sarcoidosis chest xray and hrct findings

1. SARCOIDOSIS
By:- Dr SHUBHANKAR TYAGI

2. Sarcoidosis is a multisystemic and often chronic disease
that can involve nearly any organ. The lungs and
intrathoracic lymph nodes are the most commonly
affected structures.
Although some radiographic and CT findings are typical
for sarcoidosis, sarcoidosis cannot be diagnosed
purely based on imaging and requires complete clinical
and pathologic correlation for definitive diagnosis.
However, recognizing the characterisic imaging features
of pulmonary sarcoidosis can aid in prompt diagnosis,
leading to proper intervention. Multiple disease
processes can have similar appearances to
sarcoidosis, which can confound diagnosis.

7. Radiological features of Sarcoidosis

8. Stage I: Hilar and
mediastinal lymph
node enlargement
without parenchymal
abnormality.

9. Stage-2
Posteroanterior chest radiograph in a man with
sarcoidosis shows right paratracheal, aorticopulmonary
window, and symmetric bilateral hilar lymph node
enlargement and small round and irregular opacities in
the upper lung zones. Note medial deviation of the gastric
bubble owing to splenomegaly

10. Stage-3
Posteroanterior chest
radiograph in a man with
sarcoidosis shows a
reticulonodular pattern
involving mainly the upper
and middle lung zones.
There is no evidence of
hilar or mediastinal lymph
node enlargement.

11. Stage IV: Advanced
fibrosis with evidence
of reticulation,
architectural distortion,
hilar retraction and
ocassionally
honeycombing.

13. LYMPHADENOPATHY
The most common radiographic finding is well-defined
mediastinal and hilar lymphadenopathy which occurs in
an estimated 95% of cases. The classically described 1-2-
3 pattern, also known as the Garland triad, is the
combination of right para-tracheal, right hilar , and left
hilar lymph node enlargement.
Additional studies have shown that the most common
radiographic pattern shows left-sided mediastinal nodes,
particularly aortico-pulmonary window lymph nodes, in
addi-tion to bilateral hilar and right paratracheal lymph
nodes. This pattern is known as the more aptly
named “1-2-3-4 pattern”

15. MICRONODULES
Sarcoid granulomas are microscopic in size yet
coalesce to form micronodules visible by CT. Opacities
less than 3 mm are referred to as micronodules.
Small nodules are the most commonly seen
parenchymal abnormality in sarcoidosis. The
development of granulomas in pulmonary sarcoidosis
has been described to follow a perilymphatic distribution,
with predominance in the parahilar peribronchovascular
interstitium, the peripheral subpleural interstitium . A mid
and upper lung zone predominance of nodules is
typical. The distribution is often patchy.
These micronodules are also known to group in the
periphery of the lung, known as the ‘sarcoid cluster’ sign.

19. LARGE NODULES AND MASSES
Nodules are rounded pulmonary opacities measuring up to
3 cm in diameter. A lesion greater than 3 cm is a mass.
Nodules and masses are seen in approximately 15–25% of
patients with parenchymal abnormalities. As the nodules
continue to coalesce, they form larger opacities, which may
appear masslike. These large nodules and masses can
be found in both the parahilar and peripheral regions. Air
bronchograms may also be seen, which give the appearance
of consolidation. On CT, a mass surrounded by smaller
satellite nodules has been termed the “galaxy” sign. The
galaxy sign is often seen in patients with mass-es who have
sarcoidosis, but is not specific to the disease. In rare
instances, the large nodules and masses in sarcoidosis can
cavitate and may lead to secondary spontaneous
pneumothorax

21. RETICULATION AND FIBROSIS