Thoracic Computed Tomography Imaging Research Articles

Biophysical properties of alveolar surfactant in drever dogs with hunting associated pulmonary edema

BackgroundA syndrome of acute non-cardiogenic pulmonary edema associated with hunting is prevalent in the drever breed, but etiology of this syndrome is currently unknown. Alveolar surfactant has a critical role in preventing alveolar collapse and edema formation. The aim of this study was to investigate, whether the predisposition to hunting associated pulmonary edema in drever dogs is associated with impaired biophysical properties of alveolar surfactant. Seven privately owned drever dogs with recurrent hunting associated pulmonary edema and seven healthy control dogs of other breeds were included in the study. All affected dogs underwent thorough clinical examinations including echocardiography, laryngeal evaluation, bronchoscopy, and bronchoalveolar lavage (BAL) as well as head, neck and thoracic computed tomography imaging to rule out other cardiorespiratory diseases potentially causing the clinical signs. Alveolar surfactant was isolated from frozen, cell-free supernatants of BAL fluid and biophysical analysis of the samples was completed using a constrained sessile drop surfactometer. Statistical comparisons over consecutive compression expansion cycles were performed using repeated measures ANOVA and comparisons of single values between groups were analyzed using T-test.ResultsThere were no significant differences between groups in any of the biophysical outcomes of surfactant analysis. The critical function of surfactant, reducing the surface tension to low values upon compression, was similar between healthy dogs and affected drevers.ConclusionsThe etiology of hunting associated pulmonary edema in drever dogs is not due to an underlying surfactant dysfunction.

Determination of the timing for thoracic imaging prior to pulmonary metastasectomy: an analysis on surgical planning and lesion detection

Aims: The aim of this study is to reveal the relationship between the timing of thoracic computed tomography (CT) imaging conducted prior to surgery and the pre-surgical period in patients planned for pulmonary metastasectomy (PM), and to determine a safe pre-surgical timing for thoracic CT. Methods: This study is a retrospective cohort study examining the data of patients who underwent pulmonary metastasectomy (PM). The research includes 96 patients who underwent PM between January 2017 and July 2022. Patients’ demographic data, primary malignancy diagnoses, type of operation, sizes of masses requiring anatomical resection, the number of lesions detected in thoracic CT, the number of lesions identified during surgery, and the timing of thoracic tomography were recorded. The timing of thoracic CT imaging was compared with the number of lesions detected preoperatively and postoperatively. Results: The study included 96 patients, comprising 49 females and 47 males. The most common primary pathological diagnosis was colon cancer at 36.5%, followed by breast cancer at 12.5%. 66.6% of the patients were operated on with thoracotomy, 29.1% with video-assisted thoracoscopic surgery (VATS), and 4.2% with rethoracotomy. The average number of lesions detected in preoperative thoracic tomography was 1.67±0.96, while the average number of lesions detected during surgery was 2.03±1.41. In patient groups where thoracic CT was performed 10 days or less before the operation, no significant difference was found between the number of lesions detected during surgery and the number of lesions in the CT. However, in patients where thoracic CT was performed more than 10 days before the operation, the number of lesions detected during surgery was significantly higher than the number of lesions detected in the CT. Conclusion: In this research, it was concluded that for patients planned for PM, repeating thoracic CT after the 10th day following the initial detection of metastases in the pre-surgical phase may contribute to the detection of more lesions.

Impact of beam collimation of z-overscanning on dose to the lens and thyroid gland in paediatric thoracic computed tomography imaging.

Adaptive collimation reduces the dose deposited outside the imaged volume along the z-axis. An increase in the dose deposited outside the imaged volume (to the lens and thyroid) in the z-axis direction is a concern in paediatric computed tomography (CT). To compare the dose deposited outside the imaged volume(tothe lens and thyroid) between 40-mm and 80-mm collimation during thoracic paediatric helical CT. We used anthropomorphic phantoms of newborns and 5-year-olds with 40-mm and 80-mm collimation during helical CT. We compared the measured dose deposited outside the imaged volume using optically stimulated luminescence dosimeters (OSLD) at the surfaces of the lens and thyroid and the image noise between the 40-mm and 80-mm collimations. There were significant differences in the dose deposited outside the imaged volume (to the lens and thyroid) between the 40-mm and 80-mm collimations for both phantoms (P < 0.01). Compared with that observed for 80-mm collimation in helical CTscans of the paediatric thorax, the dose deposited outside the imaged volume (tothe lens and thyroid) was significantly lower in newborns and 5-year-olds with 40-mm collimation.

