Chest Computed Tomography Studies Research Articles

Redefining Radiation Metrics: Evaluating Actual Doses in Computed Tomography Scans.

Computed tomography (CT) contributes significantly to the collective dose from medical sources, raising concerns about potential health risks. However, existing radiation dose estimation tools, such as volume computed tomography dose index (CTDIvol), dose-length product (DLP), effective dose (ED), and size-specific dose estimate (SSDE), have limitations in accurately reflecting patient exposure. This study introduces a new parameter, size-specific dose-length product (DLPss), aiming to enhance the precision of radiation dose estimation in real-life scenarios. A retrospective analysis of 134 chest CT studies was conducted. Relationships between CTDIvol and anthropometric parameters were examined, and SSDE was calculated based on effective diameter. Additionally, the novel parameter, DLPss, was introduced, considering scan length and cross-sectional dimensions. Analysis reveals variations in scan length, effective diameter, and CTDIvol between genders. Strong correlations were observed between CTDIvol and effective diameter, particularly in men. The average CTDIvol for the entire group was 7.83 ± 2.92 mGy, with statistically significant differences between women (7.38 ± 3.23 mGy) and men (8.30 ± 2.49 mGy). SSDE values showed significant gender differences, with men exhibiting higher values. The average SSDE values for women and men were 9.15 ± 2.5 mGy and 9.6 ± 2.09 mGy, respectively, with a statistically significant difference (p = 0.03). The newly introduced DLPss values ranged around 343.90 ± 81.66 mGy·cm for the entire group, with statistically significant differences between women (323.53 ± 78.69 mGy·cm) and men (364.89 ± 79.87 mGy·cm) (p < 0.05), providing a comprehensive assessment of total radiation dose. The study highlights the need for accurate radiation dose estimation, emphasizing the impact of CT examination parameters on dose variability. The proposed DLPss parameter offers a promising approach to enhancing precision in assessing radiation risk during CT scans. Further research is warranted to explore additional parameters for a comprehensive understanding of radiation exposure and to optimize imaging protocols for patient safety.

Persistent hiccups as a rare presenting symptom of empyema: a case report

BackgroundEmpyema is uncommon owing to antibiotic use but still affects patient health if not treated. Hiccups as the initial symptom of empyema are rare; however, empyema should be considered if a patient has persistent hiccups with unexplained fever.Case presentationWe present a case of persistent hiccups, left upper quadrant abdominal pain, and fever on day 1, and total left lung white-out and empyema on day 3. The hiccups resolved gradually after antibiotic treatment and surgical decortication.ConclusionsClinicians should consider the possibility of empyema and conduct a chest computed tomography study if unexplained fever and persistent hiccups coexist.

Chest Computed Tomography Characteristics of Critically Ill COVID-19 Patients with Auto-antibodies Against Type I Interferons

PurposePatients with auto-antibodies neutralizing type I interferons (anti-IFN auto-Abs) are at risk of severe forms of coronavirus disease 19 (COVID-19). The chest computed tomography (CT) scan characteristics of critically ill COVID-19 patients harboring these auto-Abs have never been reported.MethodsBicentric ancillary study of the ANTICOV study (observational prospective cohort of severe COVID-19 patients admitted to the intensive care unit (ICU) for hypoxemic acute respiratory failure between March 2020 and May 2021) on chest CT scan characteristics (severity score, parenchymal, pleural, vascular patterns). Anti-IFN auto-Abs were detected using a luciferase neutralization reporting assay. Imaging data were collected through independent blinded reading of two thoracic radiologists of chest CT studies performed at ICU admission (± 72 h). The primary outcome measure was the evaluation of severity by the total severity score (TSS) and the CT severity score (CTSS) according to the presence or absence of anti-IFN auto-Abs.ResultsTwo hundred thirty-one critically ill COVID-19 patients were included in the study (mean age 59.5 ± 12.7 years; males 74.6%). Day 90 mortality was 29.5% (n = 72/244). There was a trend towards more severe radiological lesions in patients with anti-IFN auto-Abs than in others, not reaching statistical significance (median CTSS 27.5 (21.0–34.8) versus 24.0 (19.0–30.0), p = 0.052; median TSS 14.5 (10.2–17.0) versus 12.0 (9.0–15.0), p = 0.070). The extra-parenchymal evaluation found no difference in the proportion of patients with pleural effusion, mediastinal lymphadenopathy, or thymal abnormalities in the two populations. The prevalence of pulmonary embolism was not significantly different between groups (8.7% versus 5.3%, p = 0.623, n = 175).ConclusionThere was no significant difference in disease severity as evaluated by chest CT in severe COVID-19 patients admitted to the ICU for hypoxemic acute respiratory failure with or without anti-IFN auto-Abs.

