Radiomics-based decision support tool assists radiologists in small lung nodule classification and improves lung cancer early diagnosis.

BACKGROUND: Methods to improve stratification of small (≤15 mm) lung nodules are needed. We aimed to develop a radiomics model to assist lung cancer diagnosis. METHODS: Patients were retrospectively identified using health records from January 2007 to December 2018. The external test set was obtained from the national LIBRA study and a prospective Lung Cancer Screening programme. Radiomics features were extracted from multi-region CT segmentations using TexLab2.0. LASSO regression generated the 5-feature small nodule radiomics-predictive-vector (SN-RPV). K-means clustering was used to split patients into risk groups according to SN-RPV. Model performance was compared to 6 thoracic radiologists. SN-RPV and radiologist risk groups were combined to generate "Safety-Net" and "Early Diagnosis" decision-support tools. RESULTS: In total, 810 patients with 990 nodules were included. The AUC for malignancy prediction was 0.85 (95% CI: 0.82-0.87), 0.78 (95% CI: 0.70-0.85) and 0.78 (95% CI: 0.59-0.92) for the training, test and external test datasets, respectively. The test set accuracy was 73% (95% CI: 65-81%) and resulted in 66.67% improvements in potentially missed [8/12] or delayed [6/9] cancers, compared to the radiologist with performance closest to the mean of six readers. CONCLUSIONS: SN-RPV may provide net-benefit in terms of earlier cancer diagnosis.

Prophylactic Uterine Artery Embolization in Placenta Accreta Spectrum-An Active Intervention to Reduce Morbidity and Promote Uterine Preservation.

PURPOSE: To evaluate the feasibility and safety of early and proactive involvement of interventional radiology (IR) in the management of placenta accreta spectrum (PAS) by performing the cesarean operation and prophylactic uterine artery embolization in the IR angiography suite as a combined procedure. MATERIALS AND METHODS: This study evaluated the effectiveness and safety of prophylactic uterine artery embolization prior to placental separation in cases of antenatally proven or suspected abnormal placentation. Over a 5-year period, 16 consecutive patients with PAS underwent combined IR and obstetric intervention. In all cases, cesarean delivery was performed in the IR angiography suite. Vascular access was obtained prior to surgery with balloon placement into both internal iliac arteries. These balloons were inflated after delivery, followed by uterine artery embolization (14 of 16) if there was evidence of active postpartum bleeding or inability to deliver the placenta. RESULTS: There was no fetal or maternal mortality and no significant IR or surgical adverse events. Mean blood loss was 1900 mL. Seven patients (44%) underwent hysterectomy. CONCLUSIONS: In patients with PAS, cesarean section in the angiography suite preceded by prophylactic balloon placement and followed by uterine artery embolization was feasible, safe, and effective in preventing massive blood loss, with a 56% uterine sparing rate.

Molecular Basis of the Rapamycin Insensitivity of Target Of Rapamycin Complex 2.

Target of Rapamycin (TOR) plays central roles in the regulation of eukaryote growth as the hub of two essential multiprotein complexes: TORC1, which is rapamycin-sensitive, and the lesser characterized TORC2, which is not. TORC2 is a key regulator of lipid biosynthesis and Akt-mediated survival signaling. In spite of its importance, its structure and the molecular basis of its rapamycin insensitivity are unknown. Using crosslinking-mass spectrometry and electron microscopy, we determined the architecture of TORC2. TORC2 displays a rhomboid shape with pseudo-2-fold symmetry and a prominent central cavity. Our data indicate that the C-terminal part of Avo3, a subunit unique to TORC2, is close to the FKBP12-rapamycin-binding domain of Tor2. Removal of this sequence generated a FKBP12-rapamycin-sensitive TORC2 variant, which provides a powerful tool for deciphering TORC2 function in vivo. Using this variant, we demonstrate a role for TORC2 in G2/M cell-cycle progression.

Chest X-ray in suspected lung cancer is harmful.

