Pseudoaneurysm - A Late and Rare Occurrence Following Shoulder Arthroscopy

Introduction

The incidence of vascular injuries from arthroscopic surgeries has been reported to be 0.005%. Pseudoaneurysms account for 11% of those injuries.

Case Report

In this case report, we discuss a 76-year-old female who presented with a pulsatile swelling in the right shoulder after 10 years following arthroscopic rotator cuff repair. Imaging confirmed the diagnosis of a posterior circumflex artery pseudoaneurysm. The patient was successfully embolised using a transradial approach with thrombosis of the pseudoaneurysm.

Conclusion

Vascular injuries following arthroscopic shoulder surgery are rare. However, a pseudoaneurysm should be considered in patients who present with swelling at the surgical site, regardless of the post-operative interval.

Sudden perceived absence of foetal movement - a unique presentation of a vertebral haemangioma in pregnancy

OBJECTIVE

Symptomatic vertebral haemangiomas that present during pregnancy are extremely uncommon with few cases reported in literature. Epidural haemangiomas are rarer still with few documented.

METHODS

In this report, we describe the case of a 22-year-old pregnant patient who presented with apparent loss of foetal movement at 38 weeks' gestation. Clinical review demonstrated the foetus was well but neurological examination revealed lower limb paresthesia, paresis and evident uterine hypoesthesia. An MRI scan illustrated a haemangioma in the T1 vertebral body with an epidural component causing cord compression.

RESULTS

The management of spinal haemangiomas that present during pregnancy is a complex clinical scenario, which requires careful multidisciplinary consideration to determine if surgical intervention is appropriate. In this case, the patient had an emergency caesarean section followed by posterior decompression and laminectomy of the T1 vertebra with excellent post-operative recovery.

CONCLUSION

Gestational increase in the size of vertebral haemangiomas is well documented. We discuss a rare case in which a young pregnant patient presents with an atypical symptom of a vertebral haemangioma (uterine hypoesthesia). This case highlights the importance of prompt imaging in these scenarios and a cohesive multidisciplinary approach in order to provide optimal treatment for the patient.

Hydrogen isotopic analysis of nuclear reactor materials using ultrafast laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy is a promising method for rapidly measuring hydrogen and its isotopes, critical to a wide range of disciplines (e.g. nuclear energy, hydrogen storage). However, line broadening can hinder the ability to detect finely spaced isotopic shifts. Here, the effects of varying plasma generation conditions (nanosecond versus femtosecond laser ablation) and ambient environments (argon versus helium gas) on spectral features generated from Zircaloy-4 targets with varying hydrogen isotopic compositions were studied. Time-resolved 2D spectral imaging was employed to detail the spatial distribution of species throughout plasma evolution. Results highlight that hydrogen and deuterium isotopic shifts can be measured with minimal spectral broadening in a ∼ 10 Torr helium gas environment using ultrafast laser-produced plasmas.

Correlating work hardening with co-activation of stacking fault strengthening and transformation in a high entropy alloy using in-situ neutron diffraction

Transformation induced plasticity (TRIP) leads to enhancements in ductility in low stacking fault energy (SFE) alloys, however to achieve an unconventional increase in strength simultaneously, there must be barriers to dislocation motion. While stacking faults (SFs) contribute to strengthening by impeding dislocation motion, the contribution of SF strengthening to work hardening during deformation is not well understood; as compared to dislocation slip, twinning induced plasticity (TWIP) and TRIP. Thus, we used in-situ neutron diffraction to correlate SF strengthening to work hardening behavior in a low SFE Fe₄₀Mn₂₀Cr₁₅Co₂₀Si₅ (at%) high entropy alloy, SFE ~ 6.31 mJ m⁻². Cooperative activation of multiple mechanisms was indicated by increases in SF strengthening and γ-f.c.c. → ε-h.c.p. transformation leading to a simultaneous increase in strength and ductility. The present study demonstrates the application of in-situ, neutron or X-ray, diffraction techniques to correlating SF strengthening to work hardening.

Radiological-pathological correlation of negative CT biopsy results enables high negative predictive value for thoracic malignancy

AIM

To evaluate multidisciplinary team (MDT) practice of radiological-pathological correlation of non-malignant biopsy results to examine the additive effect on the predictive values of computed tomography (CT) biopsy for malignancy and their subsequent management and outcomes.

MATERIALS AND METHODS

A service evaluation of the MDT management of non-malignant lung biopsy results (May 2014- May 2017) was undertaken.

