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RoFo : Fortschritte Auf Dem Gebiete Der... Jul 2024
Application of liver-specific contrast agents for evaluation of focal liver lesions - Expert recommendations from the Gastrointestinal and Abdominal Imaging Workgroup of the German Roentgen Society.
Topics: Humans; Contrast Media; Liver Neoplasms; Germany; Image Enhancement; Magnetic Resonance Imaging; Tomography, X-Ray Computed; Radiology; Liver; Societies, Medical
PubMed: 38113896
DOI: 10.1055/a-2192-9921 -
European Radiology Experimental Dec 2023To analyze regional variations in T2 and T2* relaxation times in wrist joint cartilage and the triangular fibrocartilage complex (TFCC) at 3 and 7 T and to compare...
BACKGROUND
To analyze regional variations in T2 and T2* relaxation times in wrist joint cartilage and the triangular fibrocartilage complex (TFCC) at 3 and 7 T and to compare values between field strengths.
METHODS
Twenty-five healthy controls and 25 patients with chronic wrist pain were examined at 3 and 7 T on the same day using T2- and T2*-weighted sequences. Six different regions of interest (ROIs) were evaluated for cartilage and 3 ROIs were evaluated at the TFCC based on manual segmentation. Paired t-tests were used to compare T2 and T2* values between field strengths and between different ROIs. Spearman's rank correlation was calculated to assess correlations between T2 and T2* time values at 3 and 7 T.
RESULTS
T2 and T2* time values of the cartilage differed significantly between 3 and 7 T for all ROIs (p ≤ 0.045), with one exception: at the distal lunate, no significant differences in T2 values were observed between field strengths. T2* values differed significantly between 3 and 7 T for all ROIs of the TFCC (p ≤ 0.001). Spearman's rank correlation between 3 and 7 T ranged from 0.03 to 0.62 for T2 values and from 0.01 to 0.48 for T2* values. T2 and T2* values for cartilage varied across anatomic locations in healthy controls at both 3 and 7 T.
CONCLUSION
Quantitative results of T2 and T2* mapping at the wrist differ between field strengths, with poor correlation between 3 and 7 T. Local variations in cartilage T2 and T2* values are observed in healthy individuals.
RELEVANCE STATEMENT
T2 and T2* mapping are feasible for compositional imaging of the TFCC and the cartilage at the wrist at both 3 and 7 T, but the clinical interpretation remains challenging due to differences between field strengths and variations between anatomic locations.
KEY POINTS
•Field strength and anatomic locations influence T2 and T2* values at the wrist. •T2 and T2* values have a poor correlation between 3 and 7 T. •Local reference values are needed for each anatomic location for reliable interpretation.
Topics: Humans; Wrist; Wrist Joint; Magnetic Resonance Imaging; Cartilage
PubMed: 38093075
DOI: 10.1186/s41747-023-00394-1 -
Radiology. Artificial Intelligence Nov 2023
PubMed: 38074781
DOI: 10.1148/ryai.230304 -
Nucleic Acids Research Feb 2024tRNA superwobbling, used by certain bacteria and organelles, is an intriguing decoding concept in which a single tRNA isoacceptor is used to decode all synonymous codons...
tRNA superwobbling, used by certain bacteria and organelles, is an intriguing decoding concept in which a single tRNA isoacceptor is used to decode all synonymous codons of a four-fold degenerate codon box. While Escherichia coli relies on three tRNAGly isoacceptors to decode the four glycine codons (GGN), Mycoplasma mycoides requires only a single tRNAGly. Both organisms express tRNAGly with the anticodon UCC, which are remarkably similar in sequence but different in their decoding ability. By systematically introducing mutations and altering the number and type of tRNA modifications using chemically synthesized tRNAs, we elucidated the contribution of individual nucleotides and chemical groups to decoding by the E. coli and M. mycoides tRNAGly. The tRNA sequence was identified as the key factor for superwobbling, revealing the T-arm sequence as a novel pivotal element. In addition, the presence of tRNA modifications, although not essential for providing superwobbling, was shown to delicately fine-tune and balance the decoding of synonymous codons. This emphasizes that the tRNA sequence and its modifications together form an intricate system of high complexity that is indispensable for accurate and efficient decoding.
