This report is based on observations during the conduct of a larger study to develop diagnostic

criteria for childhood tuberculosis (TB). Of 20l children confirmed to have pulmonary or lymph

node TB, 84 had normal chest radiographs. Computerized tomography (CT) of the chest was

performed in nine of them, seven of whom had normal chest radiographs while two had visible

calcification. Eight of the nine children had definitive lesions detected by computerized

tomography of the chest. While five children had primarily hilar lymph node enlargement, three

had pulmonary parenchymal lesions. The use of more sensitive diagnostic tests like computed

tomography helps to detect tuberculosis lesions not otherwise visualized on chest radiographs.

This report highlights the difficulty in excluding active tuberculosis in children. More studies are

required on the role of CT scans in the diagnosis of tuberculosis in children

Datta, Manjula

Paramasivan, C N

Raghavan, Aarti

Saravanan, K C

Swaminathan, Soumya

NIRT Institutional Repository

BRIEF REPORTSINDIAN  PEDIATRICS 258 VOLUME 42__MARCH 17, 2005unique extract for functionally enhancedpersonal care products (skin and hair).Agro Food Industry Tech 1994; July/August;pp. 19-21.5. Needlman RD. Assessment of growth anddevelopment, In: Nelson WE, Vaughan VC III,Behrman RE, Kliegman RM, editors. NelsonTextbook of Pediatrics. 14th ed.Philadelphia: WB Saunders Co. 1992. pp.40-43.6. Plummer DT. In: An Introduction to PracticalBiochemistry, 2nd edition. New Delhi: TataMcGraw Hill Publication. 1978. p 207-209.7. Miwa H, Yamamoto M, Nishida T, Nunoi K,Kikuchi M. High-performance liquid chromato-graphic analysis of serum long chain fatty acidby direct derivatisation method. J Chromatogr1987; 416: 237-245.8. Rutter N. Hull D. Reduction of skin water lossin the newborn. Effect of applying topicalagents. Arch Dis Child 1981; 56: 669-672.Computerized Tomography Detects Pulmonary Lesions in Children withNormal Radiographs Diagnosed to have TuberculosisSoumya Swaminathan, Aarti Raghavan, Manjula Datta*, C.N. Paramasivanand K.C. Saravanan†From the Tuberculosis Research Center (Indian Council of Medical Research), Chennai,*The Tamil Nadu Dr. M.G.R. Medical University, Chennai and †Government Stanley MedicalCollege and Hospital, Department of Radiology, Chennai, India.Correspondence to: Dr. Soumya Swaminathan, Division of HIV/AIDS, Tuberculosis ResearchCenter, Mayor V. R. Ramanathan Road, Chetpet, Chennai 600 031, India.E-mail: doctorsoumya@yahoo.comManuscript received: May 11, 2004, Initial review completed: August 4, 2004;Revision accepted: September 21, 2004.This report is based on observations during the conduct of a larger study to develop diagnosticcriteria for childhood tuberculosis (TB). Of 20l children confirmed to have pulmonary or lymphnode TB, 84 had normal chest radiographs. Computerized tomography (CT) of the chest wasperformed in nine of them, seven of whom had normal chest radiographs while two had visiblecalcification. Eight of the nine children had definitive lesions detected by computerizedtomography of the chest. While five children had primarily hilar lymph node enlargement, threehad pulmonary parenchymal lesions. The use of more sensitive diagnostic tests like computedtomography helps to detect tuberculosis lesions not otherwise visualized on chest radiographs.This report highlights the difficulty in excluding active tuberculosis in children. More studies arerequired on the role of CT scans in the diagnosis of tuberculosis in children.Key words: Computerized tomography, Tuberculosis.TUBERCULOSIS (TB) in the pediatricpopulation produces short-term morbi-dityand mortality and also serves as a reservoir foradult forms of the disease. The natural historyof tuberculosis in any age group comprises ofexposure, infection and disease. In children, thedifferentiation between infection and disease isnot as clear-cut as in adults. The situation iscompounded by the absence of signs andsymptoms as well as the lack of specificBRIEF REPORTSINDIAN  PEDIATRICS 259 VOLUME 42__MARCH 17, 2005radiographic features at the stage of primaryinfection. The tuberculin reaction is the onlyknown method of detecting TB infection but isknown to be falsely negative in a variety ofsituations including malnutrition and in thepresence of severe viral infections. Radio-graphic changes are often found later in thedisease spectrum and are influenced by the hostinflammatory reaction. Detection of acid-fastbacilli