M-1 RADIOLOGY Head and Neck

OBJECTIVES Skull, Sinus and Orbit anatomy Vascular anatomy Neck anatomy Clinical cases Here are our objectives.

SKULL ANATOMY To start with skull anatomy.

SINUSES Nasal Septum Frontal Sinus Maxillary Sinus Ethmoid Sinus PA view Nasal Septum Frontal Sinus Maxillary Sinus Ethmoid Sinus Inferior Turbinate Superior orbital fissure 2 6 4 3 1 Comparing the skull x-ray and a specimen structures deep to the bony surface are visible. 5

1- Superior orbital fissure 2- Inferior orbital foramen 3- Mental foramen 1 2 1 Here we have made a 3-D model from CT sections and present it as compared with specimen. Note the corresponding foramen labeled. 2 3 Fissures and foramen have nerves that show on lab practicals. 3

OPTIC CANAL Here on this oblique view the optic canal is seen along the medial border of the superior orbital fissure.

AP WATERS VIEW SINUSES 1 2 3 4 1. Frontal sinus 2. Zygomatic-Frontal Suture 3. Maxillary Sinus 4. Inferior orbital margin 1 2 3 4 This view is angled to project the maxillary sinuses free of the petrous ridge.

Note the opacified right maxillary sinus with fluid layering dependently indicating sinusitis

WHAT RECTUS MUSCLE CAN BE INJURED BY EYE TRAUMA? Superior Inferior Medial Lateral Inferior

Arrow points to bone fragment ORBITAL FLOOR FRACTURE Arrow points to bone fragment displaced into orbit. The inferior rectus muscle can become entrapped in fracture

CT FACIAL CORONAL SCAN Here the trauma shows the inferiorly displaced floor of the orbit which can entrap the inferior rectus muscle. CT scans redemonstrate fracture and edema at site.

1. Frontal Sinus 2. Maxillary Sinus 3. Ethmoid Sinus 4. Sphenoid Sinus The lateral x-ray and the specimen compared. LATERAL SINUS & SKULL

Middle meningeal artery The middle meningeal artery, a branch of the maxillary artery runs in a groove along the innner table of the skull.A fracture through the skull can injure the middle meningeal artery and the bleeding here can cause an epidural hematoma causing mass effect on the subjacent brain.

Magnified image

Cause: Laceration of the meningeal artery adjacent to inner table. EPIDURAL HEMATOMA FRACTURE The fracture extends through the skull at the site of the middle meningeal artery.The arterial blood disects the dura (periosteum) from the inner table due to the higher arterial pressure and creates a convex mass. Cause: Laceration of the meningeal artery adjacent to inner table. 15

Normal skull The pituitary gland is seen in the sella inferior to the arrow. The pituitary stalk connects the brain to the pituitary gland. The optic chiasm is above the gland. Sella

CAROTID CANAL JUGULAR FORAMEN Here on the CT section the carotid and jugular canals are seen. CT SKULL BASE

PINNA MANDIBULAR CONDYLE A more cephalad section shows condyles and mastoid air cells. The pinna is seen on the left. Mastoid air cells show small bony septa and air density indicating normal ventilation. MASTOID AIR CELLS CT SKULL BASE

SKULL BASE FRACTURE On the left the fracture is seen and the mastoid air cells are opacified with the bleeding and edema from the fracture Skull base fracture can lead to cerebral spinal fluid leak and risk of meningitis.The purple ecchymosis behind the ear is called Battle sign described as a clinical finding with basilar fractures here. The blood from the fracture tracks superficially to the skin over the mastoid air cells.

“RACCOON EYES” Periorbital ecchymosis is a sign of a basal skull fracture. Blood tracks along the periosteum and can collect in soft tissues of the orbital lid. Blood may track anteriorly from other skull base fractures and pool in soft tissues of the orbit from a basilar skull fracture and show Raccoon eyes.

