larynx imaging 1st part laryngeal anatomy ct mri dr ahmed esawy

Dr. Ahmed Esawy

MBBS M.Sc MD

ANATOMY OF THE LARYNX

• Position:

• The larynx projects forwards in the median part of the front of the neck. It extends from the root of the tongue to the trachea,

• lying opposite the third, fourth, fifth and sixth cervical vertebrae.

• Its upper end opens into the laryngopharynx by the laryngeal inlet, while its lower part is continuous with the trachea at the level of the sixth cervical vertebra.

• Lateral digital radiograph of neck. Superior and inferior limits of laryngeal examination Indicated by dashed lines. These limits include hyold bone (H) and epiglottis (arrows) superiorly and tracheal rings (arrowheads) inferionly. T - thyroid cartilage.

• hyperextended neck

• centralized

• 3MM

• IV contrast

Anatomic landmarks Hyiod bone

Laryngeal skeleton

the paired

1- arytenoid,

2- corniculate

3- cuneiform cartilage

the unpaired

4- thyroid

5- cricoid

6- epiglottic cartilages

supraglottic

7- Valleculae

8- Aryepiglottic fold

9- Glossoepiglottic fold

10- Laryngeal vestibule

11- False cord

12- Ventricle

13- Preepiglottic space

Anatomic landmarks

glottic

14-True cord

15-Thyroaryteniod muscle TAM

16-Anterior commissure

17-Posterior commissure

allthrough

18-Mucosal surface

19-Submucosal surface

20-Paraepiglottic space

21-Pyriform sinuses

22-Recurrent laryngeal nerve

23-Lymphatic drainage

Laryngeal skeleton

Consists of

the paired – arytenoid,

– corniculate

– cuneiform cartilage

the unpaired – thyroid

– cricoid

– epiglottic cartilages

Laryngeal

Cartilages

Anterior view

Posterior view

Epiglottis

Hyoid bone

Thyroid C.

Arytenoid C.

Cricoid C.

Laryngeal

Cartilages

Lateral view Sagittal

section

Epiglottis

Hyoid bone

Thyroid C.

Arytenoid C.

Cricoid C.

• Lateral radiograph of the neck showing the different structures of the larynx:

• a, vallecula;

• b, hyoid bone;

• c, epiglottis;

• d, pre-epiglottic space;

• e, ventricle (air-space between false and true cords);

• f, arytenoid;

• g, cricoid; and

• h, thyroid cartilage.

Osification of laryngeal

cartilage • Thyriod criciod most aryteniod hyaline

cartilage

• ossification begins 25 years

• Epiglottis ,apex aryteniod ,corniculate

,cuniform elastic cartilage

• little tendence to calcifiy

Hyoid bone:

• The hyoid bone is considered a

lingual bone

• The hyoid bone consists of a central

body and paired lateral greater and

lesser horns

• The line of fusion of the body and

greater horns of the hyoid bone

should not be mistaken for a fracture

• : The valleculae (v) are smaller.

• Normal lucency (white arrowhead) between the body and greater cornus of the hyoid bone is seen. Large arrow, omohyoid muscle; small arrow platysma muscle.

Thyriod cartilage

• Largest cartilage

• Bilateral cartilage plate (lamina)

• Superior cornua (horns)

• Inferior cornua (horna)

• Notch

• Laryngeal prominence

Variation in thyroid (large arrows) an cricoid

(small arrows) cartilage mineralization

Section of the Larynx

Epiglottis

Ventricular bands

Vocal folds

(Glottic area)

Supraglottic

area

Subglottic

area

Sagittal section

Ventricular bands

Ventricle

Vocal folds (Glottic

area)

Coronal section

• Coronal T1-weighted MR images of larynx. A, B: Successive dorsal images. large black arrow, cricoid cartilage; small black arrow, thyroid cartilage; small black arrowheads, laryngeal ventricle; small white arrowhead, arytenoid cartilage; small white arrow, aryepiglottic fold; P, pyriform sinus; PLS, paralaryngeal space; V, vestibule; S, strap muscles.

• Sagittal T1-weighted MR image of larynx.

• White arrow, epiglottis;

• white arrowhead, cricoid cartilage;

• black arrowhead, vallecula;

• H, hyoid bone;

• M, mylohyoid and geniohyoid muscles;

• PES, preepiglottic space.

Supraglottis boundaries

• tip of the epiglottis,

• inferiorly to the laryngeal ventricle

The supraglottis contents

• the epiglottis

• Glossoepiglottic folds

• valleculae

• aryepiglottic folds

• false vocal cords,

• arytenoid cartilage.

• Pyriform fossap

epiglottis

Thin leaf-shaped cartilage

Anterior border supraglottic larynx

Lingual and laryngeal surfaces

Free portion and base

Preepiglottic space

filled with loose areolar tissue

epiglottis

The supraglottic larynx

• A: The suprahyoid portion of the epiglottis (white arrow) is

seen posterior to the valleculae and anterior to the laryngeal

vestibule.

