| Abstract|| |
Aim: Benefit of thorax computed tomography was investigated when lung graphy remains insufficient in the diagnosis of tuberculosis. Materials and Methods: 55 patients across children with tuberculin skin test (TST) positive nonspecific symptom who applied to the tuberculosis polyclinic of our hospital were investigated between ages of 0-18, determined positivity in their TST test or with tuberculosis contact story. Age, gender, complaining, TST results, existence/number of BCG scar, underlying disease, contact status, cigarette exposure, laboratory findings, Lung graphy and thorax CT findings of patients were compared. Results: Average age of cases was 110, 38±42, 8 months. Lung graphy results of 36.4% of cases were abnormal while 63.6% were normal. Results of 30.9% (n=17) were abnormal while 69.1% (n=38) of cases were normal. No compliance is observed between results of CT and Lung graphy (p<0.05). Lung graphy was found to have a low positive true diagnosis value, a higher negative true diagnosis value. A significant difference is observed between tuberculosis sighting case and scar numbers of BCG (p<0.05). Conclusion: Taking lung graphy and thorax CT is beneficial and significant in the investigation of tuberculosis disease in patients with positivity of tuberculin skin test. Computed tomography is more sensitive method in comparison to lung graphy in terms of all findings.
Keywords: Computed tomography, lung graphy, tuberculosis, tuberculin skin test
|How to cite this article:|
Efe E, Arica V, Dogan M, Arica SG. Comparison of Lung graphy and thorax computed tomography findings in children with Tuberculin skin test positive. Ann Trop Med Public Health 2012;5:502-7
|How to cite this URL:|
Efe E, Arica V, Dogan M, Arica SG. Comparison of Lung graphy and thorax computed tomography findings in children with Tuberculin skin test positive. Ann Trop Med Public Health [serial online] 2012 [cited 2020 Jul 3];5:502-7. Available from: http://www.atmph.org/text.asp?2012/5/5/502/105144
| Introduction|| |
Although tuberculosis is a known very old disease, still continues to be an important health issue in both developed and developing countries because of its morbidity, mortality and economical effects.  One-third of the world's population are infected with tuberculosis bacillus. Every year one percent of the world's population are infected with tuberculosis bacillus.  It is obvious that tuberculosis issue will continue for many years since constantly new patients will come out of the infected population. The incidence of tuberculosis (tuberculosis) disease in our country is 25.2 per hundred thousand when calculated according to the patients registered to Tuberculosis Control Dispensaries in 2007.  Active tuberculosis was developed in 8.8 millions of people all around the world in 2005 and 1.6 millions of them died because of the disease. 
Pathophysiology of tuberculosis is complicated. Existence of a delay between the infection and the disease also makes events more uncertain.  Nowadays, it is diagnosed with tuberculin skin test (TST) indicating a hypersensitivity reaction delayed against to the purified protein derivative (PPD) of M. tuberculosis in a person non-immunized to the infection. TST does not provide information about the disease, only indicates whether the person is infected or not.  Individuals suspected to have tuberculosis, individuals in close contact are investigated with TST, lung graphy, physical examination and thorax computed tomography (CT). Although Lung graphy is a very good method to identify pulmonary tuberculosis, minimal exudative tuberculosis might be overlooked in lung graphy or the graphy might be normal. , Previously it was not described that Thorax CT is superior to conventional radiographies in the activity determination of Thorax CT and thorax CT findings of pulmonary tuberculosis.  In recent years it was found that high resolution computed tomography (HRCT) is superior to smooth lung graphy and standard Thorax CT in localization of the disease in pulmonary lobule and evaluating the pulmonary parenchymal disease. ,
| Materials and Methods|| |
55 patients between ages of 0-18, TST positive, with nonspecific symptom or chronic symptom, receiving immunosuppressive therapy and diagnosed with TST positivity for research purposes or with tuberculosis contact story who applied to the Children Infection Diseases Tuberculosis Polyclinic of Istanbul Bakirkoy Pediatric Hospital were studied. Age, gender, complaining, tuberculin skin test (TST) results, existence/number of BCG scar, underlying disease, contact status, cigarette exposure, laboratory findings, Lung graphy and thorax CT findings of patients were compared. 15 mm and larger of induration diameters in patients with BCG scar and 10mm and larger in patients without BCG scar regarded as positive on basis of the reference book for controlling tuberculosis in Turkey published by Turkish Ministry of Health, Directorate of Tuberculosis Control Department. The upper limit of normal erythrocyte sedimentation rate was considered as 20 mm/h.