Reporting of coronary artery calcification on chest CT studies in patients with interstitial lung disease

To evaluate the prevalence of coronary artery calcification (CAC) on non-contrast computed tomography (CT) of the thorax in patients with interstitial lung disease (ILD), assess consistency of CAC reporting and assess incidence of subsequent cardiac events. Patients with known interstitial lung disease who underwent a CT thorax over a 2-year period were retrospectively reviewed. Presence of CAC was assessed using a visual scale for CAC reporting and graded as mild, moderate, or severe by two cardiothoracic radiologists. CT reports were reviewed to determine if presence of CAC had been described. Electronic medical records were reviewed for any subsequent cardiothoracic events from the date of the CT thorax to present. 254 patients were included in the analysis (54.7% men; mean age 59.9 yo). 43.7% had CAC on their CT thorax; however, in 87.3% of those, reports did not comment on its presence. 8 patients had cardiac events; 7 of them had CAC on CT although only in 1 case this was reported. Global CAC and LAD CAC Patients with cardiac events had a significantly higher global CAC (p=0.016) and LAD CAC (p=0.048) when compared to patients without. We demonstrated a high prevalence of CAC in ILD patients and its significant association with adverse cardiac events. Unfortunately, CAC on CT thorax is still largely unreported. As per recent BSCI/BSCCT and BSTI guidelines, reporting of CAC should become part of routine practice, as may prompt prevention and impact on patients outcome.

Photon-counting detector CT allows significant reduction in radiation dose while maintaining image quality and noise on non-contrast chest CT

PurposeTo investigate if clinical non-contrast chest CT studies obtained with PCD CT using much lower radiation exposure can achieve the same image quality as with the currently established EID protocol. Materials/methodsA total of seventy-one patients were identified who had a non-contrast chest computed tomography (CT) done on PCD CT and EID CT scanners within a 4-month interval. Five fellowship trained chest radiologists, blinded to the scanner details were asked to review the cases side-by-side and record their preference for images from either the photon-counting-detector (PCD) CT or the energy-integrating detector (EID) CT scanner. ResultsThe median CTDIvol for PCD-CT system was 4.710 mGy and EID system was 7.80 mGy (p < 0.001). The median DLP with the PCD-CT was 182.0 mGy.cm and EID system was 262.60 mGy.cm (p < 0.001). The contrast to noise ratio (CNR) was superior on the PCD-CT system 59.2 compared to the EID-CT 53.3; (p < 0.001). Kappa-statistic showed that there was poor agreement between the readers over the image quality from the PCD and EID scanners (κ = 0.19; 95 % CI: 0.12 – 0.27; p < 0.001). Chi-square analysis revealed that 3 out of 5 readers showed a significant preference for images from the PCDCT (p ≤ 0.012). There was no significant difference in the preferences of two readers between EID-CT and PCD-CT images. ConclusionThe first clinical PCD-CT system allows a significant reduction in radiation exposure while maintaining image quality and image noise using a standardized non-contrast chest CT protocol.

Fatal Infections Differentially Involve Allograft and Native Lungs in Single Lung Transplant Recipients.

Respiratory infections complicate lung transplantation and increase the risk of allograft dysfunction. Allograft lungs may have different susceptibilities to infection than native lungs, potentially leading to different disease severity in lungs of single lung transplant recipients (SLTRs). To study whether infections affect allograft and native lungs differently in SLTRs but similarly in double LTRs (DLTRs). Using an institutional database of LTRs, medical records were searched, chest computed tomography studies were systematically reviewed, and histopathologic features were recorded per lung lobe and graded semiquantitatively. A multilobar-histopathology score (MLHS) including histopathologic data from each lung and a bilateral ratio (MLHSratio) comparing histopathologies between both lungs were calculated in SLTRs and compared to DLTRs. Six SLTRs died of infection involving the lungs. All allografts showed multifocal histopathologic evidence of infection, but at least 1 lobe of the native lung was uninvolved. In 4 of 5 DLTRs, histopathologic evidence of infection was seen in all lung lobes. On computed tomography, multifocal ground-glass and/or nodular opacities were found in a bilateral distribution in all DLTRs but in only 2 of 6 SLTRs. In SLTRs, the MLHSAllograft was higher than MLHSNative (P = .02). The MLHSratio values of SLTR and DLTR were significantly different (P < .001). Allograft and native lungs appear to harbor different susceptibilities to infections. The results are important for the management of LTRs.

Existing Nongated CT Coronary Calcium Predicts Operative Risk in Patients Undergoing Noncardiac Surgeries (ENCORES).