Pulmonary involvement in antineutrophil cytoplasmic antibody-associated vasculitides: A single center experience from Turkey.

Pulmonary involvement is an important cause of mortality and morbidity in antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV). In this study, we aimed to evaluate the type and frequency of pulmonary involvement and investigate the potential relationship between thorax computed tomography (CT) signs and other systemic clinical findings in AAV. A total of 63 patients over the age of 18 and diagnosed with AAV were included in this study. Thoracic CT imaging findings and clinical features of the patients at the time of diagnosis were retrospectively evaluated. The frequency and distribution of detected pathological findings on imaging according to disease types, in addition to the relationship of these findings with other systemic findings and disease severity, were analyzed. Of 63 patients, 50 (79.4%) had pulmonary symptoms at the time of presentation. Most frequently observed pulmonary finding of thorax CT was nodular opacity. Consolidation, cavitary nodules, bronchiectasis, emphysema and fibrotic sequelae change were more common in the patients with diagnosis of granulomatosis with polyangiitis. Honeycomb, atelectasis, interstitial pneumonia, pulmonary venous congestion and pleural effusion were more common in the patients with diagnosis of microscopic polyangiitis. Ground-glass appearance, central airway disease, peribronchovascular nodules, pericardial effusion and lymphatic adenomegaly (>10 mm) were more common in the patients with diagnosis of eosinophilic granulomatosis with polyangiitis. Interstitial lung disease, pulmonary hemorrhage and severe lung involvement were found significantly increased in patients with myeloperoxidase antibody (MPO)-ANCA positivity (P < 0.05). Lung involvement was detected in almost all of the patients with AAV. Both interstitial lung disease and severe lung involvement were more frequently found in patients with MPO-ANCA positivity compared to other patients. Pulmonary examination by an imaging technique in all patients with AAV may be useful to determine the vasculitis subtype and to determine the extent of the disease. Pulmonary involvement is quite common in AAV. Every patient with suspected AAV should be examined with imaging for lung involvement, even in the absence of respiratory symptoms. Severe pulmonary involvement is associated with the presence of severe disease and MPO-ANCA positivity.

Increased monocyte level is a risk factor for radiological progression in patients with early fibrotic interstitial lung abnormality.

BackgroundInterstitial lung abnormalities (ILA) are specific spatial patterns on computed tomography (CT) scan potentially compatible with early interstitial lung disease. A proportion will progress; management involves risk stratification and surveillance. Elevated blood monocyte levels have been shown to associate with progression of idiopathic pulmonary fibrosis. The aims of the present study were: 1) to estimate the proportion of “early fibrotic” (EF)-ILAs (reticular±ground-glass opacities, excluding traction bronchiectasis and honeycombing) on CT scans of patients attending all-indications thoracic CTs, and proportion demonstrating radiological progression; and 2) to explore association between peripheral blood leukocyte levels and ILA progression.MethodsWe analysed all thoracic CT reports in individuals aged 45–75 years performed between January 2015 and December 2020 in one large teaching hospital (Oxford, UK) to identify patient CT reports consistent with EF-ILA. CT-contemporaneous blood leukocyte counts were examined to explore contribution to progression and all-cause mortality, using multivariate Cox regression.Results40 711 patients underwent thoracic CT imaging during this period. 1259 (3.1%) demonstrated the EF-ILA pattern (mean±sd age 65.4±7.32 years; 735 (47.8%) male). EF-ILA was significantly associated with all-cause mortality (hazard ratio 1.87, 95% CI 1.25–2.78; p=0.002). 362 cases underwent at least one follow-on CT. Radiological progression was observed in 157 (43.4%) cases: increase in reticulation n=51, new traction bronchiectasis n=84, honeycombing n=22. Monocyte count, neutrophil count, monocyte:lymphocyte ratio, neutrophil:lymphocyte ratio and “systemic inflammatory response index” were significantly associated with radiological progression.Conclusion3.1% of subjects requiring thoracic CT during a 6-year period demonstrated EF-ILA. Monocyte levels and blood leukocyte-derived indexes were associated with radiological progression and could indicate which patients may require closer follow-up.

