Leonard Sunwoo1,2, Tae Jin Yun2,3, Roh-Eul Yoo2,3, Soo Chin Kim2,4, and Hye Young Sun2,4
1Radiology, Seoul National University Bundang Hospital, Seongnam, Korea, Republic of, 2Seoul National University College of Medicine, Seoul, Korea, Republic of, 3Radiology, Seoul National University Hospital, Seoul, Korea, Republic of, 4Radiology, Seoul National University Healthcare System Gangnam Center, Seoul, Korea, Republic of
Synopsis
Arterial
spin labeling (ASL) magnetic resonance (MR) imaging could be used to assess the
tumor blood flow (TBF). To distinguish glioblastoma (GBM) from brain
metastasis, we compared TBF between the two groups by using visual grading and
quantitative analyses. Both intratumoral and peritumoral blood flow were
significantly higher in GBM than in brain metastasis. We propose that ASL-TBF
can aid in differentiating GBM from brain metastasis either by qualitative or
by quantitative methods.Purpose
The
aim of this study is to compare ASL-TBF in GBM with that in brain metastasis by
using qualitative and quantitative analysis.
Methods
The
study was approved by the institutional review board. The study population
consisted of 128 consecutive patients who underwent surgical resection and were
diagnosed either as GBM (n = 89) or as brain metastasis (n = 39). All
participants underwent preoperative MR imaging including ASL.
Two
reviewers blinded to patient history and pathologic data reviewed
randomly-ordered MR image sets. For qualitative analysis, reviewers graded the
lesions based on the degree of hyperintensity of ASL images using the following
criteria: 1) no hyperintensity; 2) minimal hyperintensity; 3) mild
hyperintensity; 4) moderate hyperintensity; and 5) strong hyperintensity.
For quantitative analysis, reviewers drew regions
of interest (ROIs) on ASL images upon the most hyperintense portion within the
tumor (intratumoral ROI) and upon the peritumoral T2 hyperintensity area
(peritumoral ROI). Signal intensities of intratumoral and peritumoral ROIs for
each subject were normalized by dividing the values by those of contralateral
normal gray matter (nTBFmax and nTBFperi, respectively).1,2
We compared visual grading scales and quantitative parameters between GBM and
brain metastasis.
Results
The
overall agreements between the two reviewers were excellent. In terms of
qualitative analysis, GBM group showed significantly higher grade compared to
metastasis group (
P = .001).
With regard to quantitative analysis, both nTBF
max and nTBF
peri
were significantly higher in GBM than in metastasis (
P < .001). The areas under the
curve from receiver operating characteristics analysis were 0.677, 0.714, and
0.835 for visual grading, nTBF
max, and nTBF
peri,
respectively (all
P < .001).
Representative images are shown in Fig. 1.
Conclusion
Intratumoral
or peritumoral blood flow on ASL can aid in differentiating GBM from brain
metastasis.
Acknowledgements
No acknowledgement found.References
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T, Hiwatashi A, et al. Perfusion imaging of brain tumors using arterial
spin-labeling: correlation with histopathologic vascular density. AJNR Am J
Neuroradiol. 2008;29(4):688-693.
2. Jarnum H, Steffensen EG, Knutsson L, et al. Perfusion MRI
of brain tumours: a comparative study of pseudo-continuous arterial spin
labelling and dynamic susceptibility contrast imaging. Neuroradiology.
2010;52(4):307-317.