Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
3.
Med Klin Intensivmed Notfmed ; 113(5): 426-429, 2018 06.
Artículo en Alemán | MEDLINE | ID: mdl-28852773

RESUMEN

We report on a 49-year-old fitness trainer, who was admitted to our hospital after cardiac arrest due to ventricular fibrillation. Return of spontaneous circulation was achieved after immediate cardiopulmonary resuscitation. Coronary angiography could exclude coronary artery disease. Echocardiography demonstrated the presence of apical hypertrophic cardiomyopathy, associated with cor triatriatum sinister. Cardiac magnetic resonance imaging additionally showed marked myocardial fibrosis. The patient underwent placement of an implantable cardioverter-defibrillator and was subsequently discharged for rehabilitation in good condition.


Asunto(s)
Cardiomiopatía Hipertrófica , Corazón Triatrial , Desfibriladores Implantables , Paro Cardíaco , Atletas , Cardiomiopatía Hipertrófica/complicaciones , Corazón Triatrial/complicaciones , Ecocardiografía , Paro Cardíaco/etiología , Paro Cardíaco/terapia , Humanos , Persona de Mediana Edad
4.
Rofo ; 186(3): 267-73, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24043613

RESUMEN

PURPOSE: The purpose of this study was to find out whether pneumothorax detection and exclusion is superior in expiratory digital chest radiography. MATERIALS AND METHODS: 131 patients with pneumothorax with paired inspiratory and expiratory chest radiographs were analyzed regarding localization and size of pneumothorax. Sensitivity, specificity, negative (npv) and positive predictive value (ppv) as well as the positive (LR+) and negative likelihood ratio (LR-) were determined in a blinded randomized interobserver study with 116 patients. The evaluation was performed by three board-certified radiologists. RESULTS: In 131 patients, there were 139 pneumothoraces, 135 (97.1 %) were located apical, 88 (63.3 %) lateral and 33 (23.7 %) basal. Sensitivity was 99 % for inspiratory and 97 % for expiratory radiographs. The interobserver study yielded a mean sensitivity of 86.1 %/86.1 %, specificity of 97.3 %/93.4 %, npv of 88.7 %/88.5 % and ppv of 96.7 %/92.1 % for inspiration/expiration. For inspiratory radiographs the LR+/LR- were 40.2/0.14 and for expiration 13.9 and 0.15. McNemar-Test showed no significant difference for the detection of pneumothoraces in in-/exspiration. CONCLUSION: Inspiratory and expiratory digital radiographs are equally suitable for pneumothorax detection. Inspiratory radiographs are recommended as the initial examination of choice for pneumothorax detection, an additional expiratory radiograph is only recommended in doubtful cases. KEY POINTS: • Basal pneumothoraces during inspiration demonstrate a greater width than during expiration. • There is statistically no difference between inspiration/expiration for the diagnosis of pneumothorax. • An image taken during inspiration is recommended to confirm or rule out a pneumothorax.


Asunto(s)
Espiración , Inhalación , Neumotórax/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía Torácica/estadística & datos numéricos , Adolescente , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto Joven
5.
Rofo ; 183(9): 834-41, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21830182

RESUMEN

PURPOSE: The aim of this study was to evaluate a comprehensive cardiac magnetic resonance (MR) imaging approach in patients with peripartum cardiomyopathy (PPCM). The focus was on inflammatory myocardial changes. MATERIALS AND METHODS: Retrospective analysis of 12 cardiac MR examinations was performed in 6 patients with PPCM. The protocol comprised cine sequences for the determination of chamber sizes and function. T 2-weighted sequences for determination of edema (T 2 ratio), T 1-weighted images for measurement of early gadolinium enhancement ratio (EGER), and late gadolinium enhancement (LGE) sequences were used for tissue characterization. 5 examinations were performed during the acute stage, and 7 examinations were performed during the course of the disease. RESULTS: Initially, 3 of 5 patients presented with an elevated left ventricular end-diastolic volume (LVEDV); in one patient, the LVEDV was in the upper range. In 4 of 5 subjects, the left ventricular ejection fraction (LVEF) was decreased. The T 2 ratio and EGER values were initially elevated in all women. No LGE was detected in initial scans. In follow-up examinations, the LVEDV decreased and the LVEF increased in all patients. Tissue-characterizing parameters decreased to normal in all but 1 patient. 2 patients showing LGE did not present a favorable clinical course. CONCLUSION: Myocardial inflammation was detected in the acute stage of PPCM, which was mostly transient. In our small group, patients showing LGE had a non-favorable clinical course. Future studies should include tissue-characterizing parameters, such as T 2 ratio and EGER. Thus, further insights into pathophysiology can be gained and therapeutic effects can be measured in a more extensive manner.


