Chest Computed Tomography Scan Research Articles

Lung Cancer Screening: Early Detection Decreases Mortality.

Lung cancer remains the number one cancer related mortality in the United States . While it is the third most diagnosed cancer, it is often found at an advanced stage. Survival rates for stage I lung cancer are above 70% while survival rates for stage IV lung cancer are less than 10% at five years. Methods to detect lung cancer at an earlier stage when it can be more effectively treated have been investigated for many years. These included regular chest x-rays (CXRs) and sputum samples. Unfortunately, these testing modalities did not show any benefit. This changed in 2011 when data from the National Lung Screening Trial were published. This landmark trial showed conclusively that a low-radiation dose chest computed tomography scan (LDCT) performed annually in patients with a heavy smoking history reduced lung cancer related mortality by 20%. These results have led to a nationwide effort to increase lung cancer screening. While the number of eligible patients that are being screened on a national level remains modest, significant efforts are being made at the state and local levels to increase awareness and to improve screening. These efforts have also targeted underserved areas and are focused on reducing disparities in access.

Computed Tomography Spectrum of Complications in Usual Interstitial Pneumonia Pattern in a Tertiary Care Hospital: A Descriptive Cross- sectional Study.

Idiopathic pulmonary fibrosis is the most prevalent form of interstitial lung disease, which presents as usual interstitial pneumonia on histopathology and imaging. It leads to significant lung scarring, damage, and fibrosis and is associated with a high degree of mortality, repeated hospital admissions, and oxygen dependence. Many complications are associated with idiopathic pulmonary fibrosis, which further increases the morbidity of patients. High-resolution computed tomography chest is the imaging modality of choice for usual interstitial pneumonia tracking its progression, evaluating treatment response, and detecting potential complications. This descriptive cross-sectional study was approved by the Institutional Ethics Committee (Reference number: IEC-INT/2023/Study-1256). Departmental computed tomography report database from November, 2017 to June, 2018 was reviewed and scans with imaging features consistent with the 'usual interstitial pneumonia' pattern were identified. Total sampling method was used and two independent radiologists, blinded to the patient's clinical information, reviewed the high-resolution computed tomography chest scans to assess for imaging features of usual interstitial pneumonia and associated complications. Data was collected and analyzed using Microsoft Excel. There were 65 patients reported as unusual interstitial pneumonia pattern. Emphysema and pneumothorax were identified in 4 (6.15%) and 1 (1.53%) scans, respectively. Two (3.08%) scans showed features of pulmonary arterial hypertension. Ten (15.38%) scans exhibited findings consistent with co-existent or superimposed pulmonary infection. Additionally, features of lung malignancy were identified in high-resolution computed tomography scans of 5 (7.69%) patients. Patients with UIP often experience severe lung scarring, and frequent complications, and require regular chest CT scans to monitor disease progression and identify potential complications.

Löfgren syndrome, characteristics of Japanese cases: a case and a review of the literature.

Löfgren syndrome (LS) is a sarcoidosis subtype characterized by an acute disease course, bilateral hilar lymphadenopathy, erythema nodosum, and ankle arthritis. LS in Caucasians appears to be self-limiting; however, our patients required glucocorticoid (GC) treatment. Here, we present a case of LS and review the literature to identify the characteristics of the Japanese patients with LS. Sixty-six-year-old woman was referred to our hospital; she initially presented with an acute onset of low-grade fever and ankle arthritis, followed by erythema nodosum. Skin biopsy revealed a non-caseating granuloma, and chest computed tomography scan displayed bilateral hilar lymphadenopathy; she was diagnosed with LS. Her arthralgia ameliorated spontaneously, but erythema persisted, necessitating GC treatment. Literature review revealed that the Japanese LS patients showed more fever, were more frequently treated with GC and more patients seemed to relapse, which may be explained by the absence of human leukocyte antigen-DR isotype 3, a good prognostic allele in Caucasians. Japanese LS may cause severe symptoms after development because of the differences in human leukocyte antigen from foreign countries. For early diagnosis, it is important to evaluate erythema nodosum and bilateral hilar lymphadenopathy in patients with polyarthritis involving ankle arthralgia.