NCSS (Number Cruncher Statistical System) 2007andPASS 2008 Statistical Software (Utah, USA) program was used for statistical analyses while evaluating the findings obtained in the study. Besides descriptive statistical methods (Average, Standard Deviation), Student t test was used while evaluating the study data in comparison of quantitative data and in comparisons of parameters exhibiting normal distribution between two groups. Chi-Square test, Fisher's Exact Chi-Square test and Mc Nemar test were used in comparison of qualitative data. Diagnostic screening tests were utilized in calculations of sensitivity, specificity. Significance was evaluated at the level of p<0.05.
| Findings|| |
56.4% (n=31) of cases were female, 43.6% (n=24) were male. Average age of patients was 110.38±42.8 months (minimum 22 months-maximum 195 months). Average of TST levels was 18.69±3,8 (minimum 13-maximum 30). 12.7% (n=7) of cases were slim, 76.4% (n=42) were normal and 10.9% (n=6) were obese. There was no tuberculosis story in the family of 69.1% (n=38) of cases while in the family of 30.9% (n=17) there is a previous tuberculosis story. There was no TST positivity in brother/sister of 87.3% (n=48) of cases while there is a TST positivity in 12.7% (n=7). Cigarette was not used in the houses of 47.3% (n=26) of cases while it is used in the houses of 52.7% (n=29).
There were cough in 58,2% (n=32), pituitary in 21.8% (n=12), dyspnea in 20% (n=11), chest pain in 10.8% (n=6), sweating in 25.5% (n=14), fever in 16.4% (n=9), asthenia in 20% (n=11) and weight loss in 12.7% (n=7) of cases. One BCG scar in 78.2% (n=43) of cases and two BCG scars in 14.5% (n=8) were determined while no BCG scar was observed in 7.3%(n=4).
There was no contact in 69,1% (n=38) of cases while 30.9% (n=17) had contact with the patient with tuberculosis. No immunosuppressive disease was observed in 98,2% (n=54) of cases while it was observed in 1.8% (n=1). Leukocytosis is not observed in 94.5% (n=52) of cases while it is observed in 5.5% (n=3). Anemia is not observed in 98.2% (n=54) of cases while it is observed in 1.8% (n=1). High sedimentation is not observed in 89.1% (n=49) of cases while it is observed in 10.98% (n=6). There is no underlying disease in 87.3% (n=48) of cases while there is in 12.7% (n=7). Tuberculosis was diagnosed in 20% (n=11) of cases and antituberculosis therapy was applied, tuberculosis disease was excluded in 80% (n=44) of cases and prophylaxis therapy was applied.
Lung graphy results were abnormal in 36.4% (n=20) of cases while they were normal in 63.6% (n=35). When distribution of 20 non-normal cases was investigated; findings of LAP in 60% (n=12), consolidation in 35% (n=7), cavity in 5% (n=1) and prominence in peribronchial traces in 10% (n=2) were encountered.
CT results of 30.9% (n=17) of cases were abnormal while CT results of 69.1% (n=38) of cases were normal. When distribution of 17 non-normal cases was investigated; lymphadenopathy in 41.1% (n=7), parenchymal consolidation in 29.4% (n=5), atelectasia in 23.5% (n=4), icy glass appearance in 17.6% (n=3), linear density in 23.5% (n=4), prominence in bronchovascular traces in 11.8% (n=2), bronchiectasis in 5.9% (n=1), acinar infiltration in 5.9% (n=1), bullous formation in 5.9% (n=1), prominence in major fissure in 5.9% (n=1), nodular density in 5.9% (n=1), fibrotic band in 5.9% (n=1), air capture areas in 5.9% (n=1) were encountered [Table 1].
Given all patients, no significant difference is observed between two measurement methods when the Lung graphy investigation was performed according to CT results (p>0.05). Accordance is observed between CT and Lung graphy results; we determined the non-random Kappa accordance level as 28.1%. Lung graphy was determined as an abnormal finding in 10 of 17 cases having abnormal findings in CT; sensitivity was determined as 58.8%, specificity as 71.0%, positive estimation value as 47.6%, negative estimation value as 79.4% [Table 2].
All lymphadenopathies (LAM) were in the right lung in CT. LAM was determined in seven patients in CT, 12 patients in Lung graphy. Calcification existence in three patients in CT determined in lymphadenopathy could not be determined with Lung graphy. Six of LAMs in CT were determined in the right hilus. Two right subcarinal LAM, Two right paratrachial LAM and LAM in the right upper lobe were not observed with Lung graphy. LAM was observed with Lung graphy in six patients (wrongly positive). Given all patients, accordance is observed in the determination of lymphadenopathy between CT and Lung graphy results; the non-random Kappa accordance level was 56.1%. Lung graphy was determined as an abnormal finding in six of seven cases having lymph node findings in CT; sensitivity was determined as 85.7%, specificity as 87.5%, positive estimation value as 50%, negative estimation value as 97.7%.