Asunto(s)
Cardiomiopatías/diagnóstico , Aumento de la Imagen/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Cinemagnética/métodos , Imagen por Resonancia Magnética/métodos , Complicaciones Cardiovasculares del Embarazo/diagnóstico , Trastornos Puerperales/diagnóstico , Enfermedad Aguda , Adulto , Medios de Contraste/administración & dosificación , Femenino , Estudios de Seguimiento , Gadolinio DTPA , Atrios Cardíacos/patología , Insuficiencia Cardíaca/diagnóstico , Ventrículos Cardíacos/patología , Humanos , Hipertrofia Ventricular Izquierda/diagnóstico , Miocardio/patología , Periodo Periparto , Embarazo , Valores de Referencia , Estudios Retrospectivos , Volumen Sistólico/fisiología , Adulto Joven
7.
Rofo ; 181(8): 800-14, 2009 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-19621277

RESUMEN

MRI and CT have become important tools in the diagnosis of cardiac diseases. The permanent technical development and the continuously growing clinical and scientific experience required an update of the previous recommendations regarding the spectrum of clinical applications and the technical aspects of MRI and CT of the heart. The Working group Herzdiagnostik of the German Roentgen Society has revised its recommendations based on the current literature and has updated technical requirements and clinical indications. Part I of the recommendations deals with cardiac computed tomography while part II focuses on MRI in cardiac applications. These recommendations shall serve as a guideline when deciding on appropriate technique for non-invasive cardiac imaging and shall help to perform high quality imaging based on a standardised approach.


Asunto(s)
Cardiopatías/diagnóstico , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Técnicas de Imagen Sincronizada Cardíacas/instrumentación , Medios de Contraste/administración & dosificación , Angiografía Coronaria/métodos , Diagnóstico Diferencial , Prueba de Esfuerzo , Hemodinámica/fisiología , Humanos , Procesamiento de Imagen Asistido por Computador/instrumentación , Angiografía por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/instrumentación , Sensibilidad y Especificidad
8.
Rofo ; 181(7): 700-6, 2009 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-19554489

RESUMEN

MRI and CT have become important tools in the diagnosis of cardiac diseases. The permanent technical development and the continuously growing clinical and scientific experience required an update of the previous recommendations regarding the spectrum of clinical applications and the technical aspects of MRI and CT of the heart. The Working group Herzdiagnostik of the German Roentgen Society has revised its recommendations based on the current literature and has updated technical requirements and clinical indications. Part I of the recommendations deals with cardiac computed tomography while part II focuses on MRI in cardiac applications. These recommendations shall serve as a guideline when deciding on appropriate technique for non-invasive cardiac imaging and shall help to perform high quality imaging based on a standardised approach.


Asunto(s)
Electrocardiografía/métodos , Cardiopatías/diagnóstico , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada por Rayos X/métodos , Calcinosis/diagnóstico , Cardiomiopatías/diagnóstico , Angiografía Coronaria/métodos , Enfermedad Coronaria/diagnóstico , Estenosis Coronaria/diagnóstico , Cardiopatías Congénitas/diagnóstico , Enfermedades de las Válvulas Cardíacas/diagnóstico , Humanos , Isquemia Miocárdica/diagnóstico , Pericardio/patología , Venas Pulmonares/patología , Garantía de la Calidad de Atención de Salud , Sensibilidad y Especificidad , Disfunción Ventricular/diagnóstico
10.
Acta Radiol ; 47(9): 899-906, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17077038