RESULTS

Sixty patients had a non-malignant diagnosis on initial CT biopsy. Five patients were lost to follow-up leaving 55 in the final cohort. Forty-eight of the 55 patients had biopsy results classified as potentially non-specific, of which 26 were classified as concordant with radiology (e.g., organising pneumonia with compatible CT features), and 22 were classified as discordant (e.g., non-specific inflammation and yet sufficiently suspicious CT features). Patients with concordant negative pathology showed resolution (n=19) or stability (n=6) on imaging follow-up. One lesion demonstrated growth and was proven malignant on surgical resection. Discordant lesions were managed with repeat biopsy (n=8) or surgical resection (n=13), with 12 final benign diagnoses and nine malignancies. The negative predictive value of CT biopsy alone was 44/55 (80%), following repeat biopsy was 44/50 (88%), and following radiological-pathological assessment was 32/33 (97%). No patients underwent a shift in stage from time of biopsy to resection.

CONCLUSION

Combining radiological-pathological interpretation of negative biopsy results offers superior negative predictive value for lung malignancy without delayed diagnosis of lung cancer.

New frontiers in atom probe tomography: a review of research enabled by cryo and/or vacuum transfer systems

There has been a recent surge in the use of cryo and/or vacuum specimen preparation and transfer systems to broaden the scope of research enabled by the microscopy technique of atom probe tomography. This is driven by the fact that, as for many microscopes, the application of atom probes to air- and temperature-sensitive materials or wet biological specimens has previously been limited by transfer through air at room temperature. Here we provide an overview of areas of research that benefit from these new transfer and analysis protocols, as well as a review of current advances in transfer devices, environmental cells, and glove boxes for controlled specimen manipulation. This includes the study of catalysis and corrosion, biological samples, liquid-solid interfaces, natural aging, and the distribution of hydrogen in materials.

Outstanding radiation resistance of tungsten-based high-entropy alloys

A body-centered cubic W-based refractory high entropy alloy with outstanding radiation resistance has been developed. The alloy was grown as thin films showing a bimodal grain size distribution in the nanocrystalline and ultrafine regimes and a unique 4-nm lamella-like structure revealed by atom probe tomography (APT). Transmission electron microscopy (TEM) and x-ray diffraction show certain black spots appearing after thermal annealing at elevated temperatures. TEM and APT analysis correlated the black spots with second-phase particles rich in Cr and V. No sign of irradiation-created dislocation loops, even after 8 dpa, was observed. Furthermore, nanomechanical testing shows a large hardness of 14 GPa in the as-deposited samples, with near negligible irradiation hardening. Theoretical modeling combining ab initio and Monte Carlo techniques predicts the formation of Cr- and V-rich second-phase particles and points at equal mobilities of point defects as the origin of the exceptional radiation tolerance.

A survey of UK percutaneous lung biopsy practice: current practices in the era of early detection, oncogenetic profiling, and targeted treatments

AIM

To ascertain current percutaneous lung biopsy practices around the UK.

MATERIALS AND METHODS

A web-based survey was sent to all British Society of Thoracic Imaging (BSTI) and British Society of Interventional Radiology (BSIR) members (May 2017) assessing all aspects of lung biopsy practice. Responses were collected anonymously.

RESULTS

Two hundred and thirty-nine completed responses were received (28.8% response rate). Of the respondents, 48.5% worked in a teaching hospital and 51.5% in a district general hospital, while 32.6% (78/239) were specialist thoracic radiologists, 29.2% (70/239) "general" radiologists with a thoracic subspecialty interest, and 28% (67/239) interventional radiologists. Of the respondents, 30.1% (72/239) did not require pre-biopsy lung function tests (PFTs); 45.6% (108/237) stopped aspirin before the procedure; 97.5% primarily use computed tomography (CT) guidance for biopsy and 88.7% (212/239) perform core needle biopsy (CNB); and 86.6% of radiologists use a co-axial technique. There was wide variation in the number of samples routinely taken with most radiologists performing 1-2 passes (55.9%) or 3-4 passes (40.8%). Sixty-four percent reported using chest drain prevention techniques to minimise the impact of iatrogenic pneumothorax, with needle aspiration most frequent (43.9%). Timing of post-biopsy chest radiography (CXR), performed by 95.8% (228/239), also varied greatly: most commonly at either 1 hour (23%), 2 hours (24.7%), or 4 hours (22.6%). Moreover, the time of patient discharge after uncomplicated biopsy was variable, although the majority (66.1%) discharge patients after ≥4 hours.

