Affected Areas Of Lung Research Articles

Predictive Value of Simulated CT Radiomics Combined with Ipsilateral Lung Dosimetry Parameters for Radiation Pneumonitis in Patients with Esophageal Cancer: A Machine Learning-Based Retrospective Study.

To explore how non-surgical esophageal cancer patients can identify high-risk factors for radiation-induced pneumonitis after receiving radiotherapy. We retrospectively included 228 esophageal cancer patients who were unable to undergo surgical treatment but received radiotherapy for the first time. By retrospective analysis and identifying potential risk factors for symptomatic radiation-induced pneumonitis (ie ≥grade 2), as well as delineating the affected lung as an area of interest on localized CT and extracting radiomics features, along with extracting dosimetric parameters from the affected lung area. After feature screening, patients were randomly divided into training and testing sets in a 7-to-3 ratio, and a prediction model was established using machine learning algorithms. Finally, the receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were used to validate the predictive performance of the model. A total of 54 cases of symptomatic radiation pneumonitis occurred in this study, with a total incidence rate of 23.68%. The results of multivariate analysis showed that the occurrence of symptomatic radiation pneumonitis was significantly correlated with the mean lung dose (MLD), esophageal PTVD90, esophageal PTVV50, V5, V10, V15, and V20 in patients. The machine learning prediction model constructed based on candidate prediction variables has a prediction performance interval between 0.751 (95% CI: 0.700-0.802) and 0.891 (95% CI: 0.840-0.942) in the training and validation sets, respectively. Among them, the RFM algorithm has the best prediction performance for radiation-induced pneumonitis, with 0.891 (95% CI: 0.840-0.942) and 0.887 (95% CI: 0.836-0.938) in the training and validation sets, respectively. The combination of localization CT radiomics features and diseased lung dosimetry parameters has good predictive value for radiation-induced pneumonitis in esophageal cancer patients after radiotherapy. Especially, the radiation-induced pneumonitis prediction model constructed using RF algorithm can be more effectively used to guide clinical decision-making in esophageal cancer patients.

Comparison of the Discrimination Performance of AI Scoring and the Brixia Score in Predicting COVID-19 Severity on Chest X-Ray Imaging: Diagnostic Accuracy Study.

The artificial intelligence (AI) analysis of chest x-rays can increase the precision of binary COVID-19 diagnosis. However, it is unknown if AI-based chest x-rays can predict who will develop severe COVID-19, especially in low- and middle-income countries. The study aims to compare the performance of human radiologist Brixia scores versus 2 AI scoring systems in predicting the severity of COVID-19 pneumonia. We performed a cross-sectional study of 300 patients suspected with and with confirmed COVID-19 infection in Jakarta, Indonesia. A total of 2 AI scores were generated using CAD4COVID x-ray software. The AI probability score had slightly lower discrimination (area under the curve [AUC] 0.787, 95% CI 0.722-0.852). The AI score for the affected lung area (AUC 0.857, 95% CI 0.809-0.905) was almost as good as the human Brixia score (AUC 0.863, 95% CI 0.818-0.908). The AI score for the affected lung area and the human radiologist Brixia score had similar and good discrimination performance in predicting COVID-19 severity. Our study demonstrated that using AI-based diagnostic tools is possible, even in low-resource settings. However, before it is widely adopted in daily practice, more studies with a larger scale and that are prospective in nature are needed to confirm our findings.

Derivation and validation of novel integrated inpatient mortality prediction score for COVID-19 (IMPACT) using clinical, laboratory, and AI—processed radiological parameter upon admission: a multicentre study