RESUMEN

PURPOSE: To evaluate several substances regarding small bowel distension and contrast on balanced steady-state free precession (bSSFP) cine magnetic resonance (MR) images. MATERIAL AND METHODS: Luminal contrast was evaluated in 24 volunteers after oral application of two different contrast agent groups leading to either bright lumen (pineapple, blueberry juice) or dark lumen (tap water, orange juice) on T1-weighted images. Bowel distension was evaluated in 30 patients ingesting either methylcellulose or mannitol solution for limiting intestinal absorption. Fifteen patients with duodeno-jejunal intubation served as the control. Quantitative evaluation included measurement of luminal signal intensities and diameters of four bowel segments, qualitative evaluation assessed luminal contrast and distension on a five-point scale. RESULTS: Quantitative and qualitative evaluation of the four contrast agents revealed no significant differences regarding luminal contrast on bSSFP images. Quantitative evaluation revealed significantly lower (P<0.05) small bowel distension for three out of four segments (qualitative evaluation: two out of four segments) for methylcellulose in comparison to the control. Mannitol was found to be equal to the control. CONCLUSION: Oral ingestion of tap water or orange juice in combination with mannitol is recommended for cine MR imaging of the small bowel regarding luminal contrast and small bowel distension on bSSFP sequences.


Asunto(s)
Medios de Contraste/administración & dosificación , Intestino Delgado/patología , Imagen por Resonancia Cinemagnética , Administración Oral , Adolescente , Adulto , Anciano , Femenino , Humanos , Imagen por Resonancia Cinemagnética/métodos , Masculino , Persona de Mediana Edad
11.
Rofo ; 177(7): 946-54, 2005 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-15973596

RESUMEN

The treatment of advanced, drug resistant congestive heart failure gains in importance in the field of cardiac surgery. Cardiac imaging for preoperative assessment and follow-up focuses on the determination of ventricular volumes and function as well as on the detection of postoperative complications. Computed tomography (CT) is highly accurate irrespective of the individual patient's anatomic situation, has a low examiner dependence and short examination time, does not require an arterial vascular access and can be performed in patients with metal implants. CT is the modality of choice in the follow-up of heart transplants to detect extracardiac and cardiac complications including coronary calcifications as an early sign of transplant vasculopathy. In addition, CT visualizes the elements of mechanical assist devices and can identify their possible local cardiac and mediastinal complications. CT can detect fibrolipomatous involution of the mobilized muscle flap in dynamic cardiomyoplasty and can depict fibrous reactions along the epicardial mesh implant in passive cardiac containment. Further indications include assessment of typical local postoperative complications, such as intrathoracic infection and mediastinal bleeding, intracardiac thrombus formation or pericardial effusion. CT is routinely used for evaluating bypass patency but is limited in assessing associated valve defects since it does not visualize flow.


Asunto(s)
Procedimientos Quirúrgicos Cardiovasculares/métodos , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/cirugía , Cuidados Posoperatorios/métodos , Cuidados Preoperatorios/métodos , Cirugía Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Ensayos Clínicos como Asunto , Humanos , Guías de Práctica Clínica como Asunto , Pautas de la Práctica en Medicina , Pronóstico , Medición de Riesgo/métodos , Factores de Riesgo , Resultado del Tratamiento
12.
Rofo ; 176(9): 1237-44, 2004 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-15346257

RESUMEN

PURPOSE: To compare the visual analysis of magnetic resonance imaging (MRI) with the tagging technique and Doppler tissue echocardiography with invasive ventriculography in detecting and quantifying regional left ventricular wall motion abnormalities. MATERIALS AND METHODS: Sixteen patients with coronary artery disease and a history of prior myocardial infarction underwent invasive ventriculography, Doppler tissue echocardiography and MR-tagging within one week. Regional wall motion abnormalities (WMA) were detected in all patients. WMA were graded as normal = 1; hypokinetic = 2; akinetic = 3; or dyskinetic = 4. For agreement between MRI, echocardiography, and ventriculography the kappa coefficient (kappa) according to Cohen was calculated. RESULTS: The kappa coefficient (kappa) was 0.962 for agreement between MRI and echocardiography and 0.602 for agreement between MRI and ventriculography as well as between echocardiography and ventriculography. CONCLUSION: Reliable analysis of regional left ventricular wall motion abnormalities is feasible using visual analysis of MR-tagging. MRI and Doppler tissue echocardiography detect more WMA than invasive ventriculography and grade them as more severe.


