Basilar Artery Thrombosis-MRI
An adult male in sixth decade , hypertensive, presents with loss of consciousness after prolonged intercontinental flight (Canada to India) with no deep venous thrombosis of the lower extremity or cardiac disease. MRI shows acute ischemia pons with no bleed, with MRA showing lack of flow signal of midthird basilar , possibly due to atheromatous thrombosis with Brainstem DWI score of 6 suggesting moderate prognosis. Case submitted by Dr MGK Murthy, Mr Hari om and Mr Sahadev Gupta.
· Basilar is formed at pontomedullary junction
· Most important branches are AICA, PCAs with internal auditory meatal arteries at times directly arising from it
· Proximal and distal basilar blocks are due to embolism usually, while middle third is typically thrombotic
Posterior Circulation Acute Stroke Prognosis: Early CT Score(PCASP-ECTS) is calculated with the help of CTA source images :
(a) Total is taken as 10 points , with 0= ischemia in all and 10 =No Ishaemia
(b) 1 point each deducted for hypoattenuation in Left/ Right Thalamus,L/R Cerebellum and L/R PCA territory
(c) 2 points each deducted for hypoattenuation Midbrain/Pons
A 2009 Study has suggested pretreatment , baseline , Brain stem Diffusion weighted Imaging Score, as independent clinical predictor for prognosis
(a) Total is taken as 22 points , with 0= No ischemia in posterior circulation and 22= Whole Brainstem ischemia
(b) No of arterial territories with abnormal Diffusion signal at each brainstem level including anteromedial, anterolateral, lateral, and posterior regions is calculated.
(c) 0-8 is allotted for medulla and mid brain , with pons 0-6 only.
Basilar Artery Thrombosis-MRI Reviewed by Sumer Sethi on Monday, August 22, 2011 Rating: