Parenchymal Cavitations in Pulmonary Tuberculosis: Comparison between Lung Ultrasound, Chest X-ray and Computed Tomography.

This article aims to detect lung cavitations using lung ultrasound (LUS) in a cohort of patients with pulmonary tuberculosis (TB) and correlate the findings with chest computed tomography (CT) and chest X-ray (CXR) to obtain LUS diagnostic sensitivity. Patients with suspected TB were enrolled after being evaluated with CXR and chest CT. A blinded radiologist performed LUS within 3 days after admission at the Infectious Diseases Department. Finally, 82 patients were enrolled in this study. Bronchoalveolar lavage (BAL) confirmed TB in 58/82 (71%). Chest CT showed pulmonary cavitations in 38/82 (43.6%; 32 TB patients and 6 non-TB ones), LUS in 15/82 (18.3%; 11 TB patients and 4 non-TB ones) and CXR in 27/82 (33%; 23 TB patients and 4 non-TB ones). Twelve patients with multiple cavitations were detected with CT and only one with LUS. LUS sensitivity was 39.5%, specificity 100%, PPV 100% and NPV 65.7%. CXR sensitivity was 68.4% and specificity 97.8%. No false positive cases were found. LUS sensitivity was rather low, as many cavitated consolidations did not reach the pleural surface. Aerated cavitations could be detected with LUS with relative confidence, highlighting a thin air crescent sign towards the pleural surface within a hypoechoic area of consolidation, easily distinguishable from a dynamic or static air bronchogram.

UNet and MobileNet CNN-based model observers for CT protocol optimization: comparative performance evaluation by means of phantom CT images.

Purpose: The aim of this work is the development and characterization of a model observer (MO) based on convolutional neural networks (CNNs), trained to mimic human observers in image evaluation in terms of detection and localization of low-contrast objects in CT scans acquired on a reference phantom. The final goal is automatic image quality evaluation and CT protocol optimization to fulfill the ALARA principle. Approach: Preliminary work was carried out to collect localization confidence ratings of human observers for signal presence/absence from a dataset of 30,000 CT images acquired on a PolyMethyl MethAcrylate phantom containing inserts filled with iodinated contrast media at different concentrations. The collected data were used to generate the labels for the training of the artificial neural networks. We developed and compared two CNN architectures based respectively on Unet and MobileNetV2, specifically adapted to achieve the double tasks of classification and localization. The CNN evaluation was performed by computing the area under localization-ROC curve (LAUC) and accuracy metrics on the test dataset. Results: The mean of absolute percentage error between the LAUC of the human observer and MO was found to be below 5% for the most significative test data subsets. An elevated inter-rater agreement was achieved in terms of S-statistics and other common statistical indices. Conclusions: Very good agreement was measured between the human observer and MO, as well as between the performance of the two algorithms. Therefore, this work is highly supportive of the feasibility of employing CNN-MO combined with a specifically designed phantom for CT protocol optimization programs.

Vascular tree-in-bud sign in Pulmonary Tumour Thrombotic Microangiopathy (PTTM): CT findings for a difficult radiological early antemortem diagnosis.

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Lung vascular changes as biomarkers of severity in systemic sclerosis-associated interstitial lung disease.

