Regarding vertebral anomalies

the posterior arch of the atlas is not fused in 5% of the normal population

intervertebral fusion is commonest in the lumbar region

cervical ribs are found in less than 2% of the normal population

non-fusion of the neural arch of L5 or S1 is seen in 5% of the normal population

a transitional L5 vertebra is found in 5% of the normal population

In Chiari malformations

type I is seen in up to 10% of the normal population

the medulla is kinked in 50% of type I

the cerebellar tonsils are most inferior in type II

myelomeningocoele is seen in 50% of type II

50% of symptomatic type I will have syringomyelia

In syringomyelia

the cavity has an ependymal lining

the spinal cord is not expanded in 20% of cases

cerebellar ectopia is seen in 50% of patients with syringomyelia

there are plain film abnormalities in 10% of cases

there is a change in the size of the cord between the supine and prone position in 15% of cases

Regarding spinal tumours

meningiomas are most common in women

enlarged intervertebral foramina are seen in 10% of neuromas

capillary haemangioblastomas are solitary in 30% of cases

50% of intramedullary tumours are associated with syringomyelic cysts

enlarged vessels are seen on myelography with 50% ependymomas

Gallstones

occur in 10-15% of the adult UK population

are five times commoner in women

cholesterol stones are associated with cirrhosis

are found in two-thirds of patients with pancreatitis

50% of pigmented stones are radio-opaque

Calcification in the liver

is seen in 2% of hepatocellular tumours in adults

is seen in 35% of hepatocellular tumours in children

is stippled in angiomata

is curvilinear in hydatid disease

is nodular and scattered in TB granulomata

Caroli's Syndrome

features congenital fibrosis of the intrahepatic bile ducts causing constriction

is associated with medullary sponge kidney

demonstrates X-linked inheritance

has an association with cholangiocarcinoma

is caused by a choledochal cyst

Gas

seen in the portal vein with necrotising enterocolitis is central

may be seen in the liver following tumour embolisation

in the biliary tree indicates a life-threatening condition

is seen in the portal vein after infarction of bowel

is seen in the portal vein with haemorrhagic pancreatitis

In the pancreas

microcystic cystadenomata are always benign

microcystic cystadenomata usually have fewer than 6 cysts

macrocystic cystadenomata usually have fewer than 6 cysts

amorphous calcification occurs in microcystic cystadenomata

cysts are a feature of Von Hippel Lindau disease

Regarding ectopic hormone production

pancreatic carcinoma may produce ADH

bronchogenic carcinoma may produce ADH

oat-cell carcinoma may produce ACTH

bronchogenic carcinoma may produce thyroxine

thymic tumours may produce ACTH