Ebook Atlas on X-ray and angiographic anatomy: Part 1

(BQ) Part 1 book “Atlas on X-ray and angiographic anatomy” has contents: Skull, spine, radiological procedures, ossifiatin centers, X- ray chest, abdominal radiograph, upper limb, lower limb.

Angiographic Anatomy

Angiographic Anatomy

JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTD

New Delhi • London • Philadelphia • Panama

Hariqbal Singh MD DMRDProfessor and HeadDepartment of Radiology Shrimati Kashibai Navale Medical College

Pune, Maharashtra, India

Parvez Sheik MBBS DMREConsultant RadiologyShrimati Kashibai Navale Medical College

Pune, Maharashtra, India

®

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of the contents of this work If not specifically stated, all figures and tables are courtesy of the authors Where appropriate, the readers should consult with a specialist or contact the manufacturer of the drug or device.

Atlas on X-ray and Angiographic Anatomy

Jaypee Brothers Medical Publishers (P) Ltd.

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Arvind Hariqbal and Naasiya Musthafa

offers framework to enter the infirmary,

clasp it firmly

it will help analyze the pathology rightly with foundation in place all is well the value of radiology cannot be measured

it can only be treasured.

Human anatomy has not transformed over the years but the advance in imaging has changed the perception

of structural details Thorough understanding of the normal anatomy is an essential prerequisite to precise diagnosis of pathology

Atlas on X-ray and Angiographic Anatomy is loaded with meticulously labeled illustrations This book is

steal a look into the anatomy in an easy and understandable manner

This atlas is meant for undergraduates, residents in orthopedics and radiology, orthopedic surgeons, radiologists, general practitioners and other specialists It is meant for medical colleges, institutional and departmental libraries and for stand-alone X-ray and orthopedic establishments They will find the book useful

Hariqbal Singh Parvez Sheik

We thank Professor MN Navale, Founder President, Sinhgad Technical Educational Society and Dr Arvind V Bhore, Dean, Shrimati Kashibai Navale Medical College, Pune, Maharashtra, India, for their kind acquiescence

in this endeavor

Our special thanks to the consultants Dr Sasane Amol, Roshan Lodha, Santosh Konde, Shishir Zargad, Yasmeen Khan, Shivrudra Shette, Anand Kamat, Varsha Rangankar, Prashant Naik, Abhijit Pawar, Aditi Dongre, Rajlaxmi Sharma, Manisha Hadgaonkar, Subodh Laul, Sumeet Patrikar, Ronaklaxmi, Shrikant Nagare and Vikash Ojha, who have helped in congregation of this imagery and for their indisputable help in assembly

of this educational entity

Our special appreciation to the technicians Mritunjoy Srivastava, Premswarup, Sudhir Mane, Sonawane Adinath, Deepak Shinde, Vinod Shinde, Yogesh Kulkarni, Pravin Adlinge, Parameshwar and Amit Nalawade, for their untiring help in retrieving the data

Our gratitude to Sachin Babar, Anna Bansode, Sunanda Jangalagi and Shankar Gopale, for their clerical help

We are grateful to God and mankind who have allowed us to have this wonderful experience

Last but not least, we would like to thank M/s Jaypee Brothers Medical Publishers (P) Ltd, New Delhi, India, who took keen interest in publishing the book

The term ‘Skull’ includes the mandible, likewise

the term ‘Cranium’ is the ‘Skull’ without the

mandible (Figs 1.1 and 1.2) The cranial cavity has

a roof (cranial vault) and floor (base of the skull)

The frontal bone occupies the upper third of

the anterior view of the skull; the rest is formed

by the maxillae and mandible The frontal bone

extends downwards to form the upper margins

of the orbits Medially the frontal bone articulates

with the frontal process of each maxilla Laterally

the frontal bone projects as the zygomatic process

to make the frontozygomatic suture with the

zygomatic bone at the lateral margin of orbit (Figs

1.3 to 1.6) The frontal bone articulates with the

parietal bones at the coronal sutures (which run

transversely)