Recognition and initial management of acute aortic dissection.

Acute aortic dissection is a cardiovascular emergency that should be recognised on presentation in the Emergency Department (ED) because clinical outcome is time-dependent. In suspected cases of acute aortic dissection, immediate imaging with chest computed tomography scan followed by transthoracic echocardiography (TTE) is essential to confirm diagnosis. Immediate medical management is aimed at controlling the heart rate (60-80 beats/min), systolic blood pressure (100-120 mmHg) and pain. Patients with Type A acute aortic dissection should immediately be referred to the cardiothoracic surgeons for emergency aortic surgery while those with Type B acute aortic dissection should be referred to the vascular surgeons for surgical/endovascular interventions if indicated.

Clinical and radiological features of a cluster of immunocompetent adolescents with varicella pneumonia: a descriptive study.

Varicella pneumonia is one of the most common and severe complications of chickenpox infection. This study aimed to describe the clinical and radiological features of varicella pneumonia in a cluster of immunocompetent adolescents. A retrospective analysis was conducted on a cohort of adolescent patients diagnosed with varicella pneumonia at Wuhan Jinyintan Hospital between February 2023 and May 2023. The clinical and imaging data were collected and analyzed. A total of 116 patients were divided into two groups by the absence (group 1, n=57) or presence (group 2, n=59) of lower respiratory symptoms for data comparison. Among 116 patients (median age, 16 years; 60 males), rash (100%) was the most prevalent clinical symptom. The most common respiratory symptom and sign were fever (42.2%) and coarse breath sounds (41.4%). Chest computed tomography (CT) performed within five days of symptoms onset revealed multiple (89.7%), peripheral (51.7%), and ill-defined (73.3%) lung nodules in most patients, which gradually improved 6-10 days after symptom onset. Group 2 had higher levels of interleukin-6 (P<0.001), C-reactive protein (P=0.02), serum amyloid-A protein (P=0.002), longer hospital stays (P=0.04), more involved lung lobes (P=0.02), and a higher incidence of multiple nodules (P=0.043) than those of group 1. In immunocompetent adolescents, clustered varicella pneumonia often presents as mild and more uniform in clinical and radiological presentations than sporadic cases. The most common CT findings were multiple pulmonary nodules. Patients with lower respiratory symptoms exhibited more severe clinical and radiological manifestations. Generally, it is not recommended that patients undergo frequent CT scans in a short period.

Tumor cavitation in patients with non-small-cell lung cancer receiving anti-angiogenic therapy with apatinib.

Cavities have been reported in approximately 20% of lung cancer after anti-angiogenesis treatments. However, the effect of which on treatment outcomes remains unclear. This study sought to investigate the incidence and radiographic patterns of tumor cavitation in patients with non-small cell lung cancer (NSCLC) treated with apatinib, and its associations with patients' clinical characteristics and outcomes. A total of 300 patients with NSCLC treated with apatinib were retrospectively identified. Baseline and follow-up chest computed tomography scans were reviewed to identify tumor cavitation, and the subsequent filling-in of the cavitation. A multivariate logistic regression analysis was conducted to identify the factors associated with tumor cavitation. Survival curves were constructed using the Kaplan-Meier method and compared using the log-rank test. Of the 300 patients, 51 (17.0%) developed lung cavitation after initiating apatinib therapy. The results of the multivariate analysis showed that apatinib combination therapy (vs. apatinib monotherapy, odds ratio: 0.593, 95% confidence interval: 0.412-0.854, P=0.005) was significantly associated with tumor cavitation. Patients with tumor cavitation had significantly longer progression-free survival (PFS) than those without cavitation (8.2 vs. 5.2 months, P<0.01). Of the patients, 18 had cavity filling after progression, while 13 had persistent cavities after progression. The corresponding median PFS times were 11.9 and 3.2 months in patients with filled and persistent cavities after disease progression, respectively (P<0.001). Tumor cavitation occurred in 17% of the NSCLC patients treated with apatinib and was associated with better PFS. Patients who had cavities filled after progression had a better prognosis than those with persistent cavities.

