía Coronaria/métodos , Aumento de la Imagen/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Angiografía por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/métodos , Estenosis Coronaria/diagnóstico , Edema/diagnóstico , Electrocardiografía , Humanos , Miocardio/patología , Fenómeno de no Reflujo/diagnóstico , Sensibilidad y Especificidad
11.
Radiology ; 247(1): 106-14, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18292473

RESUMEN

PURPOSE: To prospectively compare in canines the diagnostic accuracy for myocardial infarction (MI) of standard delayed-enhancement (DE) magnetic resonance (MR) imaging versus that of subsecond DE MR imaging with and without breath holding and/or cardiac arrhythmia, with histologic findings or absence of surgical creation of MI as the reference standard. MATERIALS AND METHODS: This study was approved by the Institutional Animal Care and Use Committee; 21 canines were imaged with one standard and two subsecond DE MR techniques in four conditions: condition 1, breath holding and steady gating; 2, non-breath holding and steady gating; 3, breath holding and irregular heart rhythm; and 4, non-breath holding and irregular heart rhythm. Images were randomized and scored for diagnostic accuracy, image quality, and observer confidence. Sensitivity, specificity, and diagnostic accuracy for MI detection were calculated for each technique and clinical condition separately. The chi(2), paired t, and McNemar tests were used for comparisons. RESULTS: Fifteen dogs had MIs. Among conditions 2-4, differences were not significant (P > .05); data were pooled and referred to as group B. Condition 1 was group A. Accuracy, image quality, and observer confidence, respectively, for standard DE MR imaging were 96%, 3.7 +/- 0.8, and 2.7 +/- 0.6 in group A but only 74%, 2.4 +/- 0.8, and 1.8 +/- 0.7 in group B (P < or = .004 for each). Corresponding scores for subsecond techniques were unaffected by respiratory motion and/or arrhythmia. Subsecond techniques had higher accuracy (82% and 86% vs 74%), better image quality (3.9 +/- 0.7 and 3.2 +/- 0.8 vs 2.4 +/- 0.8), and greater confidence (2.4 +/- 0.7 and 2.1 +/- 0.7 vs 1.8 +/- 0.7) (P < or = .0002 for each) than standard DE MR imaging. In group A, standard performed better than subsecond DE MR imaging. CONCLUSION: Standard DE MR imaging is appropriate for MI detection with breath holding and regular heart rhythm, while subsecond techniques are appropriate with an irregular heart rhythm and when breath holding is not possible.


Asunto(s)
Arritmias Cardíacas/complicaciones , Imagen por Resonancia Magnética , Infarto del Miocardio/diagnóstico , Respiración , Animales , Perros , Imagen por Resonancia Magnética/métodos , Movimiento , Infarto del Miocardio/fisiopatología , Miocardio/patología , Intensificación de Imagen Radiográfica , Sensibilidad y Especificidad
12.
Int J Cardiol ; 128(2): 289-93, 2008 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-17698226

RESUMEN

In recent years, intravascular ultrasound (IVUS) has evolved as an important adjunct to angiography, providing insights that are significantly altering conventional paradigms in diagnosis and therapy. However, major drawbacks in the use of IVUS relied on the fact that a heavy console had to be moved from lab to lab, and extensive time for set up and image analysis. This additional time and the decrease in patients' through-put has not been applicable in clinical practice for many labs. Our manuscript concerns a novel PC-based platform for IVUS that enables the online intergration of digital intracoronary ultrasound images into angiographic images. This new technique offers remote operation, multiple control devices and custom viewing options. The PC-based platform enables IVUS images to be viewed simultaneously from multiple vantage points in the lab, and allows for multiple user interfaces.


Asunto(s)
Cateterismo Cardíaco , Procesamiento de Imagen Asistido por Computador , Integración de Sistemas , Ultrasonografía Intervencional , Humanos , Microcomputadores , Sistemas en Línea
13.
J Cardiovasc Magn Reson ; 9(5): 807-14, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17891619

RESUMEN

BACKGROUND: There is agreement that measurements of atrial volumes and ejection fraction (EF) are superior to atrial diameters for accurate determination of atrial size, follow up studies and prognosis. However, reference values for right atrial volumes and EF for cardiovascular magnetic resonance (CMR) have not been established but are crucial to identify patients with impaired right atrial function. METHODS AND RESULTS: Atrial function was studied in 70 healthy subjects (52+/-16 years, 38 male) with both the standard short axis method (SA) and the area-length method (AL) using steady-state free precession gradient-echo cine imaging (SSFP). Intraobserver, interobserver (n=70) and interstudy (n=10) variability was assessed for both methods. Maximal volumes, minimal volumes and EF for SA and AL were 101.0+/-30.2 mL, 50.3+/-19 mL and 47.2+/-8.3%, and 103.2+/-32.6 mL, 50.8+/-20.2 mL and 51.4+/-9.2%, respectively. Maximal volumes, minimal volumes and EF were higher with AL than with SA (mean difference: 2.2+/-4.6 mL, 3.5+/-3.5 mL and 2.8+/-2.8%, respectively). Atrial function measurements were not related to gender (p>or=0.387) and age (rho