Consolidation was determined in five patients in CT (all of them received the diagnosis of tuberculosis). Consolidation was determined in two (consolidation and cavity in one of them, consolidation in different localisation in the other one) of the same patients with Lung graphy. Consolidation was not observed with CT in five of seven patients determined consolidation in Lung graphy. Given all patients, no significant difference is observed between two measurement methods when the Lung graphy investigation is performed according to CT results for consolidation (p>0.05). Accordance is observed between CT and Lung graphy results; the non-random Kappa accordance level was determined as 25.4%. Lung graphy was determined as an abnormal finding in two of five cases having infiltration findings in CT; sensitivity was determined as 40%, specificity as 90%, positive estimation value as 28.6%, negative estimation value as 93.6%.
Statistically significant relationship is observed between tuberculosis and Lung graphy results (p<0.01). Tuberculosis sighting rate is significantly high in lung graphy abnormal cases, absence rate is significantly high in normal cases. Statistically significant relationship is not observed between tuberculosis and Lung graphy consolidation results (p<0.05). Statistically significant relationship is observed between tuberculosis and CT results (p<0.01). Tuberculosis sighting rate is significantly high in CT abnormal cases, absence rate is significantly high in normal cases. Statistically significant relationship is observed between tuberculosis and lymphadenopathy results in CT (p<0.01). Tuberculosis is observed in all cases with lymphadenopathy in CT, absence rate is significantly high in normal cases. Statistically significant relationship is observed between tuberculosis and consolidation results in CT (p<0.01). Absence rate is significantly high in normal cases while tuberculosis is observed in all cases with consolidation in CT [Table 3].
No statistically significant accordance is observed between CT and Lung graphy in total of 55 patients when consolidation and LAM are investigated together (p<0.05). 10 of 46 cases found as normal in CT in terms of consolidation and LAM in 55 patients were determined as pathologic in Lung graphy.
Given all patients, in parenchymal abnormality evaluation; accordance is not observed between CT and Lung graphy results (p<0.05); the non-random Kappa accordance level is 17.3%. Lung graphy was determined as an abnormal finding in 4 of 16 cases having parenchymal abnormality findings in CT; sensitivity is 25%, specificity 89.7%, positive estimation value 50%, negative estimation value 74.5%.
No significant difference is observed according to tuberculosis sighting status between age averages and averages of TST levels (p>0.05). No significant difference is observed according to tuberculosis sighting status between gender distributions and BMI levels either (p>0.05). Again no significant difference is observed according to tuberculosis sighting status between TST positivity in brother/sister, previous disease in the family and cigarette use rates at home (p>0.05) [Table 4].
|Table 4: Evaluation of specifications according to presence of tuberculosis|
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Significant difference is observed between tuberculosis sighting status and BCG scar numbers (p<0.05); One and two scar sighting ratio is high in cases observed no tuberculosis while scar no-sighting rate is high in cases observed tuberculosis.
| Discussion|| |
Nonspecific complaining such as fever, in acceptance, cough, pituitary, weight loss, asthenia, sweating can be observed in the course of tuberculosis disease.  In this study, the most frequently encountered complaints were determined as cough, pituitary and sweating. These nonspecific symptoms may be evaluated like a simple viral-bacterial infection when monitoring methods are not used. This leads to an extension in diagnosis time.
BCG vaccine does not prevent the settlement of tuberculosis into the lung tissue but can decrease the frequency of pulmonary and extra pulmonary tuberculosis.  Statistically significant difference is observed in our study between tuberculosis sighting status and BCG scar numbers. One and two scar sighting ratio was determined as high in cases observed no tuberculosis while scar no-sighting rate is high in cases observed tuberculosis. This also shows the effectiveness of vaccination in the age of childhood age in our country.
Lung graphy plays a major role in screening, diagnosis and response to the therapy of the patient with tuberculosis. However, radiograms may be normal in patients with active disease or may only show mild or non-specific findings.  Frequent reasons in skipping the diagnosis of tuberculosis are inadequacy in identification of hilar and mediastinal lymphadenopathy that are manifestation of the primary disease, confuse of mild level parenchymal abnormalities in reactivation patients and inadequacy in identification of the mass surrounded by upper lobe nodule or little nodular opacities, or scarification that may indicate tuberculosis.  CT is more sensitive than Lung graphy in distinction of parenchymal disease or lymphadenopathy both in difficult localization and spread. ,,,
The most frequently observed CT finding in children with tuberculosis is the lymph node enlargement observed in 90-95% of them. , Enlarged lymph nodes in CT show contrasting with hypodense and peripheric hyperdense middle indicating caseous necrosis. , Lymph nodes in the right paratrachial and tracheobronchial area recognized easily when they reach the adequate size but defining small changes is difficult. Only 23% of lymph nodes in subcarinal area can be determined whereas they can be determined in 89% of the patients with lymph node bigger than 15mm in paratrachial or tracheobronchial area in lung graphy with thorax CT. 
