AJR:168, April 1997 1005

PulmonaryTuberculosis inChildren: Evaluation with CT

Woo Sun Kim1Woo Kyung Moon1

In-One Kim1

Hoan Jong Lee2

Jung-Gi 1m1Kyung Mo Yeon1

Man Chung Han1

OBJECTIVE. The purpose of our study was to describe the CT findings of pulmonary

tuberculosis in children and to define indications for the use of CT.

MATERIALS AND METHODS. CT findings in 41 consecutive children with con-

firmed tuberculosis were retrospectively analyzed by two radiologists. Chest radiographs and

medical records were also reviewed to determine whether additional information provided by

CT scans had altered clinical management of the disease.

RESULTS. Mediastinal and hilar lymphadenopathy was seen in 34 patients (83%). In 29

of these patients, enlarged nodes had low-attenuation centers and enhancing rims. In the five

other patients, enlarged nodes had calcification. Segmental (n = 12) or loban (ii = 8) air space

consolidation was seen in 20 patients (49%), nodules of bronchogenic spread were seen in 12

patients (29%), and miliary nodules were seen in seven patients (17%). Bronchial (ii = 15),

pleural (n = 7), pericardiac (n = 1), or chest wall (n = I ) complications of tuberculosis were

seen in 22 patients (54%). In eight (20%) of 41 patients, a diagnosis of tuberculosis was sug-

gested only on CT scans, which revealed low-attenuation nodes with rim enhancement, calci-

fications, and nodules of bronchogenic spread or miliary nodules. These findings were not

seen on chest radiographs. In 15 patients (37%), CT scans provided information that altered

clinical management. Also, two of these patients underwent surgery because of pleural and

chest wall complications that were seen only on CT scans.

CONCLUSION. Mediastinal or hilar lymphadenopathy revealed as low-attenuation

nodes with rim enhancement or calcification was the most characteristic CT finding of pul-

monary tuberculosis in children. CT can be useful when tuberculosis or its complications are

suspected in children and the radiographic findings are normal on inconclusive.

Received May 20, 1996; accepted after revision

October 2, 1996.

1 Department of Radiology, Seoul National University

College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul

110-744, Korea. Address correspondence to W. S. Kim.

2Department of Pediatrics, Seoul National University

College of Medicine, Seoul 110-744, Korea.

AJR 1997;168:1005-1009

0361-803X/97/1 684-1005

© American Roentgen Ray Society

T ubenculosis remains an important

cause of morbidity and mortality

worldwide. Fueled by the worsen-

ing HIV epidemic, homelessness, drug abuse,

and immigration, the incidence of tuberculosis

in Western countries has increased dnamati-

cally. Children represent one of the high-risk

groups in the resurgence of this disease [ 1-3].

Because bacteriologic confirmation is difficult

to obtain in children, a plain radiograph along

with contact screening and the tuberculin skin

test are integral ingredients in the early diagno-

sis of tuberculosis in children.

Most tuberculosis cases in children are

related to primary infection and mediastinal or

hilar lymphadenopathy, with a focal paren-

chymal lesion being the most common radio-

graphic finding [4-7]. This combination is

helpful diagnostically when it occurs; how-

even, some children do not have these find-

ings. Lymphadenopathy without pulmonary

infiltration can be seen in infants and children

with AIDS. Chest CT findings and their role

in managing patients with pulmonary tubencu-

losis have been described mainly in adults

with postprimary tuberculosis [8-1 1].

We retrospectively reviewed the chest CT

scans, chest radiographs, and medical records

in a series of patients with primary tuberculosis

to describe the CT findings of pulmonary

tuberculosis in children and to define the use of

CT in children with pulmonary tuberculosis.

lymphadenopathy

(83%). The right

Kim etal.

1006 AJR:168, April 1997

Materials and Methods

During a 6-year period (1989-1994). 41 consec-

utive patients with bacteriologically or clinicallyconfirmed tuberculosis were studied with CT scans

and chest radiographs. The study group included 29

boys and 12 girls who were 3 months to 14 years

old (mean age. 6 years old). Eight patients (20%)

were less than 2 years old. 13 patients (32%) were

between 2 and 5 years old, 13 (32%) patients were

between 5 and 10 years old. and seven (17%)

patients were between 10 and I 5 years old. No

patients with AIDS were included in the study.A CT scan was obtained 1-10 days (mean, 5

days) after chest radiography for one or more of the

following reasons: to find or to confirm lymphaden-

opathy or a parenchymal lesion when radiographs

were inconclusive, to evaluate unusual presenta-

tions such as a masslike lesion or widespread dis-

ease, to detect or evaluate a complication such as

bronchial or pleural tuberculosis. and to evaluate

the aggravation or incomplete resolution of the dis-

ease despite antituherculous therapy. In I 3 patients

(32%), a CT scan was obtained before the diagnosis

of tuberculosis. In 18 patients (44%). a CT scan was

obtained 1-54 weeks (mean. 3 weeks) after com-

mencement of antituberculous therapy.

