ORIENTATION: VIEWING HEARTIN AXIAL CT AND MRI

Orientation of heartin axial CTand MRI

20 MINUTE ANATOMY VIDEOS

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RV

RALV

LA

4 CHAMBERED HEART

5 CHAMBERED HEART?

INVERTED Y SHAPE?

ORIENTATION: THORACIC CONTENTS ANTERIOR VIEW

R L

EsophagusTrachea

Subclavian V.

Left Int. Jugular V.

AORTA

PulmonaryTrunk

Structuresat Rootof Lung

diaphragm

R. Brachiocephalic V.

Sup. Vena Cava

POSTERIOR VIEWINCLUDINGTRACHEA,ESOPHAGUS

3) PulmonaryVeins

1) Arch of Aorta

2) PulmonaryArteries

2a) Trachea(bifurcation)

Esophagus,Thoracic duct

IVCdiaphragm

L R

Ordersimilarto root ofLung

HEART IS ON LEFT: REASON: ROTATED SO LEFT ATRIUM IS IN MIDLINE

Left Atrium - receives Pulmonary Veins symmetrically from both sides

LeftPulmonaryVeins

Right PulmonaryVeinsRV

LA

Right Ventricle -anterior

POSTERIOR VIEW: KNOW SEQUENCE

PulmonaryVeins 3) Pulmonary

Veins

1) Arch of Aorta

2) PulmonaryArteries

SVC

IVC

ANTERIOR VIEWAT TOP (SUPERIORLY) - VEIN IN FRONT OF ARTERIES

Arch of Aorta

Left Brachiocephalic Vein

SVC

Right Brachiocephalic Vein

Left Common Carotid ALeft Subclavian A

Brachiocephalic Trunk

ANTERIORVIEW

Reason: Allvenous blooddrains to RightAtrium

RV

Arch of AortaAscending

Aorta PulmonaryTrunk - fromConusArteriosus

ANTERIOR VIEWPULMONARY TRUNK - arises from Right Ventricle;

crosses anterior to Ascending Aorta; then branches

Conus Arteriosus

PULMONARYTRUNKON LEFTIN AXIALSECTIONS

RV

RA

LV

LA

CONUS ARTERIOSUSEXTENDS TOWARDLEFT; THENPULMONARY TRUNKBIFURCATES

YConus Arteriosus

AORTAARISES INMIDDLE OF HEART

AXIALSECTIONSLOOKLIKE5CHAMBEREDHEARTRV

RA

LV

LA

POSTERIOR VIEW: KNOW SEQUENCE

PulmonaryVeins 3) Pulmonary

Veins

1) Arch of Aorta

2) PulmonaryArteries

SVC

IVCL R

ORIENTATION: VIEWING HEARTIN AXIAL CT AND MRI

Orientation of heartin axial CTand MRI

RV

RALV

LA

RV

RA LA

LV

* - AORTA INCENTER OF HEART

CT, MRIVIEW HEARTFROM BELOW

R LIMAGE FLIPPEDVERTICALLY

Diaphragm Inferior vena cava

Esophagus

Azygous vein Thoracic (descending) aorta

Muscles of ventricles

R L

START ATDIAPHRAGM

Inferior vena cava

Interventricular septum

Azygous vein

Esophagus

Thoracic (descending) aorta

Left ventricle

Right ventricle

2 CHAMBERED HEART - ventricles onlyR L

Thoracic (descending) aortaEsophagus

Left ventricle

Right ventricle

4 CHAMBERED HEART!

Left atrium

Right atrium

R L

Left ventricle

Left pulmonary veinThoracic (descending) aorta

Azygous vein

Right atrium

Right ventricle

Right pulmonary vein Left atrioventricular

orifice

Right atrioventricular orifice

Interventricular septum

4 CHAMBERED HEART!R L

LALeft atrium

Left pulmonary veinRight pulmonary vein Azygous veinEsophagus

Thoracic (descending) aorta5 CHAMBERED HEART?

Left atrium

Right atrium

Left ventricle

Right ventricle* - AORTA - arisingfrom Vestibule

R L

Left main bronchus

Superior vena cava Ascending aorta

Azygous vein

RIGHT VENTRICLE EXTENDS TO LEFT

Right ventricle

RV

R L

Left pulmonary artery

Right pulmonary

artery

Carina at tracheal bifurcation Thoracic (descending) aorta

Ascending aorta

Superior vena cava

PULMONARY TRUNK BRANCHES

YY

Right ventricle to Pulmonary Trunk

R L

Arch of aortaSuperior vena cava

Trachea EsophagusR L

Superior vena cava

Spinal cord

Left subclavian artery

Scapula

Trachea

Esophagus

R L

Left brachiocephalic vein

TracheaEsophagus

Left common carotid

Right lung

Right brachiocephalic vein

Left subclavian artery

Brachiocephalic trunk

LEFT BRACHIOCEPHALIC VEIN CROSSES ANTERIORLY

R L

Summary - Orientation of heart in CT and MRI is complex; rarely appears to have 4 chambers.

1. Position and Orientation of heart - Heart is rotated and tilted so Right Ventricle is anterior and inferior; this makes functional sense; as a result, Left Atrium is located in midline and receives blood symmetrically from Pulmonary Veins (low pressure).

2. Sequence of Structures Inferior to Superior - Pulmonary Veins, Pulmonary artery, Arch of Aorta.

3. Pulmonary artery - arises from Conus arteriosus (Infundibulum) of Right Ventricle; ascends toward left and crosses anterior to Aorta; Pulmonary artery then bifurcates (appears Y shaped in axial CT and MRI).

4. Aorta - arises from Left Ventricle and first courses in middle of heart (Heart appears to have 5 chambers in axial CT and MRI at this level).

5. Order of Structures in Superior Mediastinum - Veins (R and L Brachiocephalic) are anterior to Arteries (Brachiocephalic, L Common Carotid, L Subclavian) arising from Arch of Aorta.

REMEMBER:

ANATOMICAL DETAILS ARE COMPLEX AND DIFFICULT TO LEARN

BUT

PATIENTS CAN DIE FROM 'MINOR DETAILS' OF ANATOMY.