Evaluation of contrast-enhanced FLAIR sequence in MR assessment of intracranial tumours.

BACKGROUND

Magnetic resonance (MR) has become the most important imaging method in the diagnosis of intracranial tumours. However, conventional MR protocol often fails to obtain all morphological details which are necessary for precise planning of the treatment. Therefore, there are attempts of introducing other MR techniques, to gain new information concerning tumour morphology. One such technique is FLAIR sequence. In previous papers we presented the value of plain FLAIR in patients with intracranial tumours. The aim of the present study was evaluation of contrast enhanced FLAIR (CE FLAIR) in assessment of intracranial tumours.

MATERIAL/

METHODS

MR examinations, including conventional T1 (pre-and postcontrast) and T2 images, as well as plain and contrast-enhanced FLAIR sequences were performed in 27 patients with intracranial tumours. In all patients the degree and localization of contrast enhancement in post-contrast T1-weighted sequence (CE T1w) and CE FLAIR images have been compared.

RESULTS

Contrast enhancement of the tumour in both CE T1-w and CE FLAIR sequences was found in 18 patients. In 5 patients the enhancement was visible only on T1-weighted images, while in 2 cases only on FLAIR images. Among 18 patients, who demonstrated enhancement both in T1-weighted and FLAIR sequences, in 9 cases the effect of enhancement was better on T1-weighted images, in 7-CE FLAIR gave superior results, and in 2 patients - both methods were equivalent. In the whole material in 9 cases CE-FLAIR was superior in 14-inferior and in 4-equal to CE-T1-w. Among 9 cases in which CE- FLAIR was superior, in 7 patients the enhancement concerned the border of the tumour or postoperative cave.

CONCLUSIONS

Contrast-enhanced FLAIR has limited value in assessment of intracranial tumours and should be used as a supplementary technique if there are difficulties in evaluation of tumour morphology in other sequences.