Preoperative cardiovascular risk stratification before noncardiac surgery is a common clinical challenge. Coronary artery calcium scores from ECG-gated chest computed tomography (CT) imaging are associated with perioperative events. At the time of preoperative evaluation, many patients will not have had ECG-gated CT imaging, but will have had nongated chest CT studies performed for a variety of noncardiac indications. We evaluated relationships between coronary calcium severity estimated from previous nongated chest CT imaging and perioperative major clinical events (MCE) after noncardiac surgery. We retrospectively identified consecutive adults age ≥45 years who underwent in-hospital, major noncardiac surgery from 2016 to 2020 at a large academic health system composed of 4 acute care centers. All patients had nongated (contrast or noncontrast) chest CT imaging performed within 1 year before surgery. Coronary calcium in each vessel was retrospectively graded from absent to severe using a 0 to 3 scale (absent, mild, moderate, severe) by physicians blinded to clinical data. The estimated coronary calcium burden (ECCB) was computed as the sum of scores for each coronary artery (0 to 9 scale). A Revised Cardiac Risk Index was calculated for each patient. Perioperative MCE was defined as all-cause death or myocardial infarction within 30 days of surgery. A total of 2554 patients (median age, 68 years; 49.7% women; median Revised Cardiac Risk Index, 1) were included. The median time interval from nongated chest CT imaging to noncardiac surgery was 15 days (interquartile range, 3-106 days). The median ECCB was 1 (interquartile range, 0-3). Perioperative MCE occurred in 136 (5.2%) patients. Higher ECCB values were associated with stepwise increases in perioperative MCE (0: 2.9%, 1-2: 3.7%, 3-5: 8.0%; 6-9: 12.6%, P<0.001). Addition of ECCB to a model with the Revised Cardiac Risk Index improved the C-statistic for MCE (from 0.675 to 0.712, P=0.018), with a net reclassification improvement of 0.428 (95% CI, 0.254-0.601, P<0.0001). An ECCB ≥3 was associated with 2-fold higher adjusted odds of MCE versus an ECCB <3 (adjusted odds ratio, 2.11 [95% CI, 1.42-3.12]). Prevalence and severity of coronary calcium obtained from existing nongated chest CT imaging improve preoperative clinical risk stratification before noncardiac surgery.

A Retrospective Chart Review of Pediatric Complicated Community-Acquired Pneumonia: An Experience in the Al Qassimi Women and Children Hospital.

Background Community-acquired pneumonia (CAP) is one of the most common global health issues. Even though many vaccinations and new diagnostic tools are available, CAP has a higher mortality rate, especially in children less than five years of age. Complicated CAP (CCAP) in a healthy child is a severe disease characterized by a combination of local complications, such as parapneumonic effusion (PPE), empyema (EMP), necrotizing pneumonia (NP), abscess, pneumothorax, and bronchopleural fistula, and systemic complications, such as bacteremia, metastatic infection, multiorgan failure, acute respiratory distress syndrome, disseminated intravascular coagulation, and, rarely, death. This study describes the demographic features, clinical presentation, management, and outcomes of patients diagnosed with CCAP at the Al Qassimi Women's and Children's Hospital (AQWCH). Methodology This retrospective chart review aims to collect and explore the data of all previously healthy children admitted with CCAP between the ages of one month and 13 years at AQWCH from January 2018 to December 2020. The primary study outcome measure is to provide clinicians with the diagnostics, evaluation, and management required to treat complicated pneumonia. Results A total of 195 patients were diagnosed with CAP, of whom 30 (15.3%) were diagnosed with CCAP. Of these, 14 (46.6%) patients had NP, eight (26.7%) had PPE, and eight (26.7%) had EMP. The median age of patients was 2.5 years, with 13 (43%) males and 17 (57%) females. The median duration of their stay in the hospital was 16 days. All patients were vaccinated with Hib, PCV13, or PCV7, and 57% of the patients received antibiotics before admission. The most common findings were consolidation and pleural effusion. Blood culture was negative in all cases, and pleural culture was positive only in three cases. A total of 17 (57%) patients underwent video-assisted thoracoscopic surgery (VATS), and post-VATS surgical emphysema was found to be the most common complication. Chest X-rays normalized after three months in 65% of patients. On comparing patients who were admitted to the Pediatric Intensive Care Unit (PICU) before any surgical intervention with those who were not, it was found that patients who required PICU admission were young (median = 2 years; interquartile range (IQR) = 1-4.5; p = 0.044) and had higher respiratory rate (mean = 49 breaths/per minute, standard deviation (SD) = 11; p = 0.000). In addition, they had lower median albumin (median = 2 g/L; IQR = 1.8-2.23; p = 0.004). On comparing patients who required VATS and those who did not require VATS, it was found that the former had a higher median respiratory rate (48 per min; range = 42-54; p = 0.01). A cavity in the chest computed tomography (CT) was found in 86% of patients with VATS (p = 0.017), and they had lower median albumin (median = 2 g/L; IQR = 1.92-2.24; p = 0.012), as well as longer median duration of using oral antibiotics (median = 21 days; IQR = 19-26; p = 0.025). Patients with complicated NP had a higher respiratory rate and higher PICU admission, and more cavity in the chest was found in the CT study. Most NP patients also underwent VATS and had longer median days of using oral antibiotics. One patient developed a bronchopleural fistula, and one patient diagnosed with NP died. Conclusions CCAP is a major cause of hospitalization in children. It is important to suspect CCAP in all CAP patients not responding to treatment after 48-72 hours.

