Dx Imaging III- Kettner - Logan Class of December 2011



Dx Imaging III- Kettner

9/12/05

: Education Portal-Databases and Teaching Files (search Google for case studies)

rad.washington.edu/ (online teaching materials(anatomy, musculoskeletal cases)

C/S Normal Anatomy

▪ Factors for attracting trauma:

-↑ ROM = ↑ risk for trauma (MVA)

-↑ transitional ROM areas (T/L junct, etc)

(Most mobile joint = glenohumeral jt)

▪ C/S xray series: APOM, neutral Lat, APLC (min of 3)

-5 view = obliques

-7 view (Davis Series)= flex/ext

▪ Criteria for accepting films:

1. All anatomy present: Base skull, occiput, inf endplate of C7

2. Contrast: ability to see cortical and medullary detail

3. Soft tissue visibility: see w/out a hot light (pre-vertebral and post-cervical tissues)

Method of evaluating C/S films (search pattern)

1. Soft Tissue:

▪ Pre-vertebral: check for swelling - impact trachea/pharynx (aerodigestion) ( compromise affects GI and Resp system

-3 categories occupy pharyngeal space: Hematoma, malignancy (smoking), retropharyngeal abscess

▪ Post-cervical: rarely any findings

-Nuchal lig may calcify ( simulate fracture of SP

2. Osseous Structures:

▪ Vertebrae: VB and posterior elements

1. C1: arch, post/ant tubercle

2. C2, C7 very prominent SP

3. C2 – transverse foramina angles down steeply (VB “bullet hole” appearance)

4. C3-C7 uniform in appearance

5. Transverse process

6. Pillar- attached to VB by the pedicle (“foot”) – oblong structure directly behind

-Commonly missed fracture (forced extension)- m/c C2 or C6/7

[pic]

3. Joints:

▪ ADI (55 yo)

- Outcome same w/ conservative care vs surgical tmt

- Outstanding features: hate extension (buckle ligaments – compress dura) ( bend forward, tension placed on tension on PLL and Flavum = ↓ compress (have both +/- for neurologic signs = diff day to day)

Flavum ossification: becomes continuous w/ apophyseal jt capsule (↑ symptoms) ( see at post, inf/lat portion of canal

SAF (superior articular facet) is border forming w/ the neural foramen

▪ Rostral/caudal subluxation: degenerative sublux that happens every time there is disc thinning (alter alignment of facets)

L/S: apophyseal jt arthrosis == create back pain (much more than discs)

HNP: ( 4.5mm & + signs (long-tract signs) = Fusion

• Slide showing fusion = did nothing the close the ADI gap!!

▪ If Normal = observe no more films

▪ If Normal = no restrictions (no test is 100% sensitive)

• AAI (atlanto-axial instability) of the ADI

Osseous Injuries of C/S:

• Classification of C1 Burst Fracture (Jefferson’s): fracture of ant or post arch

o Stable Jefferson fracture: intact transverse lig

o Unstable Jefferson fracture: disrupted transverse ligament (found on APOM) due to lat motion of lateral masses

▪ Spence et al: Total overhang or offset > 7mm of C1 lateral mass and C2 (sum of 2 sides): fracture and instability

• If < 7mm then just have C1 fracture (trans lig is fine)

▪ Oda et al: Atlantodental interval > 3mm

▪ CT shows a 4 part fracture: crack at lat mass connections ant and posterior

▪ No distinguishing clinical symptoms from an acute sprain!!

• Classification of Hangman’s fractures (VB-pedicle junction fracture of C2)

o Type 1 (65%) – undisplaced fracture involving the posterior body or any part of the ring (C2/3 disc remains intact)

o Type 2 (28%) – In addition to the fracture, the body of C2 is displaced anteriorly (>3mm) or angulated (>15◦). The C2/3 disc is disrupted

o Type 3 (7%) – Similar to type 2 but accompanied by U/L or B/L C2/3 facet dislocation w/ locking

o Radiographic signs: gap btn VB-pedicle junction, spinolaminar line shows posterior displacement of C2

o Distraction Dislocation: Hyperextension injury = occiput hits C2 spinous to cause hangman’s fracture ( force continues down to tear all ligaments btn C2/3 to cause dislocation

• Dens Fractures:

o Type 1: tip of dens (no clinical significance)

o Type 2: fractured at base (65%) – dens can potentially posteriorly affect cord or anteriorly the post arch of C1 can hit cord (unstable!!)

▪ Can have same result on cord as trans lig injury

o Type 3: dens and C2 body separated as a unit (can be unstable)

o Radiographic presentation: can shoot thru Foramen magnum – dens should be vertical

▪ If tilts 3◦ could be fracture ( if 5◦ then it is a fracture!!