The temporal bone consists of five parts–

Squamous, mastoid, petrous, tympanic and

styloid process The squamous portion forms

part of wall of temporal fossa and gives rise to

zygomatic process The mastoid portion contains

the mastoid antrum, in adults it elongates

into mastoid process The mastoid antrum

communicates with the remainder of mastoid air

cells and with the epitympanum via the aditus ad

antrum The petrous portion is wedge-shaped and

lies between the sphenoid bone anteriorly and

occipital bone posteriorly The tympanic portion

lies below the squamous part and in front of the

mastoid process The styloid portion forms the styloid process

The temporal fossa is the area bounded by the superior temporal line, zygomatic arch and the frontal process of the zygomatic bone The zygomatic arch is formed by the zygomatic process

of the temporal bone and the temporal process of the zygomatic bone The zygomatic process of the maxilla articulates with the zygomatic bone The zygomatic bone forms the bony prominence of the cheek (Figs 1.7 to 1.10)

The styloid process is a part of the temporal bone, from its tip the stylohyoid ligament passes

to the lesser horn of hyoid bone At the base of the skull medial to the styloid process the petrous bone is deeply hollowed out to form the jugular fossa with an opening called as jugular foramen through which the internal jugular vein passes Anterior to the jugular foramen the petrous part

of the temporal bone is perforated by the carotid canal, allows the internal carotid artery to pass through it (Fig 1.11) Between the basiocciput and the body of sphenoid bone lies the foramen lacerum, it allows the small emissary vein and meningeal branch of ascending pharyngeal artery

to pass through it The roof of the infratemporal fossa is pierced medially by the foramen ovale, through which passes the mandibular nerve, lesser petrosal nerve, accessory meningeal artery and emissary veins The base of the spine of sphenoid is perforated by the foramen spinosum

Skull

C H A P T E R

1

Figs 1.1A to D: CT scan multiplanar reconstruction images of skull: (A) Frontal view; (B) View from back;

(C) Lateral view; (D) View from below

which allows the middle meningeal vessels to

pass through it The stylomastoid foramen lies

behind the base of styloid process Medial to the

third molar tooth on either side is the greater

palatine, foramen between the horizontal plate

of palatine bone and the palatine process of the maxilla, the greater palatine vessels and nerves pass through it Behind the greater palatine, there are numerous small openings called the lesser palatine foramina in the pyramidal process of

Figs 1.2A and B: X-ray skull—AP view A

B

Figs 1.3A and B: X-ray skull—Lateral view A

B

Fig 1.4: X-ray skull—Mastoid view (Schuller’s view)

Fig 1.5: X-ray skull—Lateral view (close-up view to show the pituitary fossa)

palatine bone through which the lesser palatine

vessels and nerves pass

There are two parietal bones on either side of

skull They are seen better on lateral views of skull

and they articulate with the frontal bone anteriorly

at the coronal sutures Posteriorly, the parietal

bones articulate with occipital bone and temporal

bone mastoid process at lambdoid suture The bregma is the area in midline where the coronal sutures and the two parietal bones meet Behind the bregma, the parietal bones articulate in the midline sagittal suture This midline sagittal suture ends at the lambda in posteriorly The lambda is the area posterior where the sagittal suture ends

Fig 1.6: X-ray skull—PA view (Caldwell view for paranasal sinuses)

Fig 1.7: X-ray skull—Water’s view (for paranasal sinuses)

Fig 1.8: X-ray skull—Reverse Water’s view

Fig 1.9: X-ray skull—Towne’s view (30o fronto-occipital view)

