advantages overview of clinical to 3 t 3 t imaging
TRANSCRIPT
Overview of Clinical 3 T Imaging
Val M. Runge, MDEditor, Investigative Radiology
Centennial Chair, Scott & WhiteTexas A&M Health Science Center
Advantages to 3 T
Siemens Tim Trio 3 T (S&W)
Siemens Verio 3 T
Brain
Early subacute infarct
Introduction (spatial resolution)
smaller pixel 2:39 min:sec
DWIIPAT 3, 5 mm 24 sec
3 mm 72 sec
Introduction (slice thickness)
Brain
Early subacute infarct
1.5 T 3 T
3 T 3 T
5 mm 5 mm
1 mm2.5 mm
Screening Exam
Brain
3 to 4 mm slices
Short TE GRE T1
T2 FSE
FLAIR DWI
Scan Times (1.5 vs 3 T)
• 3 T (3 mm)
– Pre/post
• T1 sag - 1:16
• DWI axial - 1:33
• T2 axial - 1:32
• FLAIR axial - 2:08
• T1 pre- axial - 1:05
• T1 post- axial - 1:05
• T1 post- cor - 1:05
– Total = 9:44
• 1.5 T (5 mm)
– Pre/post
• T1 sag - 3:00
• DWI axial - 1:04
• T2 axial - 1:36
• FLAIR axial - 4:32
• T1 pre- axial - 2:28
• T1 post- axial - 2:35
• T1 post- cor - 2:49
– Total = 18:04
Contrast Media
Brain
1.5 T
3 T
Gadolinium chelates
3D Time of Flight MRA
Brain
Ophthalmic artery aneurysm
3D Time of Flight MRA
Brain
MCA Aneurysm
1.5 T 3 T
0.8 x 0.4 x 1.0 mm3
vs0.4 x 0.4 x 0.4 mm3 voxel size
AVM
4 mm
TA
1:18
1:52
SWI• There were 22
cerebral cavernous malformations detected by both 3 T HR-SW MRI and standard (1.5T) MRI, in seventeen patients
• 3 T HR-SW MRI detected an additional seven lesions in six patients - all smaller than 0.8 cm in size
Pinker K, Invest Radiol 2007;42:346 Hemorrhage
1.5 T
3 T
Multiple cavernous malformations
2:2
4 v
s 1
:05
m:s
(T1
)
5 mm vs 3
mm
• the effect of magnetic susceptibility increases linearly with field strength
Brain
Medullary infarct
Ischemia
5 mm 1.5 T
3 mm 3 T
Ischemia
Brain
Early subacute infarct
1.5 T 3 T
DWI
Brain
Early subacute pontine Infarct
Ischemia
1.5 T 3 T
5 mm 3 mm
Note the ghost from the superior sagittal sinus
Less partial volume imaging, no ghosting
2:55 vs 1:15 min:sec
BLADE - T2Early subacute
MCA infarct
FSE
BLADE FSE
IPAT = 3
IPAT = 2
MCA infarction
SPACE
Brain
Toxoplasmosis in HIV
Infection/Inflammation
Brain
Cryptococcal meningitis
Infection/Inflammation
Brain
Multiple sclerosis
Brain
1.5 T 3 T
5 mm, TA 3:09 2.5 mm, TA 1:57
Multiple sclerosis
Brain
FLAIR T1 post- contrast
Multiple sclerosis
Toxic/Degenerative Disorders
DWI of CJD
Brain3 mm sections
Congenital Malformations
Schizencephaly
Brain
DWI T2
Neoplasia
Pontine astrocytoma
Brain
TA varied from 24 sec to 59 sec to 2:39 min:sec
spatial (voxel) resolution varied from 0.7 x 0.7 x 5 to 0.5 x 0.4 x 5 to
0.4 x 0.4 x 2.5 mm3
Glioblastoma (multifocal)
Brain
TA 0:59 TA 1:05
TA 0:51
short
TE
2D
GRE
TA 5:22
Scre
enin
g
Finding Small Metastases
Brain
Metastatic non-small cell
carcinoma
1.5 T, 5 mm
3 T, 3 mm
4 mm
TA
2:06
1:18
1:52
1:52
Ruptu
red D
erm
oid
4 mm
3:54
vs
.9x1x1
6:32
SPACE
reformatted
ST = 1.5
Ruptu
red D
erm
oid
Metastases
Brain
Leptomeningeal tumor spread
Brain
Vestibular schwannoma
1.5 T 3 T pre- 3 T post-contrast
0.8 x 0.8 x 2 mm3 0.9 x 0.9 x 3 mm3
Neoplastic Disease - Pituitary
Brain
Prolactinoma
T1 GRE
pre-contrast post-contrast
Brain
Macroadenoma
pre-contrast post-contrast
T1 GRE
Head and Neck
ENT
Ocular metastasis
ENT
Squamous cell
carcinoma
3 mm sections, TA of 1:05 to
1:22
ENT
Squamous cell carcinoma
T2-weighted 3 mm images, TA 1:42
ENT
Glomus jugulare
paragan-glioma
all scans 3 mm slice thickness, TA 1:11 to 1:56
• CE-MRA at 3 T is simply betterclinic patients
IPAT = 4
IPA
T =
2 v
s 4
Courtesy of K. Nael
Caro
tid C
E-M
RA
40
Courtesy of U.