CONCLUSION

There are striking variations among surveyed UK radiologists performing lung biopsy in decision-making, pre-biopsy work-up, post-biopsy monitoring, management of pneumothorax, and discharge. The results suggest a need for new updated national percutaneous lung biopsy guidelines.

The influence of inspiratory effort and emphysema on pulmonary nodule volumetry reproducibility

AIM

To evaluate the impact of inspiratory effort and emphysema on reproducibility of pulmonary nodule volumetry.

MATERIALS AND METHODS

Eighty-eight nodules in 24 patients with emphysema were studied retrospectively. All patients had undergone volumetric inspiratory and end-expiratory thoracic computed tomography (CT) for consideration of bronchoscopic lung volume reduction. Inspiratory and expiratory nodule volumes were measured using commercially available software. Local emphysema extent was established by analysing a segmentation area extended circumferentially around each nodule (quantified as percent of lung with density of -950 HU or less). Lung volumes were established using the same software. Differences in inspiratory and expiratory nodule volumes were illustrated using the Bland-Altman test. The influences of percentage reduction in lung volume at expiration, local emphysema extent, and nodule size on nodule volume variability were tested with multiple linear regression.

RESULTS

The majority of nodules (59/88 [67%]) showed an increased volume at expiration. Mean difference in nodule volume between expiration and inspiration was +7.5% (95% confidence interval: -24.1, 39.1%). No relationships were demonstrated between nodule volume variability and emphysema extent, degree of expiration, or nodule size.

CONCLUSION

Expiration causes a modest increase in volumetry-derived nodule volumes; however, the effect is unpredictable. Local emphysema extent had no significant effect on volume variability in the present cohort.

A bacterial-biofilm-induced oral osteolytic infection can be successfully treated by immuno-targeting an extracellular nucleoid-associated protein

Periodontal disease exemplifies a chronic and recurrent infection with a necessary biofilm component. Mucosal inflammation is a hallmark response of the host seen in chronic diseases, such as colitis, gingivitis, and periodontitis (and the related disorder peri-implantitis). We have taken advantage of our recently developed rat model of human peri-implantitis that recapitulates osteolysis, the requirement of biofilm formation, and the perpetuation of the bona fide disease state, to test a new therapeutic modality with two novel components. First we used hyperimmune antiserum directed against the DNABII family of proteins, now known to be a critical component of the extracellular matrix of bacterial biofilms. Second we delivered the antiserum as cargo in biodegradable microspheres to the site of the biofilm infection. We demonstrated that delivery of a single dose of anti-DNABII in poly(lactic-co-glycolic acid) (PLGA) microspheres induced significant resolution of experimental peri-implantitis, including marked reduction of inflammation. These data support the continued development of a DNABII protein-targeted therapeutic for peri-implantitis and other chronic inflammatory pathologies of the oral cavity in animals and humans.

UK Lung Cancer RCT Pilot Screening Trial: baseline findings from the screening arm provide evidence for the potential implementation of lung cancer screening

Background

Lung cancer screening using low-dose CT (LDCT) was shown to reduce lung cancer mortality by 20% in the National Lung Screening Trial.

Methods

The pilot UK Lung Cancer Screening (UKLS) is a randomised controlled trial of LDCT screening for lung cancer versus usual care. A population-based questionnaire was used to identify high-risk individuals. CT screen-detected nodules were managed by a pre-specified protocol. Cost effectiveness was modelled with reference to the National Lung Cancer Screening Trial mortality reduction.

Results

247 354 individuals aged 50–75 years were approached; 30.7% expressed an interest, 8729 (11.5%) were eligible and 4055 were randomised, 2028 into the CT arm (1994 underwent a CT). Forty-two participants (2.1%) had confirmed lung cancer, 34 (1.7%) at baseline and 8 (0.4%) at the 12-month scan. 28/42 (66.7%) had stage I disease, 36/42 (85.7%) had stage I or II disease. 35/42 (83.3%) had surgical resection. 536 subjects had nodules greater than 50 mm³ or 5 mm diameter and 41/536 were found to have lung cancer. One further cancer was detected by follow-up of nodules between 15 and 50 mm³ at 12 months. The baseline estimate for the incremental cost-effectiveness ratio of once-only CT screening, under the UKLS protocol, was £8466 per quality adjusted life year gained (CI £5542 to £12 569).

Conclusions

The UKLS pilot trial demonstrated that it is possible to detect lung cancer at an early stage and deliver potentially curative treatment in over 80% of cases. Health economic analysis suggests that the intervention would be cost effective—this needs to be confirmed using data on observed lung cancer mortality reduction.

Trial registration

ISRCTN 78513845.

