Chest Chest Computed Tomography Research Articles

Lentil aspiration pneumonitis

This patient has a complex medical history that includes intellectual disability, blindness, deafness, seizure disorder, tracheomalacia, and recurrent aspiration. He had a percutaneous endoscopic gastrostomy in place for tube feeding. He again presented with acute respiratory distress, hypoxemia, fever, and leukocytosis. Chest computed tomography (CT) revealed bilateral infiltrates and nodular densities. A previous chest CT done 6 years prior to admission revealed multiple micronodules scattered throughout both lung fields. The patient had had a previous lung biopsy 20 years prior to admission which revealed lentil starch material in bronchioles and multifocal foreign body giant cell reactions. The patient was treated with an empiric antibiotic regimen and improved. This case demonstrates the radiographic and histologic changes associated with lentil pneumonia which is an unusual type of aspiration pneumonia. Keywords: Lentil pneumonia, granulomas, aspiration, nodules

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.

Comparison of the equivalent doses of the eye lenses, thyroid, and mammary gland among three pediatric and one adult anthropomorphic phantom during the chest CT examinations using a 40mm volume helical scan.

Equivalent doses for the eye lenses, thyroid, and mammary glands were measured and compared between one adult and three pediatric anthropomorphic phantoms during chest computed tomography (CT) using 40mm volume helical scan on the Aquilion ONE GENESIS Edition CT equipment. Placing an optically stimulated luminescence dosemeter (OSLD) on the eye lenses, thyroid, and mammary gland, we measured and compared the equivalent dose of OSLD among different phantoms during chest CT using a helical scan. Compared with adults, the equivalent doses to the eye lens, thyroid, and mammary glands were ~81%, 77%, and 63% lower in newborns, 1-year-olds, and 5-year-olds using comparable image noise during chest CT.

Utility of block-matching and 3D filter for reproducibility of lung density and denoising in low-dose chest CT: A pilot study

PurposeThis study aimed to acquire an image quality consistent with that of full-dose chest computed tomography (CT) when obtaining low-dose chest CT images and to analyze the effects of block-matching and 3D (BM3D) filters on lung density measurements and noise reduction in lung parenchyma. MethodsUsing full-dose chest CT images, we evaluated lung density measurements and noise reduction in lung parenchyma images for low-dose chest CT. Three filters (median, Wiener, and the proposed BM3D) were applied to low-dose chest CT images for comparison and analysis with images from full-dose chest CT. To evaluate lung density measurements, we measured CT attenuation at the 15th percentile of the lung CT histogram. The coefficient of variation (COV) and contrast-to-noise ratio (CNR) were used to evaluate the noise level. ResultsThe 15th percentile of the lung CT histogram showed the smallest difference between full- and low-dose CT when applying the BM3D filter, and the highest difference between full- and low-dose CT without filters (full-dose = − 926.28 ± 0.32, BM3D = − 926.65 ± 0.32, and low-dose = − 959.43 ± 0.95) (p < 0.05). The COV was smallest when applying the BM3D filter, whereas the CNR was the highest (p < 0.05). ConclusionsThe results of the study prove that the BM3D filter can reduce image noise while increasing the reproducibility of the lung density, even for low-dose chest CT.

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.

Preoperative Nonselective Chest Computed Tomography Prior to Primary Cardiac Surgery Results in Meaningful Change to Surgical Management: Systematic Review and Pooled Prevalence Meta-Analysis

Routine screening chest computed tomography (CT) prior to primary cardiac surgery is advocated by some surgeons due to the purported benefits of identifying significant aortic calcification that impacts ongoing management, such as performing anaortic off-pump surgery or adjusting cannulation strategy. Additionally, axial imaging can identify incidental findings that may require concomitant or staged procedures such as ascending aortic dilatation or pulmonary lesions. The objective of this study was to quantify the impact that nonselective chest CT prior to primary cardiac surgery had on subsequent management. A systematic review and pooled prevalence meta-analyses were performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Included studies performed non-selective chest CT prior to primary cardiac surgery. A total of eight studies, including 2,250 patients were included. The rate of mortality and stroke was low (1% and 2%, respectively). Calcification of the ascending aorta was identified in 15% of patients (95% confidence interval [CI] 5.0-26.0). A significant change to the surgical plan such as cannulation strategy, off-pump surgery, cancellation, or an additional procedure was required in 7% (95% CI 2.0-12.0). Clinically relevant incidental findings requiring in-patient management or follow-up were identified in 10% (95% CI 6.0-14.0). Nonselective CT chest prior to primary cardiac surgery identifies clinically relevant findings that result in a modification of the surgical plan in a significant population of patients to address the risk of stroke associated with aortic calcification as well as the identification of important incidental findings such as pulmonary lesions.

