Diagnostic performance of chest CT average intensity projection (AIP) reconstruction for the assessment of pleuro-parenchymal abnormalities.

AIM: The comparison between chest x-ray (CXR) and computed tomography (CT) images is commonly required in clinical practice to assess the evolution of chest pathological manifestations. Intrinsic differences between the two techniques, however, limit reader confidence in such a comparison. CT average intensity projection (AIP) reconstruction allows obtaining "synthetic" CXR (s-CXR) images, which are thought to have the potential to increase the accuracy of comparison between CXR and CT imaging. We aim at assessing the diagnostic performance of s-CXR imaging in detecting common pleuro-parenchymal abnormalities. MATERIALS AND METHODS: 142 patients who underwent chest CT examination and CXR within 24 hours were enrolled. CT was the standard of reference. Both conventional CXR (c-CXR) and s-CXR images were retrospectively reviewed for the presence of consolidation, nodule/mass, linear opacities, reticular opacities, and pleural effusion by 3 readers in two separate sessions. Sensitivity, specificity, accuracy and their 95% confidence interval were calculated for each reader and setting and tested by McNemar test. Inter-observer agreement was tested by Cohen's K test and its 95%CI. RESULTS: Overall, s-CXR sensitivity ranged 45-67% for consolidation, 12-28% for nodule/mass, 17-33% for linear opacities, 2-61% for reticular opacities, and 33-58% for pleural effusion; specificity 65-83%, 83-94%, 94-98%, 93-100% and 79-86%; accuracy 66-68%, 74-79%, 89-91%, 61-65% and 68-72%, respectively. K values ranged 0.38-0.50, 0.05-0.25, -0.05-0.11, -0.01-0.15, and 0.40-0.66 for consolidation, nodule/mass, linear opacities, reticular opacities, and pleural effusion, respectively. CONCLUSION: S-CXR images, reconstructed with AIP technique, can be compared with conventional images in clinical practice and for educational purposes.

Baseline computed tomography screening and blood microRNA predict lung cancer risk and define adequate intervals in the BioMILD trial.

BACKGROUND: Large randomized trials have demonstrated that lung cancer (LC) screening with low-dose computed tomography (LDCT) reduces LC mortality in heavy smokers. We previously showed in the MILD screening trial that the combination of a prespecified circulating microRNA (miRNA) signature classifier (MSC) and LDCT improves the accuracy of LDCT alone. The primary aim of the prospective BioMILD study was to assess the additional value of the blood MSC assay at the time of baseline LDCT with the goal of personalizing LC screening intervals. PATIENTS AND METHODS: The study enrolled 4119 volunteers from January 2013 to March 2016, with a median follow-up of 5.3 years. Baseline LDCT and miRNAs stratified participants into four groups: CT-/MSC- (n = 2664; 64.7%); CT-/MSC+ (n = 800; 19.4%); CT+/MSC- (n = 446; 10.8%); and CT+/MSC+ (n = 209; 5.1%). As per the protocol, those in the CT-/MSC- and CT-/MSC+ groups were allocated to LDCT repeat at 3-year and 1-year intervals; CT+ participants were allocated for 1-year or earlier intervals on the basis of LDCT features independent of MSC results. RESULTS: CT+ participants had a 15.8-fold higher 4-year LC incidence than CT- participants (95% confidence interval 10.34-24.05), and MSC+ participants had a 2.0-fold higher 4-year LC incidence than MSC- participants (95% confidence interval 1.40-2.90); there was no evidence that the MSC effect differed between CT+ and CT- participants. LC incidence at 4 years was 0.8% in CT-/MSC-, 1.1% in CT-/MSC+, 10.8% in CT+/MSC-, and 20.1% in CT+/MSC+ participants. LC mortality rates at 5 years in the four risk groups were 0.5 in CT-/MSC-, 1.5 in CT-/MSC+, 4.2 in CT+/MSC-, and 10.1 in CT+/MSC+. CONCLUSION: The combined use of LDCT and blood miRNAs at baseline predicts individual LC incidence and mortality, with a major effect of MSC for LDCT-positive individuals. These findings may have important implications in personalizing screening intervals.