Imaging manifestations of pulmonary melioidosis: A case series

Melioidosis is an endemic disease in Southeast Asia and Oceania caused by the gram-negative bacillus Burkholderia pseudomallei. We studied 15 adult patients from Colombia with microbiologically diagnosed pulmonary melioidosis. We reviewed 15 chest X-rays and 10 chest computed tomography (CT) studies. Of the 15 patients, 87% met the criteria for acute infection and 13% met the criteria for chronic infection. The most common findings on chest X-rays were consolidation (86%), nodules (26%), and cavitation (20%). On CT studies, consolidation and nodules were observed in 90% of cases; the areas of consolidation were predominantly located in the basal and central zones in 60%. Areas of cavitation were observed in 50%, pleural effusion in 60%, and mediastinal lymph nodes in 30%. In patients with acute pulmonary melioidosis (n=8), the findings observed were nodules (100%), mixed pattern with nodules and consolidation (87%), pleural effusion (88%), and mediastinal lymph nodes (25%). The two patients with chronic pulmonary melioidosis both had cavitation. Acute lung infection with B. Pseudomallei has radiologic manifestations similar to those of pneumonia due to other causes. In areas where the disease is endemic, it is essential to include acute melioidosis in the differential diagnosis of pulmonary nodules and chronic melioidosis in the differential diagnosis of cavitated chronic lung lesions.

Imaging the acute respiratory distress syndrome: past, present and future.

In patients with the acute respiratory distress syndrome (ARDS), lung imaging is a fundamental tool in the study of the morphological and mechanistic features of the lungs. Chest computed tomography studies led to major advances in the understanding of ARDS physiology. They allowed the in vivo study of the syndrome’s lung features in relation with its impact on respiratory physiology and physiology, but also explored the lungs’ response to mechanical ventilation, be it alveolar recruitment or ventilator-induced lung injuries. Coupled with positron emission tomography, morphological findings were put in relation with ventilation, perfusion or acute lung inflammation. Lung imaging has always been central in the care of patients with ARDS, with modern point-of-care tools such as electrical impedance tomography or lung ultrasounds guiding clinical reasoning beyond macro-respiratory mechanics. Finally, artificial intelligence and machine learning now assist imaging post-processing software, which allows real-time analysis of quantitative parameters that describe the syndrome’s complexity. This narrative review aims to draw a didactic and comprehensive picture of how modern imaging techniques improved our understanding of the syndrome, and have the potential to help the clinician guide ventilatory treatment and refine patient prognostication.

Imaging Severity COVID-19 Assessment in Vaccinated and Unvaccinated Patients: Comparison of the Different Variants in a High Volume Italian Reference Center.

