Download Imaging veins, oxygen extraction fraction, arteries - SWIM

Imaging veins, oxygen extraction fraction, arteries and vessel wall using susceptibility weighted imaging (SWI) and susceptibility mapping (SWIM)
SWI
E. Mark Haacke
Department of Radiology,
Wayne State University
Detroit, Michigan
SWIM
Conflicts of Interest
• Support from Siemens Medical Systems
• DoD grant on SWI and SWIM
• NIH grant on USPIO susceptibility
Qualitative SWI versus quantitative susceptibility mapping (QSM) or SWIM
0.5mm isotropic resolution, TE = 20ms, 3T
SWI
SWIM
Imaging veins and blood products using SWI and SWIM1‐3
MRA
SWI
SWI
MCI case
TBI case
SWI
a
SWIM
b
SWIM reversed
c
Imaging veins and blood products using SWI and SWIM:
Challenging the neurovascular system4
200mg caffeine pills (a, d)
or 1000mg diamox IV
injection (c, f).
SWI
Compared to the control
condition (b,e),
significant oxygen
saturation changes are
observed post-challenge
on veins throughout the
brain.
SWIM
Caffeine: flow change = − 27% ± 9% and ΔY = − 0.09 ± 0.02
Diamox: flow change = +40% ± 7% and ΔY = +0.10 ± 0.01
Sequence diagram of the fully flow-compensated
double-echo SWI sequence5
Image courtesy of Dongmei Wu
FC1
FC2
FC3
Imaging veins and arteries using double echo SWI5
Images courtesy of Meiyun Wang, Zhengzhou
Thrombus dominates the
SWI image (TE = 7.5ms)
Thrombus dominates the
SWIM image (TE = 7.5ms)
First echo MIP
First echo MRA like signal
Second echo (17.5ms) true
SWI
Note the asymmetrically
prominent cortical veins
First echo SWI phase image
Imaging veins and arteries using an interleaved
rephased/dephased double echo SWI6
250μ x 250μ x 500μ resolution
Small arteries around 250 microns and possibly down to even
100 microns are becoming visible
MRA short echo SWI
RP-DP MRA
Simultaneous MRV and
MRI using a double echo
interleaved SWI
rephased/dephased
sequence7
SWI only veins
RP-DP MRA
At 3T, veins are more naturally
suppressed because they
have T2* = 25ms while
arteries have a T2* closer to
70-80ms. Images acquired
with a resolution of 0.5mm x
0.5mm in-plane and 1mm
thick slice.
0.5mm in-plane resolution.
Images courtesy of Yongquan Ye, PhD
MRI scan date: 2013.01.04
MTT
SWI
{
MTT
SWI
MRI scan date: 2013.01.11
Imaging stroke patients
with SWI and PWI8,9:
Note that the MTT region indicating
reduced perfusion matches the area
highlighting the veins in the SWI
image which corroborates the fact
that flow is reduced and that the
deoxyhemoglobin levels are
increased in this territory.
After treatment both the increases
in MTT and evidence of the
asymmetrically prominent cortical
veins disappears.
Images courtesy of Dr. Yu Luo.
Visualizing Oxygen Extraction Fraction and Brain Iron
Green ‐ deoxyhemoglobin levels in the veins
Blue represents iron in the basal ganglia and midbrain
Stroke: Isolating poor flow using a threshold in SWIM9,10
Imaging headache and idiopathic intracranial hypertension
Asymmetrically prominent cortical veins are seen bilaterally
Abnormal dural sinuses and jugular vein
Imaging vessel wall using SWI and SWIM11,12
TE = 15.6ms
0.5mm x 0.5mm x 1mm
sagittal acquisition
8 minutes without
parallel imaging
2008 time frame
0.37 radian phase shift
Carotid vessel wall plaque, TE = 5ms
Carotid artery SWI and SWIM:
Images courtesy of Hyun Seok Choi and Eo-Jin from Seoul, Korea
SWIM
magnitude
MRA
Flow compensated,
TE = 5ms with an
inplane resolution of
0.5mm x 0.5mm and
64 slices 2mm thick
Scan time 4min, 36sec
phase
phase
This may be a case of vulnerable plaque.
Here you can see what appears to be a small thrombus on the inside wall.
If that is the case, it could break off and become an embolus causing a stroke.
SWIM validates it is iron and therefore likely blood.
1st Annual MRI Workshop on Stroke and Traumatic Brain Injury
November 18‐19, 2014 ‐ Shenyang, China
Held at Northeastern University (NEU)
Representatives from the following cities presented:
Academic speakers from Shanghai, Zhengzhou, Tianjin, Shenyang, Seoul, Detroit, and a speaker from Siemens Healthcare from Beijing
AGENDA: GOALS FOR AN INTEGRATED STROKE IMAGING PROTOCOL
• The use of SWI and SWIM in revealing changes in oxygen saturation
• Intracranial black blood T1 imaging pre/post contrast to evaluate atherosclerosis
• Monitoring patients from the acute to sub‐acute stage