Kim et al could not determine adenopathy in 21% of patients with chest radiography, CT was observed to be more beneficial in diagnosis of tuberculosis infection in patients with normal or suspected Lung graphy. 
Delacourt et al determined lymph node enlargement in children with tuberculosis but normal lung graphy as 60%. Based on this finding, they suggested taking thorax CT in children with primary tuberculosis having TST positive, physical examination and normal Lung graphy and performing tuberculosis prophylaxis if lenfoadenopathy is determined. 
In a study conducted in our country; Although Ozbek et al have determined lymphadenopathy in a ratio of 61% in lung graphy in 28 children patients monitored with tuberculosis meningitis, it was determined in a ratio of 82% with thorax CT. In addition, lymphadenopathy was determined in 13 patients with thorax CT that is specific to granulomatous disease, with an irregular middle, hypodense and its peripheries show hyperdense contrasting. 
In another study conducted in our country Uzum et al have determined pathologic findings in thorax CT in 81,2% of patients in the study that they performed in 48 symptomatic children with active pulmonary tuberculosis in their family members. As a result of the study it was concluded that TST and lung graphy are not adequate in children exposed to tuberculosis and suspected cases with an unknown family story; to diagnose tuberculosis and prevent the disease.  Also in our study, positive true diagnosis value of lung graphy is low, negative true diagnosis value is higher. Therefore, we have reach the conclusion that re-evaluation with CT is necessary in patients especially with pathologic lung graphy in order to prevent diagnosing the patient with tuberculosis mistakenly and obliging to take medication for a long time.
In a study performed by Yaramýþ et al in 74 children with tuberculosis meningitis, lung graphies and thorax CTs were compared. Lung graphy findings were determined as abnormal in 32 cases (43%) (hilar adenopathy 32%, miliary pattern 18%, bronchopneumonic pattern 24%), thorax CT findings as abnormal in 65 cases (88%). Mediastinal and hilar lymphadenopathy were found in 46%, miliary pattern in 23%, bronchopneumonic in filtration in 23%. It was determined that thorax CT is beneficial in evaluating children with tuberculosis meningitis if Lung graphy is normal or uncertain. 
Radiologic diagnosis of tuberculosis can be made in only 49% of all cases correctly at the beginning.  Diagnosis of lung tuberculosis with CT is accurate in 91% of patients and tuberculosis is excluded accurately in 76% of patients.  HRCT is particularly helpful in determination of small cavitation focuses in areas interfering with pneumonia and dense nodularity and scarification.  In a study performed in 41 patients with active tuberculosis, whereas lung radiographies showed cavities only in a ratio of 22%, HRCT showed them in a ratio of 58%.  In addition, HRCT for the diagnosis of tuberculosis is also beneficial to show activity of the disease. Experimental diagnosis of active tuberculosis with CT can be made according to the existence of cavitation exhibiting a spread to parenchymal abnormality pattern and endobronchial spread like centrilobular nodules or budding trees. In the series of Lee et al, 80% of patients with active disease and 89% of patients with inactive disease were separated correctly with HRCT.  CT is also helpful in the evaluation of pleural complications such as tuberculosis effusion, empyema and bronchopleural fistula and can show also pleural disease that is not obvious in lung graphy. 
In conclusion, taking lung graphy and CT is beneficial and significant in the investigation of tuberculosis disease in patients with TST positivity. Observation of consolidation in lung graphy of these patients does not mean tuberculosis disease in every case. CT is a much more sensitive method in comparison to lung graphy in terms of all findings; determination of LAP and /or consolidation in CT of patients with TST positivity depends on tuberculosis. Accordance cannot be observed between thorax CT and lung graphy results in determination of parenchymal abnormality in all patients and when consolidation and LAM are considered together (p<0.05). In lung graphy of this group of patients, their CTs can be found as normal when the pathology is monitored, thus the pathology in the graphy does not always depend on tuberculosis.
In "what kinds of patients" or "what kind of population" chest CT is useful for diagnosing tuberculosis. CT is important in decision of preventive or therapeutic anti-tuberculosis therapy of patients with TST positivity and significantly superior to lung graphy.
| Acknowledgements|| |
Thank you for their contribution to health workers and nurses.There is no conflict of interest between the authors.There is ethical committee approval for the study.
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Medical Faculty of the Mustafa Kemal University, 31100, Serinyol, Antakya, Hatay
Source of Support: None, Conflict of Interest: None
[Table 1], [Table 2], [Table 3], [Table 4]