OBJECTIVES: It has recently become possible to assess lung vascular and parenchymal changes quantitatively in thoracic CT images using automated software tools. We investigated the vessel parameters of patients with SSc, quantified by CT imaging, and correlated them with interstitial lung disease (ILD) features. METHODS: SSc patients undergoing standard of care pulmonary function testing and CT evaluation were retrospectively evaluated. CT images were analysed for ILD patterns and total pulmonary vascular volume (PVV) extents with Imbio lung texture analysis. Vascular analysis (volumes, numbers and densities of vessels, separating arteries and veins) was performed with an in-house developed software. A threshold of 5% ILD extent was chosen to define the presence of ILD, and commonly used cut-offs of lung function were adopted. RESULTS: A total of 79 patients [52 women, 40 ILD, mean age 56.2 (s.d. 14.2) years, total ILD extent 9.5 (10.7)%, PVV/lung volume % 2.8%] were enrolled. Vascular parameters for total and separated PVV significantly correlated with functional parameters and ILD pattern extents. SSc-associated ILD (SSc-ILD) patients presented with an increased number and volume of arterial vessels, in particular those between 2 and 4 mm of diameter, and with a higher density of arteries and veins of <6 mm in diameter. Considering radiological and functional criteria concomitantly, as well as the descriptive trends from the longitudinal evaluations, the normalized PVVs, vessel numbers and densities increased progressively with the increase/worsening of ILD extent and functional impairment. CONCLUSION: In SSc patients CT vessel parameters increase in parallel with ILD extent and functional impairment, and may represent a biomarker of SSc-ILD severity.

Immune-Checkpoint-Inhibitor-Related Lung Toxicity: A Multicentre Real-Life Retrospective Portrait from Six Italian Centres.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have revolutionized the therapeutic horizons of various cancers. However, immune-related adverse events have been reported, including interstitial lung diseases. Our aim was to describe the clinical and radiological features and survival of a multicentre cohort of patients who developed ICI-related lung toxicity. METHODS: Six Italian centres were involved in the study. Patients who were treated with anti-PD-1/PD-L1 and CTLA-4 mAbs and developed ICI-related lung toxicity were recruited retrospectively to study clinical, radiological, immunological and survival data. RESULTS: A total of 41 patients (25 males, 66.8 ± 9.9 years) were enrolled. Lung toxicity occurred after 204.3 ± 208.3 days of therapy, with ground glass opacities being the most common HRCT pattern (23 cases). Male sex, lung cancer and acute respiratory failure were associated with a shorter latency of toxicity (p = 0.0030, p = 0.0245 and p = 0.0390, respectively). Patients who required high-flow oxygen therapy showed significantly worse survival (p = 0.0028). CONCLUSIONS: Our cohort showed heterogeneous clinical and radiological aspects of ICI-related lung toxicity, with a latency not limited to the first year of treatment. Severity was mainly mild to moderate, although life-threatening events did occur. Our data indicate that strict long-term follow-up is needed to enable early diagnosis and appropriate management.

A practical overview of CT and MRI features of developmental, inflammatory, and neoplastic lesions of the sphenoid body and clivus.

The sphenoid bone is an unpaired bone that contributes to the formation of the skull base. Despite the enormous progress in transnasal endoscopic visualisation, imaging techniques remain the cornerstones to characterise any pathological condition arising in this area. In the present review, we offer a bird's-eye view of the developmental, inflammatory, and neoplastic alterations affecting the sphenoid body and clivus, with the aim to propose a practical diagnostic aid for radiologists based on clinico-epidemiological, computed tomography, and magnetic resonance imaging features.

Low-dose CT for lung cancer screening: position paper from the Italian college of thoracic radiology.

Smoking is the main risk factor for lung cancer (LC), which is the leading cause of cancer-related death worldwide. Independent randomized controlled trials, governmental and inter-governmental task forces, and meta-analyses established that LC screening (LCS) with chest low dose computed tomography (LDCT) decreases the mortality of LC in smokers and former smokers, compared to no-screening, especially in women. Accordingly, several Italian initiatives are offering LCS by LDCT and smoking cessation to about 10,000 high-risk subjects, supported by Private or Public Health Institutions, envisaging a possible population-based screening program. Because LDCT is the backbone of LCS, Italian radiologists with LCS expertise are presenting this position paper that encompasses recommendations for LDCT scan protocol and its reading. Moreover, fundamentals for classification of lung nodules and other findings at LDCT test are detailed along with international guidelines, from the European Society of Thoracic Imaging, the British Thoracic Society, and the American College of Radiology, for their reporting and management in LCS. The Italian College of Thoracic Radiologists produced this document to provide the basics for radiologists who plan to set up or to be involved in LCS, thus fostering homogenous evidence-based approach to the LDCT test over the Italian territory and warrant comparison and analyses throughout National and International practices.

