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Background: To develop and validate a nomogram model based on Gd-EOB-DTPA enhanced MRI for differentiation between hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH) showing iso- or hyperintensity in the hepatobiliary phase (HBP)., Methods: A total of 75 patients with 49 HCCs and 26 FNHs randomly divided into a training cohort (n = 52: 34 HCC; 18 FNH) and an internal validation cohort (n = 23: 15 HCC; 8 FNH). A total of 37 patients (n = 37: 25 HCC; 12 FNH) acted as an external test cohort. The clinical and imaging characteristics between HCC and FNH groups in the training cohort were compared. The statistically significant parameters were included into the FAE software, and a multivariate logistic regression classifier was used to identify independent predictors and establish a nomogram model. Receiver operating characteristic (ROC) curves were used to evaluate the prediction ability of the model, while the calibration and decision curves were used for model validation. Subanalysis was used to compare qualitative and quantitative characteristics of patients with chronic hepatitis and cirrhosis between the HCC and FNH groups., Results: In the training cohort, gender, age, enhancement rate in the arterial phase (AP), focal defects in uptake were significant predictors for HCC showing iso- or hyperintensity in the HBP. In the training cohort, area under the curve (AUC), sensitivity and specificity of the nomogram model were 0.989(95%CI: 0.967-1.000), 97.1% and 94.4%. In the internal validation cohort, the above three indicators were 0.917(95%CI: 0.782-1.000), 93.3% and 87.5%. In the external test cohort, the above three indicators were 0.960(95%CI: 0.905-1.000), 84.0% and 100.0%. The results of subanalysis showed that age was the independent predictor in the patients with chronic hepatitis and cirrhosis between HCC and FNH groups., Conclusions: Gd-EOB-DTPA enhanced MRI nomogram model may be useful for discriminating HCC and FNH showing iso- or hyperintensity in the HBP before surgery., (© 2024. The Author(s).)

Purpose: Biomechanical properties can be used as biomarkers to diagnose tumors, monitor tumor development, and evaluate treatment efficacy. The purpose of this preliminary study is to characterize the biomechanical environment of two typical liver tumors, hemangiomas (HEMs) and hepatocellular carcinomas (HCCs), and to investigate the potential of using strain metrics as biomarkers for tumor diagnosis, based on a limited clinical dataset., Methods: Magnetic resonance (MR) tagging was used to quantify the motion and deformation of the two types of liver tumors. Displacements of the tumors arising from a heartbeat were measured over one cardiac cycle. Local biomechanical conditions of the tumors were characterized by estimating two principal strains (ε 1 and ε 2 ) and an octahedral shear strain (ε soct ) of the tumor and its peripheral region. Biomechanical conditions of the tumors were compared with those of the arbitrarily selected regions from healthy volunteers., Results: We observed that the HCCs had significantly smaller strain values compared to their peripheral tissues. However, the HEMs did not have significantly different strains from those of the peripheral tissues, and were similar to healthy liver regions. The sensitivity of using ε 1 , ε 2 , and ε soct to diagnose HCC were all 1, while the sensitivity of using ε 1 , ε 2 , and ε soct to diagnose HEM were 0.67, 0.17, and 0.67, respectively., Conclusions: Lagrangian strain metrics provide insight into the biomechanical conditions of certain liver tumors in the human body and may provide another perspective for tumor characterization and diagnosis., (© 2019 American Association of Physicists in Medicine.)

An electromagnetic actuator was designed for magnetic resonance elastography (MRE). The actuator is unique in that it is simple, portable, and capable of brain, abdomen, and phantom imagings. A custom-built control unit was used for controlling the vibration frequency and synchronizing the trigger signals. An actuation unit was built and mounted on the specifically designed clamp and holders for different imaging applications. MRE experiments with respect to gel phantoms, brain, and liver showed that the actuator could produce stable and consistent mechanical waves. Estimated shear modulus using local frequency estimate method demonstrated that the measurement results were in line with that from MRE studies using different actuation systems. The relatively easy setup procedure and simple design indicated that the actuator system had the potential to be applied in many different clinical studies., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: To describe the MRI findings in ten patients of spinal epidural angiolipoma for differentiated diagnosis presurgery., Materials and Methods: Ten surgically proved cases of spinal epidural angiolipomas were retrospectively reviewed, and the lesion was classified according to the MR findings., Results: Ten tumors were located in the superior (n = 4), middle (n = 2), or inferior (n = 4) thoracic level. The mass, with the spindle shape, was located in the posterior epidural space and extended parallel to the long axis of the spine. All lesions contained a fat and vascular element. The vascular content, correlating with the presence of hypointense regions on T1-weighted imaging (T1WI) and hyperintense signals on T2-weighted imaging, had marked enhancement. However, there were no flow void signs on MR images. All tumors were divided into two types based on the MR features. In type 1 (n = 3), the mass was predominantly composed of lipomatous tissue (> 50%) and contained only a few small angiomatous regions, which had a trabeculated or mottled appear. In type 2 (n = 7), the mass, however, was predominantly composed of vascular components (> 50%), which presented as large foci in the center of the mass., Conclusion: Most spinal epidural angiolipomas exhibit hyperintensity on T1WI while the hypointense region on the noncontrast T1WI indicates to be vascular, which manifests an obvious enhancement with gadolinium administration.

Purpose To assess the ability of diffusion-weighted imaging (DWI) for evaluating T stage and correlation with histological T stage of rectal cancer. Method The diagnostic accuracy, sensitivity, and specificity of T 2 WI and DWI combined with T 2 WI for T stage were evaluated. Mean tumor apparent diffusion coefficient (ADC) was compared with histological T stage. Result There were no significant differences in the diagnostic accuracy, sensitivity, and specificity no matter what kind of T stage was concerned. The difference between ADC values and histological T stage were significantly different. Conclusion DWI was useful for evaluating T stage of rectal cancer. The ADC may predict the histological grade. [ABSTRACT FROM AUTHOR]