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Background: While MR enterography allows detection of inflammatory bowel disease (IBD), the findings continue to be of limited use in guiding treatment--medication vs. surgery. Purpose: To test the feasibility of MR elastography of the gut in healthy volunteers and IBD patients. Study Type: Prospective pilot. Population: Forty subjects (healthy volunteers: n = 20, 37 ± 14 years, 10 women; IBD patients: n = 20 (ulcerative colitis n = 9, Crohn's disease n = 11), 41 ± 15 years, 11 women). Field Strength/Sequence: Multifrequency MR elastography using a single-shot spin-echo echo planar imaging sequence at 1.5 T with drive frequencies of 40, 50, 60, and 70 Hz. Assessment: Maps of shear-wave speed (SWS, in m/s) and loss angle (f, in rad), representing stiffness and solid-fluid behavior, respectively, were generated using tomoelastography data processing. Histopathological analysis of surgical specimens was used as reference standard in patients. Statistical Tests: Unpaired t-test, one-way analysis of variance followed by Tukey post hoc analysis, Pearson's correlation coefficient and area under the receiver operating characteristic curve (AUC) with 95%-confidence interval (CI). Significance level of 5%. Results: MR elastography was feasible in all 40 subjects (100% technical success rate). SWS and f were significantly increased in IBD by 21% and 20% (IBD: 1.45 ± 0.14 m/s and 0.78 ± 0.12 rad; healthy volunteers: 1.20 ± 0.14 m/s and 0.65 ± 0.06 rad), whereas no significant differences were found between ulcerative colitis and Crohn's disease (P = 0.74 and 0.90, respectively). In a preliminary assessment, a high diagnostic accuracy in detecting IBD was suggested by an AUC of 0.90 (CI: 0.81-0.96) for SWS and 0.84 (CI: 0.71-0.95) for f. Data Conclusion: In this pilot study, our results demonstrated the feasibility of MR elastography of the gut and showed an excellent diagnostic performance in predicting IBD. [ABSTRACT FROM AUTHOR]

Accurate radiological differentiation of parotid tumors remains challenging despite recent technical advances in quantitative medical imaging. Multifrequency magnetic resonance elastography (MRE) could provide additional information on viscoelastic properties of normal and abnormal biological tissues. This study investigates the feasibility of MRE of the parotid glands in healthy participants and provides first reference values. 20 healthy participants underwent multifrequency MRE of both parotid glands at 3 Tesla. Shear waves at frequencies of 25, 30, 40, and 50 Hz were introduced into the participants' heads through the occiput using pressurized-air actuators. Shear wave speed (SWS) and loss angle of the shear modulus (φ) were reconstructed by tomoelastography post-processing as surrogate parameters for tissue stiffness and viscosity or fluidity. 10 participants underwent repeated MRE to determine test–retest reliability based on intraclass correlation coefficients. All MRE datasets acquired could be included in the analysis. Mean SWS was 0.97 ± 0.13 m/s, and mean φ was 0.59 ± 0.05 rad, each for both sides combined and without notable lateral difference (p = 0.88/0.87). Test–retest reliability was good for SWS (ICC = 0.84 for both sides/ICC = 0.77 for the right side/ICC = 0.79 for the left side) and good to excellent for φ(ICC = 0.94/0.86/0.90). Multifrequency MRE of the parotid glands is feasible and reliable. This technique, therefore, is a promising method for investigating the viscoelastic properties of salivary gland tumors in future studies. [ABSTRACT FROM AUTHOR]

Purpose: Despite its success in the assessment of prostate cancer (PCa), in vivo multiparametric MRI has limitations such as interobserver variability and low specificity. Several MRI methods, among them MR elastography, are currently being discussed as candidates for supplementing conventional multiparametric MRI. This study aims to investigate the detection of PCa in fresh ex vivo human prostatectomy specimens using MR elastography. Methods: Fourteen fresh prostate specimens from men with clinically significant PCa without formalin fixation or prior radiation therapy were examined by MR elastography at 500 Hz immediately after radical prostatectomy in a 9.4T preclinical scanner. Specimens were divided into 12 segments for both calculation of storage modulus (G′ in kilopascals) and pathology (Gleason score) as reference standard. Sensitivity, specificity, and area under the receiver operating characteristic curve were calculated to assess PCa detection. Results: The mean G′ and SD were as follows: all segments, 8.74 ± 5.26 kPa; healthy segments, 5.44 ± 4.40 kPa; and cancerous segments, 10.84 ± 4.65 kPa. The difference between healthy and cancerous segments was significant with P ≤.001. Diagnostic performance assessed with the Youden index was as follows: sensitivity, 69%; specificity, 79%; area under the curve, 0.81; and cutoff, 10.67 kPa. Conclusion: Our results suggest that prostate MR elastography has the potential to improve diagnostic performance of multiparametric MRI, especially regarding its 2 major limitations: interobserver variability and low specificity. Particularly the high value for specificity in PCa detection is a stimulating result and encourages further investigation of this method. [ABSTRACT FROM AUTHOR]