Lung ultrasound (LUS) in pulmonary tuberculosis: correlation with chest CT and X-ray findings.

AIMS: The aim is to describe lung ultrasound (LUS) findings in a cohort of patients with suspected pulmonary tuberculosis (PTB) and compare them with computed tomography (CT) and chest x-ray (CXR) findings in order to evaluate the potentiality of LUS in TB diagnosis. METHODS: In this prospective study, 82 subjects with suspected TB were enrolled after being evaluated with CXR and chest CT. LUS was performed by blinded radiologists within 3 days after admission. A semiquantitative index was used: score 1 (lesions that extend for about 1-15% of the affected zone), score 2 (15-40%) and score 3 (40-100%). RESULTS: Microbiological analysis confirmed TB diagnosis in 58/82 (70.7%). CT was positive in all patients, LUS in 79/82 (96.3%) CXR in 78/82 (95.1%) and adding LUS and CXR in 100%. In PTB patients we found a great number of lungs zones with micronodules and with total findings than non-TPB patients (p < 0.05). Overall LUS sensitivity was 80%, greater for micronodules (82%) and nodules (95%), lower for consolidation with air bronchogram (72%) and cavitations (33%). We reported 5 complicated pleural effusion at LUS, only 1 in CT. CXR overall sensitivity was 81%. Adding CXR and LUS findings we reported a sensitivity of 90%. CONCLUSIONS: LUS could be considered a valid, non-invasive and cost-effective diagnostic tool especially in world regions where CT were not available, also in addiction with CXR. TRIAL REGISTRATION: This study was approved by the Ethics Committee of our University Hospital (rif. CEAVC 14,816).

Clinical implications of microvascular CT scan signs in COVID-19 patients requiring invasive mechanical ventilation.

PURPOSE: COVID-19-related acute respiratory distress syndrome (ARDS) is characterized by the presence of signs of microvascular involvement at the CT scan, such as the vascular tree in bud (TIB) and the vascular enlargement pattern (VEP). Recent evidence suggests that TIB could be associated with an increased duration of invasive mechanical ventilation (IMV) and intensive care unit (ICU) stay. The primary objective of this study was to evaluate whether microvascular involvement signs could have a prognostic significance concerning liberation from IMV. MATERIAL AND METHODS: All the COVID-19 patients requiring IMV admitted to 16 Italian ICUs and having a lung CT scan recorded within 3 days from intubation were enrolled in this secondary analysis. Radiologic, clinical and biochemical data were collected. RESULTS: A total of 139 patients affected by COVID-19 related ARDS were enrolled. After grouping based on TIB or VEP detection, we found no differences in terms of duration of IMV and mortality. Extension of VEP and TIB was significantly correlated with ground-glass opacities (GGOs) and crazy paving pattern extension. A parenchymal extent over 50% of GGO and crazy paving pattern was more frequently observed among non-survivors, while a VEP and TIB extent involving 3 or more lobes was significantly more frequent in non-responders to prone positioning. CONCLUSIONS: The presence of early CT scan signs of microvascular involvement in COVID-19 patients does not appear to be associated with differences in duration of IMV and mortality. However, patients with a high extension of VEP and TIB may have a reduced oxygenation response to prone positioning. TRIAL REGISTRATION: NCT04411459.

CT findings of non-neoplastic central airways diseases.

