TB in the ED
Radiology Cases in Pediatric Emergency Medicine
Volume 4, Case 6
Craig T. Nakamura, MD
Kapiolani Medical Center For Women And Children
University of Hawaii John A. Burns School of Medicine
This is a three-year old Korean male who presents
to the emergency department with respiratory distress.
Ten days ago, he had developed a cough, rhinorrhea,
sore throat, and temperature of 39.4 degrees. The
cough, rhinorrhea, and sore throat resolved after a
three day period. However, he continued to spike
fevers. Three days ago, he was seen by his primary
care physician. A PPD was placed. He was then
started on oral cefuroxime. He was previously exposed
to a grandaunt who was treated for tuberculosis in
Korea and a grandfather with a chronic cough within the
household. He has had a decreased oral intake and a
two kilogram weight loss over the previous two weeks.
Exam: VS T39.2, P148, RR68, BP 104/69. Oxygen
saturation 90% in room air (100% on 5 liters O2 by
nasal cannula). He is alert with moderate respiratory
distress. HEENT Normal. No lymphadenopathy. Neck
supple. Heart regular without murmurs. Moderately
severe chest retractions noted. Breath sounds are
decreased on the right. There is good aeration over the
left lung fields. No wheezing, rhonchi, or rales are
heard. There is dullness to percussion over the right
base. Abdomen soft, flat, bowel sounds active, without
tenderness. Extremities significant for a positive PPD.
Capillary refill < 2 seconds.
Laboratory studies: CBC WBC 9.2 with 41%
lymphs, 43% segs, 14% monos, 1% eos, 1% basos.
Hgb. 12.6, hct. 37.2. Chemistry panel is normal.
A chest radiograph is obtained.
View chest radiograph.
If you can see vertical lines on the image
(resembling stripes), these are due to an artifact of the
radiographic "grid" used on the film. This grid is very
fine and only visible on very close inspection.
Unfortunately, the scanning process enhances the
visibility of this grid. Ignore this artifact.
A PA view is shown here. His chest radiograph
demonstrates a complete opacification of the right
hemithorax with a shift of the mediastinal structures to
This patient presents with primary tuberculosis (TB)
and a pleural effusion. There are two types of
pulmonary TB: primary and postprimary. In primary
TB, the typical route of infection occurs by the
inhalation of aerosolized (two to five micron) droplets
laden with Mycobacterium tuberculosis from the cough
of a person with active disease. The mycobacteria
usually deposit in the middle or lower lobes, where they
undergo phagocytosis and multiply intracellularly. As
neutrophils arrive, tubercles are formed and the
phagocytized tubercles are carried to regional lymph
nodes. During this stage, there are both lymphatic and
hematogenous dissemination, as the primary focus of
infection becomes encapsulated and eventually
calcifies. Hypersensitivity develops over a period of two
to ten weeks. In the majority of cases, surviving
mycobacteria remain dormant.
Postprimary TB involves the reactivation of dormant
bacilli which occurs with episodes of
immunosuppression, malnutrition, or debilitation,
typically within two years following exposure. It occurs
in 5% to 15% of cases of TB. Primary and postprimary
TB differ clinically, pathologically, and radiologically.
There are five distinct radiographic presentations of
1. Parenchymal disease
4. Pleural effusion
5. Miliary disease
Parenchymal disease is seen as a unifocal
consolidation, typically involving the right lung (there are
conflicting reports as to the preference of which regions
are affected within the lung). The infiltrate is multilobar
in approximately 25% of the cases. These infiltrates
are usually homogeneous with ill-defined borders.
Lamont further subdivided the consolidations into six
types: linear interstitial, segmental or lobar
consolidation, confluent, collapse, emphysema, and
cavitation. The most common consolidation type is
linear interstitial. Air bronchograms or associated
lymphadenopathy may be present. The infiltrates clear
in about two-thirds of all cases. After an initial
paradoxical worsening of the consolidation, resolution
occurs over a period of six months to two years. In
15% of the cases, a calcified scar may persist (the
Ghon focus). For evaluation of treatment efficacy, the
parenchymal infiltrates should be followed every two to
three months until stable or cleared.