Relationship between imaging-derived parameters and circulating microRNAs to study the degree of lung involvement in hospitalized geriatric patients with COVID-19 pneumonia.

Chest computed tomography (CT) scan is useful to evaluate the type and extent of lung lesions in coronavirus disease 2019 (COVID-19) pneumonia. This study explored the association between radiological parameters and various circulating serum-derived markers, including microRNAs, in older patients with COVID-19 pneumonia. A retrospective analysis was designed to study geriatric patients (≥75 years) with COVID-19 pneumonia, who underwent chest CT scan on admission, and for whom clinical data and serum samples were obtained. To quantify the extent of lung involvement, CT-score, the percentage of healthy lung (HL%), the percentage of ground glass opacity (GGO%),and the percentage of lung consolidation were assessed using computer-aided tools. The association of these parameters with two circulating microRNAs, miR-483-5p and miR-320b, previously identified as biomarkers of mortality risk in COVID-19 geriatric patients, was tested. A total of 73 patients with COVID-19 pneumonia were evaluable (median age 85 years; interquartile range 82-90 years). Among chest CT-derived parameters, thepercentage of lung consolidation (HR 1.08, 95% CI 1.02-1.14), CT-score (HR 1.14, 95% CI 1.03-1.25), and HL% (HR 0.97, 95% CI 0.95-0.99) emerged as significant predictors of mortality, whereas non-significant trends toward increased mortality were observed in patients with higher GGO%. We also found a significant positive association between serum miR-483-5p and GGO% (correlation coefficient 0.28; P = 0.018) and a negative association with HL% (correlation coefficient -0.27; P = 0.023). Overall, the extent of lung consolidation can be confirmed as a prognostic parameter of COVID-19 pneumonia in older patients. Among various serum-derived markers, miR-483-5p can help in exploring the degree of lung involvement, due to its association with higher GGO% and lower HL%. Geriatr Gerontol Int 2024; ••: ••-••.

Low skeletal muscle mass is associated with inferior preoperative and postoperative shoulder function in elderly rotator cuff tear patients

BackgroundThe age-related loss of skeletal muscle mass is an important characteristic of sarcopenia, an increasingly recognized condition with systemic implications. However, its association with shoulder function in elderly patients with rotator cuff tears (RCT) remains unknown. This study aimed to investigate the relationship between low skeletal muscle mass and shoulder function in elderly RCT patients.MethodsA retrospective analysis was conducted on RCT patients who underwent chest computed tomography (CT) scans for clinical evaluation. Preoperative CT scan images of the chest were used to calculate the cross-sectional area (CSA) of thoracic muscle at the T4 level. The medical records were reviewed. Shoulder function was assessed using the ASES score and CMS score both preoperatively and at the final follow-up. Data on the preoperative range of motion (ROM) for the affected shoulder, were collected for analysis. Subgroup analyses by sex were also performed.ResultsA total of 283 RCT patients, consisting of 95 males and 188 females, with a mean age of 66.22 ± 4.89(range, 60–95 years) years were included in this retrospective study. The low muscle mass group showed significantly higher level of c-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) compared to the normal group(3.75 ± 6.64 mg/L vs. 2.17 ± 2.30 mg/L, p = 0.021; 19.08 ± 12.86 mm/H vs.15.95 ± 10.76 mm/H, p = 0.038; respectively). In the normal group, pre-operative passive ROM, including forward elevation, abduction, lateral rotation, and abductive external rotation, was significantly better than that in the low muscle mass group (127.18 ± 34.87° vs. 89.76 ± 50.61°; 119.83 ± 45.76° vs. 87.16 ± 53.32°; 37.96 ± 28.33° vs. 25.82 ± 27.82°; 47.71 ± 23.56° vs. 30.87 ± 27.76°, all p < 0.01, respectively). Similar results were found in the active ROM of the shoulder. The female low muscle mass group exhibited significantly poorer passive and active ROM (p < 0.05). The post-operative ASES scores and CMS scores of the female low muscle mass group were also statistically worse than those of the female normal group (p < 0.05).ConclusionsThe results of present study revealed that the low skeletal muscle mass is associated with inferior ROM of the shoulder and per- and post-operative shoulder function, especially for elderly female patients.