Skeletal muscle quantity and quality evaluation in heart failure: comparing thoracic versus abdominopelvic CT approaches

Given the critical role of skeletal muscle in healthy aging, low muscle mass (myopenia) and quality (myosteatosis) can be used as predictors of poor functional and cardiometabolic outcomes. Myopenia is also a part of sarcopenia and malnutrition diagnostic criteria. However, there is limited evidence for using chest computed tomography (CT) to evaluate muscle health. We aimed to compare chest CT landmarks to the widely used L3 vertebra for single-slice skeletal muscle evaluation in patients with heart failure (HF). Patients admitted for acute decompensated HF between January 2017 and December 2018 were retrospectively analyzed. Body composition measurements were made on CT of the chest and abdomen/pelvis with or without contrast one month before discharge. Skeletal muscle index (SMI) and intermuscular adipose tissue percentage (IMAT%) were calculated at several thoracic levels (above the aortic arch, T8, and T12) and correlated to the widely used L3 level. A total of 200 patients were included, 89 (44.5%) female. The strongest correlation of thoracic SMI (for muscle quantity) and IMAT% (for muscle quality) with L3 was at the T12 level (r = 0.834, p < 0.001 and r = 0.757, p < 0.001, respectively). Cutoffs to identify low muscle mass for T12 SMI (derived from the lowest sex-stratified L3 SMI tertile) were 31.1 cm²/m² in men and 26.3 cm²/m² in women. SMI and IMAT% at T12 had excellent correlations with the widely used L3 level for muscle quantity and quality evaluation in patients with HF.

Recent symptomatic Omicron infection reduced COVID-19 pneumonia risk during reinfection: A computed tomography–based cohort study

ObjectivesSARS-CoV-2 infection could cause persistent lung injury or indicate potential genetic susceptibilities. Although infection-elicited hybrid immunity could protect against severe COVID-19, it remains unknown whether recent infection could reduce pneumonia risk during reinfection due to insufficient viral and chest computed tomography (CT) screening. MethodsA total of 15,598 patients, 96% fully vaccinated and 52% boosted, from Xiangyang, China, who had symptomatic COVID-19 and chest CT scans during the first Omicron BF.7 wave in December 2022 to January 2023, were followed through the second Omicron XBB.1.5 wave between May and August 2023. A total of 17,968 second-wave patients with COVID-19 with chest CT scans but without previous symptomatic COVID-19 were enrolled as first-time infection controls. ResultsA total of 19.6% (3,061 of 15,598) first-wave patients were diagnosed with pneumonia. Among second-wave reinfected patients, only 0.2% (four of 2202) developed pneumonia, which was lower than the 1.7% (311 of 17,968) pneumonia prevalence among the second-wave first-time patients, with an adjusted relative risk of 0.11 (95% confidence interval: 0.04-0.29). A total of 1.3% (40 of 3,039) first-wave pneumonia survivors showed residual abnormal patterns in follow-up CT scans within 8 months after pneumonia diagnosis. ConclusionsIn a highly vaccinated population, previous symptomatic Omicron infection within 8 months reduced pneumonia risk during reinfection. Uninfected individuals might need up-to-date vaccination to reduce pneumonia risk.