ZYGOMATIC ARCH EXTERNAL AUDITORY CANAL Further cephalad CT SKULL BASE

FORAMEN OVALE PETROUS CAROTID CANAL FORAMEN SPINOSUM The foramen ovale and spinosum, petrous portion of carotid artery and the clivus. CLIVUS CT SKULL BASE

INTERNAL AUDITORY CANAL CAROTID CANAL OSSICLES The carotid canal continues through the skull base to lie adjacent to the sella. The 7th and 8th cranial nerves enter the IAC. The skull specimen is viewed from the top looking inside. IAC INTERNAL AUDITORY CANAL CT SKULL BASE

Acoustic neuroma is a slow growing tumor that develops on the 8th cranial nerve. Symptoms include unilateral loss of hearing, Tinnitus-ringing in ears. dizziness and vertigo. Here the MR scan shows a mass at the internal auditory canal on the right compared with the left side.A tumor of the 8th cranial nerve called an Acoustic Neuroma or Schwannoma.

SINUS AND ORBIT ANATOMY To now look in more detail at sinus and orbit anatomy with CT.

SINUSES PA view Frontal Sinus Maxillary Sinus Ethmoid Sinus 1 3 2

SINUSES AP WATERS VIEW Frontal sinus 2. Zygomatic-Frontal Suture 3. Maxillary sinus 4. Inferior orbital margin 1 2 3 4 This view is angled to project the maxillary sinuses free of the petrous ridge. The Frontal and Maxillary sinuses are seen on the Waters view. The Ethmoid and Sphenoid sinuses are obscurred by bone This view is angled to project the maxillary sinuses free of the petrous ridge.

LATERAL SINUS & SKULL 1. Frontal Sinus 2. Maxillary Sinus 3. Ethmoid Sinus 4. Sphenoid Sinus 5. Sella Turcica 1 3 5 4 The lateral x-ray and the specimen compared. 2 LATERAL SINUS & SKULL

Scans start superiorly and are shown going inferiorly CT- SINUS AXIAL VIEW 1 1. Frontal Sinus We have a series of sections starting cephalad and working caudad. The skull xray and line shows the level of the section. Scans start superiorly and are shown going inferiorly

CT SINUS AXIAL SCAN normal The opacified sinus can cause bone destruction with the chronic bacterial/fungal infection. This can lead to meningitis and abscess formation. Note the destroyed posterior wall of the left frontal sinus due to bacterial invasion.

CT- SINUS 1. Ethmoid sinus 2. Sphenoid sinus 3. Carotid canal AXIAL VIEW 1 As we move inferiorly, we now see we are at the level of the orbits 1. Ethmoid sinus 2. Sphenoid sinus 3. Carotid canal 2 3

CT- SINUS Maxillary sinus Med. & Lat. Pterygoid plate Nasopharynx AXIAL VIEW 1 Maxillary sinus Med. & Lat. Pterygoid plate Nasopharynx Nasal septum Inferior turbinate 4 5 Below the orbits we are now at the level of the maxilla on the next two sections. 2 3

Coronal sections extending from anterior to posterior CT- SINUS Coronal sections extending from anterior to posterior 2 Fronto-nasal suture Frontal sinus Nasal bones 1 On these sections we are creating coronal images viewed as though the patient is looking at us. Most anteriorly, we can see the nasal bones 3

CT- SINUS 1. Ethmoid sinus 2. Maxillary sinus 3. Middle turbinate CORONAL VIEW 1 3 1. Ethmoid sinus 2. Maxillary sinus 3. Middle turbinate More posteriorly we are now behind the globes. Note the thin cribiform plate separarating the ethmoid roof from the anterior cranial fossa

CT- SINUS CORONAL VIEW Maxillary sinus This image of the maxillary sinuses in a different patient shows the ostea of the sinuses draining. Maxillary sinus

CT- SINUS Sphenoid sinus Hard palette Anterior clinoid CORONAL VIEW 3 1 Sphenoid sinus Hard palette Anterior clinoid Now we can see the sphenoid sinuses and the anterior clinoid processes. 2

CT ORBIT Retro orbital fat Medial rectus Lens Lateral rectus AXIAL SCAN Retro orbital fat Medial rectus Lens Lateral rectus Optic nerve 2 4 1 3 5 Here axial sections through the orbits are viewed at a soft tissue level to see the muscles, nerve and orbital fat. Note the bony detail is not as well seen as on the sinus/bone images.

