Step by step evaluation by HRCT of pediatric ILD.

1. The road to HRCT
evaluation of
Dr/Ahmed Bahnassy
Consultant Radiologist
Riyadh Military Hospital

2. Does chILD differ from adILD?
1. Differences in the immune system
responces, cytokine and growth factors
2. Histologic classification differs significantly
3. Specific types presented at children not
adults
4. Rarer and less stereotyped than adult ILD
5. More difficult to treat than adults.

3. Examples of common terms of chILD
DIP Desquamative interstitial pneumonitis
CIP Chronic pneumonitis of infancy
NSIP Non-specific interstitial pneumonitis
FB/LIP Follicular bronchiolitis /lymphoid
Interstitial Pneumonia
OP Organizing pneumonia (old BOOP)
PIG Pulmonary interstitial glycogenosis
NEHI Neuroendocrine cell hyperplasia of
infancy
* UIP: Usual interstitial pneuminitis is rare in children.

4. Diagnostic journey of chILD?
• First round investigations:
1. Imaging (HRCT)
2. Lung functions (DLCO)
3. Oxygen saturation (rest /exercise)
4. Blood tests (CBC, ESR, Immune, Serology
and PCR, RAST, ACE, HIV)
5. Resp secretions cultures/PCR
6. Sweat chloride test.
7. pH study/Contrast swallow
8. ECG and ECHO
9. Ciliary Brush Biopsy
10. Urine for CMV PCR

5. • Second round
• Third round
investigations:
investigations:
1. Lung biopsy
1. Upper GI study for ? H type (Transbronchial,percutaneous,
fistula thoracoscopic, open lung) CT
2. Bronchoscopy and BAL for guided from affected patch and
cytology (LCH, iron laden unaffected patch.
macrophages, PAP) and • Special stains (eg. Bompesin or
cultures PAS)
• Immunoblotting for sufactant
3. Videofluroscopy for aspiration proteins at lung biopsy
evidence • Electron microscopy study of
4. Cardiac Cath biopsy
5. Detailed lymphocyte function • DNA for mutations in SPB, SPC
tests and ABCA3
6. TB –Elispot test

6. HRCT in children
SPL
parameters

7. Glossary of
Terms of HRCT
Same terminology for both adults and pediatrics

8. beaded septum sign
This sign consists of irregular
and nodular thickening of interlobular
septa reminiscent of a row of beads

9. bronchiectasis
Bronchiectasis is irreversible
localized or diffuse bronchial dilatation,
usually resulting from chronic infection,
proximal airway obstruction, or
congenital bronchial abnormality

10. signet ring sign
This finding is composed of
a ring-shaped opacity representing a dilated
bronchus in cross section and a
smaller adjacent opacity representing
its pulmonary artery, with the combination
resembling a signet (or pearl) ring.

11. bronchiolectasis
Bronchiolectasis is defined
as dilatation of bronchioles. It is caused
by inflammatory airways disease (potentially
reversible) or, more frequently,
fibrosis

12. bronchocele
A bronchocele is bronchial
dilatation due to retained secretions
(mucoid impaction) usually caused by
proximal obstruction, either congenital
(eg, bronchial atresia) or acquired (eg,
obstructing cancer)

13. bronchocentric
This descriptor is applied to
disease that is conspicuously centered
on macroscopic bronchovascular bundles
Examples of diseases with
a bronchocentric distribution include
sarcoidosis , Kaposi sarcoma ,
and organizing pneumonia .

14. broncholith
A broncholith, a calcified
peribronchial lymph node that erodes
into an adjacent bronchus, is most often
the consequence of Histoplasma or tuberculous
infection.

15. cavity
A cavity is a gas-filled space, seen as a
lucency or low-attenuation area, within
pulmonary consolidation, a mass, or a
nodule

16. crazy-paving pattern
This pattern appears as
thickened interlobular septa and intralobular
lines superimposed on a
background of ground-glass opacity , resembling irregularly shaped paving
stones.

17. cyst
A cyst is any round circumscribed
space that is surrounded by an
epithelial or fibrous wall of variable
thickness

18. consolidation
Consolidation refers to an
exudate or other product of disease that
replaces alveolar air, rendering the lung
solid (as in infective pneumonia).

