CASE 12711 Published on 22.05.2015

CT and MR imaging in acute stroke to evaluate intra-arterial therapy: a case report

Section

Interventional radiology

Case Type

Clinical Cases

Authors

Sebastiano Fabiano, Francesca Di Giuliano, Eva Salvatori, Jacopo Scaggiante, Giovanni Simonetti

Fondazione Tor Vergata,
Dipartimento di Diagnostica per Immagini
e Radiologia Interventistica;
Viale Oxford 81
00100 Roma, Italy;
Email:francescadigiuliano@msn.com
Patient

52 years, male

Categories
Area of Interest Head and neck, Interventional vascular, Vascular ; Imaging Technique CT, CT-Angiography, CT-Quantitative, MR, Catheter arteriography, MR-Angiography
Clinical History
A 52-years-old man, while in complete well-being, suddenly fell down to the ground unconscious and was transported to the emergency room within 30 minutes. Physical examination was performed noting drowsiness, dysarthria, left facial droop, arm and leg paralysis and a gaze toward the right. These symptoms were suspicious for stroke.
Imaging Findings
The CT documented an area of decreased attenuation of the right lenticular nuclei, a loss of grey-white matter differentiation in the right hemisphere and a “hyperdense MCA sign”, suggestive for intravascular thrombi. In order to evaluate the quantitation of ischaemic involvement, the patient underwent also a CT angiography (CTA) with perfusion (CTP) and a MR with diffusion (DWI). The CTA reported the tandem occlusion of the right ICA and MCA. CTP perfusion maps of mean transit time (MTT), cerebral blood volume (CBV) and cerebral blood flow (CBF) showed an area with decreased blood volume that represented ischaemic core and an area with normal blood volume but decreased blood flow and increased mean transit time that represented penumbra. The MR-DWI showed an area with decreased diffusion and confirmed the extension of the ischaemic core.
Discussion
Stroke is an acute central nervous system injury with an abrupt onset. 80% of strokes are caused by acute ischaemia. In the past imaging was used to exclude haemorrhage or other mimics of stroke, now diagnostic imaging is fundamental to identify patients who would differentially benefit from different treatment such as intravenous t-PA or endovascular therapy.
Unenhanced CT is the first examination that should be performed when suspecting ischemia because is widely available [1]. Unenhanced CT in a large vessel occlusion could show hyperdense vessel sign, insular ribbon sign and obscuration of the lentiform nucleus. Angiography CT is a widely available technique for assessment of both intracranial and extracranial circulation and shows thrombi in intracranial vessels [2].
CT perfusion is a new techniques could differentiate between an ischaemic penumbra (region of constrained blood flow in which energy metabolism is preserved) and infarcted tissue.
The presence of an ischaemic penumbra is an indication that thrombolytic therapy may be beneficial.
In “Guidelines and recommendations for perfusion imaging in cerebral ischaemia” the role of perfusion imaging was confirmed [3] in diagnosis and therapy for acute stroke because it may help to determine the relative benefits and risks of a given therapy.
Recanalization of arteries serving tissues that are severely ischaemic or infarcted may increase the risk of oedema and haemorrhage and unfavourable outcome [4].
In our case the diagnosis of right ischaemic stroke with tandem lesions in the right ICA and MCA was made in our department with a 64SL MDCT and a 3.0 T MR device.
In order to restore blood flow, the patient was transported immediately to the angiographic suite and underwent a mechanical thrombectomy with thrombus aspiration. A femoral artery access was obtained with a micropuncture set to minimize potential groin bleeding after the procedure and a 6F guiding sheath was inserted; the left common carotid artery was catheterized in order to evaluate collaterals flow, then the right common carotid artery was catheterized to diagnose the site of proximal occlusion. At this time, a drug-eluting stent was positioned to maintain patency of the right ICA and the simultaneous use of a stent retriever (Revive) and a thrombus aspiration system (Penumbra) permitted to restore blood flow. Finally, the patient was managed in the intensive care unit with frequent neurological evaluations and tight control of blood pressure. A MR after 2 days confirmed the ischaemic lesion previously described and the rescue of penumbra.
Differential Diagnosis List
Acute ischaemia in the region of the right middle cerebral artery
Haemorrhage
Brain neoplasm
Metastaes
Final Diagnosis
Acute ischaemia in the region of the right middle cerebral artery
Case information
URL: https://eurorad.org/case/12711
DOI: 10.1594/EURORAD/CASE.12711
ISSN: 1563-4086