Chest Computed Tomography Severity Score to Predict Outcome of Patients with COVID 19

Abstract Background The coronavirus disease 2019 (COVID-19) is an acute infectious pneumonia caused by a severe acute respiratory syndrome-coronavirus-2. Some studies have suggested that C-reactive protein, lymphocyte count, and features from CT scoring as predictors of severity and prognosis of COVID-19. Non-contrast chest computed tomography (CT) scan was found to be a useful diagnostic instrument for screening COVID-19 pneumonia. This score uses lung opacification as a surrogate for extension of the disease in the lungs. Aim To assess the prognostic value of chest CT severity score (CSS) to predict the severity of symptoms and outcomes among patients with typical CT findings. Subject and Methods This Prospective Observational study was conducted at Radiology department, faculty of medicine, Ain Shams University on 94 patients. Results There is a significant difference between the groups regarding symptoms severity. there is no significant difference between the groups regarding CT findings. left lung severity scores and total severity score were significantly higher among poor prognosis patients compared to good prognosis patients. mortality rate was significantly higher among poor prognosis patients compared to good prognosis patients. severity score was significantly higher among severe symptoms patients compared to mild symptoms patients in good prognosis patients. Conclusion The current study showed that CT images and CT-severity scores can predict ICU admission and mortality in patients with COVID-19 pneumonia. Clinicians and radiologists can use the CT-severity score as a measure of disease severity and an indicator of poor prognosis, including the need for mechanical ventilation. Also, our findings showed the superiority of CT findings over other clinical information and co-morbidities in predicting the short-term outcome.

Images of Chest Computer Tomography (CT) and Radiation (X-ray) Demonstrating Clinical Manifestations of COVID-19: Review Article

Apart from reverse-transcription polymerase chain reaction (RT-PCR) testing, chest radiographs (CXR) and computed tomography (CT) scans were employed as crucial diagnostic methods for detecting the 2019 new coronavirus disease (COVID-19). Our objective is to examine three notable COVID-19 instances from patients across the globe, along with their CXR and CT data. The evaluation of the imaging characteristics of the reported instances was the primary objective of a methodical examination of the literature. We located more than several articles that had been published between 2020 and 2023. After the papers were examined, three major cases were chosen, including a COVID-19 assessment of imaging features (chest X-ray and CT scan). Corona viral diseases (COVID-19) pose a significant risk to healthcare facilities, especially when the patient has additional medical issues. It is challenging to understand the various chest radiography results because of the use of specialized and ambiguous terminology such as “airspace disease”, “pneumonia”, “infiltrates”, “patchy opacities”, and “hazy opacities”. The current investigation considered peer-reviewed case reports with Images features. Study designs, including reporting cases, were considered for imaging feature analysis.

Changes in Epicardial Adipose Tissue Assessed by Chest CT in Breast Cancer Patients Receiving Adjuvant Chemotherapy with Anthracyclines and Trastuzumab.