Risk factors of mortality in patients with rheumatoid arthritis-associated interstitial lung disease: a single-centre prospective cohort study

ObjectivesTo determine the risk factors for mortality in Korean patients with rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) in comparison to patients with RA but without ILD (RA-nonILD).MethodsData were extracted from a single-centre prospective cohort of RA patients with a chest computed tomography scan at an academic referral hospital in Korea. Patients with RA-ILD enroled between May 2017 and August 2022 were selected, and those without ILD were selected as comparators. The mortality rate was calculated, and the causes of each death were investigated. We used Cox proportional hazard regression with Firth’s penalised likelihood method to identify the risk factors for mortality in patients with RA-ILD.ResultsA total of 615 RA patients were included: 200 with ILD and 415 without ILD. In the RA-ILD group, there were 15 deaths over 540.1 person-years (PYs), resulting in mortality rate of 2.78/100 PYs. No deaths were reported in the RA-nonILD group during the 1669.9 PYs. The primary causes of death were infection (nine cases) and lung cancer (five cases), with only one death attributed to ILD aggravation. High RA activity (adjusted HR 1.87, CI 1.16–3.10), baseline diffusing capacity for carbon monoxide (DLCO) < 60% (adjusted HR 4.88, 95% CI 1.11–45.94), and usual interstitial pneumonia (UIP) pattern (adjusted HR 5.13, 95% CI 1.00–57.36) were identified as risk factors for mortality in RA-ILD patients.ConclusionPatients with RA-ILD have an elevated risk of mortality compared with those without ILD. Infection-related deaths are the main causes of mortality in this population. High RA activity, low DLCO, and the UIP pattern are significantly associated with the mortality in patients with RA-ILD.

Laboratory data and broncho-alveolar lavage on Covid-19 patients with no intensive care unit admission: Correlation with chest CT features and clinical outcomes.

Broncho-alveolar lavage (BAL) is indicated in cases of uncertain diagnosis but high suspicion of Sars-Cov-2 infection allowing to collect material for microbiological culture to define the presence of coinfection or super-infection. This prospective study investigated the correlation between chest computed tomography (CT) findings, Covid-19 Reporting and Data System score, and clinical outcomes in Coronavirus disease 2019 (Covid-19) patients who underwent BAL with the aim of predicting outcomes such as lung coinfection, respiratory failure, and hospitalization length based on chest CT abnormalities. Study population included 34 patients (range 38-90 years old; 20 males, 14 females) with a positive nucleic acid amplification test for Covid-19 infection, suitable BAL examination, and good quality chest CT scan in the absence of lung cancer history. Pulmonary coinfections were found in 20.6% of patients, predominantly caused by bacteria. Specific correlations were found between right middle lobe involvement and pulmonary co-infections. Severe lung injury (PaO2/FiO2 ratio of 100-200) was associated with substantial involvement of right middle, right upper, and left lower lobes. No significant correlation was found between chest CT findings and inflammatory markers (C-reactive protein, procalcitonin) or hospitalization length of stay. Specific chest CT patterns, especially in right middle lobe, could serve as indicators for the presence of co-infections and disease severity in noncritically ill Covid-19 patients, aiding clinicians in timely interventions and personalized treatment strategies.

Preliminary Results of Developing Imaging Complexity Biomarkers for the Incidence of Severe Radiation Pneumonitis Following Radiotherapy in Non-Small Cell Lung Cancer Patients with Underlying Idiopathic Pulmonary Fibrosis.

