Purpose
In normal eyes, a fixed relationship between anterior and posterior corneal astigmatism is assumed, especially for lens power calculations. This study assessed the association between ...anterior and posterior corneal astigmatism and thickness.
Methods
Normal corneas were examined by slit‐lamp microscopy and Scheimpflug imaging. The differences between vertical and horizontal thicknesses at 4‐mm and 6‐mm‐diameters were calculated. Anterior and posterior astigmatism were calculated as the difference between steep and flat powers based on the corresponding radii of curvature and refractive indices. Comparisons and significances of correlations were assessed by using generalized estimating equation models.
Results
Fifty‐four subjects (101 corneas) aged 18–80 years were included. Peripheral corneas were thicker vertically than horizontally (p < 0.001) at 4 mm by 13.4 ± 9.4 µm (mean ± standard deviation) and at 6 mm by 8.6 ± 4.8 µm. Anterior corneal astigmatism was 1.08 ± 0.57 D and was aligned vertically (73%), horizontally (6%), or obliquely (21%). Posterior corneal astigmatism was −0.31 ± 0.13 D and was aligned vertically (94%) or obliquely (6%). Anterior and posterior astigmatism were correlated in eyes with vertical anterior astigmatism (r = 0.65; p < 0.001), but not in eyes with oblique or horizontal anterior astigmatism. The difference between vertical and horizontal corneal thickness correlated with posterior astigmatism at 4 mm (r = −0.58; p < 0.001) and at 6 mm (r = −0.61; p < 0.001).
Conclusions
The posterior cornea is normally ellipsoid in shape with a steep vertical meridian that corresponds to the cornea being thicker in the vertical paracentral region. Understanding the normal relationship between anterior and posterior corneal surfaces is important when assessing the same in corneal diseases.
Central to the One Health approach and any disease eradication program is the question of whether a pathogen has a non-human reservoir. Despite well-established conceptual frameworks that define a ...reservoir of infection, empirical characterization of reservoirs often remains controversial, challenging and sometimes misleading. What is essentially missing are applicable requirements that standardize the use of the term 'reservoir of infection' across multiple disciplines. We propose an empirical framework, considering maintenance and feasible transmission of a pathogen, to standardize the acceptance of a disease reservoir across multiple disciplines. We demonstrate the intended use of these requirements by applying them to different diseases that are known to infect both humans and animals.
In our most recent study, we found that in Tanzania infection with Treponema pallidum (TP) subsp. pertenue (TPE) is present in four different monkey species. In order to gain information on the ...diversity and epidemiological spread of the infection in Tanzanian nonhuman primates (NHP), we identified two suitable candidate genes for multi-locus sequence typing (MLST). We demonstrate the functionality of the MLST system in invasively and non-invasively collected samples. While we were not able to demonstrate frequent interspecies transmission of TPE in Tanzanian monkeys, our results show a clustering of TPE strains according to geography and not host species, which is suggestive for rare transmission events between different NHP species. In addition to the geographic stability, we describe the relative temporal stability of the strains infecting NHPs and identified multi-strain infection. Differences between TPE strains of NHP and human origin are highlighted. Our results show that antibiotic resistance does not occur in Tanzanian TPE strains of NHP origin.
The first yaws eradication campaign reduced the prevalence of yaws by 95%. In recent years, however, yaws has reemerged and is currently subject to a second, ongoing eradication campaign. Yet, the ...epidemiological status of Tanzania and 75 other countries with a known history of human yaws is currently unknown. Contrary to the situation in humans in Tanzania, recent infection of nonhuman primates (NHPs) with the yaws bacterium Treponema pallidum subsp. pertenue (TPE) have been reported. In this study, we consider a One Health approach to investigate yaws and describe skin ulcers and corresponding T. pallidum serology results among children living in the Tarangire-Manyara ecosystem, an area with increasing wildlife-human interaction in northern Tanzania. To investigate human yaws in Tanzania, we conducted a cross-sectional study to screen and interview skin-ulcerated children aged 6 to 15 years, who live in close proximity to two national parks with high numbers of naturally TPE-infected monkeys. Serum samples from children with skin ulcers were tested for antibodies against the bacterium using a treponemal (Treponema pallidum Particle Agglutination assay) and a non-treponemal (Rapid Plasma Reagin) test. A total of 186 children aged between 6 and 15 years (boys: 10.7 + or - 2.1 (mean + or - SD), N = 132; girls: 10.9 + or - 2.0 (mean + or - SD), N = 54) were enrolled. Seven children were sampled at health care facilities and 179 at primary schools. 38 children (20.4%) reported active participation in bushmeat hunting and consumption and 26 (13.9%) reported at least one physical contact with a NHP. None of the lesions seen were pathognomonic for yaws. Two children tested positive for treponemal antibodies (1.2%) in the treponemal test, but remained negative in the non-treponemal test. We found no serological evidence of yaws among children in the Tarangire-Manyara ecosystem. Nevertheless, the close genetic relationship of human and NHPs infecting TPE strains should lead to contact prevention with infected NHPs. Further research investigations are warranted to study the causes and possible prevention measures of spontaneous chronic ulcers among children in rural Tanzania and to certify that the country is free from human yaws.
