Updated in Diagnosis of Acute Ischemic Stroke CTMRI and advances

Updated in Diagnosis of Acute Ischemic Stroke: CT/MRI and advances Nguyen Quang Anh, MD VIETNAM NATIONAL CONGRESS OF CARDIOLOGY 15 th Meeting, Ninh Binh... Introduction • Ischemic: 80

Updated in Diagnosis of Acute Ischemic Stroke:

CT/MRI and advances

Nguyen Quang Anh, MD

VIETNAM NATIONAL CONGRESS OF CARDIOLOGY

15 th Meeting, Ninh Binh

Introduction

• Ischemic: 80% of stroke

• 3rd leading cause of dead in United States

• 2025: prediction of 1.2 millions patients/year

• In Viet Nam, stroke is top cause of Death (account for 18% - 2008)

• Cardiovascular disease, diabetes…

Diagnostic Tools

• Multi-choices in diagnosis

• CT Scanner -> MRI (3 steps)

• Perfusion -> Multiphase

CT Scanner protocol

• CT non-contrast: rule out hemorrhage + identify ischemic stroke area

• CT Angiography: arterial occlusion

• PW: if possible (double dose of contrast)

MRI protocol

• T2*: rule out hemorrhage + identify cerebral

microbleeding

• DWI: core of infarction

• FLAIR: parenchymal lesion/ absence of “flow voids” in the occluded artery

• TOF 3D: arterial occlusion site

• PW: if possible

Non-contrast

• “Emergency imaging of the brain is recommended before any specific treatment for AIS Non-enhanced CT will

provide the necessary information for initial treatment of

IV r-tPA (Class I; level of Evidence A - same as 2013)*”

*AHA/ASA-stroke guide line 2015

CT Non-contrast

• Rule out the hemorrhage

• Identify ischemic lesion

• Tips:

• Change the window level

–C: 8 –W: 32

- Rule out hemorrhage

- Identify cerebral microbleeding

-> risk factor of bleeding after

treatment

T2*

Kidwell Stroke 2002; Nighoghossian Stroke 2002; Derex Cerebrovasc Dis 2004

Identify occlusion site

T2*

Acute stage < 6h

Acute stage (6-24h)

Early sub-acute stage: 48hrs - 3 weeks

Late sub-acute stage

Chronic stage

ASPECTS

• ≥ 6: favorable clinical outcome*

*Stroke, 2008 39(8): p 2388-2391

• ≥ 6: favorable clinical outcome*

L

ASPECTS

• ≥ 8: favorable clinical outcome*

Pc-ASPECTS

*Stroke, 2008 39(9): p 2485-90

• DWI = irreversible lesion = core of infarction

• Bigger core, worse outcome

• In the MCA occlusion, core volume in DWI > 100cm3

-> no indication of treatment (>1/3 territory of MCA)

• >70cm 3 : poor prognosis even rapid recanalization *

• <70cm 3 : good outcome (64%) after quick recanalization

Volume V<30cm 3 V>30cm 3 N

Correlation between Volume of infarction

and clinical recovery in our study

• V<30cm3: good prognosis

p < 0.05

(*) Nguyen Duy Trinh, Pham Minh Thong 2014

Angiography

CT Angiography (MSCT)

• “A non-invasive intracranial vascular study is strongly

recommended If not possible at the time of initial

imaging, r-tPA should done first then try vascular imaging

as quickly as possible (Class I, level A - New)”

*AHA/ASA-stroke guide line 2015

CT Angiography

MIP (Single phase) VRT

MRI TOF 3D

Perfusion

CT Perfusion

• “The benefit of CT perfusion, DWI/perfusion-weighted

imaging for selecting patients (ASPECTS<6…) for

endovascular therapy are unknown ( Class IIb; level C - New ) Further randomized, controlled trials should be done * ”

*AHA/ASA-stroke guide line 2015

Lesions = Core (irreversible ) + penumbra (reversible)