COVID-19 pneumonia imaging follow-up: when and how? A proposition from ESTI and ESR.

This document from the European Society of Thoracic Imaging (ESTI) and the European Society of Radiology (ESR) discusses the role of imaging in the long-term follow-up of COVID-19 patients, to define which patients may benefit from imaging, and what imaging modalities and protocols should be used. Insights into imaging features encountered on computed tomography (CT) scans and potential pitfalls are discussed and possible areas for future review and research are also included. KEY POINTS: • Post-COVID-19 pneumonia changes are mainly consistent with prior organizing pneumonia and are likely to disappear within 12 months of recovery from the acute infection in the majority of patients. • At present, with the longest series of follow-up examinations reported not exceeding 12 months, the development of persistent or progressive fibrosis in at least some individuals cannot yet be excluded. • Residual ground glass opacification may be associated with persisting bronchial dilatation and distortion, and might be termed "fibrotic-like changes" probably consistent with prior organizing pneumonia.

Milestones towards lung cancer screening implementation.

The European Society of Radiology (ESR) and European Respiratory Society (ERS) published their joint statement paper on lung cancer screening (LCS), on 12 February 2020. This document joins and completes previous recommendations on LCS with specific emphasis on the analysis of issues encountered in the practical implementation of LCS in the community. Major milestones to enable the most efficient and equal dissemination of LCS are recognised as engagement of all stakeholders (e.g. candidate/participant, general practitioners, up to the specialised LCS facility), quality assurance, and primary prevention in the form of provision of counselling for smoking cessation.

Prolonged lung cancer screening reduced 10-year mortality in the MILD trial: new confirmation of lung cancer screening efficacy.

BACKGROUND: The National Lung Screening Trial showed that lung cancer (LC) screening by three annual rounds of low-dose computed tomography (LDCT) reduces LC mortality. We evaluated the benefit of prolonged LDCT screening beyond 5 years, and its impact on overall and LC specific mortality at 10 years. DESIGN: The Multicentric Italian Lung Detection (MILD) trial prospectively randomized 4099 participants, to a screening arm (n = 2376), with further randomization to annual (n = 1190) or biennial (n = 1186) LDCT for a median period of 6 years, or control arm (n = 1723) without intervention. Between 2005 and 2018, 39 293 person-years of follow-up were accumulated. The primary outcomes were 10-year overall and LC specific mortality. Landmark analysis was used to test the long-term effect of LC screening, beyond 5 years by exclusion of LCs and deaths that occurred in the first 5 years. RESULTS: The LDCT arm showed a 39% reduced risk of LC mortality at 10 years [hazard ratio (HR) 0.61; 95% confidence interval (CI) 0.39-0.95], compared with control arm, and a 20% reduction of overall mortality (HR 0.80; 95% CI 0.62-1.03). LDCT benefit improved beyond the 5th year of screening, with a 58% reduced risk of LC mortality (HR 0.42; 95% CI 0.22-0.79), and 32% reduction of overall mortality (HR 0.68; 95% CI 0.49-0.94). CONCLUSIONS: The MILD trial provides additional evidence that prolonged screening beyond 5 years can enhance the benefit of early detection and achieve a greater overall and LC mortality reduction compared with NLST trial. CLINICALTRIALS.GOV IDENTIFIER: NCT02837809.

Lung cancer screening with low-dose CT in Europe: strength and weakness of diverse independent screening trials.

