Random_10 Flashcards
DDx for pneumatosis intestinalis
- bowel necrosis
- most important and life threatening
- mucosal disruption
- peptic ulcer dz
- endoscopy
- enteric tubes
- trauma
- child abuse
- UC or Crohn’s disease
- increased mucosal permeability - often associated with immunosuppression
- AIDS
- organ transplantation
- chemotherapy
- steroid
- graft vs host dz
- pulmonary conditions - air from disrupted alveoli dissect along the bronchopulmonary interstitium and retroperiteoneum along the visceral vesels to the bowel wall
- COPD
- asthma
- mechanical ventilation
- ptx
- pneumediastinum
Cystic pneumatosis
vs
Linear pneumatosis
- cystic pneumatosis -
- well-defined blebs or grapelike clusters of spherical air collections in the subserosal region
- usually benign
- these air cysts may rupture and result in benign pneumoperitoneum
- linear pneumatosis -
- streaks of gas within and parallel to the bowel wall
- maybe benign or ischemic causes
Sigmoid volvulus
vs
Cecal volvulus
- sigmoid volvulus
- point towards LLQ
- proximal colon and small bowel are dilated
- cecal volvulus
- point towards RLQ
- proximal small bowel dilated
- distal colon collapsed
- vs cecal bascule - folding rather than a twisitng of a mobile cecum
Courses of pelvic muscles
iliopsoas
piriformis
pelvic diaphragm
- Iliopsoas
- psoas m. joins the iliacus m.
- lesser trochanter
- Piriformis
- anterior sacrum to
- greater trochanter
- Pelvic diaphragm
- anterior - levator ani
- posterior - coccygeus
Level of aortic bifurcation
Level of iliac artery bifurcation
- Aorta bifurcates into common iliac arteries at the level of iliac crest
- Common iliac arteries bifurcates at the level of pelvic brim - marked on CT by the transition b/t the convex sacral promontory and the concave sacral cavity
Denonvillier’s fascia
tough barrier b/t the prostate and rectum
preventing spread of disease from one organ to the other
Cervical malignancies
- 85% - squamous carcinoma
- 15% - adenocarcinoma
- low attenuation or isoattenuating compared to normal cervix - reduced vascularity, necrosis or ulceration
- II-b - invasion of the parametrium - no longer surgical candidate
Endometrial malignancy
Hematogenous spread to lung, bone, liver, and brain is much more common with endometrial cancer than cervical cancer
In adnexal torsion, the uterus is usually deviated to the affected side
In adnexal torsion, the uterus is usually deviated to the affected side
Trough sign
Vertical lucency
indicates an impaction from posterior shoulder dislocation
When disc material migrates from the parent disc, it is termed a “sequestered” or “free fragment”
:
When disc material migrates from the parent disc, it is termed a “sequestered” or “free fragment”
By noting the density differences b/t the “mass” and the thecal sac
By noting the density differences b/t the “mass” and the thecal sac
- if “mass” is denser than thecal sac - it is a bulged disc or sequestered disc
- if “mass” is isodense as the thecal sac - it is a Tarlov cyst/perineural cyst or conjoint nerve root
Types of spinal stenosis
Types of spinal stenosis
- central canal stenosis
- lateral recess stenosis
- neuroforaminal stenosis
Central canal stenosis
- most useful CT criteria for diagnosing central canal stenosis - obliteration of epidural fat & flattening of the thecal sac
- most common cause of central canal stenosis - fact degenerative disease
- other causes
- hypertrophy of ligamentum flavum - actually “buckling”
- paget’s disease
- DISH with ossification of the posterior longitudinal ligament
Neuroforaminal stenosis
Causes of neuroforaminal stenosis
- degenerative joint disease
- osteophytes arising from the vertebral body or the facet
- disc protrusion
- postop scar
DDx of diseae entities that have sequestrum
DDx of diseae entities that have sequestrum
- osteomyelitis
- EG
- desmoid tumor
- malignant fibrous histiocytoma
Ortner Syndrome
Cardiovocal hoarseness
- In this syndrome, the LRLN is injured as it loops around the aorta at the aortopulmonary window and along the outer side of the ligamentum arteriosum due to compression or traction caused by changes in the anatomy of the heart or great vessels.
- The left vagus nerve gives rise to the LRLN at the level of the aortic arch, which supplies muscles of the left larynx except the cricothyroid muscle (supplied by the superior laryngeal nerve).
- In isolation, laryngeal findings cannot differentiate RLN palsy from high vagal lesions; however, coincident pharyngeal constrictor atrophy and ballooning of the pharyngeal wall suggest pharyngeal plexus injury due to brain stem or central vagal nerve lesions. Moreover, coincident palsies/atrophy of the trapezius and sternomastoid muscles indicate associated spinal accessory nerve injury with involvement at the jugular foramen or high carotid sheath (above the level of the posterior belly of the digastric muscle).