The diagnosis was established by positive cul-ture. staining of sputum. or gastric aspirates for

acid-fast bacilli in 21 patients (51%) and by biopsy

in I I patients (27%): surgical biopsy in six. pleural

biopsy in three. and bronchoscopic biopsy in two.

Mvcobacteriuin tuberculosis was isolated in eight

patients. In the remaining nine patients (22%), two

of three criteria were met: a tuberculin skin test with

5 TV of purified protein derivative resulted in anarea of induration of 10 mm or greater, other dis-

ease causes were ruled out and the subsequent clini-

cal course was consistent with tuberculosis, or an

adult with contagious disease caused by M. tuber-

cul#{252}siswas discovered.

CT scans were obtained with a CTTT-9800 scan-

ner or a HiSpeed Advantage System (General Elec-

tric Medical Systems. Milwaukee. WI) at 1(X) mA.

120 kVp, and 1- to 2-sec scan time. In routine scan-

ning. contiguous 5- to 10-mm-thick sections after an

IV bolus injection of contrast media were taken from

the lung apex to the diaphragm. In 14 patients, a

high-resolution CT scan with 1 .5-mm-thick sections

were obtained at 5- to 10-mm intervals. 280 mA, 120

kVp. and I -sec scan time and processed with an

edge-enhancing algorithm. In all patients, the poster-

oanterior and lateral chest radiographs were available

and obtained at 55-77 kVp. High-kilovoltage filtered

images were also available for 10 patients.

CT scans and chest radiographs were analyzedseparately by two independent radiologists with

regard to lymphadenopathy and parenchymal. bron-

chial, pleural. pericardiac, and chest wall lesions.

When observers differed, they came to a mutual

agreement. The results of the CT scans and chest

radiographs were then compared side by side and

with the knowledge of the clinical diagnosis to see

the additional diagnostic contributions of CT. Med-

ical records were also reviewed to see in how many

instances and in what circumstances the additional

information provided by CT altered the clinicalmanagement of the disease.

Results

Mediastinal and hilar

was seen in 34 patients

paratracheal nodes were involved in 30

patients, followed by the right hilar nodes in

29 patients. the left hilar nodes in 14 patients,

and the subcarinal nodes in 13 patients. Multi-

ple nodal involvement was seen in 32

patients; however, two patients had only a sin-

gle nodal lesion. In three patients, lymphaden-

opathy was seen without a concomitant

parenchymal lesion. On enhanced CT scans,

enlarged nodes with low-attenuation centers

and peripheral enhancement were seen in 29

of 34 patients (85%) (Fig. I ). In five patients,

calcification was seen within the enlarged

nodes. Three of them had taken antitubercu-

bus therapy for 4-9 months. On chest radio-

graphs, the enlarged lymph nodes were

difficult to identify in seven patients, and cal-

cification of the nodes was missed in three of

five patients.

Parenchymal lesions were seen in 31

patients. and 20 patients (49%) had segmental

(ii = I 2) or lobar (ii = 8) air space consolida-

tion. Air space consolidation was most fre-

quently seen in the right lower lobes (ii � 6)

and in anterior segments of the right upper

lobes (ii = 6). The consolidation was well-

defined and homogeneous in I 4 patients; how-

ever, in five patients with lobar consolidation,

multifocal low-attenuation areas were seen

within consolidation (Fig. I ). In six patients,

calcifications were seen within consolidation.

Two of the patients had a history of antituber-

culous therapy for 6 and I 2 months. Cavitation

Fig. 1.-Pulmonary tuberculosis causing lymphadenopathy and lobar consolidation in 2-year-old boy.A, Plain radiograph shows bulging of upper mediastinum (arrow) and consolidation in right lower lobe of lung.B, CT scan obtained 3 days after A shows right paratracheal lymphadenopathy with central low attenuation and peripheral rim enhancement (arrowheads).

C, CT scan obtained during same study as B shows dense air space consolidation of right lower lobe that contains spots of calcification and multifocal low-attenuationareas (arrows).

A

Fig. 2.-Bronchogenic spread of tuberculosis in 8-year-old boy.A, Plain radiograph shows ill-defined dense opacity obscuring right cardiac border.

B, High-resolution CT scan obtained 2 days afterA shows atelectasis of right middle lobe (Ml, variably sized cen-trilobular nodules (arrowheads), and linear branching structures (arrows) in right lower lobe. Right hilar adenop-athy (not shown) was also detected on CT scan.