• Creating a database for this new 4‐tiered stroke protocol
2nd Annual MRI Workshop on Stroke and Traumatic Brain Injury
• Tentatively scheduled for August, 2015 in Beijing
Conclusions and Future Directions for Non‐contrast Uses of SWI/SWIM
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
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Imaging veins and arteries simultaneously using a multi‐echo SWI sequence
Quantifying oxygen extraction fraction and iron
Imaging vessel wall in the head, neck, abdomen and legs to study atherosclerosis and vulnerable plaque
This talk can be found at www.swim‐mri.com
1) E.M. Haacke, Y. Xu, Y.C.N. Cheng, and J. Reichenbach. Susceptiblity Weighted Imaging (SWI). MRM 2004; 52:612‐618.
2) S. Mittal, Z. Wu, J. Neelavalli, and E.M. Haacke. Susceptibility‐Weighted Imaging: Technical Aspects and Clinical Applications, Part 2. AJNR 2009; 30:232‐252. 3) Haacke EM, Liu S, Buch S, Zheng W, Wu D, Ye Y. Quantitative susceptibility mapping: current status and future directions.Magn Reson Imaging. 2015 Jan;33(1):1‐25. doi: 10.1016/j.mri.2014.09.004.
4) Schweser F, Deistung A, Lehr BW, Reichenbach JR. Differentiation between diamagnetic and paramagnetic cerebral lesions based on magnetic susceptibility mapping. Med Phys. 2010; 37(10):5165‐78.
5) Dongmei Wu, Saifeng Liu, Sagar Buch, Yongquan Ye, Yongming Dai and E. Mark Haacke. A Fully Flow Compensated Multi‐echo Susceptibility Weighted Imaging Sequence: Acceleration and Background Field Effects on Flow Compensation ( manuscript submitted for publication to MRM).
6) Salamon, G., 1971. Atlas of the arteries of the human brain. Sandoz, Paris
7) E.M. Haacke and Y. Ye. The role of susceptibility weighted imaging in functional MRI. Neuroimage. 2012; 62(2):923‐929 PMID: 22245649. 8) M. Li, J. Hu, Y. Miao, H. Shen, D. Tao, Z. Yang, Q. Li, S.Y. Xuan, W. Raza, S. Alzubaidi, and E.M. Haacke. In vivo measurement of oxygenation changes after stroke using susceptibility weighted imaging filtered phase data. PLoS One. 2013 May 13; 8(5): e63013 PMID: 23675450. 9) S. Xia, D. Utriainen, J. Tang, Z. Kou, G. Zheng, X. Wang, W. Shen, E.M. Haacke, and G. Lu. Decreased oxygen saturation in asymmetrically prominent cortical veins in patients with cerebral ischemic stroke. Magn Reson Imaging. 2014 Aug 15. [Epub ahead of print] PMID: 25131626 10) J Liu, S Xia, R Hanks, N Wiseman, EM Haacke, Z Kou. Susceptibility Weighted Imaging and Mapping of Micro‐hemorrhages and Major Veins after Traumatic Brain Injury. Journal of Neurotrauma, 2015, accepted. 11) Q. Yang, J. Liu, S.R.S. Barnes, Z. Wu, K. Li, J. Neelavalli, J. Hu, and E.M. Haacke. Imaging the Vessel Wall in Major Peripheral Arteries using Susceptibility Weighted Imaging: Visualizing Calcifications. JMRI 2009; 30:357‐365. 12) S. Barnes and E.M. Haacke. Settling Properties of Venous Blood Demonstrated in the Peripheral Vasculature Using Susceptibility‐Weighted Imaging (SWI). JMRI 2009; 29:1465‐1470. Imaging macromolecular transport using SWIM
Background

Dr. Satish Kristhnamurthy from Syracuse University has previously
shown that macromolecules (dextran) are transported from the ventricles
into the brain tissue and are rapidly concentrated in the perivascular
space surrounding microvessels throughout the brain.
Hypothesis

These macromolecules are then cleared from the perivascular space
by passing through the endothelium and into the blood (via the
venous system) and are transported out of the brain.
Clearance of iron dextran for a normal rat versus
delayed clearance for the hydrocephalic rat
SWI (TE=7.71ms) at 7T pre, 1 hour and 1h30m for a normal rat (#7) (top
row) and a hydrocephalic rat (#16) (bottom). The hydrocephalic rat has high
Fe-Dextran concentration in the lateral ventricles compared to the normal
rat. The injection side lateral ventricle has higher Fe-dextran concentration.
Susceptibility maps can be used to follow the Fe-Dextran
The timings are pre contrast, 50 minutes (central column) and 1.5h
(right column). The dextran remained in the CSF channels, LV, 3rd
ventricle aqueduct, 4th ventricle and resulted in higher concentration
and permeated to the parenchyma from the CSF channels.
SWIM showed no uptake in normal rats (first row) and significant
uptake in the veins for the hydrocephalic rats over time (second row).