Background
To assess the feasibility and safety of a gelfoam torpedo plugging technique for embolization of the transsplenic access channel in adult patients following transvenous portal vein ...interventions.
Materials and methods
Between 09/2016 and 08/2021, an ultrasound guided transsplenic portalvenous access (TSPVA) was established in twenty-four adult patients with a 21-G needle and 4-F microsheath under ultrasound guidance. Afterwards, sheaths ranging from 4-F to 8-F were inserted as needed for the procedure. Following portal vein intervention, the splenic access tract was embolized with a gelfoam-based tract plugging (GFTP) technique. TSPVA and GFTP were performed twice in two patients. Patients’ pre-interventional and procedural characteristics were analyzed to assess the feasibility and safety of the plugging technique according Cardiovascular and Interventional Radiological Society of Europe (CIRSE) classification system. Values are given as median (minimum;maximum). Subgroup analysis of intercostal vs. subcostal puncture site for TSPVA was performed using the two-sided Mann–Whitney-U test or Student’s t-test and Fisher’s exact test. Level of significance was
p
< 0.05.
Results
The study population’s age was 56 (29;71) years and 54% were female patients. Primary liver disease was predominantly liver cirrhosis with 62% of the patients. Pre-interventional model for end-stage liver disease score was 9 (6;25), international normalized ratio was 1.15 (0.86;1.51), activated partial thromboplastin time was 33s (26s;52s) and platelet count was 88.000/µL (31.000;273.000/µL). Ascites was present in 76% of the cases. Craniocaudal spleen diameter was 17cm (10cm;25cm). Indication for TSPVA was assisted transjugular intrahepatic portosystemic shunt placement in 16 cases and revision in two cases, portal vein stent placement in five cases and variceal embolization in three cases. TSPVA was successfully established in all interventions; interventional success rate was 85% (22/26). The splenic access time was 33min (10min;133min) and the total procedure time was 208min (110min;429min). Splenic access was performed with a subcostal route in 11 interventions and with an intercostal route in 15 interventions. Final sheath size was 4-F in 17 cases, 5-F in three cases, 6-F in five cases, 7-F in two cases and 8-F in one case. A median of two gelfoam cubes was used for GFTP. TSPVA- and GFTP-related complications occurred in 4 of 26 interventions (15%) with a subcapsular hematoma of the spleen in two patients (CIRSE grade 1), access-related infection in one patient (CIRSE grade 3) and both in one patient (CIRSE grade 3). In detail, one access-related complication occurred in a patient with subcostal TSPVA (CIRSE grade 1 complication) and the other three complications occurred in patients with intercostal TSPVA (one CIRSE grade 1 complication and two CIRSE grade 3 complication) (
p
= 0.614). No patient required interventional or surgical treatment due to puncture tract bleeding.
Conclusion
Gelfoam-based plugging of the puncture tract was feasible and safe for transsplenic access in adult patients undergoing percutaneous portal vein interventions. The lack of major bleeding complications and complete absorption of the gelatine sponge make it a safe alternative to transjugular and transhepatic access and re-interventions via the splenic route.
Along with ultrasound, computed tomography (CT) is one of the imaging modalities of choice in patients with suspected diverticular disease (DD). Recently, a newer Classification of Diverticular ...Disease (CDD) has been proposed. However, its reliability in daily radiological practice has never been proven. Therefore, our aim was to evaluate the intra- and interobserver agreement of the CDD in abdominal CT scans.
In this retrospective study, 481 CT scans of patients with suspected DD were included. Two readers (one board-certified radiologist with 6 years of experience, one 3 rd year radiology resident) individually evaluated all CTs in two reading sessions using the CDD. A composite endpoint of a prior consensus reading, follow-up, and intraoperative findings served as the reference. Intra- and interobserver agreement were calculated using Cohen-k statistic.
DD was present in 317 cases (66 %), mostly classified as CDD stage 0, 1b, and 2a (28 %, 30 %, und 14 %). Intraobserver agreement was almost perfect for both readers (kappa 0.93 and 0.88). Interobserver agreement was high and improved from substantial (kappa 0.77) in the first reading session to almost perfect (kappa 0.84) in the second reading session. The interobserver agreement was best for CDD types 0 (diverticulosis) and 2c (free perforated diverticulitis) (mean kappa 0.83 and 0.86) and poorest for CDD types 1a (diverticulitis without phlegmon) and 2b (covered diverticulitis with macroabscess) (mean kappa 0.17 and 0.38). Intra- and interobserver agreement of acute uncomplicated (CDD type 1) and acute complicated diverticulitis (CDD type 2) were substantial to almost perfect (mean kappa 0.63-0.86). Agreement with the reference was almost perfect for both observers (mean kappa 0.86 and 0.82). Administration of rectal contrast did not significantly improve the diagnosis.