• Flexion Teardrop (burst) Fracture (very severe!)

o Typically affecting C5 – not to be confused w/ extension teardrop fragments off C2 or C3 which are usually stable injuries

o Devastating, unstable injury produced by a combination of flexion and axial loading; 49% due to diving and 36% due to MVA’s

o High incidence of neurological damage, w/ the majority (56%) developing quadriplegia

o Radiographic Presentation: Teardrop shaped fragment off anterior C5 VB

• Wedge Fracture – Acute Fracture of the VB: Posterior VB is normal and the anterior VB is more compressed

o Hard to see in developing spine because all VB angled anteriorly due to under developed growth plates

o Zone of Condensation: bone has been compressed into bone!! ( appears sclerotic

o Step off: fragment of bone knocked loose of the ant VB

o STS: soft tissue swelling (not all fractures – especially early on)

o Can have osteophytosis due to old, un-diagnosed VB compression fracture (now become pain generators)

• HNP Complicating C/S Trauma

o Very little was published about it prior to MRI

o High assoc of unstable injuries and HNP (54%); especially w/ facet subluxation or dislocation. Neurological damage reported w/ closed reduction over an unrecognized…

o MRI: subluxation followed by extrusion of disc into the dura

▪ Radiculopathy (NR), myelopathy- affect cord (may see both UMN and LMN signs)

▪ Contusion: compression of cord causing myelopathy (↑ cord signal = looks bright)

• 25yr female w/ hemiparesis: (which precedes paraplegia)

o Diff Dx: Heart stroke, MS, Cord tumor

o Actually was a cord contusion (no need to spinal tap!!)

o Developed a syrinx: contusion drained down spinal cord leaving a space in cord

▪ Syrinx in C/S attacks the Gleno-humeral jt (↑ dislocation)

▪ Hemorrhage: can be differentiated from contusion on MRI

▪ Fat suppression technique: fat appears blk on MR (do when want to see the water and not the fat signal = more sensitive to detect pathology (water)

o Radiographic presentation: C5/6 – see spinous gapping, naked facet, angle > 11◦ (if NR affected: C5/6 IVF affects C6 NR and dermatome)

o CT scan: soft tissue (can’t see trabecular bone) and contrast (makes cord visible and see bright in subarachnoid space)

▪ Dura is not symmetric = extradural compression (indicate HNP or osteophytosis causing stenosis)

▪ Side marking of CT is opp (orientated as if looking at patient from their feet to their head)

• “Spondylolisthesis” of C/S: actually is a dislocation

o Radiographic presentation: see facet dislocation (flex, rotation injury to “jump” facet off the other = Locked facet)

o Normal spondylolisthesis in C/S = congenital due to dysplasic facet or pedicle ( if don’t see these = is a dislocation!!!

o Bow-tie Sign: of the facets – shows dislocation?

• Pillar Fracture: extension injury

o Facet surface becomes horizontal (compressed)

o Also see IVF stenosis: trauma becomes arthritide (bone hypertrophy ↓ neural foramen)

• Impaction fractures: produce zone of condensation

o C6/7: ant displacement of sup VB, lucent line on sup End plate, wedge deformity

o CT: uncinate process fractured and VB is compressed

• Vertebral A Occlusion

o More common than previously thought and it can produce neurologic deficit

o Vulnerable because of t fixation w/in the foramen transversarium (C2-6)

o It should be suspected in pts w/ facet dislocations as well as fractures of the foramen transversarium

o Mechanism: stretching and tearing of the intima and media, dissection (distal), mural thrombus, clot propagation (smaller clots from large clot), and occlusion

o Slow progression of this process may allow for an asymptomatic period (hrs to days)

o Symptoms: dysphagia, dysarthria (speech affected), dizziness, disorientation, U/L neck pain and HA, dys-coordination

o Digital Subtraction Angiogram (subtract all but Vert Artery): see ↓ diameter in section of Vert A

o MR: see signal void (blk) of Vertebral A flanking VB’s (normal)

▪ Absence of the void = no blood flowing (sign of artery occlusion)

▪ MRA: subtract all structures but vessels

o Clinical symptoms: multiple cerebellar infarctions (MR shows up wht = ↑ signal) – can occur

o Wallenberg syndrome: when infarction happens in the medulla due to vert artery occlusion

o Spinal Manipulation inducing Vert A Occlusion?

▪ 136 cases ever reported (don’t know if had it before?)

