Download Case study: Segementel approach to complex congenital cardiac

Case study:
Complex congenital
cardiac lesions…
Introduction
 MDCT and Cardiac MRI has stimulated the interest of
radiologists in the diagnosis of congenital heart disease and
encouraged the reappraisal of classifications and definitions
used by cardiologists and cardiac surgeons.
 The segmental analysis of congenital heart disease was
introduced 25 years ago and is now used worldwide.
 Radiographics April 2010
3 Step segmental review:
 Step 1: Visceroatrial situs is determined.
 Step 2: left- or rightward orientation of the ventricular loop is
evaluated, and the positions of the ventricles are identified on
the basis of their internal morphologic features.
 Step 3: The position of the great vessels is determined first,
and any abnormalities are noted.
1
1
1
2
1
1
3
1
(1,2,3)
(S,–,–), (I,–,–), (A,–,–).
Three step Review: Assessment
of Connecting Segments
 Step 4 Atrioventricular :The relationships between the atria
and ventricles.
 Step 5 Ventriculoarterial :The ventricles and great vessels.
 Step 6 Associated abnormalities : Cardiac chambers, septa,
outflow tract, and great vessels.
4
4
6
5
6
6
Step 1
Step 1: Determining the
Visceroatrial Situs
(S,–,–), (I,–,–), (A,–,–).
Step 1: Describe the position of the
heart in the thorax
 3 types of cardiac malposition: (determined by the orientation
of the cardiac base-apex axis)
 Dextrocardia
 Mesocardia
 Levocardia
(It is therefore important to detect any thoracic or pulmonary
anomalies that might lead to displacement of the heart)
Step 1: Situs
Liver
Stomach
Spleen
Step 1:Situs
 There are three types of situs: solitus (S,–,–), inversus (I,–,–),
and ambiguus (A,–,–).
 The type of situs is determined by the relationship between
the atria and the adjacent organs.
Step 1: Situs Solitus
 Right atrium and liver on the right side;
 Lhe left atrium, stomach, and spleen on the left side;
 Right-sided trilobed lung with an early origin of the upper lobe
bronchus from the right main stem bronchus;
 Left-sided bilobed lung with a more distal origin of the upper
lobe bronchus.
 The right pulmonary artery lies in front of the right bronchus,
and the left pulmonary artery crosses above the left
bronchus.
Situs Ambiguus
 When the situs is neither solitus nor inversus, it is referred to
as situs ambiguus or heterotaxy.
 Two subsets:
 right isomerism (asplenia)
 left isomerism (polysplenia)
Situs Ambiguus
 Left isomerism is usually indicated by bilateral bilobed lungs,
interruption of the IVC, multiple spleens, and pulmonary veins that
drain into both the right and the left atria
Step 1: Tracheo-Bronchial tree
Bilateral trilobed lungs
Step 1:Atrium
 Locate and identify the left and right atria.
 Anatomically, the atrial chamber differentiation is based on
the morphologic aspect of the atrial appendages.
 Right atrial appendage is broad and blunt (triangular)
 Left atrial appendage is narrow, pointed, and tubular
(fingerlike).
 Most of the time, the appendages are not reliably identifiable
at radiologic imaging, and the localization of noncardiac
organs is more helpful for determining the situs
Step 1:Atrium
 Supradiaphragmatic portion of the IVC also provides a
reliable landmark for locating the anatomic right atrium (rule
of venoatrial concordance)
Supradiaphragmatic
IVC
IVC
RA
RA
LA
RA
Step 1: Systemic venous
structures
 Main venous abnormalities that should be sought:
 (a) a left superior vena cava with or without an innominate vein
that drains either into the right atrium via the coronary sinus or
directly into the left atrium
 (b) a retroaortic position of the brachiocepahlic vein, behind the
ascending aorta
 (c) an interrupted inferior vena cava with azygos vein
continuation.
SVC 1
SVC 2
SVC 1
AZV
SVC 2
SVC 1
SVC 2
SVC 1
SVC 2
SVC 1
SVC 1
SVC 2
Step 1 summary
 Levocardia
 Situs ambiguous/inversus(spleen present)
 Bilateral Trilobed lungs
 Abnormal tracheo bronchial tree
 ? Common atrium
 TAPVC
 Bilateral SVC
 Bowel malrotation ? unsure
Step 2
Step 2: Determining the
Orientation of the Ventricular
Loop
(–,D,–) (–,L,–).
Step 2: Determining the
Orientation of the Ventricular
Loop
 The ventricular may tend rightward (dextro-loop) (–,D,–) or
leftward (levo-loop) (–,L,–).
Step 2: Identification of Right and
Left Ventricles
 Morphologic features:.
 Right ventricle: Coarse trabeculae, apical moderator band.
 Left ventricle: Thin and delicate trabeculae, septal surface is
smooth
Step 2: Identification of Right and
Left Ventricles
Loop rule:
 The identification may be based on the assumption that in
the presence of:
 a right-sided aortic valve, the right ventricle is located to the right
of the left ventricle (d-loop),
 a left-sided aortic valve, the right ventricle is located to the left of
the left ventricle (l-loop).
Step 2: Atrio ventricular valves
 In general, the mitral valve is associated with the
morphologic left ventricle, and the tricuspid valve is
associated with the morphologic right ventricle
 D-loop, the tricuspid valve is located to the right of the mitral
valve.
 L-loop, it is to the left of the mitral valve.
RV
?LV
Step 2 summary:
 Single right ventricle
 ?Hypoplastic left ventricle
 D-Loop
Step 3
Step 3: Determining the Origin
and Position of the Great
Vessels
(–,–,S); (–,–,I); (–,–,D-TGV)
(–,–,L-TGV); (–,–,D-MGV),
(–,–,L-MGV).
Step 3: Determining the Origin
and Position of the Great
Vessels
 6 variants:






