Diagnostic concordance between the simple T1 sequence and the gadolinium T1 sequence, in brain magnetic resonance imaging

Abstract

Objective: to determine the diagnostic concordance between the simple T1 sequence and the T1 sequence with gadolinium in brain magnetic resonance imaging, at the Lenin Fonseca School Hospital, between November 2019 and November 2020.

Material and method: correlational study. The study population was 110 patients, with images of simple T1 and T1 with gadolinium, obtained with a 0.35 Tesla magnetic resonator, SiemensMR, Magnetom C. Simple random probability sampling was applied.

Results: the intra-observer agreement had a Kappa index=1.0 for both radiologists p<0,05. The inter-observer agreement presented a Kappa index=0,95 for radiologist 1 and 0.97 for radiologist 2 p<0,05. The simple T1 sequence was conclusive for radiologist 1 in (72) cases 65% and in (79) cases 72% for radiologist 2. The T1 sequence with gadolinium was conclusive in (109) cases 99% for radiologist 1 and in (110) 100% for the radiologist 2.

Conclusions: The intra-observer agreement was perfect and statistically signifi cant when evaluating the simple T1 and T1 sequences with gadolinium. The inter-observer agreement was almost perfect and statistically signifi cant. The simple T1 sequence presents a higher percentage of inconclusive or doubtful studies than the T1 with gadolinium, so the research hypothesis is accepted. If the intra-observer agreement was perfect and the inter-observer almost perfect, one of the two sequences can be dispensed with. Simple T1 could be used selectively, due to the advantage of gadolinium enhancement in detecting abnormalities.

Keywords: magnetic resonance imaging, gadolinium, simple T1 sequence, gadolinium T1 sequence, concordance index.