▪ Risk factors: higher incidence of migraines, HTN,

▪ Id risk factors, Id adverse/neurologic deficits, rush to ER

▪ Author: Halderman S. - Random complication of ANY neck motion (“sudden onset of acute and unusual neck and/or head pain may represent a dissection in progress and be the reason a pt seeks manipulative therapy…”

• Flexion injury

o Articular processes “perched” on top of each other (flexion injury) - unstable

• Spondylolysis

o “Scotty dog” – defects occur in “neck”

o Occurs m/c < 10 yo!!!

o Why occur? – foot of Scotty dog is banging into neck by repetitive hyperextension = eventually get a stress fracture

o May develop excursion – movement of spinal segment = spondylolisthesis (usually occurs w/in 2 yrs after spondylolysis)

▪ Degenerative spondydolisthesis: >40yo, female, arthritic at L4/5

▪ Grading by %: msr endplates ( perpendicular line to inf VB (line from here to back of inf VB = %)

▪ Sup VB tends to resorb bone due to traction & S1 rounds out

o Spondylolytic spondylolisthesis: not pain generator in adult (pain only while evolving in kids) unless L5 is unstable

▪ If pain = facet syndrome, myofascitis, etc

o TMT: treat symptoms, can “move bone back”

▪ Break filled in w/ fibrocartilage – some fear HVLA tmt could disrupt this and make it unstable (no supporting research)

▪ Traction technique for radiographs: if unstable = listhesis reduces

▪ Displacement anterior when add compression

• Unstable if add traction displacement + compression displacement > 3 mm

• Rehab protocols need to employed

o IN Pediatric population: Acute Spondylolysis

▪ Kid w/ back pain, neg films, neg bone scans, unresponsive to treatment

▪ SPECT: see 2 hot spots showing abnormal activity in the pars (bracing is an option for tmt – have healing bone)

• If cold still = healing will not occur (no need for bracing)

• Compression Fracture

o Wedging, zone of condensation, step off fragment of VB (may look like osteophyte!)

o ON AP film: don’t see sharp sup VB end plate (suspect but confirm on lateral film)

o CT: fracture lines thru VB

▪ Bone window – “double cortex” sign (compressed into VB)

▪ Bone scan is HOT

• Post traumatic spinal stenosis

o CT: see fracture fragment significantly stenosing the canal (also see signs of compression fracture)

o See root signs if at level of cauda equina

• Pathologic Fractures: (MR or biopsy required)

o Vertebral Plana: > 13% difference in height of post VB (could be from OP)

Lower spine and LE

• Acute dislocation of Femur Head

o Injury: impaction on knee (MVA – drives femur posterior)

o Fractures occur w/ this injury:

o CT: posterior column of acetabulum fractured and completely displaced ( allow femur head to dislocate easily

o Legg-Calve Perthes ds: Femur head necrosis = fracture line of growth plate – sclerosis

▪ Idiopathic ds (pediatrics)

▪ Diff Dx for kids hip pain & limping: transient synovitis (resolves in a few days), LCP, Infection of hip jt (usually not febile)

▪ Hip pain in teen years: Diff Dx adding SCFE (slipped capital femoral epiphysis – physis is fractured and head slips off)

o Osteonecrosis in the adult: male, 40yo, trauma, DM, use of corticosteroids, etc

▪ Intermittent hip pain (activity pain) ( starts to hurt at rest

▪ Biopsy: intra-osseous HTN (pressure too high ( collapse veins ( arteries can’t get blood in ( bone necrosis

• Mechanism: Start w/ edema inside bone – collapse vein

▪ Causes: lupus, corticosteroid use, DM, trauma, alcoholism

▪ Neck of femur gets fat (remodels) to provide support as the epiphysis degrades

• Get new epiphysis 2 yrs later but biomechanics already altered

▪ MR: HTN shows signal void at femur head

• MOT: myositis ossificans traumatica

o See space (cleavage plane) dissecting piece of bone and femur cortex

o Complication of mm injury (will have a contusion) – use RICE for local management

o Contusion starts to resolve – palpation shows induration (hardening of tissue) – few weeks

o 3rd week – see bone in the soft tissue (keep growing bone for 6 mos)

▪ Can block joint (↓ ROM) = extra-articular ankylosis (outside jt)

o Soft tissue Sarcoma: can look identical to MOT

▪ Stress fracture – have malignancy in differential (sarcoma)

o Heterotopic (aka: Heterotrophic) bone formation – also paraplegia, coma

• Osteochondroma

o Calcification in bulbus growth outside of hip joint

o M/C benign tumor of the skeleton (usually around knee)

