T1 inversion recovery pulse sequence: could it replace T1 spin echo sequence in neuroimaging by improving tissue contrast?

Abstract

Background: T1 inversion recovery (T1IR) sequence improved tissue contrast by providing higher gray matter-white matter contrast ratio (GM-WM contrast ratio) and higher lesion contrast noise ratio (CNR). This study aims to highlight its significance in the evaluation of space-occupying lesions whether intra-axial or extra-axial and also in multiple sclerosis (MS) by comparing it with T1 spin echo (T1SE) sequence. Result: In a total of 50 patients, 14 patients with extra-axial lesions, 18 patients with intra-axial lesions, and 18 patients with multiple sclerosis were included. The CNR was significantly higher for pre-contrast T1IR images than for pre-contrast T1SE (− 13.04 (1.20) vs − 7.73 (0.70); p value < 0.01). After giving intravenous contrast media, CNR in T1SE was higher than T1IR (11.14 (1.75) vs 9.41 (1.83)) without statistical significance (p value = 0.19) and CNR was higher in T1IR than T1SE in lesions with low enhancement ratio (ER). As well, the overall number of lesions was higher on T1IR especially in MS (10.67 (2.26) vs 3.89 (1.05); p value < 0.01). Conclusion: On pre-contrast sequences, T1IR could be used as an added sequence in most brain lesions giving higher lesion CNR. After giving intravenous contrast media, T1IR could be used in lesions with low ER. It also could be used in situations in which gadolinium injection is contraindicated and also could be used in follow-up of MS patient by detecting a higher number of lesions that can be easily missed in T1SE.