OBJECTIVES: The aim of this study was to analyse the use of the chest radiograph (CXR) as the first-line investigation in primary care patients with suspected lung cancer. METHODS: Of 16,945 primary care referral CXRs (June 2018 to May 2019), 1,488 were referred for suspected lung cancer. CXRs were coded as follows: CX1, normal but a CT scan is recommended to exclude malignancy; CX2, alternative diagnosis; or CX3, suspicious for cancer. Kaplan-Meier survival analysis was undertaken by stratifying patients according to their CX code. RESULTS: In the study period, there were 101 lung cancer diagnoses via a primary care CXR pathway. Only 10% of patients with a normal CXR (CX1) underwent subsequent CT and there was a significant delay in lung cancer diagnosis in these patients (p < 0.001). Lung cancer was diagnosed at an advanced stage in 50% of CX1 patients, 38% of CX2 patients and 57% of CX3 patients (p = 0.26). There was no survival difference between CX codes (p = 0.42). CONCLUSION: Chest radiography in the investigation of patients with suspected lung cancer may be harmful. This strategy may falsely reassure in the case of a normal CXR and prioritises resources to advanced disease. KEY POINTS: • Half of all lung cancer diagnoses in a 1-year period are first investigated with a chest X-ray. • A normal chest X-ray report leads to a significant delay in the diagnosis of lung cancer. • The majority of patients with a normal or abnormal chest X-ray have advanced disease at diagnosis and there is no difference in survival outcomes based on the chest X-ray findings.

Automated calculation of the right ventricle to left ventricle ratio on CT for the risk stratification of patients with acute pulmonary embolism.

OBJECTIVES: To assess the feasibility and reliability of the use of artificial intelligence post-processing to calculate the RV:LV diameter ratio on computed tomography pulmonary angiography (CTPA) and to investigate its prognostic value in patients with acute PE. METHODS: Single-centre, retrospective study of 101 consecutive patients with CTPA-proven acute PE. RV and LV volumes were segmented on 1-mm contrast-enhanced axial slices and maximal ventricular diameters were derived for RV:LV ratio using automated post-processing software (IMBIO LLC, USA) and compared to manual analysis in two observers, via intraclass coefficient correlation analysis. Each CTPA report was analysed for mention of the RV:LV ratio and compared to the automated RV:LV ratio. Thirty-day all-cause mortality post-CTPA was recorded. RESULTS: Automated RV:LV analysis was feasible in 87% (n = 88). RV:LV ratios ranged from 0.67 to 2.43, with 64% (n = 65) > 1.0. There was very strong agreement between manual and automated RV:LV ratios (ICC = 0.83, 0.77-0.88). The use of automated analysis led to a change in risk stratification in 45% of patients (n = 40). The AUC of the automated measurement for the prediction of all-cause 30-day mortality was 0.77 (95% CI: 0.62-0.99). CONCLUSION: The RV:LV ratio on CTPA can be reliably measured automatically in the majority of real-world cases of acute PE, with perfect reproducibility. The routine use of this automated analysis in clinical practice would add important prognostic information in patients with acute PE. KEY POINTS: • Automated calculation of the right ventricle to left ventricle ratio was feasible in the majority of patients and demonstrated perfect intraobserver variability. • Automated analysis would have added important prognostic information and altered risk stratification in the majority of patients. • The optimal cut-off value for the automated right ventricle to left ventricle ratio was 1.18, with a sensitivity of 100% and specificity of 54% for the prediction of 30-day mortality.

Trajectory of radiographic change over a decade: the effect of transition from conventional synthetic disease-modifying antirheumatic drugs to anti-tumour necrosis factor in patients with psoriatic arthritis.