• Stress fracture

o Hamstring injury pt (had 2 stress fractures

▪ 2 periosteal rxn along femur (not normal); bone scan showed 2 hotspots w/ linear area on opp side of femur cortex

▪ MR: ring of high signal intensity (periosteal rxn)

▪ Concern w/ the marrow – showed no change from other side (rule out osteosarcoma, osteomyelitis)

o 2 forms:

▪ fatigue fracture (abn force on normal bone)

▪ insufficiency fracture (normal force on abn bone – i.e; OP bone)

o Cod-fish Vertebrae: bone being taken away faster than it can be re-built

o NOT acute pain (low grade ache)

• Patella (Knee jt fractures)

o Cut mechanism of injury; athletic cleats fix feet to ground, knee bent ( external forces to internal of knee ( vectors on the patella ( cause lat dislocation of patella

▪ Subluxed patella: hematoma pushes patella laterally

• Degrees: can break off condylar or patellar cartilage during dislocation

▪ Collapse and knee is deformed – knee can be reduced by bring patella back to position (can cause osteochondral fracture) ( cause further damage to knee jt

• Iceberge effect: see only calcified fragment when attached to larger piece of cartilage

o Lat Plateau fracture (due to lat blow) – cartilage disrupting the joint (complicate fracture = ↑ risk of OA)

o Med column fractured – displace fragment inferior

▪ MR: see bone bruise – see blk moddled appearance of the bone (low signal surrounded by high signal fat)

• BME: bone marrow edema (occurs w/ ACL tears, etc)

• Get pain but goes away – complication can be osteonecrosis!!! (if pain comes back)

• Not same as sub-periosteal hematoma

o Meniscal injury on MR: degenerative tear shows bright

▪ Acute tears: wht line from articular surface to articular surface (cartilage causes clicking, popping, pain)

• Must be repaired (grade 3 tear)

• High signal = edema w/in tear of the meniscus (normal should all be blk)

• Elbow: constitute 6% of all fractures

|Adult |Child |

|Radial head (50%): |Supracondylar (60%) |

o FOOSH: ”fall on outstretched hand” (m/c: 3 fractures: radial head, humeral greater tuberosity, scaphoid fracture)

o Humeral condyle compacts the radial head (impaction – see some sclerosing and some angulation of the radial head)

o Little league elbow:

▪ Group of pathologic changes in young throwers (bone is still growing)

• Mechanism: pull on medial side and compaction of lateral side

• Jt will lengthen abnormally, epiphysis closes quicker (↓ blood flow) ( OA

▪ Also seen to arise from the tennis serve and football pass (baseball)

▪ Medial epicondyle fragmentation and avulsion (epiphysis), growth alteration of the capitellum, osteochondritis of the radial head, hypertrophy of the ulna and olecranon apophysis

▪ C (capitellum)R(radial)M(med epicon)T(trochlea)O(olecranon)L(lat epicon) ( order of epiphyseal development (2-12 yo)

• “Come rub my tree of love” (order of maturation of the growth plates)

• Salter Harris fracture (grade 1: crack thru physis)

o Pediatrics 75 yo) |

| | | | | |

| | | | | |

Differentiate btn Collies & Smith: Find thumb on palmar side to determine direction of displacement!!

*Collies is the 1st osteoporotic fx (~50 yo) ( 2nd is the codfish vertebrae ( 3rd is femoral fx (>80 yo – 1:5 females and 33% will die)

|Salter-Harris Classification of Fractures | |

|Type 1 |Fracture of physeal plate |Space btn the epiphysis and metaphysis |

|Type 2 |Fracture of physeal plate and metaphysis (m/c) |Metaphysis (end of bone) |

|Type 3 |Fracture of the physeal plate and epiphysis including the articular |Epiphysis (separated portion) |

| |surface | |

|Type 4 |1-3: fracture of physeal plate, metaphysis, epiphysis | |

|Type 5 |Physeal compression deformity | |

[pic]

• Dorsal displacement of radial epiphysis (looks like the radius has gone to palmar side) – type 1

o Not a wrist dislocation because radial epiphysis and lunate articulation is unchanged

o Also see Carpal coalition (lunatotriquetral coalition): like a congenital blocked vertebrae

• Wrist articulations (collinear relationship – lat view): Radius (ulna w/in borders) ( lunate ( capitate ( 3rd metacarpal

o See luscent line (fat plane along pronator quadratus – important line in determining fracture – i.e; should be straight on dorsal/radial side

• .

• Wheeless’ Textbook of Orthopaedics (online): good for review (also use in practice)

o

o Caralinskis website?