is rare and mycobacterial cultures taketime(1). There is thus a need for betterdiagnostic methods to detect tuberculosisinfection and disease in children. This reportdescribes the computerized tomography (CTscan) findings in nine children who showedstrongly reactive tuberculin reactions, hadMycobacterium tuberculosis in gastric lavagecultures but had chest radiographs that werenormal. They were observed during the courseof a larger study on diagnostic strategies forchildhood tuberculosis in Chennai, SouthIndia.Subjects and MethodsChildren between the ages of six monthsand twelve years attending the outpatientdepartment of the following hospitals wereincluded in this study: (a) Institute of SocialPediatrics, Government Stanley MedicalCollege, Chennai; (b) Department ofPediatrics, Sri Ramchandra Medical Collegeand Research Institute, Porur, Chennai and (c)the Kanchi Kamakoti Child’s Trust Hospital,Chennai.Children presenting with cough or fever formore than two weeks, more than six episodes ofrespiratory infection in three months, failure tothrive or unexplained loss of weight werereferred for the study. A strong clinicalsuspicion in the absence of these symptoms wasalso considered as sufficient grounds forinvestigation. Detailed history including allsymptoms and a history of contact with TB wasrecorded. Clinical examination was conductedand findings recorded.Chest radiographs and tuberculin tests wereperformed. The pediatrician and radio-logistreviewed radiographs independently–bothwere blinded as to the clinical status of thepatient. In case of disagreement between thetwo, a third opinion was obtained from anotherpediatrician. Tuberculin test was done using1TU PPD RT 23 with Tween 80 and indurationwas recorded after 48 to 72 hours. Thediagnosis of tuberculosis was based on sputumor gastric lavage smear/culture (on twoconsecutive days early in the morning) orlymph node biopsies with histopathologicalexamination and culture obtained from thosewho had significantly enlarged superficialnodes. CT scans could be performed only innine children due to lack of availability. Allscans were performed at the GovernmentStanley Medical College and Hospital,Chennai, after culture results had becomeavailable. All children with TB diagnosed weretreated with a full course of anti tuberculoustherapy. The study was approved by theInstitute’s Ethics committee and informedconsent was obtained from the parents.Results2352 children were referred for the study;tuberculosis was confirmed in 201 eitherbacteriologically or histopathologically. Thechest radiographs of 84 of these children wereread as normal by the pediatrician andradiologist. We were able to perform CT scansin nine of these children and details of theirinvestigations are shown in Table I. Whileseven of them had normal chest radiographs(confirmed by reading the films again), two hadevidence of calcification. All were HIV-negative. Eight had Mycobacterium tuber-culosis isolated from gastric lavage cultureswhile one child had a lymph node biopsyBRIEF REPORTSINDIAN  PEDIATRICS 260 VOLUME 42__MARCH 17, 2005suggestive of tuberculosis. The CT scan wasabnormal in eight of the nine patients. Whilefive children had primarily hilar lymph nodeenlargement, the other three had pulmonaryparenchymal lesions.DiscussionThe role of CT scans in pediatric TB hasbeen explored in a few studies; none are fromresource-restricted settings. Delacourt, et al.(2)performed CT scans in 15 children withpositive tuberculin reactions and foundevidence of enlarged intra-thoracic nodes in60%. They suggest that CT scans could play arole in the early detection of tuberculosis whereactive disease has not been diagnosed due toabsence of clinical findings and normal chest X-rays. Similarly Gomez Pastrana, et al.(3)detected intrathoracic lymphadenopathy in 14of 22 (63%) children with tuberculous infectionwithout disease. Kim, et al.