Diagnostic Performance of Radiology Residents in Thoracic CT Imaging in Emergency Radiology During The COVID-19 Pandemic

During the COVID-19 pandemic, the workload of all radiologists and radiology residents, as well as other clinical physicians, has increased. This study aims to determine the diagnostic performance of radiology residents, who effectively contribute to the diagnosis of COVID-19. The thoracic Computed Tomography (CT) images of 135 patients aged 20-83 diagnosed with COVID-19 were evaluated retrospectively by five radiology residents and a radiologist with 10 years of experience. The diagnostic performance of the radiology residents in evaluating COVID-19 was assessed according to their year of residency and the patients' age and gender. Receiver Operating Characteristic (ROC) curve analysis was performed to determine the sensitivity and specificity of radiology residents. The radiology residents' performance in determining COVID-19 using CT findings was evaluated as follows: sensitivity 97.22%, specificity 88.89%, positive predictive value 90.91%, negative predictive value 96.55%, and accuracy 93.33%. According to the year of residency, the sensitivity and specificity of the radiology residents in determining COVID-19 using CT images were between 92.3% and 100%, and 71.43% and 100%, respectively. The high sensitivity and specificity of radiology residents in evaluating thoracic CT images for COVID-19 diagnosis indicate that radiologists are as important as clinical physicians in the diagnosis of COVID-19.

Computed Tomography of the Chest as a Screening Tool for Low Bone Mineral Density.

Computed tomography (CT) Hounsfield units (HU) recently emerged as a promising screening tool for low bone mineral density (BMD). We hypothesized that CT HU measurements of the thoracic spine would significantly and positively correlate with dual X-ray absorptiometry (DXA) BMD scans of the femoral neck. The study included patients with DXA scans and thoracic CT scans at the Walter Reed National Military Medical Center. One author, blinded to the DXA scans, measured HU from the cancellous bone in T4 vertebrae. Another author statistically compared femoral neck DXA T-scores to the CT HU measurements. The study included 145 patients with CT scans and femoral neck DXAs. The osteoporotic and osteopenic groups had a significant difference in HU measurements compared to the normal group within the study (P < .0001 and .002, respectively). A low BMD screening value of 231 HU provided a sensitivity of 90.1% and negative predictive value of 85.7%. Thoracic vertebrae HU measurements correlate with a low BMD of the femoral neck as determined by DXA T-scores. A high sensitivity and negative predictive value was achieved with a screening value of 231 HU. Utilization of chest or thoracic spine CT imaging as a screening method provides a quick and available screening tool for assessing low BMD in patients with these scans.Level of Evidence: III (Diagnostic).

Reformatted thoracic computed tomography imaging findings of an internal laryngocoele.

Reformatted thoracic computed tomography imaging findings of an internal laryngocoele.

The relationship between positivity for COVID-19 RT-PCR and symptoms, clinical findings, and mortality in Turkey

ABSTRACT Introduction: This study aimed to assess the correlation between nucleic acid amplification test (real-time reverse transcription-polymerase chain reaction, RT-PCR) positivity of patients presenting with suspected COVID-19 and pneumonic infiltration consistent with COVID-19-specific pneumonia diagnosis on thoracic computed tomography (CT), with symptoms, laboratory findings, and clinical progression. Methods: The study included 286 patients (female:male 131:155; mean age, 53.3 ± 17.9 years) who were divided into two groups according to their RT-PCR test results. The symptoms, laboratory examinations, clinical findings, and thoracic CT imaging of the patients were evaluated. Results: While the physical examination, comorbidities, and total CT scores were similar between the groups, taste/smell abnormalities were observed more frequently in the PCR-positive group. The use of moxifloxacin, lopinavir/ritonavir, and tocilizumab was higher in the PCR-positive group (p = 0.016, p < 0.001, and p = 0.002, respectively). The duration of hospitalization, intensive care requirement, and mortality rate of the studied groups did not differ between the groups. Conclusions: Among patients presenting with suspected COVID-19 and pneumonic infiltration consistent with COVID-19 on thoracic CT, the symptoms, physical examination, total CT scores, duration of hospitalization, intensive care requirement, and mortality rate were similar between RT-PCR-positive and RT-PCR-negative patients. However, PCR-positive patients appeared to require more specific treatments.

Evaluation of intrahepatic manifestation and distant extrahepatic disease in alveolar echinococcosis.