Limited studies explore the use of AI for COVID-19 prognostication. This study investigates the relationship between AI-aided radiographic parameters, clinical and laboratory data, and mortality in hospitalized COVID-19 patients. We conducted a multicentre retrospective study. The derivation and validation cohort comprised of 512 and 137 confirmed COVID-19 patients, respectively. Variable selection for constructing an in-hospital mortality scoring model was performed using the least absolute shrinkage and selection operator, followed by logistic regression. The accuracy of the scoring model was assessed using the area under the receiver operating characteristic curve. The final model included eight variables: anosmia (OR: 0.280; 95%CI 0.095–0.826), dyspnoea (OR: 1.684; 95%CI 1.049–2.705), loss of consciousness (OR: 4.593; 95%CI 1.702–12.396), mean arterial pressure (OR: 0.928; 95%CI 0.900–0.957), peripheral oxygen saturation (OR: 0.981; 95%CI 0.967–0.996), neutrophil % (OR: 1.034; 95%CI 1.013–1.055), serum urea (OR: 1.018; 95%CI 1.010–1.026), affected lung area score (OR: 1.026; 95%CI 1.014–1.038). The Integrated Inpatient Mortality Prediction Score for COVID-19 (IMPACT) demonstrated a predictive value of 0.815 (95% CI 0.774–0.856) in the derivation cohort. Internal validation resulted in an AUROC of 0.770 (95% CI 0.661–0.879). Our study provides valuable evidence of the real-world application of AI in clinical settings. However, it is imperative to conduct prospective validation of our findings, preferably utilizing a control group and extending the application to broader populations.

Characteristics of patients with systemic sclerosis who develop interstitial lung disease

Systemic sclerosis associated-interstitial lung disease (SSc-ILD) show a high mortality. The factors associated SSc-ILD have shown variability in different populations. There are few studies in Mexican mestizos. To analyze the epidemiological, clinical and paraclinical factors associated with SSc-ILD. Cross-sectional study, where patients > 18 years of age with a diagnosis of SSc according to EULAR/ACR 2013 criteria and diagnosis of ILD by forced vital capacity (FVC) < 70% and > 5% of affected lung area on tomography were included. The strength of association of the factors for ILD was measured by odds ratio (OR) with 95% confidence intervals (95% CI). The significant variables were analyzed by multiple logistic regression with adjustment. Of the 80 patients with SSc, 38 (47.5%) had ILD. Risk factors such as smoking, higher activity index, lower FVC, anti-topoisomerase I antibodies, and protective factors such as a limited SSc, early capillaroscopic pattern, and anti-centromere antibodies (ACA) were associated with ILD. In the multivariate analysis, a higher activity index with OR 4.17, (95% CI 2.01-8.65) persisted as a risk factor, while ACA with OR 0.17, (95% CI 0.03-0.85) persisted as a protective factor associated with SSc-ILD. A higher index of activity and ACA persisted as factors associated with SSc-ILD.

Use of Nanostructured Silica SBA-15 as an Oral Vaccine Adjuvant to Control Mycoplasma hyopneumoniae in Swine Production

Mycoplasma hyopneumoniae is a difficult-to-control bacterium since commercial vaccines do not prevent colonization and excretion. The present study aimed to evaluate the performance of an orally administered vaccine composed of antigens extracted from Mycoplasma hyopneumoniae and incorporated into mesoporous silica (SBA-15), which has an adjuvant-carrier function, aiming to potentiate the action of the commercial intramuscular vaccine. A total of 60 piglets were divided into four groups (n = 15) submitted to different vaccination protocols as follows, Group 1: oral SBA15 + commercial vaccine at 24 days after weaning, G2: oral vaccine on the third day of life + vaccine commercial vaccine at 24 days, G3: commercial vaccine at 24 days, and G4: commercial vaccine + oral vaccine at 24 days. On the first day, the piglets were weighed and, from the third day onwards, submitted to blood collections for the detection and quantification of anti-Mycoplasma hyopneumoniae IgG. Nasal swabs were collected to monitor IgA by ELISA, and oropharyngeal swabs were used to assess the bacterial load by qPCR. Biological samples were collected periodically from the third day of life until the 73rd day. At 41 days of life, 15 individuals of the same age, experimentally challenged with an inoculum containing M. hyopneumoniae, were co-housed with the animals from groups (1 to 4) in a single pen to increase the infection pressure during the nursery period. At 73 days, all piglets were euthanized, and lungs were evaluated by collecting samples for estimation of bacterial load by qPCR. Quantitative data obtained from physical parameters and laboratory investigation were analyzed by performing parametric or non-parametric statistical tests. Results indicate that animals from G2 showed smaller affected lung areas compared to G3. Animals from G2 and G4 had a low prevalence of animals shedding M. hyopneumoniae at 61 days of age. Additionally, no correlation was observed between lung lesions and M. hyopneumoniae load in lung and BALF samples in animals that received the oral vaccine, while a strong correlation was observed in other groups. In the present study, evidence points to the effectiveness of the oral vaccine developed for controlling M. hyopneumoniae in pig production under field conditions.