Kramer
Cervical
Spine
Hydromyelia
3 T T2 FSE, 2 mm, TA 2:28
Spine
Hydromyelia
2D T2 GRE 3D VIBE
Cervical
Spine
Multiple sclerosis
1.5 T, 4 mm, TA 5:10 3 T, 2 mm, TA 4:24
Spine
Disc herniation
1.5 T T2 GRE 1.5 T T1 SE
3 T T2 GRE 3 T T1 3D VIBE
4 mm sections with
1 mm gap
2 mm sections with
no gap
TA equivalent
Spine
Disc herniation
T2 2D GRE 2 mm, TA 5:33Spine
Disc herniation
T1 3D VIBE, 2.2 mm, TA 4:43
Disk Herniation
2 mm2:52tse
vs
3 mm3:53fl2d
vs
3 mm4:35fl3d
3 mm
3:53
vs
2 mm
2:52
vs
1 mm
7:08
GRE, TSE vs SPACE
SPACE .7x.7x.7
Dis
k H
ern
iation
Cervicothoracic Junction
Spine
Pancoast tumor
T2 T1post-contrast,
fat sat Spine
Pancoast tumor
3 to 4 mm, TA (for 1 concatenation) of 1:36 to 2:36, 2 concatenations required in each
instance due to a combination of SAR limits and number of slices
Cervicothoracic Junction
Thoracic Cord
Spine
Hydromyelia
T2-weighted FSE T1 FLAIR
TA 2:36 x 2 for all
Spine
1.5 T 3 T
Disc herniation
Spine
T2, 2.4 mm, TA 5:58
Disc herniation
Thin Section Imaging at 3 T
Spine
TA 4:23, 0.6 x 0.5 x 2.4 mm3
Disc herniation, dielectric effect
Spine
T1, TA 4:31, 2 mm
sections
Disc herniation
Conus Medullaris
Spine
1.5 T 1.5 T
3 T 3 T
4 mm, 0.8 mm2
2.4 mm, 0.3 mm2
equivalent TA
Hemangioblastoma
Intrathecal Tumors
Spine
von Hippel-Lindau syndrome
T1 post- contrast
cervical to lumbar images
Thin Section Imaging vs SPACE
Spine
0.6 x 0.5 x 2.4 mm3 0.9 mm3
Hemangioblastoma
SPACE Sagittals
Spine
thin section high resolution 3D images
Composed spine - 2, 4, & 4 mm slice thickness, TA = 1:24, 1:16, & 1:20 min:sec
High resolution lumbar - 0.6 x 0.6 x 2.4 mm3, TA = 5:31
Lepto
menin
geal M
eta
sta
ses
61
AnkleM
usculo
skele
tal M
R
62
Hip
63
Knee
64
Knee
65
Knee
66
Wrist
First Pass Perfusion MRI
671.5 vs 3 T
courtesy of Bernd Wintersperger
Improved SNR at 3 T
CAD, TurboFLASH
683 T
courtesy of Bernd Wintersperger
at rest
adenosine stress
Septal and inferior wall hypoperfusion
LAD occlusion
Cine SSFP at 3 T (Verio)
69normal exam
courtesy of Bernd Wintersperger
Parallel Imaging and Field Strength
70iPAT = 23 vs 1.5 T
courtesy of Bernd Wintersperger
10 heartbeats1.3 x 1.3 x 8 mm
Verio (3 T)
10 heartbeats2 x 1.5 x 8 mm
Avanto (1.5 T)
Left Ventricular Noncompaction
713 T Verio
courtesy of Bernd Wintersperger
Conclusions
• What does 3 T offer (in clinical screening)?
– Higher SNR (which can be used for improved spatial resolution or decreased scan time)
– Increased magnetic susceptibility (improved sensitivity to deoxyhemoglobin and hemosiderin)
– Improved TOF and CE-MRA
• 3 T represents a major advance for diagnostic imaging