Topics: Anticodon; Base Sequence; Codon; Escherichia coli; Glycine; RNA, Transfer; RNA, Transfer, Gly; Mycoplasma mycoides; RNA, Bacterial
PubMed: 38050960
DOI: 10.1093/nar/gkad1136 -
Archive For Rational Mechanics and... 2023We study the fine regularity properties of optimal potentials for the dual formulation of the Hellinger-Kantorovich problem (), providing sufficient conditions for the...
We study the fine regularity properties of optimal potentials for the dual formulation of the Hellinger-Kantorovich problem (), providing sufficient conditions for the solvability of the primal Monge formulation. We also establish new regularity properties for the solution of the Hamilton-Jacobi equation arising in the dual dynamic formulation of , which are sufficiently strong to construct a characteristic transport-growth flow driving the geodesic interpolation between two arbitrary positive measures. These results are applied to study relevant geometric properties of geodesics and to derive the convex behaviour of their Lebesgue density along the transport flow. Finally, exact conditions for functionals defined on the space of measures are derived that guarantee the geodesic -convexity with respect to the Hellinger-Kantorovich distance. Examples of geodesically convex functionals are provided.
PubMed: 38046049
DOI: 10.1007/s00205-023-01941-1 -
Nephrology, Dialysis, Transplantation :... May 2024Chronic kidney disease (CKD) is highly prevalent, affecting approximately 11% of US adults. Multiple studies have evaluated a potential association between CKD and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Chronic kidney disease (CKD) is highly prevalent, affecting approximately 11% of US adults. Multiple studies have evaluated a potential association between CKD and urinary tract malignancies. Summary estimates of urinary tract malignancy risk in CKD patients with and without common co-existing conditions may guide clinical practice recommendations.
METHODS
Four electronic databases were searched for original cohort studies evaluating the association between CKD and urinary tract cancers (kidney cancer and urothelial carcinoma) through 25 May 2023, in persons with at least moderate CKD and no dialysis or kidney transplantation. Quality assessment was performed for studies meeting inclusion criteria using the Newcastle-Ottawa Scale. Meta-analysis with a random-effects model was performed for unadjusted incidence rate ratios (IRR) as well as adjusted hazard ratios (aHR) for confounding conditions (diabetes, hypertension and/or tobacco use), shown to have association with kidney cancer and urothelial carcinoma. Sub-analysis was conducted for estimates associated with CKD stages separately.
RESULTS
Six cohort studies with 8 617 563 persons were included. Overall, the methodological quality of the studies was good. CKD was associated with both higher unadjusted incidence and adjusted hazard of kidney cancer (IRR 3.36, 95% confidence interval (CI) 2.32-4.88; aHR 2.04, 95% CI 1.77-2.36) and urothelial cancer (IRR 3.96, 95% CI 2.44-6.40; aHR 1.35, 95% CI 1.22-1.50) compared with persons without CKD. Examining incident urinary tract cancers by CKD severity, risks were elevated in stage 3 CKD (kidney aHR 1.89, 95% CI 1.56-2.30; urothelial carcinoma aHR 1.35, 95% CI 1.20-1.52) as well as in stages 4/5 CKD (kidney cancer aHR 2.30, 95% CI 2.00-2.66; urothelial carcinoma aHR 1.24, 95% CI 1.04-1.49).
CONCLUSIONS
Even moderate CKD is associated with elevated risk of kidney cancer and urothelial carcinoma. Providers should consider these elevated risks when managing individuals with CKD, particularly when considering evaluation for the presence and etiology of hematuria.
Topics: Humans; Renal Insufficiency, Chronic; Kidney Neoplasms; Urologic Neoplasms; Risk Factors; Incidence
PubMed: 38037426
DOI: 10.1093/ndt/gfad249 -
Orthopaedics & Traumatology, Surgery &... Apr 2024An increasing number of radiostereometry (RSA) research studies have long-term follow-up implant migration outcomes, which show ascending curves of implant migration...