Non-neoplastic lesions of central airways are uncommon entities with different etiologies, with either focal or diffuse involvement of the tracheobronchial tree. Clinical symptoms of non-neoplastic tracheobronchial diseases are non-specific, and diagnosis is difficult, especially in the early stages. Three-dimensional computed tomography (3D-CT) is an evaluable tool as it allows to assess and characterize tracheobronchial wall lesions and meanwhile it enables the evaluation of airways surrounding structures. Multiplanar reconstructions (MPR), minimum intensity projections (MinIP), and 3D Volume Rendering (VR) (in particular, virtual bronchoscopy) also provide information on the site and of the length of airway alterations. This review will be discussed about (1) primary airway disorders, such as relapsing polychondritis, tracheobronchophathia osteochondroplastica, and tracheobronchomegaly, (2) airway diseases, related to granulomatosis with polyangiitis, Chron's disease, Behcet's disease, sarcoidosis, amyloidosis, infections, intubation and transplantation, (3) tracheobronchial malacia, and (4) acute tracheobronchial injury. 3D-CT findings, especially with MPR and 3D VR reconstructions, allows us to evaluate tracheobronchial disease morphologically in detail.

Moderate-severe coronary calcification predicts long-term cardiovascular death in CT lung cancer screening: The ITALUNG trial.

PURPOSE: Coronary artery calcifications (CAC) are very strong indicators for increased cardio-vascular (CV) risk and can be evaluated also in low-dose computed tomography (LDCT) for lung cancer screening. We assessed whether a simple and fast CAC visual score is associated with CV mortality. METHODS: CAC were retrospectively assessed by two observers using a 4-score (absent, mild, moderate and severe) scale in baseline LDCT obtained in 1364 participants to the ITALUNG trial who had 55-69 years of age and a smoking history ≥20 pack-years. Correlations with CV risk factors at baseline and with CV mortality after 11 years of follow-up were investigated. RESULTS: CAC were absent in 470 (34.5%), mild in 433 (31.7%), moderate in 357 (26.2%) and severe in 104 (7.6%) subjects. CAC severity correlated (≤0.001) with age, male sex, pack-years, history of arterial hypertension or diabetes, obesity and treated hypercholesterolemia. Twenty-one CV deaths occurred. Moderate or severe CAC were significantly associated with higher CV mortality after adjustment for all other known risk factors (ARR = 2.72; 95 %CI:1.04-7.11). Notably, also in subjects with none or one only additional CV risk factor, the presence of moderate-severe CAC allowed to identify a subgroup of subjects with higher CV death risk (RR = 3.66; CI95%:1.06-12.6). CONCLUSIONS: Moderate or severe CAC visually assessed in LDCT examinations for lung cancer screening are independently associated with CV mortality.

The incremental value of computed tomography of COVID-19 pneumonia in predicting ICU admission.

Triage is crucial for patient's management and estimation of the required intensive care unit (ICU) beds is fundamental for health systems during the COVID-19 pandemic. We assessed whether chest computed tomography (CT) of COVID-19 pneumonia has an incremental role in predicting patient's admission to ICU. We performed volumetric and texture analysis of the areas of the affected lung in CT of 115 outpatients with COVID-19 infection presenting to the emergency room with dyspnea and unresponsive hypoxyemia. Admission blood laboratory including lymphocyte count, serum lactate dehydrogenase, D-dimer and C-reactive protein and the ratio between the arterial partial pressure of oxygen and inspired oxygen were collected. By calculating the areas under the receiver-operating characteristic curves (AUC), we compared the performance of blood laboratory-arterial gas analyses features alone and combined with the CT features in two hybrid models (Hybrid radiological and Hybrid radiomics)for predicting ICU admission. Following a machine learning approach, 63 patients were allocated to the training and 52 to the validation set. Twenty-nine (25%) of patients were admitted to ICU. The Hybrid radiological model comprising the lung %consolidation performed significantly (p = 0.04) better in predicting ICU admission in the validation (AUC = 0.82; 95% confidence interval 0.73-0.97) set than the blood laboratory-arterial gas analyses features alone (AUC = 0.71; 95% confidence interval 0.56-0.86). A risk calculator for ICU admission was derived and is available at: https://github.com/cgplab/covidapp . The volume of the consolidated lung in CT of patients with COVID-19 pneumonia has a mild but significant incremental value in predicting ICU admission.

