Transcript Non Hyperperfused tumor

Diagnostic
performance of ASL in
the characterization of
brain lesions

Mathieu Schertz 1,2, Michael Majer 1, Samia Belkacem 2, Mehdi
Mejdoubi1 , Didier Dormont2, Alessandro Arrigo 1, Nadya
Pyatigorskaya 2
1

1. Department of Radiology, CHU Martinique, Fort de France, France (FWI)
2. Department of Radiology, Hôpital Pitié Salpetrière, 75013, Paris France
INTRODUCTION

ASL (arterial spin labeling) is a non-invasive way to measure cerebral
blood flow
Post taging
acquisition
Arterial Blood
Tagging

Post
label
delay
Difference between tagged and non tagged images (Relative Cerebral
Blood Flow (rCBF) is correlated to Histopathologic Vascular Density
Noguchi et al. AJNR 2008
2
OBJECTIVE

To evaluate the diagnostic accuracy of ASL in the characterization of the
neoangiogenesis and vascularity of different brain lesions

To evaluate the added value as compared to the conventionnal sequences
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Patients and methods

Patient Population :

Retrospective study (2013-2015)

Approval of the local ethics committee

Bicentric

University Hospital of Martinique (French West Indies)

University Hospital of Pitié Salpetrière (Paris)

Consecutives patients admitted for characterization of undetermined
brain lesions

Diagnostic confirmation : pathologic findings, evolution

Lesions were divided in “hyperperfused” and “non-hyperperfused” on the
basis of the histopathology knowledge
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Patients and methods

Imaging techniques :

Pseudocontinuous ASL

Repetition time : 4766 ms (1,5T) / 4733ms (3T)

Echo time : 10,7 ms (1,5T) / 9,8ms (3T)

Postlabeling delay from 1525 to 2025 ms

Total acquisition time of 4 minutes

Exclusion criteria :

motion or artifacts generated by dental hardware (n=8)
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Patients and methods

Review of MR Imaging Examinations :

4 Independent radiologist

2 blinded lecture per radiologist

First : MRI usual sequences

Then : MRI usual sequences + ASL sequence (Row data)

Confidence level in the diagnostic graded from 1 to 5 for each lecture

Subjective gradation of perfusion :

Hyperperfused tumor (visual increase of Cerebral Blod Flow (CBF)

Non Hyperperfused tumor ( iso or hypoperfused tumor)
 Objective gradation of perfusion :

Ratio rCBFtumor / rCBFcontrolateral
(ROI >50mm², Average rCBF per ROI)
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RESULTS

102 Patients included :

30 from University Hospital of Martinique (French West Indies)

72 from University Hospital of Pitié Salpetrière (Paris)

Mean age = 58 years old

59% of men

1,5T MRI examination = 39

3 T MRI examination = 63
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RESULTS : “Non hyperperfused” group
N
Rated as
hyperperfused
Rated as non
hyperperfused
Racio rCBF
Low grade Glioma
5
0
5
1,0
Lymphoma
6
1
5
1,2
Radionecrosis
7
0
7
0,9
Schwannoma
4
0
4
1,0
Abscess
4
0
4
0,8
Medulloblastoma
2 neurobehcet(2),
1
1
*Other
(9) = subependymoma(2),
Pseudo tumoral
MS (1), 1,3
histiocytosis
(1) , IRIS (1), epidermoid cyst (1), ganglioglioma (1)
pituitary adenoma
Other*
2
9
0
0
2
9
0,7
0,6
TOTAL
39
2
37
0,9
*Other (9) = subependymoma(2), neurobehcet(2), Pseudo tumoral MS (1),
histiocytosis (1) , IRIS (1), epidermoid cyst (1), ganglioglioma (1)
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RESULTS : “Hyperperfused” group

86 Patients inclus

29 Martinique

57 Glioblastoma
Paris
N
Rated as
hyperperfused
Rated as non
hyperperfused
Racio rCBF
23
21
2
2,6
Metastasis
9
8
1
2,4
Meningioma
18
17
1
3,6
Hemangioblastoma
4
4
0
12,3
Tumoral progression
7
6
1
1,9
Other*
2
2
0
1,8
TOTAL
63
58
5
3,4
*Other (2) = Craniopharyngioma (1), anaplasique glioma (1)
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RESULTS

Diagnostic accuracy for visual rating:

Sensibility : 92%

Specificity : 94%

Positive predictive value : 96%

Negative predictive value : 88%

Youden = 0,86

Interobservator agreement : Cohen's kappa coefficient = 0.91
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RESULTS

Diagnostic accuracy for quantitative rating

Average Racio rCBF for hyperperfused tumors: 3.4

Average Racio rCBF for non hyperperfused tumors : 0.89
Treshold : 1.3 :


Se = 92%

Sp = 85%

Youden = 0,77
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RESULTS : Added Value of the technic



Diagnosis was changed (for the correct one) after ASL lecture in 22 cases
(22%)

Radionecrosis vs tumoral progression (10/13)

GBM vs lymphoma/medulloblastoma
Sensibility and specificity in group classifying improved significantly after
ASL reading :

Sensibility : 76% -> 92%

Specificity : 66% -> 94%
Improvement of confidence level after ASL lecture in 52 cases (51%)

