Radiographic Features for Predicting Smear-Negative Pulmonary Tuberculosis.

Background: Diagnosis of smear-negative pulmonary tuberculosis (TB) in some circumstances remains a challenge to physicians especially those working in limited-resource settings. Objective: To investigate and examine radiographic characters as a predictor of true diagnosis of pulmonary tuberculosis in patients with negative sputum smears. Material and Method: This retrospective cross-sectional study was conducted in patients with smear-negative pulmonary TB at Siriraj Hospital between January 2013 and June 2014. Patients with previous TB treatment, HIV co-infection, significant pleural effusion, and corticosteroid therapy equivalent to prednisolone greater than 15 mg/day were excluded. Demographic and clinical data were collected and radiographic features were reviewed and classified as active or inactive TB by a consensus of three independent reviewers. Various diagnostic parameters for true prediction of TB, as defined by culture confirmation and/or radiographic improvement, were then examined. Results: There were 122 patients during the study period, 65 (53%) were male, 27 (22%) were asymptomatic, 20 (16%) had extrapulmonary involvement, and eight (7%) had concomitant diabetes mellitus. TB was confirmed in 92 patients (75%), 72 had positive culture and 20 had radiographic improvement. Miliary nodules and cavitary lesions had high specificity (100% and 100%, respectively) and low sensitivity (9.8% and 13%, respectively) for prediction of true TB. Focal interstitial and alveolar opacities had high positive predictive value (79.5 and 85%) and modest accuracy (62.3 and 47.5%). Conclusion: Given that specific radiographic features are uncommon and non-specific features are common in smear-negative pulmonary tuberculosis, clinicians should supplement clinical symptoms, radiological features, and radiological responses with mycobacterium TB culture to verify diagnosis of TB.

Pathological confirmed diagnosis of asbestosis: the first case report in Thailand.

Asbestosis is an occupational lung disease defined as pulmonary fibrosis caused by asbestos. Asbestosis was previously reported in Thailand based on radiologic findings, which demonstrated interstitial lung with calcified pleural plaques, and the patient worked in a fiber cement factory. However there was some doubt about the diagnosis because clinical and radiological findings are nonspecific; there was no data support of asbestos exposure in the patient and no histologic confirmed diagnosis. Histologic diagnosis is most useful when an equivocal of ahistory of asbestos exposure in patients with interstitial lung diseases take place. The authors report a patient presenting with progressive dyspnea for 2 years. She worked in an electric, wire, mesh fan cover factory to check quality of protective wire mesh for 10 years until the factory was closed 6 years ago. This type of factory had never officially reported asbestos use. Her clinical manifestations and radiologic findings are compatible with interstitial lung disease. She subsequently underwent thoracotomy with wedge lung resection. Pathology revealed interstitial fibrosis with honeycombing. Asbestos bodies were found more than 10 per cm2 in the fibrosis. She was diagnosed asbestosis. The patient is suffering from dyspnea, severe hypoxemia and cor pulmonale. The patient is put on waiting lists for heart lung transplantation. The authors thus confirmed that asbestosis exists in Thailand. A policy to protect workers and people who may have risk of asbestos exposure is necessary, since diseases related to asbestos are incurable, but preventable.

Relationship between emphysema quantification and COPD severity.