Objectives: To describe the trajectory of radiographic progression among patients with PsA who transitioned from conventional synthetic DMARDs to anti-TNF-α inhibitors in routine care. Methods: A retrospective sample of patients with PsA (ClASsification criteria for Psoriatic ARthritis) was taken from the Bath longitudinal cohort. All patients had radiographs of the hands and feet taken: 5 years before (T0), at the time of (T1) and 5 years after (T2) commencing anti-TNF treatment. Radiographs were scored blinded using the PsA-modified Sharp-van der Heijde score (mSvdHS) and for osteoproliferation (Psoriatic Arthritis Ratingen Score) by A.Allard, A.Antony and W.T. This sample size was calculated to ensure 90% power to determine the smallest detectable difference of the mSvdHS to a 5% significance level. Cumulative probability plots were used to determine the probability of radiographic progression pre- (T0-T1) and post- (T1-T2) anti-TNF treatment. Results: Eighty-four radiographs from 28 patients were selected for inclusion. The median [interquartile range (IQR)] disease duration at baseline (T0) was 8.5 (0-19.5) years. The interval between T0-T1 and T1-T2 was 4.2 years (3.34-6.65) and 4.9 years (4.25-5.87), respectively. The median mSvdHS at baseline (T0) was 8.5 (IQR 1.75-27.5). The median (IQR) rate of change in mSvdHS per year reduced after commencing anti-TNF, from 2.1 (0.88-3.92) between T0-T1 to 1.0 (IQR 0.05-2.35) between T1-T2 (P = 0.012). Conclusion: The trajectory of damage accumulation over a 10-year period in this observational clinical cohort is low overall. The rate of radiographic damage as measured by the mSvdHS slows following commencement of anti-TNF.

Structural definition of the lysine swing in Arabidopsis thaliana PDX1: Intermediate channeling facilitating vitamin B6 biosynthesis.

Vitamin B6 is indispensible for all organisms, notably as the coenzyme form pyridoxal 5'-phosphate. Plants make the compound de novo using a relatively simple pathway comprising pyridoxine synthase (PDX1) and pyridoxine glutaminase (PDX2). PDX1 is remarkable given its multifaceted synthetic ability to carry out isomerization, imine formation, ammonia addition, aldol-type condensation, cyclization, and aromatization, all in the absence of coenzymes or recruitment of specialized domains. Two active sites (P1 and P2) facilitate the plethora of reactions, but it is not known how the two are coordinated and, moreover, if intermediates are tunneled between active sites. Here we present X-ray structures of PDX1.3 from Arabidopsis thaliana, the overall architecture of which is a dodecamer of (ß/α)8 barrels, similar to the majority of its homologs. An apoenzyme structure revealed that features around the P1 active site in PDX1.3 have adopted inward conformations consistent with a catalytically primed state and delineated a substrate accessible cavity above this active site, not noted in other reported structures. Comparison with the structure of PDX1.3 with an intermediate along the catalytic trajectory demonstrated that a lysine residue swings from the distinct P2 site to the P1 site at this stage of catalysis and is held in place by a molecular catch and pin, positioning it for transfer of serviced substrate back to P2. The study shows that a simple lysine swinging arm coordinates use of chemically disparate sites, dispensing with the need for additional factors, and provides an elegant example of solving complex chemistry to generate an essential metabolite.

Axial Disease in Psoriatic Arthritis study: defining the clinical and radiographic phenotype of psoriatic spondyloarthritis.