- Evaluation of the heart, aorta, and supra-aortic thoracic vessels to rule out compression or traction along the thoracic course of RLNs should be part of screening for possible underlying causes of RLN paralysis.
“out of proportion TO…”
“Out of proportion TO…”
Fracture of the lateral talar process
“snowboarder fracture”
- often missed - anterolateral ankle pain related to such a fracture often mimics that of an anterior talofibular ligament sprain. Unfortunately, there is a high likelihood of developing osteoarthritis following lateral talar fractures, thus reinforcing the need for a correct diagnosis and optimal management.
- the lateral process is often identified inferior to the tip of the fibula. Any lucency, as in this index case, should prompt the diagnosis. Detailed evaluation of a well-positioned lateral radiograph with regard to the the angle of Gissane should demonstrate a well-defined smooth “V” shape of the lateral process.
- CT should be suggested for further evaluation if radiographic findings are equivocal, as well as to define the full extent of the fracture.
- lateral process fracture staging system (Hawkins) is:
Type I: Nonarticular chip fracture
Type II: Intra-articular, single fracture line
Type III: Intra-articular, comminuted
Normal and abnormal ankle xrays
Lateral talar process fracture
Gissane’s angle
Gissane’s angle
Left PICA stroke
ALWAYS look at the cerebellar hemispheres!
REMEMBER:
Cerebellar stroke - symptoms are IPSILATERAL!!!
Fibers have already crossed over!
When describing perianal abscess, it is important to differentiate b/t
intra-sphincteric
vs
extra-sphincteric
abscess
When describing perianal abscess, it is important to differentiate b/t
intra-sphincteric
vs
extra-sphincteric
abscess
Cause of post aneurysm coiling headache?
- RARE - delayed rupture of the aneurysm, which may have been ruptured partially during the coiling process
- COMMON - thrombosis of the aneurysm inciting an inflammatory response
The RLN arises from the vagal trunk in the thorax. On the left, the RLN arises at the level of the aortic arch; it crosses the aortic arch and hooks around the ligamentum arteriosum. On the right side, the RLN hooks around the first part of the subclavian artery, then ascends in the groove between the trachea and the esophagus. Because of its longer thoracic course, LRLN palsy is more common than right RLN palsy. The left RLN comes into close contact with left lung apex, aorta, pulmonary artery, ligamentum arteriosum, trachea, esophagus, and mediastinal lymph nodes and accordingly is vulnerable to compression or traction by pathological conditions of any of these structures.
The RLN arises from the vagal trunk in the thorax. On the left, the RLN arises at the level of the aortic arch; it crosses the aortic arch and hooks around the ligamentum arteriosum. On the right side, the RLN hooks around the first part of the subclavian artery, then ascends in the groove between the trachea and the esophagus. Because of its longer thoracic course, LRLN palsy is more common than right RLN palsy. The left RLN comes into close contact with left lung apex, aorta, pulmonary artery, ligamentum arteriosum, trachea, esophagus, and mediastinal lymph nodes and accordingly is vulnerable to compression or traction by pathological conditions of any of these structures.
The right and left RLNs supply all the muscles of the larynx except the cricothyroid muscle as well as sensory supply to the larynx below the VCs and the upper part of trachea (supplied by the superior laryngeal nerve).
The right and left RLNs supply all the muscles of the larynx except the cricothyroid muscle as well as sensory supply to the larynx below the VCs and the upper part of trachea (supplied by the superior laryngeal nerve - also a branch of the vagus nerve).
Left atrial, aortic, or pulmonary artery enlargement is encountered in various congenital heart diseases and can result in compression of the LRLN.
Aneurysms of different etiologies, direct injury in ductal ligation, or transcatheter closure of patent ductus arteriosus or upon repair of aneurysms are all associated with risk of LRLN palsy. Primary and secondary pulmonary hypertension, with enlargement of the pulmonary artery (as in our case) are also reported to cause LRLN palsy. Some patients with arteriosclerotic heart diseases can suddenly suffer LRLN paralysis due to rapid onset of left ventricular failure with sudden pulmonary hypertension with acute dilatation of the pulmonary vessels. This phenomenon has been termed dynamic dilation.
CT findings of VC paralysis include decreased volume of the thyroarytenoid and posterior cricoarytenoid muscles due to denervation atrophy, anteromedial rotation of the arytenoid cartilage, dilation of the ipsilateral laryngeal ventricle, pyriform sinus and vallecula, and thinning and medialization of the ipsilateral aryepiglottic fold. On coronal images, pointing of the VC and flattening of the subglottic angle are seen.