OBJECTIVE: To determine the association between emphysema extent from high-resolution computed tomography (HRCT) and the physiological derangement in patients with chronic obstructive pulmonary disease (COPD). MATERIAL AND METHOD: A cross-sectional study was undertaken to quantify the emphysema severity in 23 COPD patients by automated HRCT scoring techniques. Correlation with phenotypic characters in term of exercise capacity [Modified Medical Research Council (mMRC) dyspnea scale, and 6-minute walk distance (6MWD)], pulmonary function testing [spirometry (forced expiratory volume in 1 second, FEV1 and forced vital capacity, FVC), and diffusing capacity (DLCO)], were then assessed. RESULTS: Nineteen patients were male and four were female, the mean age was 73 ± 8 years, with the mean FEV1 % predicted of 67.8 ± 25.4. Percentage of inspiratory emphysematous lung volume (%ELVi) had significant negative correlation with %FEV/FVC (r = -0.50, p = 0.016) and DLCO (r = 0.58, p = 0.011). Percentage of expiratory emphysematous lung volumes (%ELVe) also had the same correlation with %FEV/FVC (r = -0.58, p = 0.004) and DLCO (r = 0.48, p = 0.042). In addition, %ELVe also had significant negative correlation with 6MWD (r = 0.50, p = 0.016), but had significant positive correlation with mMRC scale (r = 0.53, p = 0.01). CONCLUSION: Severity of emphysema assessed by HRCT was well correlated with pulmonary function test results and exercise capacity. It can be used as one aspect ofphenotypic characters in patients with COPD,for designing personalize management plan.

Characteristics of culture-negative subclinical pulmonary tuberculosis: a single-center observation.

BACKGROUND: Little is known about culture-negative subclinical pulmonary tuberculosis (TB), and its diagnosis remains challenging. Therefore, this study aimed to identify the characteristics and the extent of disease associated with culture-negative subclinical pulmonary TB. METHODS: This retrospective cohort study was conducted on immunocompetent individuals with subclinical pulmonary TB at a university hospital in Thailand from January 2014 to December 2019. Subclinical pulmonary TB was diagnosed based on the presence of radiographic abnormalities consistent with TB in the absence of TB symptoms. All subjects demonstrated significant improvement or resolution of radiographic abnormalities following the completion of treatment. At least two negative sputum cultures were needed to fulfill the definition of culture-negative pulmonary TB. Data were analyzed using univariate and multiple logistic regression analyses to determine the characteristics of those with culture-negative subclinical pulmonary TB compared to culture-positive ones. RESULTS: Out of the 106 individuals identified with subclinical pulmonary TB, 84 met the criteria for inclusion in the analysis. The study found lower radiographic extent and increasing age were key attributes of culture-negative subclinical pulmonary TB. The odds ratios (95% confidence interval) were 7.18 (1.76 to 29.35) and 1.07 (1.01 to 1.13), respectively. They tend to have lower rates of bilateral involvement in both chest x-ray (8.5% vs. 32.0%, p=0.006) and computed tomography (15.4% vs. 42.9%, p=0.035). However, no other specific radiographic findings were identified. CONCLUSIONS: People with culture-negative subclinical pulmonary TB were likely to have less radiographic -severity, reflecting early disease. Nevertheless, no radiographic patterns, except for unilaterality, were related to culture-negative subclinical pulmonary TB.

Bacterial Coinfection and Superinfection in Respiratory Syncytial Virus-Associated Acute Respiratory Illness: Prevalence, Pathogens, Initial Antibiotic-Prescribing Patterns and Outcomes.

We aimed to determine the prevalence of bacterial coinfection (CoBact) and bacterial superinfection (SuperBact), the causative pathogens, the initial antibiotic-prescribing practice, and the associated clinical outcomes of hospitalized patients with respiratory syncytial virus-associated acute respiratory illness (RSV-ARI). This retrospective study included 175 adults with RSV-ARI, virologically confirmed via RT-PCR, during the period 2014-2019. Thirty (17.1%) patients had CoBact, and 18 (10.3%) had SuperBact. The independent factors associated with CoBact were invasive mechanical ventilation (OR: 12.1, 95% CI: 4.7-31.4; p < 0.001) and neutrophilia (OR: 3.3, 95% CI: 1.3-8.5; p = 0.01). The independent factors associated with SuperBact were invasive mechanical ventilation (aHR: 7.2, 95% CI: 2.4-21.1; p < 0.001) and systemic corticosteroids (aHR: 3.1, 95% CI: 1.2-8.1; p = 0.02). CoBact was associated with higher mortality compared to patients without CoBact (16.7% vs. 5.5%, p = 0.05). Similarly, SuperBact was associated with higher mortality compared to patients without SuperBact (38.9% vs. 3.8%, p < 0.001). The most common CoBact pathogen identified was Pseudomonas aeruginosa (30%), followed by Staphylococcus aureus (23.3%). The most common SuperBact pathogen identified was Acinetobacter spp. (44.4%), followed by ESBL-positive Enterobacteriaceae (33.3%). Twenty-two (100%) pathogens were potentially drug-resistant bacteria. In patients without CoBact, there was no difference in mortality between patients who received an initial antibiotic treatment of <5 days or ≥5 days.

