Mungunkhuyag Majigsuren1,2, Takashi Abe2, and Masafumi Harada2
1Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia, 2The University of Tokushima, Tokushima, Japan
Synopsis
We
compared the gadolinium enhancement characteristics of a heterogeneous population
of brain tumors imaged by T1-Cube and 3D FSPGR at 3T MRI with time-dependent
changes. A totally 91 lesions from 52 patients with brain tumors in 3T MRI. Fifty-one
of the 91 lesions (56.04%) were depicted with T1-Cube first, and 40 lesions
(43.96%), with 3D FSPGR first. 3D FSPGR images would be expected to exhibit
greater enhancement than T1-Cube images. However, the overall mean CNR values were
higher on T1-Cube images with both order sequences. We suggest the superiority
of T1-Cube to 3D FSPGR for the detection of metastatic lesions.
BACKGROUND
AND PURPOSE: T1-Cube (GE HealthCare) is a relatively new 3-dimensional (3D)
fast spin echo (FSE)-based magnetic resonance (MR) imaging sequence that uses a
variable flip angle to acquire gap-free volume scans.1 We compared
the gadolinium enhancement characteristics of a heterogeneous population of
brain tumors imaged by T1-Cube and 3D fast spoiled gradient recall acquisition
in steady state (3D FSPGR) at 3-tesla MR imaging with time-dependent
changes.
MATERIALS
AND METHODS: A totally 91 lesions
from 52 patients with brain tumors ((17 patients with metastasis (51 lesions), 17
with high grade glioma (HGG, 19 lesions), 7 with primary central nervous system
(CNS) lymphoma (10 lesions), and 11 with meningioma (10 meningiomas and one
hemangiopericytoma)), the two sequences in 3T MRI
(Discovery 750, GE Healthcare, Milwaukee, WI) were examined after administration
of contrast agent (Gd-DTPA, 0.1 mmol/kg). Scan parameters for T1-Cube images
(TR/TE 500 ms/15.1ms, bandwidth 50 kHz, slice thickness 1.2 mm, matrix 384x256, echo
train length 18, flip angle 15, number of excitation 1, FOV 24x24 cm,
acceleration factor 2x2, number of slices 160, scan time 4 minutes 5 seconds. Scan
parameters for 3DSPGR images (TR/TE 10.4 ms/4.4ms, bandwidth 31.25 kHz, slice
thickness 1.2 mm,
matrix 384x256, flip angle 15, number of excitation 1, FOV 24x24 cm,
acceleration factor 2x2, number of slices 160, scan time 3 minutes 34 seconds. Fifty-one
(metastasis 32, HGG 11, meningioma 5, PCNSL 3) of the 91 lesions (56.04%) were
depicted with T1-Cube first, and 40 (metastasis 19, HGG 8, meningioma 6, PCNSL
7) lesions (43.96%), with 3D FSPGR first. We measured the contrast-to-noise ratio
(CNR) which is the signal intensity (SI) of a tumor and normalized by SI of the
white matter for each sequence on the pre and post contrast 3D FSPGR and post
contrast T1-Cube images. Two neuroradiologists measured ROIs (a hand-drawn
polygonal ROI was defined as large as possible contrast enhanced area to exclude
necrotic areas of the lesion) twice separately.
RESULTS:
The mean CNR was significantly higher on T1-Cube images than 3D FSPGR images
for the total tumor population (2.23±1.4; 1.99±1.55; P<0.0001) and the histologic
types, i.e., metastasis (2.36±1.62; 2.02±1.58; P < 0.001) and HGG (1.79±0.89;
1.34±0.71; P < 0.05). By the analysis concerning with sequence order, the
first T1-Cube: mean CNR was slightly larger (2.18±0.73; 2.12±0.67; P<0.0001)
and the first 3D FSPGR: mean CNR significantly higher (2.28±0.16; 1.82±0.42;
P<0.014) on T1-Cube images than on 3D FSPGR images. The difference in mean CNR
was both of larger (56.3-1094.3 mm2; 2.12±1.47±1.07; P<0.05) and smaller
(10.6-50.7 mm2; 2.60±1.71; 2.49±1.80; P<0.011) tumors in the
metastatic group.
DISCUSSION:
Previous studies, reported that the CNR of brain metastasis on SPACE was
significantly higher than that for MPRAGE at 3T MRI.1-2 In this study,
we acquired T1-Cube images before and after 3D FSPGR images because a longer
delay after injection of contrast agent results in greater enhancement, so 3D
FSPGR images would be expected to exhibit greater enhancement than T1-Cube
images. However, the overall mean CNR value and most tumor subtype mean CNR
values were higher on T1-Cube images with both order sequences.
CONCLUSION:
Gd enhancement of the same heterogeneous population of tumors was higher using
T1-Cube than 3D FSPGR, and suggest the superiority of T1-Cube to 3D FSPGR for the
detection of metastatic brain lesions.
Acknowledgements
No acknowledgement found.References
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Kato Y, Higano S,
Tamura H, et al. Usefulness of contrast-enhanced T1-weighted sampling
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J Neuroradiol 2009;30:923-29
2.
Komada T, Naganawa
S, Ogawa H, et al. Contrast-enhanced MR Imaging of metastatic brain tumor at 3
tesla: utility of T1 -weighted SPACE
compared with 2D spin echo and 3D gradient echo sequence. Magn Reson Med
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