Not infrequently,the nodule is difficult to detect and dynamic techniques may improve the detection rate Not infrequently the microadenoma may be hyperintense on the baseline TIWI,due to intratumoral bleed Pituitary Macroadenoma 15min A macroadenoma can remain confined within the sella turcica,or it may grow upward,downward,laterally or more commonly in all directions Plain films usually show an expanded sella with erosion and depression of the sellar floor toward the sphenoid sinus CT shows the same bony changes and the mass lesion.usually isointense,with marked enhancement MRI better shows involvement of the surrounding structures The tumor is usually isointense on Tl-weighted images and shows marked enhancement following gadolinium injection.Sometimes haemorrhagic and cystic components are present Acoustic neurinoma 15min A benign tumor deriving from schwann cells of the acoustic nerve It is the most frequent intracranial schwannoma Most commonly the neoplasm originates from the vestibular portion of the eighth cranial nerve It can be exclusively intracanalicular or may extend as a mass in the cerebellopontine angle Plain film radiographs can reveal widening of the internal auditory canal. which,however,is a late manifestation ofthe tumo On CT axial images intracanalicular schwannomas are usually missed Larger tumors both intra-and extracanalicular appear as oval or lobulated masses,they may present as a broad base against the petrous ridge at the⚫ Not infrequently, the nodule is difficult to detect and dynamic techniques may improve the detection rate ⚫ Not infrequently the microadenoma may be hyperintense on the baseline T1WI, due to intratumoral bleed Pituitary Macroadenoma ⚫ A macroadenoma can remain confined within the sella turcica, or it may grow upward, downward, laterally or more commonly in all directions ⚫ Plain films usually show an expanded sella with erosion and depression of the sellar floor toward the sphenoid sinus ⚫ CT shows the same bony changes and the mass lesion, usually isointense, with marked enhancement ⚫ MRI better shows involvement of the surrounding structures The tumor is usually isointense on T1 -weighted images and shows marked enhancement following gadolinium injection. Sometimes haemorrhagic and cystic components are present Acoustic neurinoma ⚫ A benign tumor deriving from schwann cells of the acoustic nerve ⚫ It is the most frequent intracranial schwannoma ⚫ Most commonly the neoplasm originates from the vestibular portion of the eighth cranial nerve ⚫ It can be exclusively intracanalicular or may extend as a mass in the cerebellopontine angle ⚫ Plain film radiographs can reveal widening of the internal auditory canal. which, however, is a late manifestation of the tumor ⚫ On CT axial images intracanalicular schwannomas are usually missed. Larger tumors both intra - and extracanalicular appear as oval or lobulated masses, they may present as a broad base against the petrous ridge at the 15min 15min