Fig 1.10: X-ray skull—Submentovertical view

Fig 1.11: X-ray skull showing base of skull

in midline and the apex of occipital bone reaches

out to join it in midline The mastoid region of the

temporal bone articulates with the parietal and

occipital bones posteriorly, the mastoid process

projects down at the sides Inferiorly the parietal

bones articulate with the squamous portion of

temporal bone on either side

The occipital bone on its lower surface has

a ridge which is pointing towards the base of

the mastoid process; this is called the external

occipital protuberance The basiocciput extends

forward from the foramen magnum and fuses

with the basis phenoid The foramen magnum

is located in the basilar part of the occipital

bone (basiocciput) The pharyngeal tubercle is a

slight bony prominence in front of the foramen

magnum One-third of the foramen magnum lies

in front and two-thirds behind an imaginary line

joining the tips of the mastoid processes This is

contrary to the occipital condyles, where

two-thirds of the condyles lie in front of this imaginary

line

The internal surface of the base of skull is

divided into the anterior, middle and posterior

cranial fossa The orbital part of the frontal bone

forms a large part of anterior cranial fossa The

anterior cranial fossa extends up to the posterior

edge of the lesser wing of sphenoid The anterior

cranial fossa articulates with the cribriform plate

medially The crista galli is a sharp projection of

the cribriform plate

The sphenoid bone contributes to the

middle cranial fossa The small midline body of

sphenoid bone contains the sella turcica (means

‘Turkish saddle’), a small elevation in front of

sella turcica is called tuberculum sellae (Fig 1.5)

The tuberculum sellae has three small spikes,

the middle spike is called the middle clinoid

process, the two lateral spikes are called anterior

clinoid process At the posterior edge of the sella

turcica is an elevation called the dorsum sellae,

which has two lateral spikes called the posterior

clinoid process A fibrous portion of the dura

forms the roof of the sella turcica extending from

the tuberculum sellae to the dorsum sellae and is called the diaphragm sellae The diaphragm sellae has a central opening to allow the pituitary stalk and vessels to pass through it

The posterior cranial fossa extends from the petrous temporal bone anteriorly to the internal occipital protuberance in the midline The floor

is formed by the foramen magnum, basiocciput and posterior part of sphenoid bone The dorsum sellae slopes downwards in front of foramen magnum, this slope is called the clivus

The mandible or the jaw bone is a U–shaped, a horizontal central part with two lateral ramus on each side The posterior border of each ramus has

a condyle with a neck which articulates with the temporal bone forming the temporomandibular joint, while the anterior border of each ramus is sharp and is called the coronoid process (Figs 1.1

to 1.4)

The temporormandibular joint is a synovial joint between the head (condyle) of the mandible and mandibular fossa on the undersurface of the squamous part of the temporal bone The joint

is separated into the upper and lower cavities

by a fibrocartilaginous disc within it There

is no hyaline cartilage within the joint which makes it an atypical synovial joint The synovial membrane lines the inside of the capsule and the intracapsular posterior aspect of the neck

of the mandible The articular disc is attached around its periphery to the inside of the capsule and to the medial and lateral poles of the head

of the mandible The joint is more stable with the teeth in occlusion than when the jaw is open The movements at the temporomandibular joint are depression and elevation (opening and closing

of the jaws), side to side grinding movements, retraction and protaction movements (retrusion and protrusion)

THE NASAL CAVITY AND NASAL SEPTUM

The nasal cavity is pear-shaped, broader below and narrower at the top From its lateral walls the