Prognostic value of CT pulmonary angiography parameters in acute pulmonary embolism.

OBJECTIVES: Computed tomographic pulmonary angiography (CTPA) is the first-line test in acute pulmonary embolism (APE) diagnostic algorithm, but its correlation with short-term outcome remains not clear at all. The aim is to determine whether CTPA findings can predict 30-day mortality of patients with APE in Emergency Department. METHODS: This retrospective monocentric study involved 780 patients with APE diagnosed at the Emergency Department of our institution (period 2010-2019). These CTPA findings were evaluated: embolic obstruction burden score (Qanadli score), common pulmonary artery trunk diameter, right-to-left ventricular ratio, azygos vein and coronary sinus diameters. Comorbidities and fatal/nonfatal adverse outcomes within 30 days were recorded. Troponin I values were correlated with angiographic parameters with multiple logistic regression analysis. RESULTS: The all-cause and APE-related 30-day mortality rates were 5.9% and 3.6%, respectively. Patients who died within 30 days were older with higher prevalence rates of malignancy. Qanadli score and all CTPA parameters correlate with Troponin I level and the presence of RVD at echocardiography (p values < 0.0001). Instead, RV/LV ratio and coronary sinus diameter correlate with 30-day mortality (p values < 0.05). At the multivariate logistic regression analysis, only coronary sinus and RVD remained significant with an HR = 2.5 (95% CI 1.1-5.6) and HR = 1.9 (95% CI 0.95-3.7), respectively. CONCLUSION: CTPA quantification of right ventricular strain is an accurate predictor of 30-day mortality. In particular, it seems that a dilated coronary sinus (>9 mm) has an additional prognostic value in association with echocardiographic signs of right-heart disfunction and high Troponin I levels.

Exogenous lipoid pneumonia: when radiologist makes the difference.

PURPOSE: To report high-resolution CT (HRCT) findings in our group of patients with exogenous lipoid pneumonia (ELP), confirmed with histopathological findings and clinical-anamnestic data, in order to describe the most common radiological patterns of this rare disorder. MATERIALS AND METHODS: In this retrospective study, HRCT of 10 patients with ELP were evaluated by three radiologists. Diagnosis of ELP was made through CT, bronchiolo-alveolar lavage (BAL) and a pneumological examination associated with an accurate medical anamnesis. Five patients had a histologically proven ELP, through lung biopsy. All patients had a chronic exposition to substances made of animal fat or mineral/vegetable oils. RESULTS: In our cohort of patients with ELP, the following parenchymal patterns were observed: 8/10 patients had lung consolidation with adipose density (attenuation values < - 40 HU); 10/10 patients had multiple areas of ground glass opacity; 6/10 patients had smooth thickening of interlobular septa and ground glass opacities ("crazy-paving" pattern); 2/10 patients presented nodules > 2.5 cm with spiculated margins (tumor-like); 5/10 patients showed reactive lymph nodes enlargement. The oldest lesions were characterized by bronchiectasis and fibrosis around the lipidic consolidations. CONCLUSION: Pulmonary alterations found in HRCT exams can be confused with other lung diseases (especially lung tumors) and they are always a challenge even for the most experienced radiologist. In our experience, although non-specific, consolidation areas with low HU values and crazy-paving pattern are frequently associated in ELP. These characteristics should alert the radiologist to consider ELP among the possible differential diagnoses, always correlating the results of CT examination with appropriate clinical-laboratory evaluations and an accurate anamnesis.

Evaluation of diaphragm thickening by diaphragm ultrasonography: a reproducibility and a repeatability study.