A North American trial reported a significant reduction of lung cancer mortality and overall mortality as a result of annual screening using low-dose computed tomography (LDCT). European trials prospectively tested a variety of possible screening strategies. The main topics of current discussion regarding the optimal screening strategy are pre-test selection of the high-risk population, interval length of LDCT rounds, definition of positive finding, and post-test apportioning of lung cancer risk based on LDCT findings. Despite the current lack of statistical evidence regarding mortality reduction, the European independent diverse strategies offer a multi-perspective view on screening complexity, with remarkable indications for improvements in cost-effectiveness and harm-benefit balance. The UKLS trial reported the advantage of a comprehensive and simple risk model for selection of patients with 5% risk of lung cancer in 5 years. Subjective risk prediction by biological sampling is under investigation. The MILD trial reported equal efficiency for biennial and annual screening rounds, with a significant reduction in the total number of LDCT examinations. The NELSON trial introduced volumetric quantification of nodules at baseline and volume-doubling time (VDT) for assessment of progression. Post-test risk refinement based on LDCT findings (qualitative or quantitative) is under investigation. Smoking cessation remains the most appropriate strategy for mortality reduction, and it must therefore remain an integral component of any lung cancer screening programme.

Hypersensitivity Pneumonitis: A Comprehensive Review.

Hypersensitivity pneumonitis (HP), also known as extrinsic allergic alveolitis, is a complex pulmonary syndrome mediated by the immune system and caused by inhalation of a wide variety of antigens to which the individual has been previously sensitized. The pathobiology of the disease is not fully understood, but in addition to the triggers that initiate the disease, host/genetic factors are likely to be important, as only a minority of exposed individuals develop HP. Due to the lack of a diagnostic gold standard, the diagnosis of HP is not straightforward and relies on the integration of a number of factors, including history of exposure, precipitating antibodies to the offending antigen, clinical features, bronchoalveolar lavage, and radiological and pathologic features. However, in the appropriate setting, a high index of suspicion is critically important and may obviate the need for more invasive tests. Clinical presentation and natural history vary widely. Acute forms generally resolve without sequelae, while chronic forms, which are caused by persistent low-grade exposures, are associated with poor prognosis. Corticosteroids may be useful in acute episodes for symptomatic relief or in chronic and progressive disease, but their long-term efficacy has never been validated in prospective clinical trials. Ideally, patients with HP should be referred to centers with expertise, as the overlap with other forms of interstitial lung disease may be substantial. Making the correct diagnosis has critical therapeutic and prognostic implications.

Systemic sclerosis interstitial lung disease evaluation: comparison between semiquantitative and quantitative computed tomography assessments.

The pulmonary fibrosis extent in systemic sclerosis (SSc) has a prognostic value. Chest Computed Tomography (CT) is the gold standard to detect an interstitial lung disease (ILD). Semi-quantitative scores and quantitative methods can estimate the ILD. The first ones have a considerable inter-intraobserver variability, while quantitative scores, based on distribution of lung attenuation parameters (also called CT indexes), can be obtained through expensive and not so user-friendly software. The aim of this work is to investigate whether a DICOM-viewer open-source software (OsiriX) can obtain CT indexes correlating with semi-quantitative scores. Sixty-three chest CTs of ILD-SSc patients were assessed with two semi-quantitative methods (visual extent and limited/extensive ILD grading) and then blindly processed with OsiriX to obtain the distribution parameters of lung attenuation (kurtosis, skewness and mean). Semiquantitative assessment and CT indexes were compared through the Spearman rank test and Mann-Whitney test. All CT indexes showed a statistically significant correlation of moderate degree with the visual extent semi-quantitative assessment (p-value less than 0.05). Skewness was the lung attenuation distribution parameter with the strongest correlation (r =-0.378, p-value = 0.0023). Moreover, CT indexes of patients with an extensive and limited disease were statistically different (p less than 0.01). CT indexes correlating with a radiological semi-quantitative ILD assessment can be obtained through OsiriX. CT indexes can be considered very helpful to discriminate patients with extensive and limited ILD.

Highlights of HRCT imaging in IPF.

High-resolution computed tomography (HRCT) imaging has a central role in the diagnosis of interstitial lung diseases, particularly in the evaluation of patients with suspected idiopathic pulmonary fibrosis (IPF). In approximately half of cases, HRCT scans are sufficient to allow a confident IPF diagnosis. Advances in HRCT scanning and interpretation have facilitated improved accuracy for use in diagnosing IPF, eliminating the need for a surgical biopsy in many patients. HRCT may also have a role to play in predicting the prognosis of the disease;. The role of routine follow-up with HRCT to monitor patients with IPF remains unclear due to lack of sufficient evidence, although, sometimes follow-up HRCT might be necessary to rule out progressive disease in patients with undetermined diagnosis. Advances in the field of HRCT imaging are discussed, along with insights into the clinical utility of this procedure in the diagnosis and management of IPF.

