Random_13 Flashcards
L5/S1 spondylolytic spondylolisthesis with severe bilateral L5/S1 neuroforaminal stenosis and severe bilateral L5 nerve root impingement.
L5/S1 spondylolytic spondylolisthesis with severe bilateral L5/S1 neuroforaminal stenosis and severe bilateral L5 nerve root impingement.
- Choroidal fissue is in continuation with the ambient fissure
- It hugs the hippocampus
- It contains choroid plexus and anterior choroidal artery
- It connects to the temporal horn anteriorly and superiorly
- Choroidal fissue is in continuation with the ambient fissure
- It hugs the hippocampus
- It contains choroid plexus and anterior choroidal artery
- It connects to the temporal horn anteriorly and superiorly
Osseous excrecence
Osseous excrecence
PCP pneumonia
- CXR - usually normal; may see subtle groundglass opacities
- HRCT
- Diffuse, symmetric ground-glass opacities are the dominant finding. There may be sparing of the subpleural lung in ~40% of the cases.
- Thin walled cysts in the same distribution as the ground-glass opacities may be seen sometimes. These predispose the patient to pneumothorax.
- Adenopathy and pleural effusions are rare. Consider other diagnoses in this case.
Choroidal fissure and temporal horn of the lateral ventricle are VERY close by, but they don’t communicate.
Choroidal fissure and temporal horn of the lateral ventricle are VERY close by, but they don’t communicate.
Uncal shift
vs
Uncal herniation
- uncal shift - just shifted out
- uncal herniation - bad - on coronal images, the uncus is on the other side of the tentorium! - blown pupil due to compression on the cisternal portion of the CNIII
- death occurs when there is mass effect on the adjacent midbrain
Wernicke’s encephalopathy
- Triad: confusion, ataxia, ophthalmoplegia
- MRI:
- T2 : symmetric increased T2 signal intensity in the
- mamillary bodies
- medial thalami
- tectal plate
- periaqueductal area
- T1 C+ (Gd) : contrast enhancement can also be seen in the same regions, most commonly of the mamillary bodies.
- T2 : symmetric increased T2 signal intensity in the
“Luxury perfusion”
- gyriform enhancement of the cortex following infarct
- usually a few days after the infarct
- due to breakdown of blood-brain barrier
Medulla foot
- Medulla region in India
- also called mycetoma
- fungal (eumycetoma)
- bacterial (actinomycetoma)
- commonly seen in those who walk barefoot, such as agricultural workers
- patients typically present with painless swelling and a draining sinus tracts. The purulent discharge typically contains colored “grains” representing clumps of the causative organism
- Stage 0 – Soft-tissue swelling, which can become nodular and expansive.
Stage I – Extrinsic pressure on the bone causing bone displacement or scalloping. No bone involvement.
Stage II – Periosteal reaction or reactive sclerosis as a result of irritation of the bone surface by the causative organism.
Stage III – Bone erosion or cavitation as a result of penetration of the periosteum and cortex.
Stage IV – Joint involvement with longitudinal spread along a ray of metatarsal bone and phalanx.
Stage V – Horizontal spread limited to two rays of bone and confined to the hindfoot, midfoot, or forefoot.
Stage VI – Uncontrolled infection with multidirectional destruction
Dot-in-circle sign
- This sign refers to the characteristic high intensity spherical lesions on both T1- and T2-weighted images with a tiny central focus of hypointensity, resulting in the “dot in circle.”
- The high intensity spherical lesions are classically surrounded by a network of low intensity material.
- High intensity spherical lesions represent granulomatous inflammation, and the low intensity tissue surrounding the round lesions relate to a fibrous matrix.
- The tiny central focus of hypointensity correlates to the fungus ball or grains.
Cspine CT
Look for prevertebral soft tissue swelling SUPERIORLY!!!
Intact Transverse Ligament C1/2
Torn Transverse Ligament C1/2
Transverse Ligament
- The transverse ligament of the atlas is a thick, strong band, which arches across the ring of the atlas, and retains the odontoid process in contact with the anterior arch.
- In Jefferson’s fracture - C1 fracture
- if transverse ligament is intact - stable - conservative management
- if transverse ligament is disrupted - unstable fracture - surgical management
- Radial tilt is measured on a lateral radiograph.
- The radial tilt represents the angle between a line along the distal radial articular surface and the line perpendicular to the longitudinal axis of the radius at the joint margin.
- The normal volar tilt averages 11degrees (2 - 20 degrees)
FMD
Fibromuscular dysplasia
- Intimal FMD - 5%
- concentric ring-like stenosis
- long segment of tubular stenosis
- Meidal FMD - 90-95%
- medial fibroplasia - 70%
- “beaded”
- medial hyperplasia
- preimedial fibroplasia
- medial fibroplasia - 70%
- Adventitial FMD - <1%
Complications
- renal artery stenosis and hypertension
- renal artery aneurysm - may be complicated by aneurysmal rupture in pregnancy
- dissection and thrombosis
Extracapsular silicone implant rupture
Silicone can be seen in breast tissue or lymph nodes after extracapsular rupture.
Classic ultrasound finding of extracapsular rupture is
- “snowstorm” appearance of echogenic scatter in the tissue adjacent to implant.
- “dirty shadow” posteriorly
Where is Zenker’s diverticulum typically located?
- posteriorly
- above the cricopharyngeus muscle
- at C5-C6 level
DDx for asymmetric breast density
- Inflammatory cancer
- Mastitis
- Trauma
- Invasive cancer (lobular)
CT dose
Rotation time doubled, mA one half
- rotation time S double
- mA half
- mAs same
Increase ptich
causes
Increased noise
Increase ptich
causes
Increased noise
Osteopetrosis
Sandwish vertebrae
Dermatomyositis
Sheet-like calcifications
Maissoneuve fracture
Note the spelling!!!