The CDD is a classification based on relatively clear imaging characteristics, which can be readily applied by radiologists with different expertise. In our study, the CDD had a high intra- and interobserver agreement, enabling a reliable therapy-related categorization of DD.
· The Classification of Diverticular Disease (CDD) is an easy-to-use classification for diverticular disease based on relatively clear image features.. · The CDD can be applied equally by radiologists with different levels of experience in the clinical routine.. · The high intra- and interobserver agreement indicates high reliability in the therapy-relevant classification of diverticulitis on CT..
· Schmidbauer M, Levers A, Wacker FK et al. Classification of Diverticular Disease (CDD) - assessment of the intra- and interobserver agreement in abdominal CT scans. Fortschr Röntgenstr 2024; 196: 591 - 599.
To compare the depiction of pulmonary arteries in pulmonary arterial catheter-based contrast-enhanced cone-beam CT with peripheral intravenous contrast-enhanced multidetector CT in patients with ...suspected chronic thromboembolic pulmonary hypertension.
In 20 patients (15 men and 5 women, 63.4 y ± 16.3), cone-beam CT using a catheter placed in the main pulmonary artery and 64-row multidetector CT using an appropriate venous access were performed. Contrast enhancement was measured in the main pulmonary artery, the right and left pulmonary arteries, and the left atrium. The amount of peripheral vessel conspicuity adjacent to the pleural surface (distance from vessel-to pleura) was measured. Two readers (R1, R2) independently evaluated the pulmonary arteries for image quality and pathologic findings in both modalities.
Contrast density was higher in the main pulmonary artery and right and left pulmonary arteries (P < .002) and lower in the left atrium (P = .001) on cone-beam CT. The smallest distance between clearly delineated vessels and the pleura was significantly lower on cone-beam CT images (P < .0001). Interobserver agreement was good for cone-beam CT (κ = 0.79) and multidetector CT (κ = 0.78), whereas intermodality agreement was moderate (R1, κ = 0.60; R2, κ = 0.59). Both readers detected more weblike stenoses with cone-beam CT (76; 22%) compared with multidetector CT (25; 7%).
Cone-beam CT shows improved contrast between pulmonary arteries and the left atrium and allows a more detailed depiction of the pulmonary arteries.
The genus
Treponema
contains a number of human and animal pathogenic as well as symbiotic bacteria that are found in vastly different anatomical and environmental habitats. Our understanding of the ...species range, evolution, and biology of these important bacteria is still limited. To explore the diversity of treponemes, we established, validated, and tested a novel metataxonomic approach. As the informative nature of the hypervariable regions of the 16S rRNA gene differ, we first analyzed each variable region independently. Considering the
in silico
results obtained, we established and validated the sequencing of the V4-region of the 16S rRNA gene using known mixtures of
Treponema
species as well as a selected number of clinical samples. The metataxonomic approach was able to identify
Treponema
to a near-species level. We demonstrate that using a spirochete-specific enrichment, our method is applicable to complex microbial communities and large variety of biological samples. The metataxonomic approach described provides a useful method to unravel the full diversity and range of
Treponema
in various ecosystems.
Background
The aim of this animal study was to compare the fluoroscopic image quality (IQ) and radiation dose between a tantalum (Ta)-specific contrast-to-noise ratio-driven exposure control (Ta-CEC) ...and a detector dose-driven exposure control (DEC) in abdominal angiography.
Methods
Nine angiography scenarios were created in seven anaesthetised pigs using Ta-based embolisation material during percutaneous liver and kidney intervention. Fluoroscopic images were acquired using three DEC protocols with different dose levels and Ta-CEC protocols with different IQ levels, sampled in small steps. Polymethyl-methacrylate and aluminium plates were used to simulate attenuation of three water equivalent thicknesses (WET). Three blinded readers evaluated the IQ of DEC and dose equivalent Ta images and selected the Ta-IQ equivalent image corresponding to the DEC image.
Results
Interobserver agreement for the IQ assessment was 0.43 for DEC, 0.56 for Ta-CEC and for the assessment of incident air kerma at the interventional reference point (
K
a,r
) for the Ta-IQ equivalent image 0.73. The average IQ of the dose equivalent Ta images was superior compared to the DEC images (
p
< 0.001) and also for every WET (26, 31, or 36 cm) and dose level (
p
≤ 0.022). The average
K
a,r
for the Ta-IQ equivalent images was 59 ± 16% (mean ± standard deviation) lower compared to the DEC images (
p
< 0.001).
Conclusions
Compared to DEC, Ta-CEC significantly improved the fluoroscopic depiction of Ta, while maintaining the
K
a,r
. Alternatively, the
K
a,r
can be significantly reduced by using Ta-CEC instead of DEC, while maintaining equivalent IQ.
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