Combined positron emission tomography and contrast enhanced CT (PET/CeCT) is a feasible single investigation in the staging of oesophagogastric cancers: single-centre pilot study experience during the COVID-19 pandemic.

INTRODUCTION: Staging of oesophagogastric (OG) cancers usually involves endoscopy (OGD), and separate visits for contrast enhanced computed tomography (CeCT) and positron emission tomography (PET/CT). At the height of the COVID-19 pandemic, some of our patients underwent single-visit combined staging with PET/CeCT. We compare this novel pathway with standard separate imaging in time to completion of staging, to start of treatment, and cost. METHODS: We identified all patients discussed at our OG multidisciplinary team (MDT) meeting in 2020. Clinical records revealed dates of investigations and treatments. Data were tabulated in Excel, with statistical analysis in SPSS. All patients followed the same MDT process and image reviewing criteria. Costs were compared using prices supplied by finance departments. RESULTS: A total of 211 new patients were discussed at our MDT in 2020. Of these, 48 patients had combined PET/CeCT staging, and 68 had separate scans. Median time (interquartile range) in days from OGD to final imaging was 9 (6-23) for the combined group versus 21 (16-28) for the separate group (p≤0.001). Median time (days) from OGD to treatment start was 37 (29-52) for combined versus 55 (40-71) for separate (p≤0.001). No combined scans were of insufficient diagnostic quality for the MDT. PET/CeCT had a potential cost saving of £113 per patient. CONCLUSIONS: PET/CeCT allows accurate radiological staging of OG cancers with a single scan. Patients completed staging and started treatment faster, with a potential saving of £10,509 in one year. PET/CeCT has become standard staging at our trust, and we aim to incorporate radiotherapy planning images too.

A national survey investigating the impact of the COVID-19 pandemic on core and higher breast radiology training in the UK.

AIM: To investigate the impact of the COVID-19 pandemic on core and higher breast radiology training in the UK from the perspective of trainees and new consultants. MATERIALS AND METHODS: A survey comprising 25 questions was distributed to UK radiology trainees via the regional Junior Radiologists Forum representatives under the auspices of the British Society of Breast Radiology (BSBR). RESULTS: Sixty-nine eligible responses were received representing all UK training regions. Fifty-five per cent of respondents completing either a core or higher breast rotation felt that the pandemic had a negative effect on their breast training. There was an overall reduction in exposure to the key breast imaging methods when rotations took place during the pandemic. Completing a core breast rotation during the pandemic was less likely to attract trainees to higher breast training. Three out of four breast radiology consultants in their first year after receiving their Certificate of Completion of Training (CCT) felt the pandemic reduced their preparedness for becoming consultants. Positive outcomes included the increased use of online educational resources and remote multidisciplinary meetings. CONCLUSIONS: As well as having a negative impact on breast radiology training overall, the pandemic has had a detrimental effect on attracting trainees to breast radiology as a future career. It is of key importance that trainees have a positive core breast rotation as this experience appears central to many trainees' decisions to pursue higher breast training. Increased use of online learning resources has also been positively received and is a valuable approach to learning that can be maintained in the longer term.

Towards new material biomarkers for fracture risk.

Osteoporosis is a prevalent bone condition, characterised by low bone mass and increased fracture risk. Currently, the gold standard for identifying osteoporosis and increased fracture risk is through quantification of bone mineral density (BMD) using dual energy X-ray absorption (DEXA). However, the risk of osteoporotic fracture is determined collectively by bone mass, architecture and physicochemistry of the mineral composite building blocks. Thus DEXA scans alone inevitably fail to fully discriminate individuals who will suffer a fragility fracture. This study examines trabecular bone at both ultrastructure and microarchitectural levels to provide a detailed material view of bone, and therefore provides a more comprehensive explanation of osteoporotic fracture risk. Physicochemical characterisation obtained through X-ray diffraction and infrared analysis indicated significant differences in apatite crystal chemistry and nanostructure between fracture and non-fracture groups. Further, this study, through considering the potential correlations between the chemical biomarkers and microarchitectural properties of trabecular bone, has investigated the relationship between bone mechanical properties (e.g. fragility) and physicochemical material features.