CT findings of VC paralysis include decreased volume of the thyroarytenoid and posterior cricoarytenoid muscles due to denervation atrophy, anteromedial rotation of the arytenoid cartilage, dilation of the ipsilateral laryngeal ventricle, pyriform sinus and vallecula, and thinning and medialization of the ipsilateral aryepiglottic fold. On coronal images, pointing of the VC and flattening of the subglottic angle are seen.
Acute Disseminated Encephalomyelitis
ADEM
- ADEM is an autoimmune demyelination disorder
- occurs 5 - 14 days after a viral illness or vaccination
- peak age 3-5 y/o
- The classic appearance is multifocal T2 and FLAIR hyperintensities in the brain and spinal cord (esp in the dorsal white matter) with multifocal neurologic deficits.
- The appearance of ADEM is often identical to multiple sclerosis, although ADEM is a monophasic self-limiting disorder.
- Steroids and/or plasmapheresis is the treatment of choice.
Pleural mets secondary to thymoma
“Drop mets”
Dry - no associated pleural effusion
Credo
Credo
A statement of the beliefs or aims that guide someone’s actions: “he announced his credo in his first editorial”.
Carpal boss
- bony protuberance at the dorsal base of the 2nd and 3rd metacarpals
- may be a result of a congenital ossicle (os styloideum), or traumatic, or degenerative osteophyte formation
- symptoms: pain and mass along dorsal wrist
Elastofibroma dorsi
- benign, fibroelastic soft tissue tumor
- possibly a pseudotumor, reactive in nature, due to mechanical friction of scapula against the ribs
- classically found in the infrascapular region, deep to the serratus anterior and latissimus dorsi musculature
- 60% bilateral
- F:M = 5:1, mean age 65 y/o
- often asymtomatic - incidentally found on CT
- may cause moderate pain and clicking, snappy, clunking of scapula with movement
- surgical resection if symptomatic
- no malignant transformation
- CT
- poorly defined soft tissue mass in the infrascapular or subcapsular region attenuation similar to that of adjacent skeletal muscle
- may have internal septations or scattered areas of fat attenuation
- atypical features such as bone destruction or intense contrast enhancement should raise the suspicion of tumor of a different cause - sarcoma, metastasis
DDx for intradural extramedullary tumors
- nerve sheath tumors - neurofibroma, schwannoma
- meningiomas
- other:
- primary: ependymomas, epidermoid tumors, paragangliomas, lipomas, plasmacytomas, and chloromas
- mets
Lymphangiomatosis
vs
Lymphangiomyomatosis
vs
Lymphangioma
vs
Lymphangiectasis
- lymphangiomatosis
- similar to lymphangiectasis - dilated lymphatic structures
- lymphangiomyomatosis
- middle aged women, thin walled cysts, PTX, tuberous sclerosis
- lymphangioma
- aka cystic hygroma
- lymphangiectasis
- dilated lymphatic structures
Pulmonary lymphangiomatosis
- smooth diffuse interlobular septal thickening
- diffuse effacement of mediastinal fat
- pleural and pericardial effusions
- mild mediastinal lymphadenopathy
Systemic lymphangiomatosis
Infiltrating mesenteric and retroperitoneal fluid density
- multifocal proliferation of lymphatic vessels
- clinical presentation depends on anatomic site and extension of involvment
- anorexia
- pain
- hepatosplenomegaly
- ascites
- resp distress
Emmy
vs
Academy
vs
Tony
vs
Grammy
- Emmy - TV
- Academy - film
- Tony - theatre
- Grammy - music
DDx of calcification in the lungs:
Pulmonary ossification
vs
Metastatic pulmonary calcification
vs
Chronic granulomatous disease
- pulmonary ossification
- dendriform pulmonary ossification
- true metaplasia of pulmonary fibroblasts into osteoblasts in response to chronic insult
- nodular pulmonary ossification
- due to repetitive alveolar hemorrhage
- dendriform pulmonary ossification
- metastatic pulmonary calcification
- chronic renal insufficiency
- elevated serum calcium
- chronic granulomatous dz
- silicosis
- amyloidosis
Dendriform pulmonary ossification
- rare, < 100 reported cases
- arborizing pattern of calcific reticular opacities and interstitial thickening, most prominent in peripheral lung bases
- demogrpahics: elderly males with co-existing chronic interstitial lung disease
- due to true metaplasia of pulmonary fibroblasts into osteoblasts
- not associated with bad prognosis
- centered in the diploic space
- expansile
- well-defined margins
- spoke-wheel, reticulated appearance
- avid enhancement
Sacralization of the right aspect of L5
with pseudoarticulation with S1
Gastric arterial supply
- celiac trunk - left gastric
- common hepatic - right gastric
- splenic artery - short gastric
- right and left gastroepiploic artery