Background: Idiopathic pulmonary fibrosis (IPF) has the potential to cause fatal pulmonary toxicity after radiotherapy and can increase the morbidity and mortality of non-small-cell lung cancer (NSCLC) patients. In this context, we aimed to develop imaging complexity biomarkers to predict the incidence of severe pulmonary toxicity in patients with NSCLC who have underlying IPF and are treated with radiotherapy. Methods: We retrospectively reviewed the medical records of 19 patients with NSCLC who had underlying IPF and were treated with radiotherapy at the Korea University Guro Hospital between March 2018 and December 2022. To quantify the morphometric complexity of the lung parenchyma, box-counting fractal dimensions and lacunarity analyses were performed on pre-radiotherapy simulation chest computed tomography scans. Results: Of the 19 patients, the incidence of grade 3 or higher radiation pneumonitis was observed in 8 (42.1%). After adjusting for age, sex, smoking status, histology, and diffusing capacity of the lung for carbon monoxide, eight patients with a lower fractal dimension showed a significantly higher hazard ratio of 7.755 (1.168-51.51) for grade 3 or higher pneumonitis than those with a higher fractal dimension. Patients with lower lacunarity exhibited significantly lower hazards in all models, both with and without adjustments. The lower-than-median lacunarity group also showed significantly lower incidence curves for all models built in this study. Conclusions: We devised a technique for quantifying morphometric complexity in NSCLC patients with IPF on radiotherapy and discovered lacunarity as a potential imaging biomarker for grade 3 or higher pneumonitis.

Radiation Doses in Routine CT Examinations for Adult Patients in Saudi Arabia: A Systematic Review.

Computed tomography (CT) is an important imaging technique that produces detailed cross-sectional images for diagnosing medical conditions. However, the associated radiation exposure raises concerns. Establishing diagnostic reference levels (DRLs) helps identify unusual radiation doses and optimize exposure while maintaining diagnostic image quality. The purpose of this systematic review is to review the radiation doses received by adult patients in the head, chest, abdomen, pelvis, abdomen-pelvis (AP), and combined chest, abdomen, and pelvis (CAP) CT scans in Saudi Arabia. A search was conducted in several databases including PubMed and Google Scholar to identify studies that have established DRLs or determined radiation dose for adult CT examinations. Only studies that specifically assessed DRLs in actual adult patients were considered for inclusion. Out of a total of 31 articles that were identified as eligible, 13 were included after a thorough screening process. The values of CTDIv, DLP, and effective doses were determined. The review discovered that CTDIv and DLP were the most frequently used dosimetric quantities. The mean values in terms of CTDIv for head, chest, abdomen, pelvis, AP, and CAP ranged from 40.67 to 61.80 mGy, 5.80 to 14.90 mGy, 8.60 to 16.15 mGy, 10.80 to 17.35 mGy, 14.10 to 16.84 mGy, and 12.00 to 22.94 mGy, respectively. The mean values in terms of DLP for head, chest, abdomen, pelvis, AP, and CAP ranged from 757 to 1212 mGy.cm, 243 to 657 mGy.cm, 369.5 to 549 mGy.cm, 379.6 to 593 mGy.cm, 658 to 940.43 mGy.cm, and 740 to 1493.8 mGy.cm, respectively. There is a fluctuation in radiation dose among CT centers, highlighting a need to provide proper education and training to radiographers. It is recommended to establish a universally accepted standardized protocol based on weight, equivalent diameter, or cross-sectional area for accurate comparisons with national and international DRLs.

Chest computed tomography manifestations in neonates with chronic granulomatous disease

To study chest computed tomography (CT) manifestations in neonates with chronic granulomatous disease (CGD) to provide clues for early diagnosis of this disease. A retrospective analysis was conducted on the clinical data and chest CT scan results of neonates diagnosed with CGD from January 2015 to December 2022 at Anhui Provincial Children's Hospital. Nine neonates with CGD were included, with eight presenting respiratory symptoms as the initial sign. Chest CT findings included: consolidation in all 9 cases; nodules in all 9 cases, characterized by multiple, variably sized scattered nodules in both lungs; masses in 4 cases; cavities in 3 cases; abscesses in 6 cases; bronchial stenosis in 2 cases; pleural effusion, interstitial changes, and mediastinal lymphadenopathy each in 1 case. CT enhancement scans showed nodules and masses with uneven or ring-shaped enhancement; no signs of pulmonary emphysema, lung calcification, halo signs, crescent signs, bronchiectasis, or scar lesions were observed. There was no evidence of rib or vertebral bone destruction. Fungal infections were present in 8 of the 9 cases, including 6 with Aspergillus infections; three of these involved mixed infections with Aspergillus, with masses most commonly associated with mixed Aspergillus infections (3/4). The primary manifestations of neonatal CGD on chest CT are consolidation, nodules, and/or masses, with Aspergillus as a common pathogen. These features can serve as early diagnostic clues for neonatal CGD.