Classification of fracture and non-fracture groups by analysis of coherent X-ray scatter.

Osteoporotic fractures present a significant social and economic burden, which is set to rise commensurately with the aging population. Greater understanding of the physicochemical differences between osteoporotic and normal conditions will facilitate the development of diagnostic technologies with increased performance and treatments with increased efficacy. Using coherent X-ray scattering we have evaluated a population of 108 ex vivo human bone samples comprised of non-fracture and fracture groups. Principal component fed linear discriminant analysis was used to develop a classification model to discern each condition resulting in a sensitivity and specificity of 93% and 91%, respectively. Evaluating the coherent X-ray scatter differences from each condition supports the hypothesis that a causal physicochemical change has occurred in the fracture group. This work is a critical step along the path towards developing an in vivo diagnostic tool for fracture risk prediction.

X-ray diffraction from bone employing annular and semi-annular beams.

There is a compelling need for accurate, low cost diagnostics to identify osteo-tissues that are associated with a high risk of fracture within an individual. To satisfy this requirement the quantification of bone characteristics such as 'bone quality' need to exceed that provided currently by densitometry. Bone mineral chemistry and microstructure can be determined from coherent x-ray scatter signatures of bone specimens. Therefore, if these signatures can be measured, in vivo, to an appropriate accuracy it should be possible by extending terms within a fracture risk model to improve fracture risk prediction.In this preliminary study we present an examination of a new x-ray diffraction technique that employs hollow annular and semi-annular beams to measure aspects of 'bone quality'. We present diffractograms obtained with our approach from ex vivo bone specimens at Mo Kα and W Kα energies. Primary data is parameterized to provide estimates of bone characteristics and to indicate the precision with which these can be determined.

Energy-dispersive X-ray diffraction using an annular beam.

We demonstrate material phase identification by measuring polychromatic diffraction spots from samples at least 20 mm in diameter and up to 10 mm thick with an energy resolving point detector. Within our method an annular X-ray beam in the form of a conical shell is incident with its symmetry axis normal to an extended polycrystalline sample. The detector is configured to receive diffracted flux transmitted through the sample and is positioned on the symmetry axis of the annular beam. We present the experiment data from a range of different materials and demonstrate the acquisition of useful data with sub-second collection times of 0.5 s; equating to 0.15 mAs. Our technique should be highly relevant in fields that demand rapid analytical methods such as medicine, security screening and non-destructive testing.

The effect of chemotherapy on health-related quality of life in mesothelioma: results from the SWAMP trial.

BACKGROUND: The effect of chemotherapy on health-related quality of life (HRQoL) in malignant pleural mesothelioma (MPM) is poorly understood. Patient-individualised prognostication and prediction of treatment response from chemotherapy is useful but little evidence exists to guide practice. METHOD: Consecutive patients with MPM who were fit for first-line chemotherapy with pemetrexed and cisplatin\carboplatin were recruited and followed up for a minimum of 12 months. This study focussed on the HRQoL outcomes of these patients using the EQ-5D, EORTC QLQ-C30 and LC13. RESULTS: Seventy-three patients were recruited of which 58 received chemotherapy and 15 opted for best supportive care (BSC). Compliance with HRQoL questionnaires was 98% at baseline. The chemotherapy group maintained HRQoL compared with the BSC group whose overall HRQoL fell (P=0.006) with worsening dyspnoea and pain. The impact of chemotherapy was irrespective of histological subtype although those with non-epithelioid disease had worse HRQoL at later time points (P=0.012). Additionally, those with a falling mesothelin or improvement on modified-RECIST CT at early follow-up had a better HRQoL at 16 weeks. CONCLUSIONS: HRQoL was maintained following chemotherapy compared with a self-selected BSC group. Once chemotherapy is initiated, a falling mesothelin or improved RECIST CT findings infer a quality-of-life advantage.