Effects of Hyperoxia and Hyperoxic Oscillations on the Proteome of Murine Lung Microvascular Endothelium.

Patients presenting with insufficient tissue oxygenation and impaired lung function as in acute respiratory distress syndrome (ARDS) frequently require mechanical ventilation with supplemental oxygen. Despite the lung being used to experiencing the highest partial pressure of oxygen during healthy breathing, the organ is susceptible to oxygen-induced injury at supraphysiological concentrations. Hyperoxia-induced lung injury (HALI) has been regarded as a second hit to pre-existing lung injury and ventilator-induced lung injury (VILI) attributed to oxidative stress. The injured lung has a tendency to form atelectasis, a cyclic collapse and reopening of alveoli. The affected lung areas experience oxygen conditions that oscillate between hyperoxia and hypoxia rather than remaining in a constant hyperoxic state. Mechanisms of HALI have been investigated in many animal models previously. These studies provided insights into the effects of hyperoxia on the whole organism. However, cell type-specific responses have not been dissected in detail, but are necessary for a complete mechanistic understanding of ongoing pathological processes. In our study, we investigated the effects of constant and intermittent hyperoxia on the lung endothelium from a mouse by an in vitro proteomic approach. We demonstrate that these oxygen conditions have characteristic effects on the pulmonary endothelial proteome that underlie the physiological (patho)mechanisms.

Automatized lung disease quantification in patients with COVID-19 as a predictive tool to assess hospitalization severity.

The pandemic of COVID-19 led to a dramatic situation in hospitals, where staff had to deal with a huge number of patients in respiratory distress. To alleviate the workload of radiologists, we implemented an artificial intelligence (AI) - based analysis named CACOVID-CT, to automatically assess disease severity on chest CT scans obtained from those patients. We retrospectively studied CT scans obtained from 476 patients admitted at the University Hospital of Liege with a COVID-19 disease. We quantified the percentage of COVID-19 affected lung area (% AA) and the CT severity score (total CT-SS). These quantitative measurements were used to investigate the overall prognosis and patient outcome: hospital length of stay (LOS), ICU admission, ICU LOS, mechanical ventilation, and in-hospital death. Both CT-SS and % AA were highly correlated with the hospital LOS, the risk of ICU admission, the risk of mechanical ventilation and the risk of in-hospital death. Thus, CAD4COVID-CT analysis proved to be a useful tool in detecting patients with higher hospitalization severity risk. It will help for management of the patients flow. The software measured the extent of lung damage with great efficiency, thus relieving the workload of radiologists.

CT-Based Risk Stratification for Intensive Care Need and Survival in COVID-19 Patients-A Simple Solution.

We evaluated a simple semi-quantitative (SSQ) method for determining pulmonary involvement in computed tomography (CT) scans of COVID-19 patients. The extent of lung involvement in the first available CT was assessed with the SSQ method and subjectively. We identified risk factors for the need of invasive ventilation, intensive care unit (ICU) admission and for time to death after infection. Additionally, the diagnostic performance of both methods was evaluated. With the SSQ method, a 10% increase in the affected lung area was found to significantly increase the risk for need of ICU treatment with an odds ratio (OR) of 1.68 and for invasive ventilation with an OR of 1.35. Male sex, age, and pre-existing chronic lung disease were also associated with higher risks. A larger affected lung area was associated with a higher instantaneous risk of dying (hazard ratio (HR) of 1.11) independently of other risk factors. SSQ measurement was slightly superior to the subjective approach with an AUC of 73.5% for need of ICU treatment and 72.7% for invasive ventilation. SSQ assessment of the affected lung in the first available CT scans of COVID-19 patients may support early identification of those with higher risks for need of ICU treatment, invasive ventilation, or death.

Importance of Lung Ultrasound Follow-Up in Patients Who Had Recovered from Coronavirus Disease 2019: Results from a Prospective Study.

