Lecture 6- (xray-head/peds), exam3 Flashcards
What are the standard skull radiographic views?
- AP or PA
- Lateral (or cross-table lateral)
- Oblique
Trauma views of skull must include what?
Trauma views must include 2 views 90* (both sides) from each other
What are these skull views?
- Right: lateral
- Left: AP
Skull trauma
- There is little correlation between what?
- What is the mainstay of emergent diagnostic neuro radiology?
- There is little correlation between skull bony injury and underlying brain damage
- CT is the mainstay of emergent diagnostic neuro radiology
What do these images show? What is the importance of these two different types of images?
Shows a skull fracture
* You were able to see the fx on the x-ray on the left but that is not always the case so CT like the one of the right is best
What views are these?
Face x-ray: to see sinus or zygomatic process
* Right: lateral face
* Left: AP face
Waters view of the skull
* What does it evaluate?
* Patient must be in what position?
* What is fuchs view?
- Evaluation of air-fluid levels of the maxillary sinuses
- Patient MUST be upright to evaluate air-fluid levels on this view
- Fuchs view is the same thing to evaluate for dens when patient cannot open mouth due to c-collar
What is the view of this image?
Waters View of the Skull
* you can see the frontal and maxillary sinuses
What do these images show?
- Air fluid level (on left)
- complete opacification (on right)
Sinus series:
* What position must the patient be in? What does it assess?
* What image is limited and what image is preferred?
* What does not require imaging?
- Patient MUST be upright; assess the sinusesfor air-fluid levels or opacification in complicated cases only
- XR use is limited, CT is preferred
- Uncomplicated sinusitis does not require imaging
What view is this?
AP face
Sinus Submentovortex
* What does it look at?
Looks at Ethmoid and Sphenoid sinuses from under patients’ chin
What image is this?
Sinus Submentovortex
What does the nasal bone series consist of?
Waters and lateral
* Only for nasal fx; no entrapment or soft tissue issue
Mandible series:
* What is it for? What does it look for?
* Hard to x-ray due to what?
- For mandible trauma, always look for afracture in two places, because ring-shaped structures, when they break, break in TWO places.
- Hard to X ray due to its contours and round shape.
What image view is this?
PA Mandible
What are these image views?
When your patient has this fx, what else do you need to look for?
We need then to look for the second fracture since mandible is ring-shaped. Do an oblique view since we don’t see it here
What view is this?
Oblique mandible
What view is this?
PANOREX Mandible
* Step-off is evident indicating fracture
What are plain films of the face reserved for (3)?
- Patients with a low likelihood of fracture
- Patients with suspected limited fractures such an isolated zygomatic arch fracture or mandible fracture
- Trauma patients who are too unstable for CT
Otherwise, CT Facial Bones without contrast is the modality of choice
What is the modality of choice of facial bones?
CT Facial Bones without contrast
What are the two zygoma components?
- Zygomatic arch
- Zygomatic body
- What is the most common cause of zygoma fx?
- What are the two types of fx can occur?
Blunt trauma most common cause.
Two types of fractures can occur:
* Arch fracture (most common)
* Tripod fracture (most serious)
What view is this and what does it show?
bucket handle view (Submental view) of the zygomatic arch demonstrating a depressed fracture
Tripod fractures consist of fractures through: (3)
1.Zygomatic arch
2.Zygomaticofrontal suture
3.Inferior orbital rim and floor
What do these facial bone ct show?
- Collapse of left zygoma and maxillary antrum with soft tissue edema and emphysema.
- Fractures extend into left orbital floor.
- Old deviation of the nasal septum suggest previous encounters.
What are the sxs of orbital blowout fx?
- Periorbital tenderness, swelling,ecchymosis.
- Enopthalmusor sunken eyes.
- Impaired ocular motility. Usually caused by entrapment of the inferior rectus muscle.
- Infraorbital anesthesia. Infraorbital nerve injury causes anesthesia of the maxillary teeth and upper lip is more reliable than numbness over the cheek.
- Step off deformity can be appreciated over the infraorbital rim.