Cost effectiveness of combined CT pulmonary angiography (CTPA) and indirect CTV in patient with intermediate to high probability for pulmonary embolism.

OBJECTIVE: Evaluate the cost effectiveness of combined CTPA and indirect CTV for evaluation of patients with intermediate to high probability for pulmonary embolism using Wells criteria. MATERIAL AND METHOD: One hundred cases with moderate to high probability for pulmonary embolism according to Wells criteria were prospectively collected between December 2007 and January 2010. Combined CTPA and indirect CTV were performed. Positive findings were including the visualization of filling defect within the pulmonary artery and/or deep venous system of the lower extremities. Negative findings were including no demonstrable of filling defect within pulmonary artery and deep venous system of lower extremity plus absence of clinical manifestation of pulmonary embolism and deep vein thrombosis during 3-month follow-up. RESULTS: One hundred cases including 31 men and 69 women with age range 16 to 95 years (mean = 61.8) were collected. Four cases were excluded according to non-opacified of the lower extremities veins. The authors found that 36 cases (38%) had pulmonary embolism, while 60 cases (62%) were negative for pulmonary embolism. For the group with positive pulmonary embolism, 11 cases (31%) did not have DVT while 25 (69%) case also had DVT as well. In the negative pulmonary embolism group, 49 (82%) did not have DVT but 11 (18%) were shown to have DVT. CONCLUSION: For 96 cases with intermediate to high probability of PE, the authors needed to spend 70,909 baht more per case for the extra-investigation (combined CTPA and indirect CTV) for early detection of DVT. By comparison of two workup strategies, combined CTPA and indirect CTV of the lower extremities and CTPA with direct CTV of the lower extremities, the expense for detecting DVT in patients who also have PE will be 31,200 baht per case. Clinicians can use this value to judge between the cost effectiveness of this investigation and the expense of longer hospitalization and medical expense for late complication of DVT which was frequently found in patients with PE. In additional, indirect CTV can increase diagnosis of deep vein thrombosis in non-PE case up to 30% in the present study.

Respiratory syncytial virus-associated acute respiratory illness in adult non-immunocompromised patients: Outcomes, determinants of outcomes, and the effect of oral ribavirin treatment.

BACKGROUND: Respiratory syncytial virus (RSV) is an increasingly common cause of respiratory illness in adult non-immunocompromised patients. Oral ribavirin was reported to improve outcomes of RSV infection in immunocompromised patients. This study aimed to determine the outcomes of non-immunocompromised patients hospitalized with RSV-associated acute respiratory illnesses (RSV-ARI), the factors independently associated with the outcomes and the effect of oral ribavirin treatment. METHODS: This retrospective, observational cohort study included 175 adults admitted to the hospital with virologically confirmed RSV-ARI during 2014-2019. Severe ARI was identified using Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS) criteria for severe community-acquired pneumonia. The primary outcome was all-cause mortality within 30 days after enrollment. A multivariable Cox model was performed to identify significant predictors of mortality. RESULTS: Mean age was 76 ± 12.7 years. Seventy-eight (44.6%) patients met the diagnostic criteria for severe ARI. Thirty-six (20.6%) patients required invasive mechanical ventilation, and 11 (6.3%) required vasopressor. Ninety-nine (56.6%) patients received oral ribavirin treatment, and 52 (29.7%) received systemic corticosteroids. Forty-one (23.4%) patients had evidence of bacterial infection. Overall mortality was 7.4%. Mortality among patients with non-severe ARI and severe ARI was 1.04% and 15.4%, respectively. Estimated glomerular filtration rate <50 ml/min/1.73 m2 , severe ARI, systemic corticosteroids, and bacterial infection were independently associated with higher risk of mortality. Treatment with oral ribavirin was the only factor associated with reduced mortality (adjusted HR: 0.19, 95% CI: 0.04-0.9, P = 0.03). CONCLUSION: RSV-ARI may result in significant mortality and health care utilization. Treatment with oral ribavirin may improve survival in these patients.