BACKGROUNDThe main endemic areas of alveolar echinococcosis (AE) are in Central Europe and Western China. Both the infiltration of intrahepatic vascular and bile duct structures as well as extrahepatic disease can lead to further complications and may increase morbidity in patients with AE.AIMTo evaluate vascular/biliary involvement in hepatic AE and its distant extrahepatic disease manifestations in an international collective was the aim.METHODSConsecutively, five experienced examiners evaluated contrast-enhanced abdominal computed tomography (CT) scans for 200 patients with hepatic AE of each of four locations (n = 50) in Germany, France and China. Therefore, we retrospectively included the 50 most recent abdominal contrast-enhanced CT examinations at each center, performed because of hepatic AE from September 21, 2007 to March 21, 2018. AE liver lesions were classified according to the echinococcosis multilocularis Ulm classification for CT (EMUC-CT). Distant extrahepatic manifestations were documented either by whole body positron emission tomography–CT or with the addition of thoracic CT and cranial magnetic resonance imaging. Vascular/biliary involvement of the hepatic disease as well as the presence of distant extrahepatic manifestations were correlated with the EMUC-CT types of liver lesion. Statistical analysis was performed using SAS Version 9.4 (SAS Institute Inc., Cary, NC, United States).RESULTSDistant extrahepatic AE manifestations were significantly more frequent in China than in Europe (P = 0.0091). A significant relationship was found between the presence of distant extrahepatic disease and AE liver lesion size (P = 0.0075). Vascular/biliary structures were involved by the liver lesions significantly more frequently in China than in Europe (P < 0.0001), and vascular/biliary involvement depended on lesion size. Different morphological types of AE liver lesions led to varying frequencies of vascular/biliary involvement and were associated with different frequencies of distant extrahepatic manifestations: Vascular/biliary involvement as a function of lesions primary morphology ranged from 5.88% of type IV liver lesions to 100% among type III lesions. Type IV differed significantly in these associations from types I, II, and III (P < 0.0001). With respect to extrahepatic disease, the primary morphology types IV and V of liver lesions were not associated with any case of distant extrahepatic disease. In contrast, distant extrahepatic manifestations in types I–III were found to varying degrees, with a maximum of 22% for type III.CONCLUSIONDifferent CT morphological patterns of hepatic AE lesions influence vascular/biliary involvement and the occurrence of distant extrahepatic manifestations. There are intercontinental differences regarding the characteristics of AE manifestation.

Can computerized tomography Hounsfield unit values be useful in the differential diagnosis of pleural effusion?

Introduction: We aimed to investigate the efficacy of Hounsfield unit (HU) attenuation measured on computed tomography (CT) as a non-invasive method for pleural effusion characterization. Methods: Patients with pleural effusion who underwent thoracic CT imaging and thoracentesis within a maximum of three days were included in this retrospective study (15 transudate and 36 exudate). By drawing a circular region of interest (ROI) on the section with the thickest pleural effusion in terms of anteroposterior diameter in the upper-medial-lower zone on axial images, a total of three HU values, one from each level, were averaged. An independent t-test was applied to the CT attenuation (HU) values for the transudate-exudate differentiation. A receiver operating characteristic (ROC) analysis was then made. Results: The mean attenuation±standard deviation (minimum-maximum) value for the patients with transudate was 2.17±3.76 ((-7.5)-7.5) HU, whereas the mean HU value for the patients with exudate was 8.38±6.2 ((-6)-22). The independent t test made for the transudate-exudate differentiation revealed a statistically significant difference (P=0.001). In the ROC analysis carried out to determine the cut-off value of the attenuation value of pleural effusion in the transudate-exudate differentiation, the area under the curve was found to be 82.8%. When the cut-off value was taken as 2.75HU for the area under the curve, sensitivity was found to be 84%, and specificity was 60%. Conclusion: Although CT-HU values are statistically significant in the differential diagnosis of transudate-exudate, there is still a need to establish a correlation with other tomographic findings and clinical laboratory findings.

