SPEAKER: DR. MOH’D RAMZY (Quality Department Coordinator, MGH)

2. CRITICAL CHEST RADIOGRAPHS
CAN'T-MISS DIAGNOSES
BY DR. MOHAMED R. YOUSSEF
ER RESIDENT,QUALITY COORDINATOR MGH
SOURCE :-MEDSCAPE.COM

5.  Chest radiographs are the most common radiologic
tests performed in hospitals and emergency
departments.
 Although radiologists are responsible for the final
interpretation of studies, many chest radiographs are
first viewed by non-radiologists.
 All physicians should be able to quickly and
accurately identify a wide number of critical findings to
help identify patients who need subsequent emergent
care.

7. This image is of an individual with a major
pneumoperitoneum showing the outline of the liver
and spleen

8. pneumothorax

9.  A pneumothorax occurs when air fills the space
between the parietal and visceral pleura of the lungs.
 A primary spontaneous pneumothorax occurs without
any underlying lung disease and in the absence of an
inciting event,
 while a secondary spontaneous pneumothorax occurs in
people with underlying parenchymal lung disease (eg,
chronic obstructive pulmonary disease, pulmonary
fibrosis).
 On a chest radiograph, a pneumothorax may be
identified by a discrete shadowed line beyond which
no lung markings are present (arrows).
 They most commonly occur in the lung apices, which
are the least dependent part of the lung.
 However, on supine radiographs, pneumothoraces may
be subpulmonic or anteromedial in location. Comparison
between inspiratory and expiratory films may aid in
detection.

10. tension pneumothorax

11.  A tension pneumothorax is the accumulation of air
under pressure in the pleural space.
 It develops when injured tissue creates a one-way valve
for air to enter, but not leave, the pleural space.
 Diagnosis should be made on clinical grounds by
contralateral tracheal deviation, ipsilateral
hyperresonance to percussion, ipsilateral decreased
breath sounds, distended neck veins, and
hypoperfusion.
 The typical radiographic findings are ipsilateral lung
collapse (white arrow) with widened intercostal spaces
and contralateral mediastinal deviation (red arrow).
With a left hemithorax, the left hemidiaphram may be
depressed, but the liver prevents this from developing
on the right side.

12. Pneumomediastinum

13.  Pneumomediastinum is free air in the mediastinal
structures. It most commonly occurs following trauma or
iatrogenic injury to the esophagus or adjacent alveoli.
On chest radiography, free air may outline anatomic
structures.
 Common findings are a thin line of radiolucency that
outlines the cardiac silhouette (white arrow), vertically
oriented streaks of air in the mediastinum, a double
bronchial wall sign, or lucency around the right
pulmonary artery, the "ring around the artery" sign.
 Air is most easily detected retrosternally on lateral chest
radiographs. Air is fixed in a pneumomediastinum and
does not rise to the highest point

15. Airway foreign body

16.  Airway foreign bodies are most often found in
pediatric patients.
 The most common site of foreign bodies is the right
mainstem bronchus due to its posterior location,
shallow angle to the trachea, and wide diameter.
The density of the ingested item will determine
whether it can be directly identified on radiographs.
 Indirect signs of ingestion include focal
overinflation if there is partial obstruction or
atelectasis if there is more complete obstruction.
 The image shown demonstrates a radiopaque
earring backing (arrow) lodged in the right
mainstem bronchus of a child.

18.  Pneumoperitoneum refers to air within the peritoneal
cavity, most commonly from perforation of an
abdominal viscus.
 Air will accumulate in the least dependent portion of the
abdominal cavity. During upright chest radiographs, air
will separate the liver, spleen, and intestines from the
diaphragm producing dark crescents (arrows shown).
 To ensure adequate air migration, patients should be
kept upright for at least 5 minutes before the image is
taken. Sometimes, a double-wall, or Rigler's,sign can
be seen which refers to internal and external air
outlining the intestinal wall.

20. Green arrows = luminal surface;
white arrows = peritoneal surface

21. Pericardial effusions

22.  Pericardial effusions result from the
accumulation of fluid within the pericardial space.
 The classic finding on a chest radiograph is an
enlarged cardiac silhouette,
the so-called water-bottle heart.
 However, if the fluid accumulates rapidly, then
minimal cardiomegaly may be present. Other
potential findings include pleural effusion and
rarely pericardial calcifications.

23. Ards

24.  Acute respiratory distress syndrome is defined as
acute onset, a PaO2 to FIO2 of 200 mm Hg or less,
bilateral chest radiograph infiltrates, and a pulmonary
arterial wedge pressure of 18 mm Hg or less or no clinical
signs of left atrial hypertension.
 The most common findings on chest radiographs are
bilateral, predominately peripheral, asymmetric
consolidations with air bronchograms (arrows shown).
Septal lines and pleural effusions are uncommon findings.
Early findings during the exudative phase are bilateral
consolidations that obscure the pulmonary vascular
markings. These opacities extend to more extensive diffuse
consolidations that are typically asymmetric. In the
subsequent fibrotic stage, a diffuse interstitial appearance
may develop. Most radiographic abnormalities begin to
resolve after 10-14 days if the patient survives.