Intracranial dissemination of Klebsiella pneumoniae originating from pulmonary infection: a case report

BackgroundMetastatic brain abscesses caused by Klebsiella pneumoniae are extremely rare but life-threatening conditions. To depict a unique case of the middle-aged hypertensive man with an unusual presentation of metastatic brain abscesses originating from a pleural abscess caused by Klebsiella pneumoniae and subsequently leading to loss of consciousness (LOC).Case reportA 52-year-old Iranian man with a history of hypertension presented to the emergency department with a five-day history of worsening cough, high-grade fever, shortness of breath, chest pain, fatigue, and a productive cough. Laboratory tests revealed leukocytosis, elevated C-reactive protein, and respiratory alkalosis. A chest computed tomography scan confirmed pneumonia, and a brain scan revealed multiple hypodense lesions. Despite antibiotic therapy, the patient's condition worsened, leading to confusion, disorientation, and loss of consciousness. Magnetic resonance imaging revealed multiple ring-enhancing lesions, suggesting an abscess formation. Bronchial washings and BAL samples confirmed a lower respiratory tract infection. Cultures from the bronchial washings grew Klebsiella pneumoniae.ConclusionsMetastatic brain abscesses caused by Klebsiella pneumoniae are exceedingly rare but life-threatening conditions. Timely diagnosis and effective antimicrobial treatment are critical for patient outcomes. This case underscores the significance of recognizing atypical presentations of bacterial infections, as early detection and appropriate management can significantly impact patient outcomes.

Midregional Proatrial Natriuretic Peptide (MRproANP) is associated with vertebral fractures and low bone density in patients with chronic obstructive pulmonary disease (COPD)

BackgroundPatients with COPD are often affected by loss of bone mineral density (BMD) and osteoporotic fractures. Natriuretic peptides (NP) are known as cardiac markers, but have also been linked to fragility-associated fractures in the elderly. As their functions include regulation of fluid and mineral balance, they also might affect bone metabolism, particularly in systemic disorders such as COPD.Research questionWe investigated the association between NP serum levels, vertebral fractures and BMD assessed by chest computed tomography (CT) in patients with COPD.MethodsParticipants of the COSYCONET cohort with CT scans were included. Mean vertebral bone density on CT (BMD-CT) as a risk factor for osteoporosis was assessed at the level of TH12 (AI-Rad Companion), and vertebral compression fractures were visually quantified by two readers. Their relationship with N-terminal pro-B-type natriuretic peptide (NT-proBNP), Mid-regional pro-atrial natriuretic peptide (MRproANP) and Midregional pro-adrenomedullin (MRproADM) was determined using group comparisons and multivariable analyses.ResultsAmong 418 participants (58% male, median age 64 years, FEV1 59.6% predicted), vertebral fractures in TH12 were found in 76 patients (18.1%). Compared to patients without fractures, these had elevated serum levels (p ≤ 0.005) of MRproANP and MRproADM. Using optimal cut-off values in multiple logistic regression analyses, MRproANP levels ≥ 65 nmol/l (OR 2.34; p = 0.011) and age (p = 0.009) were the only significant predictors of fractures after adjustment for sex, BMI, smoking status, FEV1% predicted, SGRQ Activity score, daily physical activity, oral corticosteroids, the diagnosis of cardiac disease, and renal impairment. Correspondingly, MRproANP (p < 0.001), age (p = 0.055), SGRQ Activity score (p = 0.061) and active smoking (p = 0.025) were associated with TH12 vertebral density.InterpretationMRproANP was a marker for osteoporotic vertebral fractures in our COPD patients from the COSYCONET cohort. Its association with reduced vertebral BMD on CT and its known modulating effects on fluid and ion balance are suggestive of direct effects on bone mineralization.Trial registrationClinicalTrials.gov NCT01245933, Date of registration: 18 November 2010.