BACKGROUND
An increasing number of radiostereometry (RSA) research studies have long-term follow-up implant migration outcomes, which show ascending curves of implant migration with occasionally decreasing migration. After scrutinizing images and RSA scenes related to the alternating curves, we suppose that intra-exposure patient motion may contribute to that. The main purposes of this in vitro study were 1) to identify whether the patient motion in different directions could result in the inaccurate assessment of implant migration, and 2) to figure out which direction(s) accounted for the alternating curves.
HYPOTHESIS
It was hypothesized that the assessments of implant migration would be less precise and accurate than they could be when patient motion occurred, and such motion would contribute to the alternating curves of radiostereometric implant migration.
MATERIALS AND METHODS
A customized phantom, assembled with a tibial component, was designed for simulating intra-exposure patient motion during follow-up RSA examinations. Two different Roentgen tubes were used as the current standard of radiology departments. Radiographs were acquired in a uniplanar technical arrangement. Two defined protocols were conducted: one is to simulate implant migration outcomes at post-op, the early stage (6months), and the later stage (2 to 10years) ; during the later stage, the other is to mimic patient motion by phantom motion in the medial-lateral (x), distal-proximal (y), and anterior-posterior (z) axes.
RESULTS
Phantom motion could result in the inaccurate assessment of implant migration, and translations along the medial-lateral (x) axis were the most influenced by patient motion. Motion along the medial-lateral (x) axis could account for the curves with decreasing migration.
DISCUSSION
Our assessments of implant migration may be less precise and accurate than they could be when intra-exposure patient motion occurs. We probably neglect the importance of 100% simultaneous exposures, and the influence of patient motion on RSA accuracy and data reliability, due to the difficulty in detecting patient (micro)motion. Electronically synchronized exposures of two paired Roentgen tubes are 100% simultaneous for image acquisition, and they are thus highly recommended for the assessment of implant migration in RSA.
TYPE OF STUDY AND LEVEL OF PROOF
not applicable.
Topics: Humans; Radiostereometric Analysis; Arthroplasty, Replacement, Knee; Reproducibility of Results; Knee Prosthesis; Tibia
PubMed: 38016580
DOI: 10.1016/j.otsr.2023.103776 -
Journal of Orthopaedic Research :... May 2024Meniscal tearing can increase the contact pressure between the tibia and femur by causing gapping of torn meniscus tissue. The aim of this study was to quantify gapping...
Meniscal tearing can increase the contact pressure between the tibia and femur by causing gapping of torn meniscus tissue. The aim of this study was to quantify gapping behavior of radial and longitudinal tears and their impact on peak contact pressure and mean contact area. Twelve porcine knee joints underwent unicondylar, convertible osteotomy for exact tear application and consecutive suturing. Six tantalum marker beads were positioned along meniscus tears. The joints were preloaded with sinusoidal loading cycles ranging between 0 N and 350 N. Peak load was held constant and two synchronized Roentgen stereophotogrammetric analysis x-ray images were obtained to evaluate gapping, peak contact pressure and mean contact area in the native, torn and repaired states. There was no change in gapping or peak contact pressure in longitudinal tear. By contrast, the radial tear led to a significant gapping when compared to the native state, while the inside-out suture was able to restore gapping in parts of the meniscus. An increase in contact pressure after radial tear was detected, which was again normalized after suturing. The most important finding of the study is that longitudinal tears did not gap under pure axial loading, whereas radial tears tended to separate the tear interfaces.
Topics: Animals; Swine; Menisci, Tibial; Tibial Meniscus Injuries; Biomechanical Phenomena; Knee Joint; Rupture; Meniscus
PubMed: 37986646
DOI: 10.1002/jor.25743 -
BMC Cancer Nov 2023An Organised Cervical Cancer Screening Programme (OCCSP) was started in Poland in 2006/2007. Each woman aged 25 to 59 is eligible for a free Pap test every 3 years in...