25.  Four main criteria for ARDS:
 Acute onset
 Chest X-Ray: Bilateral diffuse infiltrates of the lungs
 No cardiovascular lesion
 No evidence of left atrial hypertension: PaO2/FiO2 ratio
equal to or less than 200 mmHg.

27. Thoracic aortic aneurysms

28.  Thoracic aortic aneurysms are defined as a greater
than 50% aneurysmal dilatation of the normal
ascending thoracic aorta, aortic arch, or descending
thoracic aorta.
 The descending thoracic aorta is the most common
site. On chest radiographs, the most common findings
are a widening of the mediastinal silhouette (white
arrow), enlargement of the aortic knob, and tracheal
displacement (red arrow).
 Other radiographic findings include a double-opacity
appearance to the aorta representing true and false
lumens, localized bulges along the aortic contour, and
a disparity in the caliber of the descending and
ascending aorta

29. Diaphragmatic hernia

30.  Diaphragmatic hernias are caused when a defect in
the diaphragmatic wall allows for the herniation of
abdominal contents into the thoracic cavity. The majority
of tears are on the left side.
 On chest radiographs, asymmetry of a hemidiaphragm
or changing diaphragmatic levels may be present
(arrow). Gas-filled organs or a nasogastric tube within
the thoracic cavity will confirm the diagnosis.
 Solid abdominal organs will appear as mushroom-
shaped homogeneous opacities. Potential
misdiagnosis can occur in the case of diaphragmatic
paralysis or after lung reduction surgery

31. Thoracic aortic aneurysms

32.  Congestive heart failure is a clinical syndrome in which
the heart fails to adequately pump blood to metabolizing
tissues.
 A number of typical findings may be present on a chest
radiograph. With cardiomegaly, the cardiothoracic ratio
increases to greater than 50% on a posterior-anterior chest
radiograph (white lines).
 Kerley B lines may be present on the lung periphery that are
the result of interlobular septal thickening.
 Accumulated pleural fluid may blunt the costophrenic
angles (red arrow) or cause large pleural effusions.
 Pulmonary edema may cause bilateral increased lung
markings in a perihilar, or bat-winged, distribution.
 Increased pulmonary capillary pressure causes the upper
lobe vessels to be equal or larger in caliber than the lower
lobe vessels, referred to as cephalization.

33. Aspiration pneumonia

34.  Aspiration pneumonia is an infectious process caused
by aspirated oropharyngeal flora or gastric contents. It
is differentiated from aspiration pneumonitis, which is
caused by direct chemical insult from the aspirated
material. Typical findings on chest radiographs are
bilateral opacities in the middle or lower lung zones
(shown). In the acute phase, transient infiltrates or lobar
consolidation may be present, while chronic aspiration
may appear as a solidified mass

35. Ett

36.  Although the initial placement of an endotracheal tube is
evaluated with bilateral auscultation and usually a
carbon dioxide detector, a chest radiograph is routinely
performed for confirmation. Endotracheal tubes have a
radiopaque strip impregnated along one side to aid in
evaluation. The tip of the tube should be 2-6 cm
(double-headed arrow) above the carina (angled lines).
At this position, the tip will provide adequate ventilation
when the tube is shifted during neck flexion or
extension. If the tube is positioned too deeply, then
there may be selective intubation of only one lung,
which can lead to complete atelectatic collapse of the
contralateral lung.

38. A hydropneumothorax

39.  A hydropneumothorax refers to the presence of
both air and fluid within the pleural space. It may
develop after esophageal rupture (shown), trauma,
infection with a gas-forming organism, development
of a bronchopleural fistula, or iatrogenic after
surgery. An upright chest radiograph will typically
show a horizontal air-fluid level that extends across
the whole length of the hemithorax (arrow). For an
air-fluid level to be present, there must be both air
and fluid within the pleural space.

41. A hydropneumothorax

42.  A left ventricular aneurysm is an uncommon
complication after a myocardial infarction, in which
weakened myocardial tissue creates a distinctive
outpouching of the left ventricle.
 On chest radiographs, the total heart size will be
enlarged with a prominent bulging of the left heart
border.
 On lateral radiographs, there will be distortion of the
lateral heart profile, either anterior or posterior (shown)
depending on the region of outpouching.
 In some cases, a rim of calcification may be present
outlining the aneurysm itself.
 Image courtesy of Dr. Eugene C. Lin.