Assessing The Inflammatory Severity of The Terminal Ileum In Crohn Disease Using Radiomics Based On MRI

Background: Evaluating inflammatory severity using imaging is essential for Crohn’s disease (CD), but it is limited by potential interobserver variation and subjectivity. We compared the efficiency of magnetic resonance index of activity (MaRIA) collected by radiologists and a radiomics model in assessing the inflammatory severity of terminal ileum (TI).Methods: 121 patients were collected from two centers. Patients were divided into ulcerative group and mucosal remission group based on the TI Crohn's disease Endoscopic Severity Index (tCDEIS). The consistency of bowel wall thickness (BWT), relative contrast enhancement (RCE), edema, ulcer, MaRIA and features of the region of interest (ROI) between radiologists were described by weighted k coefficient and intraclass correlation coefficient (ICC), and developed receiver operating curve (ROC) of MaRIA. The radiomics model was established using reproducible features of logistic regression based on arterial staging of T1WI sequences. Delong test was used to compare radiomics with MaRIA.Results: The consistency between radiologists were moderate in BWT (ICC=0.638), fair in edema (k=0.541), RCE (ICC=0.461), MaRIA (ICC=0.579) and poor in ulcer (k=0.271). Radiomics model was developed by 6 reproducible features (ICC=0.93-0.96) and equivalent to MaRIA which evaluated by the senior radiologist(0.872 vs 0.883 in training group, 0.824 vs 0.783 in testing group, P=0.847, 0.471), both of which were significant higher than MaRIA evaluated by junior radiologist(AUC: 0.621 in training group, 0.557 in testing group, all, PB0.05).

Fractional Norms and Quasinorms Do Not Help to Overcome the Curse of Dimensionality

The curse of dimensionality causes the well-known and widely discussed problems for machine learning methods. There is a hypothesis that using the Manhattan distance and even fractional lp quasinorms (for p less than 1) can help to overcome the curse of dimensionality in classification problems. In this study, we systematically test this hypothesis. It is illustrated that fractional quasinorms have a greater relative contrast and coefficient of variation than the Euclidean norm l2, but it is shown that this difference decays with increasing space dimension. It has been demonstrated that the concentration of distances shows qualitatively the same behaviour for all tested norms and quasinorms. It is shown that a greater relative contrast does not mean a better classification quality. It was revealed that for different databases the best (worst) performance was achieved under different norms (quasinorms). A systematic comparison shows that the difference in the performance of kNN classifiers for lp at p = 0.5, 1, and 2 is statistically insignificant. Analysis of curse and blessing of dimensionality requires careful definition of data dimensionality that rarely coincides with the number of attributes. We systematically examined several intrinsic dimensions of the data.

Assessment of hepatitis and fibrosis using Gd-EOB-DTPA MRI in dogs

BackgroundGadoxetate sodium (Gd-EOB-DTPA) is taken into hepatocytes and excreted into the bile. Hepatocytes with reduced function or dysfunction due to hepatocellular carcinoma (HCC), hepatitis or hepatic fibrosis show impaired Gd-EOB-DTPA uptake. The purpose of the present retrospective case series was to assess the relationship between liver function and contrast enhancement using Gd-EOB-DTPA MRI.MethodsSixteen dogs with a histopathological diagnosis of liver disease, including six with HCC, three with nodular hyperplasia, two with hepatocellular adenoma, two with liver fibrosis and three with hepatitis were included in the study along with three dogs with suspected liver disease but no histopathological diagnosis of liver disease. Relative signal intensities (RSI) of the common bile duct and gall bladder were calculated, and their relationship with the following serum biochemical parameters was assessed: total bilirubin, alanine transaminase, alkaline phosphatase and albumin (Alb). To assess anatomical liver function, relative contrast enhancement indices (RCEI) of the liver were calculated, and differences were assessed between normal and diseased liver.ResultsRSI showed no significant differences between dogs without and with a histopathological diagnosis of liver disease (P=0.88) although they were significantly correlated with Alb (ρ=0.57, P=0.02) in dogs with a histopathological diagnosis of liver disease. RCEI was significantly higher in normal liver tissue than that in livers with hepatitis/fibrosis (P=0.048) and HCC (P=0.03) but not nodular hyperplasia/hepatocellular adenoma (P=0.51).ConclusionsGd-EOB-DTPA MRI may be potentially useful in the assessment of anatomical liver function in dogs with liver disease.

