Transcript Evaluating Marrow Signal Intensity

Comparison of T1 FLAIR and T1
FSE Images
Andrew Allmendinger, DO
Sylvie Destian, MD

Neither I nor my immediate family members
have a financial relationship with commercial
organizations that may have a direct or
indirect interest in the content of this
presentation.

In most institutions, a sagittal T1
FLAIR sequence has replaced the
T1 FSE in routine MR imaging of
the lumbar spine.


Faster
Provides better conspicuity of
abnormalities in the cord, CSF, disc,
and bone1,2,3.
1Erdem
LO, Erdem CZ, Acikgoz B, Gundogdu S. Degenerative disc disease
of the lumbar spine: a prospective comparison of fast T1-weighted fluidattenuated inversion recovery and T1-weighted turbo spin echo MR imaging.
Eur J Radiol, 2005 Aug; 55(2):277-82
2Lavdas
E, Vlychou M, Arikidis N, Kapsalaki E, Roka V, Fezoulidis IV.
Comparison of T1 weighted fluid-attenuated inversion recovery images of the
lumbar spine at 3.0 Tesla. Acta Radiol 2010 Apr; 51(3):290-5.
3Melhem
ER, Israel DA, Eustace S, Jara H. MR of the spine with a fast
T1-weighted fluid-attenuated inversion recovery sequence. AJNR 1997
Mar;18:447-454.
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

T1 FLAIR = T1 FSE?
To determine whether there is a
difference in the appearance of the
marrow signal on T1 FLAIR and T1
FSE images in normal individuals
To determine whether the difference
is related to age.

Sagittal T1 FLAIR


TE 22, TI 500, TR 2000, Echo Train 12, Freq
448, Phase 224, NEX 2, Slice thickness 4/1,
Freq encoding A/P, imaging options: NPW,
scan time 2:16
Sagittal T1 FSE

TE minimum full, TR 650, Echo Train 2, Freq
256, Phase 192, NEX 2, Slice thickness 4/1,
Freq encoding A/P, imaging options: FC,
NPW, TRF, FAST, scan time 3:14

1.5T GE Signa /Excite

Prospective study

All patients having non contrast
MRI of the lumbar spine during a
3 month period in 2009 (n=217).
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Exclusion criteria:



older than 75 years
prior lumbar surgery
predisposing medical condition
 HIV disease
 multiple myeloma
 osteoporosis
 metastatic disease
 renal failure
 severe degenerative disease

Final n=93
A
B
A midline sagittal T1 FLAIR and T1 FSE
image from each exam, randomly labeled “A”
or “B”, were placed side by side in a power
point presentation.


All case pairs were reviewed by 3
board certified radiologists, each
with more than 5 years experience
in MR imaging.
The radiologists compared the two
images and were asked whether


marrow signal intensity = or difference
perceived?
T1 FLAIR or T1 FSE darker?
A
B
The marrow signal intensity appears lower
on the T1 FLAIR image (A), compared to
the T1 FSE image (B) on the right.
A
B
The marrow signal intensity appears lower
on the T1 FSE image (A) compared to the
T1 FLAIR image (B) on the right.
A
B
The marrow signal intensity on the T1
FSE image (A) and the T1 FLAIR
image (B) appears equal.
Age
0 to 10
11 to 20
21 to 30
31 to 40
41 to 50
51 to 60
61 to 70
71 to 75
Total (n=70)
T1 FLAIR Darker
0
0
7
11
11
13
6
6
54
T1 FSE Darker
0
0
3
3
1
3
6
0
16
Where a difference was perceived, the
marrow signal intensity was judged darker
on T1 FLAIR 77% of the time (p < .0001).
Age
T1 FLAIR Darker
0 to 10
0
11 to 20
0
21 to 30
7
31 to 40
6
41 to 50
5
51 to 60
4
61 to 70
6
71 to 75
4
Total (n=35)
32
T1 FSE Darker
0
0
1
0
0
1
1
0
3
Where a difference was perceived, the
marrow signal intensity was judged darker
on T1 FLAIR 91% of the time (p < 0.0001).
Age
0 to 10
11 to 20
21 to 30
31 to 40
41 to 50
51 to 60
61 to 70
71 to 75
Total (n=87)
T1 FLAIR Darker
0
1
12
16
15
20
15
6
85
T1 FSE Darker
0
0
1
0
0
0
1
0
2
Where a difference was perceived, the
marrow signal intensity was judged darker
on T1 FLAIR 98% of the time (p < .0001).
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

T1 FLAIR and T1 FSE were judged
equal in 31% of the cases.
When a difference was perceived,
the T1 FLAIR image was judged
darker in 88% of the cases.
T1 FLAIR was judged darker in all
age groups from 21-75.

1 patient < 20 years

One radiologist


Two radiologists


T1 FLAIR darker
T1 FLAIR = T1 FSE
More data needed 0-20 age group


Regardless of age, marrow signal
intensity on T1 FLAIR images may
appear artificially low in normal
individuals.
It is important to recognize this
potential pitfall in order to avoid
misdiagnoses and/or additional
unnecessary exams.