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Postmortem Radiology and Digital Imaging
Published in Cristoforo Pomara, Vittorio Fineschi, Forensic and Clinical Forensic Autopsy, 2020
Giuseppe Bertozzi, Francesco Pio Cafarelli, Andrea Giovanni Musumeci, Giulio Zizzo, Giampaolo Grilli, Cristoforo Pomara
However, the need to compare PMMRI with histopathology has led to some studies. Absinta et al., in fact, have shown that compared to standard sectioning, the use of a PMMRI of whole brains fixed in formalin in order to drive the subsequent sampling has improved the speed, quality, and accuracy of the radiological–pathological correlations. Furthermore, the use of magnetic resonance elastography (MRE) for noninvasive evaluation of the viscoelastic properties of brain tissue demonstrates no or minimal significant difference between in vivo and 24 hour postmortem.
Functional imaging and emerging techniques in MRI
Published in Anju Sahdev, Sarah J. Vinnicombe, Husband & Reznek's Imaging in Oncology, 2020
Roberto García-Figueiras, Anwar Padhani, Sandra Baleato-González
The basic principle of MRE is to apply mechanical waves and evaluate the tissue's strain response to depict tissue stiffness (Figure 42.18). MRE has been tested in various tumour locations, including the breast, prostate, liver, brain, and pancreas, and may improve tumour detection and characterization (113). For example, benign breast lesions have been found to be slightly stiffer than normal tissue but significantly less stiff than malignant tumours, suggesting that MRE may improve the specificity of breast MRI (115). Additionally, preliminary studies with different therapies have demonstrated an early decrease in tumour stiffness and viscoelasticity following treatment (before changes in tumour ADC), suggesting MRE may be more sensitive than DWI to early tumour response to therapy (115). Preliminary results from Le Bihan et al. suggest that IVIM contrast can be converted quantitatively into shear modulus, providing quantitative estimates of tissue stiffness without using mechanical vibrations (116).
Biomedical Imaging Magnetic Resonance Imaging
Published in Lawrence S. Chan, William C. Tang, Engineering-Medicine, 2019
Magnetic resonance elastography (MRE) is a technique that allows characterization of tissue mechanical properties, such as shear stiffness, in response to compression or vibration (Glaser et al. 2012). To perform MRE, a driver is used to deliver mechanical waves to the tissue. These mechanical waves can be imaged as they travel through the tissue using a phase-sensitive MR pulse sequence. Image acquisition can be accomplished within a breath hold. The ability to measure tissue mechanical properties can provide valuable information for characterizing a number of diseases, such as hepatic fibrosis (Glaser et al. 2012).
Antiplatelet drugs and liver fibrosis
Published in Platelets, 2022
Pamela Czajka, Adam Przybyłkowski, Anna Nowak, Marek Postula, Marta Wolska, Dagmara Mirowska-Guzel, Anna Czlonkowska, Ceren Eyileten
It is important to note that the assessment of the hemostatic function in cirrhosis is challenging. The traditional coagulation tests like prothrombin time (PT), the international normalized ratio (INR), and activated partial thromboplastin time (aPTT) are widely used for estimating the risk of bleeding and determination of the best treatment. These tests validate only the procoagulant capacity [89]. In the injured liver production not only pro- but also anticoagulant factors are altered, and assessment of deviations of PT, aPTT, and INR may not provide a reliable prediction for bleeding risk in cirrhotic patients [90–92]. Therefore, as it was reviewed deeply by Sharma et al., to overcome the drawbacks of liver biopsy, several noninvasive techniques have been investigated for the assessment of fibrosis [85,86]. Radiologic techniques and serum-based markers are considered noninvasive methods. Radiologic techniques include ultrasound, magnetic resonance imaging and elastography (transient elastography and magnetic resonance elastography). Serum-based biomarkers of cirrhosis include ARPI, Fibrotest, FIB4 panel, NAFLD fibrosis score, Fibroindex, as well as promising markers, such as hyaluronic acid, N-terminal of serum procollagen III peptide (PIINP), TIMP-1, YKL-40 (chondrex) and ELF score [93–96].
Noninvasive imaging assessment of portal hypertension: where are we now and where does the future lie?
Published in Expert Review of Molecular Diagnostics, 2021
Shang Wan, Xijiao Liu, Hanyu Jiang, Zhongzhao Teng, Bin Song
Liver stiffness quantified by ultrasound transient elastography has been used primarily to determine liver cirrhosis. It can be used to evaluate pathological changes in the liver parenchyma due to the progression of chronic fibrosis [3]. Ultrasound transient elastography has been well-demonstrated to be associated with CSPH with satisfactory diagnostic accuracy against HVPG measurement [5]. The Baveno VI recommendation stated that transient elastography can be used as an alternative for identifying patients’ requirement of endoscopic screening if liver stiffness <20 kPa and platelet count ≥150 × 103/mm3 does not require endoscopic screening in esophageal varices patients [5]. However, the robustness of transient elastography might be affected by patients’ individual physical conditions, such as obesity and ascites. A novel parameter of spleen stiffness has been proposed recently and has shown promising capability for identifying CSPH, with a better diagnostic performance than liver stiffness [6]. However, it cannot be measured using traditional transient elastography or in patients without splenomegaly; thus, this noninvasive parameter of spleen stiffness is not recommended in general clinical applications. Magnetic resonance elastography (MRE) is another alternative method for measuring liver and spleen stiffness. It is also correlated with CSPH, with encouraging diagnostic performance [7].
Prognostic value of liver stiffness measurement in patients with hepatocellular carcinoma (HCC) treated by radiofrequency ablation: a meta-analysis
Published in International Journal of Hyperthermia, 2021
Yongchao Zhang, Hualei Chen, Shanshan Chen, Wei Li
The degree of liver fibrosis can be noninvasively evaluated by liver stiffness measurement (LSM) using magnetic resonance elastography (MRE) or ultrasound elastography, which includes the techniques of transient elastography (TE), shear wave elastography (SWE) and acoustic radio force impulse (ARFI) imaging. Several meta-analyses have demonstrated that high LSM value in patients with chronic liver diseases is associated with the increased risk of HCC and death [9]. One meta-analysis that included 1942 patients who underwent hepatic resection found that the LSM value was associated with liver-related postoperative complications, such as post-hepatectomy liver failure, hepatic insufficiency and ascites [10]. Several studies have indicated that the LSM value can predict overall survival (OS) or recurrence in patients with HCC after ablation [11–13]; however, the results of these studies have not always been consistent.