Dados do Trabalho

Título

Optimization of Hepatic Multiparametric Magnetic Resonance Protocol: A Comprehensive Approach to Assessing Liver Composition and Stiffness

Introdução e objetivo(s)

Hepatic multiparametric magnetic resonance imaging (mpMRI) is a non-invasive diagnostic protocol that enables liver evaluation, combining advanced techniques, including fat fraction (FF) quantification, iron content using T2-mapping (T2m), and hepatic elastography (MRE). Each component offers unique information, contributing to a more accurate diagnosis of hepatic disorders, in less than 4 minutes.

Método(s)

This study summarizes the optimization of the hepatic mpMRI protocol in 62 patients on a 3T MRI system, following a medical indication for liver evaluation (Fig. 1). The imaging protocol included a gradient echo sequence (GRE) with variable echo times for T2m, a three-point DIXON sequence for FF quantification, and a 2D phase-contrast GRE for MRE. All sequences were acquired using strict geometries in an axial plane, minimizing gradient load and ensuring data consistency across imaging modalities. The DIXON sequence separates water and fat signals, providing accurate FF quantification (Fig. 2), with adjustments made for low signal-to-noise ratios by reducing matrix size depending on the specific pathology. T2m was evaluated for T2* values, with emphasis in echo adjustments to ensure proper mapping (Fig. 3). The quality of T2m was validated through visual assessment of image noise and, if necessary, post-processing corrections (Fig. 4). MRE provided liver stiffness measurements by assessing the propagation of mechanical waves through hepatic tissue (Fig. 5).

Discussão

The mpMRI protocol provides a non-invasive tool for assessing liver pathophysiology. T2m allows evaluation of hepatic iron content, critical for diagnosing conditions like hemochromatosis and iron overload. FF quantification is integral in identifying hepatic steatosis, a hallmark of non-alcoholic fatty liver disease. Hepatic MRE quantifies liver stiffness, offering information for detecting fibrosis and cirrhosis. By integrating these techniques into a fast unified imaging protocol, diagnostic accuracy is enhanced, providing a comprehensive understanding of liver health and facilitating early intervention for liver diseases.

Conclusões

This protocol is a reliable tool for liver assessment. By combining T2m, FF quantification, and MRE, this approach provides a detailed evaluation of liver composition and stiffness, aiding in the diagnosis and management of various hepatic conditions. This technique improves diagnostic precision and offers valuable insights into liver health, making it an indispensable tool in clinical hepatology.

Palavras Chave

Hepatic Imaging; MAGNETIC RESONANCE IMAGING; multiparametric protocol

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