• Torus fracture: (lip of top of architectural pillar = torus)

o m/c fracture of the wrist in pts aged 6-10 (FOOSH mechanism) – good prognosis

o Typically located 2-4 cm from the distal growth plate

o Classically an impaction injury – ALWAYS PROXIMAL TO A JOINT

o Xray appearance: see a “lip/bump” interrupting the cortical margin of bone (seen best on lat view)

• Wrist evaluation:

o Plain film assessment

o The 3 arcs of carpal alignment:

▪ 1st: prox row on prox cortex ( should be continuous

▪ 2nd: on distal aspect of prox row

▪ 3rd: cortex around capitate and hamate

▪ Dorsal Perilunate dislocation: lunate not articulating w/ capitate anymore (capitate is the one dislocated)

• Window of repair 10days

• See breaks in all of the arc lines

o Aka: Gilulas’ lines

o Joint spacing

o Articular alignment

o Soft tissue assessment

o Wrist series: 4 view recommended

▪ Fine grain screens reduce the rate of false neg’s

▪ Navicular fat stripe sign (+) in 90%

▪ Clinically:…..

• Scaphoid fx:

o M/c carpal bone to fx

o Age of occurrence betn 15-40 yrs

o Rare in children

o m/c for occult fx

o Mech: complex injury patterns

▪ Same amt of hyper extension and radial flexion

▪ FOOSH

▪ 70% involved WAIST?

▪ Bone scans (+) w/in hrs of injury (6-16%)

▪ When scaphoid fr doesn’t heal – pin is needed (Herberts pin)

▪ Avascular necrosis can occur – retrograde susception to nonunion

• Scaphoid fracture complications

o Prox waist fracture, prox poll fx may demonstrate avascular necrosis (15% of scaphoid fractures)

▪ Vascular pattern: SLAC wrist

• Scaphoid has 2 pieces (nonunion)

• Cortical margin is interrupted (erosion & cyst in lunate)

• No radial compartment – OA

• Mechanism of SLAC wrist: scaphoid fx ( nonunion( every time clinch fist = capitate migrates proximally ( destroys fx fragment and the lunate! (eventually wrist will spontaneously fuse)

o Nonunion (30% of wrist fx)

o Carpal instability

o Radiocarpal degen arthritis

• Colle’s Fx xray appearance: see luscency where screws were put in, marked osteopenia in prox radius/ulna and all carpals (starting OA)

o Allodynia: pt feels pain on slight touch (also seen in fibromyalgia)

o Hyperalgesia: pain stim becomes magnified pain

o Both above are nerve injury

o CRPS: complex regional pain syndrome (aka RSDS, Sudeck’s atrophy)

▪ S/S: allodynia, hyperalgesia, and osteopenia (↑ sympatheticotonia)

• Can develop in opp limb or whole body mediated thru spinal reflexes

• See pain out of proportion to injury = think CRPS

• Treatable early on: exercise and mobilization (restore sympathetic tone)

o Can’t do in acute phase! –

o Drugs and sx option (not always good results)

▪ Type 1: no nerve lesion can be identified (whole arm hurts)

▪ Type 2: identifiable nerve lesion

• Kienboch’s Ds

o Avascular necrosis of the carpallunate

o 1st described by kienboch in 1910

o Produces great pain and loss of function

o Males – females = 9:1

o 20-40 yo

o Previous hx of acute trauma or repetitive trauma

o Plain films neg – 12 mos

o Pos during re-vascularizatrion stage (6mos – 4 yrs) the repair/.remodeling stage (1-2 yrs) and deformity stage

o Bone scan will be positive early

o MR is the most sensitive

▪ Appearance: bone marrow edema (low signal on T1 image)

• Triangular fibrocartilage tear: ulnar side of wrist – meniscus attached to ulna and radius by lig’s

o Frequently seen in athletes who experience repetitive wrist loading particularly gymnast, pole vaulters, martial arts strikes and blocks

o Presentation: wrist pain and clicking

o MR dx: appears ↑ signal intensity (should be black)

• Thumb injuries:

o Gamekeepers Thumb: avulsion of collateral ligs of thumb (stress views and MR)

o

• .