OBJECTIVES: To compare the prevalence, clinical and radiographic characteristics of psoriatic spondyloarthritis (PsSpA) in psoriatic arthritis (PsA), with ankylosing spondylitis (AS). METHODS: A prospective single-centre cross-sectional observational study recruited consecutive PsA and AS cases. Participants completed outcome measures, and underwent clinical examination, axial radiographic scoring and HLA-sequencing. Multivariable analyses are presented. RESULTS: The 402 enrolled cases (201 PsA, 201 AS; fulfilling classification criteria for respective conditions) were reclassified based upon radiographic axial disease and psoriasis, as: 118 PsSpA, 127 peripheral-only PsA (pPsA), and 157 AS without psoriasis (AS) cases. A significant proportion of patients with radiographic axial disease had PsSpA (118/275; 42.91%), and often had symptomatically silent axial disease (30/118; 25.42%). Modified New York criteria for AS were fulfilled by 48/201 (23.88%) PsA cases, and Classification of Psoriatic Arthritis criteria by 49/201 (24.38%) AS cases. pPsA compared with PsSpA cases had a lower frequency of HLA-B*27 (OR 0.12; 95% CI 0.05 to 0.25). Disease activity, metrology and disability were comparable in PsSpA and AS. A significant proportion of PsSpA cases had spondylitis without sacroiliitis (39/118; 33.05%); they less frequently carried HLA-B*27 (OR 0.11; 95% CI 0.04 to 0.33). Sacroiliac joint complete ankylosis (adjusted OR, ORadj 2.96; 95% CI 1.42 to 6.15) and bridging syndesmophytes (ORadj 2.78; 95% CI 1.49 to 5.18) were more likely in AS than PsSpA. Radiographic axial disease was more severe in AS than PsSpA (Psoriatic Arthritis Spondylitis Radiology Index Score: adjusted incidence risk ratio 1.13; 95% CI 1.09 to 1.19). CONCLUSIONS: In a combined cohort of patients with either PsA or AS from a single centre, 24% fulfilled classification criteria for both conditions. The pattern of axial disease was influenced significantly by the presence of skin psoriasis and HLA-B*27.

Cloning, expression, purification, and characterisation of the HEAT-repeat domain of TOR from the thermophilic eukaryote Chaetomium thermophilum.

The Target of Rapamycin Complex is a central controller of cell growth and differentiation in eukaryotes. Its global architecture has been described by cryoelectron microscopy, and regions of its central TOR protein have been described by X-ray crystallography. However, the N-terminal region of this protein, which consists of a series of HEAT repeats, remains uncharacterised at high resolution, most likely due to the absence of a suitable purification procedure. Here, we present a robust method for the preparation of the HEAT-repeat domain, utilizing the thermophilic fungus Chaetomium thermophilum as a source organism. We describe construct design and stable expression in insect cells. An efficient two-step purification procedure is presented, and the purified product is characterised by SEC and MALDI-TOF MS. The methods described pave the way for a complete high-resolution characterisation of this elusive region of the TOR protein.

Evaluation of a noise reduction imaging technology in iliac digital subtraction angiography: noninferior clinical image quality with lower patient and scatter dose.

PURPOSE: To determine whether equivalent-quality images can be obtained from digital subtraction angiography (DSA) of the iliac artery after implementation of a novel imaging technology that reduces patient and scatter x-ray dose. MATERIALS AND METHODS: Imaging using two randomly ordered DSA runs was performed in 51 adults scheduled for iliac artery angiography or intervention or both. One DSA run used standard acquisition chain and image processing algorithms (referred to as " reference DSA"), and the other DSA run used dose-reduction and real-time advanced image noise reduction technology (referred to as "study DSA"). The quality of each pair of runs, consecutively performed without changes in working projection or injection parameters, was independently rated by five radiologists blinded to the imaging technology used. Patient radiation dose was evaluated using air kerma and dose area product, and scatter dose was evaluated using three dosimeters (DoseAware, Philips Healthcare, Best, The Netherlands), located at fixed positions. RESULTS: Comparable image pairs were available in 48 patients. There were 44 patients undergoing treatment involving the common (n = 33) or external (n = 29) iliac arteries. Study DSA images were rated as equal to or better than reference DSA images for 96% of comparisons, with an average overall agreement among raters of 0.93 (95% confidence interval, 0.65-0.96). Mean patient radiation dose (n = 48) and scatter dose rate for the three dosimeters (n = 50) was 83% ± 5 and 69% ± 10 lower, respectively, using the study technology (P < .001). CONCLUSIONS: Iliac artery DSA performed using a dose-reduction and real-time advanced image noise reduction technology results in image quality that is noninferior to conventional DSA but with significantly lower patient and scatter radiation exposure (P < .001).