Purpose: To analyze the vaccine effect by comparing five groups: unvaccinated patients with Alpha variant, unvaccinated patients with Delta variant, vaccinated patients with Delta variant, unvaccinated patients with Omicron variant, and vaccinated patients with Omicron variant, assessing the “gravity” of COVID-19 pulmonary involvement, based on CT findings in critically ill patients admitted to Intensive Care Unit (ICU). Methods: Patients were selected by ICU database considering the period from December 2021 to 23 March 2022, according to the following inclusion criteria: patients with proven Omicron variant COVID-19 infection with known COVID-19 vaccination with at least two doses and with chest Computed Tomography (CT) study during ICU hospitalization. Wee also evaluated the ICU database considering the period from March 2020 to December 2021, to select unvaccinated consecutive patients with Alpha variant, subjected to CT study, consecutive unvaccinated and vaccinated patients with Delta variant, subjected to CT study, and, consecutive unvaccinated patients with Omicron variant, subjected to CT study. CT images were evaluated qualitatively using a severity score scale of 5 levels (none involvement, mild: ≤25% of involvement, moderate: 26–50% of involvement, severe: 51–75% of involvement, and critical involvement: 76–100%) and quantitatively, using the Philips IntelliSpace Portal clinical application CT COPD computer tool. For each patient the lung volumetry was performed identifying the percentage value of aerated residual lung volume. Non-parametric tests for continuous and categorical variables were performed to assess statistically significant differences among groups. Results: The patient study group was composed of 13 vaccinated patients affected by the Omicron variant (Omicron V). As control groups we identified: 20 unvaccinated patients with Alpha variant (Alpha NV); 20 unvaccinated patients with Delta variant (Delta NV); 18 vaccinated patients with Delta variant (Delta V); and 20 unvaccinated patients affected by the Omicron variant (Omicron NV). No differences between the groups under examination were found (p value > 0.05 at Chi square test) in terms of risk factors (age, cardiovascular diseases, diabetes, immunosuppression, chronic kidney, cardiac, pulmonary, neurologic, and liver disease, etc.). A different median value of aerated residual lung volume was observed in the Delta variant groups: median value of aerated residual lung volume was 46.70% in unvaccinated patients compared to 67.10% in vaccinated patients. In addition, in patients with Delta variant every other extracted volume by automatic tool showed a statistically significant difference between vaccinated and unvaccinated group. Statistically significant differences were observed for each extracted volume by automatic tool between unvaccinated patients affected by Alpha variant and vaccinated patients affected by Delta variant of COVID-19. Good statistically significant correlations among volumes extracted by automatic tool for each lung lobe and overall radiological severity score were obtained (ICC range 0.71–0.86). GGO was the main sign of COVID-19 lesions on CT images found in 87 of the 91 (95.6%) patients. No statistically significant differences were observed in CT findings (ground glass opacities (GGO), consolidation or crazy paving sign) among patient groups. Conclusion: In our study, we showed that in critically ill patients no difference were observed in terms of severity of disease or exitus, between unvaccinated and vaccinated patients. The only statistically significant differences were observed, with regard to the severity of COVID-19 pulmonary parenchymal involvement, between unvaccinated patients affected by Alpha variant and vaccinated patients affected by Delta variant, and between unvaccinated patients with Delta variant and vaccinated patients with Delta variant.

Artificial Intelligence and COVID-19 Using Chest CT Scan and Chest X-ray Images: Machine Learning and Deep Learning Approaches for Diagnosis and Treatment.

Objective: To report an overview and update on Artificial Intelligence (AI) and COVID-19 using chest Computed Tomography (CT) scan and chest X-ray images (CXR). Machine Learning and Deep Learning Approaches for Diagnosis and Treatment were identified. Methods: Several electronic datasets were analyzed. The search covered the years from January 2019 to June 2021. The inclusion criteria were studied evaluating the use of AI methods in COVID-19 disease reporting performance results in terms of accuracy or precision or area under Receiver Operating Characteristic (ROC) curve (AUC). Results: Twenty-two studies met the inclusion criteria: 13 papers were based on AI in CXR and 10 based on AI in CT. The summarized mean value of the accuracy and precision of CXR in COVID-19 disease were 93.7% ± 10.0% of standard deviation (range 68.4–99.9%) and 95.7% ± 7.1% of standard deviation (range 83.0–100.0%), respectively. The summarized mean value of the accuracy and specificity of CT in COVID-19 disease were 89.1% ± 7.3% of standard deviation (range 78.0–99.9%) and 94.5 ± 6.4% of standard deviation (range 86.0–100.0%), respectively. No statistically significant difference in summarized accuracy mean value between CXR and CT was observed using the Chi square test (p value > 0.05). Conclusions: Summarized accuracy of the selected papers is high but there was an important variability; however, less in CT studies compared to CXR studies. Nonetheless, AI approaches could be used in the identification of disease clusters, monitoring of cases, prediction of the future outbreaks, mortality risk, COVID-19 diagnosis, and disease management.

Determining normal values for lower trachea and bronchi size in children by computed tomography (CT).

Normative data for central airway dimensions are a prerequisite to objectively assess large airway pathologies. Studies with computed tomography (CT) measurements of normal trachea and bronchi size in children are scarce. The purpose of this study is to establish normal values of central airway dimensions in children by CT. The study included chest CT studies from children aged 0-18 years. Any condition that predisposed the patient to have an abnormal tracheal or bronchial size was excluded. Airway diameters and cross-sectional area (CSA) were measured using double oblique reconstructions at five levels: proximal trachea, mid-trachea, distal trachea, right main bronchus, and left main bronchus. The inclusion criteria were met by 110 subjects (mean age, 10.8 years; SD, 5.2 years). Various regression models that considered the relationship between patient demographics and anteroposterior (AP) diameter, transverse diameter, and CSA at each of the five levels were assessed. R2 was utilized to select the best model. Multiple formulae (using patient age) were developed to calculate expected normal dimensions for five levels in the central airways on the natural log scale. Finally, z-scores were obtained for central airway dimensions at these five levels. Normative data in pediatric central airways are crucial to identify large airway pathologies. We propose using the formulae devised in our study to calculate the predicted dimensions of central airways and their z-scores in pediatric patients. Normative data from our study will aid in objective quantification of central airways, increase clinician confidence, and provide appropriate patient care.

