A 40-year-old female presents with fever, pleuritic chest pain and abdominal pain. She is too unwell to provide a history when she first arrives.
Initial vital signs include: HR 120, SBP 85, Sats 82% RA, RR 40, temp 38.1°C (100.6°F)
A portable CXR is performed
Describe and interpret the CXR
The CXR shows patchy consolidation with several areas of cavitation in the right lung.
Due to progressive respiratory distress, she requires intubation, and then proceeds to have a CT pulmonary angiogram and a CT abdomen.
Describe and interpret the CT findings
The CT demonstrates pulmonary septic embolus.
CT of the lungs confirms the peripheral wedge-shaped consolidation and nodules with cavitation. These represent infection seeded via the pulmonary artery. Development of multiple predominantly peripheral nodules, with cavitation in a patient with sepsis is highly suspicious for the pulmonary septic embolus.
Classically the ‘feeding vessel sign’ is associated with the condition. It appears as a distinct vessel leading directly into the centre of a nodule.
A macroscopic thrombus is usually not seen in the pulmonary arteries. These nodules can further develop into abscesses or even rupture and cause pneumothorax.
Differential diagnosis for similar appearance of nodules with cavitation include cavitating metastasis and Wegener granulomatosis (Granulomatosis with polyangiitis (GPA)).
On the abdominal images we see a peripheral hypodensity in the lower pole of the spleen, this is due to splenic infarct, again from septic embolus.
Further history was obtained for this patient, it was discovered that she had recent IV drug use as well as previous valvuloplasty for tricuspid valve endocarditis.
This clinical picture is consistent with active infective endocarditis causing septic emboli to both her lungs and spleen. The diagnosis of endocarditis was subsequently confirmed with echocardiogram.
Other sites of septic embolisation include the brain (most common) and kidneys. Less common sites to consider are peripheral arteries, coronary circulation and the eyes.
The presence of emboli to both the left sided circulation (spleen) and right side (the lungs) suggests involvement of valves in both the left and right heart (or as a less likely alternative, the presence of a septal defect).
- Dodd JD, Souza CA, Müller NL. High-resolution MDCT of pulmonary septic embolism: evaluation of the feeding vessel sign. AJR Am J Roentgenol. 2006 Sep;187(3):623-9.
TOP 100 CT SERIES
Emergency Medicine Education Fellow at Liverpool Hospital NSW. MBBS (Hons) Monash University. Interests in indigenous health and medical education. When not in the emergency department, can most likely be found running up some mountain training for the next ultramarathon.
Sydney-based Emergency Physician (MBBS, FACEM) working at Liverpool Hospital. Passionate about education, trainees and travel. Special interests include radiology, orthopaedics and trauma. Creator of the Sydney Emergency XRay interpretation day (SEXI).