Stopping anticoagulation for isolated or incidental pulmonary embolism: the STOPAPE RCT protocol.

Research question: Is withholding anticoagulation for patients with isolated or incidental subsegmental pulmonary embolism clinically and cost-effective compared with full anticoagulation for 3 months? Background: There has been an increase in the diagnosis of subsegmental pulmonary embolism since the advent of computed tomography pulmonary angiogram to investigate patients with suspected pulmonary embolism. Subsegmental pulmonary embolism is not often detectable with older nuclear medicine-based diagnostic imaging for ventilation/perfusion mismatch. The case fatality of pulmonary embolism has reduced as subsegmental pulmonary embolism diagnoses from computed tomography pulmonary angiogram have increased. There is growing equipoise about the optimal treatment for patients with subsegmental pulmonary embolism, given that full anticoagulation has significant risks of bleeding and subsegmental pulmonary embolism was not often diagnosed previously with ventilation/perfusion scanning and therefore most likely left predominantly untreated prior to the introduction of computed tomography pulmonary angiogram scanning. Objectives: Determine whether withholding anticoagulation for isolated or incidental subsegmental pulmonary embolism (i.e. subsegmental pulmonary embolism with no coexisting deep-vein thrombosis) reduces the harms of recurrent thromboembolism and major bleeding compared with 3 months of full anticoagulation at 3, 6 and 12 months. Determine the rate of complications of anticoagulation therapy (predominantly bleeding) in patients with isolated subsegmental pulmonary embolism. Determine whether not treating isolated subsegmental pulmonary embolism is acceptable to clinicians and patients. Determine the reclassification rate of subsegmental pulmonary embolism diagnoses made by general reporting radiologists when reviewed by specialist respiratory radiologists and develop a set of rules to improve general radiologists' diagnoses of subsegmental pulmonary embolism. Assess cost-effectiveness of not treating patients with isolated subsegmental pulmonary embolism with anticoagulation, taking a health service perspective. Methods: Prospective individually randomised open controlled trial with blinded end-point committee assessment for outcomes, powered for non-inferiority for recurrent venous thromboembolism and for superiority for bleeding events. An internal pilot phase is included for feasibility and acceptability of no anticoagulation. We planned to recruit 1466 patients from at least 50 acute hospital sites. Allowing for a dropout rate of 15%, this would have given us 90% power to detect a reduction in major and clinically relevant non-major bleeding from 7.3% in the anticoagulation arm to 3% in the intervention arm. We were powered to determine that a strategy of no anticoagulation was non-inferior to anticoagulation with an upper margin of a 2.3% increase in recurrent venous thromboembolism from an expected rate of 2% in those who receive full anticoagulation. We also planned to undertake a study comparing acute reporting radiologists' diagnoses of subsegmental pulmonary embolism from all computed tomography pulmonary angiograms with specialist respiratory radiologists. This would have allowed us to determine safety in the pilot study (i.e. patients with pulmonary embolism that was in fact larger than subsegmental would have been identified) and develop guidance for subsegmental pulmonary embolism diagnosis for general radiologists. Patients with lived experience of thrombosis contributed to all aspects of the trial design and were part of the Trial Management Group. Progress of study: The STOPAPE trial was stopped prematurely due to a low recruitment rate in the wake of the COVID pandemic and prioritisation of recovery of the National Institute for Health and Care Research research portfolio. There are no outcome data available for this trial. Separate NIHR Library publications will detail the linked qualitative study examining the views of patients and clinicians around withholding anticoagulation for isolated subsegmental pulmonary embolism as well as presenting all collected data of recruited patients. Funding: This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number NIHR128073. A plain language summary of this research article is available on the NIHR Journals Library Website https://doi.org/10.3310/HRCW7937.