Chest Radiograph (CXR) Manifestations of the Novel Coronavirus Disease 2019 (COVID-19): A Mini-review.

Coronavirus disease 2019 (COVID-19) is highly contagious and has claimed more than one million lives, besides causing hardship and disruptions. The Fleischner Society has recommended chest X-ray (CXR) in detecting cases at high risk of disease progression, for triaging suspected patients with moderate-to-severe illness, and for eliminating false negatives in areas with high pre-test probability or limited resources. Although CXR is less sensitive than real-- time reverse transcription-polymerase chain reaction (RT-PCR) in detecting mild COVID-19, it is nevertheless useful because of equipment portability, low cost and practicality in serial assessments of disease progression among hospitalized patients. This study aims to review the typical and relatively atypical CXR manifestations of COVID-19 pneumonia in a tertiary care hospital. The CXRs of 136 COVID-19 patients confirmed through real-time RT-PCR from March to May 2020 were reviewed. A literature search was performed using PubMed. A total of 54 patients had abnormal CXR whilst the others were normal. Typical CXR findings included pulmonary consolidation or ground-glass opacities in a multifocal, bilateral peripheral, or lower zone distribution, whereas atypical CXR features comprised cavitation and pleural effusion. Typical findings of COVID-19 infection in chest computed tomography studies can also be seen in CXR. The presence of atypical features associated with worse disease outcome. Recognition of these features on CXR will improve the accuracy and speed of diagnosing COVID-19 patients.

Manifestaciones radiológicas de la melioidosis pulmonar. Serie de casos

Melioidosis is an endemic disease in Southeast Asia and Oceania caused by the gram-negative bacillus Burkholderia pseudomallei. We studied 15 adult patients from Colombia with microbiologically diagnosed pulmonary melioidosis. We reviewed 15 chest X-rays and 10 chest computed tomography (CT) studies. Of the 15 patients, 87% met the criteria for acute infection and 13% met the criteria for chronic infection. The most common findings on chest X-rays were consolidation (86%), nodules (26%), and cavitation (20%). On CT studies, consolidation and nodules were observed in 90% of cases; the areas of consolidation were predominantly located in the basal and central zones in 60%. Areas of cavitation were observed in 50%, pleural effusion in 60%, and mediastinal lymph nodes in 30%. In patients with acute pulmonary melioidosis (n=8), the findings observed were nodules (100%), mixed pattern with nodules and consolidation (87%), pleural effusion (88%), and mediastinal lymph nodes (25%). The two patients with chronic pulmonary melioidosis both had cavitation. Acute lung infection with B. Pseudomallei has radiologic manifestations similar to those of pneumonia due to other causes. In areas where the disease is endemic, it is essential to include acute melioidosis in the differential diagnosis of pulmonary nodules and chronic melioidosis in the differential diagnosis of cavitated chronic lung lesions.

Impact of the COVID-19 pandemic on the activity of the Radiological Emergency Department: the experience of the Maggiore della Carit\xe0 Hospital in Novara

PurposeDuring the first peak of the COVID-19 pandemic, the activity of Emergency Departments worldwide changed dramatically, focusing on diagnosis and care of the Sars-Cov-2 associated disease. These major changes also involved the activity of the Emergency Radiology Department (ERD). This study aimed to analyse the impact of the COVID-19 pandemic on imaging studies, both in terms of the amount, frequency and subspecialty of different imaging modalities requested to the ERD of the Maggiore della Carità Hospital in Novara (Italy).MethodsTo this end, our observational study took into account the imaging studies requested by the emergency department during three-time spans. These were defined as phase 0 (pre-pandemic), phase 1 (pandemic peak with complete lockdown) and phase 2 (post-pandemic peak with partial lifting of restrictive measures), as derived from Italian urgent decrees by the President of the Council of Ministers (DPCM) which established the duration and entity of the lockdown measures throughout the pandemic. The dataset was processed and then compared with Pearson’s chi-squared test.ResultsDuring the pandemic peak, our data showed a significant drop in the total number of studies requested and a significant rise in computed tomography (CT) studies. In particular, a statistically significant increase in chest CT studies was found, probably due to the high sensitivity of this imaging method in identifying pulmonary involvement during respiratory tract infection of possible viral etiology (SARS-Cov-2). Moreover, we observed a statistically significant decrease of X-ray (XR) and ultrasound (US) studies during phase 1 compared to phase 0 and phase 2 probably due to a reduction in the numbers of ER visits for minor traumas given the mobility restrictions and people hesitancy in visiting the ER due to fear of contagion.ConclusionsWe can conclude that the activity of the ERD was heavily impacted by the SARS-Cov-2 pandemic. Further studies will be needed to estimate the impact of the pandemic on public health in terms of excess mortality related to delayed diagnosis and care of non-COVID diseases.