Asunto(s)
Función del Atrio Derecho , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Cinemagnética , Adulto , Anciano , Femenino , Atrios Cardíacos/anatomía & histología , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Valores de Referencia , Reproducibilidad de los Resultados
14.
Magn Reson Med ; 58(1): 82-91, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17659624

RESUMEN

To extend the signal longevity of magnetically excited spins in flowing fluids while in a state of global coherent free precession (GCFP), a refocusing radiofrequency (RF) pulse and bipolar gradient waveforms were combined with the GCFP sequence. The data demonstrate that RF refocusing in the presence of flowing blood is possible, but the improvement in signal amplitude depends on the static magnetic field homogeneity along the direction of motion and the displacement of the spins between the excitation and the RF refocusing pulse, as well as displacement during subsequent RF refocusing pulses. The least amount of phase dispersion and thus the longest lasting signal is obtained with the shortest echo spacing where only one line of data is recorded between two RF refocusing pulses. This approach was successfully used in a phantom and in vivo to image fast and slow blood flow. Depending on the experimental conditions, signal persistence is improved significantly compared to playing the same sequence without RF refocusing, but the improvement is limited by the product of blood flow velocity and the time between RF refocusing pulses.


Asunto(s)
Angiografía por Resonancia Magnética/métodos , Animales , Perros , Fantasmas de Imagen
15.
Expert Rev Cardiovasc Ther ; 5(2): 307-21, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17338674

RESUMEN

Cardiovascular magnetic resonance (CMR) imaging is a comprehensive clinical tool for assessing a large variety of cardiovascular diseases. Using the clinical service of the Duke Cardiovascular Magnetic Resonance Center as an example, we describe how to perform image contractile function, myocardial perfusion at stress and rest, myocardial viability, cardiovascular morphology, vascular anatomy and blood flow tests. The emergence of successful dedicated CMR services presents an opportunity to optimize patient throughput by streamlining the user interface of CMR scanners, standardizing the viewing format and reporting software, and customizing training programs to focus on the standardized CMR approaches. Accordingly, we discuss potential pathways to create these standards. Finally, we discuss several promising new CMR techniques we expect will complement existing clinical procedures.


Asunto(s)
Enfermedades Cardiovasculares/diagnóstico , Angiografía por Resonancia Magnética/normas , Imagen por Resonancia Cinemagnética/normas , Intensificación de Imagen Radiográfica , Prueba de Esfuerzo/métodos , Femenino , Predicción , Humanos , Angiografía por Resonancia Magnética/tendencias , Imagen por Resonancia Magnética/normas , Imagen por Resonancia Magnética/tendencias , Imagen por Resonancia Cinemagnética/tendencias , Masculino , Sensibilidad y Especificidad
16.
Circulation ; 115(2): 236-44, 2007 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-17200443

RESUMEN

BACKGROUND: An ultrafast, delayed contrast-enhancement cardiovascular magnetic resonance technique that can acquire subsecond, "snapshot" images during free breathing (subsecond) is becoming widely available. This technique provides myocardial infarction (MI) imaging with complete left ventricular coverage in < 30 seconds. However, the accuracy of this technique is unknown. METHODS AND RESULTS: We prospectively compared subsecond imaging with routine breath-hold delayed contrast-enhancement cardiovascular magnetic resonance (standard) in consecutive patients. Two cohorts with unambiguous standards of truth were prespecified: (1) patients with documented prior MI (n=135) and (2) patients without MI and with low likelihood of coronary disease (lowest Framingham risk category; n=103). Scans were scored masked to identity and clinical information. Sensitivity, specificity, and accuracy of subsecond imaging for MI diagnosis were 87%, 96%, and 91%, respectively. Compared with the standard technique (98%, 100%, 99%), the subsecond technique had modestly reduced sensitivity (P=0.0001), but specificity was excellent. Missed infarcts were generally small or subendocardial (87%). Overall, regional transmural extent of infarction scores were highly concordant (2083/2294; 91%); however, 51 of 337 regions (15%) considered predominantly infarcted (> 50% transmural extent of infarction) by the standard technique were considered viable (< or = 25% transmural extent of infarction) by the subsecond technique. Quantitative analysis demonstrated moderately reduced contrast-to-noise ratios for subsecond imaging between infarct and remote myocardium (12.0+/-7.2 versus 20.1+/-6.6; P<0.0001) and infarct and left ventricular cavity (-2.5+/-2.7 versus 3.6+/-3.7; P<0.0001). CONCLUSIONS: MI can be rapidly detected by subsecond delayed contrast-enhancement cardiovascular magnetic resonance during free breathing with high accuracy. This technique could be considered the preferred approach in patients who are more acutely ill or unable to hold their breath. However, compared with standard imaging, sensitivity is mildly reduced, and the transmural extent of infarction may be underestimated.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Infarto del Miocardio/diagnóstico , Respiración , Adulto , Anciano , Estudios de Cohortes , Medios de Contraste , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico por imagen , Estudios Prospectivos , Radiografía , Mecánica Respiratoria/fisiología , Factores de Tiempo
17.
Am Heart J ; 150(4): 737-42, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16209976

RESUMEN

PURPOSE: The aim of this study was to compare the visual and quantitative assessment for left ventricular ejection fraction (LVEF) in normal subjects and patients with impaired LV function. METHODS: One hundred subjects (40 normal subjects, 40 patients with ischemic cardiomyopathy, and 20 patients with nonischemic cardiomyopathy) were investigated using a 1.5-T cardiovascular magnetic resonance imager. Images were acquired by a fast gradient-echo sequence with steady-state free precession using the standard short-axis method. Left ventricular EF was calculated from the sums of the outlined areas using the Simpson rule. Interobserver variability between the calculated and the visual EF was assessed. Analyses were performed randomly and blinded by 2 independent observers. RESULTS: Left ventricular EF was significantly underestimated by the visual read in all 3 groups (mean difference: normal subjects -2.6% +/- 2.6%, ischemic cardiomyopathy -1.7% +/- 2.1%, and nonischemic cardiomyopathy -1.2% +/- 2.1%; P < or = .02). The difference was larger in normal subjects than in patients with cardiomyopathy (P = .04). The interobserver variability was smaller for the quantitative assessment than for the visual estimation. CONCLUSION: Left ventricular EF is underestimated by visual estimation compared with the quantitative assessment. The visual approach for EF assessment may be used for rapid assessment of left ventricular function in clinical practice where accuracy is of less concern. For most accurate analysis, the quantitative standard short axis approach is required.


Asunto(s)
Imagen por Resonancia Magnética , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/fisiopatología , Volumen Sistólico , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
18.
J Cardiovasc Magn Reson ; 7(4): 677-83, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16136858

RESUMEN

BACKGROUND: Because cardiovascular magnetic resonance imaging (CMR) is becoming increasingly available in clinical practice, there is a need to establish normal values for left atrial dimensions as determined by this method to allow accurate assessment of cardiac dimensions and to provide standardization for follow up studies. For clinical purpose measurements of the left atrial end diastolic diameter (LAEDD) are most appropriate to assess left atrial size. We aimed to establish normal values for LAEDD using CMR and a fast gradient-echo sequence with steady-state free precession (SSFP). METHODS: A total of 111 healthy subjects (52 women and 59 men, mean age 51.5 +/- 14.5 years) were examined by CMR. Images were acquired using SSFP in the horizontal (HLA) and vertical (VLA) long axis planes and the left ventricular outflow tract plane (LVOT) to measure the LAEDD. RESULTS: Age between men and women was not different (p = 0.7050). CMR yielded the following normal ranges for LAEDD: HLA 4.5 +/- 0.4 cm for men and 4.2 +/- 0.5 for women, VLA 4.5 +/- 0.5 cm for men and 4.2 +/- 0.4 for women, and LVOT 2.8 +/- 0.3 cm for men and 2.8 +/- 0.4 for women. LAEDD were significantly larger in HLA and VLA than in LVOT (p < or = 0.0001). There was no significant difference in the measurements between HLA and VLA (p = 0.4617). Gender-related differences for LAEDD were found in HLA (p = 0.0087) and VLA (p = 0.0015) but not in LVOT (p = 0.5281). LAEDD were not found to be age-related (p > or = 0.0994). CONCLUSIONS: LAEDD differ significantly according to the image plane. We provide reference values for CMR using prospective triggering in the evaluation of left atrial diameters to identify patients with enlarged left atria and for follow-up studies.