Pulmonary embolism is a potentially serious condition, whereby blood clots cause a blockage of the blood supply to the lungs. The diagnosis of pulmonary embolism is made with a scan of the lungs, by showing areas where blood cannot get through the vessels easily due to blood clots. The treatment of pulmonary embolism includes anticoagulant medication ('blood thinners') that is taken over months and includes warfarin, an injectable form of heparin and directly acting oral anticoagulants. These medications work by preventing new clots from forming while the body's own mechanisms break down the clots. As the scanning technology for pulmonary embolism has become more sensitive, smaller clots are being diagnosed. However, small pulmonary embolisms may not cause any symptoms and may be found incidentally on scans performed for other reasons. In these situations, it is unclear whether treatment is required for the pulmonary embolism. These clots in smaller blood vessels away from the centre of the lungs (subsegmental pulmonary embolism) may be removed by the body's own mechanisms for dissolving clots without needing medications. Anticoagulant medication can cause side effects in some patients such as bleeding. For the anticoagulant medication to be appropriate in these smaller pulmonary embolisms, the benefits from preventing future blood clots (pulmonary embolism and deep-vein thrombosis) would need to outweigh the potential risks from the medication side effects. The STOPAPE study aimed to answer this question by testing whether we can safely withhold anticoagulation from patients diagnosed with subsegmental pulmonary embolism. Although we aimed to enrol 1466 patients in the trial with half getting usual care of anticoagulation and half getting no anticoagulation, we could not recruit patients quickly enough to the trial and, as a result, we could not continue with the STOPAPE study. This study protocol is published to help future research teams that wish to answer this research question.

Screening success: A virtual MDT can reduce the number of patients requiring respiratory follow-up post-COVID-19 pneumonia in line with British Thoracic Society guidance.

Introduction and objectivesThe ongoing respiratory sequelae of COVID-19 pneumonia remain unclear, and the ideal follow-up of these patients is still a work in progress. We describe our experience of using a pre-follow-up multidisciplinary team (MDT) to decide the follow-up stream in patients hospitalised for COVID-19 pneumonia. METHODS: We reviewed all patients with a clinico-radiological diagnosis of COVID-19 admitted to hospital during a 3-month period and assigned a follow-up stream based on British Thoracic Society guidance. RESULTS: We changed the follow-up pathway in 71% (277/392) and refined the pathway in 67% (261/392) of indeterminate cases. We also created an automated process for the general practitioner to book follow-up imaging and will use this process going forward. CONCLUSION: These findings highlight the importance of the MDT review of cases with suspected COVID-19 pneumonia prior to clinic attendance to ensure appropriate patients are followed up and to optimise utilisation of outpatient imaging and clinics.

Long-term follow-up of treatment of pulmonary arteriovenous malformations with AMPLATZER Vascular Plug and AMPLATZER Vascular Plug II devices.

PURPOSE: To assess the feasibility, complications, and long-term success of embolization of pulmonary arteriovenous malformations (PAVMs) with the AMPLATZER Vascular Plug and AMPLATZER Vascular Plug II. MATERIALS AND METHODS: The study included 15 consecutive patients (19 embolization episodes) who had embolization of PAVMs between April 2004 and April 2009 with an AMPLATZER Vascular Plug or AMPLATZER Vascular Plug II. There were 4 men and 11 women, with a mean age of 56 years (range 24-74 years). A prospective database of all cases of PAVM embolization is kept in the department. Patient history, detailed procedural records, and clinical and radiological follow-up were reviewed. RESULTS: Among the 19 PAVMs, an AMPLATZER Vascular Plug was deployed in 11, and an AMPLATZER Vascular Plug II was deployed in 8. The technical success of the procedure was 100% for PAVM occlusion; 30-day mortality in the group was zero. Successful radiologic follow-up with the AMPLATZER Vascular Plug was a mean of 28 months (range 0-60 months) and with the AMPLATZER Vascular Plug II was a mean of 18 months (range 12-36 months). There was one recanalization of an AMPLATZER Vascular Plug 36 months after embolization giving an annual event rate of 0.03 recanalizations per AMPLATZER Vascular Plug or AMPLATZER Vascular Plug II per year. There were no major complications. Clinically, there was one (1 of 18 cases [5%]) immediate complication of chest pain that resolved in 24 hours with simple analgesia. There were no early or late clinical complications. CONCLUSIONS: The treatment of PAVM with either an AMPLATZER Vascular Plug or an AMPLATZER Vascular Plug II is safe and effective and associated with a low reintervention rate. Further follow-up is ongoing to ensure continued occlusion of treated PAVMs.