conchae project into the nasal cavity There are

three conchae—Superior, middle and inferior

conchae The superior concha is small and is

found high in nasal cavity, its lower edge overlies

the superior meatus The sphenoethmoidal recess

lies above and behind the superior concha and

receives the ostia of sphenoidal sinus The middle

concha lies between the superior and inferior

concha The area in front of the middle meatus

is the atrium of nose Posteriorly, the middle

meatus is related to the splenopalatine foramen

The inferior concha lies below the middle

concha articulates anteriorly with the maxilla

and posteriorly with the palatine bone The nasal

septum (Fig 1.12) is normally in the midline, it

consists of bone (vomer) and cartilage It has a

lower free margin, superiorly it articulates with the

medial ends of frontal bone and also the frontal

process of maxilla The two maxillae on either side

meet in the midline and project forwards as the

anterior nasal spine at the lower margin of the

nasal aperture The vomer articulates with the

sphenoid body and forms the posterior border

of the septum The septal cartilage forms the

anterosuperior part of the septum The floor of the

nose is formed by the upper surface of the hard

palate The central part of the roof of nose is the

cribriform plate of the ethmoid

THE PARANASAL SINUSES

The paranasal sinuses all arise as evaginations

from the nasal fossa It comprises of frontal

sinuses, maxillary sinuses, sphenoid sinuses and

ethmoidal sinuses The nasal cavity contains

the superior meatus, middle meatus and the

inferior meatus The superior meatus drains the

posterior ethmoidal air cells and sphenoidal

sinuses The middle meatus drains the frontal

sinuses, maxillary sinuses and anterior ethmoidal

air cells The osteomeatal complex comprises of

the uncinate process, ethmoid infundibulum,

maxillary sinus ostium, middle turbinate, frontal

recess and ethmoid bulla The inferior meatus

has opening for the nasolacrimal duct (Figs 1.8 to

1.12)

The maxillary sinus lies in the body of maxilla, the sinus is triangular in shape, the apex in the zygomatic process of maxilla and the base towards the lateral wall of the nose The roof of the sinus is the floor of the orbit The floor of the sinus is formed by the alveolar part of maxilla The infratemporal fossa and pterygopalatine fossa lies behind the posterior wall of maxillary sinus The ostium of maxillary sinus is on the superomedial aspect of the sinus and opens into the middle meatus on the same side into the nasal cavity (Figs 1.2B and 1.3B)

The ethmoidal sinus lies between the nasal cavity and orbit The sinus is divided by multiple thin bony septa into the anterior and posterior group of ethmoidal air cells The lateral wall of the ethmoidal sinus forms a part of the medial wall of orbit; it is paper thin and is called the lamina papyracea The ostia of anterior ethmoidal air cells drain into the middle meatus The ostia

of posterior ethmoidal air cells drain into the superior meatus

The sphenoidal sinus occupies the body

of sphenoid bone A vertical septum divides the cavity into two unequal halves The roof of sphenoid sinus is formed by pituitary fossa and middle cranial fossa Laterally the sphenoid sinus

is related to the cavernous sinus and internal carotid artery Posteriorly, the sphenoid sinus is related to the posterior cranial fossa and pons The ostium of sphenoidal sinus is in the anterior wall

of the sinus and opens into the superior meatus or into the sphenoethmoidal recess

The frontal sinuses are formed within the frontal bone on either side near midline Its floor forms the roof of orbit medially Posteriorly the frontal sinus is related to anterior cranial fossa The ostium of frontal sinus is at its lower medial edge and drains into the middle meatus in nasal cavity or in some cases into the anterior ethmoidal air cells

THE ORBIT

The bony orbit is a cavity, shaped like a pyramid with its apex posteriorly and the base forming

Fig 1.12: X-ray skull—Lateral view (for nasal bones)

Fig 1.13: X-ray skull—AP view in a 2-year-old child

the orbital margins anteriorly The orbital roof is

formed by the frontal bone, which separates the

orbit from the anterior cranial fossa The orbital

floor is formed by the orbital plate of the maxilla,

portions of the palatine bone and the zygoma (Figs 1.10, 1.13 and 1.14) The maxillary portion

of orbital floor is usually involved in blow out fractures The medial orbital wall is the thinnest

Fig 1.14: X-ray skull—Lateral view in a 2-year-old child

of all the orbital walls and comprises of frontal

process of the maxilla, lacrimal bone, lamina

papyracea and bony sphenoid The lateral wall of

orbit is formed by the zygoma and greater wing of

sphenoid The superior orbital fissure is a space

between the greater and lesser wings of sphenoid

The inferior orbital fissure is formed by the

maxilla, the palatine bone and the greater wing

of sphenoid The optic canal lies within the lesser

wing of sphenoid, the optic nerve and ophthalmic

artery encased in the dural sheath pass through it

Structures passing through the superior orbital fissure: Superior ophthalmic vein, the rectus muscles (superior, inferior, medial and lateral), lacrimal nerve, frontal nerve, trochlear nerve, oculomotor nerve, abducent nerve, nasociliary nerve

Structures passing through the inferior orbital fissure: Infraorbital artery, inferior ophthalmic vein, zygomatic nerve, infraorbital nerve