Asunto(s)
Enfermedad Coronaria/diagnóstico , Ecocardiografía Doppler , Corazón/fisiopatología , Imagen por Resonancia Cinemagnética/métodos , Anciano , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/fisiopatología , Diástole , Electrocardiografía , Femenino , Frecuencia Cardíaca , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Contracción Miocárdica , Análisis de Regresión , Sensibilidad y Especificidad , Sístole , Ultrasonografía Doppler en Color
13.
Z Kardiol ; 92(11): 953-6, 2003 Nov.
Artículo en Alemán | MEDLINE | ID: mdl-14634765

RESUMEN

We report about a woman with a rare complication after mitral valve replacement 24 years ago. The patient had a massive hemorrhage some hours after operation. We performed invasive diagnostics because of an increasing pressure gradient across the prosthesis and revealed a left ventricular pseudoaneurysm. Before the planned reoperation the patient died suddenly. As the cause of death, we assumed a rupture of the pseudoaneurysm.


Asunto(s)
Aneurisma Falso/etiología , Endocarditis Bacteriana/cirugía , Aneurisma Cardíaco/etiología , Rotura Cardíaca/etiología , Implantación de Prótesis de Válvulas Cardíacas , Insuficiencia de la Válvula Mitral/cirugía , Complicaciones Posoperatorias/etiología , Adulto , Aneurisma Falso/diagnóstico , Angiocardiografía , Ecocardiografía , Resultado Fatal , Femenino , Aneurisma Cardíaco/diagnóstico , Rotura Cardíaca/diagnóstico , Humanos , Complicaciones Posoperatorias/diagnóstico , Hemorragia Posoperatoria/diagnóstico , Hemorragia Posoperatoria/etiología
14.
Heart ; 89(8): e21, 2003 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12860887

RESUMEN

This is the first description of a case of isolated non-compaction of the left ventricular myocardium, involving a 52 year old woman presenting with progressive heart failure, with analysis of myocardial perfusion by contrast echocardiography in comparison with magnetic resonance imaging.


Asunto(s)
Cardiomiopatía Dilatada/etiología , Insuficiencia Cardíaca/etiología , Cardiomiopatía Dilatada/diagnóstico , Vasos Coronarios , Ecocardiografía/métodos , Femenino , Insuficiencia Cardíaca/diagnóstico , Humanos , Angiografía por Resonancia Magnética , Persona de Mediana Edad
15.
Rofo ; 175(8): 1086-92, 2003 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-12886477

RESUMEN

PURPOSE: To evaluate the efficacy of passive cardiomyoplasty with the determination of biventricular volumes, global systolic function as well as left-ventricular muscle mass. MATERIALS AND METHODS: In 19 patients with congestive heart failure of idiopathic or ischemic origin, a polyester mesh-graft was implanted around both ventricles for stabilization and functional support. Before and three months after surgery, 15 patients underwent EBCT and 4 patients with impaired renal function underwent MRI, for the evaluation of the volume and ejection fraction of both ventricles. RESULTS: EBCT demonstrated a decrease from 385 to 310 ml in LV-EDV, from 312 to 242 ml in LV-ESV, from 209 to 160 ml in RV-EDV and from 149 to 87 ml in RV-ESV, and an increase from 20 to 26% in LV-EF and from 37 to 50% in RV-EF as well as a reduction of LV-MM from 300 to 274 g (p < 0.05 each). Similar results were obtained by MRI. CONCLUSION: Following passive cardiomyoplasty, EBCT and MRI revealed an improvement of the global systolic function as well as a reduction of biventricular volumes and left-ventricular muscle mass.