Lobar or segmental atelectasis occurs most
frequently in children under two years of age. The
atelectasis is caused by either endobronchial disease
or external bronchial compression due to hilar
adenopathy. It usually involves the anterior segment of
the upper lobe or the medial segment of the middle
lobe and will persist until the node or endobronchial
Hilar and mediastinal adenopathy can be seen in
about 96% of children with primary TB, and is
considered the radiological hallmark. The most
frequently involved nodes are the hilar and right
paratracheal. The involvement is usually unilateral and
right-sided (bilateral in 25% to 30% of cases). Often
there is an associated parenchymal infiltrate or region
of atelectasis. The lateral chest radiograph is
particularly beneficial in the evaluation of adenopathy
and should be included in the investigation of children
suspected of having TB or those in contact with adults
with TB. The adenopathy with primary TB usually
resolves without sequelae, although nodal calcification
may occur. A nodal calcification associated with a
Ghon focus is known as a Ranke complex. The
adenopathy should be monitored on an annual basis
until stable or resolved.
Pleural effusion, uncommon in infants and young
children, can be seen in adolescents and adults. It is
usually unilateral and occurs in 6% to 12% of primary
TB infections. The effusion may mask underlying
parenchymal disease. However, with appropriate
therapy, resolution is often rapid and without sequelae.
During the hematogenous stage of primary TB,
between 1% and 7% of patients will have radiographic
evidence of miliary disease. Children under two years
of age are most commonly affected, usually within six
months of infection. When symptoms begin, the chest
radiograph is typically normal. Hyperinflation may occur
during the first two weeks. This can be followed by
diffuse, small nodular opacities about six weeks after
the onset of symptoms. Left untreated, the nodules
may enlarge to about five millimeters or may coalesce
and cavitate. With proper therapy, the nodules resolve
within two to six months. Miliary calcification is
View miliary TB example.
These PA and lateral chest radiograph views are
taken in a 7-month old with miliary TB. There are
multiple small nodules throughout the lungs bilaterally.
There is a focal consolidation in the right upper lobe.
To illustrate how rapidly this can improve, examine
the follow-up chest radiographs taken three weeks after
anti-TB therapy is initiated.
View miliary TB follow-up.
Note the substantial clearing of the multiple small
nodular densities and the clearing of the right upper
The radiologic patterns observed in postprimary TB
can be divided into four categories:
1. Parenchymal disease and cavitation
2. Airway disease
3. Pleural disease
The first manifestation of parenchymal disease is a
heterogeneous poorly defined infiltrate (the exudative
lesion) within the apical/posterior segments of the upper
lobe or the superior segment of the lower lobe. This is
thought to be secondary to a higher oxygen tension or
decreased lymphatic clearance within these regions.
This may progress to lobar or lung opacifications or
may evolve into better-defined coarse reticular or
nodular opacities (the fibroproliferative lesion). The
lesion may calcify. Pleural thickening with subpleural
atelectsis and fibrosis often leads to an "apical cap" in
40% of the patients. One important point is that
disease activity cannot be assessed by radiologic
Inactive disease is defined as a stable chest
radiograph for six months and repeatedly negative
sputum cultures. Cavitation may occur in 40% to 90%
of those with parenchymal disease. The cavities are
often multiple and are between one and three
millimeters. They have thick and irregular walls, but
can become emphysematous in nature.
Airway TB manifests as bronchial stenosis, tracheal
TB, or laryngeal TB. Bronchial stenosis is the most
common of the three, and occurs in 10% to 40% of
cases of active TB. This complication is visualized
radiographically as persistent lobar or segmental
collapse, hyperinflation, or mucoid impaction. It may
lead to bronchiectasis.
The pleural disease of post primary TB occurs in 6%
to 18% of cases. These pleural effusions are often
small (as opposed to the large effusions characteristic
of primary TB) and associated with significant
Other radiographic characteristics of postprimary TB
include pseudoaneurysms which are seen as an
enlarging mass or a rapidly appearing consolidation.
Vertebral osteomyelitis may occur as well as paraspinal
and prevertebral abscesses.
Lamont AC, Cremin BJ, Pelteret RM. Radiological
patterns of pulmonary tuberculosis in the paediatric age
group. Pediatric Radiology 1986;16:2-7.
Agrons GA, Markowitz RI, Kramer SS. Pulmonary
tuberculosis in children. Seminars in Roentgenology
McAdams HP, Erasmus J, Winter JA. Radiologic
manifestations of pulmonary tuberculosis. Radiology
Clinics of North America 1995;33(4):655-676.
Ghon A. The Primary Lung Focus of Tuberculosis in
Children. London, JA Churchill, 1916.
Smuts NA, Beyers N, Gie RP, et al. Value of the
lateral chest radiograph in tuberculosis in children.
Pediatric Radiology 1994;24:478-480.
Caffey J. Primary pulmonary tuberculosis. In:
Silverman F (ed). Pediatric X-Ray Diagnosis, 8th
edition. Chicago, Year Book, 1985, pp. 1210-1227.
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