Comparing Relative Contrast in Three-dimensional Double-echo Steady State With Routine Sequences for a Better Diagnosis of Knee Cartilage Anomalies

Aims This study compared relative contrast values in three-dimensional Double Echo Steady State (DESS) sequences with two flip angles of 40 and 90 degrees and other routine sequences. The obtained data could help to prove the effects of this sequence, compared to the other routine sequences; accordingly, it could be applied for better detection of lesions resulting from cartilage abnormalities. Methods & Materials Total, 15 patients, including 9 men (14-56 y) and 6 women (36-65 y) with knee pain symptoms were referred to us by an orthopedic physician. All of the investigated patients underwent Magnetic Resonance Imaging (MRI) using DESS sequences with two flip angles of 40 and 90 degrees, as well as STIR , PD, T2, and 3D FLASH. We analyzed the acquired images using the Radiant DICOM Viewer4.6.9 software. We calculated relative contrast values for the selected SAGITAL images per sequence for each patient. The obtained data were analyzed using SPSS. Findings Friedman and Wilcoxon statistical tests data revealed significant P values (<0.05) for all the sequences examined in this study. The DESS sequence with a flip angle of 90° presented the most relative contrast value with the average score of 77.2667. The FLASH sequence provided the worst result of 3.733 for the relative contrast value. Conclusion The DESS sequence with 90° flip angle indicated the best relative contrast values and provided the best possible signal from the synovial fluid and the cartilage; therefore, it leads to the better examination of articular cartilage in terms of lesion. Accordingly, the DESS sequence with a flip angle of 90° was the optimal sequence to evaluate cartilage abnormalities among the examined sequences in this study.

Making Armenians Lebanese: The 1957 Election and the Ensuing 1958 Conflict

Chapter 4 investigates Armenians’ stance in the 1957 elections and in the ‘general’ Lebanese and the intra-Armenian mini-civil war of 1958. Armenian parties participated in, and contributed to, political tensions in Lebanon. Simultaneously, they used their position in the Lebanese political system to jostle for power within their own community – a development that turned violent and ended only in December 1958, almost two months after the Lebanese mini-civil war had ended. This tension and violent confrontation between Armenian parties and their armed men had a crucial spatial effect: it unprecedentedly territorialized certain neighborhoods of Beirut. Whereas parts of Lebanon were organized by sects and classes, by relative contrast, it was according to political party affiliation that in 1957/1958 many Armenians of Mar Mikael, Sin el Fil, Bourj Hamoud, and Corniche el-Nahr were re-sorted and relocated, often by force. Lebanese Armenians aligned along the right-left fault lines that divided Lebanese politics and society— more than other confessions, indeed. Vice versa, the Lebanese state was Armenianized, as it were, in that it started to pay more attention to Armenian matters than before, intervening directly and by military force in Armenian neighborhoods in order to finally end the internecine Armenian confrontation.

Scleral pigmentation leads to conspicuous, not cryptic, eye morphology in chimpanzees

Gaze following has been argued to be uniquely human, facilitated by our depigmented, white sclera [M. Tomasello, B. Hare, H. Lehmann, J. Call, J. Hum. Evol. 52, 314–320 (2007)]—the pale area around the colored iris—and to underpin human-specific behaviors such as language. Today, we know that great apes show diverse patterns of scleral coloration [J. A. Mayhew, J. C. Gómez, Am. J. Primatol. 77, 869–877 (2015); J. O. Perea García, T. Grenzner, G. Hešková, P. Mitkidis, Commun. Integr. Biol. 10, e1264545 (2016)]. We compare scleral coloration and its relative contrast with the iris in bonobos, chimpanzees, and humans. Like humans, bonobos’ sclerae are lighter relative to the color of their irises; chimpanzee sclerae are darker than their irises. The relative contrast between the sclera and iris in all 3 species is comparable, suggesting a perceptual mechanism to explain recent evidence that nonhuman great apes also rely on gaze as a social cue.

Dynamic Phantom for Flow Model in Magnetic Resonance Angiography

Purpose. To develop phantom for flow modeling in magnetic resonance angiography (MRA): relative contrast assessment, accuracy of the linear velocity and volumetric flow, what improve accuracy of diagnostic in cardiac and neurosurgical clinics (quality assessment of blood and cerebrospinal fluid motion). To compare scanners of different manufactures in points of the MRA efficiency using the developed phantom.Materials and methods. The main part of dynamic phantom consists of a disc filled with agarose gel (for linear and volumetric velocity control) and silicone tubes for fluid flow modelling. MR study was performed at MRI units of two manufactures for comparing quantitative assessments of MRA sequences: 2DTOF, 3DTOF, and at three MRI units of one firm for estimated accuracy calibration curve calculating and linear velocity and volumetric flow determination for PC MRA. Phantom study well correlate with clinical MRA results.Results. Obtained phantom scanning results in 2DTOF, 3DTOF sequences allow for objective comparing two MRI units of different manufactures. For 2DTOF mode was showed more effective signal enhancement affected by TOF effect for scanner of manufacture 2, then manufacture 1: 8.86 ± 0.88 и 6.07 ± 0.03 corresponding. For 3DTOF was observed rather more inflow relative contrast affected by TOF effect for scanner of manufacture 1: 6.06 ± 0.47 and 3.17 ± 0.83 corresponding. However, for manufacture 1 was showed more significant signal suppression for fat tissue, which improve vasculature visualization. Accuracy linear velocity fluid flow measurement in 2DPC is equal to ±2σ = ±0,4 by five pixels for three scanners of one manufacture. Using developed phantom was modelled MRA effects in 3DPC and Time-SLIP modes.Conclusions. The developed dynamic phantom can be used for calibration tests in MRA. The case of MRI units of two manufactures were compared quantitative assessments of MRA sequences and analyzed methods of enhancement fluid flow signal.