PURPOSE: We have focused on the two-dimensional (B-mode) and the time-motion (M-mode) analysis of the zone of apposition to determine the reliability of diaphragm ultrasonography in the clinical environment. METHODS: Ten healthy volunteers were enrolled and studied by three operators with different skills in ultrasonography. For every volunteer, each operator acquired three images of the diaphragm for each side, both in B-mode and in M-mode. Then a fourth operator calculated the thickening fraction (TF), by means of the formula TF = (TEI - TEE)/TEE (TEI is the thickness at end inspiration and TEE the thickness at end expiration). Afterwards, intraclass correlation coefficients (ICCs) were computed on TF to establish reproducibility and repeatability both in the B- and M-modes. A Coefficient of Repeatability or repeatability (CR) ≤ 0.3 was considered acceptable. RESULTS: Both B-mode (CRs 0.16-0.26) and M-mode (CRs 0.10-0.15) were sufficiently repeatable to assess TF, except for the less experienced operator (CRs B-Mode 0.20-0.32). Reproducibility was moderate to good between operators with CRs much narrower for the M-Mode (0.13-0.14). CONCLUSIONS: The results of our study have shown that diaphragm ultrasound is repeatable and reproducible when carried out by a radiologist or an intensivist with a basic curriculum in ultrasonography. The method is more accurate when using the M-mode for less experienced operators, and in this case, repeatability and reproducibility are not sufficient to make clinical decisions. No TF value lower than 36% was obtained using both techniques. This suggests the existence of a cut-off value that could be used as an initial tool to discriminate healthy subjects from those affected by diaphragmatic dysfunction. CLINICAL TRIAL REGISTRATION: EUDRACT 2015-004635-12.

Quantitative analysis of pulmonary vasculature in systemic sclerosis at spirometry-gated chest CT.

OBJECTIVE: To prospectively investigate whether differences in pulmonary vasculature exist in systemic sclerosis (SSc) and how they are distributed in patients with different pulmonary function. METHODS: Seventy-four patients with SSc undergoing chest CT scan for interstitial lung disease (ILD) screening or follow-up were prospectively enrolled. A thorough clinical, laboratory and functional evaluation was performed the same day. Chest CT was spirometry gated at total lung capacity and images were analysed by two automated software programs to quantify emphysema, ILD patterns (ground-glass, reticular, honeycombing), and pulmonary vascular volume (PVV). Patients were divided in restricted (FVC% <80, DLco%<80), isolated DLco% reduction (iDLco- FVC%≥80, DLco%<80) and normals (FVC%≥80, DLco%≥80). Spearman ρ, Mann-Whitney tests and logistic regressions were used to assess for correlations, differences among groups and relationships between continuous variables. RESULTS: Absolute and lung volume normalised PVV (PVV/LV) correlated inversely with functional parameters and positively with all ILD patterns (ρ=0.75 with ground glass, ρ=0.68 with reticular). PVV/LV was the only predictor of DLco at multivariate analysis (p=0.007). Meanwhile, the reticular pattern prevailed in peripheral regions and lower lung thirds, PVV/LV prevailed in central regions and middle lung thirds. iDLco group had a significantly higher PVV/LV (2.2%) than normal (1.6%), but lower than restricted ones (3.8%). CONCLUSIONS: Chest CT in SSc detects a progressive increase in PVV/LV as DLco decreases. Redistribution of perfusion to less affected lung regions rather than angiogenesis nearby fibrotic lung may explain the results. Further studies to ascertain whether the increase in PVV/LV reflects a real increase in blood volume are needed.

Decreased cardiovascular mortality in the ITALUNG lung cancer screening trial: Analysis of underlying factors.

