Subacute Intracerebral Hemorrhage

Author

Assistant

Introduction

CT MRI

Aging the Hemorrhage on MRI

Hyperacute – minutes to hours

T1 – hematoma  (deoxyHb) dark => isointense

T2 – hematoma (deoxyHb) dark=> isointense

Acute – 0-2 days

deoxyhemoglobin is in intact RBCs with surrounding edema

T1- hematoma isointense, edema dark

T2 – hematoma  dark, edema bright

Subacute – 2-14 days

deoxyhemoglobin changes to methemoglobin from outer to inner

T1 – outer core bright

T2 – outer core bright due to shortened T1, longer T2

Chronic – 14 days

hemosiderin laden macrophages at periphery

T1 – inner core bright, rim dark

T2 – inner core bright, rim has low dark

Chronic – months later

hemosiderin laden macrophages at periphery

T1- mostly iso-/dark, rim is dark

T2- markedly dark rim – “blooms” with greater T2-weighting

Acute Embolic Infarct High Parietal Region

The axial images are from a patient with atrial fibrillation and neurological deficits.

Image a is a CT scan which shows a high density lesion i the vertex of the right pariettal lobe suggesting hemorhagic change.

Image b is a diffusion weighted MRI image at the level of the ventricles which shows a high intensity region in the parieto-occipital region suggesting acute infarction.

Image c is a axial T2 weighted image showing edema in the white matter of the right parietal lobe.

Image is aGRE image showing mixed heterogeneity with probable iron deposition suggesting subacute or chronic hemorhage.

Findings are consistent with old and new multicentric infarcts of the brain likely from the heart caused by atrial fibrillation

Courtesy Ashley Davidoff MD copyright 2010 71239c01

Subacute Hemorrhagic Infarct of the Parietal Lobe MRI

The series of MRI images from a 70 year old male who by history suffered a stroke 1 month ago and has new onset symptoms.  the series of images reveal complex changes of a subacute hemorrhagic infarct.  Image a is from a DWI sequence and it shows a heterogenous increase in signal some of which represents T2 shine throughand sopme of which is bright raising the question on an acute on subacute entity.  Image b is a sagittal T1 weighted image which shows areas of vague increase in density suggesting hemorrhage. Image c is a T2weighted sequence and shows some increase in water but the granular low intensity suggests hemosiderin deposit.  Image  d is FLAIR sequence showing increase brightness to the lesion in the left parietal lobe and image e is an axial FLAIR sequence The findings suggest  extensive infarct in the  left MCA territory which has mild mass effect on ventricles with petechial hemorrhage as seen on  T2 and FLAIR and hyperintense T2 shine through on diffusion weighted images The punctate areas in left parietal lobe with restricted area of diffusion raises the question of a recent small infarct less bright regions on DWI suggests a subacute hemorrhagic infarct.

Courtesy Ashley Davidoff MD copyright 2010 71000c03