Chest computed tomography findings in different phases of SARS-CoV-2 infection

ObjectiveTo compare the findings on chest computed tomography (CT) in patients with COVID-19 during different phases of the disease and to evaluate the reproducibility of a visual radiologic score for estimating the extent of lung involvement. MethodsWe retrospectively reviewed chest CT studies from 182 patients with RT-PCR findings positive for SARS-CoV-2. Patients were classified according to the time elapsed from the onset of symptoms, as follows: early (0–4 days), intermediate/progressive (5–9 days), or advanced (≥10 days). We analysed the frequency of each radiologic finding, as well as the pattern, appearance, and predominant distribution of lung involvement. A visual tomographic score (range, 0−25) was used to estimate the extent of involvement in each lobe and in the total lung volume. ResultsThe predominant CT finding was the ground-glass pattern (n = 110; 60.4%), the most common distribution was peripheral (n = 116; 66.7%), and the most prevalent appearance was typical (n = 112; 61.5%). The halo sign was seen most frequently in the early phase (25%), whereas ground-glass opacities were more common in the intermediate/progressive and advanced phases. The median severity score was 10 (IQR: 5–13), and the scores increased as the disease progressed. The interobserver agreement (kappa) was 0.92 for the appearance, 0.84 for the distribution, 0.70 for the predominant pattern, and 0.89 for the visual score. ConclusionThe CT findings in patients with COVID-19 vary with the course of the infection. The proposed visual radiologic score is a simple, reproducible, and reliable tool for assessing lung involvement in COVID-19 pneumonia.

What is the potential for over-compression using current paediatric chest compression guidelines? — A chest computed tomography study

AimWe explored the potential for over-compression from current paediatric chest compression depth guidelines using chest computed tomography(CT) images of a large, heterogenous, Asian population. MethodsA retrospective review of consecutive children, less than 18-years old, with chest CT images performed between from 2005 to 2017 was done. Demographic data were extracted from the electronic medical records. Measurements for internal and external anterior-posterior diameters (APD) were taken at lower half of the sternum. Simulated chest compressions were performed to evaluate the proportion of the population with residual internal cavity dimensions less than 0 mm (RICD < 0 mm, representing definite over-compression; with chest compression depth exceeding internal APD), and RICD less than 10 mm (RICD < 10 mm, representing potential over-compression). Results592 paediatric chest CT studies were included for the study. Simulated chest compressions of one-third external APD had the least potential for over-compression; no infants and 0.3% children had potential over-compression (RICD < 10 mm). 4 cm simulated chest compressions led to 18% (95% CI 13%–24%) of infants with potential over-compression, and this increased to 34% (95% CI 27%–41%) at 4.4 cm (upper limit of “approximately” 4 cm; 4 cm + 10%). 5 cm simulated compressions resulted in 8% (95% CI 4%–12%) of children 1 to 8-years-old with potential over-compression, and this increased to 22% (95% CI 16%–28%) at 5.5 cm (upper limit of “approximately” 5 cm, 5 cm + 10%). ConclusionIn settings whereby chest compression depths can be accurately measured, compressions at the current recommended chest compression of approximately 4 cm (in infants) and 5 cm (in young children) could result in potential for over-compression.

Thoracic imaging tests for the diagnosis of COVID-19.