Cardiotoxicity (CTX) induced by adjuvant chemotherapy is a significant factor that impacts the prognosis and quality of life in breast cancer (BC) patients. In this study, we aimed to investigate the changes in epicardial adipose tissue (EAT) before and after treatment in BC patients who received anthracyclines adjuvant chemotherapy protocol (AC-T) and anthracyclines combined with trastuzumabadjuvant chemotherapy protocol (AC-TH). Additionally, we assessed whether there were any differences in the changes in EAT between the two groups of patients. Our objective was to examine the effects of anthracyclines and trastuzumab on EAT and determine the potential role of EAT changes on CTX. We reviewed female BC patients who were treated with adjuvant chemotherapy protocols of AC-T and AC-TH, all of whom underwent baseline (T0) and follow-up (T1) chest computed tomography (CT) and echocardiography. A cohort of healthy women, matched in age, underwent two chest CTs. EAT was quantified on chest CT using semi-automated software. CTX was defined as a 10% reduction in left ventricular ejection fraction (LVEF) from baseline, with an absolute value of 53%. A total of 41 BC patients were included in the study, with 23 patients in the AC-T group and 18 patients in the AC-TH group. Additionally, 22 healthy females were included as the normal group. None of the BC patients developed CTX after chemotherapy. The age did not differ significantly between the normal group and the AC-T group (p = 0.341) or the AC-TH group (p = 0.853). Similarly, the body mass index (BMI) of the normal group was comparable to that of the AC-T group (p = 0.377, 0.346) and the AC-TH group (p = 0.148, 0.119) before and after chemotherapy. The EAT volume index (mL/kg/ ) was significantly higher in both the AC-T group (5.11 1.85 vs. 4.34 1.55, p 0.001) and the AC-TH group (4.53 1.61 vs. 3.48 1.62, p 0.001) at T1 compared with T0. In addition, both the AC-T group (-72.95 5.01 vs. -71.22 3.91, p = 0.005) and the AC-TH group (-72.55 5.27 vs. -68.20 5.98, p 0.001) exhibited a significant decrease in EAT radiodensity (HU) at T1 compared to T0. However, there was no significant difference observed in the normal group. At T0, no difference was seen in EAT volume index (4.34 1.55 vs. 3.48 1.62, p = 0.090) and radiodensity (-71.22 3.91 vs. -68.20 5.98, p = 0.059) between the AC-T and AC-TH groups. Similarly, at T1, there was still no significant difference observed in the EAT volume index (-5.11 1.85 vs. 4.53 1.61, p = 0.308) and radiodensity (-72.95 5.00 vs. -72.54 5.27, p = 0.802) between the two groups. BC patients who underwent AC-T and AC-TH adjuvant chemotherapy protocols demonstrated a significant rise in the volume index of EAT, along with a substantial reduction in its radiodensity post-chemotherapy. These findings indicate that alterations in EAT could potentially aid in identifying cardiac complications caused by chemotherapeutic agents and remind clinicians to focus on changes in EAT after adjuvant chemotherapy in BC patients to prevent the practical occurrence of CTX.

Subchronic particulate matter exposure underlying polyhexamethylene guanidine phosphate–induced lung injury: Quantitative and qualitative evaluation with chest computed tomography

Our study was to explore the effects of subchronic particulate matter (PM) exposure on lung injury induced by polyhexamethylene guanidine phosphate (PHMG-p) in a rat model. Specifically, we investigated pulmonary inflammation, fibrosis, and tumor formation using chest computed tomography (CT), and histopathologic examination. PHMG-p was administered intratracheally to 20 male rats. After an initial week of PHMG-p treatment, the experimental group (PM group) received intratracheal administration of PM suspension, while the control group received normal saline. This regimen was continued for 10 weeks to induce subchronic PM exposure. Chest CT scans were conducted on all rats, followed by the extraction of both lungs for histopathological analysis. All CT images underwent comprehensive quantitative and qualitative analyses. Pulmonary inflammation was markedly intensified in rats subjected to subchronic PM exposure in the PM group compared to those in the control. Similarly, lung fibrosis was more severe in the PM group as observed on both chest CT and histopathologic examination. Quantitative chest CT analysis revealed that the mean lesion volume was significantly greater in the PM group than in the control group. Although the incidence of bronchiolo-alveolar hyperplasia was higher in the PM group compared to the control group, this difference was not statistically significant. In summary, subchronic PM exposure exacerbated pulmonary inflammation and fibrosis underlying lung injury induced by PHMG-p.

Diagnosis and imaging of diaphragmatic eventration: A case report

Background: Diaphragmatic eventration is a rare disorder that is typically found by accident in asymptomatic patients with a raised hemidiaphragm on chest X-rays. Both acquired and developmental defects can cause diaphragmatic eventration. The imaging methods for diaphragmatic eventration are numerous. Chest radiography should be done when there is clinical suspicion; this can be further confirmed with a chest computed tomography (CT). Case presentation: We present a case of a 37 years old woman with a left sided diaphragm eventration presenting as dyspnea and epigastrical discomfort. The diagnosis was made with chest x-ray and then confirmed with a chest CT scans. Discussion: There are several modalities to choose in diaphragmatic imaging. Chest x-ray is the main imaging method for diagnosing diaphragm eventration, in rare cases, a eventration needs to be differentiated using CT or MRI. Other imaging methods such as fluoroscopy and ultrasonography may be used in some instances to assess diaphragm function. Conclusions: There are various methods available in the field of diaphragmatic imaging. Certain methods, like CT and plain chest radiographs, concentrate on the anatomic anomalies of the diaphragm that may indicate dysfunction. Some instruments, including fluoroscopy and ultrasonography, are more appropriate for functional imaging.