From notes
How do orbital blowout fractures happen? (2)
They occur when the globe sustains direct blunt force.
* The first is a true blowoutfx, where all the energy is transmitted to the globe. Since the spherical globe is stronger than the thin orbital floor, the force is then transmitted to the thin orbital floor or medially through the ethmoid bones with the resultantfx. The object causing the injury must be smaller then 5-6cm, otherwise the globe is protected by the surrounding orbit. Fists or small balls are the typical causative agents.
* The second mechanism occurs when the energy from the blow is transmitted to the to the infraorbital rim causing a buckling of the floor. Entrapment and globe injury is less likely with this injury.
What nerve can be affected in orbial blowout fx?
CN5= maxillary brach
CT of orbits:
* Details what?
* Excludes what?
* What image view will be enough?
CT head:
* What does it rule out?
CT of orbits
* Details the orbital fracture
* Excludes retrobulbar hemorrhage
* Frequently CT Facial Bones will be enough
CT Head
* R/o intracranial injuries
What do you need to look for in an orbital blowout fx?
Look for external SQ emphysema
* Subcutaneous emphysema is pathognomonic for a fracture into a sinus or nasal antrum.
What are the different Le Fort fx? (3)
Le Fort I, II, III – each higher number is worse
* I: Maxilla fracture (floating palate)
* II: Maxilla, orbital rim and nasal bones (floating maxilla)
* III: II+ zygomatic arch fracture (floating face)
Le Fort Fractures:
* What will you note on PE?
* What will happen with le fort 3?
* What do you need to check?
* What is a common group of peoples does these fx happen in?
- You will note facial bone movement with exam
- Le Fort III is a craniofacial dys-junction and the patient has a dish-face appearance (flat face)
- Check mobility of hard palate
- Elderly who falls face first and MVA
What do these images show?
Lefort fxs
You are seeing a 75yo male in a c-collar following MVC where patient struck a steering wheel with his face. Airbags did not deploy. Exam shows entrapment of superior oblique muscle. You also note smell of ETOH from patient’s breath. Exam of torso/abdomen and all extremities show no abnormalities. What combination of imaging studies should you order to rule out pathology?
- CT Facial bones without contrast
- CT Facial bones with contrast, CT Brain with contrast and CT C-Spine with contrast
- CT Orbit without contrast
- CT Facial bones without contrast, CT Brain without contrastand CT C-Spine withoutcontrast
CT Facial bones without contrast, CT Brain without contrastand CT C-Spine withoutcontrast
Thyroid imaging:
* What is the initial study of choice? (lab and imaging)
* What tumors are more likely?
* What will identify the blood flow?
The initial study of choice is Ultrasound combined with laboratory evaluation of TSH
* Benign tumors are more likely (Thyroid Adenomas or cysts)
* US will identify the blood flow
thyriod
What are type of nodules that appear unstable? What will they require?
Nodules that appear unstable will require FNA
* Solid masses
* Irregular borders
* Microcalcifications
* Intranodal Vascularity
What does primary, secondary hypothyroidism cascade look like (TRH, TSH, TH hormone levels)? What about primary, secondary hyperthyroidism?
What are the ti-rads?
Thyroid Imaging Reporting & Data System - Provides recommendation for FNA or f/u US or leaving nodules alone
What is TR1, TR2?
- TR1: 0 points
– Benign, no FNA required - TR2: 2 points
– not suspicious, no FNA required
What does TR3 and TR4 entail?
TR3: 3 points
* mildly suspicious,≥1.5 cm follow up, ≥2.5 cm FNA
* follow up: 1, 3 and 5 years
TR4: 4-6 points
* moderately suspicious,≥1.0 cm follow up, ≥1.5 cm FNA
* follow up: 1, 2, 3 and 5 years
What does TR5 entail?
TR5: ≥7 points
* highly suspicious,≥0.5 cm follow up, ≥1.0 cm FNA
* annual follow up for up to 5 years
What is the percentage risk of malignancy for TR1-5?
- TR1:0.3%
- TR2:1.5%
- TR3:4.8%
- TR4: 9.1%
- TR5: 35%
Parathyroid Imaging
* What is the initial evaluation?