BACKGROUND
An Organised Cervical Cancer Screening Programme (OCCSP) was started in Poland in 2006/2007. Each woman aged 25 to 59 is eligible for a free Pap test every 3 years in OCCSP. Despite implementation of the OCCSP, the age-standardised cervical cancer (CC) incidence and mortality rates in 2019 were 7.3/100 000 and 3.9/100 000 respectively and were still higher than those in Western European countries with well-organised screening programmes. Apart from low coverage of the OCCSP, suboptimal performance of the screening test (conventional cytology) may be partially responsible for this situation. Several countries have already incorporated high risk Human Papillomavirus (hrHPV) testing in CC screening as a more sensitive tool reducing the risk of missing precancerous lesions and allowing for extension of screening intervals. The European Guidelines for Quality Assurance in Cervical Cancer Screening recommend pilot evaluation of a new screening test in country-specific conditions before its implementation.
METHODS
The HIPPO project (HPV testing In Polish POpulation-based cervical cancer screening program) is a randomised health services study nested in the OCCSP in Poland. The project will randomise 33 000 women aged 30-59 years to cytology or hrHPV testing (ratio: 1:1) with age stratification. In the cytology arm women with repeated Atypical Squamous Cells of Undetermined Significance (ASC-US) or ≥ Low-Grade Squamous Intraepithelial Lesions (LSIL) are referred for colposcopy. In the other arm, hrHPV ( +) women with ≥ ASC-US reflex Liquid-Based Cytology (LBC) are referred for colposcopy. Primary endpoints include detection rates of histologically confirmed high grade intraepithelial lesions or worse (CIN2 +) in each arm.
DISCUSSION
This pilot randomised healthcare study nested in the OCCSP in Poland will assess and compare the performance of hrHPV testing to current standard-cytology in order to make decisions on implementation of HPV-based screening in the country.
TRIAL REGISTRATION
This randomised healthcare service study was prospectively registered at https://clinicaltrials.gov/ (identifier: NCT04111835, protocol ID 28/2019) on 19th of September 2019.
Topics: Female; Humans; Pregnancy; Uterine Cervical Neoplasms; Uterine Cervical Dysplasia; Poland; Early Detection of Cancer; Papillomavirus Infections; Mass Screening; Atypical Squamous Cells of the Cervix; Colposcopy; Health Policy; Papillomaviridae; Vaginal Smears; Randomized Controlled Trials as Topic
PubMed: 37978452
DOI: 10.1186/s12885-023-11597-5 -
Molecular Cytogenetics Nov 2023Richter transformation (RT) is the development of aggressive lymphoma in patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). This rare...
BACKGROUND
Richter transformation (RT) is the development of aggressive lymphoma in patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). This rare disease is characterised by dismal prognosis. In recent years, there has been a deeper understanding of RT molecular pathogenesis, and disruptions of apoptosis (TP53) and proliferation (CDKN2A, MYC, NOTCH1) has been described as typical aberrations in RT.
RESULTS
A single-institution cohort of 33 RT patients were investigated by karyotyping, fluorescence in situ hybridization and single nucleotide polymorphism/copy number (CN) arrays. Most of RTs were typically manifested by diffuse large B-cell lymphoma, not otherwise specified, among the remaining cases one was classified as high-grade B-cell lymphoma with 11q aberrations. The most frequent alterations (40-60% of cases) were represented by MYC rearrangement/gain, deletions of TP53 and CDKN2A, IGH rearrangement and 13q14 deletion. Several other frequent lesions included losses of 14q24.1-q32.33, 7q31.33-q36.3, and gain of 5q35.2. Analysis of 13 CLL/SLL-RT pairs showed that RT arised from the CLL/SLL by acquiring of 10 ~ 12 cytogenetic or CN lesions/case, but without acquisition of loss of heterozygosity regions. Our result affirmed the higher genetic complexity in RT than CLL/SLL and confirmed the linear features of RT clonal evolution as predominant.
CONCLUSIONS
Cytogenomic profile was concordant with the literature data, however the role of IGH rearrangement, 14q deletion and 5q35.2 gain need to be explored. We anticipate that further characterization of RT lesions will probably facilitate better understanding of the RT clonal evolution.
PubMed: 37941034
DOI: 10.1186/s13039-023-00662-0