The South West Area Mesothelioma and Pemetrexed trial: a multicentre prospective observational study evaluating novel markers of chemotherapy response and prognostication.

BACKGROUND: Robust markers that predict prognosis and detect early treatment response in malignant pleural mesothelioma (MPM) would enhance patient care. METHODS: Consecutive patients with MPM who were considered fit for first-line chemotherapy were prospectively recruited. Patients of similar performance status opting for best supportive care were included as a comparator group. Baseline and interval CT, PET-CT and serum markers (mesothelin, fibulin-3 and neutrophil-lymphocyte ratio (NLR)) were obtained, and patients followed up for a minimum 12 months. FINDINGS: Seventy-three patients were recruited (58 chemotherapy/15 comparator arm). Baseline TGV (total glycolytic volume on PET-CT) was an independent predictor of worse overall survival (OS) (P=0.001). Change in interval TGV(baseline/after two cycles of chemotherapy) did not predict OS or chemotherapy response on CT. Baseline NLR<4 was an independent predictor of better OS (median survival 453 (IQR 272-576) days vs NLR⩾4, 257 (IQR 147-490), P=0.002). Although baseline serum mesothelin did not predict OS, a falling level at 8 weeks significantly predicted longer time to progression (TTP) (P<0.001). INTERPRETATION: Neutrophil-lymphocyte ratio and baseline TGV predict prognosis in malignant pleural mesothelioma (MPM), but PET-CT is unhelpful in monitoring chemotherapy response. Serum mesothelin is a useful early treatment response marker when measured serially during chemotherapy and may have a role in evaluating patients' treatment response.

The micro-architecture of human cancellous bone from fracture neck of femur patients in relation to the structural integrity and fracture toughness of the tissue.

Osteoporosis is clinically assessed from bone mineral density measurements using dual energy X-ray absorption (DXA). However, these measurements do not always provide an accurate fracture prediction, arguably because DXA does not grapple with 'bone quality', which is a combined result of microarchitecture, texture, bone tissue properties, past loading history, material chemistry and bone physiology in reaction to disease. Studies addressing bone quality are comparatively few if one considers the potential importance of this factor. They suffer due to low number of human osteoporotic specimens, use of animal proxies and/or the lack of differentiation between confounding parameters such as gender and state of diseased bone. The present study considers bone samples donated from patients (n = 37) who suffered a femoral neck fracture and in this very well defined cohort we have produced in previous work fracture toughness measurements (FT) which quantify its ability to resist crack growth which reflects directly the structural integrity of the cancellous bone tissue. We investigated correlations between BV/TV and other microarchitectural parameters; we examined effects that may suggest differences in bone remodelling between males and females and compared the relationships with the FT properties. The data crucially has shown that TbTh, TbSp, SMI and TbN may provide a proxy or surrogate for BV/TV. Correlations between FT critical stress intensity values and microarchitecture parameters (BV/TV, BS/TV, TbN, BS/BV and SMI) for osteoporotic cancellous tissue were observed and are for the first time reported in this study. Overall, this study has not only highlighted that the fracture model based upon BMD could potentially be improved with inclusion of other microarchitecture parameters, but has also given us clear clues as to which of them are more influential in this role.

Multimodality imaging features of hereditary multiple exostoses.

Hereditary multiple exostoses (HME) or diaphyseal aclasis is an inherited disorder characterised by the formation of multiple osteochondromas, which are cartilage-capped osseous outgrowths, and the development of associated osseous deformities. Individuals with HME may be asymptomatic or develop clinical symptoms, which prompt imaging studies. Different modalities ranging from plain radiographs to cross-sectional and nuclear medicine imaging studies can be helpful in the diagnosis and detection of complications in HME, including chondrosarcomatous transformation. We review the role and imaging features of these different modalities in HME.

The role of dual time point FDG PET imaging in the evaluation of solitary pulmonary nodules with an initial standard uptake value less than 2.5.

