RESUMEN
Sonoelastography combines elastography and B mode ultrasonography to show parameters related to the structural organization of tissues in real time. Thus, this noninvasive technique shows us the mechanical characteristics of each tissue. The different elastography techniques (qualitative and quantitative, in ultrasonography or magnetic resonance imaging) are based on the hypothesis that soft tissues are more deformable than stiff tissues and that these differences can be captured in images. Elastography adds a new perspective to conventional ultrasonography: it reflects the stiffness of the tissues, and this information, together with the anatomic information from B mode imaging and the vascular information from Doppler, is key for the diagnosis. This article aims to provide a brief summary of what elastography is, the different types of elastography, and the range of possible applications of this technique.
Asunto(s)
Diagnóstico por Imagen de Elasticidad , Diagnóstico por Imagen de Elasticidad/métodos , HumanosRESUMEN
OBJECTIVE: To investigate the utility of acoustic radiation force impulse (ARFI) imaging, with the determination of shear wave velocity (SWV), to differentiate non-alcoholic fatty liver disease (NAFLD) from non-alcoholic steatohepatitis (NASH) in patients with morbid obesity before bariatric surgery. METHODS: Thirty-two patients with morbid obesity were evaluated with ARFI and conventional ultrasound before bariatric surgery. The ARFI and ultrasound results were compared with liver biopsy findings, which is the reference standard. The patients were classed according to their histological findings into three groups: group A, simple steatosis; group B, inflammation; and group C, fibrosis. RESULTS: The median SWV was 1.57 ± 0.79 m/s. Hepatic alterations were observed in the histopathological findings for all the patients in the study (100 %), with the results of the laboratory tests proving normal. Differences in SWV were also observed between groups A, B and C: 1.34 ± 0.90 m/s, 1.55 ± 0.79 m/s and 1.86 ± 0.75 m/s (P < 0.001), respectively. The Az for differentiating NAFLD from NASH or fibrosis was 0.899 (optimal cut-off value 1.3 m/s; sensitivity 85 %; specificity 83.3 %). CONCLUSION: The ARFI technique is a useful diagnostic tool for differentiating NAFLD from NASH in asymptomatic patients with morbid obesity. KEY POINTS : ⢠Acoustic radiation force impulse imaging provides ultrasonic shear wave velocity measurements. ⢠SWV measurements were higher in patients with inflammation or fibrosis than NAFLD. ⢠ARFI differentiates NAFLD from NASH in patients with morbid obesity. ⢠Results suggest that ARFI can detect NASH in asymptomatic morbidly obese patients.
Asunto(s)
Cirugía Bariátrica/métodos , Hígado Graso/complicaciones , Hígado Graso/diagnóstico , Obesidad Mórbida/complicaciones , Ultrasonografía/métodos , Acústica , Adulto , Biopsia , Femenino , Humanos , Inflamación , Hígado/diagnóstico por imagen , Hígado/fisiopatología , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico , Estudios Prospectivos , Curva ROC , Estándares de Referencia , Reproducibilidad de los Resultados , Resistencia al Corte , Estrés MecánicoRESUMEN
La elastosonografía es el resultado de la conjunción entre la elastografía y la ecografía en modo-B, donde se muestran, en tiempo real, los parámetros relativos a la organización estructural de los tejidos. De esta manera, vemos reflejadas, en una técnica no invasiva, las características mecánicas de cada tejido. Las diferentes técnicas de elastografía (cualitativas y cuantitativas en ultrasonido o resonancia magnética) se basan en la hipótesis de que los tejidos blandos se deforman más que los rígidos y que estas diferencias pueden ser plasmadas en imágenes. La elastografía aporta una nueva perspectiva a la ecografía convencional: la rigidez de los tejidos que junto con la información anatómica del modo-B y la vascular del modo-Doppler proporciona una información clave para el diagnóstico. En este artículo se pretende realizar un pequeño resumen de lo que es la elastografía, los tipos que existen, y el abanico de posibilidades que nos ofrece (AU)
Sonoelastography combines elastography and B mode ultrasonography to show parameters related to the structural organization of tissues in real time. Thus, this noninvasive technique shows us the mechanical characteristics of each tissue. The different elastography techniques (qualitative and quantitative, in ultrasonography or magnetic resonance imaging) are based on the hypothesis that soft tissues are more deformable than stiff tissues and that these differences can be captured in images. Elastography adds a new perspective to conventional ultrasonography: it reflects the stiffness of the tissues, and this information, together with the anatomic information from B mode imaging and the vascular information from Doppler, is key for the diagnosis. This article aims to provide a brief summary of what elastography is, the different types of elastography, and the range of possible applications of this technique (AU)