mri -current and future applications-...figure 5: summary receiver operating characteristics (sroc)...
TRANSCRIPT
MRI-current and future
applications-
Masako KataokaDept. of Diagnostic Imaging and Nuclear MedicineKyoto University Graduate School of Medicine
Abbreviated version: please note that some of the images/slides used in the actual talk were omitted.
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Morphology Kinetics(vascularity)
UltrafastAbbreviated
Dedicated breast PET(+metabolic info.)
DWI(Cellularity, morphology,
vascularity,structure)
Outline
1. Ultrafast(UF) -DCE MRI2. DWI –recent advancement3. Dedicated breast PET
What is UF-DCE MRI?
Scanning (at very early phase) with high temporal resolution (seconds)& high spatial resolution
Kinetic curve at very early phase
“FAST” scanning tech is needed
Ultrafast (UF)-DCE MRI
injection start
UF-DCEHigh Resolution
CEC-DCE(delay)
C-DCE(initial)
C-DCE(pre)
SI
Sec-60 0 60 120 180 240 300 360
pre+19 frames(every 3.7sec/frame)
-15-75
Parallel imaging 01
View-sharing 02
Compressed sensing 03
Ultrafast (UF)- DCE MRISteeper curve – more likely to be malignant
Mann R et al. Investigative Radiology 2014
Information obtained on UF-DCE MRI is comparable to that obtained by Conventional (C)-DCE MRI. Abe H et al. AJR 2016
Diagnostic performance of UF-DCE =C- DCE
0 2 4 (min.)
Conventional (C) -DCE MRIBI-RADS curve analysis
Ultrafast DCE MRIlook at the early upslope
Artery
Vein
AVI
Artery
Vein
Interval
MS
Slope
TTE
Time
empiric mathematical model (EMM)Mori N, Pineda FD et al. AJR 2018.
Examples of kinetic parameter in UF-DCE MRI
Curve fitting
Maximum Slope (MS)of the contrast enhancement versus time curve
• A parameter of the inflow of contrast in lesions.• How fast/strong the lesions enhance.
• Malignant lesions show steep upslope (large MS). • Equivalent or better diagnostic performance
compared to washout info. from C-DCE MRI
→Time (sec)
type1
type 2
type 3
50° 30°
Rel
ativ
een
hanc
emen
t(%
)
10 15 20 25 30 35 40 45 50 55 60 65 70Time (sec)
Relative enhancement (%)
type 1 → malignanttype 3 → benign
the slope of the tangent (%/s) along the steepest part of the curve
Mann RM et al. Invest Radiol, 2014.Goto M et al. European Radiology 2018.Ohashi A et al. European Journal of Radiology 2019 ( in press)Honda M et al. JMRI 2019 (in press)
Time to enhancement (TTE)
• Malignant lesions start to enhance earlier (shorter TTE) than benign lesions.
0
50
100
150
200
250
10 20 30 40 50 60 70
Aorta LesionTime (sec)
Relative enhancement (%)
Lesion
Aorta
“The time point where the lesion starts to enhance” minus “the time point where the aorta starts to enhance”
• A parameter of the inflow of contrast in lesions.• How early the lesions start to enhance.
• Time of arrival (TOA) similar but more precisely defined
• Bolus arrival time (BAT) : start of injection-bolus arrival at a lesion
Mus RD et al. Eur J Radiol, 2017.Pineda et al. Academic Radiology 2016.Goto M et al. European Radiology 2018.Honda M et al. JMRI 2019 (in press)
7/20frames
AVI = 8 – 7 = 1 frame
Artery
Natsuko Onishi , et al. JMRI. 2017
The time interval between arterial and venous visualization (AVI)
• A parameter to evaluate breast vascularity when arteries and veins are visualized
• Thanks to the compressed sensing technique, detailed peri-tumoral vasculature can be evaluated.
• A-V interval is shorter for malignant lesions than for benign lesions.
“The time point where the breast vein starts to enhance” minus
“the time point where the breast artery starts to enhance”
8/20frames
Vein
Maya Honda, et al. JSMRM 2017
AVI for breasts with cancers were significantly shorter than those for breasts with benign lesions (*P=0.043) and with no lesions (**P=0.007).
Arterial Venous Interval -shorter in cancers
*
Natsuko Onishi. et al. JMRI 45, p617, 2017
Video slide on You Tube “JMRI ISMRM” channel “ultrafast”
usual ductal hyperplasia(benign) Small MS (14.7%/sec)Large TTE(14.5 sec)AVI (3frames~11sec)-s/o benign
Although C-DCE kinetic curve showed washout
Honda M et al. JMRI (Epub 2019)
Benefit & Pitfalls
Benefit
UF-DCEHigh Resolution
CEC-DCE(delay)
C-DCE(initial)
C-DCE(pre)
SI
Sec-60 0 60 120 180 240 300 360-15-75
1.Shorter image acquisitionShorter reading time
(similar to “abbreviated MRI)
2.Easier to identify lesions in case of marked BPE3.Tumor-related artery & vein separation4.Detailed tumor-related vasculature can be evaluated
1. Number of iterations should be optimised
No. of Iteration 1→ 15→ 50
Sagawa H. et al. Magnetic Resonance in Medical science 2018 (Epub)
Invasive carcinoma
Optimal scan setting is required!