(4) while desrib-ing the CT findings of pulmonary tuberculosisin children noted that in 20% of patients thediagnosis was suggested only on CT scans; thecharacteristic CT finding was mediastinal orhilar lymphadenopathy with rim enhance-mentor calcification. Neu, et al. (5) also describedsix children in whom CT scans revealed hilar/mediastinal adenopathy with equivocal ornegative chest radiographs.During the course of our study we observedthat a fair proportion of children with gastriclavage culture positive for Mycobacterimtuberculosis had normal chest radiographs. CTscans done on a subset of these children pickedup lesions in the majority. Only two of the ninechildren reported here had any abnormalitydetected on plain radiograph and both theseTABLE I–Findings in Nine Children with TB Disease and Normal Radiographs.Age Sex Tuberculin Bacteriology Chest CT scan(yrs) reaction (mm) X-ray5 M 24 Culture+ N Right paratracheal gland with calcification.11 F 15 Lymph node biopsy + N Righ tracheobronchial nodes with anteriormediastinal mass.3 F 15 Culture+ N Normal3 F 17 Culture + N Calcification in left hilar gland3 F 14 Culture Calcific Right retrocardiac patchy pneumoniadensity including calcific densityright lowerzone11 M 15 Culture + N Right hilar node enlargement5 M 15 Culture + N Right mediolateral calcific node with roundedopacity. Left lower lobe with varying density(consolidation leading to liquification)8 F 0 Culture + N Right basal lateral segment nodular opacity atthe level of diaphragm6 M 15 Culture + Calcifica- Bilaterial hilar adenitis producing obstructivetion in emphysemahilar areaBRIEF REPORTSINDIAN  PEDIATRICS 261 VOLUME 42__MARCH 17, 2005were calcifications. Pulmonary CT scansshowed lymph node enlargement in five,consolida-tion in four (with liquefaction in one)and an anterior mediastinal mass in one patient.While there was no classical or universalfeature diagnostic of tuberculosis, the CT scanwas able to pick up significant abnormalitiesnot detected by plain radiographs.Our findings raise two important issues.Firstly, the role of CT scans in the diagnosis ofpediatric TB. Though it is a more sensitive testthan plain radiograph of the chest, it cannot beroutinely recommended due to the cost andinaccessibility in developing countries wheretuberculosis is most common. However, it canbe used as an adjunct in high-risk groups wherecurrent modalities are inconclusive and clinicalsuspicion is high.The other issue is regarding treatment. Asmore sensitive tests are developed, it isbecoming easier to detect evidence ofmycobacterial infection, where in the past itwas not possible. It is clear that there is acontinuum between tuberculous infection anddisease, particularly in early childhood. Six ofthe nine children in this study were under theage of six years. The demonstration ofunrecognized active disease in many infectedchildren raises the question of adequatetreatment for these children. Since it isimpossible in many cases to differentiateclearly between infection and disease with thecurrent diagnostic modalities, it may beadvisable to treat infection also (preventivetherapy) with two drugs. A two-drug regimenisoniazid and rifampicin) has been shown to beeffective in treating uncomplicated pulmonarytuberculosis and can effectively be used forchemoprophylaxis also(6).Contributors: SS and MD were responsible for studydesign, monitoring and supervision. SS and AR wereresponsible for data analysis and report writing. CNPwas involved in laboratory aspects and KCS helpedwith interpretation of radiographs and scans.Funding: None.Competing Interests: None.REFERENCES1. Khan EA, Starke JR. Diagnosis of tuberculosisin children: Increased need for better methods.Emerg Infec Dis 1995; 1: 115-123.2. Delacourt C, Mani TM, Bonnerot V, Blic J,Sayeg N, Lallemand D, et al. Computedtomography with normal chest radiograph intuberculous infection. Arch Dis Child 1993; 69:430-432.3. Gomez-Pastrana D, Caro Mateo P, TorronterasSantiago R. Computed tomography andpolymerase chain reaction in tuberculosisinfection in children. Arch Bronchoneumol1996; 32:  500-504.4. Kim W S, Moon W K, Kim I O, Lee H J, Im J G,Yeon K M, et al. Pulmonary   tuberculosis inchildren: evaluation with CT. Am JRoentgenol1997; 168: 1005-1009.5. Neu N, Saiman L, San Gabriel P, Whittier S,Knirsch C, Ruzal Shapiro C, et al. Diagnosis ofpediatric tuberculosis in the modern era. PediatrInfect Dis Journal 1999; 18: 122-126.6. Ramachandran P, Kripasankar AS, Durai-pandian M. Short course chemotherapy forpulmonary tuberculosis in children. Ind J Tub1998; 45: 83-87.Key Messages• Children with active tuberculosis may have normal chest radiographs.• CT Scan is a sensitive diagnostic test to detect pulmonary lesions.

Computerized Tomography Detects Pulmonary Lesions in Children with

Normal Radiographs Diagnosed to have Tuberculosis

http://eprints.nirt.res.in/729/1/200551.pdf

Computerized Tomography Detects Pulmonary Lesions in Children with Normal Radiographs Diagnosed to have Tuberculosis

Abstract

Similar works

Full text

Available Versions

NIRT Institutional Repository