There is growing evidence regarding the imaging findings of coronavirus disease 2019 (COVID-19) in lung ultrasounds, however, their role in predicting the prognosis has yet to be explored. Our objective was to assess the usefulness of lung ultrasound in the short-term follow-up (1 and 3 months) of patients with SARS-CoV-2 pneumonia, and to describe the progression of the most relevant lung ultrasound findings. We conducted a prospective, longitudinal and observational study performed in patients with confirmed COVID-19 who underwent a lung ultrasound examination during hospitalization and repeated it 1 and 3 months after hospital discharge. A total of 96 patients were enrolled. In the initial ultrasound, bilateral involvement was present in 100% of the patients with mild, moderate or severe ARDS. The most affected lung area was the posteroinferior (93.8%) followed by the lateral (88.7%). Subpleural consolidations were present in 68% of the patients and consolidations larger than 1 cm in 24%. One month after the initial study, only 20.8% had complete resolution on lung ultrasound. This percentage rose to 68.7% at 3 months. Residual lesions were observed in a significant percentage of patients who recovered from moderate or severe ARDS (32.4% and 61.5%, respectively). In conclusion, lung injury associated with COVID-19 might take time to resolve. The findings in this report support the use of lung ultrasound in the short-term follow-up of patients recovered from COVID-19, as a radiation-sparing, easy to use, novel care path worth exploring.

New reference atlas for pulmonary fibrosis severity score in systemic sclerosis

New reference atlas for pulmonary fibrosis severity score in systemic sclerosis

Short-term Physiologic Consequences of Regional Pulmonary Vascular Occlusion in Pigs.

After pulmonary artery occlusion (mimicking a pulmonary embolism), perfusion is redistributed to the rest of the lung tissue, but the distribution of ventilation is uncertain. Data from anesthetized pigs (uninjured lungs) indicate that the perfusion is redistributed as suspected. Similarly, ventilation is redistributed from nonperfused to perfused lung tissue. This limits the increase in dead space and is accompanied by less density in the occluded lung. Acute unilateral pulmonary arterial occlusion causes ventilation-perfusion mismatch of the affected lung area. A diversion of ventilation from nonperfused to perfused lung areas, limiting the increase in dead space, has been described. The hypothesis was that the occlusion of a distal branch of the pulmonary artery would cause local redistribution of ventilation and changes in regional lung densitometry as assessed with quantitative computed tomography. In eight healthy, anesthetized pigs (18.5 ± 3.8 kg) ventilated with constant ventilatory settings, respiratory mechanics, arterial blood gases, and quantitative computed tomography scans were recorded at baseline and 30 min after the inflation of the balloon of a pulmonary artery catheter. Regional (left vs. right lung and perfused vs. nonperfused area) quantitative computed tomography was performed. The balloon always occluded a branch of the left pulmonary artery perfusing approximately 30% of lung tissue. Physiologic dead space increased (0.37 ± 0.17 vs. 0.43 ± 0.17, P = 0.005), causing an increase in PaCO2 (39.8 [35.2 to 43.0] vs. 41.8 [37.5 to 47.1] mmHg, P = 0.008) and reduction in pH (7.46 [7.42 to 7.50] vs. 7.42 [7.38 to 7.47], P = 0.008). Respiratory system compliance was reduced (24.4 ± 4.2 vs. 22.8 ± 4.8 ml · cm H2O, P = 0.028), and the reduction was more pronounced in the left hemithorax. Quantitative analysis of the nonperfused lung area revealed a significant reduction in lung density (-436 [-490 to -401] vs. -478 [-543 to -474] Hounsfield units, P = 0.016), due to a reduction in lung tissue (90 ± 23 vs. 81 ± 22 g, P < 0.001) and an increase in air volume (70 ± 22 vs. 82 ± 26 ml, P = 0.022). Regional pulmonary vascular occlusion is associated with a diversion of ventilation from nonperfused to perfused lung areas. This compensatory mechanism effectively limits ventilation perfusion mismatch. Quantitative computed tomography documented acute changes in lung densitometry after pulmonary vascular occlusion. In particular, the nonperfused lung area showed an increase in air volume and reduction in tissue mass, resulting in a decreased lung density.