Delayed-Phase Enhancement for Evaluation of Malignant Pleural Mesothelioma on Computed Tomography: A Prospective Cohort Study

BackgroundRadiologic assessment of malignant pleural mesothelioma (MPM) on computed tomography (CT) imaging can be limited by similar attenuations of MPM and adjacent tissues. This can result in inaccuracies in defining the presence and extent of pleural tumor burden. We hypothesized that increasing the time delay for pleural enhancement will optimize discrimination between MPM and noncancerous tissues on CT. Here we conduct a prospective observational study to determine the optimal time delay for imaging MPM on CT. Patients and MethodsAdult MPM patients (n = 15) were enrolled in this prospective exploratory imaging trial. Patients with < 1 cm MPM thickness, prior pleurectomy, pleurodesis, pleural radiotherapy, or antiangiogenic therapy were excluded. All patients underwent a dynamically-enhanced CT with multiple time delays (0 - 10 minutes) after intravenous contrast administration. Tumor tissue attenuation was measured at each phase of enhancement. A qualitative assessment of tumor enhancement kinetics was also performed. The optimal phase of enhancement based on qualitative lesion conspicuity and quantitative tumor enhancement was then compared. ResultsMPM tumor enhancement was quantitatively and qualitatively increased at time delays beyond the conventional time delay for thoracic CT imaging (40-60 seconds). Patient tumor enhancement kinetics, displayed as the fraction of maximal tumor tissue attenuation as a function of time, revealed an optimal time delay of 230 to 300 seconds after intravenous contrast administration. There was an association between degree of tumor enhancement and subjective lesion conspicuity. ConclusionOptimal MPM contrast enhancement occurs at a later phase than typically acquired with conventional thoracic CT imaging.

Prevalence of pectus excavatum in an adult population-based cohort estimated from radiographic indices of chest wall shape.

Pectus excavatum is the most common chest wall skeletal deformity. Although commonly evaluated in adolescence, its prevalence in adults is unknown. Radiographic indices of chest wall shape were analyzed for participants of the first (n = 2687) and second (n = 1780) phases of the population-based Dallas Heart Study and compared to clinical cases of pectus (n = 297). Thoracic computed tomography imaging studies were examined to calculate the Haller index, a measure of thoracic axial shape, and the Correction index, which quantitates the posterior displacement of the sternum relative to the ribs. At the level of the superior xiphoid, 0.5%, 5% and 0.4% of adult Dallas Heart Study subjects have evidence of pectus excavatum using thresholds of Haller index >3.25, Correction index >10%, or both, respectively. Radiographic measures of pectus are more common in females than males and there is a greater prevalence of pectus in women than men. In the general population, the Haller and Correction indices are associated with height and weight, independent of age, gender, and ethnicity. Repeat imaging of a subset of subjects (n = 992) demonstrated decreases in the mean Haller and Correction indices over seven years, suggesting change to a more circular axial thorax, with less sternal depression, over time. To our knowledge, this is the first study estimating the prevalence of pectus in an unselected adult population. Despite the higher reported prevalence of pectus cases in adolescent boys, this study demonstrates a higher prevalence of radiographic indices of pectus in adult females.

Neurogenic pulmonary edema following seizures: A retrospective computed tomography study

IntroductionData on the frequency and clinical relevance of neurogenic pulmonary edema (NPE) following epileptic seizures are limited. The aim of the present study was to analyze computed tomography (CT) examinations in patients with previous seizures. MethodIncidence of NPE and related clinical factors were retrospectively assessed in patients admitted because of epileptic seizures who underwent thoracic CT imaging as part of emergency diagnostics. ResultsBetween January 2010 and January 2016, we included all patients admitted with the International Classification of Diseases (ICD) diagnosis code of epileptic seizure or epilepsy and who underwent CT imaging, including visualization of the lungs, as part of emergency diagnostics.Of the 47 included patients, 26 patients had suffered from generalized convulsive seizures (GCS), 17 patients had focal seizures with impaired and 4 without impaired consciousness. Signs of NPE were present in 5 out of 47 patients; all 5 patients had GCS prior to thoracic CT scan (i.e., 19% of patients with GCS). In four out of five cases, a single seizure was described; in one case, the seizure was only partially witnessed, but the indirect clinical signs strongly suggested a GCS.Related factors such as the initial respiratory rate or the initial pCO2 value were not significantly different in patients with and without signs of NPE. ConclusionsThe highly selected and biased patient group warrants caution in the interpretation of the study results. Our data, however, confirm that signs of NPE appear to be rather frequent in patients with GCS. Its clinical significance as regards morbidity and sudden death in epilepsy is discussed.