A B

CT of Pulmonary Tuberculosis in Children

AJR:168, April 1997 1007

of pneumonic consolidation was seen in three

infants, and in one of these patients, the necro-

sis progressed to extensive bilateral bullous

lesions. Solitary masslike lesions were seen in

three patients. The images of all three patients

were low in attenuation, and two of the three

had peripheral rim enhancement. On chest

radiographs. focal air space consolidations

were difficult to identify in two patients, and

calcification of the parenchymal lesion was

missed in four of six patients.

Foci of nodular densities. from I mm to 2

cm, were seen in 12 patients (29%). On high-

resolution CT scans, the foci were centrilobular

in location and appeared as nodules or branch-

ing linear structures, which suggested the bron-

chogenic spread of tuberculosis (Fig. 2).

Miliary on disseminated nodules were seen in

seven patients (17%), and in four of these

patients, dense air space consolidation and

atelectasis were combined. High-resolution CT

scans showed po��nly or well-defined nodules

of 1-2 mm widely disseminated throughout the

lungs (Fig. 3). On chest radiographs. areas of

small nodules were missed in nine patients:

nodules of bronchogenic spread in eight

patients and miliary nodules in one patient.

Bronchial lesions were seen in I 5 patients

(37%). On CT scans. involved bronchi were

stenosed in seven patients and obstructed in

four patients. Bronchial wall thickening was

seen in nine patients. Endobronchial granu-

loma was seen in three patients (Fig. 4): two

lesions were calcified and one was of low

attenuation. Peribnonchial lymphadenopathy

was seen in 1 1 patients. Segmental (ii = �) or

lobar (ii = 5) atelectasis was seen in 13

patients. Obstructive emphysema associated

with hilar lymphadenopathy was seen in two

patients: in one patient the right lower lobe

was involved, and in the other patient the left

lower lobe was involved. Cylindrical bron-

chiectasis was seen in two patients and

involved the left upper lobe and the left lower

lobe in each patient. In the evaluation of bron-

chial tuberculosis, chest radiographs. even

with high-kilovoltage filtered techniques.

failed to show a bronchial stenosis in three

patients and failed to show an endobronchial

granuloma in two other patients (Fig. 4).B Pleural lesions were seen in seven patients

(17%). The lesions were free effusion associ-

ated with air space consolidation in two

patients. loculated effusion in two. pleural

thickening with calcification in two, and a cal-

Fig. 3.-Miliary tuberculosis in 13-year-old girl.A, Plain radiograph shows inconspicuous nodules in both lungs.B, High-resolution CT scan obtained 1 day afterA shows well-defined 1- to 2-mm nodules disseminated throughout lungs.

‘-... c...

Fig. 5.-Pleural and pericardiac tuberculosis in 13-year-old girl. CT scan shows bilateral pleural effusion andsubpleural parenchymal lesions (arrow) in right middle lobe. Pericardium is irregularlythickened (arrowheads).

Kim etal.

1008 AJR:168, April 1997

Fig. 4.-Bronchial tuberculosis in 11-year-oldgirl.

A, Plain radiograph shows ill-defined lesion(arrow) in left infrahilar area.B, CT scan obtained 1 day afterA shows round

calcified lesion (arrows) in left main bronchus.Note collapse of superior lingular division ofleft upper lobe.

cified mass with low-attenuation fluid in one.

CT scans showed parenchymal nodules on the

same side as pleural lesions in all patients and

showed hilar or mediastinal adenopathy in

three patients. In the evaluation of pleural

tuberculosis. chest radiographs failed to reveal

pleural lesions in two patients and fluid in a

calcified mass in one patient.

In one patient with bilateral pleural effusion.

pericardiac thickening was also found (Fig. 5).

In one patient with a lobar pneumonia and

pleural effusion, an anterior chest wall abscess

and spinal tuberculosis were seen as a low-

attenuation soft-tissue mass with rim enhance-

ment and bone destruction. Chest radiographs

in these patients failed to detect the pericardiac

on chest wall involvement.

In eight of 41 patients, a diagnosis of tuber-

culosis was suggested only after a CT scan

revealed low-attenuation nodes with rim

enhancement. calcifications. and nodules of

bronchogenic spread or miliary nodules. These

findings were not seen on chest radiographs. In

nine (41 %) of 22 patients with complications

oftubenculosis. a CT scan detected the compli-

cations, which were missed on chest radio-

graphs. In 15 (37%) of 41 patients. a CT scan

provided information that altered the clinical

management of the disease. Antituberculous

therapy was started before bacteriologic confin-

mation in eight patients with clinically sus-

pected tuberculosis. steroid therapy was

combined with antituberculous therapy in five

patients with bronchial tuberculosis, and surgi-

cal intervention was performed in two patients

with pleural and chest wall tuberculosis.

