Chest Radiology

1. Jayanth H Keshavamurthy. M.D.

5. •atracheal air cyst
 Apical lung hernias can be
seen on chest radiography
as lucent regions that are
continuous with the lung
parenchyma and displace
the trachea.
 Apical lung hernias
account for 20-30% of all
lung hernias.
 Surgery is only required
when apical lung hernias
result in severe symptoms
such as cough, hoarseness,
or dyspnea.
An apical lung hernia is defined as a protrusion of the lung
parenchyma and its pleural coverings through Sibson fascia covering
the superior thoracic aperture.
Apical lung hernias account for 20-
30% of lung hernias and are less
common than thoracic lung hernias,
which protrude between the ribs or
around the lateral margin of the
thorax.

7.  Situs inversus totalis is the mirror image of normal
anatomic position with the right-sided cardiac atria
in the left thorax and the right abdominal organs
located in the left abdomen and vice versa for the
left-sided cardiac atria and abdominal organs.

8.  The incidence and complexity of congenital heart
diseases increase with the amount of discordance
between the cardiac atria, cardiac ventricle, and
position of the abdominal organs.
 Situs inversus with levocardia and situs ambiguous
with asplenia have close to a 100% rate of
associated complex congenital heart disease.
 Situs inversus has a 3–5% risk of congenital heart
disease, and
 situs solitus has a < 0.8% risk of congenital heart
disease.

10.  Right Aortic Arch
 Types
 At least five different types
 Only two of importance
 Mirror Image Type — Type I
 Aberrant left subclavian — Type II
 Associated with cardiac defects 5-10% of the
time
 Tetralogy of Fallot most often (71%)
 ASD or VSD next most often (21%)
 Coarctation of aorta rarely (7%)

14.  Bochdalek hernia is the result of a diaphragmatic
defect arising from incomplete pleuroperitoneal
membrane closure in utero.
 Large Bochdalek hernias present in the neonatal
period; are most frequently left-sided and are
associated with pulmonary hypoplasia. Small
hernias are most likely to be discovered
incidentally in adulthood.
 Bochdalek hernias may contain intraperitoneal or
retroperitoneal fat as well as abdominal viscera.

15.  Congenital diaphragmatic hernia of the Bochdalek
type is much more common than a Morgagni or a
congenital hiatal hernia.
 In distinction to the Bochdalek hernia, the
Morgagni hernia classically occurs at the right
cardiophrenic angle.

18. •Differential diagnosis
•Pericardial fat pad
•Pericardial cyst
•Mediastinal lipoma
•Lymphadenopathy
•Cystic thymoma
•Bochdalek herniaDifferential Diagnosis
close
A Morgagni hernia is a rare type of hernia
accounting for 2% of congenital
diaphragmatic hernias.
Herniation through the foramen of
Morgagni results from maldevelopment of
the septum transversum and fusion failure
of the costal and sternal fibrotendinous
elements of the diaphragm.
This herniation usually occurs on the right
side.
This type of hernia often can be
asymptomatic and discovered incidentally
through imaging for unrelated problems.

19.  The incidence of congenital diaphragmatic hernias
is estimated to be 1 in 2000-5000 live births, with
Morgagni hernias accounting for approximately
2% of all cases. The other type of congenital
diaphragmatic hernia, known as Bochdalek hernia,
is primarily posterolateral and left-sided, and it
accounts for more than 95% of all cases.
 Approximately 90% of Morgagni hernias are right-
sided; 8% are bilateral, and 2% are left-sided. It is
a direct hernia because it always contains the
peritoneal sac.

24.  Congenital diaphragmatic hernias are seen in 1 of every 2000-
4000 live births. 84% are left-sided, 13% are right-sided and 2%
bilateral .
 Associations
 While a CDH can occur as an isolated condition, associated
anomalies are relatively common and include:
 pulmonary hypoplasia: also a complication
 bronchopulmonary sequestration
 aneuploidy: can be present in up to 50% of cases ref
 trisomy 13
 trisomy 18
 trisomy 21
 Turner syndrome: monosomy X
 Pallister-Killian syndrome: tetrasomy 12p
 Fryns syndrome
 Cornelia de Lange syndrome
 congenital cardiac anomalies
 neural tube defects
 anencephaly
 spina bifida

29.  The cardio-thoracic ratio (CTR) as assesed on a
chest x-ray can appear smaller with a number of
entities. They include:
 adrenal insufficiency: e.g. Addison disease
 heart transplant
 cachexic state
 senility
 malnutrition
 bulimia nervosa
 asthmatic paroxysm with emphysema
 constrictive pericarditis
 physiological factors: e.g. Valsalva manoeuver