Three-year follow-up of fenestrated thoracoabdominal stent graft bridging an endovascular thoracic stent graft and a surgical abdominal aortic graft.

This case report describes repair of a type I endoleak at the distal landing zone of a thoracic aortic stent graft by endovascular placement of a thoracoabdominal fenestrated stent graft (Cook, Brisbane, Australia). The fenestrated stent graft was interposed between a previous abdominal aortic aneurysm (AAA) Gelsoft tube graft (Sulzer Vascutek Ltd, Inchinnan, United Kingdom) and two overlapping Zenith thoracic endografts (Cook Inc, Bloomington, Indiana). Placement was made more complex because the distal thoracic endograft had rotated into a horizontal position. At 3-year clinical and computed tomography (CT) follow-up, continued clinical and radiologic success was shown with no further intervention required.

Computed tomography appearances of the lung parenchyma in pulmonary hypertension.

Computed tomography (CT) is a valuable tool in the workup of patients under investigation for pulmonary hypertension (PH) and may be the first test to suggest the diagnosis. CT parenchymal lung changes can help to differentiate the aetiology of PH. CT can demonstrate interstitial lung disease, emphysema associated with chronic obstructive pulmonary disease, features of left heart failure (including interstitial oedema), and changes secondary to miscellaneous conditions such as sarcoidosis. CT also demonstrates parenchymal changes secondary to chronic thromboembolic disease and venous diseases such as pulmonary venous occlusive disease (PVOD) and pulmonary capillary haemangiomatosis (PCH). It is important for the radiologist to be aware of the various manifestations of PH in the lung, to help facilitate an accurate and timely diagnosis. This pictorial review illustrates the parenchymal lung changes that can be seen in the various conditions causing PH.

Diagnostic test accuracy of artificial intelligence analysis of cross-sectional imaging in pulmonary hypertension: a systematic literature review.

OBJECTIVES: To undertake the first systematic review examining the performance of artificial intelligence (AI) applied to cross-sectional imaging for the diagnosis of acquired pulmonary arterial hypertension (PAH). METHODS: Searches of Medline, Embase and Web of Science were undertaken on 1 July 2020. Original publications studying AI applied to cross-sectional imaging for the diagnosis of acquired PAH in adults were identified through two-staged double-blinded review. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies and Checklist for Artificial Intelligence in Medicine frameworks. Narrative synthesis was undertaken following Synthesis Without Meta-Analysis guidelines. This review received no funding and was registered in the International Prospective Register of Systematic Reviews (ID:CRD42020196295). RESULTS: Searches returned 476 citations. Three retrospective observational studies, published between 2016 and 2020, were selected for data-extraction. Two methods applied to cardiac-MRI demonstrated high diagnostic accuracy, with the best model achieving AUC=0.90 (95% CI: 0.85-0.93), 89% sensitivity and 81% specificity. Stronger results were achieved using cardiac-MRI for classification of idiopathic PAH, achieving AUC=0.97 (95% CI: 0.89-1.0), 96% sensitivity and 87% specificity. One study reporting CT-based AI demonstrated lower accuracy, with 64.6% sensitivity and 97.0% specificity. CONCLUSIONS: Automated methods for identifying PAH on cardiac-MRI are emerging with high diagnostic accuracy. AI applied to cross-sectional imaging may provide non-invasive support to reduce diagnostic delay in PAH. This would be helped by stronger solutions in other modalities. ADVANCES IN KNOWLEDGE: There is a significant shortage of research in this important area. Early detection of PAH would be supported by further research advances on the promising emerging technologies identified.