AIM: To evaluate the accuracy of dual time point 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) imaging in the evaluation of the mildly metabolic solitary pulmonary nodule (SPN) and to assess whether accuracy could be improved by delaying second image acquisition to 180 minutes. MATERIALS AND METHODS: Fifty-four patients were included in the study. Thirty-six had an SUV(max) <2.5 at 60 min. For these patients, two methods of interpreting the subsequent delayed FDG PET imaging at 180 min were investigated. The first method analysed the SUV(max) of SPNs on delayed imaging, in which an SUV(max) of 2.5 or more was regarded as a criterion for malignancy. The second method was retention index (RI) analysis, in which an increase of 10% or more in SUV(max) between the initial and delayed images, was regarded as an indication of malignancy. RESULTS: For the group as a whole (n=54), the sensitivity, specificity and accuracy of using an SUV(max) of 2.5 or more as an indication of malignancy at the time of initial image acquisition (60 min) was 58, 89, and 74%, respectively. For SPNs that had an initial SUV(max) <2.5 (n=36), the sensitivity, specificity, and accuracy of using an SUV(max) of 2.5 or more as a criterion for malignancy on the delayed image acquisition (180 min), was 36, 96, and 78% respectively. However, if an RI of >10% was used as a criterion for malignancy between the initial and delayed images, the sensitivity, specificity, and accuracy was 73, 80, and 78%, respectively. These results are similar to a recent paper, where image acquisition occurred at 60 and 120 min post-tracer injection. CONCLUSION: Dual time point FDG PET imaging with RI analysis, is a useful technique in evaluating SPN with an initial SUV(max) <2.5. Prolonging second image acquisition from 120 to 180 min does not appear to improve the accuracy of this technique. However, given that maximal FDG uptake by lung carcinomas is thought to be in the region of 5h, it may be that improving the accuracy of dual time point FDG PET imaging requires a more significant delay in second image acquisition in this specific subgroup.

The role of computerized tomography in the evaluation of gastrointestinal bleeding following negative or failed endoscopy: a review of current status.

Gastrointestinal bleeding remains an important cause for emergency hospital admission with a significant related morbidity and mortality. Bleeding may relate to the upper or lower gastrointestinal tracts and clinical history and examination may guide investigations to the more likely source of bleeding. The now widespread availability of endoscopic equipment has made a huge impact on the rapid identification of the bleeding source. However, there remains a large group of patients with negative or failed endoscopy, in whom additional techniques are required to identify the source of bleeding. In the past, catheter angiography and radionuclide red cell labeling techniques were the preferred 'next step' modalities used to aid in identifying a bleeding source within the gastrointestinal tract. However, these techniques are time-consuming and of limited sensitivity and specificity. In addition, catheter angiography is a relatively invasive procedure. In recent years, computerized tomography (CT) has undergone major technological advances in its speed, resolution, multiplanar techniques and angiographic abilities. It has allowed excellent visualization of the both the small and large bowel allowing precise anatomical visualization of many causes of gastrointestinal tract (GIT) bleeding. In addition, recent advances in multiphasic imaging now allow direct visualization of bleeding into the bowel. In many centers CT has therefore become the 'next step' technique in identifying a bleeding source within the GIT following negative or failed endoscopy in the acute setting. In this review article, we review the current literature and discuss the current status of CT as a modality in investigating the patient with GIT bleeding.

Imaging of Budd-Chiari syndrome.

Budd-Chiari syndrome occurs when venous outflow from the liver is obstructed. The obstruction may occur at any point from the hepatic venules to the left atrium. The syndrome most often occurs in patients with underlying thrombotic disorders such as polycythemia rubra vera, paroxysmal nocturnal hemoglobinuria and pregnancy. It may also occur secondary to a variety of tumours, chronic inflammatory diseases and infections. Imaging plays an important role both in establishing the diagnosis of Budd-Chiari syndrome as well as evaluating for underlying causes and complications such as portal hypertension. In this review article, we discuss the role of modern imaging in the evaluation of Budd-Chiari syndrome.