Table 2 Summary of different types of thoracic hernias, their imaging findings, mimics, and brief description of the treatment

Apical/cervical lung

CXR: lateral deviation of trachea by unilateral lucency

CT/MRI: supraclavicular protrusion of lung posterior to the subclavian vessels. Enlargement with Valsalva manoeuvre

Supraclavicular emphysema, apical bulla

Imaging follow-up in asymptomatic patients

Congenital hernias in infants may resolve spontaneously

Elective surgical repair in symptomatic patients or those with incarcerated hernia

Cervical aortic arch

CXR: absence of aortic knob, tracheal deviation to contralateral side

CT/MRI: elongated aortic arch extending into the neck

Aneurysm of carotid arteries

Vascular rings

Increased risk of dilation and aneurysm that may require follow-up imaging, endovascular or surgical repair

Intercostal

CT: protrusion of lung parenchyma or other viscera beyond the intercostal space

Chest wall emphysema

Eloesser reconstruction

No intervention for asymptomatic hernia

Elective surgical repair for incarcerated hernia

Emergent surgical repair for strangulated hernia

Sternal

CXR: lateral view may identify presternal opacity

CT: protrusion of pericardium, cardiac chambers or great vessels through the sternal dehiscence

Postoperative sternal infection, haematomas or seroma

Pericardiocutaneous fistula

Elective surgical repair with musculocutaneous grafts. Radical sternectomy for post-sternotomy mediastinitis

Spinal

CXR: widening of mediastinum, paraspinal opacity, associated vertebral anomalies

CT/MRI: protrusion of meninges with CSF and occasionally spinal cord or nerves into posterior mediastinal, pleura or chest wall

Foregut duplication Cyst

Cystic neoplasms

Elective surgical repair

Transmediastinal

CXR/CT: lung herniation across anterior-posterior junction lines

Pleural sac or fluid herniation across posterior junction line

Post-pneumonectomy

Atelectasis from bronchial obstruction

May require placement of tissue expander for bronchial narrowing/stenosis

Intrapleural

CXR: bowel loops in the hemithorax, elevated hemidiaphragm, NG tube above the left hemidiaphragm

CT:

direct sign:

Defect in the diaphragm, dangling diaphragm

Indirect: herniation of abdominal fat or viscera into the pleural cavity, collar sign

Diaphragmatic mass, lipomas

Laparotomy with repair during the acute phase

Transthoracic or thoracoabdominal approach for chronic hernia

Mediastinal

CXT: opacity at the anterior cardiophrenic angle.

CT/MRI: small defect in between pars sternalis and pars costalis with herniation of omentum or bowel loops

Pericardial cyst, prominent pericardial fat or mediastinal lipomatosis

No treatment for asymptomatic hernia

Elective repair for herniated viscera or bowel

Pericardial

CXR: air fluid level from herniated bowel in the retrosternal region

CT/MRI: herniation of abdominal organs, omentum or bowel loops into the pericardium

Pericardial haematoma, primary tumour, metastasis

Elective repair for herniated viscera or bowel

Type I hiatal hernia

Oesophagogram/ CT: displacement of oesophagogastric junction into thorax

No surgery for asymptomatic hernia

Medical treatment of reflux disease

Antireflux procedure

Type II hiatal hernia

Oesophagogram/ CT:

GE junction in normal position, fundus herniates into thorax

Epiphrenic or traction diverticulum

Oesophageal fistula

Symptomatic hernia: elective surgical repair

Type III hiatal hernia

Both GE junction and fundus herniate

Epiphrenic or traction diverticulum

Gastric or oesophageal fistula

Elective surgical repair

Type IV hiatal hernia

Other viscera also herniate in addition to stomach

Postoperative appearance after upper gastrointestinal surgery

Elective surgical repair

Sub-diaphragmatic

Extension of the abdominal wall hernia through the superficial and deep fascia into thorax

Surgically created vascular or bowel conduits

Elective surgical repair