Acute right MCA M1 occlusion

The noncontrast CT of the head demonstrated no intracranial hemorrhage, however an extensive hyperdense mediaMCA sign was was observed beginning in the M1 segment of the right MCA (see key image). An accompanying reduced density of the head of the right caudate nucleus and the right lentiform nucleus can be observed, when compared to the unaffected contralateral side (see rewindowed key images) corresponding to an ASPECTS score of 8. 

Incidentally, extensive calcification can be observed along the falx cerebri.

Evaluation with the e-ASPECTS software also confirmed the involvement of the right caudate and lentiform nucleusnuclei, and determined an ASPECTS score of 8. The examination was continued with the CT angiography. 

Multiphase CT perfusion angiography demonstrated the occlusion of the M1 segment of the right MCA with good filling of collaterals delayed by one phase, corresponding to an mCTA collateral score of 4. 

CT perfusion maps demonstrated reduced cerebral blood flow (CBF) and volume (CBV), and increased mean transit time (MTT) and Tmax in the ischemic region. The relative size of the infarct core and penumbra, and the potential recuperation ratio (PRR) was also calculated, demonstrating a relatively low value (40%), an indicator of unfavorable prognosis. However, based on the good ASPECTS score (8.) and mCTA collateral score (4.) the, the patient was nevertheless selected and admitted for urgent mechanical thrombectomy. which which was successfully performed.

The case of demonstratesdemonstrates a fairly typical sequence of imaging in acute MCA occlusion. The initial noncontrast CT shows subtle signs of ischemia; nevertheless, nevertheless the site of occlusion and the core ischemic regions can already be determined based on this. CT angiography confirms the occlusion and helps determiningto determine the collateral filling, while the true extent of ischemia is only revealed by CT perfusion and postprocessing.