Asunto(s)
Volumen Cardíaco/fisiología , Cardiomiopatía Dilatada/cirugía , Enfermedad Coronaria/cirugía , Insuficiencia Cardíaca/cirugía , Imagen por Resonancia Cinemagnética , Complicaciones Posoperatorias/diagnóstico , Tomografía Computarizada por Rayos X , Disfunción Ventricular Izquierda/cirugía , Disfunción Ventricular Derecha/cirugía , Adulto , Anciano , Cardiomiopatía Dilatada/diagnóstico , Cardiomiopatía Dilatada/fisiopatología , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/fisiopatología , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/fisiopatología , Ventrículos Cardíacos/cirugía , Hemodinámica/fisiología , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/fisiopatología , Estudios Prospectivos , Implantación de Prótesis , Mallas Quirúrgicas , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/fisiopatología , Disfunción Ventricular Derecha/diagnóstico , Disfunción Ventricular Derecha/fisiopatología
16.
Rofo ; 175(6): 822-9, 2003 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-12811696

RESUMEN

AIM: To investigate the signal-enhancing effects of the macromolecular contrast medium Gadomer in MR angiography of the coronary arteries compared to Gd-DTPA. MATERIAL AND METHODS: A total of 15 MRI examinations of the heart were performed in pigs at 1.5 T using a pulse-triggered, segmented 3D FLASH sequence with data acquisition during breathhold before and up to 30 min after contrast medium injection. Gadomer was investigated at two doses (0.05 and 0.1 mmol Gd/kg), Gd-DTPA at one (0.3 mmol Gd/kg) (n = 5 examinations per dose). Standard sequences without magnetization preparation were supplemented by sequences with magnetization saturation applied before data acquisition before and immediately after contrast medium injection. Analysis comprised quantitative determination of blood and myocardium signal to noise (S/N) and contrast to noise (C/N) and qualitative assessment of several parameters of image quality and coronary artery visualization. RESULTS: Gadomer leads to a significant C/N increase between blood and myocardium compared to the unenhanced examination and the increase is longer-lasting than that produced by Gd-DTPA (Gd-DTPA: only directly after injection; Gadomer: up to 5 min post injection at 0.05 mmol Gd/kg, up to 10 min at 0.1 mmol Gd/kg). The qualitative evaluation shows that visualization of the coronary arteries and branch vessels is significantly better with Gadomer at both doses than with Gd-DTPA. Magnetization saturation increases the C/N in combination with Gd-DTPA and at the higher dose of Gadomer with the latter producing a higher increase in C/N values. CONCLUSION: Gadomer is a suitable contrast medium for MR angiography of the coronary arteries with the dose of 0.1 mmol Gd/kg being superior to 0.05 mmol Gd/kg due to a longer imaging window.


Asunto(s)
Medios de Contraste/administración & dosificación , Enfermedad Coronaria/diagnóstico , Vasos Coronarios/patología , Gadolinio DTPA , Gadolinio , Angiografía por Resonancia Magnética/métodos , Animales , Artefactos , Medios de Contraste/farmacocinética , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Gadolinio/farmacocinética , Gadolinio DTPA/farmacocinética , Inyecciones Intravenosas , Tasa de Depuración Metabólica/fisiología , Sensibilidad y Especificidad , Porcinos , Porcinos Enanos
17.
Acta Radiol ; 44(2): 172-6, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12694104

RESUMEN

PURPOSE: To evaluate the capability of bright-blood cine MR to directly visualize the leaflets of the valve replacement in pulmonary position following Ross operation. MATERIAL AND METHODS: Long and short axis views of the pulmonary valve were obtained in 10 normal subjects and 14 patients after Ross operation. Valve morphology and function were analyzed and signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were calculated. Flow measurements were performed in the pulmonary trunk to assess pulmonary regurgitation. RESULTS: In all subjects, tricuspid morphology of the pulmonary valve was visualized. SNR of the leaflets in normal subjects (9.8 +/- 3.0) and in patients after Ross operation (7.5 +/- 2.2) differed significantly from blood (12.6 +/- 3.2 and 11.3 +/- 2.5, respectively, p < 0.05). Valvular regurgitation was seen in 5 patients as an insufficient closure of the valve which was confirmed by flow measurements. CONCLUSION: Cine MR enables in-plane visualization of the pulmonary valve and allows for functional and morphological evaluation in patients after pulmonary valve surgery.