Structures passing through the optic canal: Optic nerve, ophthalmic artery

C H A P T E R

2

Two common radiographic views taken for the

spine are the AP view and the lateral view Most

disease process involving the vertebral body or the

posterior elements can be noted on these views,

however, special views like posterior oblique view

may be necessary in some cases

The spine is made up of five groups of

vertebrae The portion of spine around the neck

region is cervical spine It is formed by first seven

vertebrae which are referred as C1 to C7, followed

by 12 thoracic vertebrae referred as T1 to T12 and

subsequently five lumbar vertebrae L1 to L5 in

the low back area The sacrum is a big triangular

bone at the base, its broad upper part joins the

L5 vertebra and its narrow lower part joins the

coccyx or tail bone

CERVICAL SPINE

It starts with first cervical vertebra (C1) attached

to the bottom of the skull, the basiocciput Atlas is

the name given to C1 vertebra as it supports and

balances the weight of the skull It has practically

no body or spinous process, it appears as two

thickened bony arches which join anteriorly as

anterior tubercle and posteriorly as posterior

tubercle These two thickened bony arches join to

form a large hole with two transverse processes

On its upper surface, the atlas has two facets

that unite with the occipital condyles of the skull Structure of atlas is unique and has a large opening which accommodates spinal cord (Figs 2.1 and 2.2)

The second vertebra is the “axis”, it lies directly beneath the atlas vertebra It bears large bony tooth-like protrusion on its summit, the odontoid process or the dens This process projects upward and lies in the ring of the atlas The joints of the axis give the neck its ability to turn from side to side, i.e left and right, as the head is turned, the atlas pivots around the odontoid process The odontoid process arises from anterior part of C2 vertebrae and articulates with the C1 vertebrae above to form the atlanto-occipital joint (Figs 2.2, 2.3 and 2.10) Special views may be taken on plain radiographs to demonstrate the atlantoaxial joint and atlanto-occipital joint

The transverse processes of the cervical vertebrae have large transverse foramina to allow the vertebral arteries into the cranium The spinous processes of the second to fifth cervical vertebrae are forked providing attachments for various muscles

C3-C6 vertebrae have a typical structure C7 vertebra is called vertebra prominens because

of a long prominent thick nearly horizontal not bifurcated spinous process which is palpable from the skin (Figs 2.4 to 2.9)

Figs 2.1A to D: (A) Cervical spine MRI sagittal section T2WI; (B) Multiplanar reconstructed CT scan images of cervical spine

posterior view; (C) View from above; (D) Lateral view

There are eight cervical spinal nerves and

the neural foramina of cervical spine allow the

cervical spinal nerves to exit out of the spinal

canal

DORSOLUMBAR SPINE

It consists of twelve vertebrae in the chest area,

the first thoracic vertebra articulates with the

C7 vertebra above and the last thoracic vertebra

articulates with the first lumbar vertebra below

The thoracic vertebrae are larger in size than

those in the cervical region They have long,

pointed spinous processes that slope downward,

and have facets on the sides of their bodies that

join with ribs From the third thoracic vertebra

onwards to the last thoracic vertebra, the bodies

of these bones increases in size gradually (Figs

2.11 to 2.13) This reflects the stress placed on

them by the increasing amounts of body weight

they bear There are five “lumbar vertebrae” in the

lower back They have larger and stronger bodies

to provide support The transverse processes of these vertebrae project backward at sharp angles, while their short, thick spinous processes are directed nearly horizontally

LUMBOSACRAL SPINE

The 5 lumbar vertebrae in the lower back are prone to injuries On AP views the pedicles and transverse process need to be examined to rule out any fracture On lateral views, the curvature

of lumbar spine needs to be examined, note any slipping of one lumbar vertebra over the other The intervertebral disc spaces should be equal

in size (Figs 2.14 to 2.16) Additional views like posterior oblique view may be necessary in some cases The sacrum is a large triangular bone on

AP view at the base of the lower spine Its broad upper part joins the lowest lumbar vertebrae and its narrow lower part joins the coccyx or “tail