Better performance of deep learning pulmonary nodule detection using chest radiography with pixel level labels in reference to computed tomography: data quality matters

Labeling errors can significantly impact the performance of deep learning models used for screening chest radiographs. The deep learning model for detecting pulmonary nodules is particularly vulnerable to such errors, mainly because normal chest radiographs and those with nodules obscured by ribs appear similar. Thus, high-quality datasets referred to chest computed tomography (CT) are required to prevent the misclassification of nodular chest radiographs as normal. From this perspective, a deep learning strategy employing chest radiography data with pixel-level annotations referencing chest CT scans may improve nodule detection and localization compared to image-level labels. We trained models using a National Institute of Health chest radiograph-based labeling dataset and an AI-HUB CT-based labeling dataset, employing DenseNet architecture with squeeze-and-excitation blocks. We developed four models to assess whether CT versus chest radiography and pixel-level versus image-level labeling would improve the deep learning model’s performance to detect nodules. The models' performance was evaluated using two external validation datasets. The AI-HUB dataset with image-level labeling outperformed the NIH dataset (AUC 0.88 vs 0.71 and 0.78 vs.0.73 in two external datasets, respectively; both p < 0.001). However, the AI-HUB data annotated at the pixel level produced the best model (AUC 0.91 and 0.86 in external datasets), and in terms of nodule localization, it significantly outperformed models trained with image-level annotation data, with a Dice coefficient ranging from 0.36 to 0.58. Our findings underscore the importance of accurately labeled data in developing reliable deep learning algorithms for nodule detection in chest radiography.

Main pulmonary artery diameter related to pneumonia severity.

The diameter (mPAD) of the main pulmonary artery (pulmonary artery trunk) is a crucial indicator for cardiovascular health and prognoses in various conditions. Its enlargement is associated with increased mortality and severity in COVID-19-related pneumonia. However, its relevance to non-COVID pneumonia remains uncertain. The aim of this study was to establish an association between mPAD and the severity of non-COVID pneumonia. Eligible participants with qualified Chest Computed Tomography scans from November 2019 to February 2023 were recruited to a cross-sectional retrospective study. They were stratified into pneumonia and non-pneumonia cohorts. Exclusion criteria included pulmonary hypertension, polytrauma, lung neoplasia, or a history of pulmonary stenosis repair. The mPAD was measured in both groups, and medical records were reviewed to identify comorbidities. Pulmonary CT data were classified by pattern and severity, and the mPAD was measured perpendicularly to the long axis of the artery at the point of bifurcation on an axial slice. Analysis of 380 CT scans (52.6% men, 47.4% women; mean age 52.88 ± 17.58) revealed a significant difference in mPAD between pneumonia and non-pneumonia cases (mean difference: 1.19 mm, 95% CI [0.46, 1.92], p = 0.001). Age correlated positively with mPAD (r = 0.231, 95% CI [0.028, 0.069], p < 0.0001), and this correlation persisted after adjusting for confounders (r = 0.220, 95% CI [0.019, 0.073], p = 0.001). Ordinal logistic regression indicated 1.28 times higher odds of severe pneumonia with a larger diameter. The study highlights associations between mPAD, pneumonia, and severity, suggesting clinical relevance. Furthermore, the mPAD should be carefully considered in defining severity criteria for adverse outcomes in pneumonia patients. Further research is needed to refine clinical criteria on the basis of these findings.

Computed tomography predictors of increased transvenous lead extraction difficulty.

