Descriptive anatomy based on three-dimensional imaging of the body, organs, and structures using a series of computer multiplane sections, displayed by transverse, coronal, and sagittal analyses. It is essential to accurate interpretation by the radiologist of such techniques as ultrasonic diagnosis, magnetic resonance imaging, and computed tomography. (From Lane & Sharfaei, Modern Sectional Anatomy, 1992, Preface)

Planes of Section Transverse Plane (axial) – run top to bottom, superior to inferior. Cranial to caudal

Planes of Section Coronal Follow front to back, anterior to posterior, or ventral to dorsal.

Planes of Section Sagittal One side of the body to the other, right to left, left to right, lateral to medial

Axial CT Axial MRI Axial PET

Coronal CTCoronal MR Coronal PET

Sagittal CTSagittal MR Sagittal PET

COMPARRISONS

THORACIC APERTURES Superior Aperture Thoracic Inlet Formed by first thoracic vert. First pair of ribs w/ costal cartilage Manubrium Functions: Passage way for nerves, vessels and viscera from the neck into the thoracic cavity

THORACIC APERTURES Inferior Aperture Thoracic Outlet Much larger 12th. thoracic vert. 12th. pair of ribs and costal margins Xiphoid Sternal junction

THORACIC APERTURES Inferior Aperture Thoracic Outlet

THORACIC APERTURES Superior Aperture Thoracic Inlet

BONY THORAX Protects the lungs and aids in respiration….

BONY THORAX Consists of; Vertebrae (12) Sternum (1) Ribs (12) pairs Costal cartilages

BONY THORAX Consists of; Vertebrae (12) Sternum (1) Ribs (12) pairs Costal cartilages

BONY THORAX Vertebrae (12) (7) Cervical (12) Thoracic (5) Lumbar (5) Sacral Vertebrae (3) (5) usually (4) Coccyx

BONY THORAX Cervical (7)

BONY THORAX Thoracic (12)

BONY THORAX Lumbar (5)

BONY THORAX Sacrum (5)

BONY THORAX Coccyx (3) (5)

STERNUM (3) Components: -Manubrium -Body -Xiphoid process -Sternoclavicular joints -Jugular notch - Sternal angle (T4-T5)

STERNUM

RIBS -Form the lateral borders of the thoracic cage - all (12) pairs articulate post. With T spine -First (7) pairs are TRUE -Lower (5) pairs FALSE

LUNGS - Organs of respiration - Large conical shaped -Apex - Diaphragm - Medial angle “Cardiophrenic sulcus” - Lateral angle “ Costophrenic sulcus” - Fissures -Cardiac notch -Hilum - Roots

LUNGS CT FACTS REGARDING THE THORASIC CAVITY -Contrast is normally used - If a nodule is seen, finer cuts may be indicated -Patient should hold breathe during exposure, however, not full inspiration -Usually start at level of shoulders and scan down -Patient must be centered to the middle of the table - Continuing scanning until you are out of both lungs, stop scanning at kidneys -Must include multiple windows; lung, mediastinum, bone, soft tissue and liver -evaluate all pathology - Carefully take your scout or Delta scan

THORACIC CONTENTS 1.Lungs (-) 2.Trachea (-) 3.Esophagus (+) 4.Thymus (+) 5.Aorta (ascending, descending, arch) (+) 6.IVC (+) 7.SVC (+) 8.Phrenic and Vagus nerves (+) 9.Heart (+) 10.Main bronchus (+) 11.Pulmonary artery (+) 12.Pulmonary veins (+) 13.Bronchial veins (+) 14.Lymph nodes (+)

LUNGS 1

LUNGS 3

SECTIONS 1.Pleural Space (sac) 2.Mediastinum (space between lungs) 3.Heart

SECTIONS Pleural Space

SECTIONS Heart

Components 1. Lungs (2) - Lt. and Rt. - Lt. is more concave (?) - Hilums (slits) (roots) - base, apex, costal surface and costophrenic angles - Lobes, Rt. (3) Lt. (2) - Fissures

Lobes of lungs

Fissures of lungs Separate lobes

COMPONENTS 2. Trachea - Passageway for air - 11cm long - splits into rt. and lt. stem bronchus between 2 nd and 3 rd rib CARINA -Rt. Bronchi’s is larger and more vertical than the lt. bronchi's. - Both divide into secondary and primary bronchioles

2. Trachea Bifurcation (Carina)

2. Trachea - After bronchioles an additional separation occurs where the alveoli exchange gas with capillaries….CO2 – O2

Capillary exchange -

COMPONENTS 3. Esophagus -Extends from pharynx to stomach. - Anterior to spine & posterior to trachea - Passes through the esophageal hiatus (opening)

COMPONENTS ESOPHAGUS

COMPONENTS ESOPHAGUS Axial CT

COMPONENTS ESOPHAGUS Sagittal MR

COMPONENTS 4. Thymus -(2) glands in the upper anterior chest wall - behind sternum - above the heart - large at birth, shrinks with age - STIMULATES GROWTH

COMPONENTS THYMUS GLAND Axial CT

COMPONENTS THYMUS GLAND PET

5 AORTA - Main trunk - Begins at lt. ventricle - passes behind sternum - behind sternum – ascending aorta - at sternal angle (left) - at thoracic vert. becomes descending aorta

AORTA

Multiple imaging

6 IVC - large trunk vein - enters from lower abdomen - enters right atrium

6 IVC CT/PET Fusion

7 SVC - Large trunk vein - receives branches from all of the body above the diaphragm except the lungs - Lies behind sternum

7 SVC AXIAL CT

8 Phrenic Nerve& Vagus Nerve Phrenic Vagus