Comparison of low dose and standard dose MDCT in detection of metastatic pulmonary nodules.

OBJECTIVE: Compare low dose (50 mA) and standard dose (300 mA) MDCT in detection of metastatic pulmonary nodules in extrathoracic malignant patients in Siriraj hospital. MATERIAL AND METHOD: Prospectively, 58 patients underwent chest CT examinations by 64-slice MDCT in non-enhanced phase with a reduced tube current of 50 mA (low-dose CT (LDCT)), followed by contrast-enhanced phase with a standard tube current of 300 mA (Standard-dose CT (SDCT)). Otherparameter such as tube voltage 120 kVp, spiral pitch 0.984, and section thickness 1.25 mm, were kept constant. Four hundred twenty two nodules found by SDCT and 427 nodules found by LDCT were analyzed. RESULTS: The sensitivity of LDCT was 94.7% for all nodules, 79% for nodules < or =2 mm, 94.2% for nodules 2.1-3 mm, 97% for nodules 3.1-4 mm, and 100% for nodules 4.1-5 mm. Three types of nodules were found and classified as calcific nodule, non-calcific nodule, and ground-glass nodule of which sensitivity for detection in LDCT were 100% (p = 1.000), 95.9% (p = 0.337) and 77% (p = 0.581), respectively. Most common causes of discrepancy in SDCT were unseen nodules and in LDCT were end-on vessel nodules. Majority of discrepant nodules and retrospective nodules were < or =3 mm. Effective dose ranged from 0.78 mSv.-1.6 mSv in LDCT and 4.22-9.57 mSv in SDCT. CONCLUSION: There is no statistical difference in detection of metastatic pulmonary nodules by using low-dose and standard-dose CT images. Low-dose CT images can used to follow-up the treatment responsiveness of the known patient, diagnosed to have pulmonary metastasis.

Characteristics, complications, and mortality of respiratory syncytial virus compared with influenza infections in hospitalized adult patients in Thailand.

INTRODUCTION: RSV is increasingly recognized in adults. An improved understanding of clinical manifestations and complications may facilitate diagnosis and management. METHODS: This was a retrospective study of hospitalized patients aged ≥ 18 years with RSV or influenza infection at Siriraj hospital, Thailand between January 2014 and December 2017. RESULTS: RSV and/or influenza were detected by RT-PCR in 570 (20.1%) of 2836 patients. After excluding patients coinfected with influenza A and B (n = 5), and with influenza and RSV (n = 3), 141 (5.0%) RSV and 421 (14.8%) influenza patients were analyzed. Over the study period, RSV circulated during the rainy season and peaked in September or October. Patients with RSV were older than patients with influenza and presented significantly less myalgia and fever, but more wheezing. Pneumonia was the most common complication, occurring in 110 (78.0%) of RSV cases and in 295 (70.1%) of influenza cases (p = 0.069). Cardiovascular complications were found in 30 (21.3%) RSV and 96 (22.8%) influenza (p = 0.707), and were reasons for admission in 15 (10.6%) RSV and 50 (11.9%) influenza. The in-hospital mortality rates for RSV (17; 12.1%) and influenza (60; 14.3%) were similar (p = 0.512). CONCLUSIONS: In Thailand, RSV is a less common cause of adult hospitalization than influenza, but pulmonary and cardiovascular complications, and mortality are similar. Clinical manifestations cannot reliably distinguish between RSV and influenza infection; laboratory-confirmed diagnosis is needed.