CT screening for lung cancer: Is the evidence strong enough?

The prevailing questions at this time in both the public mind and the clinical establishment is, do we have sufficient evidence to implement lung cancer Computed Tomography (CT) screening in Europe? If not, what is outstanding? This review addresses the twelve major areas, which are critical to any decision to implement CT screening and where we need to assess whether we have sufficient evidence to proceed to a recommendation for implementation in Europe. The readiness level of these twelve categories in 2015 have been with colour coded, where green indicates we have sufficient evidence, amber is borderline evidence and red requires further evidence. Recruitment from the 'Hard to Reach' community still remains at red, while mortality data, cost effectiveness and screening interval are all categorised as amber. The integration of smoking cessation into CT screening programmes is still considered to be category amber. The US Preventive Services Task Force have recommended that CT screening is implemented in the USA utilising the NLST criteria, apart from continuing screening to 80 years of age. The cost effectiveness of the NLST was calculated to be $81,000/QALY, however, its well recognised that the costs of medical care in the USA, is far higher than that of Europe. Medicare have agreed to cover the cost of screening but have stipulated a number of stringent requirements for inclusion. To date we do not have good CT screening mortality data available in Europe and eagerly await the publication of the NELSON trial data in 2016 and then the pooled UKLS and NELSON data thereafter. However in the meantime we should start planning for implementation in Europe, especially in the areas of the radiological service provision and accreditation, as well as identifying novel mechanisms to recruit from the hardest to reach communities.

Visualizing nanoscale 3D compositional fluctuation of lithium in advanced lithium-ion battery cathodes

The distribution of cations in Li-ion battery cathodes as a function of cycling is a pivotal characteristic of battery performance. The transition metal cation distribution has been shown to affect cathode performance; however, Li is notoriously challenging to characterize with typical imaging techniques. Here laser-assisted atom probe tomography (APT) is used to map the three-dimensional distribution of Li at a sub-nanometre spatial resolution and correlate it with the distribution of the transition metal cations (M) and the oxygen. As-fabricated layered Li_1.2Ni_0.2Mn_0.6O₂ is shown to have Li-rich Li₂MO₃ phase regions and Li-depleted Li(Ni_0.5Mn_0.5)O₂ regions. Cycled material has an overall loss of Li in addition to Ni-, Mn- and Li-rich regions. Spinel LiNi_0.5Mn_1.5O₄ is shown to have a uniform distribution of all cations. APT results were compared to energy dispersive spectroscopy mapping with a scanning transmission electron microscope to confirm the transition metal cation distribution.

It is challenging to quantitatively diagnose the lithium-ion distribution in batteries. Here, the authors use laser-assisted atom probe tomography to probe the nanoscale compositional fluctuations of lithium ions in two popular lithium-ion battery cathodes before and after electrochemical cycling.

Methyl 3′-benzyl-4′-(2-chlorophenyl)-1′-methyl-2-oxospiro[indoline-3,2′-pyrrolidine]-3′-carboxylate

In the title compound, C₂₇H₂₅ClN₂O₃, the methyl­pyrrolidine ring adopts an envelope conformation with the N atom at the flap. The mean plane of the pyrrolidine ring makes dihedral angles of 82.1 (1), 84.4 (1) and 79.8 (1)°, respectively, with the adjacent benzene ring, the mean plane of the indoline ring system and the phenyl ring. The mol­ecular structure is stabilized by intra­molecular C—H⋯O hydrogen bonds. In the crystal, mol­ecules are linked into chains along [101] by N—H⋯O hydrogen bonds. C—H⋯π inter­actions are observed between the chains.

Role of Photoexcitation and Field Ionization in the Measurement of Accurate Oxide Stoichiometry by Laser-Assisted Atom Probe Tomography

The addition of pulsed lasers to atom probe tomography (APT) extends its high spatial and mass resolution capability to nonconducting materials, such as oxides. For a prototypical metal oxide, MgO, the measured stoichiometry depends strongly on the laser pulse energy and applied voltage. Very low laser energies (0.02 pJ) and high electric fields yield optimal stoichiometric accuracy. Correlated APT and aberration-corrected transmission electron microscopy (TEM) are used to establish the high density of corner and terrace sites on MgO sample surfaces before and after APT. For MgO, long-lifetime photoexcited holes localized at oxygen corner sites can assist in the creation of oxygen neutrals that may spontaneously desorb either as atomic O or as molecular O2. The observed trends are best explained by the relative field-dependent ionization of photodesorbed O or O2 neutrals. These results emphasize the importance of considering electronic excitations in APT analysis of oxide materials.