γ-TiAl and α2-Ti3Al intermetallic matrix composites (IMC) with TiC reinforcement was laser alloyed on a Ti-6AI-4V substrate. Two different starting powder mixtures based on Al-VC and Al-Cr3C2 was used to improve the toughness and ductility of the matrix. In one of the powder mixtures, AI-VC, the laser process parameters were varied to produce γ-TiAl /α2-Ti3Al and α2-Ti3Al matrix in the surface of Ti-6AI-4V. The coatings were characterised by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and energy-dispersive spectroscopy (EDS). The cross-sectional microhardness of the tested specimens was measured before and after cavitation to identify any work hardening. In a vibratory cavitation erosion test the alloyed layer, which contains predominantly α2-Ti3Al in the matrix showed an improved erosion resistance by a factor of up to 5.2. Preferential removal of more brittle y-TiAl in the multi-phase γ-TiAl/α2→Ti3Al IMC coating is believed to have a destructive influence on the coating performance. Over the range of process parameters investigated, an improvement in hardness favours a high erosion resistance. All alloyed layers failed by brittle fracture with varying severity. [ABSTRACT FROM AUTHOR]

Background: While standard clinical magnetic resonance (MR) enterography can detect inflammatory bowel disease, it is of limited value in deciding between medical versus surgical treatment. Alternatively, intestinal MR elastography has the potential to contribute additional information to therapeutic decision-making; however, the influence of bowel distension by oral contrast agent on viscoelastic tissue properties remains elusive. Therefore, we aimed to investigate the influence of oral contrast agent-induced bowel distension on the viscoelastic properties of the terminal ileum in healthy volunteers., Methods: In this prospective pilot study, 20 healthy volunteers (33.2±8.2 years; 10 men, 10 women) underwent multifrequency MR elastography using a single-shot spin-echo echo planar imaging sequence at 1.5 Tesla and drive frequencies of 40, 50, 60 and 70 Hz. Maps of shear wave speed ( c in ms -1 ) and loss angle ( φ in rad), representing stiffness and viscous properties, respectively, were generated using tomoelastography data processing. The volunteers were scanned before and after ingestion of 1,000 mL of 2% mannitol solution as oral contrast agent., Results: There was no significant difference in terminal ileum biomechanical properties before vs. after ingestion of an oral contrast agent (mean c : 1.47±0.24 vs. 1.40±0.25 ms -1 with P=0.37; mean φ : 0.70±0.12 rad vs. 0.68±0.12 rad with P=0.61). Moreover, there was no statistically significant correlation between MR elastography parameters before and after the ingestion of oral contrast ( c : r =0.22, P=0.36; φ : r =0.24, P=0.30)., Conclusions: The results of this study suggest that bowel distension for intestinal MR elastography has no systematic effect on the biomechanical tissue properties of the terminal ileum determined by MR elastography. Therefore, future study protocols appear feasible with or without oral contrast agents., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-24-101/coif). B.S., A.A.K., B.H., J.B., I.S., and R.R. report that this study was funded by the German Research Foundation. B.H. is Grant recipient from Abbott, AbbVie, Ablative Solutions, Accovion, Achogen Inc., Actelion Pharmaceuticals, ADIR, Aesculap, Agios Pharmaceuticals, INC., AGO, Arbeitsgemeinschaft industrieller Forschungsvereinigungen, Arbeitsgemeinschaft internistische Onkologie, Aktionsbündnis Partnersicherheit e.V., Alexion Pharmaceuticals, Amgen, AO Foundation, Aravive, Arena Pharmaceuticals, ARMO Biosciences, Inc., Array Biopharma Inc., Art photonics GmbH Berlin, ASAS, Ascelia Pharma AB, Ascendis, Advanced sleep research, Astrellas, AstraZeneca, August Research OOF, Sofia, BG, BARD, Basiliea, Bayer Healthcare, Bayer Schering Pharma, Bayer Vital, BBraun, BerGenBioASA, Berlin-Brandenburger Centrum für regenerative Therapie, Berliner Krebsgesellschaft, Biontech Mainz, BioNTech SE, Biotronik, Bioven, BMBF, BMS, Boehring Ingelheimer, Boston Biomedical Inc., Boston Scientific Medizintechnik GmbH, BRACCO Group, Brahms GmbH, Brainsgate, Bistol-Myers Squibb, Calithera Biosciences UK, Cantargia AB, Medicon Village, Cascadian Therapeutics, Inc., Celgene, CELLACT Pharma, Celldex Therapeutics, Cellestia Biotech AG CH, CeloNova BioSciences, and Charité research organization GmbH. B.S. has served as consultant for Abbvie, Abivax, BMS, Boehringer, CED Service GmbH, Endpoint Health, Falk, Galapagos, Janssen, Lilly, Pfizer, Takeda, and Predictimmune; he received speaker fees from: AbbVie, BMS, CED Service GmbH, Falk, Ferring, Galapagos, Janssen, Lilly, Materia Prima, Takeda, Pfizer and grant support by Arena/Pfizer (served as representative of the Charité). The other authors have no conflicts of interest to declare., (2024 Quantitative Imaging in Medicine and Surgery. All rights reserved.)