Helpful CT findings for giving specific diagnosis of anterior mediastinal tumors.

OBJECTIVE: To characterize the CT features of common anterior mediastinal tumors and evaluate CT findings that may help in suggesting specific diagnosis among these tumors. MATERIAL AND METHOD: Fifty chest CT studies with pathological diagnosis of thymoma (n=28), mediastinal germ cell tumor (n=14) and lymphoma (n=8) were retrospectively reviewed by two radiologists who were blind to the pathological results. The CT findings of fat, cyst and calcification within the lesion, contrast enhancement, associated intrathoracic findings such as mediastinal invasion and lymph node enlargement were evaluated. RESULTS: Fat density within the mass was present in 57.1% with germ cell tumor which was significantly higher than other anterior mediastinal tumors (p < 0.05). The presence of associated mediastinal lymphadenopathy was significantly found in lymphoma (75.0%) compared to other tumors (p < 0.05). The other CT findings showed no significant difference among these diseases (p > 0.05). CONCLUSION: The CT findings that help in giving specific diagnosis of anterior mediastinal tumors which are fat attenuation and associated mediastinal lymphadenopathy. The presence off at attenuation is highly suggestive of germ cell tumor and anterior mediastinal mass associated with mediastinal lymphadenopathy elsewhere is indicative of lymphoma.

Clinical manifestations and outcomes of respiratory syncytial virus infection in adult hospitalized patients.

BACKGROUND: Respiratory syncytial virus (RSV) is an important virus found in adult hospitalized patients. OBJECTIVES: To study the clinical outcomes of hospitalized patients aged ≥ 15 years and diagnosed with RSV infection. STUDY DESIGN: Both retrospective and prospective cohort studies were conducted at a university hospital between May 2014 and December 2015. RESULTS: RSV was detected in 86 of 1562(5.5%) adult hospitalized patients suspected of respiratory viral infection. Sixty-nine patients were included in the study. RSV was detected by RT-PCR (82.6%), IFA (10.1%), and both RT-PCR and IFA (7.3%). Most patients (87.0%) were aged ≥ 50 years. Cardiovascular diseases, pulmonary diseases, immunocompromised hosts, and diabetes were the major comorbidities. The common manifestations were cough (92.8%), dyspnea (91.3%), sputum production (87.0%), tachypnea (75.4%), wheezing (73.9%), and fever (71.0%). Fifty- five patients (79.7%) were diagnosed with pneumonia. Hypoxemia (SpO2 ≤ 92%) was found in 53.6% patients. Twenty-five of 69(36.2%) patients developed respiratory failure and required ventilatory support. Cardiovascular complications were found in 24.6% of patients. Congestive heart failure, acute myocardial infarction (MI), new atrial fibrillation, and supraventricular tachycardia were found in 9(13.0%), 7(10.1%), 4(5.8%), and 3(4.3%) of 69 patients, respectively. Overall mortality was 15.9%. Pneumonia (81.8%) and acute MI (18.2%) were the major causes of death. CONCLUSIONS: Most adult hospitalized patients with RSV infection were of advanced age and had comorbidities. Cardiopulmonary complications were the major causes of death. Management and prevention of RSV infection in these vulnerable groups are necessary.

Unexpected pulmonary involvement in extrapulmonary tuberculosis patients.

