1. Differential Diagnosis of mass-like density in lower hemithorax
Intern 張敬弘

2. Mass-like density in lower hemithorax
Subpulmonic pleural effusion
Lobar atelectasis
Paralysis of hemidiaphragm
Eventration of diaphragm
Tumor of diaphragm
Subphrenic mass effect
Pericardial cyst or fat pad
Posterior mediastinal mass
Hernias

3. Mass-like density in lower hemithorax
Pericardial cyst or fat pad
Posterior mediastinal mass
Subpulmonic pleural effusion
Lobar atelectasis
Paralysis of hemidiaphragm
Eventration of diaphragm
Tumor of diaphragm
Subphrenic mass effect
Hernias

4. Pericardial cyst or fat pad
No air
Generally right-sided
Fluid or fat density with cross-sectional imaging

5. Posterior mediastinal mass
Neurofibroma, Schwannoma
Usually paraspinal, Bochdalek hernias usually more lateral in location
Germ cell tumor

6. Mass-like density in lower hemithorax
Pericardial cyst or fat pad
Posterior mediastinal mass
Subpulmonic pleural effusion
Lobar atelectasis
Paralysis of hemidiaphragm
Eventration of diaphragm
Tumor of diaphragm
Subphrenic mass effect
Hernias

7. Subpulmonic pleural effusion
The “dome” of pseudodiaphragm migrates toward the costophrenic angle and flattens
Fluid may extend into fissures
Decubitus chest radiographs can usually distinguish pleural fluid from true elevation

8. Lobar atelectasis
Hilar displacement
Mediastinal shift

9. Mass-like density in lower hemithorax
Pericardial cyst or fat pad
Posterior mediastinal mass
Subpulmonic pleural effusion
Lobar atelectasis
Paralysis of hemidiaphragm
Eventration of diaphragm
Tumor of diaphragm
Subphrenic mass effect
Hernias

10. Eventration of diaphragm
Size: typically 1/3 projected lung height
Lateral view: anterior portion and dome ↑
Intact but thinned out muscle and tendon

11. Phrenic nerve paralysis
Fluoroscopic “sniff” test or ultrasound dynamically assessfunction of muscle
During a strong sniff, the paralyzed muscle will elevate while the normal muscle will depress

12. Tumor of diaphragm
Mesothelioma
Fibroma
Lipoma
Lymphoma
Metastasis

13. Mass-like density in lower hemithorax
Pericardial cyst or fat pad
Posterior mediastinal mass
Subpulmonic pleural effusion
Lobar atelectasis
Paralysis of hemidiaphragm
Eventration of diaphragm
Tumor of diaphragm
Subphrenic mass effect
Hernias

14. Subphrenic mass effect
Hepatic tumors
Hepatic abscess
Hepatomegaly
Ascites
Bowel obstruction
Pancreatic pseudocyst
Pregnancy …
Hepatic abscess

15. Hernias Hiatal hernia Bochdalek hernia Morgagni hernia
Tramatic diaphragmatic rupture with hernia

16. Hiatal hernia Congenitally large esophageal orifice
Retrocardiac air-containing masses
Common finding in adult

17. Bochdalek hernia
Maldevelopment / defective fusion of the cephalic fold of the pleuroperitoneal membranes
Posterior pleuroperitoneal hiatus
Primarily left-sided
Congenital: left 80%, right 15%, bil. 5%
Adult: left 66%, right 33%
Majority contain fat only, less commonly kidney or bowel

18. Morgagni hernia Maldevelopment of septum transversum
Anterior retrosternal or parasternal hiatus
Primarily right-sided
Majority contain omentum
May contain bowel, most commonly colon

19. Traumatic rupture History of trauma but may be remote
90% left side, size vary
Often contains bowel
Stomach > colon > small bowel > omentum > spleen > kidney > pancreas

20. The END

21. Diaphragmatic hernia Bowel loops in chest
Contralateral shift of mediastinum + heart
Complete absence of diaphragm
Absence of stomach, small bowel in abdomen