Screening for lung cancer using low-dose spiral CT: 10 years later, state of the art.

Ten years after the first papers on this subject, this editorial represents a brief review on lung cancer screening with low-dose spiral CT. The aim is to present the main theoretical and practical problems related to lung cancer screening, the historical background and results of observational studies and the main ongoing randomised controlled trials. In particular, the National Lung Screening Trial (NLST), which was interrupted early, is discussed. The opinion of the authors is that too many questions are still awaiting an answer.

Magnetic resonance imaging in the complications of kidney transplantation.

Kidney transplantation is currently the treatment of choice in most patients with end-stage chronic renal failure owing to the excellent results in terms of both graft and patient survival. However, surgical complications are still very frequent. Although urological (stricture, urinary fistulas, vesico-ureteral reflux) and lymphatic complications (lymphocoele) have a high incidence, they only rarely lead to graft loss. By contrast, vascular complications (stenosis, arterial and venous thrombosis, arterio-venous fistulas, pseudoaneurysms) are relatively rare, but potentially serious and may affect graft survival. Finally, medical complications such as acute tubular necrosis (ATN), rejection and de novo neoplasms may also arise in kidney transplantation. The purpose of this pictorial review is to illustrate the increasingly significant contribution of magnetic resonance angiography (MRA) in the management of complications of kidney transplantation, and emphasise how this method should now be considered a mandatory step in the diagnostic workup of selected cases. Moreover, the application and role in this setting of new magnetic resonance imaging (MRI) techniques, such as diffusion-weighted and blood oxygen level-dependent (BOLD) MRI, are also discussed.

Clinical standards for diagnosis, treatment and prevention of post-COVID-19 lung disease.

BACKGROUND: The aim of these clinical standards is to provide guidance on 'best practice' care for the diagnosis, treatment and prevention of post-COVID-19 lung disease.METHODS: A panel of international experts representing scientific societies, associations and groups active in post-COVID-19 lung disease was identified; 45 completed a Delphi process. A 5-point Likert scale indicated level of agreement with the draft standards. The final version was approved by consensus (with 100% agreement).RESULTS: Four clinical standards were agreed for patients with a previous history of COVID-19: Standard 1, Patients with sequelae not explained by an alternative diagnosis should be evaluated for possible post-COVID-19 lung disease; Standard 2, Patients with lung function impairment, reduced exercise tolerance, reduced quality of life (QoL) or other relevant signs or ongoing symptoms ≥4 weeks after the onset of first symptoms should be evaluated for treatment and pulmonary rehabilitation (PR); Standard 3, The PR programme should be based on feasibility, effectiveness and cost-effectiveness criteria, organised according to local health services and tailored to an individual patient's needs; and Standard 4, Each patient undergoing and completing PR should be evaluated to determine its effectiveness and have access to a counselling/health education session.CONCLUSION: This is the first consensus-based set of clinical standards for the diagnosis, treatment and prevention of post-COVID-19 lung disease. Our aim is to improve patient care and QoL by guiding clinicians, programme managers and public health officers in planning and implementing a PR programme to manage post-COVID-19 lung disease.

Follow-up in pulmonary sarcoidosis: comparison between HRCT and pulmonary function tests.