BACKGROUND: This study aimed to assess the utility of sputum examinations and chest radiographs (CXRs) in patients with extrapulmonary tuberculosis (XPTB) to detect pulmonary involvement of tuberculosis (TB). METHODS: We studied 72 XPTB patients who were managed through the TB Program, King County, WA, from January 2003 through November 2004. RESULTS: The two most common sites of XPTB were the lymph nodes (36 [50%]) and pleura (12 [17%]). Thirty-five of 72 XPTB patients (49%) had abnormal CXR findings. Sputum was not obtained from 15 patients despite sputum induction. Of the 57 patients from whom sputum was collected, 30 (53%) had abnormal CXR findings, 5 (9%) had sputum smears that were positive for acid-fast bacilli, and 12 (21%) had sputum cultures that were positive for Mycobacterium tuberculosis. Weight loss was significantly associated with positive sputum culture findings in a multivariate analysis (odds ratio, 4.3; 95% confidence interval, 1.01 to 18.72; p = 0.049). There was no significant difference in the occurrence of positive sputum culture results between patients with abnormal CXR findings and those with normal CXR findings (7 of 30 patients [23%] vs 5 of 27 patients [19%], respectively; p = 0.656). Of 24 HIV-negative XPTB patients with normal CXR findings, 2 patients (8%) had positive sputum culture findings. CONCLUSIONS: CXR results did not reliably differentiate XPTB patients with and without positive sputum culture findings. Some XPTB patients had positive sputum culture results despite normal CXR findings and negative HIV status. Weight loss in XPTB patients was associated with positive sputum culture results. Sputum examinations in XPTB patients, regardless of the CXR results, may identify potentially infectious cases of TB.

Chest radiographic evolution in fat embolism syndrome.

OBJECTIVE: To characterize the temporal chest radiographic findings of fat embolism syndrome. MATERIAL AND METHOD: Twenty-nine patients with clinically diagnosed fat embolism syndrome between 1988-1999 were retrospectively identified from the Trauma Registry of Haborview Medical Center, University of Washington. In twenty-two patients, complete medical records and serial chest radiographs were available. All images were reviewed by a dedicated thoracic radiologist. RESULTS: Two of 22 patients had normal radiographs throughout hospitalization, while 20/22 developed abnormal chest radiographs. The radiographic findings were consistent with non-specific diffuse pulmonary edema in all abnormal cases. The time to appearance of evident radiographic lung injury was < 24 hours of initial trauma in 10/20 (50%), between 24-48 hours in 4/20 (20%), between 48-72 hours in 5/20 (25%), and 1 patient (1/20, 5%) developed an abnormal chest radiograph after 72 hours. Ten of 20 patients (50%) with abnormal radiographs had complete resolution of the edema pattern within 1 week of development of opacities, 3/20 (15%) cases showed complete radiographic resolution between 1-2 weeks, 2/20 (10%) cases showed complete radiographic resolution between 2-3 weeks, 1/20 (5%) showed complete radiographic resolution between 3-4 weeks, and 4/20 (20%) died without resolution of the radiographic finding. CONCLUSION: The chest radiographic appearance of fat embolism syndrome is non-specific. Normal radiographs can also be seen. Most patients presenting with a normal initial radiograph develop radiographic evident abnormalities within 72 hours of injury and most cases showed radiographic resolution within 2 weeks of hospitalization. Although chest imaging play a little role in the clinical management of fat embolism syndrome, understanding of temporal presentation and evolution of the otherwise non-specific pulmonary opacities may help to avoid unnecessary evaluation in selected patients.

Extensive pulmonary alveolar microlithiasis.

Pulmonary alveolar microlithiasis is a rare pulmonary disorder that is caused by abnormal sodium-dependent phosphate co-transporter from the mutation of SLC34A2 gene, leading to accumulation of microliths in the alveoli. We report the extensive pulmonary alveolar microlithiasis in an elderly woman who presented with progressive dyspnea for 2 months. Chest radiograph revealed diffuse pulmonary calcification. Tissue histopathology from open lung biopsy demonstrated widespread intra-alveolar laminated calcium deposits compatible with pulmonary alveolar microlithiasis.

Benign metastasizing leiomyoma.

Pulmonary metastases from benign-appearing smooth muscle tumors of the uterus are rare, and are termed benign metastasizing leiomyoma (BML). Affected patients usually present with single or multiple lung nodules and are usually women who have undergone hysterectomy. Only a few cases of BML with lung cysts have been reported, with 2 patients presenting with spontaneous pneumothoraces. We report a case of BML in a 29-year-old woman with an abnormal preoperative chest radiograph who several years after hysterectomy developed spontaneous bilateral pneumothoraces.