The Correlation between Chest X-ray Scores and the Clinical Findings in Children and Adults with Mycoplasma pneumoniae Pneumonia.

Objective To compare the radiological and laboratory data of children and adults with Mycoplasma pneumoniae pneumonia (MPP) and to evaluate the correlation between the total affected lung area and the clinical findings. Methods We retrospectively examined the data from MPP patients who visited our hospital during the period from April 2006 to July 2014. All data were retrieved at the time of the diagnosis of MPP and were analyzed to investigate the correlation between the clinical findings and the total affected lung area using a chest X-ray scoring system. Results We identified 71 children and 54 adults with MPP. The incidence of consolidation, which was the most common chest X-ray finding in both groups, was similar (children: n = 62, 87.3%; adults: n = 45, 83.3%). In contrast, air bronchogram, bronchial thickening, and atelectasis were observed significantly more frequently among children than among adults. In both groups, a chest X-ray scoring system revealed a zonal predominance of the affected area (middle-to-lower lung fields). The body temperature and serum data such as the C-reactive protein level, white blood cell count, and lactate dehydrogenase level were significantly higher in the child group than in the adult group. The total score did not significantly correlate with the above-mentioned inflammatory markers or the presence of hypoxemia in either group. Conclusion This study showed the first evidence of a correlation between the extent of lung abnormalities on chest X-ray (calculated as a total score) and the clinical findings, including the presence of hypoxemia, in children and adults with MPP.

A Novel Reading Scheme for Assessing the Extent of Radiographic Abnormalities and Its Association with Disease Severity in Sputum Smear-Positive Tuberculosis: An Observational Study in Hyderabad/India.

BackgroundExisting reading schemes for chest X-ray (CXR) used to grade the extent of disease severity at diagnosis in patients with pulmonary tuberculosis (PTB) are often based on numerical scores that summate specific radiographic features. However, since PTB is known to exhibit a wide heterogeneity in pathology, certain features might be differentially associated with clinical parameters of disease severity.ObjectiveWe aimed to grade disease severity in PTB patients at diagnosis and after completion of DOTS treatment by developing a reading scheme based on five different radiographic manifestations and analyze their association with the clinical parameters of systemic involvement and infectivity.Methods141 HIV-negative adults with newly diagnosed sputum smear-positive PTB were enrolled in a prospective observational study in Hyderabad, India. The presence and extent on CXRs of five radiographic manifestations, i.e., lung involvement, alveolar infiltration, cavitation, lymphadenopathy and pleural effusion, were classified using the new reading scheme by using a four-quadrant approach. We evaluated the inter-reader reliability of each manifestation, and its association with BMI and sputum smear positivity at diagnosis. The presence and extent of these radiographic manifestations were further compared with CXRs on completion of DOTS treatment.ResultsAt diagnosis, an average lung area of 51.7% +/- 23.3% was affected by radiographic abnormalities. 94% of the patients had alveolar infiltrates, with 89.4% located in the upper quadrants, suggesting post primary PTB and in 34.8% of patients cavities were found. We further showed that the extent of affected lung area was a negative predictor of BMI (β value -0.035, p 0.019). No significant association of BMI with any of the other CXR features was found. The extent of alveolar infiltrates, along with the presence of cavitation, were strongly associated with sputum smear positivity. The microbiological cure rate in our cohort after 6 months of DOTS treatment was 95%. The extent of the affected lung area in these patients decreased from 56.0% +/- 21.5% to 31.0 +/- 20% and a decrease was also observed in the extent of alveolar infiltrates from 98.4% to 25.8% in at least one quadrant, presence of cavities from 34.8% to 1.6%, lymphadenopathy from 46.8% to 16.1%, and pleural effusion from 19.4% to 6.5%.ConclusionsWe established a new assessment scheme for grading disease severity in PTB by specifically considering five radiographic manifestations which were differently associated with the BMI and sputum smear positivity, changed to a different extent after 6 months of treatment and exhibited an excellent agreement between radiologists. Our results suggest that this reading scheme might contribute to the estimation of disease severity with respect to differences in disease pathology. Further studies are needed to determine a correlation with short and long-term pulmonary function impairment and whether there would be any benefit in lengthening or modulating therapy based on this CXR severity assessment.