Discussion

Lymphadenopathy with or without a con-

comitant parenchymal abnormality is a radio-

logic hallmark of primary tuberculoosis in

childhood. Enlarged lymph nodes or parenchy-

mal abnormality. although almost always

present in pulmonary tuberculosis in children,

may be difficult to identify even on high-qual-

ity chest radiographs. A CT scan can be used to

reveal on confirm the adenopathy or parenchy-

mal lesions [12]. In our study. chest radio-

graphs failed to reveal the adenopathy in 21%

of patients (seven of 34) and the parenchymal

abnormality in 35% of patients ( I I of 3 1 ). The

lung lesions were often seen with a CT scan in

areas of greatest ventilation: the middle lobe,

the lower lobe, or the anterior segments of an

upper lobe. This pattern differs from reactiva-

tion tuberculosis in adults, which is typically

located in the apical or posterior segment of the

upper lobes [81.Characteristically. an enhanced CT scan

shows enlarged nodes with low-attenuation

centers. which represent caseation necrosis and

peripheral rim enhancement representing

inflammatory hypervascularity in granuloma-

tous tissue [13]. These CT findings were seen in

85% of patients (29 of 34) with tuberculous

lymphadenitis in this study and are not different

from those reported in adults [1 31. Calcification

within the nodes was not commonly seen in our

studies (five [ 15%] of 34 patients); however. if

calcification was present. it could be a diagnos-

CT of Pulmonary Tuberculosis in Children

AJR:168, April 1997 1009

tic clue for tuberculosis. We think that CT scans

can be useful in differentiating tuberculosis from

other causes of lymphadenopathy in childrenbecause the CT findings are rarely seen in other

diseases such as lymphoma, metastasis, sarcoi-

dosis, coccidioidomycosis, and histoplasmosis

I 13, 14]. In HIV-positive patients. findings of

low-attenuation nodes are considered sufficient

to warrant instituting empirical antitubenculous

therapy [1 1].

Homogeneous. dense, and well-defined air

space consolidation is a typical CT appearance

of primary tuberculosis [9]. However, low-

attenuation areas representing caseation necrosis

or calcifications can be seen within consolida-

tion (30% of the patients in our study). The

necrosis and liquefaction in areas of pneumonic

consolidation can progress to extensive lung

damage [15, 16], as occurred in one infant in

this study. CT is particularly sensitive in identi-

fying the presence of endobronchial spread of

disease and nodular densities that vary in size

and are seen in up to 95% ofpatients with newly

diagnosed reactivation tuberculosis [10]. These

findings were seen in 29% ( 12 of 41 ) of thepatients in our study. Although a similar appear-

ance can be seen in patients with atypical myco-

bacterial or bacterial bnonchopneumonia, we

think that these CT findings, if present, can be

helpful in diagnosing tuberculosis in children.

CT was also helpful in diagnosing miliaiy tuber-

culosis in patients with normal or equivocal

chest radiographic findings [17].

The advantages of CT over chest radiographs

in defining the extent of tuberculous disease and

its complications (bronchial, pleural, pericardiac,

and chest wall tuberculosis) have been well doc-

umented in the literature [18-20] and were con-

fumed in our study. In nine patients, CT

revealed the complications of tuberculosis,

missed on chest radiographs, and indicated the

need for two patients to undergo surgery. If pleu-

ral thickening is shown on a plain radiograph,

CT is useful for determining whether the thick-

ening represents pleural thickening or chronic

loculated effusion, which usually needs decorti-

cation [20], as in one patient in our study.

In the evaluation of children with known or

suspected pulmonary tuberculosis, CT scans

cannot be routinely recommended because of

the high costs. the need for sedation. and the

risks involved in administering a contrast

medium. However, in certain circumstances,

the additional information provided by CT can

suggest the diagnosis of tuberculosis. as

occurred in eight patients in our study. and can

alter the clinical management. as for I 5 patients

in the study. We recommend CT when the

radiographic findings are normal or inconclu-

sive and tuberculosis is suspected clinically; we

also recommend CT and when complications

of tuberculosis are suspected.

In conclusion, the advantages and comple-

mentary nature of CT in evaluating children

with pulmonary tuberculosis are in the detec-

tion of disease in normal on equivocal chest

radiographs; in the characterization of lesions

by showing low-attenuation nodes with rim

enhancement, calcifications, and nodules of

bronchogenic spread or miliary nodules; and in

defining the extent of disease and its complica-

tions with sectional imaging capability.

Although chest radiography remains the fore-

most imaging technique in the evaluation of

pulmonary tuberculosis in children, CT can be

useful in certain circumstances and can provide

important information in the diagnosis and

management of the disease.

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