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Cardiac ImagingCardiac Position and Sinus

Cardiac Positions Levocardia: the heart is predominantly in the left chest,

the cardiac apex points leftward Dextrocardia: the heart is predominantly in the right

chest, and the cardiac apex points rightward Mesocardia: the heart is positioned in the midline, and the

cardiac apex points directly inferiorly Dextroposition (dextroversion): the cardia apex points

leftward, but the heart is located predominantly in the right chest (typically due to extrinsic forces)

Visceroatrial Situs “SITUS” refers to the pattern of anatomic arrangement Atrial situs is usually concordant with visceral situs; hence,

these two are described together Situs solitus

o The morphologic right atrium is to the right of the morphologic left atrium

o The gastric air bubbles is on the left side and the liver on the right

Situs inversuso The morphologic right atrium is to the left of the

morphologic left atriumo The gastric air bubbles is on the right side, and

the liver is on the left Situs ambiguous

This term is used when identification of visceroatrial situs is not possible due to paucity

of anatomic markers

Dextrocardia Sinus solitus

Dextrocardia Sinus inversus

Situs Ambiguous

Cardiac SizeCardio-Thoracic Ratio: divide the widest transverse diameter

of the heart by the widest transverse diameter of the thorax taken at the inner side of the rib cage

Chamber Enlargement

Right Atrial Enlargemento lateral bulging of the right

heart bordero elongation of the right

heart border (length of right heart border exceeds 50% of the mediastinal cardiovascular shadow)

Right Ventricular Enlargemento PA View : Rounding

and upliftment of cardiac apex

o Lateral View : Retrosternal fullness (contact of anterior cardiac border greater than 1/3 of the sternal length)

Left Atrial Enlargement

NOTES: In Dextrocardia, gastric bubbles is on the right side

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o PA view : Double density

o PA view : Enlargement of LA appendage

o PA view : Upliftment of left mainstem bronchus

o Lateral View : - Prominent posterosuperior cardiac border- Posterior displacement and upliftment of

left mainstem bronchus

Left Ventricular Enlargemento PA view : lateral

and downward displacement of the cardiac apex

o Lateral View : - Posterior

displacement

of the posterior inferior border of the heart

- Hoffman-Rigler Sign: measured 2 cm above the intersection of the diaphragm & IVC; (+) if posterior border extends more than 1.8 cm of IVC

Pulmonary Vascular Pattern

Comparison of Normal and Increased

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Lateral View

Comparison of Normal and Decreased

Lateral View

Venous Congestion

Increased Arterial Blood Flow

Kerley’s B lines

Perihalar Haziness

Peribronchial Cuffing

Redistribution Equalization

Redistribution Cephalization

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Interstitial Edema

The Great Arteries Aorta

o Normal

o Prominento Diminutive

Main pulmonary arteryo Normal

o Prominent

o concave

Conditions wherein pulmonary artery is concave: Transposition of great arteries TOF Pulmonary atresia

Congenital Heart Diseases Anatomic malformation of the

heart and or its vessels, which occurs during the intrauterine development

Radiologic Interpretation of congenital heart disease1. Cyanotic or acyanotic2. Vascularity: normal, increased, or decreased

Non-cyanotic ASD (RAE and RVE) VSD (both ventricles may

be enlarged and LA) PDA (LVE & LAE) AV canal defect

Increased Vascularity

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Ventricular Septal Defect Increased vascularity Normal or enlarged cardiac

size Chamber prominence:

o Either or both ventricles

o Left atrium Enlarged main and central

pulmonary arteries Normal or small aorta

VSD:

Patent Ductus Arteriosus Increased vascularity Normal or enlarged cardiac

size Chamber prominence: Left ventricle Left atrium Enlarged main and central

pulmonary arteries Prominent aortic knob

Atrial Septal Defect

Increased vascularity Cardiomegaly Chamber prominence:

o Right atriumo Right

ventricle Enlarged main and

central pulmonary arteries

Small aortic knob

Transposition of the Great Arteries (d-TGA) Increased vascularity Cardiomegaly Cardiac silhouette:

o “Egg on its side”o “Apple on a stem”

Narrow vascular pedicle

Patent Truncus Arteriosus Increased vascularity Pulmonary venous

congestion or edema is frequent in Type 1

Cardiomegaly Chamber prominence

o Either or both ventricles

o Left atrium Concave main pulmonary

artery segment (Prominent in Type 1)

Total Anomalous Pulmonary Venous Return Increased vascularity Cardiomegaly Chamber prominence

o Right atriumo Right ventricle

Enlarged systemic vein into which drainage occurs

Type 1 (Supracardiac)o left-sided vertical

vein connects pulmo venous confluence to the left innominate vein, right SVC or azygos vein

o “Snowman appearance” Type III (Infracardiac)

o Connection is below the diaphragm to the portal vein, ductus venousus or hepatic vein

o Pulmonary edemao Normal sized heart

Cyanotic dTGA TAPVR without

obstruction PTA Single ventricle DORV without pulmo

stenosis

Decreased Vascularity Normal Vascularity

Coarctation of the aorta Aortic stenosis Pulmonary stenosis

TOF Ebstein’s anomaly Severe pulmo stenosis Pulmo Atresia Tricuspid atresia with

pulmo stenosis DORV with pulmo

stenosis

Increased Venous Vascularity

Hypoplastic left heart Pulmonary vein stenosis TAPVR with obstruction

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o Prominence of the right atrium and less often the right ventricle

Tetralogy of Fallot Depressed vasularity Normal or enlarged

cardiac size Right ventricular

prominence Concave main

pulmonary artery segment

Prominent aorta Right aortic arch (in 20-

25%) Boot-shaped heart

Pulmonary Stenosis Normal to decreased

vascularity Normal or enlarged cardiac

size Right ventricular

prominence Post-stenotic dilatation of

the main pulmonary artery

Ebstein’s Anomaly Decreased vascularity Marked cardiomegaly Right atrial prominence “Balloon-“ or “box-

shaped”

Aortic Stenosis Normal vascularity Cardiomegaly Left ventricular prominence Dilated ascending aorta

Coarctation of the Aorta

Normal vascularity Cardiomegaly Left ventricular prominence “3” sign

Mitral Stenosis Normal to slightly enlarged heart Chamber prominence:

o Left atriumo Right ventricle

Equalization or cephalization of pulmonary blood flow

Prominent main pulmonary artery segment

Small aorta

Mitral Regurgitation Cardiomegaly Chamber prominence

o Left atrium (MR > MS)o Left ventricle

Pulmonary venous congestion (MR < MS)

Small aorta

Aortic Stenosis Normal-sized heart or mild

cardiomegaly Left ventricular

hypertrophy +/- pulmonary venous

hypertension Dilated ascending aorta

Aortic Regurgitation Cardiomegaly Left ventricular

enlargement Dilated ascending aorta

and aortic arch Normal pulmonay

vascularity