* What is the study of choice if US is negative?
* What should you conside?
- Initial evaluation with ultrasound
- Nuclear PTH Tc-99m Sestamibi is the study of choice if thyroid abnormality is not identified on US
- Consider clinical presentation and laboratory evaluation of Ca++ (issue with Ca -> low or high)
CNS Imaging:
* What does the imaging start with?
* What is the sensitivity of CT and MRI?
* What is rarely requested and why?
* What is the modalities of choice in a trauma pt?
- Imaging of CNS conditions effectingother parts of the body, usually beginswith higher-tech studies such as CT andMRI
- A CT is 58% sensitive for infarction within the first 24 hours. MRI is82% sensitive. If the patient is imaged greater than 24 hours afterthe event, both CT and MR are greater than 90% sensitive.
- In head trauma - Skull filmsare rarelyrequested because they only show thebony skull and do not revealabnormalities of the brain
- CT Brain usually combined with CT C-Spine, both without contrast, and are imaging modalities of choice in a trauma patient.
Computed Tomography:
* Recent technical advances in CT scanning dramatically increased what?
* Conventional CT scans take pictures like what?
* How big are the slices?
* How does the newer spiral CT work?
What do you need to make sure of for CT interpretation?
Brain CT Key Concepts
* White matter will appear as what on CT? Why?
* What will appear black on CT?
* What will appear gray?
* Acute hemorrhage will appear as what?
* After the administration of IV contrast, vascularstructures will appear what?
What slice is this?
The X: base of skill or bottom of brain
* You can see the frontal sinuses
What Ct slice is this?
The star-> higher up than x
What CT slice is this?
Happy face
What CT slice is this?
The sad face
* You can falx cerebri
What CT slice is this?
The worms
What CT slice is this?
The coffee bean
* top of the head
- Headache:
- No imaging in primary headaches is indicated when?
- Primary or secondary headache work-up rarely requires what?
- MRI with perfusion maybe useful when?
- What is a primary headache? What is a secondary HA?
- Light sensititivity can be seen in what?
- Aprimary headachehas no known underlying cause.Secondary headacheis the result of another condition causing traction on or inflammation of pain-sensitive structures.Headachedue to psychiatric disease is also consideredsecondary.
- Light sensititivity can be seen in many conditions other than meningitis such as ocular migraine, corneal abrasion or glaucoma and is not a severe feature requiring imaging.
With HA, blunt trauma imaging indicated when?
What does this show?
* What does this pathology result from?
* Patient will have what in their CSF?
* What are common causes?
Subarachnoid Hemorrhage
* Subarachnoid hemorrhage results from disruption of the subarachnoid vessels.
* The patient will have blood in the CSF.
* Aneurysm/A-V malformation or Direct Trauma
What does this show?
* Typically seen in who?
* Frequently also have what?
* An isolated version may be due to what?
Intraventricular hemorrhage
* Typically seen in trauma or hypertensive issues
* Frequently have subarachnoid bleeds as well (arrowheads)
* An isolated intraventricular hemorrhage may be due to rupture of subependymal veins.
What does this show?
Epidural hematoma
Epidural hematoma:
* What are the characteristics?
* Usually results from what?
* What is the classic presentaiton?
* What occurs quickly?
- Results from blood in the epidural space resulting in a biconvex lesion on CT Scan (football sign).
- Usually results from trauma to the temporal bone with disruption of the middle meningeal artery(origin)
- Classic presentation: LOC (>5min), lucid,Herniation
- Herniation occursquickly
What is this?
Subdural hematoma
Subdural Hematoma
* Bleeding occurs where?
* Usually results from what?
* What are the different types?
* These are commonly seen in who?
- Bleeding occurs between the dura and the arachnoid space resulting in acrescent-shaped lesion on CTScan.
- Usually results from venous origin
- These can be acute, subacute or chronic
- These are seen commonly in elderly and inalcoholicsand children under 2y.o.
* Smaller brains or atrophy
What does this show?
Hemorrhagic stroke