Emergency and Trauma · Chest and Cardiovascular
Chest and Cardiovascular Emergency One-Liners
High-yield one-liners on emergency chest and cardiovascular imaging including pulmonary embolism, aortic syndromes, pneumothorax and cardiac emergencies.
Rapid-revision one-liners covering emergency chest and cardiovascular imaging, including pulmonary embolism, acute aortic syndromes, pneumothorax, cardiac tamponade and related critical diagnoses.
- CTPA for pulmonary embolism
- CT pulmonary angiography is the first-line investigation for suspected PE; contrast bolus timed to pulmonary arterial opacification (100-120 HU in main PA) with acquisition in a single breath-hold.
- PE clot burden assessment
- PE clot burden can be assessed using the Qanadli score or RV/LV diameter ratio; RV/LV ratio greater than 1 indicates right heart strain and adverse prognosis.
- Saddle embolus
- A saddle embolus straddles the main pulmonary artery bifurcation; it may cause acute right heart failure and haemodynamic collapse despite not always correlating with clot volume.
- Westermark and Hampton signs
- Westermark sign (regional oligemia) and Hampton hump (peripheral wedge-shaped opacity) are classic but insensitive radiographic signs of PE; present in fewer than 20% of cases.
- Aortic dissection classification
- Stanford Type A involves the ascending aorta (surgical emergency); Type B involves only the descending aorta (typically medical management unless complicated). DeBakey classification further subdivides by origin and extent.
- CT aortography protocol
- ECG-gated CTA from thoracic inlet to femoral arteries with arterial phase timing; non-contrast phase may be added to identify intramural haematoma (crescentic hyperdensity within the aortic wall).
- Intramural haematoma
- Intramural haematoma appears as a crescentic or circumferential hyperdense aortic wall thickening (>5 mm) on non-contrast CT without an intimal flap or flow in the false lumen.
- Penetrating atherosclerotic ulcer
- PAU is a focal contrast-filled outpouching through the aortic intima into a thickened, atherosclerotic wall; risk of progression to intramural haematoma, dissection or rupture.
- Tension pneumothorax
- Tension pneumothorax is a clinical diagnosis (hypotension, tracheal deviation, absent breath sounds) requiring immediate decompression; radiograph shows complete lung collapse, mediastinal shift and diaphragmatic depression.
- Pneumothorax size estimation
- BTS guidelines estimate pneumothorax size by the interpleural distance at the hilum: greater than 2 cm is considered large. ACCP uses the apex-to-cupola distance.
- Cardiac tamponade on imaging
- CT or echocardiography shows pericardial effusion with right atrial or right ventricular diastolic collapse; on CT, reflux into IVC and hepatic veins supports tamponade physiology.
- Massive haemothorax
- Massive haemothorax is defined as greater than 1500 mL or one-third of blood volume in the pleural space; CT quantifies volume and identifies the source (vascular, parenchymal or chest wall).
- Flail chest
- Flail chest is defined by fractures of three or more adjacent ribs in two or more places, creating a paradoxically moving segment; CT is superior to radiograph for detecting rib fractures and associated pulmonary contusion.
- Pulmonary contusion
- Pulmonary contusion appears as non-segmental consolidation or ground-glass opacity on CT, typically peripheral and adjacent to the site of impact; evolves over 24-48 hours.
- Boerhaave syndrome
- Spontaneous oesophageal rupture presents with pneumomediastinum, left pleural effusion and subcutaneous emphysema; CT with oral contrast confirms the diagnosis and localises the perforation.
- Superior vena cava syndrome
- SVC syndrome on CT shows extrinsic compression or thrombosis of the SVC with collateral vessel formation; most commonly caused by bronchogenic carcinoma or lymphoma.
- Pericardial rupture
- Traumatic pericardial rupture is rare but life-threatening; CT shows herniation of cardiac structures through the pericardial defect, most commonly on the left side parallel to the phrenic nerve.
- Point-of-care cardiac ultrasound
- POCUS in the emergency setting assesses pericardial effusion, RV size and function, global LV contractility and volume status; subxiphoid four-chamber view is the fastest screening window.
Caution
Aortic syndrome classification and management thresholds vary by institution and surgical capability. CTPA contrast timing and dose should follow local protocol. Always correlate imaging with haemodynamic status.
Exam pearl
In viva, always classify aortic dissection by Stanford type first, as this immediately determines surgical versus medical management. For PE, state RV/LV ratio and clot location before describing peripheral findings.
Viva questions
- What is the Stanford classification of aortic dissection and why does it matter?
- Stanford Type A involves the ascending aorta regardless of distal extent and requires emergency surgical repair due to risk of tamponade, coronary malperfusion and rupture. Type B involves only the descending aorta and is managed medically unless complicated by malperfusion, rupture or rapid expansion.
- What CT finding indicates right heart strain in pulmonary embolism?
- An RV to LV diameter ratio greater than 1 on axial CT, often with interventricular septal bowing toward the LV, IVC contrast reflux and PA enlargement. This indicates haemodynamically significant PE and adverse prognosis.
- How does intramural haematoma appear on CT?
- On non-contrast CT, intramural haematoma appears as a crescentic or circumferential hyperdense thickening of the aortic wall exceeding 5 mm. On contrast-enhanced CT, there is no enhancement within the thickened wall and no intimal flap or false lumen flow.
- What is the clinical significance of tension pneumothorax and why is it not primarily a radiological diagnosis?
- Tension pneumothorax is a clinical diagnosis characterised by hypotension, tracheal deviation, absent breath sounds and distended neck veins. It requires immediate needle decompression before imaging, as waiting for radiograph confirmation can be fatal.
- What are the CT signs of Boerhaave syndrome?
- Pneumomediastinum, left-sided pleural effusion, subcutaneous emphysema, and oesophageal wall thickening or disruption. CT with oral contrast demonstrates extravasation confirming the perforation site, most commonly the left posterolateral distal oesophagus.