Welders' siderosis: a retrospective cohort study on welder's pneumoconiosis patients with small round opacities on chest radiograph

To study the radiographycal changes and prognosis of welders' pneumoconiosis patients diagnosed within the last few years. Occupational hygienics data (including years on welding work, welding materials exposed to and work environment), symptoms, lung function test results and follow-up data of 136 welders' pneumoconiosis patients were collected retrospectively. The follow-up lasted up till June 30, 2014, with follow-up interval being one year. Chest radiographs were read/reviewed together by 3 senior experts experienced in pneumoconiosis diagnosing and shape and size of small opacity, overall profusion, affected lung zones and pneumoconiosis stages were all logged. Of all 136 pneumoconiosis cases, five were of stage II and 131 were stage I, and they had been engaged in welding work for 9.2±6.34 years. All patients were present with slight symptoms including coughing, chest distress and dyspnea, while their lung function remained normal. Small round opacities were found on chest radiographs of 88.9% of the 136 cases. Years of follow-up on 131 cases of stage I Welder's pneumoconiosis showed that irregular small opacities remained fundamentally unchanged, while small round opacities tended to gradually lessen instead of coalescence. Two years after primary diagnosing, the total affected lung zones of follow-up objects were noticed to start lessening, and reduced by 0.02 per patient among the 48 follow-up subjects. Of the 48 cases followed up up to six years after primary diagnosing, the affected lung zone number was reduced by 0.54 per patient while 4 cases (8%) went down to below stage I. As of the 36 patients followed up 10 years after after primary diagnosis, the number of affected lung areas decreased by 1.14, and 22% (8 cases) appeared less than stage I on chest radiograph. It seemed that the so-called welders' pneumoconiosis featuring small round opacities tended to get improved over time, which suggested the diagnosis of siderosis.

A computed tomography scoring system to assess pulmonary disease among premature infants.

High-resolution computed tomography (HRCT) is considered to be the best method for detailed pulmonary evaluation. The aim here was to describe a scoring system based on abnormalities identified on HRCT among premature infants, and measure the predictive validity of the score in relation to respiratory morbidity during the first year of life. Prospective cohort study in Instituto Fernandes Figueira, Fundação Oswaldo Cruz. Scoring system based on HRCT abnormalities among premature newborns. The affected lung area was quantified according to the number of compromised lobes, in addition to bilateral pulmonary involvement. Two radiologists applied the score to 86 HRCT scans. Intraobserver and interobserver agreement were analyzed. The score properties were calculated in relation to predictions of respiratory morbidity during the first year of life. Most of the patients (85%) presented abnormalities on HRCT, and among these, 56.2% presented respiratory morbidity during the first year of life. Scores ranged from zero to 12. There was good agreement between observers (intraclass correlation coefficient, ICC = 0.86, confidence interval, CI: 0.64-0.83). The predictive scores were as follows: positive predictive value 81.8%, negative predictive value 56.3%, sensitivity 39.1%, and specificity 90.0%. The scoring system is reproducible, easy to apply and allows HRCT comparisons among premature infants, by identifying patients with greater likelihood of respiratory morbidity during the first year of life. Its use will enable HRCT comparisons among premature infants with different risk factors for respiratory morbidity.

Spontaneous pulmonary interstitial emphysema in a term unventilated infant

Pulmonary interstitial emphysema (PIE) is a form of air block most frequently seen in ventilated preterm infants with severe lung disease; it is rarely reported in spontaneously breathing term infants. We report on an infant previously diagnosed with laryngomalacia and congestive heart failure and with evidence of antenatal stroke before the onset of pulmonary disease. He presented at 6 weeks of age with spontaneous pneumothorax. Focal cystic changes were seen on imaging studies of the lungs. There was no prior history of mechanical ventilation. Prior chest X-rays did not show cystic changes. He subsequently underwent resection of the affected lung areas. Pathologic examination revealed persistent PIE with cystic expansion, pleural blebs, and reactive pleuritis, as well as subpleural air-space enlargement. The patient did well postoperatively and was discharged home without further problems. This case demonstrates that PIE can occur in an infant without any history of mechanical ventilation, suggesting the need for a high index of suspicion for PIE, even in nonventilated and spontaneously breathing term neonates. PIE should be included in the differential diagnosis of cystic lung lesions in all young infants.