Subsurface synthesis and characterization of Ag nanoparticles embedded in MgO

Metal nanoparticles exhibit a localized surface plasmon resonance (LSPR) which is very sensitive to the size and shape of the nanoparticle and the surrounding dielectric medium. The coupling between the electromagnetic radiation and the localized surface plasmon in metallic nanoparticles results in a sizable enhancement of the incident fields, making them possible candidates for plasmonic applications. In particular, partially exposed metallic nanoparticles distributed in a dielectric matrix can provide prime locations for LSPR spectroscopy and sensing. We report the synthesis and characterization of a plasmonic substrate consisting of Ag nanoparticles partially buried in MgO. Ag nanoparticles of different shapes and size distributions were synthesized below the surface of MgO by implanting 200 keV Ag(+) ions followed by annealing at 1000 °C for 10 and 30 h. A detailed optical and structural characterization was carried out to understand the evolution of the Ag nanoparticle and size distribution inside the MgO matrix. Micro x-ray diffraction (Micro-XRD) was employed to investigate the structural properties and estimate the crystallite size. The nanoparticles evolved from a spherical to a faceted morphology with annealing time, assuming an octahedral shape truncated at the (001) planes, as visualized from aberration-corrected transmission electron microscopy (TEM) images. The nanoparticles embedded in MgO were shown to be pure metallic Ag using atom probe tomography (APT). The nanoparticles were partially exposed to the surface by employing plasma etch techniques to remove the overlaying MgO. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to study the surface morphology and obtain a height distribution for the partially exposed nanoparticles.

Methyl (E)-2-cyano-3-(6-nitro-1,3-benzodioxol-5-yl)acrylate

In the title compound, C₁₂H₈N₂O₆, the 1,3-benzodioxole ring system is essentially planar [maximum deviation = 0.036 (2) Å] and the nitro group is oriented at a dihedral angle of 15.4 (1)° with respect to its mean plane. In the crystal, moleucles are linked into C(8) [101] chains by C—H⋯O hydrogen bonds, and weak aromatic π–π stacking [centroid–centroid distance = 3.887 (1) Å] also occurs.

(E)-3-(1,3-Benzodioxol-5-yl)-2-{[N-(2-formylphenyl)-4-methylbenzenesulfon-amido]methyl}prop-2-enenitrile

In the title compound, C(25)H(20)N(2)O(5)S, the benzodioxole ring system is essentially planar [maximum deviation = 0.021 (2) Å] and forms dihedral angles of 85.2 (1) and 74.2 (1)°, respectively, with the formyl benzene and sulfonyl-bound benzene rings. In the crystal, C-H⋯O hydrogen bonds generate C(8) chains along [100] and R(3) (3)(19) ring motifs. In addition, a weak π-π inter-action [centroid-centroid distance = 3.937 (3) Å] is also observed.

2,2′-Diisopropoxy-5,5′-methylenedibenzaldehyde

Mol­ecules of the title compound, C₂₁H₂₄O₄, are located on a twofold rotation axis running through the central methyl­ene C atom. The aldehyde group is coplanar with the benzene ring [C—C—C—O = 175.7 (4) °].

Methyl (E)-2-[(2-nitro-phen-oxy)meth-yl]-3-phenyl-acrylate

The title compound, C₁₇H₁₅NO₅, adopts an E conformation with respect to the C=C double bond of the phenyl­acrylate unit. The phenyl ring and methyl acrylate group of the phenyl­acrylate unit are disordered over two sets of sites with site-occupancy ratios of 0.705 (5):0.295 (5) and 0.683 (3):0.317 (3), respectively. The mean plane through the benzene ring of the phenyl acrylate makes dihedral angles of 88.4 (8) (major component) and 86.7 (8)° (minor component) with the nitro­phen­oxy ring; the dihedral angle between the two components is 3.64 (6)°. Intra­molecular C—H⋯O interactions stabilise the molecular structure. In the crystal, C—H⋯O inter­actions result in a chain of mol­ecules running along the b axis.

Novel mixed-mode phase transition involving a composition-dependent displacive component

Solid-solid displacive, structural phase transformations typically undergo a discrete structural change from a parent to a product phase. Coupling electron microscopy, three-dimensional atom probe, and first-principles computations, we present the first direct evidence of a novel mechanism for a coupled diffusional-displacive transformation in titanium-molybdenum alloys wherein the displacive component in the product phase changes continuously with changing composition. These results have implications for other transformations and cannot be explained by conventional theories.