Karaciğerin Fokal Lezyonlarının Multiparametrik Mrg ile Değerlendirilmesi

Abstract

JABİYEV A. “Multiparametric Magnetic Resonance Imaging Evaluation of Focal Liver lesions”, Hacettepe University, Faculty of Medicine, Department of Radiology, Thesis in Radiology, Ankara, 2022. The aim of this study is to investigate the importance of liver tissue stiffness and T1-T2 relaxation times in the differentiation of benign and malignant lesions by using magnetic resonance elastography (MRE) and magnetic resonance imaging (MRI) T1-T2 mapping methods in patients with focal lesions in the liver. Patients with focal lesions in the liver who underwent liver MRI and MRE at Hacettepe University Faculty of Medicine, Radiology Department between January 01, 2018 and February 21, 2022 were examined. Lesions were evaluated retrospectively as benign and malignant groups. A total of 70 solid lesions, including 20 benign and 50 malignant lesions, were included in the study. Pre-contrast mean T1 relaxation time in benign lesions is 1474.90 ± 465.39 ms, in malignant lesions 1284.30 ± 351.95 ms, post-contrast mean T1 relaxation time in benign lesions is 629.57±230.92 ms, in malignant lesions 750.20 ± 264.95 msn was measured and no statistically significant difference was found between the benign and malignant lesion groups (p= 0.110 and 0.135). The contrast enhancement ratio, T1 relaxation time reduction and and T1 relaxation time reduction percentage was found to be statistically significantly higher in benign lesions compared to malignant lesions (2,71 ± 0,86 and 1,79 ± 0,52, p= 0,002, 964,00 ± 379,58 and 521,93 ± 290,60, p< 0,001, 59,37 ± 13,32 and 39,79 ± 15,69, p<0,001, respectively). Mean T2 relaxation time was also found to be statistically significantly higher in benign lesions compared to malignant lesions (82.50 ± 23.29 ms and 65.02 ± 15.38 ms, p= 0.005). Mean stiffness values on MRE imaging were statistically significantly higher in malignant lesions compared to benign lesions (5.43±1.55 kPa and 3.62±1.16 kPa, p=0.004). ADC mapping values in diffusion-weighted imaging were found to be statistically significantly higher in malignant lesions compared to benign lesions (1688.17 ± 270.04 and 1177.94 ± 443.25, p= 0.001). In ROC analysis, 1.99 cut-off value for CER (AUC: 0.852, sensitivity 78.6% and specificity 78.3%), 749.5 ms cut-off value for T1D value (AUC 0.817, sensitivity 71.4% and specificity 78%), 49.71% cut-off value for T1D% value (AUC 0.831, sensitivity 78.6% and viii specificity 73.2%), 74 ms cut-off value for mean T2 relaxation time value (AUC 0.705, sensitivity 65% and specificity 76.6%), 3,74 kPa for mean stifness value ( AUC 0.848, sensivity 85% and spesificity 75%) and a cut-off value of for ADC mapping value (AUC 0.854, sensitivity 75% and specificity 74,3%) were determined for differentiation of malignant lesions from benign ones. T1-T2 mapping and MRE imaging methods can be used as non-invasive alternative tools to differentiate solid focal lesions of the liver from benign and malignant lesions. Keywords: Liver focal lesions, benign, malignant, MR elastography, T1-T2 mapping.