MR SCAN AXIAL SCAN CORONAL SCAN Optic nerves Chiasm Further cephalad shows the two optic nerves extend through the optic canal and converge to form the chiasm. The coronal scan shows the CHIASM with the pituitary stalk and gland inferiorly. MR SCAN 38

In Biblical liturature who showed a knowledge of cranial nerve anatomy? Moses Noah David Goliath David

Normal Sella Mass The mass impinges on the optic chiasm to create the visual disturbance. Pituitary tumors can secrete growth hormone and lead to gigantism. Goliath, the giant of Biblical history may have been one. His pituitary tumor pressure on the chiasm caused a visual field defect “tunnel vision” –bitemporal hemianopsia which allowed his foe- David to get close enough by staying in the peripheral visual where he could not be seen. Compare the normal with the enlarged pituitary adenoma. The mass impinges on the optic chiasm to create the visual disturbance.

NECK ANATOMY To now move to more soft tissue anatomy of the oral cavity and neck

LATERAL NECK Hard palate Soft palate Nasopharynx Oropharynx Epiglottis 3 LATERAL NECK Hard palate Soft palate Nasopharynx Oropharynx Epiglottis 1 2 4 5 On this lateral view the air outlines soft tissue structures. A mid line MR is shown for comparison.

AIRWAY LATERAL VIEW OF NECK Calcified tracheal cartilage rings Hyoid bone Epiglottis Thyroid cartilage Cricoid cartilage 3 2 5 4 Cartilage in the neck can calcify normally and this aids visualization Here they are outlined 1 LATERAL VIEW OF NECK

LATERAL VIEW OF NECK AIRWAY Calcified tracheal cartilage rings 3 AIRWAY Calcified tracheal cartilage rings Hyoid bone Epiglottis Thyroid cartilage Cricoid cartilage 2 5 4 1 LATERAL VIEW OF NECK

Where do you insert the tube at an emergency tracheostomy? Cricothyroid membrane

Emergency tracheostomy is performed at the thyro-cricoid ligament Emergency tracheostomy is performed at the thyro-cricoid ligament. Here a chest xray with a tracheostomy tube in postion. LATERAL VIEW OF NECK

Sections from the skull base extending inferiorly through the neck. LT MAXILLARY SINUSES SCAN LEVEL ZYGOMA ZYGOMA SPHENOID SINUS These are a set of axial sections through the neck from the skull base going inferiorly. There is a corresponding lateral x-ray to show the level of section Sections from the skull base extending inferiorly through the neck.

LT SCAN LEVEL MANDIBULAR CONDYLE MAXILLA EXTERNAL AUDITORY MEATUS NASOPHARYNX MASTOIDS Continuing inferiorly over the next several sections.

LT SCAN LEVEL MANDIBLE MASSETER MUSCLE MASSETER MUSCLE PTERYGOID MUSCLES PAROTID GLAND Note the parotid glands are of lower density than the surrounding muscles due to the fat present within the gland.

LT SCAN LEVEL SUBMANDIBULAR GLAND EPIGLOTTIS STERNOCLEIDOMASTOID MUSCLE Again note the difference in fat compared with soft tissue muscle. SUBCUTANEOUS FAT

LT SCAN LEVEL HYOID BONE VALLECULA PYRIFORM SINUS JUGULAR VEIN JUGULAR COMMON CAROTID ARTERIES Iodinated contrast was injected during the exam and it opacifies the carotid and jugular vessels

LT SCAN LEVEL STERNOCLEIDOMASTOID MUSCLE THYROID CARTILAGE VOCAL CORD The calcified thyroid cartilage is seen anteriorly

LT SCAN LEVEL THYROID CARTILAGE COMMON CAROTID ARTERY CRICOID JUGULAR VEIN Now inferiorly the cricoid cartilage is seen.

LT SCAN LEVEL THYROID GLAND CLAVICLE CLAVICLE FAT FAT ESOPHAGUS TRACHEA Air posterior to the trachea is in the esophagus. Typically the esophagus is collapsed unless eructation occurs.

Note hyoid bone moves anteriorly and superiorly with swallowing. SWALLOWING STUDY 1 2 Here successive images at 2 frames per second show barium propelled into the esophagus. 4 3 Note hyoid bone moves anteriorly and superiorly with swallowing.

THYROID SCAN Nuclear Medicine Nuclear medicine can evaluate tissue for function based on abiltiy to take up iodine. Here a radioactive iodine I-123 is administered.