PURPOSE: The authors assessed the clinical usefulness of high-resolution computed tomography (HRCT) for monitoring sarcoidosis by comparing changes on HRCT with those on pulmonary function test (PFT) results over time. MATERIALS AND METHODS: The baseline and follow-up (after 13 months, range 15-63 months) HRCT scans of 14 consecutive patients with sarcoidosis were reviewed by a single observer. Each follow-up HRCT examination was assessed as stable, improved (when the extent of HRCT findings was reduced compared with baseline) and worsened (when the extent of HRCT findings was increased and/or when HRCT pattern had become fibrotic compared with baseline). Any increase or decrease in forced vital capacity (FVC)≥10% from baseline was considered significant. Changes on HRCT were then compared with those on FVC. RESULTS: During a median follow-up of 33 (range 15-63) months, HRCT findings worsened in 8/14 (58%) cases, improved in 3/14 (21%) and remained stable in 3/14 (21%). Agreement between changes on HRCT and FVC was moderate (κ=0.49). In 9/14 (64%) cases, HRCT changes were in line with those on FVC. In 4/5 discordant cases, the worsened HRCT findings were not mirrored by FVC changes. CONCLUSIONS: Despite the small size of our study population, our results suggest that HRCT may provide clinicians with additional information about the evolution of sarcoidosis.

Interstitial lung diseases in a lung cancer screening trial.

We assessed the prevalence of interstitial lung disease (ILD) in a cohort of smokers included in a lung cancer screening trial. Two observers independently reviewed, for the presence of findings consistent with ILD, the computed tomography (CT) examinations of 692 heavy smokers recruited by the Multicentric Italian Lung Detection (MILD) trial. Four CT patterns were considered: usual interstitial pneumonia (UIP), other chronic interstitial pneumonia (OCIP), respiratory bronchiolitis (RB) and indeterminate. Subsequently, the evolution of ILD in those subjects who had undergone a repeat CT examination after 3 yrs was assessed. The UIP pattern and the OCIP pattern were identified in two (0.3%) out of 692 and 26 (3.8%) out of 692 patients, respectively; 109 (15.7%) out of 692 patients showed CT abnormalities consistent with RB, while an indeterminate CT pattern was reported in 21 out of 692 (3%) patients. Age, male sex and current smoking status were factors associated with the presence of OCIP and UIP (combined) pattern, although the relationship did not attain statistical significance. A progression of the disease was observed in three (25%) out of 12 subjects with OCIP who underwent repeat CT after 3 yrs. Thin-section CT features of ILD, probably representing smoking-related ILD, are not uncommon in a lung cancer screening population and should not be overlooked.

Benefits of 3D technique in guiding percutaneous retroperitoneal biopsies.

PURPOSE: This study aimed to assess the usefulness and advantages of multiplanar reformations (MPR) during multidetector-row computed tomography (MDCT)-guided percutaneous fine-needle aspiration biopsy (FNAB) and core biopsy of retroperitoneal lesions that are difficult to access with the guidance of ultrasound and axial CT alone owing to overlying bony structures, large vessels or abdominal organs. MATERIALS AND METHODS: MDCT-guided retroperitoneal FNAB and core biopsy was performed on 14 patients with suspected retroperitoneal neoplasm. We used MPR images (sagittal and coronal) obtained with a six-detector-row MDCT scanner and 20-22 gauge Chiba needles. RESULTS: Using MDCT with 3D MPR allowed biological samples to be obtained in all cases (ten cytological and four histological) and diagnostic samples in 11/14 cases (78.5%). Histological samples were deemed adequate for diagnostic assessment in all cases and cytological samples in 7/10 cases (70%). CONCLUSIONS: MPR images allowed sampling of retroperitoneal lesions until now considered unreachable with the guidance of axial MDCT alone. Compared with the conventional procedure, the use of MPR images does not increase the procedure time.

Critical issues in radiology requests and reports.

PURPOSE: This study evaluated the appropriateness and accuracy of 500 radiology requests and their matched reports in order to identify recurring errors in both areas. MATERIALS AND METHODS: A randomly chosen sample consisting of 167 computed tomography (CT), 166 ultrasonography (US) and 167 radiographic examinations were collected and analysed according to national referral guidelines and to the principles of justification and optimisation (Law no. 187/2000). RESULTS: We identified a high rate of inappropriate requests (27.6%) and requests lacking a clinical question (22%). There was good precision in the anamnestic data (80.6%) and in the formulation of the diagnostic question (76.8%). Almost all requests were handwritten, and 12.5% lacked the referring physician's stamp and/or signature. No report mentioned the clinical information received or the equipment used. The use of contrast medium was always reported. Conclusions were reported in 9.8% of these reports. When further investigation would have been necessary, the radiologist omitted to report this in 60% of cases. CONCLUSIONS: Some important weaknesses emerged, especially regarding requests for radiological examinations (22% lacked the clinical question, 27.6% were inappropriate), potentially limiting the effectiveness of the diagnostic process and leading to negative effects on the correct risk management process. There emerges a need for better collaboration between clinicians and radiologists.