MT: 50Q’s; describe cases – findings, dx, etc

Syllabus: topics of normal anatomy & differentials?, axial/apendicular deg ds; most exam is trauma based (ch 4) – look at image captions, chapter summaries

Neuroradiology Section: 2 specialties

• Skull, brain, cord

• Head & Neck : skull, sinus, orbits, neck

• Cord: most central neurologic deficits are peripheral – radiculopathy or neuropathy (CNS, PNS, ANS)

o CNS branch (myelopathy NOT radiculopathy – is m/c) – spondylotic myelopathy (compressive)

o Tumor and MS (looks like spondylosis before imaging)

o S/S: UMN findings,

o DDx depends on location (presentation of cord disorders)

▪ Extradural: outside both cord and dura

• Imaging:

o Thecal sac (dura) deformed/compressed from outside-in

o Extra “mass” seen in canal

o CT myelogram or T2 MR ( thecal effacement (compress) or min CSF visualization

o DDX: degenerative ds (95%), trauma, iatrogenic, hematoma (canticoagulation), abscess, tumor

▪ 70% malignancy become extradural problem

▪ >50 = spinal stenosis

▪ 3 cm (diff dx: 1◦ malignancy = bronchogenic | | |

|carcinoma, 2◦ mets, abscess) | | |

|Atelectasis: insufficient inflation | | |

|2nd cause: bronchogenic carcinoma (displaced structures – magnet | | |

|like pull w/ alveolar collapse) | | |

|1◦ cause: fissures | | |

• Technical issues:

o HIGH kVP (> 120 KV)

o Right Hemidiaphragm at the 10th R rib (inspiratory examination – anything less = expiratory examination)

o Rotation: never get pts perfectly PA – can appear clavicle dislocation

▪ Cause prominent hilum on side of rotation (may simulate denser hilum as w/ bronchogenic carcinoma – radon gas, 2nd hand smoke)

• Bronchogenic carcinoma: Semental HI??

o Tumor growing – air gets thru (expand) on inspiration but not on expiration (contract) ( Collapse of alveoli ( magnet like pull on all structures

▪ i.e; heart shadow on one side of T/S, tracheal deviation, etc

▪ Easy sign: med borders of the clavicles equal distance from spinous process (one will be typically wider – most common w/ scoliosis

• If radiograph in AP: heart will be enlarged by 13% (false diagnosis of cardiomegaly) – even larger w/ expiration

• Anatomy:

o C/S paraspinal soft tissues: look for calcification (common) – either vascular (atherosclerosis – carotid bulb) or adenopathy (

▪ Bruit…..95%,…..

o Breast density: extends beyond the thoracic wall (not in thorax but ON the thorax – differentiate masses)

o Diaphragm

▪ Right heimidiaphragm is higher = normal finding

• Pneumoperitoneum – air outside the GI tract (rupture)

o Ulcer or tumor ( ER situation

▪ Anterior Costophrenic angle (sharp, acute angle on both sides)

• Blunting of angle = sign of pleural effusion

• Meniscus sign: fluid drawn up (pleural effusion) of sides (like test tube meniscus)

• Causes of pleual effusion: CHF, Pneumonia, malignant tumors

o Posterior costophrenic angle: seen on lateral view

▪ More sensitive to pleural effusion (blunting)

▪ Mesothelioma & bronchogenic carcinoma (asbestos + smoking = ↑ 30% risk of BGC)

o Soft tissue below diaphragm = most liver

▪ Fundus of stomach

▪ Colon (gas)

▪ Liver (homogenous)

▪ Spleen – next to colonic flexure (if can see = splenomegaly)

▪ Multiple dilated loops of small bowel w/ air/fluid levels = ER situation (hallmark of small bowel obstruction – progressive pain, perforation complication ( peritonitis (contents of GI tract – chemically corrosive and bacteria)

• Caused by adhesions – bands of fibrous soft tissue (edema becomes adhesive fibrosis) – post sx

• Hernia strangulation – incarceration (not able to put bowel back = irreducible)

• Colon carcinoma – tumor strangulates loop of bowel (closes the lumen)

• Skeletal abnormalities:

o Congential (short clavicle)

o Trauma: rib, clavicle, VB fx, arthrotides of jts (RA, OA),

o Hyperparythroid – rib notching

• Central shadow:

o Tracheal deviation: presumption of tumor, thyroid ds, parathyroid masses, lymphadenopathy) ( push trachea

o Cardiac sillouette: level of aortic arch – width of mediastinum should be same as vertebral column

▪ Measure heart at widest point to the midline and sum the interval (cardiac component on numerator)

• Denominator is Thoracic component (rib to rib????)

