Tomoelastography Distinguishes Noninvasively between Benign and Malignant Liver Lesions

Abstract

Patients with increased liver stiffness have a higher risk of developing cancer, however, the role of fluid-solid tissue interactions and their contribution to liver tumor malignancy remains elusive. Tomoelastography is a novel imaging method for mapping quantitatively the solid-fluid tissue properties of soft tissues in vivo. It provides high resolution and thus has clear clinical applications. In this work we used tomoelastography in 77 participants, with a total of 141 focal liver lesions of different etiologies, to investigate the contributions of tissue stiffness and fluidity to the malignancy of liver tumors. Shear-wave speed (c) as surrogate for tissue stiffness and phase-angle (j) of the complex shear modulus reflecting tissue fluidity were abnormally high in malignant tumors and allowed them to be distinguished from nontumorous liver tissue with high accuracy [c: AUC ¼ 0.88 with 95% confidence interval (CI) ¼ 0.83-0.94; j: AUC ¼ 0.95, 95% CI ¼ 0.92-0.98]. Benign focal nodular hyperplasia and hepatocellular adenoma could be distinguished from malignant lesions on the basis of tumor stiffness (AUC ¼ 0.85, 95% CI ¼ 0.72-0.98; sensitivity ¼ 94%, 95% CI ¼ 89-100; and specificity ¼ 85%, 95% CI ¼ 62-100), tumor fluidity (AUC ¼ 0.86, 95% CI ¼ 0.77-0.96; sensitivity ¼ 83%, 95% CI ¼ 72-93; and specificity ¼ 92%, 95% CI ¼ 77-100) and liver stiffness (AUC ¼ 0.84, 95% CI ¼ 0.74-0.94; sensitivity ¼ 72%, 95% CI ¼ 59-83; and specificity ¼ 88%, 95% CI ¼ 69-100), but not on the basis of liver fluidity. Together, hepatic malignancies are characterized by stiff, yet fluid tissue properties, whereas surrounding nontumorous tissue is dominated by solid properties. Tomoelastography can inform noninvasively on the malignancy of suspicious liver lesions by differentiating between benign and malignant lesions with high sensitivity based on stiffness and with high specificity based on fluidity.Significance: Solid-fluid tissue properties measured by tomoelastography can distinguish malignant from benign masses with high accuracy and provide quantitative noninvasive imaging biomarkers for liver tumors.

Understanding Factors Governing Distribution Volume of Ethyl Cellulose-Ethanol to Optimize Ablative Therapy in the Liver

“…Conducting a similar study in vivo will likely further amplify the superiority of EC-ethanol over pure ethanol. Although healthy liver tissue was used for this study because it is more accessible than tumors, tumors are stiffer and contain necrotic regions that are more brittle, which may make crack formation more likely [59]. Further studies are necessary to investigate the effect of tissue type on injected fluid flow.…”

An analytical solution to the dispersion‐by‐inversion problem in magnetic resonance elastography

“…Magnetic resonance elastography (MRE) measures viscoelastic shear properties of biological soft tissues in vivo using externally induced vibrations at different frequencies to capture the tissue's local harmonic response by motion-sensitive magnetic resonance imaging (MRI). MRE has been proven to be sensitive to many diseases including liver fibrosis, 1 liver tumors, [2][3][4] renal dysfunction, 5 and neuroinflammation. 6 MRE generates parameter maps from time-harmonic shear wavefields using inverse problem solutions.…”

Reduction of breathing artifacts in multifrequency magnetic resonance elastography of the abdomen

“…Abdominal magnetic resonance elastography (MRE) is gaining in importance for the clinical diagnosis of a large variety of diseases that alter the mechanical properties of tissues such as liver fibrosis, [1][2][3][4][5] portal hypertension, 6,7 renal dysfunction, [8][9][10] and tumors. [11][12][13][14] Since the introduction of MRE in 1995 by Muthupillai et al, 15 various MRE methods tailored for clinical examinations of the abdomen have been proposed. 16 A general challenge for abdominal MRE is to cope with respiratory motion during data acquisition, which potentially degrades the consistency of MRE-encoded vibration data.…”

“…26 Nevertheless, there are good reasons for multifrequency MRE of abdominal organs, including measurement of viscoelastic dispersion or improved detail resolution. 25,27,28 For example, tomoelastography, a multifrequency MRE technique for abdominal organs, was applied during free breathing for detecting small hepatic lesions 14 or fine renal structures, 25 despite the risk of breathing artifacts. Although individual images from rapid single-shot MRE scans may have minimal motion artifacts in the organs of interest, intrascan misregistration may degrade the resulting elastograms.…”