Derivation and validation of thoracic sarcopenia assessment in patients undergoing thoracic endovascular aortic repair

ObjectiveSarcopenia, as assessed by computed tomography (CT)-based measurements of muscle mass, is an objective and patient-specific indicator of frailty, which is an important predictor of operative morbidity and mortality. Studies to date have primarily focused on psoas-defined sarcopenia, which may not be valid among patients with thoracic aortic disease. Using psoas sarcopenia as the reference for sarcopenia, the purpose of this study was to create and to validate a new thoracic-level method of measuring sarcopenia as a novel method to assess frailty among patients undergoing thoracic endovascular aortic repair. MethodsProspectively collected data of patients undergoing thoracic endovascular aortic repair for thoracic aortic dissection, aneurysm, or injury using a conformable thoracic graft were reviewed. Patients with preoperative abdominal and thoracic CT imaging were included. Thoracic muscle mass was measured on axial images at the T12 level using our newly established standardized computer-assisted protocol. Psoas sarcopenia was measured at the L3 level using standard methods. Optimal sex-specific diagnostic T12 measurements were determined by receiver operating characteristic (ROC) curve analysis. A subset of scans were reviewed in duplicate by two trained observers and intraobserver and interobserver reliability tested by intraclass correlation coefficient. Agreement between T12 and L3 sarcopenia was tested by Cohen κ (scale, 0-1). ResultsThere were 147 patients included for analysis, including 34 dissection, 80 trauma, and 33 aneurysm patients. ROC curve analysis yielded sarcopenic cutoff values of 106.00 cm2/m2 for women and 110.00 cm2/m2 for men at the T12 level. Based on ROC curve analysis, overall accuracy of T12 measurements was high (area under ROC curve, 0.91 for men and 0.90 for women). Quantitative interobserver and intraobserver reliability yielded excellent intraclass correlation coefficient values (>0.95). Qualitative interobserver reliability yielded nearly perfect Cohen κ values (>0.85). Qualitative intraobserver reliability of calculating sarcopenia at both the T12 and L3 levels was fair for both readers (0.361 and 0.288). There was additionally a general correlation between changes in muscle area at L3 with changes at T12 during 48 months. ConclusionsThoracic sarcopenia can be readily and reliably reproduced from CT-derived measurement of T12-level muscle area. This approach may be used as an alternative method to objectively define sarcopenia in patients without abdominal CT imaging. Future studies to assess the predictability of thoracic vs abdominal sarcopenia on postoperative outcomes will enhance the utility of these tools.

Comparison of ultrasonography and computed tomography in the determination of traumatic thoracic injuries

ObjectiveIn this study, the accuracy of bedside thoracic ultrasonography (TUSG) performed by emergency physicians with patients in the supine position was compared with that of thoracic computed tomography (TCT) for the determination of thoracic injuries due to trauma. MethodsPatients who suffered the multiple traumas, whose thoracic trauma was identified on physical examination or TCT imaging were included in the study. TUSG was performed following a physical examination by the emergency physician who managed the trauma patient. Subcutaneous emphysema, pneumothorax, pulmonary contusions (PCs), hemothorax, pericardial effusion and tamponade, sternal and clavicular fractures and rib fractures were identified by TUSG. TCT imaging was performed after the ultrasonography examination was completed. ResultsEighty-one patients were included in the study. TCT scans showed subcutaneous emphysema in 16 (19.8%) patients, pneumothorax in 21 (25.9%), PCs in 27 (33.3%), hemothorax in 20 (24.7%), sternum and clavicular fractures in 6 (7.4%) and rib fractures in 21 (25.9%). The sensitivity and specificity of ultrasonography varied for detecting the following pathologies: subcutaneous emphysema (56% and 95%), pneumothorax (86% and 97%), hemothorax (45% and 98%), PCs (63% and 91%), sternal fractures (83% and 97%), clavicular fractures (83% and 100%) and rib fractures (67% and 98%), respectively. ConclusionIn conclusion, ultrasound was found to be highly specific but only moderately sensitive for the identification of thoracic injuries.

Bronchoalveolar lavage affects computed tomographic and radiographic characteristics of the lungs in healthy dogs.