2. Compressed sensing: Reconstruction not speedy!3. The same lesion may look different in shape
Pitfalls
Honda M et al. IC-MRI 2019 , Kataoka M et al. ISMRM 2019
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Ultrafast DCE MRI- summary
Shorter scanning timeEarly phase kinetic curve analysis (seconds)New kinetic parameter (MS, TTE, AVI etc..)Useful in Marked BPEVisualize tumor-related vasculature
Outline
1. Ultrafast(UF) -DCE MRI2. DWI –recent advancement3. Dedicated breast PET
DWI-recent advancement“EUSOBI” are actively working on standardizing DWIIncrease in publications related to DWI & Breast
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Figure 5: Summary receiver operating characteristics (SROC) curves by using the bivariate model with 95% confidence regions. Thepooled area under the curve was 0.92 for the apparent diffusion coefficient (ADC), 0.90 for tissue diffusivity (D) and 0.94 for the prime diffusion coefficient (λ1).
Baxter GC et al. Radiology 2019 June
AUC 0.92 AUC 0.9 AUC 0.94
DWI-recent advancement
1. High resolution DWI
2. Non-ADC approach
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Diffusion Weighted Imaging(DWI)Random Brownian motion of water molecules Apparent diffusion coefficient (ADC) : quantified measure of diffusion
DWI
ADC map
Free water no restriction
Cancerrestriction ++
Tissuerestriction +
DWI LOW HIGH
LOWADC HIGH
DWI Signal intensity (SI) and ADC value-Monoexponential model-
b value
ln (SI)
0 500 1000
S(h) = S(0) ・ exp (-bD)ln SI = -bD + lnS0
ADC ~ slope
low ADC (cancer)
high ADC (cyst, FA etc..)
Problem of conventional DWI• Low spatial resolution• Susceptibility artifact-causing distortion• Poor fat suppression
Camp J. BJR 2019
High-resolution DWI for morphological assessment
-various strategies-Reduced FOV DWI
Bogner W et al. (2015), Radiology
Bickelhaupt S et al. (2015), Radiology
Barentsz M et al. (2015), JMRI 42, p1656
DWIBS (DWI + STIR)
Readout-segmented EPI at 7T
Readout-segmented EPI Kim, YJ et al. (2014), KJR 2014 CE vs DWI
Readout segmented EPI(rs-EPI: RESOLVE)
• K-space is divided into segments• Shorter acquisition time per shot• Less distortion (susceptibility artifact ↓)
• 2D navigator echoes for reduced sensitivity to motionDrawback: Longer scanning timePorter DA et al. MRM (2009)Bogner W et al. Radiology (2012)Wisner DJ et al. JMRI (2014)
HR-DCE MRI vs HR-DWI(HR) DCE MRI HR-DWI with Rs EPI
MR Sequense 3D VIBE Three direction traceSequence parameterFlip angle 15 degree b values (sec/mm2)
0, 850 TR/TE (sec) 4.01/1.63 10500/52
In-plane Resolution 0.7x0.6 1.1x1.1Thickness (mm) 0.8 1.5No. of Segments 7
NEX 1 1 and 2 (b=850 sec/mm2)Acquisition time 2min 26 sec 5min 15 sec
HR-DWI using rs-EPIFor known breast cancer-• Agree with DCE-MRI and pathology for mass lesions,
yet sometimes challenging for non-mass lesions• Non-contrast protocol with HR-DWI may work for
those with “suspicious” lesion. Currently limited to unilateral Screening ?
Excellent Excellent Underestimation
DW-MRI –non ADC approach
ADCo KfIVIMCE
IDC
PASH(benign)
Iima, Yano, Kataoka et al. Invest Radiol 2015.
Non-Gaussian parametric map
(b value)
80 500 1000 1500 2000 2500 3000 3500
SI
Iima, Kataoka et al. Radiology 2018
Using all three parameters helps to improve more accurate diagnosis without using contrast agent
IVIM
ADC
Kurtosis
DWI contains various info (multi b value data)- various approach (kurtosis, stretched exponential…)Potential for new biomarkers in oncology
Bedair R. et al. Eur Radiol (2017)
ROCs for the response prediction of the pretreatment diffusion coefficients. DDC (stretched exponential) performed best.Kurtosis (red) and
stretched-exponential (blue) models were best supported by the data
Suo. et al, JMRI (2017)
Beyond ADCIVIM& non Gaussian DWI
Jin YN. et al, JMRI (2019)
parameters derived from the biexponential & stretched-exponential DWI could provide additional information for differentiating between benign and malignant breast tumors
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DWI recent advancement-summary
Morphology can be evaluated Using high-resolution DWI
non-ADC parameters for new biomarkers
0.8-500 500 1500 2500 3500
Outline
1. Ultrafast(UF) -DCE MRI2. DWI –recent advancement3. Dedicated breast PET
Whole body (wb) PET/CT & dedicated breast (db) PET examination flow
185MBq FDG
wbPET
supine
dbPET
prone
60 min 5 min x both sides (2)
90-100 min
0 min
60 min waiting
What is the value of dbPET? Very small pixel size→ decrease partial volume effectMetabolic morphology associated with pathology(intratumoral heterogeneity)Treatment response (residual cancer after NAC)Screening?
Visualize metabolic & morphological info. with better sensitivity.
Female, 40th
Grade 3Triple negative subtypeKi-67 index: 60%
Sakaguchi R et al. Annals of Nuclear Medicine 2019 (E-pub)
What are the benefits for patients in using these “near future” approach?
1) Shorter, less invasive imaging
2) Comprehensive information for optimized /personalized management