SAGITTAL THYROID SCAN The superficial location of the thyroid makes readily accessible to ultrasound for evaluation of questionable palpable findings.

SAGITTAL SCANS LEFT LOBE RIGHT LOBE Ultrasound can assess palpable nodules and direct biopsy if needed. A nodule in the Rt. Lobe is marked

NUCLEAR MEDICINE THYROID SCAN Normal Hypo-functional Here are the normal thyroid scan made with radioactive Iodine shows relatively symmetric activity in the right and left lobes. The hypofunctional gland shows a large cold nodule inferiorly in the right lobe. This indicates non functioning thyroid tissue along with some mass effect. This is not a specific pathology but more suspicious for malignancy

PATIENT PRESENTS WITH WHEEZING AND NECK MASS IN MIDLINE AT STERNAL NOTCH

THYROID SCAN Nuclear Medicine Chest x-ray showing superior Mediastinal mass with displacement of the trachea to the right. Nuclear Medicine I123 thyroid scan shows lobular mass extending inferiorly from the thyroid indicating a thyroid goiter accounting for displacement on chest x-ray. Here in a different patient: Chest x-ray showing superior Mediastinal mass with displacement of the trachea to the right. Considerations would include enlarged thyroid tissue or tortuous vessels. Nuclear Medicine I123 thyroid scan shows lobular mass extending inferiorly of the thyroid indicating a thyroid goiter accounting for displacement on chest x-ray.   THYROID SCAN Nuclear Medicine

CORONAL CT SCANS SHOWS THYROID LESION. CT scan shows left thyroid mass at the level of the clavicles displacing the trachea to the right.

ARTERIOGRAM Internal carotid artery Intracranial carotid Maxillary artery Occipital artery External carotid artery Common carotid artery Facial artery 2 3 4 Here is a lateral image from a carotid angiogram. Iodinated contrast has been injected in a catheter with its tip in the common carotid artery. The contrast outlines the vascular tree. The catheter was placed from a femoral artery puncture and advanced retrograde into the aorta and into the common carotid artery. 7 1 5 6

WHAT VESSEL HAS TO BE LIGATED OR EMBOLIZED TO CONTROL EPISTAXIS IF PACKING NOSE FAILS? Maxillary Facial Lingual Superficial temporal Maxillary 64

normal Maxillary artery Here injection into the external carotid shows extravasation of blood from a branch of the maxillary artery compared with the normal. normal Maxillary artery 65

EMBOLIZATION Radiologist has directed a coil through the catheter to occlude vessels that were bleeding. 66

ASYMPTOMATIC BRUIT ON PHYSICAL EXAM

Normal Abnormal Ultrasound can measure lumen size of carotid artery and velocity of flow to indicate significant stenosis.

Ultrasound and arteriogram show high grade narrowing Normal Arteriogram is used for more anatomic detail to plan for surgery if a significant stenosis is found with ultrasound. Ultrasound and arteriogram show high grade narrowing of internal carotid artery due to atherosclerosis.

HOARSENESS

ASPIRATION A small amount of barium has extending anteriorly with aspiration into the airway. This can irritate the vocal cords and cause hoarsness. NORMAL A small amount of barium has spilled anteriorly with aspiration into the airway. 71

Hiatal hernia and reflux. Reflux from the stomach due to hiatal hernia can lead to aspiration with vocal cord irritation and hoarseness. Here a hiatal hernia is shown.

Here two patients with masses in their chest have involvement of the Here two patients with a mass in their chest have involvement of the recurrent laryngeal nerve causing hoarseness due to vocal cord paralysis. Here two patients with masses in their chest have involvement of the recurrent laryngeal nerve causing hoarseness due to vocal cord paralysis.

LARGE THORACIC ANEURYSM Here the aneuysm of the Aortic arch is stretching the recurrent laryngeal nerve causing damage leading to vocal cord dysfunction.

LUNG MALIGNANCY The lung cancer affects the nerve similarly leading to dysfunction. The patient may present to physician with the hoarsness as the initial complaint.

Aspiration into airway Mosquito bite Ethmoid transmission Amoebic meningitis can be contracted in southern states from swimming in warm lake water in summer by what route? Ear infection Aspiration into airway Mosquito bite Ethmoid transmission Ethmoid transmission 76

The thin cribiform plate can allow for transmission of nasal fluid. 77