Whole body positron emission tomography (PET) for the detection of residual disease in gestational trophoblastic tumors (GTTs)

5109 Background: GTTs including invasive mole and choriocarcinoma are usually cured with chemotherapy assessed by a normalisation of the pregnancy hormone hCG. Relapses detected by a rising hCG can be cured by subsequent surgery/chemotherapy. Identification of the active site of recurrence for potential surgical resection can be difficult, particularly when there are mutliple lesions seen on CT/MRI. Whole-body 18fluorodeoxyglucose (18FDG)-PET may provide a solution to this problem and its value is examined here. Methods: The Charing Cross GTT database was screened and 9 patients were identified post- initial chemotherapy with rising or persistently elevated hCG who underwent CT/MRI and whole body 18FDG-PET to identify potential sites of active disease. The subsequent effect of surgery and or chemotherapy was assessed by the fall in hCG levels and the value of 18FDG-PET in management was determined. Results: 3 patients with residual lesions on CT/MRI which were active on PET, subsequently had surgery alone resulting in normalisation of hCG levels. One patient had a normal CT/MRI, but was PET positive in the lungs. The affected lung area was resected and the hCG normalised. Two patients had CT/MRI lesions not positive on PET. Further chemotherapy led to normalisation of hCG and CT/MRI. One patient with a lesion seen on CT and PET had resolution of these changes with chemotherapy. The 8th patient had a persistently raised hCG post-chemotherapy with a normal CT/MRI but was PET positive in the stomach, which resolved with chemotherapy. The 9th patient had a persistently raised serum hCG between 20–30iu/l, despite no lesion on CT/MRI or PET, and has remained well off treatment for 24 months. Conclusion: We report the largest series to date of the use FDG- PET scanning in GTT. PET scanning can be useful for confirming sites of active disease seen as lesions on CT/MRI scans. In two cases PET scanning found sites of disease not seen on conventional imaging. No significant financial relationships to disclose.

Effects of ammonium sulfate aerosol exposure on lung structure of normal and elastase-impaired rats and guinea pigs

Rats and guinea pigs, pretreated with intratracheally administered elastase or saline, were exposed to 1.03 mg/m 3 (NH 4) 2SO 4; MMAD, 0.42 μm. Identically treated controls were sham exposed. Measurements and evaluation of structural changes were conducted using morphometric techniques on SEM photographs and by applying subjective ratings. Pathology studies were conducted by light and electron microscopy. All examination methods confirmed elastase-induced emphysema, which was aggravated by (NH 4) 2SO 4 exposure in the rat. Ammonium sulfate exposure of saline-treated animals produced measurable degrees of enlargement of alveo i, and alveolar ducts and sacs. Electron microscopy revealed increased interstitial collagen in affected lung areas of elastase-treated, (NH 4) 2SO 4-exposed animals. Alveolar-pore size was significantly increased in elastase-treated animals (control and exposed) but not in saline-treated, exposed animals. The data suggest a possible difference between elastase and (NH 4) 2SO 4 in the mechanisms responsible for the increased diameter of alveolar structures. Hypertrophy and hyperplasia of nonciliated epithelial cells of the small airways and of the Type II alveolar cells were observed in otherwise untreated guinea pigs exposed to (NH 4) 2SO 4 but not in elastase-treated guinea pigs, nor in any of the rats.

Primer for Pulmonary Hygiene

Pulmonary hygiene is the easiest, safest, and cheapest way to prevent pulmonary complications or respiratory failure. It is a series of techniques to help a patient clear his lungs and bronchial airways of excess secretions. Pulmonary hygiene, or pulmonary toilet, is indicated for patients who have pneumonia and atelectasis: lung abscesses; obstructive ventilatory diseases like asthma, bronchitis, emphysema, and bronchiectasis; and for most all postoperative patients. Pulmonary hygiene generally consists of such measures as postural drainage, positioning to facilitate drainage of the various lung segments: cupping, or percussion, to affected lung areas; and deep breathing and coughing, which are the most important. Vibration of the chest wall and underlying structures through mechanical or manual means is not done