• CT ratio should be less than 0.55 in adult (if > cardiomegaly)

o Principle causes: HTN (dilation and hypertrophy w/ L-vent heart failure) – occurs in 50 million Americans

o Valve ds – irregular borders – insufficient or irregular closing (stenosis)

o Right sided heart failure (chronic lung ds) – cor pulmonale (lung ds causing heart ds) ( affect L side later

▪ Pulmonary arteriole HTN: heart works harder to pump blood to lung (causes cor pulmonale)

o Hilum: normally see main pulm artery w/ branches (higher on L side) – only opacities normally seen in the chest film (wht lines)

▪ Normal structure on right = horizontal fissue (opaque) – separate middle from upper lobe (may be seen)

▪ Numerous lymphnodes (can’t see unless calcified = adenoma, infection)

▪ 2 structures in the hilum (vessels and nodes)

▪ HTN (primary and secondary)

• Primary: rare, middle age females, pulmonary arteriole vessel thickens until lumen disappears (↑ pressure – rapid heart ds fatal w/in 2 yrs)

o Idiopathic nature

• Secondary

▪ Shunt vessels – vessels become prominent in hilum

▪ Nodes: tumor, metastisis, benign cause is sarcoidosis (immunologic disorder afflicting African American females – lymphadenopathy on both sides of hilum

• 1,2,3 sign (paratracheal nodes, and B/L hilum nodes)

• Skin test (Kvein test) – current test is angiotension converting enzyme elevation

▪ Vessels vs nodes: biopsy lymph nodes (differentiate CT scan)

Chest Radiology (Dr. Hahn)

• Normal pectoral muscle line (lateral thoracic wall) – B/L sign

o Mistaken for Pneumothorax: looks like a thin line, vertical along lateral chest wall

• Consolidation: malignancy will also see destruction of surrounding structures

o See “mass” in Upper R lung

o Tomograph shows notch in the rib under the mass = neoplasia

• Calcification of the diaphragm

• Calcification of 1st rib costocartilage (normal)

• Elevated R side diaphragm = scoliosis causes high diaphragm on side of convexity (also will see vertebral column deviation)

• Curvilinear calcification at the aortic arch = (“thumbnail sign)

• Calcification in the lung apices- calcification of the pleura due to infection (histoplasmosis, TB, etc)

• Cyst in the lung apex: Well defined border, oval shaped, luscency = normal

o Lung seen between the 1st rib and the subclavian vessels = lung apices

Dr. Kettner back

• Final 50Q; m/c ( some multiples (differential dx); cases

• Degenerative ds: OA, neuroarthropathy, synovial osteochondromatosis (aka?)

• *Trauma: axial, appendicular, mechanism of injury, complications of trauma (myosistis ossificans)

• Epinem list (i.e; Jones’ fx, etc)

• Head/neck neuroradiology: thyroid mass, tumor, aneurysm, etc (major conceptual understanding)

• *Chest: 5 steps of search pattern, causes for tracheal deviation, etiology for enlarged heart on specific side (cor pulmonale);

• DDX for nodule, mass, etc (clinical context)

Pitfalls in chest radiology

• Bumps of heart: aortic arch, pulmonary artery, LV (sup to inf on R side)

o RV bump on L side

o Extra bump = is it lung or mediastinum?

▪ Mediastinal mass – deflects pleura laterally (should only be as big as vertebral column at level of the aorta)

▪ 5 T’s:

• Thyroid descending from neck, embryologically thyroid developed lower

• Thymus did not atrophy as much as normal (thymoma – high assoc w/ Myasthinia Gravis – neuromotor junction)

• Teratoma: pre-malignant tumor (5% progress to cancer) – clump of all times of tissue (ectoderm, mesoderm, etc)

• Lymphoma

• Ascending aneurysm

• Lung abnormalities: + or – densities

o Summation artifacts: add up densities of surrounding structures around part of lung (rib, cartilage, artery) – appears as a cavity (lucency)

o Cavitary structure: has opaque density inside w/ an air fluid interface (AFI) – see in the abdomen (small bowel obstruction)

▪ Not summation! – m/c reason is lung destruction following infection, 2nd cause is tumor (*almost always malignant, m/c squamous cell carcinoma)

• Neovascularity – new blood supply to tumor but can’t support the center of the tumor (lucent)

• Smoking leading cause of lung cancer ( 2nd is passive ( 3rd is radon

o Hiatal hernia: see air bubble in fundus of stomach (have reflux) ( seen w/in the heart on film (actually behind the heart)

o Tortuosity (serpentine): change in the ascending aorta (enlargement of the mediastinum) – HTN shows wider aorta (abnormal, elevated pressure)

▪ Radius of curvature should come up to the aortic arch (uniform)

▪ If goes above = something else unless aneurysm

▪ Do CT if unsure

o Area of scar (subsegmental atelectasis) – results from immobilization of the lung (avoid breathing due to pain post-sx) ( cough to avoid scar or pneumonia