Bronchoalveolar lavage is a common diagnostic test for dogs with suspected pulmonary disease, however there is no published information on whether this procedure could affect the imaging characteristics of the lungs. Aims of this prospective experimental study were to describe computed tomography (CT) and radiographic features of the lungs after bronchoalveolar lavage in a sample of healthy dogs. Thoracic CT and radiographic images of eight healthy Beagles were acquired at the following time points: before bronchoalveolar lavage, immediately following bronchoalveolar lavage, and at 2, 4, 8, 12, and 24h following bronchoalveolar lavage. Lung consolidation or interstitial patterns were seen in CT and radiographic images immediately after the procedure. Radiographic lung patterns resolved within 2h and CT patterns resolved within 24h. Resolution of the CT pulmonary patterns in the ventral areas of the lungs was delayed compared to the dorsal areas. Mean CT imaging scores differed over time (P<0.001), while mean radiographic imaging scores did not differ over time. This study suggests that thoracic radiography and CT imaging assessments should precede bronchoalveolar lavage procedures if possible, or be performed at least 24h afterward.

Thoracic Computed Tomography Imaging in Dengue Fever: A Tertiary Experience in South Indian Population

Thoracic Computed Tomography Imaging in Dengue Fever: A Tertiary Experience in South Indian Population

Thoracic involvement in Erdheim-Chester disease: computed tomography imaging findings and their association with the BRAFV600E mutation.

To investigate the computed tomography (CT) thoracic findings in Erdheim-Chester disease (ECD) and evaluate the association of these findings with the BRAFV600E mutation. This was a prospective study of patients with ECD (n=61, men=46) who underwent thoracic CT imaging. CT examinations were independently interpreted by two experienced radiologists. Association of imaging findings with BRAFV600E was achieved via the Chi-square or Fisher's exact test and odds ratios (OR) with 95% confidence intervals (CI), as appropriate. Fifty-five ECD patients (90%) showed pulmonary findings, which included interlobular septal thickening (69%), pulmonary nodules (62%), airway thickening (13%) and ground glass opacities (36%). Pulmonary nodules were classified by the pattern of distribution: subpleural regions (36%), lung parenchyma (13%) and both regions (13%). Pleural and mediastinal involvement were present in 15% and 62% of cases, respectively. The most common mediastinal finding was sheathing of the right coronary artery (34%), followed by sheathing of the thoracic aorta (30%). The BRAFV600E mutation, positive in 31 patients, was associated with the frequency of sheathing of the coronary arteries (p = 0.01). Of the thoracic findings reported in this study, we found a statistically significant positive association between the BRAFV600E mutation and presence of coronary artery sheathing. • To assess the degree of thoracic involvement in ECD with CT. • BRAF V600E mutation has a high association with right coronary artery sheathing. • BRAF V600E genetic testing detects patients at high risk of developing RCA sheathing.

Metrics of lung tissue heterogeneity depend on BMI but not age.

Altered parenchymal microstructure and complexity have been observed in older age. How to distinguish between healthy, expected changes and early signs of pathology remains poorly understood. An objective quantitative analysis of computed tomography imaging was conducted to compare mean lung density, tissue density distributions, and tissue heterogeneity in 16 subjects, 8 aged >60 yr who were gender and body mass index matched with 8 subjects aged <30 yr. Subjects had never been smokers, with no prior respiratory disease, and no radiologically identified abnormalities on computed tomography. Volume-controlled breath hold imaging acquired at 80% vital capacity (end inspiration) and 55% vital capacity (end expiration) were used for analysis. Mean lung density was not different between the age groups at end inspiration ( P = 0.806) but was larger in the younger group at end expiration (0.26 ± 0.033 vs. 0.22 ± 0.026, P = 0.008), as is expected due to increased air trapping in the older population. However, gravitational gradients of tissue density did not differ with age; the only difference in distribution of tissue density between the two age groups was a lower density in the apices of the older group at end expiration. The heterogeneity of the lung tissue assessed using two metrics showed significant differences between end inspiration and end expiration, no dependence on age, and a significant relationship with body mass index at both lung volumes when heterogeneity was calculated using quadtree decomposition but only at end expiration when using a fractal dimension. NEW & NOTEWORTHY Changes to lung tissue heterogeneity can be a normal part of aging but can also be an early indicator of disease. We use novel techniques, which have previously not been used on thoracic computed tomography imaging, to quantify lung tissue heterogeneity in young and old healthy subjects. Our results show no dependence on age but a significant correlation with body mass index.