Normal position (solitus) (–,–,S);
Inverted position (inversus) (–,–,I);
D-transposition (–,–,D-TGV)
L-transposition (–,–,L-TGV);
D-malposition (–,–,D-MGV)
L-malposition (–,–,L-MGV).
Step 3: Determining the Origin
and Position of the Great
Vessels
 Malposition: If the ventricular origin of an abnormal vessel
cannot be determined or if the great vessels arise from a
single ventricle
 Transposition usually applies when the aorta arises from the
right ventricle and the pulmonary artery arises from the left
ventricle
Step 3: Great vessels
 Two types of transposition exist: d-transposition (S,D,D-TGV)
and l-transposition (S,L,L-TGV).
 In L-transposition: aorta and pulmonary artery switch
positions
 In L-transposition: Great vessel and ventricular
swich(physiologically corrected transposition)
Normal relationship of the great
vessels
Aorta
PA
Step 3 summary
 D – MGV
 Aorta is positioned anterior and to the right of a hypoplastic
pulmonary artery
Three step Review:Assessment
of Connecting Segments
Assessment of Connecting
Segments:
Atrioventricular Connections
 5 types of atrioventricular connection:




2 ventricles present
Normal (RA – RV and LA – LV)
discordant (RA – LV and LA to RV)
Ambiguous(in cases of heterotaxy)
 Single Ventricle
 double inlet
 absent right or left connection
Assessment of Connecting
Segments: Ventriculoarterial
Connections
 4 types:
 Normal (the pulmonary artery arises from the right ventricle,
and the aorta arises from the left ventricle);
 Transposition of the great vessels (the pulmonary artery
arises from the left ventricle, and the aorta arises from the
right ventricle);
 Double outlet right ventricle (the great vessels arise from the
right ventricle);
 Double outlet left ventricle (the great vessels arise from the
left ventricle)
Assessment of Connecting
Segments: Associated
Malformations
 ASD, VSD, size of the ventricles, and the presence and
degree of any ventricular outflow tract stenosis.
 The aorta and pulmonary artery also should be carefully
examined for evidence of hypoplastic and stenotic lesions
(eg, aortic coarctation and hypoplasia of the aortic arch) +
PDA.
The Report
The report
 Images from thoracic CT angiography show situs ambiguous
(step 1), with the liver in the midline and towards the left, the
stomach and spleen on the right. There is a common atrium
with bilateral SVC’s and a TAPVC. Abnormal
tracheobronchial tree with bilateral right lungs. (step 2) Only
one ventricle is seen, and its trabecular inner surface is
characteristic of a right ventricle; this finding is suggestive of
left ventricular hypoplasia. A normal aorta is seen anterior
and to the right of a hypoplastic pulmonary artery (step 3).
The final report showed A,D, D-MGV, with an absent left
atrioventricular connection and with a double outlet right
ventricle.
Discussion
 Heterotaxy syndromes
 DORV (Great vessels originate from the RV,VSD, RARE)
 Single Ventricle( Most common LV,MPGV, RARE, High
morbidity)
 Hypoplastic left heart/Shone(PDA,ASD,dead in 1 week,large
RA, pulm oedema)