• Diff Dx for Solitary pulmonary nodules: infection & neoplasia (pos density)

o Anything seen in lung that doesn’t belong = same default victane categories

• Medial Mediastinal masses: bronchogenic and lymphoma

• Posterior mediastinal masses: neurogenic (neurofibroma, meningioma, gangioneuroma)

o Diff includes: thoracic aortic aneurysm; paraspinal masses (hematoma, myeloma)

• Vessels off Aortic arch

o Brachiocephalic ( R carotid, R subclavian

o L carotid

o Left subclavian

o Anomalies: L subclavian may come off the brachiocephalic

▪ R sided aortic arch (usually on L – tetrology of flow-cyanotic heart ds)

▪ May get double arch (traps the trachea) ( stridor and dyspahagia

• LA more posterior than the LV

• Coronary angiogram – gold standard for eval of CAD ( 700,000 MI per year (death every 20 sec)

o Pressure on chest, dyspnea, diaphoretic (sweating); preceeding by “sense of impending doom” ~ 12 hrs earlier

o Risk factors: male, DM, age, HTN, ↑ cholesterol

▪ 1/3 of MI do not have any classic risk factors

o Angina: mm do not have adequate profusion

o 0.6% pts who undergo coronary angiography die due to procedure (CT and MR may take its place in the future)

o LAD (L anterior descending) – supplies the LV (“widow maker”) – m/c in MI

▪ 70% reduction of vessel before angina symptoms

o Done prior to angioplasty (balloon – compress plaque; lasers)

▪ Atherosclerosis is a systemic disorder!!!

▪ Dr. Ornish: said atherosclerosis is reversible based on lifestyle changes

• Cardiomegaly: heart size > .55 (PA chest on fill inspiration – cross diaphragm at 10th rib)

o Causes: CAD, HTN, Dx

o Msr: midline to each side heart shadow ( add the #’s ( should be < half the thoracic msr??:??

o Work up: ecocardiography, US, stress EKG

o LV contracts – 2/3 blood in chamber pushed out (declines w/ age)

o Ischemia/hypoxia w/ ↓ Cardiac output (decline 1%/yr beginning at age 19)

• Respiration: affect on PA chest film view (Insp vs Exp)

o Heart size ↑ by as much as 20% on expiration and diaphragm goes up

o Chronic respiratory insufficiency – obesity ( ventilation reduces because diaphragm can’t go down

• Cor pulmonale

o Capillary vascularity of lung is atrophied due to emphysema, etc (R atrial and R ventral atrophy)

o Will eventually cause L sided heart failure (hypertrophy)

• Atrial myxoma: M/C tumor of the heart

o Tumor flaps between the L atrium and L ventricle

▪ R side heart will enlarge

• Fibrotic lung disease

o Pronounced pulmonary arteries (pulmonary artery HTN)

o In young individual (Cystic Fibrosis)

o Capillary atrophy resulting in fibrosis

o Retrosternal air space ↑ as w/ emphysema & diaphragm arc flattening

• HTN: affect on the heart

o Rounding below the diaphragm of the LV

o Prominence of the aortic arch (↑ pressure)

o Common cause of heart disease

o Hypertrophy then dilation of LV (↓ ability to contract as it dilates/stretches)

• CHF (congestive heart failure)

o Cardiothoracic ratio > 55%

o Jugular venous distention, pulmonary edema (alveolar spaces filled w/ exudates – leakage of the vessels) ( Rales are a sign of this

o Pre-cordial Heaving: heart is rolling and contacts chest wall

o Peripheral edema

o Nocturnal Paroxysmal dyspnea (violent coughing and SOB especially during sleeping) – prop up on pillows

o ↓ Cardiac output – MI due to ischemia

• Pectus Excavatum – sternum is concave ( pushes the heart to the left (don’t see R heart shadow

o Severe and no thoracic curvature = Straight back syndrome (heart trapped btn the sternum and vertebral column

▪ Cause heart murmurs

• Ventricular Aneurysm:

o Acute MI: damage mm results in expansion of the LV

o Rupture is fatal

o Calcification w/in structure (LV) – due to ischemia

• Calcification of mitral valve (also aortic)

o Insufficiency or stenosis

o Cause of calcification w/in the heart

o LV out on thoracic wall!!

o Tortuous aorta (↑ in size) – compensation for the calcification

• Atelectasis (indirect sign)

o Mediastinal or tracheal deviation

o Diaphragm elevation

o Hilar elevated

o Depressed intercostals narrowing

o consolidation

• Direct sign of atelectasis

o Right and left long fissures may be displaced

o Fissures not where they should be

• Silhouette sign

o In the lung

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