Case Study

A. Swartbooi

Diagnostic Radiology, UFS

9 March 2012

Patient Info

• 46 yr old male pt

• Known cardiac pt

• Previous Mitral valve replacement

• Complaint of dyspnoea and orthopnoea

Clinical Presentation

• Chronically ill (RVD on Rx)

• Pulse & Temp N

• BP 110/80

• Blood results N

ImagingCXR

ImagingCXR

• Findings:– Dextrocardia– Cardiomegaly– Post Sternotomy wires– Right gastric air bubble– Left sided liver – Left lower pleural disease

ImagingHeart Sonar

• Findings– Dextrocardia– Global hypokinesia– EF 32%

Diagnosis

• Dextrocardia with situs inversus

Investigations

• Further evaluation in pt with abovementioned chest findings include:– Abdominal ultrasound

• If inconclusive– CT abdomen– MRI– Angiography

Imaging

• Critical structures for evaluation of situs– Cardiac apex

– Atria

– Lungs (bi- or trilobed)

– Subdiaphragmatic venous Drainage

– Aorta relative to midline

– Stomach position (? malrotation)

– Liver and gallbladder

– Spleen (presence, appearance, number)

Imaging modalities

• Chest x-ray– Plain chest and abdominal x-rays are the first

imaging modalities– Presence or absence of normal situs

• Evaluate heart

• Stomach air bubble

• Liver outline

Imaging modalities

• Ultrasound– Evaluate intra-abdominal solid organs

• Spleen

• Liver

– Vasculature• Relation of large vessels

Imaging modalities

• Transthoracic echocardiography – Directly visualize cardiovascular anomalies

• CT

• MRI

• Angiocardiography (Less commonly used)

Introduction

• Situs anomalies are often confusing, in part because of the overlapping features of some anomalies

• NB to understand the terminology

• Situs refers to the position of the heart and viscera relative to midline.

Terminology

• Situs Solitis

• Situs inversus

• Situs ambiguous/Heterotaxy

Situs Solitus

• Situs solitus – Represents the normal position of the heart and

abdominal viscera, with the cardiac apex, spleen, stomach, and aorta located on the left and the liver and inferior vena cava (IVC) located on the right

– Congenital heart disease occurs in less than 1% of individuals with situs solitus

– In case of dextrocardia 95% chance of CHD

Situs Solitus

Situs Inversus

• Situs Inversus– Indicates mirror-image location of the organs

compared to situs solitus– NB to recognize

• May help avoid mishaps at surgery or other interventions, particularly in the emergency setting

– Two major subcategories • Situs inversus with dextrocardia

• Situs inversus with levocardia

Situs Inversus

Situs Inversus

• Situs inversus with dextrocardia– Situs inversus totalis– More common – Heart and viscera relative to situs solitus– Cardiac apex, spleen, stomach, and aorta

located on the right and the liver and IVC located on the left

– 3-5 % chance of CHD

Situs Inversus

Situs Inversus

• Situs inversus with levocardia– Extremely rare– Mirror-image location of the viscera relative to

situs solitus and a left-sided cardiac apex– 95 % chance of CHD

Heterotaxy

• Heterotaxy syndrome– Rare condition that occurs in approximately

0.8% of patients with congenital heart disease– Abnormal arrangement of organs and vessels as

opposed to the orderly arrangement typical of situs solitus and situs inversus

Heterotaxy

• Patients with heterotaxy syndrome have a high probability of having severe complex cardiovascular anomalies (50 – 100%)

• Characterized not by a single set of abnormalities but by a spectrum of abnormalities

• Encompasses 2 groups of diseases• Asplenia

• Polysplenia

Heterotaxy

• Situs ambiguous with asplenia• aKa Right isomerism or bilateral right-sidedness• Findings include

– Bilat Trilobed lungs (minor fissures bilat)

– Eparterial bronchi

– Bilat left atria

– Central liver

– Stomach position indeterminate

– Absent spleen

– IVC and Aorta on same side of vertebra **

Heterotaxy

Heterotaxy

• Situs ambiguous with asplenia– 99%–100% prevalence of congenital heart disease

– Common cardiac anomalies• Common atrioventricular canal

• Univentricular heart

• TGA

• TAPVR

– More in males

– Death in 1st yr of life up to 80%

– Asplenia related to greater risk for sepsis• Carefull search for spleen NB

Heterotaxy

• Asplenia

Heterotaxy

• Situs ambiguous with polysplenia• aKa Left isomerism or bilateral left-sidedness• Findings include

– Bilat bilobed lungs

– Bilat pulm atria

– Central liver

– Stomach position indeterminate

– Multiple spleens

– IVC interuption with continuation of azygos system

• No single anomaly is pathognomonic

Heterotaxy

Heterotaxy

• Situs ambiguous with polysplenia– Cardiac anomalies less common and less

complex (50-90%)– Most common cardiac anomalies

• PAPVR

• ASD

• Atrioventricular canal

– More in females

Heterotaxy

• Polysplenia

Summary

Summary

• Situs anomalies are often detected incidentally, with ⇧ frequency, in adults during imaging evaluation for unrelated conditions

• It is important for radiologists to become familiar with these anomalies, the spectrum of their manifestations, and their significance

• Not all patients with heterotaxy present with the classic features of either asplenia or polysplenia

Summary

• Nb to utilize an individualized approach in these patients reflecting the unique anatomy

– eg. Heterotaxy syndrome (bilateral bilobed lungs, levocardia, left sided malrotated stomach)

• A complete, correct anatomic diagnosis cannot only lead to earlier intervention, but also provide some indication of prognosis

THANK YOU

References

• RadioGraphics 2002; 22:1439–1456

• RadioGraphics 1999; 19:837-852

• American Journal of CardiologyVolume 81, Issue 2, Pages 188-194 , 15 January 1998

• Dahnert. Radiology Review Manual, page 593-594

• Weisleder. Primer of Diagnostic Radiology, page 139-140