Dados do Trabalho

Título

Quantification of T2 mapping, Fat Fraction and Diffusion Magnetic Resonance biomarkers for spondyloarthropathy.

Descrição sucinta do(s) objetivo(s)

Parameterizing quantitative biomarkers in the study of spondyloarthropathy (SpA) aimed to the analysis of bone marrow edemas (BMEs) through the measurement of T2 mapping (T2m), Dixon Fat-Fraction sequence (FF) and Apparent Diffusion Coefficient (ADC), can improve the diagnosis and follow-up of this diseases at musculoskeletal protocols. The aim of this work is to study the T2m, FF, and ADC values to evaluate their performance in the SpA characterisation of BMEs.

Material(is) e método(s)

The acquisition was performed on a 1.5 T scanner in 21 patients (53 +- 7 y/o) and consisted in both a STIR and T1w anatomical sequences (axial and coronal) of the sacroiliac bones, followed by a T2m, FF, and ADC (Fig. 1). Two expert radiologists delimited VOIs corresponding to BMEs and healthy tissue (Fig. 2); for each region a segmentation was implemented in order to obtain quantifications and the STIR images were used as the anatomical reference for BMEs identification, these were merged with the corresponding T2m and FF slices for visualization purposes (Fig. 3). Tests were performed on the collected data, a ROC curve for T2m (Fig. 4) and FF (Fig. 5) were generated and cut-off values were determined.

Resultados e discussão

The obtained p-values were the following: p<0.001 (T2m) , p=0.025 (FF) and p>0.1 (ADC). A T2 relaxation time of 63.5ms and FF 63.50% were the corresponding cut-off values for the FF and a T2 time of 104 ms for the T2m sequence. A bigger patient cohort is needed and due to the effects of bone aging in the population, future studies will have to separate the patients into different age groups. Furthermore the extra acquisition time should be taken into account when deciding to add these extra sequences.

Conclusões

T-tests showed a statistical significant difference when comparing BMEs and normal tissue in the sequences and the cut-off values were found to be reliable biomarkers differentiators for BMEs, particularly for T2m. The ADC analysis did not show statistically significant differences. The T2m and FF quantifications can be an useful tool for radiologists and clinicians alike in the volume measurement, follow-up and control of patients that present some type of SpA.

Palavras Chave

MAGNETIC RESONANCE IMAGING; spondyloarthropathy

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