Reporting incidental coronary, aortic valve and cardiac calcification on non-gated thoracic computed tomography, a consensus statement from the BSCI/BSCCT and BSTI.

Incidental coronary and cardiac calcification are frequent findings on non-gated thoracic CT. We recommend that the heart is reviewed on all CT scans where it is visualised. Coronary artery calcification is a marker of coronary artery disease and it is associated with an adverse prognosis on dedicated cardiac imaging and on non-gated thoracic CT performed for non-cardiac indications, both with and without contrast. We recommend that coronary artery calcification is reported on all non-gated thoracic CT using a simple patient-based score (none, mild, moderate, severe). Furthermore, we recommend that reports include recommendations for subsequent management, namely the assessment of modifiable cardiovascular risk factors and, if the patient has chest pain, assessment as per standard guidelines. In most cases, this will not necessitate additional investigations. Incidental aortic valve calcification may also be identified on non-gated thoracic CT and should be reported, along with ancillary findings such as aortic root dilation. Calcification may occur in other parts of the heart including mitral valve/annulus, pericardium and myocardium, but in many cases these are an incidental finding without clinical significance.

Towards nationally curated data archives for clinical radiology image analysis at scale: Learnings from national data collection in response to a pandemic.

The prevalence of the coronavirus SARS-CoV-2 disease has resulted in the unprecedented collection of health data to support research. Historically, coordinating the collation of such datasets on a national scale has been challenging to execute for several reasons, including issues with data privacy, the lack of data reporting standards, interoperable technologies, and distribution methods. The coronavirus SARS-CoV-2 disease pandemic has highlighted the importance of collaboration between government bodies, healthcare institutions, academic researchers and commercial companies in overcoming these issues during times of urgency. The National COVID-19 Chest Imaging Database, led by NHSX, British Society of Thoracic Imaging, Royal Surrey NHS Foundation Trust and Faculty, is an example of such a national initiative. Here, we summarise the experiences and challenges of setting up the National COVID-19 Chest Imaging Database, and the implications for future ambitions of national data curation in medical imaging to advance the safe adoption of artificial intelligence in healthcare.

Long-term outcomes of low-dose catheter-directed thrombolytic therapy: a 5-year single-center experience.

PURPOSE: To determine immediate and long-term outcomes following catheter-directed intraarterial thrombolysis of occluded native arteries and infrainguinal vein grafts by using low-dose tissue-type plasminogen activator (tPA) in patients with lower limb ischemia. MATERIALS AND METHODS: One hundred eleven intraarterial thrombolysis procedures were performed in 96 patients during the 2-year study period. Patient records were available for retrospective review in 85 thrombolytic procedures performed in 74 (77%) of the 96 patients. Forty-one native vessels (four iliac, 24 superficial/common femoral, and 13 popliteal/below-knee vessels), six iliac stents, and 38 infrainguinal vein grafts were treated by using a low-dose (0.5 mg/h recombinant tPA) catheter-directed thrombolytic regimen. Procedural success was based on angiographic and clinical outcomes, and the need for further reconstructive surgery or amputation was documented. RESULTS: Intraarterial thrombolysis was successful in 76%, was partially successful in 11%, and failed in 13%. Adjunctive angioplasty was performed in 33 of 55 patients (60%) with successful lysis, and immediate reconstructive surgery was required in five patients. There was one episode of puncture site bleeding and one gastrointestinal hemorrhage but no procedure-related deaths at 30 days. After a median follow-up of 6.5 years, 30 of the 55 patients (55%) who underwent successful thrombolysis required no further surgical intervention; however, further surgery was required in 45% of patients after a mean interval of 301 days (range, 2-1,344 days), including 10 (18%) amputations (six major and four minor). CONCLUSIONS: Low-dose intraarterial thrombolysis is safe and effective, delaying and dramatically reducing the need for surgical intervention in lower limb ischemia due to native vessel or infrainguinal graft occlusion.