B

Figs 2.2A and B: X-ray cervical spine—Lateral view

Fig 2.3: X-ray cervical spine—Lateral view for C1-C2 vertebrae

bone” (Fig 2.17) The sides are connected to the

iliac bones (the largest bones forming the pelvis)

The sacrum is a strong bone and rarely fractures

The five vertebrae that make up the sacrum are

separate in early life, but gradually become fused

between the eighteenth and thirtieth years

The spinous processes of these fused bones are

represented by a ridge of tubercles The weight

of the body is transmitted to the legs through the

pelvic girdle at these joints

COCCYX

It is the lowest part of the vertebral column and

is attached by ligaments to the margins of the

sacral hiatus It is better viewed on lateral views of

sacrum with coccyx (Fig 2.17) Sometimes bowel

gases may obscure a clear picture of coccyx When

a person is sitting, pressure is exerted on the

coccyx, and it moves forward, acting like a shock

absorber Sitting down with force may cause the

coccyx to be fractured or dislocated

GENERAL FEATURES OF SPINE

The vertebral body is shaped like an hourglass,

thinner in the center with thicker ends Outer

cortical bone extends above and below the

superior and inferior ends of the vertebrae to form rims The superior and inferior endplates are contained within these rims of bone The bodies of adjacent vertebrae are joined on the front surfaces by “anterior ligaments” and on the back by “posterior ligaments” A longitudinal row

of the bodies supports the weight of the head and trunk

Intervertebral discs are found between each vertebra They are better viewed on lateral radio-graphs Intervertebral discs make up about one-third of the length of the spine and constitute the largest organ in the body without its own blood supply The discs receive their blood supply through movement The discs are flat, round structures about a quarter to three quarters of an inch thick with tough outer rings of tissue called the annulus fibrosis that contain a soft, white, jelly-like center called the nucleus pulposus Flat, circular plates of cartilage connect to the vertebrae above and below each disc Intervertebral discs separate the vertebrae, and act as shock absorbers for the spine

Projecting from the back of each body of the vertebra are two short rounded stalks called

“pedicles” They form the sides of the “vertebral foramen” They can be viewed on both AP and

Figs 2.4A and B: X-ray cervical spine—AP view A

B

Fig 2.5: X-ray cervicothoracic junction—AP view

Fig 2.6: X-ray cervical spine swimmer’s view for cervicothoracic junction

lateral radiographs Pedicles extend posteriorly

from the lateral margin of the dorsal surface of the

vertebral body

The laminae are two flattened plates of bone

extending medially from the pedicles to form

the posterior wall of the vertebral foramen These laminae are better seen on lateral views

on radiographs They fuse posteriorly in the midline to become spinous process The pars interarticularis is a special region of the lamina

Fig 2.7: X-ray cervical spine right posterior oblique for intervertebral foramina

Fig 2.8: X-ray cervical spine—Lateral view in flexion

Fig 2.9: X-ray cervical spine—Lateral view in extension

Fig 2.10: X-ray cervical spine open mouth view for atlantoaxial junction

between the superior and inferior articular

processes A fracture or congenital anomaly of the

pars may result in a spondylolisthesis

The pedicles, laminae, and spinous process

together complete a bony vertebral arch around

the vertebral opening, through which the spinal

cord passes Between the pedicles and laminae

of a typical vertebra is a “transverse process” that projects laterally and toward the back Various ligaments and muscles are attached

to the transverse process Projecting upward and downward from each vertebral arch are

“superior” and “inferior” arti culating processes These processes bear cartilage-covered facets by

Figs 2.11A to C: Multiplanar reconstructed CT scan images of dorsolumbar spine: (A) Posterior view;