Just above the thyroid notch, the epiglottis (large arrow) has tapered and is not nearly as broad as its suprahyoid portion. A small amount of air (arrowhead) is seen within a minimally dilated left saccule of the laryngeal ventricle. S, infrahyoid strap muscles.

• Calcification in epiglottic cartilage, an unusual

finding in this elastic cartilage (arrow).

The supraglottic larynx

FVC

FALSE FOCAL CORDS

• Above and parallel to true vocal cord

• Attaches to thyriod cartilage and

aryteniod cartilage apex

• Fat density

• Laryngeal ventricle

• (invagination of mucosa between TVC and FVC)

• Laryngeal saccule appendix (2-4) mm

• Projects posteriorly from ventricle

The supraglottic larynx

FVC

The supraglottic larynx

FVC

• The false vocal cord (small arrows),

• level of the base (arrowhead) of the arytenoid cartilage

• thyroid notch (large arrow).

• C, common carotid artery; J, internal jugular vein; S, infrahyoid strap muscle; SCM, sternocleidomastoid muscle.

Ventricle

True cord=1

False cord=2

E=epiglottis

H=hyiod bone

ventricle (arrowhead)

Ventricle

True cord=1

False cord=2

T =thyriod cartilage

ventricle (arrowhead)

ventricle

• Arrows, laryngeal

ventricle; A, arytenoid

cartilages; CR, cricoid

cartilage.

cuneiform cartilage

• White arrowhead,

cuneiform

cartilage. Faintly

visible corniculate

cartilage (black

arrowhead) just

cephalad to

arytenoid cartilage.

Arrow, aryepiglottic

fold; P, pyriform

sinus.

Arytenoid cartilages

• Pyramidal shape

• Vocal process - anteriorly

• Apex

• corniculate cartilage in AE folds

• Muscular process laterally

• Articular base inferiorly

• concave

• site on superior border of posterior criciod ring

Cricoid & Arytenoids

Arytenoid cartilages

Glottis فتحة الحنجرة

• The glottis is made up of the

• true vocal cords

• anterior

• posterior commissures

True focal cord

• Composed of

• Vocal ligament

• Vocalis muscle

• Mucous memberane

• 9-10 mm thickness

• Muscular density

True focal cord

• Anterior comissure

• Immovable anterior junction

• Attches to inner perichondrium

of thyriod cartilage

• posterior comissure

• Midline mucosal noth between

aryteniods

Landmarks for true focal

cords • Anterior aryteniod cartilage

• Posterior ring criciod

• Anterior and posterior comissure

• True focal cord muscle density ,

false focal cord fat density

• Other land mark is change of air

cavity from multiple to single cavity

• True vocal cord should be

symmetrical in centralized patient

• True focal cord attach to base of

aryteniod cartilage

• False focal cord attach to apex of

aryteniod cartilage

Larynx true focal cords

•

• vocal process (small arrowhead)

• the arytenoid cartilage (A), cricoid cartilage (Cr), true vocal cord (small arrows).

• The thyroid lamina have fused anteriorly to form the laryngeal prominence (P).

• The soft tissues at the anterior commissure just posterior to the prominence should normally be less than 1 mm in thickness.

Larynx true focal cords

• Enhanced axial T1-weighted MR scan of the neck at the level of the glottis. The glottis is

made up of the true vocal cords (arrows) and the anterior (arrowhead) and posterior

commissures. Also, note the arytenoid cartilages (A), thyroid cartilage (T), and cricoid

cartilage (C).

subglottis

• Where is the subglottis?

• extends from the undersurface of

the true vocal cords through the

inferior surface of the cricoid

cartilage

Subglottic larynx

Cricoid cartilage

• Foundation of the larynx

• Complete signet ring

• broader posteriorly than anteriorly

• Articulates with inferior horn of

thyriod cartilage

• Articulates with base aryteniod

Cricoid & Arytenoids

Cricoid cartilage

Subglottic larynx

spaces

• Paraglottic

• preglottic

• The fat-containing preepiglottic space (PES) is seen anterior to the soft-tissue density epiglottis (small white arrowhead) and extends laterally into the paralaryngeal space (PLS) and then posteriorly into the aryepiglottic folds (arrows).

• P, pyriform sinus;

• black arrowhead, superior cornu of thyroid cartilage;

• large white arrowhead, normal spinal accessory lymph node;.

hypopharynx

• Posterior pharyngeal wall

• Pyriform sinuses

• Post criciod region

hypopharynx

• Two region of have important relation to larynx ‘ the pyriform sinuses and postcriciod region

pyriform sinus

• The indent the posterior wall of the

larynx.

• the anterior wall of the pyriform sinus

represent the anterior wall of the

paraglottic space

• the pyriform sinus makes up the

lateral aspect of the AEF

post cricoid

region

• The post cricoid region is that lower area

of the hypo pharynx that covers the

posterior aspect of the criciod cartilage