CT Perfusion

MTT: mean transit time, CBF: Cerebral Blood Flow

TTP: Time to peak, CBV: Cerebral blood volume

MTT

CBV CBF

TTP

DWI PERFUSION - MECHANISM

MRI Perfusion

Match PW/DW -> no

penumbra -> no indication

of treatment

Mismatch PW/DW

-> good indication for treatment

CT Scanner

– Low sensitivity; PW only for anterior

circulation (64 slices)

– 2 times of contrast (Angio & PW)

– Can not discover micro bleeding

• Only 1 time of contrast (PW)

• Identify micro bleeding

• A little slower but acceptable

• Patient need to be very stable

• Mostly in big hospital

• No radiation

Comparison

New update

• CT Angiography Multiphase is a good choice

• Simple procedure

• Just published in 2015

• Data from PRoveIT (Menon et al)

• N = 147, comparison between CT Multiphase, single phase and CT Perfusion

• Just only the brain

• Time for moving table+scan

Evaluation

Menon et al., (2015) Neuroradiology, 000 (0).

Evaluation scale

0 Không quan sát thất bất kỳ nhánh mạch máu nào đi vào vùng nhồi máu tại

bất kỳ phase nào

1 Có một vài nhánh mạch máu nhỏ đi vào vùng nhồi máu tại bất kỳ phase nào

2 Chậm 2 phase hiện hình mạch máu vùng ngoại vi VÀ giảm đậm độ-tốc độ

ngấm thuốc, HOẶC chậm 1 phase nhưng có vùng không có mạch máu

3 Chậm 2 phase hiện hình mạch máu vùng ngoại vi, HOẶC chậm 1 phase

nhưng số lượng mạch máu trong vùng nhồi máu giảm

4 Chậm 1 phase hiện hình mạch máu vùng ngoại vi, nhưng đậm độ và tốc độ

ngấm thuốc thì tương tự

5 Không có chậm phase, quan sát thấy ngay các nhánh mạch máu bàng hệ đi

vào bình thường hoặc nhiều hơn trong vùng nhồi máu

• 0-3: nghèo bàng hệ (poor)̣, 4: vừa (moderate), 5: tốt (good)

• Left M1 occlusion (19h00’ ASPECTS ~ 8 point)

Case 2a

• Male, 75 years old, history of cardiac coronary disease

• Stroke during hospitalizing time (17h30’) due to chest pain

• Right hemiplegia, unconscious, G~13pt, NIHSS = 19

PHASE 1 PHASE 2 PHASE 3

• Multiphase score ~ 4 point (good collateral)

Multiphase

DSA (19h50 ’ – 20h10 ’ )

• Solitaire 6/20: 1 times

• TICI 3

Follow up

• G ~ 15pt

• NIHSS ~ 6pt

• mRS ~ 2 after 2 days

Case 2b

• Female, 57 years old; Atrial fibrillation, still using anticoagulant

• Administered to BM hospital in 2 nd hours (13h15’->14h30’)

• Left hemiplegia, NIHSS = 18

• Right ICA occlusion (14h45’ ASPECTS ~ 6 point)

PHASE 1 PHASE 2 PHASE 3

Multiphase

• Multiphase score ~ 2 point (poor collateral)

DSA (15h15 ’ – 15h57 ’ )

• Solitaire 6/30: 4 times

• TICI 3

MRI follow up

• G 15pt

• NIHSS ~ 9pt

• mRS ~ 4 after 2 wks

Conclusion

• CT Scanner noncontrast and MSCT is very important and always/strongly recommended in AIS (in new guideline 2015) before any treatment – easy and accessible in all hospital

• MRI only in big hospital, very useful especially in unknown time stroke patients/ same function as CT

• DWI/PW: good information but need more trial to prove its evidence and cut-off volume in prognosis

• CT Multiphase: new choice and simple, also need more trials and time

THANK YOU FOR YOUR ATTENTION