Characteristics of the epicardial adipose tissue measured by low-dose chest computed tomography according to the metabolic health/obesity status

BackgroundEpicardial adipose tissue (EAT) is associated with the development of cardiovascular disease and long-term survival. This study aimed to assess the characteristics of EAT according to the metabolic health and obesity status using low-dose chest computed tomography (CT). MethodsA total of 1074 asymptomatic adults who underwent a medical health check-up were enrolled. Subjects were categorized into the following four groups according to the metabolic health and obesity status: metabolically healthy non-obese (MHNO); metabolically unhealthy non-obese (MUNO); metabolically healthy obese (MHO); and metabolically unhealthy obese (MUO). EAT on low-dose chest CT was measured by using automatic, quantitative measurement software. ResultsMUO showed the highest EAT volume and lowest EAT radiodensity in comparison with MHNO (p < 0.001). The MUNO (n = 70), MHO (n = 259), and MUO (n = 231) groups had increased EAT volume (β [95 % CI], 37.65 [23.11,52.18], 56.79 [47.56,66.02], 84.85 [74.59,95.11] respectively, all p < 0.001), decreased EAT radiodensity (β [95 % CI], − 3.22 [− 4.59,− 1.85], − 4.48 [− 5.30,− 3.66], − 6.03 [− 6.90,− 5.16] respectively, all p < 0.001) in comparison with the MHNO (n = 514) group by using multivariable linear regression models. ConclusionsBoth metabolic abnormalities and obesity were closely associated with EAT characteristics. Characteristics of EAT are similar in MHO and MUNO. This finding suggests that MHO is not a favorable condition in terms of cardiac health, as assessed by the characteristics of EAT. The combination of obesity and metabolically unhealthy status has a synergistic adverse effect on EAT. Measurement of EAT could be a useful imaging biomarker for evaluation of an individual's metabolic health/obesity status.

Artificial intelligence-based quantification of COVID-19 pneumonia burden using chest CT

AbstractDuring the coronavirus disease 2019 (COVID-19) pandemic, artificial intelligence (AI) based software on chest computed tomography (CT) imaging has proven to have a valuable role in accelerating diagnosis and screening. The proposed AI-based tools proved to be rapid and reproducible techniques to guide patient management and treatment protocols. Although no specific guidelines exist, CT-imaging and clinical features are used for patient staging. To shed light on the role of AI techniques that have been developed in fighting COVID-19, in this review, studies investigating the usage of commonly used AI models on chest CT imaging for disease quantification and prognostication are collected.

Value of Hounsfield units measured by chest computed tomography for assessing bone density in the thoracolumbar segment of the thoracic spine.

A retrospective study. To investigate the correlation between Hounsfield unit (HU) values measured by chest computed tomography (CT) and dual-energy Xray absorptiometry (DXA) T-scores. HU-based thoracolumbar (T11 and T12) cutoff thresholds were calculated for a cohort of Chinese patients. For patients with osteoporosis, the incidence of fractures in the thoracolumbar segment is significantly higher than that in other sites. However, most current clinical studies have focused on L1. This retrospective study analyzed patients who underwent chest CT and DXA at our hospital between August 2021 and August 2022. Thoracic thoracolumbar segment HU values, lumbar T-scores, and hip T-scores were computed for comparison, and thoracic thoracolumbar segment HU thresholds suggestive of potential bone density abnormalities were established using receiver operating characteristic curves. In total, 470 patients (72.4% women; mean age, 65.5±12.3 years) were included in this study. DXA revealed that of the 470 patients, 90 (19%) had osteoporosis, 180 (38%) had reduced osteopenia, and 200 (43%) had normal bone mineral density (BMD). To differentiate osteoporosis from osteopenia, the HU threshold was established as 105.1 (sensitivity, 54.4%; specificity, 72.2%) for T11 and 85.7 (sensitivity, 69.4%; specificity, 61.1%) for T12. To differentiate between osteopenia and normal BMD, the HU threshold was 146.7 for T11 (sensitivity, 57.5%; specificity, 84.4%) and 135.7 for T12 (sensitivity, 59.5%; specificity, 80%). This study supports the significance of HU values from chest CT for BMD assessment. Chest CT provides a new method for clinical opportunistic screening of osteoporosis. When the T11 HU is >146.7 or the T12 HU is >135.7, additional osteoporosis testing is not needed unless a vertebral fracture is detected. If the T11 HU is <105.1 or the T12 HU is <85.7, further DXA testing is strongly advised. In addition, vertebral HU values that fall faster than those of the T11 and L1 vertebrae may explain the high incidence of T12 vertebral fractures.

