CT of the brain tumors & abdomen
Medulloblastoma haemangioblastome notice the dense nodular enhancementPilocytic astrocytome Present in the childhood 5-15 Y Arise within the vermis & cerebral hemisphere CT finding appear as well circumscribed lesion hypo or hyper dense & growing mainly with expansion , usually large lesion solid or cystic or both of them , with , enhancing mural nodule 20 % show calcification of the nodule , may be associated with edema . Secondary metastasis Old age group above 50 Y , any lesion within the cerebellar hemisphere it is secondary metastasis unless proven otherwise F. from breast CA M. from bronchogenic CA . Appear as nodular single or multiple lesion hypo dense or hyper dense . Surrounded by per focal edema Enhanced as solid or ring pattern of enhancement .
Supra seller T. Cranio phyrengioma Tumor situated above the sella tursica arise from the remnant of the rathekes pouch , an embryonic structure from which the pituitary gland is partly formed . CT finding The t. might invade sella tursica , then go anterior , posterior or upward , sometime reach the third ventricle . Deformity of the supra sellar cistern The t. have solid & cystic component , post contrast solid part will get enhancement , flecks of calcification seen around the lesion as multiple rings . The lesion might obstruct the third ventricle &present with obstructive hydrocephalous .
Hydrocephalous 2 typesObstructive ( non – communicating ) Craniophyrengioma MedulloblastomaEpendymomaAquiduct stenosis , comments cause of obstruction being congenital in nature . Non –obstructive ( communicating ) No obstruction of the ventricular pathway , but the absorption of the csf at the level of arachnoids' granulation is occluded secondary to lodge by blood clot or inflammatory cell or infection post meningitis most commonly to occur post SAH .
Hydatid cyst
Normal CT of the abdomenCT abdomen Hydatid cyst Appear as large oval hypo dense area density of fluid with well defined margin , sometime at their periphery multiple flecks of calcification are seen at their periphery . Hydatid cyst with daughter cyst , appear as multiple hypo densities rounded area within the main loculi with multiple rim of calcification Secondary metastasis in the liver Multiple rounded hypo density areas of different density , shape & different size . Pattern of enhancement is either uniform , target or bulls eye pattern . Hepato megaly .
Hydatid cyst within the liver
Secondary metastasis within the liverPancreatitis Patient present with abdominal pain , vomiting with or without jaundice , increase amylase level CT finding Enlargement of the pancreas focal or generalized increase in size . Hypo density within the pancreas focal or generalized due to the edema . Peri pancreatic fluid collection & edema around the pancreas . The fluid around the pancreas if persist more than 6 w become encysted leading to the pancreatic pseudo cyst any area could be affected . Edema of the wall of the stomach .