(B) Anterior view; (C) Lateral view

which each vertebra is joined to the one above

and the one below it These facet joints facilitate

smooth gliding movement of one vertebra on

another to produce twisting motions and rotation

of the spine Facet joints are also called as

zygapophyseal joints

On the surfaces of the vertebral pedicles are

notches that align to create openings, called

“intervertebral foramina” These openings

provide passageways for spinal nerves that exit

out of the spinal cord

SPINAL CANAL AND SPINAL CORD

The spinal canal is bounded anteriorly by

the vertebral bodies, the intervertebral discs,

posterior longitudinal ligament Posteriorly it is related to the lamina and ligamentum flavum Laterally on either side, it is related to the pedicles The intervertebral foramina contain the spinal nerves, posterior root ganglia, spinal arteries and veins The vertebral canal contains the spinal cord The spinal canal encases the spinal cord The bones and ligaments of the spinal column are aligned in such a manner to create a column that provides protection and support for the spinal cord The outermost layer that surrounds the spinal cord is the dura mater, which is a tough membrane that encloses the spinal cord and prevents cerebrospinal fluid from leaking out The space between the dura and the spinal canal is called the epidural space This

Figs 2.12A and B: X-ray dorsolumbar spine—Lateral view A

B

Figs 2.13A and B: X-ray dorsolumbar spine—AP view

A

B

space is filled with tissue, vessels and large veins

Up to the third month of fetal life, the spinal cord

is about the same length as the canal The growth

of the canal outpaces that of the cord from the

3rd month onwards In an adult the lower end of

the spinal cord usually ends at approximately the

first lumbar vertebra, where it divides into many

individual nerve roots that travel to the lower body and legs This collection of group of nerve roots is called the “cauda equina” MRI spine

is the modality of choice to examine the spinal canal and spinal cord CT spine is preferred in cases of acute trauma and those who cannot undergo MRI studies

Figs 2.14A to D: Multiplanar reconstruction CT scan images of lumbosacral spine: (A) Posterior view; (B) Lateral view; (C)

Lateral view showing the intervertebral neural foramina; (D) Oblique view

C

D

SOME DIFFERENTIATING FEATURES

BETWEEN CERVICAL, THORACIC AND

LUMBAR VERTEBRAE

C3-C6 vertebrae have atypical features The body

of these four vertebrae is small and broader from

side-to-side than from front-to-back The pedicles

are directed laterally and backward The laminae

are narrow, and thinner above than below The

vertebral foramen is large and has triangular

shape The spinous process is short and bifid

Superior articular facets face backward, upward,

and slightly medially and inferior face forward,

downward, and slightly laterally

The foramen transversarium is an opening

in the transverse processes of the seven cervical

verte brae It gives passage to the vertebral artery,

vein and plexus of sympathetic nerves in each of

the vertebrae except the seventh, which lacks the

artery C7 has enlarged spinous process called the

vertebral prominence

The thoracic vertebrae have costal facets for ribs

on either sides of the vertebral body They increase

in size gradually from T3 vertebra downwards The lumbar vertebrae have neither a foramen

in transverse process nor costal facets; they are larger than the dorsal and cervical vertebrae in size

RADIOLOGICAL IMPORTANCE OF VERTEBRAL COLUMN IN SPINAL INJURIES

The vertebral column can be sub divided as anterior column, middle column and the posterior column Injuries involving the middle and posterior columns result in unstable injuries

• Anterior column is formed by anterior longi­tudinal ligament, anterior annulus fibrosus and anterior part of vertebral body

• Middle column is formed by posterior longi­tudinal ligament, posterior annulus fibrosus and posterior part of vertebral body

Figs 2.15A and B: Lumbosacral spine X-ray—AP view A

B

Figs 2.16A and B: Lumbosacral spine X-ray—Lateral view A

B

Fig 2.17: Sacrum and coccyx X-ray—Lateral view

• Posterior column includes posterior elements

and ligaments

RADIOLOGICAL IMPORTANCE OF

CRANIOVERTEBRAL JUNC TION

Chamberlain line is the line between posterior

part of hard palate and posterior margin of

foramen magnum Normally the tip of odontoid process lies at or below this line Basilar line is the line along the clivus and it usually falls tangent to the posterior aspect of the tip of odontoid

Craniovertebral angle (Clivus-canal angle) is angle between basilar line and a line along posterior aspect of odontoid process If this angle is < 150º, cord compression can occur on the ventral aspect