Preoperative Prediction of Shock Impedance for Subcutaneous Implantable Cardioverter Defibrillator Using Chest Computed Tomography.

High shock impedance is associated with conversion failure among patients with subcutaneous implantable cardioverter defibrillators (S-ICD). Currently, there is no preoperative assessment method for predicting high shock impedance. This study examined the efficacy of chest computed tomography (CT) as a preoperative evaluation tool to assess the shock impedance of S-ICDs.Methods and Results: The amount of adipose tissue adjacent to the device and anteroposterior diameter at the basal heart region were measured preoperatively using chest CT. We examined the correlation between these measurements and shock impedance at the conversion test. We enrolled 43 patients with S-ICDs (mean [±SD] age 54±15 years; body mass index 23±4 kg/m2; PRAETORIAN score 30-270 points; amount of adipose tissue 1,250±716 cm3), who underwent intraoperative conversion tests by inducing ventricular fibrillation, which was terminated with a 65-J shock. A sufficient concordance correlation coefficient was observed between the shock impedance and the amount of adipose tissue (r=0.616, P<0.01) and anteroposterior diameter (r=0.645, P<0.01). In multiple regression analysis, the amount of adipose tissue (β=0.439, P=0.009) and anteroposterior diameter (β=0.344, P=0.038) were identified as independent predictive factors of shock impedance. The preoperative CT-measured amount of adipose tissue and basal heart anteroposterior diameter are independent predictors of shock impedance. These parameters may be more accurate in identifying higher shock impedance in patients with S-ICDs.

Effect of Model-Based Iterative Reconstruction on Image Quality of Chest Computed Tomography for COVID-19 Pneumonia.

This study aimed to compare the image quality of chest computed tomography (CT) scans for COVID-19 pneumonia using forward-projected model-based iterative reconstruction solution-LUNG (FIRST-LUNG) with filtered back projection (FBP) and hybrid iterative reconstruction (HIR). The CT images of 44 inpatients diagnosed with COVID-19 pneumonia between December 2022 and June 2023 were retrospectively analyzed. The CT images were reconstructed using FBP, HIR, and FIRST-LUNG-MILD/STANDARD/STRONG. The CT values and noise of the lumen of the main trachea and erector spine muscle were measured for each group. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective evaluations included overall image quality, noise, streak artifact, visualization of normal lung structures, and abnormal CT features. One-way analysis of variance was used to compare the objective and subjective indicators among the five groups. The task-based transfer function was derived for three distinct contrasts representing anatomical structures, lower-contrast lesion, and higher-contrast lesion. The results of the study demonstrated significant differences in image noise, SNR, and CNR among the five groups (P < 0.001). The FBP images exhibited the highest levels of noise and the lowest SNR and CNR among the five groups (P < 0.001). When compared to the FBP and HIR groups, the noise was lower in the FIRST-LUNG-MILD/STANDARD/STRONG group, while the SNR and CNR were higher (P < 0.001). The subjective overall image quality score of FIRST-LUNG-MILD/STANDARD was significantly better than FBP and FIRST-LUNG-STRONG (P < 0.001). FIRST-LUNG-MILD was superior to FBP, HIR, FIRST-LUNG-STANDARD, and FIRST-LUNG-STRONG in visualizing proximal and peripheral bronchovascular and subpleural vessels (P < 0.05). Additionally, FIRST-LUNG-MILD achieved the best scores in evaluating abnormal lung structure (P < 0.001). The overall interobserver agreement was substantial (intraclass correlation coefficient = 0.891). The task-based transfer function 50% values of FIRST reconstructions are consistently higher compared to FBP and HIR. The FIRST-LUNG-MILD/STANDARD algorithm can enhance the image quality of chest CT in patients with COVID-19 pneumonia, while preserving important details of the lesions, better than the FBP and HIR algorithms. After evaluating various COVID-19 pneumonia lesions and considering the improvement in image quality, we recommend using the FIRST-LUNG-MILD reconstruction for diagnosing COVID-19 pneumonia.