Average improvement 1 points / 5

Higher improvement for non experimented physicians
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EXAMPLE
T1 post gadolinium
rCBF map (ASL))
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EXAMPLE
T1 post gadolinium
rCBF map (ASL))
Hypoperfused Multiple Brain Abscess
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EXAMPLE
T1 post gadolinium
Axial FLAIR
ADC Map
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EXAMPLE
T1 post gadolinium
ADC Map
rCBF map (ASL))
Hyperperfused Glioblastoma
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EXAMPLE
rCBF map (ASL))
ADC Map
T1 post gadolinium
Hypoperfused Lymphoma in immunocompromised
patient (no restricted diffusion because of steroid
treatment before MRI)
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Low grade vs High grade glioma


Visual analysis:

Sensibility : 91.3%

Specificity : 100%

Positive predictive value : 100%

Negative predictive value : 71.4%
rCBF quantification:

Average Racio rCBF for High gliomas: 2.58

Average Racio rCBF for Low grade gliomas : 0.97

Treshold : 1.23 :

Se = 92%

Sp = 80%
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EXAMPLE
Non contrast CT
T2*
T1 post gadolinium
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EXAMPLE
rCBF map (ASL))
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EXAMPLE
rCBF map (ASL))
Hemorragic Glioblastoma
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EXAMPLE

32 years old pregnant women
T1 post gadolinium
Axial FLAIR
Diffusion B 1000
ADC Map
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EXAMPLE

32 years old pregnant women
rCBF map (ASL)
T1 post gadolinium
Axial FLAIR
Diffusion B 1000
ADC Map
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EXAMPLE

32 years old pregnant women
rCBF map (ASL)
T1 post gadolinium
Axial FLAIR
Diffusion B 1000
ADC Map
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Sub tentorial Glioblastoma
Glioblastoma vs unique metastasis

Peripheral tumor infiltration (Glioblastoma):


Peripheral reactional oedema (Metastasis):


Hyperperfused (13/23)
Non hyperperfused (8/9)
Visual assessment diagnostic accuracy (perfusion of the periferic
hypersignal):

Sensibility : 56%

Specificity : 88%

Positive predictive value : 92%

Negative predictive value : 44%

Interobservator agreement : Cohen's kappa coefficient = 0.72
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EXAMPLE
T1 post gadolinium
Axial FLAIR
rCBF map (ASL)
65 years old woman with history of brest cancer
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EXAMPLE
2 Slices up
T1 post gadolinium
Axial FLAIR
rCBF map (ASL)
65 years old woman with history of brest cancer
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EXAMPLE
2 Slices up
T1 post gadolinium
Axial FLAIR
rCBF map (ASL))
Hyper pefused tumor
+ Hyperperfused zone in the periferic T2 hypersignal
=Glioblastoma
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Tumoral progression vs radionecrosis


Visual assesment:

Sensibility : 86%

Specificity : 100%

Positive predictive value : 100%

Negative predictive value : 88%
rCBF quantification:

Average Racio rCBF for tumor progression : 2.07

Average Racio rCBF for Low grade radionecrosis : 0.87

Treshold : 1.2 :

Se = 86%

Sp = 71%
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RCBv MAP using T2*
injected perfusion
EXAMPLE
T1 post gadolinium

rCBF map (ASL))
77 year old man with history of glioblastoma radioterapy
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RCBv MAP using T2*
injected perfusion
EXAMPLE
T1 post gadolinium
rCBF map (ASL))
Radionecrosis
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Qualitative vs Quantitative evaluation
qualitative
visual analysis
Comparative Analysis
TRESHOLD
TOTAL hypoperfused vs hyperperfused
lesions
1,3
Se
0,92
0,92
Sp
0,94
0,85
Youden
0,86
0,77
TRESHOLD
Low grade Vs High grade glioma
1,23
Se
0,913
0,92
Sp
1
0,8
Youden
0,913
0,72
TRESHOLD
Tumoral progression vs radionecrosis
quantitative
rCBF analysis
1,2
Se
0,86
0,86
Sp
1
0,71
Youden
0,86
0,57
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DISCUSSION

Correct lesion classifying by visual rating and quantification

HYPERPERFUSED LESIONS


Glioblastoma (+ peripheral tumor infiltration)

Metastasis

Hemangioblastoma

Meningioma
NON HYPERPERFUSED LESIONS

Low grade gliomas

Lymphoma

Abscess

Medulloblastoma (+/- depending on the histological subtype)

Pseudo tumoral lesions (Multiple Sclerosis, Neuro Behcet…)
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DISCUSSION

Good visual assesment diagnostic accuracy

Se : 92% Sp: 94%

Added value : Diagnosis was rectificated after ASL lecture (22%)

Increased diagnostic confidence (1 point/5)

Good subgroup diagnostic accuracy :


glioblastoma vs unique metastasis

Low grade Vs High glioma (Treshold racio rCBF = 1,2)

Tumoral progression vs radionecrosis (Treshold racio rCBF = 1,2)
Visual evalation of perfusion have better acuracy than quantitative
evaluation
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CONCLUSION

Contrast enhancement with ASL hyperperfusion = Neo angiogenesis and
vascularity

Contrast enhancement without ASL hyperperfusion = Blood brain barrier
rupture

Future :

Assess difference with DSC post contrast perfusion (Magnetic suceptibility
Artefact : blood ; brain gadolinium deposit)

Assess difference 1,5/3T

Post Label Delay (PLD) Modulation
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