先天性心脏病的节段分析法

It is important to detect any thoracic or pulmonary anomalies that might lead to displacement of the heart.
Cardiac dextroposition due to right lung hypoplasia after a right diaphragmatic hernia repair
➢ Assessment of Cardiac Anatomy ➢ Assessment of Connecting Segments ➢ Assessment of Associated Malformations
Step 1: Determining the Visceroatrial Situs
right main stem bronchus; the right pulmonary artery lies in front of the right bronchus (eparterial bronchial position); ➢ a left-sided bilobed lung with a more distal origin of the upper lobe bronchus; the left pulmonary artery crosses above the left bronchus (hyparterial bronchial position).
Segmental Approach to Imaging of Congenital Heart Disease
杜倩妮 20பைடு நூலகம்9.09
The segmental approach, which is widely used in the imaging workup of congenital heart disease, consists of a three-step evaluation of the cardiac anatomy.
➢ Step 1: Determining the Visceroatrial Situs ➢ Step 2: Determining the Orientation of the Ventricular Loop ➢ Step 3: Determining the Origin and Position of the Great Vessels
➢ At the abdominal level, the positions of the liver, stomach, and spleen are of paramount importance.
➢ The supradiaphragmatic portion of the inferior vena cava (IVC) also provides a reliable landmark for locating the anatomic right atrium (because of the rule of venoatrial concordance).
Three types of situs:
solitus
(S,–,–)
inversus (I,–,–)
ambiguus (A,–,–)
The type of situs is determined by the relationship between
the atria and the adjacent organs
Situs inversus, the anatomic configuration is an exact inversion of that in situs solitus.
situs solitus (a) and situs inversus (b)
Situs Ambiguus
➢ Cardiac anomalies ➢ Venoatrial connections anomalies ➢ Extracardiac anomalies (eg, splenic abnormalities, biliary atresia, and intestinal
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)
With regard to the global location of the heart within the chest cavity
Dextroposition:a location predominantly in the right chest Mesoposition: a midline location of the heart Levoposition: a location mainly in the left chest
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.
right isomerism (asplenia) (a) and left isomerism (polysplenia) (b)
In general, cardiac and situs anomalies are less frequently found with a concordant position of the cardiac apex, stomach, and aortic arch and occur more frequently with a discordant position of one or more of these landmarks.
Isolated dextrocardia has been used to distinguish a situs solitus with a d-loop
from true dextrocardia with an l-loop
Isolated levocardia as a result of congenital cardiac malposition occurs only with
In all three variants, the cardiac base-apex axis may be oriented normally (toward the left chest)
With regard to the orientation of the cardiac base-apex axis
In the left ventricle, the trabeculae are thin and delicate, and the septal surface is smooth. The two papillary muscles of the left ventricle are attached only to the free wall.
malrotation)
Right isomerism: bilateral trilobed lungs, a large symmetric liver, absence of the spleen, and total anomaly of the pulmonary venous return
(–,D,–) (–,L,–)
a d-loop (left) and an l-loop (right)
D-loop: with resultant positioning of the bulbus cordis to the right of the left ventricle, the heart rotates into the left thorax L-loop: the right ventricle is positioned to the left of the left ventricle, and rotation of the heart into the right thorax
Polysplenia
Step 2: Determining the Orientation of the Ventricular Loop
Three types of situs: rightward (dextro-loop, d-loop) leftward (levo-loop, l-loop)
In the right ventricle, the trabeculae are coarse, and the presence of an apical moderator band is characteristic. The papillary muscles of the right ventricle are attached to both the interventricular septum and the free wall.
➢ At the thoracic level, the bronchial (pulmonary) anatomy, especially the relationship between the main right and left bronchi and the pulmonary arteries, is a reliable indicator of the atrial arrangement.
Situs Solitus and Situs Inversus
Situs solitus is the normal anatomic configuration, with
➢ the right atrium and liver on the right side; ➢ the left atrium, stomach, and spleen on the left side; ➢ a right-sided trilobed lung with an early origin of the upper lobe bronchus from the
situs inversus and situs ambiguus
The features that help differentiate between the right and left ventricles are the texture and distribution of internal trabeculae.
Three types of cardiac malposition: Dextrocardia: a heart located in the right thorax, with the base-apex axis tilted toward the right Mesocardia Levocardia
Left isomerism:bilateral bilobed lungs,interruption of the IVC, multiple spleens, and pulmonary veins that drain into both the right and the left atria