Lung function predicts lung cancer risk in smokers: a tool for targeting screening programmes.

The relationship between smoking, lung cancer and airflow obstruction is recognised but it is unclear whether the presence of minimal lung function damage constitutes an independent risk factor for the development of lung cancer. In order to identify those individuals at higher risk of lung cancer on the basis of functional impairment, we evaluated baseline pulmonary function tests of 3,806 heavy smokers undergoing annual chest computed tomography screening, and compared the forced expiratory volume in 1 s (FEV(1)) % predicted of 57 lung cancer cases and that of 3,749 subjects without cancer. We obtained odds ratios (ORs) of lung cancer and the corresponding 95% confidence intervals (CIs) using unconditional logistic regression, adjusting for age, sex, study and smoking variables. Compared with subjects with FEV(1) >or=90% pred, the OR of lung cancer was 2.45 (95% CI 1.39-4.33) for subjects with FEV(1) <90% pred and 2.90 (95% CI 1.34-6.27) for subjects with FEV(1) <70% pred. These data show that even a relatively small reduction in FEV(1) % pred is a significant predictor of increased lung cancer risk. Test screening for lung cancer using airflow obstruction with FEV(1) <90% is a strategy worth future consideration.

High-resolution computed tomography in the diagnosis and follow-up of idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung disease and is associated with a fatal prognosis. Familiarity with the typical appearances of IPF on high-resolution computed tomography (HRCT) is important, as in the appropriate clinical setting, it is often sufficient for establishing a confident diagnosis of IPF without the need for surgical biopsy. Moreover, HRCT can provide important prognostic information in IPF. This is noteworthy, as the course of IPF is variable, and many patients develop complications leading to respiratory failure and death. The purpose of this paper is to review the progress made towards a better understanding of the HRCT patterns of IPF.

Three-dimensional analysis of pulmonary nodules: variability of semiautomated volume measurements between different versions of the same software.

PURPOSE: This study was done to evaluate the variability of semiautomated volume measurements of solid pulmonary nodules between two different versions of the same volumetric software. MATERIALS AND METHODS: The volumes of 100 solid intraparenchymal nodules (mean volume 88.10 mm(3); range 7.36-595.25 mm(3)) studied with the same multidetector computed tomography (MDCT) protocol were determined using two different versions of the same volumetric software (LungCARE 2006G and LungCARE 2007S). The 2006G version is based on a single-segmentation algorithm, whereas the newer version features two algorithms: SmallSizeNodule and AllSizeNodule. The results obtained with the 2006G version were compared with those of the 2007S version with the SmallSizeNodule algorithm, as recommended by the user manual. In addition, we compared the volumetric measurements obtained by the two different algorithms of the 2007S version. RESULTS: The 2006G version and the 2007S version with the SmallSizeNodule algorithm agreed in only two of 100 cases and showed a mean variability of 1.66% (range 0%-8.78%). A more significant volumetric discrepancy was observed between the two different algorithms of the 2007S version, with the AllSizeNodule algorithm providing on average larger volumes (mean variability 71.08%; range 6.02%-218.80%) than SmallSizeNodule. Volume discrepancies were more pronounced in the subgroups of smaller nodules in all comparisons. CONCLUSIONS: There is variability also in the results provided by different versions of the same volumetric software, and this may affect the calculation of the nodule-doubling time. Computer-aided assessment of the growth of lung nodules should always be performed using the same version of volumetric software and the same segmentation algorithm.