Maissoneuve fracture
Which surface (articular or bursal) is more commonly involved?
Which surface (articular or bursal) is more commonly involved?
articular surface!!!
- Anterior greater tuberosity cysts associated with tears
- Posterior cysts incidental
- Anterior greater tuberosity cysts associated with tears
- Posterior cysts incidental
DDx for decreased thyroid uptake
- Subacute thyroiditis
- Ectopic thyroid hormone production (eg struma ovarii)
- Factitious thyrotoxicosis
- Previous thyroid surgery
- Congenitally absent thyroid gland
- Expanded iodine pool
- Antithyroid medications
DDx for decreased thyroid uptake
- Subacute thyroiditis
- Ectopic thyroid hormone production (eg struma ovarii)
- Factitious thyrotoxicosis
- Previous thyroid surgery
- Congenitally absent thyroid gland
- Expanded iodine pool
- Antithyroid medications
Tracer for HIDA
- HIDA - Tc Hepato Iminodiacetic Acid (HIDA/Lidofenin) is the old term
- Currently used agents are
- PIPIDA - Tc Paraisopropyl Iminodiacetic Acid
- DISIDA -
Tc Diisopropylacetanilido Iminodiacetic Acid
Dx?
- If child is 2-3 y/o?
- If child is 4-8 y/o?
Meyer dysplasia
Dysplasia epiphysealis capitis femoris
- affects the paediatric hip.
- considered more of a normal hip developmental variation rather than a true dysplasia.
- bilateral in ~ 50% of cases
- 2 - 3 years of age
- male predominance
- usually asymptomatic
- Xray
- the affected epiphysis is smaller in size
- there are often multiple nuclei of ossification, giving the epiphysis a “morulated” appearance
- these then tend to fuse at ~ 5 years of age
- DDx: AVN (Legg-Calve-Perthes disease)
- 4-8 years of age
- AVN
- symptomatic - painful hips
Tidbits
Tidbits
- Perforated and extra-uterine IUD needs to be removed to prevent complications such as bowel perforation
- Ectopic pregnancies are less likely in patients with IUDs compared to patients without IUDs; however, in the setting of pregnancy and a properly positioned IUD, ectopic pregnancies are more likely than intrauterine pregnancies.
Perforated and extra-uterine IUD needs to be removed to prevent complications such as bowel perforation
Ectopic pregnancies are less likely in patients with IUDs compared to patients without IUDs (b/c overall pregnancy rate is lower); however, in the setting of pregnancy and a properly positioned IUD, ectopic pregnancies are more likely than intrauterine pregnancies.
Skull base connections
Anterior to posterior:
- pterygopalatine fossa
- vidian canal
- carotid canal
Cordoma vs Chondrosarcoma
- Cordoma
- enhances progressively
- may have mild restricted diffusion
- Chondrosarcoma
- enhances immediately
- no restricted diffusion
Meningioma vs Schwannoma
- meningioma
- intermediate T2 signal
- schwannoma
- high T2 signal
CN2 - 6 portions
- surrounded by dura - affected by meningioma (not Schwann cells or schwannoma)
- you can never have have meningioma involving the intracranial cn2 / chiasm
CN2 - 6 portions
- surrounded by dura - affected by meningioma (not Schwann cells or schwannoma)
- you can never have have meningioma involving the intracranial cn2 / chiasm
CN 7
- wrap around the nucleus of cn6 - baby bum
- cisternal - IAC - labyrinth - geniculate ganglion (vidian nerve) - horizontal tympanic - mastoid - extratemporal
- cn7 is normal to show enhancement after ganglion segment
- wrap around the nucleus of cn6 - baby bum
- cisternal - IAC - labyrinth - geniculate ganglion (vidian nerve) - horizontal tympanic - mastoid - extratemporal
- cn7 is normal to show enhancement after ganglion segment
CN11
- cervical 1-5
- foramen magnum
- pars vascularis
- SCM and trapezius
CN11
- cervical nerve roots 1-5
- foramen magnum
- pars vascularis
- SCM and trapezius
Tennis elbow
- common extensor tendinitis laterally
- most commonly injuried - extensor carpi radialis brevis
Tennis elbow
- common extensor tendinitis laterally
- most commonly injuried - extensor carpi radialis brevis
Throwing injury
- valgus injury
- ulnar collateral ligament at elbow
- UCL tear - T sign - contrast extravasate out extending ino supra recess and down the arm
- UCL laxity - medial condylitis
- ulnar neuritis
- ulnar stress fracture
- posreromedial impingement - olecranon osteophytes, trochlea chondral injury, loose bodies - tommy John Sx
- valgus injury
- ulnar collateral ligament at elbow
- UCL tear - T sign - contrast extravasate out extending ino supra recess and down the arm
- UCL laxity - medial condylitis
- ulnar neuritis
- ulnar stress fracture
- posreromedial impingement - olecranon osteophytes, trochlear chondral injury, loose bodies
- Tommy John Sx - surgical graft of the UCL
Ulnar nerve
- overuse neuritis
- direct injury - ulnar neuropraxia
- cubital tunnel syndrome
Ulnar nerve
- overuse neuritis
- direct injury - ulnar neuropraxia
- cubital tunnel syndrome
A supra-acetabular fossa
also known as pseudodefect of acetabular cartilage
A supra-acetabular fossa
also known as pseudodefect of acetabular cartilage
- is an antatomic variant whereby a focal defect is evident within the subchondral bone of the acetabular roof
- no associated bone marrow edema, cartilage damage or anything
- It is seen in as many as 10% of hips
- typically located at the 12 o’clock position both in the coronal and sagittal planes.