Contrast enhanced FLAIR versus contrast enhanced T1W images in evaluation of intraparenchymal brain lesions

Abstract

Background Patients with suspected brain lesions are usually evaluated by means of intravenous contrast materials. These lesions may demonstrate enhancement through different mechanisms. At most institutions, CE-T1WI is the preferred sequence. FLAIR is a sort of inversion recovery pulse sequence with a long TR, TE and T1 and hence effectually nulls signals from CSF. The long T1 causes mild T effect and this result in lesion enhancement on post-contrast study. Therefore, lesions demonstrating enhancement on CE-T1WI will also demonstrate enhancement on CE-FLAIR images. The purpose of this work was to assess the role of CE-FLAIR versus CE-T1WI in evaluation of different intraparenchymal brain lesions. Results Comparing CE-T1WI to CE-FLAIR in various brain pathologies, both observers found higher sensitivity and specificity for lesion to background contrast ratio on CE-FLAIR comparing to CE-T1WI. Observer 1 found that lesion to background contrast ratio on CE-FLAIR had sensitivity of 71.4%, specificity of 66.7% and AUC of 0.661 versus 63.3% sensitivity, 58.3% specificity and 0.634 AUC for CE-T1WI. Observer 2 found that lesion to background contrast ratio on CE-FLAIR had sensitivity of 77.6%, specificity of 66.7% and AUC of 0.719 versus 61.2% sensitivity, 50% specificity and 0.628 AUC for CE-T1WI. Conclusion On comparing CE-FLAIR to CE-T1WI, CE-FLAIR display better lesion detection and enhancement also better soft tissue contrast resolution.

Diagnostic Utility of Contrast-Enhanced Fluid-Attenuated Inversion Recovery Magnetic Resonance Imaging in Intracranial Pathologies: Qualitative and Quantitative Analyses

“…This allowed us to detect disease activity and, as a result, provided a chance for better patient management. This was consistent with the findings of a prior study by EL Adalany et al [10], who discovered that CE-FLAIR images had more enhancing lesions than CE-T1WI images did, particularly in cases of multiple sclerosis (MS), where CE-FLAIR outperformed CE-T1WI in 90% of the cases. These findings were in good accord with another study [19] that evaluated CE-FLAIR against CE-T1WI, DWI, and ADC and found that CE-FLAIR was the most effective in active MS lesions due to its ability to attenuate the CSF signal and boost the detection of lesions.…”

“…Additionally, we discovered that CEFLAIR allowed for better lesions definitions than CET1I in 54% and 46% of cases, respectively, with good agreement between their results (kappa 0.744). EL Adalany et al, reported in a prior study [10] that in 68.9% of the instances, CE-FLAIR pictures exhibited better lesion conspicuity than CE-T1WI, with good interobserver agreement found (Kappa = 0.848). In contrast to a study by Athar I, et al [17], which indicated a lower percentage (39.4%) of cases with better lesions conspicuity in CEFLAIR, our study and the study by EL Adalany et al The quantitative analysis of our cases revealed that the lesions' signal intensity (SI) was higher on CE-FLAIR images than it was on pre-contrast ones, confirming the existence of lesion enhancement on CE-FLAIR images.…”

“…It was done by using a region of interest (ROI) to calculate the SI of the lesion in both pre-and post-contrast FLAIR images. The following was used in the calculation: ˆ ˆ I = I − I0 (I is CEI, I is the lesion SI on CE-FLAIR images and I0 is the lesion SI on pre-contrast FLAIR images) [10].…”

“…The lesion to background contrast ratio was calculated by: Lesion to background contrast ratio = Lesion SI − Background SI/Back-ground SI [10].…”