BackgroundThe respiratory illness caused by SARS‐CoV‐2 infection continues to present diagnostic challenges. Our 2020 edition of this review showed thoracic (chest) imaging to be sensitive and moderately specific in the diagnosis of coronavirus disease 2019 (COVID‐19). In this update, we include new relevant studies, and have removed studies with case‐control designs, and those not intended to be diagnostic test accuracy studies.ObjectivesTo evaluate the diagnostic accuracy of thoracic imaging (computed tomography (CT), X‐ray and ultrasound) in people with suspected COVID‐19.Search methodsWe searched the COVID‐19 Living Evidence Database from the University of Bern, the Cochrane COVID‐19 Study Register, The Stephen B. Thacker CDC Library, and repositories of COVID‐19 publications through to 30 September 2020. We did not apply any language restrictions.Selection criteriaWe included studies of all designs, except for case‐control, that recruited participants of any age group suspected to have COVID‐19 and that reported estimates of test accuracy or provided data from which we could compute estimates.Data collection and analysisThe review authors independently and in duplicate screened articles, extracted data and assessed risk of bias and applicability concerns using the QUADAS‐2 domain‐list. We presented the results of estimated sensitivity and specificity using paired forest plots, and we summarised pooled estimates in tables. We used a bivariate meta‐analysis model where appropriate. We presented the uncertainty of accuracy estimates using 95% confidence intervals (CIs).Main resultsWe included 51 studies with 19,775 participants suspected of having COVID‐19, of whom 10,155 (51%) had a final diagnosis of COVID‐19. Forty‐seven studies evaluated one imaging modality each, and four studies evaluated two imaging modalities each. All studies used RT‐PCR as the reference standard for the diagnosis of COVID‐19, with 47 studies using only RT‐PCR and four studies using a combination of RT‐PCR and other criteria (such as clinical signs, imaging tests, positive contacts, and follow‐up phone calls) as the reference standard.Studies were conducted in Europe (33), Asia (13), North America (3) and South America (2); including only adults (26), all ages (21), children only (1), adults over 70 years (1), and unclear (2); in inpatients (2), outpatients (32), and setting unclear (17).Risk of bias was high or unclear in thirty‐two (63%) studies with respect to participant selection, 40 (78%) studies with respect to reference standard, 30 (59%) studies with respect to index test, and 24 (47%) studies with respect to participant flow.For chest CT (41 studies, 16,133 participants, 8110 (50%) cases), the sensitivity ranged from 56.3% to 100%, and specificity ranged from 25.4% to 97.4%. The pooled sensitivity of chest CT was 87.9% (95% CI 84.6 to 90.6) and the pooled specificity was 80.0% (95% CI 74.9 to 84.3). There was no statistical evidence indicating that reference standard conduct and definition for index test positivity were sources of heterogeneity for CT studies.Nine chest CT studies (2807 participants, 1139 (41%) cases) used the COVID‐19 Reporting and Data System (CO‐RADS) scoring system, which has five thresholds to define index test positivity. At a CO‐RADS threshold of 5 (7 studies), the sensitivity ranged from 41.5% to 77.9% and the pooled sensitivity was 67.0% (95% CI 56.4 to 76.2); the specificity ranged from 83.5% to 96.2%; and the pooled specificity was 91.3% (95% CI 87.6 to 94.0). At a CO‐RADS threshold of 4 (7 studies), the sensitivity ranged from 56.3% to 92.9% and the pooled sensitivity was 83.5% (95% CI 74.4 to 89.7); the specificity ranged from 77.2% to 90.4% and the pooled specificity was 83.6% (95% CI 80.5 to 86.4).For chest X‐ray (9 studies, 3694 participants, 2111 (57%) cases) the sensitivity ranged from 51.9% to 94.4% and specificity ranged from 40.4% to 88.9%. The pooled sensitivity of chest X‐ray was 80.6% (95% CI 69.1 to 88.6) and the pooled specificity was 71.5% (95% CI 59.8 to 80.8).For ultrasound of the lungs (5 studies, 446 participants, 211 (47%) cases) the sensitivity ranged from 68.2% to 96.8% and specificity ranged from 21.3% to 78.9%. The pooled sensitivity of ultrasound was 86.4% (95% CI 72.7 to 93.9) and the pooled specificity was 54.6% (95% CI 35.3 to 72.6).Based on an indirect comparison using all included studies, chest CT had a higher specificity than ultrasound. For indirect comparisons of chest CT and chest X‐ray, or chest X‐ray and ultrasound, the data did not show differences in specificity or sensitivity.Authors' conclusionsOur findings indicate that chest CT is sensitive and moderately specific for the diagnosis of COVID‐19. Chest X‐ray is moderately sensitive and moderately specific for the diagnosis of COVID‐19. Ultrasound is sensitive but not specific for the diagnosis of COVID‐19. Thus, chest CT and ultrasound may have more utility for excluding COVID‐19 than for differentiating SARS‐CoV‐2 infection from other causes of respiratory illness.Future diagnostic accuracy studies should pre‐define positive imaging findings, include direct comparisons of the various modalities of interest in the same participant population, and implement improved reporting practices.

Pulmonary embolism in COVID-19: Ancillary findings on chest CT angiography.

Pulmonary embolism in COVID-19: Ancillary findings on chest CT angiography.