OBJECTIVES: In the ITALUNG lung cancer screening trial after 9.3 years of follow-up we observed an unexpected significant decrease of cardiovascular (CV) mortality in subjects invited for low-dose CT (LDCT) screening as compared to controls undergoing usual care. Herein we extended the mortality follow-up and analyzed the potential factors underlying such a decrease. MATERIALS AND METHODS: The following factors were assessed in screenes and controls: burden of CV disease at baseline, changes in smoking habits, use of CV drugs and frequency of planned vascular procedures after randomisation. Moreover, in the screenes we evaluated inclusion of presence of coronary artery calcification (CAC) in the LDCT report form that was transmitted to the participant and his/her General Practitioner. RESULTS: The 2-years extension of follow-up confirmed a significant decrease of CV mortality in the subjects of the active group compared to control subjects (15.6 vs 34.0 per 10,000; p = 0.001) that was not observed in the drops-out of the active group. None of the explaining factors we considered significantly differed between active and control group. However, the subjects of the active group with reported CAC experienced a not significantly lower CV mortality and showed a significantly higher use of CV drugs and frequency of planned vascular procedures than the control group. CONCLUSIONS: LDCT screening for lung cancer offers the opportunity for detection of CAC that is an important CV risk factor. Although the underlying mechanisms are not clear, our results suggest that the inclusion of information about CAC presence in the LDCT report may represent a candidate factor to explain the decreased CV mortality observed in screened subjects of the ITALUNG trial, possibly resulting in intervention for patient care to prevent CV deaths. Further studies investigating whether prospective reporting and rating of CAC have independent impact on such interventions and CV mortality are worthy.

Lung Cancer in Patients with Severe Idiopathic Pulmonary Fibrosis: Critical Aspects.

Idiopathic pulmonary fibrosis (IPF) is a rare interstitial lung disease limited to the lung with an undefined etiopathogenesis and a very short life expectancy (less than 5 years). IPF susceptibility has been associated with several genetic and environmental risk factors and the prognosis is conditioned by comorbidities such as gastro-esophageal reflux, depression, venous thromboembolism, pulmonary hypertension and lung cancer. At 5 years follow-up, 15% of IPF patients develop lung cancer, which can significantly reduce their survival. Because diagnostic or therapeutic procedures such as surgical, radiation or pharmacological treatments may induce acute exacerbations and increase mortality, the management of lung cancer in IPF patients is a very difficult task. This study discusses advantages and disadvantages of lung cancer treatments in patients with severe IPF, highlighting several controversial aspects on this topic, including potential nintedanib treatment.

Diagnostic accuracy of lung ultrasonography combined with procalcitonin for the diagnosis of pneumonia: a pilot study.

BACKGROUND: The diagnostic value of lung ultrasonography (LUS) and procalcitonin (PCT) in the diagnosis of lung infections is known. No studies evaluated the combination of LUS and PCT for the diagnosis of pneumonia in the emergency department (ED). We evaluated the diagnostic accuracy of the combination of LUS and PCT in the diagnosis of pneumonia. METHODS: Patients with respiratory symptoms of unexplained origin who underwent a chest CT in ED were included in the study if PCT assay was available. LUS was performed before CT and was targeted to the detection of lung consolidations with the morphologic features of pneumonia. A PCT assay was performed at presentation, and cut-off of 0.25 and of 0.5 ng/ml were used to rule-out and rule-in pneumonia. The final diagnosis of pneumonia was established by independent clinicians, on the basis of clinical chart review including CT results. RESULTS: We enrolled 128 patients and pneumonia was the final diagnosis in 61 (47.7%). In 38 patients (29.7%) LUS and PCT were negative (PCT < 0.25 ng/ml). The overall accuracy, sensitivity and negative predictive value of LUS/PCT were 88.8, 96.7 and 94.7% respectively. Sensitivity of the LUS/PCT test was significantly superior to LUS alone (85.2%) and PCT alone (73.8%) (p < 0.05 for both). Specificity and positive predictive value of the combination of positivity of LUS/PCT (PCT > 0.5 ng/ml) were 94% and 83.3% respectively. Specificity of LUS/PCT was not significantly different to LUS alone (88.1%) (p = 0.125). CONCLUSIONS: The sensitivity of the combination of LUS with PCT for the diagnosis of pneumonia was significantly superior when compared with the sensitivity of LUS and PCT alone.