27. Efecto de masa
• El edema agregado
puede producir
sintomatología no
inherente a la lesión
misma.
27
28. Hernias cerebrales
1. Hernia subfalcina
(sobre todo tumores
frontales),
2. Transtentorial de abajo
a arriba y la amígdalas
(tumores cerebelosos).
3. Hernia uncal (tumores
del lóbulo temporal),
4. De Amígdalas
28
49. Ventrículos
• Morfología Tamaño y
situación
• Variantes anatómicas
• Ensanchamiento ventricular
degenerativo, local o
generalizado.
• Desviación de la línea media.
• Densidad del liquido
• Niveles
• Lesiones intraventriculares
– Quistes
– Neoplasias
– Cisticercos etc.
49
71. Microadenoma
• <10
mm
diametro.
• Diferenciar de
quiste
de
Rathke.
• Sensibilidad de
RM: 70%.
Kucharczyk W, Hazewinkel M Sella turcica and parasellar region.
http://www.radiologyassistant.nl/en/485d7745cc720
72.
73. 9) Orbitas
• Contorno y
dimensiones
• Globos oculares
• Posición
• Simetría
• Intensidad de señal
• Lentes cristalinos
• Nervios ópticos
• Músculos y Grasa
• Estructuras vasculares
• Exoftalmos
• Masas intraorbitarias
• Reforzamiento
73
Pituitary Microadenoma By definition, pituitary microadenomas are less than 10 mm in diameter and are located in the pituitary gland. These images show a classic case: on T1 a lesion about 3-4 mm in diameter, slightly hypointense compared to normal pituitary tissue, located in the pituitary gland. On T2, the lesion is slightly hyperintense. The differential diagnosis: pituitary microadenoma or Rathke's cleft cyst (the two can be indistinguishable). The sensitivity of an unenhanced MRI scan for detecting pituitary microadenomas is about 70%. It is not always necessary to give intravenous contrast for detecting pituitary microadenomas as patients with a negative scan generally receive the same symptomatic treatment as patients with a microadenoma (usually these patients are women with symptoms of hyperprolactinemia). The purpose of the scan is to rule out any large lesions. In possible surgical candidates (for example patients with failed medical therapy or pituitary disease not amenable to medical therapy such as Cushing's disease) it is necessary to give contrast to localize the lesion as accurately as possible. On
Figure 5. Pituitary macroadenoma. Coronal unenhanced (a) and contrast-enhanced (b) T1-weighted images show a macroadenoma (arrowheads), which occupies the pituitary fossa and invadesthe left cavernous sinus (arrow).