Điện quang can thiệp Việt Nam Hiện tại và tương lai

Advances in Diagnostic Imaging
of Acute Ischemic Stroke
CT or MRI
Prof. Pham Minh Thong M.D
Radiology Department
Bach Mai Hospital
Introduction
• Ischemic: 80% of stroke
• Third leading cause of dead in developed country
• Cardiovascular disease, diabetes,…
• 2025: prediction of 1.2 millions patients/year
• In Viet Nam, stroke is top cause of Death (account
for 18% - 2008)
“Time is brain”!
Diagnostic Tools
• Multi choices in diagnosis
• CT Scanner -> MRI
• Perfusion -> Multiphase
CT SCANNER
• “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
ASPECTS
• ≥ 6: favorable clinical outcome*
*Stroke, 2008. 39(8): p. 2388-2391
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
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*”
Lesions = Core
(irreversible )+ penumbra
(reversible)
*AHA/ASA-stroke guide line 2015
CT
Perfusion
MRI
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
T2*
- Rule out hemorrhage
- Identify cerebral microbleeding
-> risk factor of bleeding after
treatment
Kidwell Stroke 2002; Nighoghossian Stroke 2002; Derex Cerebrovasc Dis 2004
T2*
Identify occlusion site
MRI TOF 3D
ASPECTS
L
• ≥ 6: favorable clinical outcome*
Pc-ASPECTS
• ≥ 8: favorable clinical outcome*
*Stroke, 2008. 39(9): p. 2485-90
DWI PERFUSION - MECHANISM
MTT: mean transit time, CBF: Cerebral Blood Flow
TTP: Time to peak, CBV: Cerebral blood volume
CBF
CBV
TTP
MTT
MRI Perfusion
Match PW/DW -> no
penumbra -> no indication
of treatment
Mismatch PW/DW
-> good indication
for treatment
Case
Before
DWI
After
PWI
DWI
PWI
Comparison
CT Scanner
– Low sensitivity; PW only for anterior
circulation (64 slices)
MRI
• Very high Sv & Sp; PW for
whole brain
– 2 times of contrast (Angio & PW)
• Only 1 time of contrast (PW)
– Can not discover micro bleeding
• Identify micro bleeding
– Quick
• A little slower but acceptable
– Patient unstable -> fast scan
• Patient need to be very stable
– Widespread access
• Mostly in big hospital
– In case of contraindication with MRI
• No radiation
(Stent, pacemaker…)
Problem
• Some patients having less penumbra -> good
outcome
• In contrast, others who have good penumbra -> poor
outcome
-> Other factors affect the clinical recovery (collateral?)
-> Need a new method to evaluate salvageable brain
quickly, reliably and widely available
New techinque
• 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
Protocol
• Non contrast first then multiphase
• Phase 1:
• Evaluate the carotid and brain
circulation
• Double scan with contrast, then
subtraction algorithm
• Phase 2:
• Just only the brain
• Time for moving table+scan
• Total 8sec
• Phase 3
• Similar to phase 2
Menon et al., (2015). Neuroradiology, 000 (0).
Evaluation
Menon et al., (2015). Neuroradiology, 000 (0).
Evaluation scale
Điểm
Đánh giá (khi so sánh với bán cầu bên bệnh với bên lành)
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)
Recommendation
• CT Multiphase score ≥ 4 -> good collateral
• CT Multiphase score ≤ 3 -> poor collateral
• New method, useful in ESCAPE but need more trials to
proved its value
• Now applied in Bach Mai hospital protocol
ESCAPE
Design and results
• Methods
–
–
–
–
IV >< IV + MT in the first 4.5 hours
238/316 received rt-PA with 118 control >< 120 intervention
Treatment up to 12 hours with anterior circulation occlusion
NO large infarct core (ASPECTs < 6), NO poor collateral (<50%
filling pial artery of the MCA in the CT Multiphase)
• Results
– Stop early because of the efficacy
– Times from CT non contrast to groin puncture: 60mins/ to first
reperfusion: < 90 mins
– mRS 0-2: 29.3% >< 53% -> Thrombectomy is better
– Mortality: 19% >< 10.4%
– Symptomatic hemorrhage: 2.7% >< 3.6%
Bach Mai hospital protocol
• Noncontrast: 3.71 sec
• Phase 1:
• Scantime 6.2s
• Delay (contrast injection) 14 sec
• Scantime 6.2 sec
• Phase 2:
• Total time 5 + 3.71 sec
• Phase 3:
• Total time 5 + 3.71 sec
-> Only 17 sec more
Case 2a
•Male, 75 years old, history of cardiac coronary disease
•Stroke during hospitalizing time (17h30’) due to chest pain
•Left hemiplegia, unconscious, G~13pt, NIHSS = 19
• Right M1 occlusion (19h00’ ASPECTS ~ 8 point)
Multiphase
PHASE 1
PHASE 2
PHASE 3
• Multiphase score ~ 4 point (good collateral)
Perfusion
TTP
(Time to Peak)
• Mismatch > 35%
CBF
(Cerebral Blood Flow)
CBV
(Cerebral Blood Volume)
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 2nd hours (13h15’->14h30’)
•Left hemiplegia, NIHSS = 18
• Right ICA occlusion (14h45’ ASPECTS ~ 6 point)
Multiphase
PHASE 1
PHASE 2
PHASE 3
• 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 weeks
Protocol changes
• 1) Treatment:
– IV + MT in the first 4.5 hours
– After 4.5 hours, mechanical thrombectomy only
– No later than 6 hours
• 2) Good patients selection:
– NIHSS: from 6 (to 25)
– Age ≥ 18 (to 80)
– ASPECTS ≥ 6
• 3) Big arterial Occlusion (M1, ICA)/ Good collateral
Good combination
+
IV r-tpA
(For < 4.5hrs but don’t wait, do the
Mechanical Thrombectomy
right after transfusion)
Solitaire
(Priority)
Protocol in BM Hospital from 2012-15
Administered to the Emergency Department (10 mins)
First aid with clinical examination and test (10 mins)
CT/MRI (non contrast, angio, multiphase/ perfusion) (15mins)
Hemorrhage
Rule out
Ischemic with evidence of
big arteries occlusion
IR room (30-45 mins)
Conclusion
• CT Scanner noncontrast and MSCT is very important
and always/strongly recommended in AIS before any
treatment – easy and accessible in all hospital
• 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
• MRI: unknown time window, follow-up patient
THANK YOU FOR YOUR ATTENTION