The association between computed tomography-based osteosarcopenia and osteoporotic vertebral fractures: a longitudinal study.

Osteoporosis and sarcopenia usually coexist in older population. The concept of osteosarcopenia has been proposed in recent years. However, studies on the relationship between osteosarcopenia and the risk of fracture are rare, and the association is unclear at present. This study aimed to investigate the association between osteosarcopenia evaluated based on chest computed tomography (CT) and osteoporotic vertebral fracture (OVF). This study recruited 7906 individuals aged 50 years and older who did not have OVFs and underwent chest CT for physical examination between July 2016 and September 2019. Subjects were followed up annually until June 2023. Osteosarcopenia was defined by a low muscle area of the erector spinae (< 25.4 cm2) and the bone attenuation (Hounsfield unit, HU < 135). Genant's grades were used to define OVFs. Control subjects were selected by Propensity Score Matching at a ratio 20:1. Cox proportional hazards models were used to assess the associations between osteosarcopenia and OVFs. Of the 7906 participants included, 95 had a new OVF within a median follow-up of 3 years. A total of 1900 control subjects were matched. Individuals in the osteosarcopenia group had a higher prevalence of spinal fractures than those in normal group (16.4% vs. 0.4%, P < 0.001). Osteosarcopenia was independently associated with OVF (adjusted hazard ratio (aHR): 12.67, 95% confidence interval (CI) 3.79-42.40) and severe OVF (aHR = 14.07, 95% CI 1.84-107.66). Similar trends were observed in males, females and those subjects aged older than 60 years. Osteosarcopenia had good predictive efficacy for OVF (area under the curve = 0.836). A nomogram was also developed for clinical application. Osteosarcopenia assessed based on chest CT was associated with OVF, and osteosarcopenia has good performance for vertebral fracture prediction.

Chest computed tomography findings among adult Aboriginal Australians with bronchiectasis in the Top End Northern Territory of Australia.

There is limited evidence in the literature illustrating chest computed tomography (CT) characteristics among adult Aboriginal Australians with bronchiectasis. This retrospective study evaluates the radiological characteristics of bronchiectasis in Aboriginal Australians residing in the Top End, Northern Territory of Australia. Patients aged >18 years with chest CT-confirmed bronchiectasis between 2011 and 2020 were included. Demographics and relevant clinical parameters were collected. Alongside confirming bronchiectasis, chest CT reports were assessed for (i) lobar location (ii) unilateral or bilateral involvement and (iii) bronchiectasis type when available. A total of 459 patients were identified with chest CT-confirmed bronchiectasis, with a median age of 47 years, and 55% were females. Bronchiectasis was predominantly recorded in the left lower lobe (LLL) (73%), followed by the right lower lobe (RLL) (62%) and the left upper lobe (LUL) was least common (22%). Females recorded the right middle lobe (RML) affected significantly more often than males (50 vs. 34%, P = 0.012). Bilateral involvement was common (74%), with the strongest pairwise correlation associated between the right upper lobe (RUL) and LUL (P < 0.001). Cylindrical (50%) and cystic (28%) types were most common. The RML and LLL showed positive correlation with cylindrical and LUL with cystic bronchiectasis. Neither lobar location nor bronchiectasis type showed any significant association with lung function parameters other than RML, Lingula and LUL involvement being associated with better percent predicted values of diffusing capacity for carbon monoxide. There were no significant associations between sputum culture and type or lobar locations of bronchiectasis except for non-Aspergillus fungus culture prevalence was higher with cystic or cylindrical types. The results of this study may be an avenue to develop CT bronchiectasis severity scale in the future specific for Aboriginal Australians.