Thursday 26 January 2012

Cavernoma (Cavernous Malformation)

Imaging findings of Cavernoma (Cavernous Malformation) are very typical on MR as in this case.
A focal lesion in right cingulate gyrus faintly hyper dense on Non contrast CT.
On MRI typical "popcorn ball" appearance with low signal intensity hemosiderin rim on T2w images.
T1 bright locules of Meth Hb on T1w images.
Low signal intensity blooming on T2*GRE due to paramagnetic effect of blood degradation product.
Faint enhancement on post contrast T1.
Mild perilesional edema on FLAIR.
No mass effect.

Cavernoma (Cavernous Malformation)

A benign vascular hamartoma, composed of closely packed immature blood vessels with intra lesional micro hemorrhages, without any neuronal tissue.
Best diagnostic clue is "Pop corn ball" like appearance with hemosiderin rim on T2w images.
Occur anywhere in brain. Rare in Spinal cord.
Vary in size from few mms to cms. Average size is between 1 to 5cm.
Usually single solitary, may be multiple, discrete lesions.
MRI is more sensitive and specific for detection of lesion.
Hyper dense on non contrast CT. Calcification seen in ~ 50% cases. No to faint enhancement on post contrast.
On MRI lobulated appearance due to multiple locules which show variable signals, depending up on the blood degradation products. T1 bright locules attributed to Meth Hb - a sub acute stage blood degradation product. Low signal intensity hemosiderin rim on T2 images. Low signal intensity blooming on  T2*GRE images. No to faint enhancement on post contrast T1 images.
No to mild peri lesional odema.
No mass effect.

Clinical presentation:
Seizures 50%
Neuro deficit 25%
Asymptomatic 20%, detected as an incidnetal finding.
No intervention is a rule. But need follow up imaging as it may show progression or regression in size. Rarely show massive bleed.
Can affect any age group.
No gender preponderance.
Familial association in Hispanic Americans - Multiple Cavernoma Syndrome, carries higher risk for bleed and re bleed.

AVM; may see 'pop corn ball'  appearance, but characterised by incomplete hemosiderin rim, flow voids on T2w images, areas of bleed instead of multiple locules of variable signals.

Similar Case :
Cavernoma with bleed

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