Classifications

“Situs” describes the positioning of the cardiac atria and thoracic and abdominal viscera:

• situs solitus – the normal arrangement of thoracic and abdominal organs (eg left sided stomach, right sided liver)
• situs inversus – exact mirror image of situs solitus. (eg right sided stomach, left sided liver). Prevalence of 0.01%
• situs ambiguus – any in between configuration. Sometimes described as heterotaxy

Associations

• congenital heart disease: 3-5% incidence inpatients with situs inversus, most common associated anomaly being transposition of the great arteries (TGA).
• Kartagener syndrome: 50% of Kartagener syndrome patients have situs inversus but only 20% of patient’s with situs inversus have Kartagener syndrome.

In regards to our patient she was diagnosed with situs inversus prenatally. Post-natally, chest x-ray and abdominal ultrasound were obtained, which confirmed the diagnosis. An echocardiogram was also obtained, which demonstrated no evidence of congenital heart disease.

This case was submitted with supervision and input from:

Soni C. Chawla, M.D.
Associate Professor
Department of Radiological Sciences
David Geffen School of Medicine at UCLA
Olive View - UCLA Medical Center