RESUMEN
After it was reported that increased tissue iron concentrations were associated with increased echogenicity of the substantia nigra (SN) obtained with transcranial sonography (TCS) in animal and postmortem studies, our goal was to use this method in a disorder characterized with iron accumulation in human brain tissue. Therefore, magnetic resonance imaging (MRI) and TCS were conducted in 5 unrelated patients with pantothenate kinase-associated neurodegeneration (PKAN), caused by PANK2 mutations. All patients had an eye of the tiger sign. Hypointense lesions on the T2-weighted MRI images were restricted to the globus pallidus (GP) and SN. TCS also revealed bilateral hyperechogenicity restricted to the LN and SN, with normal DTV values. Both TCS and MRI studies in PKAN patients are in accordance with the pathological findings that accumulation of iron, even in advanced cases, is restricted to the GP and SN, suggesting selective involvement of these structures.
Asunto(s)
Globo Pálido/diagnóstico por imagen , Neurodegeneración Asociada a Pantotenato Quinasa/diagnóstico por imagen , Sustancia Negra/diagnóstico por imagen , Ultrasonografía Doppler Transcraneal/métodos , Adolescente , Adulto , Femenino , Globo Pálido/patología , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Mutación/genética , Neurodegeneración Asociada a Pantotenato Quinasa/genética , Neurodegeneración Asociada a Pantotenato Quinasa/patología , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Sustancia Negra/patologíaRESUMEN
INTRODUCTION: The word artifact stands for any visible result of imaging procedures which is caused by the procedure itself and not the entity being analyzed. Recognition of artifacts in everyday work is of great significance for final diagnosis, since their wrong interpretation not only compromises the value of ultrasound finding, but may also lead to a wrong therapeutic approach. ULTRASOUND ARTIFACTS: Artifacts appear as the result of physical properties of an ultrasound beam, technical aspects of ultrasound apparatus and immobility in creation of ultrasound image. Artifacts in the form of acoustic shadows, acoustic enhancements and reverberation most commonly appear and lead to changed appearance of certain structures. That is why great experience and knowledge of radiologists-ultrasonographists is necessary, since diagnostic accuracy of the method itself is under their immediate control. Incorrect interpretation of artifacts and failure to recognize them reduces the value of ultrasound imaging which has, during the past 25 years, confirmed its exceptional diagnostic value.