19. ground-glass opacity
Area of hazy increased lung
opacity, usually extensive, within which
margins of pulmonary vessels may be
indistinct. On CT scans, it appears as
hazy increased opacity of lung, with
preservation of bronchial and vascular
margins

20. halo sign
The halo sign is a CT finding
of ground-glass opacity surrounding a
nodule or mass..It refers to severe pulmonary infection..first
described with invasive aspergillosis in leukemic patients .

21. reversed halo sign
The reversed halo sign is a
focal rounded area of ground-glass
opacity surrounded by a more or less
complete ring of consolidation .
A rare sign, it was initially reported to
be specific for cryptogenic organizing
pneumonia but was subsequently
described in patients with paracoccidioidomycosis

22. honeycombing
Honeycombing represents
destroyed and fibrotic lung tissue containing
numerous cystic airspaces with
thick fibrous walls, representing the late
stage of various lung diseases, with
complete loss of acinar architecture.
The cysts range in size from a few millimeters
to several centimeters in diameter, and
have variable wall thickness.

23. parenchymal band
It is a linear opacity, usually
1–3 mm thick and up to 5 cm long that
usually extends to the visceral pleura
(which is often thickened and may be
retracted at the site of contact).
It reflects pleuroparenchymal fibrosis
and is usually associated with distortion
of the lung architecture.

24. mycetoma
A mycetoma is a discrete
mass of intertwined hyphae, usually of
an Aspergillus species, matted together
by mucus, fibrin, and cellular debris colonizing
a cavity, usually from prior fibrocavitary
disease (eg, tuberculosis or
sarcoidosis)

25. tree-in-bud pattern
The tree-in-bud pattern represents
centrilobular branching structures
that resemble a budding tree. The
pattern reflects a spectrum of endo- and
peribronchiolar disorders, including mucoid
impaction, inflammation, and/or fibrosis

26. Nice summary From Dr/Richard
Webb

27. Secondary Pulmonary Lobule
disease patterns
Same usage for both adults and pediatrics
with different significance

28. The “Unit” of the lung
The secondary pulmonary lobule is a fundamental unit of
lung structure, and it reproduces the lung in miniature.
Airways, pulmonary arteries, veins, lymphatics, and the
lung interstitium are all represented at the level of the
secondary lobule.

29. Anatomy of SPL

30. I-Perilobular pathology

31. Lymphangitic carcinomatosis

32. Sarcoidosis

33. Idipathic pulmonary fibrosis(rare in
children)
• Typical HRCT
findings in
adults.

34. II-Centrilobular pathology.

35. Hypersensitivity pneumonitis

36. Cellular bronchiolitis

37. Tree-in-bud
in patients with a centrilobular
distribution of nodules, if the tree-inbud
sign can be recognized the differential
diagnosis is limited:
Endobronchial spread of tuberculosis
or nontuberculous mycobacteria
Bronchopneumonia,
infectious bronchiolitis
Cystic fibrosis ,
bronchiectasis of any
cause
diffuse panbronchiolitis
asthma or allergic bronchopulmonary
aspergillosis , constrictive
bronchiolitis , follicular bronchiolitis,
bronchioloalveolar carcinoma, and
intravascular metastases.

38. Centrilobular emphysema
Centrilobular (centriacinar) emphysema
is characterized histologically
by areas of lung destruction occurring
in relation to centriacinar
bronchioles and, therefore, is located
in the center of the secondary lobule
or surrounding the centrilobular region

39. III-Panlobular pathology

40. Lobular Process
Pneumonia
Hypersensitivity pneumonitis

41. Headcheese sign in
hypersensitivity pneumonitis
The headcheese sign is indicative of
mixed infiltrative and obstructive
disease, usually associated with
bronchiolitis
The most common causes of this pattern
are hypersensitivity pneumonitis, desquamative
interstitial pneumonia or respiratory
bronchiolitis–interstitial lung disease,
sarcoidosis, and atypical infections
with associated bronchiolitis, such as occurs
with M pneumoniae.

42. Consider the distribution of the
pathology
Same principle for both adults and pediatrics.for DD

43. Cranio-caudal axis
Apical
middle Basal

44. Transverse axis
Peripheral
Central
Or both

45. Antero-posterior axis
Anterior Posterior
Or both