Asunto(s)
Imagen por Resonancia Cinemagnética , Válvula Pulmonar/anatomía & histología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
19.
Acta Radiol ; 42(6): 560-2, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11736701

RESUMEN

PURPOSE: We present a protocol for the non-invasive angiographic assessment of the arterial and venous cerebrovascular (CV) system by multi-slice CT. MATERIAL AND METHODS: Data acquisition was performed in a multi-slice CT scanner with a scan range from the carotid bifurcation to the vertex and manual scan start following i.v. administration of 120 ml iodinated contrast medium with a flow rate of 4 ml/s. This protocol was applied in 12 patients with symptoms of acute CV insuffiency. RESULTS: In all patients, comprehensive imaging of the arteriovenous CV system was achieved including the common carotid bifurcation, the third segment of the major cerebral arteries, the dural sinus and the internal cerebral veins. Various CV pathologies, such as a territorial artery occlusion, a thrombotic obstruction of the internal carotid artery, an intracranial arteriovenous malformation and a sinus vein thrombosis, were successfully evaluated. CONCLUSION: Comprehensive assessment of the arteriovenous CV system is possible by the use of a single-bolus, monophasic multi-slice scan technique.


Asunto(s)
Arterias Cerebrales/diagnóstico por imagen , Venas Cerebrales/diagnóstico por imagen , Trastornos Cerebrovasculares/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Angiografía Cerebral/métodos , Arterias Cerebrales/fisiopatología , Venas Cerebrales/fisiopatología , Circulación Cerebrovascular/fisiología , Trastornos Cerebrovasculares/fisiopatología , Protocolos Clínicos , Medios de Contraste/administración & dosificación , Femenino , Humanos , Inyecciones Intravenosas , Masculino , Persona de Mediana Edad , Tomógrafos Computarizados por Rayos X
20.
Invest Radiol ; 36(11): 625-31, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11606839

RESUMEN

RATIONALE AND OBJECTIVES: Magnetic resonance (MR) is limited by artifacts in vessels after stenting. An active MR imaging stent (AMRIS) allows for artifact-free imaging with local improvement in signal-to-noise ratio (SNR). In a rabbit model, we evaluated the imaging properties by MR angiography (MRA) and flow measurements. METHODS: The AMRIS was placed in the abdominal aorta of five rabbits. At 1.5 T, MRA (three-dimensional fast low-angle shot) was performed before and after intravenous injection of an iron oxide-based, blood-pool contrast medium (dose, 50 micromol Fe/kg), and flow measurements were performed (electrocardiographically triggered phase-contrast cine gradient-echo sequence). Mean SNRs were calculated and flow volume curves were generated. RESULTS: The SNR was 6.0 +/- 0.6 (outside the stent) versus 12.3 +/- 1.1 (inside the stent, P < 0.05) for plain MRA, 21.2 +/- 0.6 versus 40.6 +/- 5.2 (P < 0.05) for contrast-enhanced MRA, and 5.4 +/- 0.4 versus 13.7 +/- 2.1 (P < 0.05) for the magnitude images of flow measurements. Flow volume curves within and distal to the stent were comparable. CONCLUSIONS: By using the AMRIS as a vascular stent, the stented vessel segment can be examined with enhanced signal intensity on MRI.


Asunto(s)
Aorta Abdominal/patología , Angiografía por Resonancia Magnética/métodos , Stents , Animales , Aorta Abdominal/cirugía , Artefactos , Velocidad del Flujo Sanguíneo , Medios de Contraste/administración & dosificación , Compuestos Férricos , Óxido Ferrosoférrico , Inyecciones Intravenosas , Masculino , Conejos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA