J Korean Radiol Soc.  1998 Mar;38(3):397-401. 10.3348/jkrs.1998.38.3.397.

MR Imaging with FLAIR Pulse Sequence in Various Cerebral Lesions: Comparison with T2-Weighted Imaging

• Lee YJ
• Han CH
• Lee JC
• Kim ST
• Oh GY
• Cho SW
• Lee SK
• Lee JH

• KMID: 2201392
• DOI: http://doi.org/10.3348/jkrs.1998.38.3.397

Abstract

PURPOSE: To evaluate the utility of fluid-attenuated inversion recovery(FLAIR) sequence by comparing thesignal intensities in various cerebral lesions with those on T2-weighted MR imaging. MATERIALS & METHODS: In 41patients who showed different signal intensities between T2-weighted images and FLAIR sequences, we reviewed theVirchow-Robin space(VRS), acute or chronic infarctions including lacunar cavities, and postoperativeencephalomalacia. In all patients, the location, shape and size of abnormal signal intensities were evaluated.
RESULTS
The hyperintensities of VRS and lacunar infarctions on T2-weighted imaging appeared as hypointensitieson FLAIR imaging. The hyperintense rims or crescents around lacunar cavities were only detected on FLAIR imaging.The extent of acute and chronic infarctions with homogenous hyperintensities seen on T2-weighted images was welldelineated on FLAIR imaging. Postoperative encephalomalacia and adjacent lesions showed low and high signalintensities, respectively, on FLAIR imaging, though they were hyperintense on T2-weighted images.
CONCLUSION
ForVRS, infarction and encephalomalacia, FLAIR provides images that are superior to T2-weighted images, and may thusbe useful as an additional MR sequence in various cerebral lesions.

Keyword

Brain, MR; Brain, diseases; Magnetic resonance(MR), sequences

MeSH Terms

Encephalomalacia
Humans
Infarction
Magnetic Resonance Imaging*
Stroke, Lacunar

Figure

• 

  Fig. 1. Dilated perivascualr space and ischemic lesions in 76-years-old man. A. Axial Τ 2-weighted MR image shows multiple variable-shaped hy- perintense lesions in both basal ganglia(small & large arrows). B. FLAIR image shows tubular or ovoid hypointense perivascualr spaces (solid arrows) and round hypointense lacunar infarction with peripheral hyperintensity(open arrow). The linear hyperintense ischemic lesion at the posterior aspect of left basal ganglia, which is seen in jig. 1A appears hyperintense(arrowhead- s) on FLAIR image.

• 

  Fig. 2. Lacunar infarction in 80- years-old woman. A. Axial Τ2-weighted image shows two round hyperintensities in left basal ganglia and right thalamus (arrows). B. FLAIR image shows small low signal intensities with hyperintense rim or crescent(arrows).

• 

  Fig. 3. A 88-years-old woman with acute and chronic cerebral infarctions. A. Axial T2-weighted image shows cerebral infarctions in left frontal and parietal lobes, and right occipital lobe(arrows). B. On FLAIR image, the extent of acute(open arrows) and chronic (solid arrows) infarctions is well delineated.

• 

  Fig. 4. A 80-years-old woman with postoperative state of hematoma. A. Axial T2-weighted image shows huge hyperintense lesion in right frontal and temporal lobes(black and white arrows). B. On FLAIR image, brain tissue loss(white open arrows)and peripheral hyperintensity (black arrows) in the posterior aspect of the main lesion are seen.

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