Asunto(s)
Atrios Cardíacos/anatomía & histología , Imagen por Resonancia Magnética , Adulto , Factores de Edad , Anciano , Función Atrial , Superficie Corporal , Ecocardiografía , Femenino , Atrios Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/anatomía & histología , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Estudios Prospectivos , Valores de Referencia , Caracteres Sexuales , Volumen Sistólico , Función Ventricular Izquierda
19.
J Cardiovasc Magn Reson ; 7(3): 587-93, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15959972

RESUMEN

PURPOSE: Most magnetic resonance imaging (MRI) centers currently use prospective electrocardiographic (ECG) triggering for image acquisition. Retrospectively gated sequences allow the coverage of the entire cardiac cycle. It has been recently shown that ventricular volumes and ejection fraction (EF) differ according to the gating method used for image acquisition. The authors sought to evaluate how much measurements of atrial volumes and EF differ depending on the gating method. MATERIALS AND METHODS: Eighteen subjects with no cardiovascular disease were investigated by MRI using a 1.5 Tesla scanner. Images were acquired with a gradient-echo sequence with steady-state free precession (SSFP) using the standard short-axis method for volume and EF measurements. Images were acquired with 6 mm thick slices using both prospective triggering and retrospective gating. Left and right atrial volumes (end diastolic volume [EDV]; end systolic volume [ESV]; stroke volume [SV]) and EF were determined with a commercially available software package. RESULTS: ESV was significantly smaller with the retrospectively gated SSFP sequence than with the prospectively triggered sequence (mean difference: ESV left 3.97 +/- 1.3 ml, p < 0.0001; ESV right 4.34 +/- 1.8 ml, p < 0.0001). EF and SV were significantly smaller with prospective triggering (mean difference: EF left -5.94 +/- 0.9%, p < 0.0001; EF right -5.52 +/- 1.3 %, p < 0.0001; SV left -3.99 +/- 1.3 ml, p < 0.0001; SV right -4.32 +/- 1.9 ml, p < 0.0001). EDV remained unchanged (mean difference: EDV left -0.03 +/- 0.8 ml, p = 0.902; right EDV 0.04 +/- 0.7 ml, p = 0.882). CONCLUSION: The gating method has a significant impact on atrial volume and EF measurements. Atrial EF is underestimated by using the prospective triggering technique.


Asunto(s)
Volumen Cardíaco , Electrocardiografía/métodos , Atrios Cardíacos/patología , Imagen por Resonancia Cinemagnética , Volumen Sistólico , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sístole
20.
J Cardiovasc Magn Reson ; 7(2): 441-6, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15881527

RESUMEN

PURPOSE: Most MRI centers currently use prospective ECG triggering and fast gradient-echo sequences for image acquisition. Retrospectively gated sequences allow the coverage of the entire cardiac cycle. There is concern about whether ventricular volumes and ejection fraction (EF) differ according to the gating method used for image acquisition. We sought to evaluate the impact of the gating method on measurements of right and left ventricular volumes and EF in normal subjects. MATERIALS AND METHODS: Fifteen subjects with no cardiovascular disease were investigated by MRI using a 1.5 Tesla scanner. Images were acquired with a gradient-echo sequence with steady-state free precession (SSFP) using the standard short-axis method for volume and EF measurements. Images were acquired with 6-mn-thick slices using both prospective triggering and retrospective gating. Left and right ventricular volumes (EDV, ESV, SV) and EF were determined with a commercially available software package (Argus, Siemens). RESULTS: EDV and SV calculated from short-axis images were significantly smaller with the prospectively triggered SSFP sequence (mean difference: EDV left: 13.9 +/- 4.4 mL, p < 0.0001; SV left: 13.5 +/- 4.8 mL, p < 0.0001; EDV right: 14.2 +/- 3.9 mL, p < 0.0001; SV right: 14.7 +/- 5.9 mL, p < 0.0001). EF was significantly smaller for the right ventricle (mean difference -3.6 +/- 3.3%, p = 0.0008) and the left ventricle (mean difference -2.3 +/- 3.3%, p = 0.02). ESV remained unchanged (mean difference: ESV left: 0.47 +/- 3.5 mL, p = 0.6179; right ESV: 0.5 +/- 3.7 mL, p = 0.6083). CONCLUSION: The gating method has a significant impact on volume and EF measurements. The global ventricular EF is underestimated by using the prospective triggering technique. However, the difference in the left ventricle is small and might not be of clinical relevance.


Asunto(s)
Gasto Cardíaco/fisiología , Ventrículos Cardíacos/patología , Imagen por Resonancia Cinemagnética/métodos , Diástole/fisiología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Estudios Prospectivos , Sístole/fisiología
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