Liver

 

Liver parenchyma should be affected by several focal or diffuse disease and imaging plays a leading role in the characterization of different pathologies and planning the most appropriate therapies.

For the detection and characterization of focal liver lesions, Magnetic Resonance (MR) has been demonstrated to be the most accurate imaging modality especially when liver specific contrast agent is used. Also liver MR diffusion is a validated tool for the detection of malignant focal lesion, in particular liver metastases [1-4].

Post-processing analysis on liver images can be helpful for surgeons in order to evaluate tumor resection and assessment of percentage of remnant liver and for oncologist to quantify tumor response to chemiotherapy (Figure.1).

 

 

 

 

 

 

 

 

 

Figure.1(A-B) Preoperative evaluation of tumor resectability which highlighted the percentage of future liver remnant that should be greater than 40%. (C) Follow-up of patients with liver metastases at baseline and after chemiotherapy.

 

 

 

 

MR is also considered the most accurate tool for quantification of liver steatosis; PDFF-MR enables with a single scan acquisition the right estimation of fat percentage into liver parenchyma. The same technique cited above is used for the calculation of R2* that reflects the presence of iron storage (Figure.2)[5-6].

Figure.2 Fat Fraction Maps obtained from healty patients (A) and with metabolic syndrome (B), show different percentage of liver steatosis.

 

Application of radiomics on liver imaging are focused on differentiation of histological grade of liver tumors and prognostic assessment of response to therapy (Figure.3)[7].

Figure.3 Radiomics for non-invasive differentiation between Low-Grade (A) vs High-Grade (B) hepatocellular carcinoma 

 

 

 

 

References

 

  1. Marin D, Di Martino M, Guerrisi A, et al. Hepatocellular carcinoma in patients with cirrhosis: qualitative comparison of gadobenate dimeglumine-enhanced MR imaging and multiphasic 64-section CT. Radiology. 2009 Apr;251(1):85-95.
  2. Di Martino M, Marin D, Guerrisi A, et al. Intraindividual comparison of gadoxetate disodium-enhanced MR imaging and 64-section multidetector CT in the Detection of hepatocellular carcinoma in patients with cirrhosis. Radiology. 2010; 256: 806-1
  3. Goshima S, Kanematsu M, Kondo H, et al. Diffusion weighted imaging of the liver: optimizing b value for the detection and characterization of benign and malignant hepatic lesions. J Magn Reson Imaging 2008; 28: 691–697
  4. Di Martino M, Di Miscio R, De Filippis G, et al. Detection of small (≤2 cm) HCC in cirrhotic patients: added value of  diffusion MR-imaging. Abdom Imaging. 2013; 38: 1254-62
  5. Di Martino M, Pacifico L, Bezzi M, et al. Comparison of magnetic resonance spectroscopy, proton density fat fraction and histological analysis in the quantification of liver steatosis in children and adolescents. World J Gastroenterol. 2016; 22: 8812-8819
  6. Diagnostic accuracy of hepatic proton density fat fraction measured by magnetic resonance imaging for the evaluation of liver steatosis with histology as reference standard: a meta-analysis Yali Qu Mou Li Gavin Hamilton et al.  Eur Radiol 2019; 29: 5180-5189.
  7. Oh J, Lee JM, Park J, Joo I, Yoon JH, Lee DH, Ganeshan B, Han JK.   Hepatocellular Carcinoma: Texture Analysis of Preoperative Computed Tomography Images Can Provide Markers of Tumor Grade and Disease-Free Survival. Korean J Radiol. 2019; 20: 569-579

 

© Università degli Studi di Roma "La Sapienza" - Piazzale Aldo Moro 5, 00185 Roma