The ability of computed tomography (CT) characteristics to predict the difficulty of transvenous lead extraction (TLE) is an evolving subject. To identify CT characteristics associated with increased TLE difficulty. All consecutive patients undergoing TLE at the University of California San Diego from January 2018 to February 2022 were analyzed, utilizing the UC San Diego Lead Extraction Registry. Patients underwent cardiac-gated chest CT scans with intravenous contrast; all scans were reviewed by a single radiologist. Lead extraction was performed per standard institutional protocol with the initial use of a laser sheath and crossover to a mechanical sheath as needed. Multivariable linear and logistic regression analyses were performed to identify predictors of individual lead-removal fluoroscopy time and mechanical sheath use, as markers of extraction difficulty. A total of 343 patients were analyzed. The mean age of the study population was 63.8±15.4 years; 71% were male. The mean lead dwell-in duration was 8.6±5.7 years. In multivariable linear regression analysis, venous occlusion detected on CT was independently associated with higher individual lead-removal fluoroscopy time (p=0.004), when adjusting for clinical characteristics such as lead dwell time. In multivariable logistic regression analysis, calcification and venous occlusion were independently associated with a higher need for mechanical sheath use during TLE (odds ratio:5.08, p<0.001, 95% CI: 2.54-10.46) and (odds ratio:3.72, p<0.001, 95% CI: 1.89-7.35), respectively. In patients undergoing TLE, venous occlusion identified by chest CT is associated with increased fluoroscopy time. Patients with lead-associated calcification or venous occlusion detected by chest CT are each five and three times more likely to require crossover from laser to a mechanical sheath.

Extravascular protrusion of the Alterra adaptive prestent identified on surveillance computed tomography imaging.

The Alterra adaptive prestent is a novel self-expanding device designed to provide a landing zone for the 29 mm SAPIEN 3 valve to treat pulmonary regurgitation in patients with a right ventricular outflow tract that is too large for a balloon expandable valve alone. The mechanism of fixation for the Alterra prestent is radial force from the self-expanding stent frame, combined with a unique set of flared "tines" that protrude from both ends of the stent. In this report, we describe 6patients who underwent uncomplicated transcatheter pulmonary valve replacement with an Alterra adaptive prestent and SAPIEN 3 valve and had surveillance chest computed tomography (CT) scans performed 1 day to 21 months after implant. In each patient, the CT scan demonstrated extravascular extension of a portion of the Alterra prestent, without clinical sequelae, but with extension into the ascending aorta in 1 patient and contact with the ascending aorta, left pulmonary vein, or left atrial appendagein 3 others. Surveillance CT imaging shows that the Alterra prestent can perforate the pulmonary artery and/or right ventricle. Although no sequelae were seen in these patients, prestent perforation has the potential to be clinically important. Implanters should be aware of this finding and its potential implications. As experience with the Alterra prestent grows, it will be important to further define the risk factors, incidence, and implications of this phenomenon.

How I treat: Coronavirus disease 2019 in leukemic patients and hematopoietic cell transplant recipients.

Among immunocompromised hosts, leukemia patients, and hematopoietic cell transplant recipients are particularly vulnerable, facing challenges in balancing coronavirus disease 2019 (COVID-19) management with their underlying conditions. In this How I Treat article, we discuss how we approach severe acute respiratory syndrome coronavirus 2 infections in daily clinical practice, considering the existing body of literature and for topics where the available data are not sufficient to provide adequate guidance, we provide our opinion based on our clinical expertise and experience. Diagnostic approaches include nasopharyngeal swabs for polymerase chain reaction testing and chest computed tomography scans for symptomatic patients at risk of disease progression. Preventive measures involve strict infection control protocols and prioritizing vaccination for both patients and their families. Decisions regarding chemotherapy or hematopoietic cell transplantation in leukemia patients with COVID-19 require careful consideration of factors such as COVID-19 severity and treatment urgency. Treatment protocols include early initiation of antiviral therapy, with nirmatrelvir/ritonavir or remdesivir. For cases of prolonged viral shedding, distinguishing between viable and non-viable viruses remains challenging but is crucial for determining contagiousness and guiding management decisions. Overall, individualized approaches considering immune status, clinical presentation, and viral kinetics are essential for effectively managing COVID-19 in leukemia patients.