Radiology Exam 2

abdomen imaging

x-ray- pain, acute series, gas pattern, organs

CT- trauma, evaluate multiple organ systems simultaneously

US- gallbladder and biliary tree, female pelvis, AAA screening, POCUS trauma assessment

MRI- difficult diagnoses

acute abdominal series

supine abdomen/KUB/scout - bowel gas pattern, calcifications, masses

upright abdomen - free air, air-fluid levels

upright chest - free air, pneumonia, pleural effusions

normal gas patterns

air in stomach, 2-3 loops of air in non-dilated small bowel, air in rectosigmoid, no free air in diaphram, liver displaces gas, no fluid or dilation of colon

colon

normally distended bowel loops, air fills lumen completely, haustra visible

small intestine

located centrally, valvulae markings extend across lumen from one wall to another

extraluminal air

air outside bowel lumen, can be intraperitoneal, extraperitoneal, in bowel wall (pneumatosis intestinalis), in biliary system (pneumobilia)

intraperitoneal air (pneumoperitoneum)

air in peritoneal cavity, caused by rupture of an air-containing loop of bowel, trauma, or abdominal surgery (5-7 days post op)

1. air beneath diaphragm

2. rigler sign- visualization of both sides of bowel wall

3. visualization of falciform ligament

extraperitoneal air

air outside peritoneal cavity, same causes as intraperitoneal air

mostly seen on CT

streaky, linear appearance outlining extraperionteal structures, mottled blotchy appearance, relatively fixed position

hepatomegaly

enlarged liver, displacement of all bowel from RUQ down to iliac crest and across midline

splenomegaly

enlarged spleen, projects well below 12th posterior rib

enlarged kidney

extremely enlarged organ or large masses, large cyst compressing and displacing other organs

enlarged bladder

usually appears at soft tissue mass, displacing bowel

rim-like calcification

calcification of the wall of a hollow organ

linear/track-like calcifications

calcification in the walls of tubular structures

ex. arteries, ureters, fallopian tubes, vas deferens

walls of veins do not calcify

phleboliths

small blood clots in a vein that calcify over time, usually incidental finding, lucent centers

lamellar/laminar calcifications

calcification that forms inside a hollow (usually fluid-containing) lumen

cloudlike amorphous/popcorn calcification

calcification inside a solid organ or tumor

esophagus

best assessed by upper endoscopy, barium swallow, or gastrofin swallow

Z line- sometimes visible, junction between mucosa of esophagus and stomach

Zenker diverticulum

abnormal "pouch", food can get caught causing dysphagia

esophageal strictures

narrowing of the esophagus

superior- scarring from suicide attempts, lye or corrosive material swallowed, smooth appearance

middle and inferior- scarring from GERD, neoplasm

esophageal carcinoma

irregular column of barium entering stomach with peak like projections of barium -> concerning for malignancy

stomach

upper endoscopy is visualization of choice, abdominal CT imaging, barium upper GI no longer recommended

liver

xray- only shows organomegaly

CT- most common method for imaging

ultrasounds- detecting size and ascites

MRI- define tumors

fatty liver

focal or diffuse fatty infiltration appears as less dense on CT

liver trauma

most injured intra-abdominal organ, lacerations and hemorrhages often seen

hemangioma

most common benign hepatic tumor, often found incidentally on US and CT, looks like normal liver with contrast

hepatoma

most common primary malignant hepatic tumor

hepatic cysts

common, usually incidental findings, lower density than liver, clearly defineed

hepatic abscess

localized collection of pus, low density lesion

gallbladder and biliary tree

xray- radiopaque gallstones

US- diagnostic study of choice, abstain from food 6 hrs before

CT- less sensitive than US in detecting gallstones, good for difficult anatomy, masses, extent of disease

HIDA scan- nuclear medicine, visualizes flow of bile

cholelithiasis

stones in the gallbladder, often asymptomatic, classic biliary pain characterized by infrequent episodes of steady severe pain in epigastrium or RUQ with radiation to R scapula

echogenic stones, posterior acoustic shadowing

cholecystitis

inflammation of the gallbladder, usually caused by gallstone blocking outflow of bile through bile duct

-cystic duct most commonly obstructed

biliary sludge

aggregation that may contain cholesterol crystals, bilirubin, glycoprotein, often associated with biliary stasis

echogenic in gallbladder lumen, no acoustical shadowing

cholecystitis imaging

US- used most commonly, not best option

HIDA scan- useful for obstructed biliary duct, 96% sensitivity 90% specificity

MRI- 88% sensitivity 89% specificity

CT- may show perf or gangrene

pancreatitis

inflammation of pancreas, often related to biliary tract disease or alcohol intake

Sx: abrupt onset deep epigastric pain w/ radiation to back, N/V, sweating, weakness, abdominal tenderness and distention, fever

Labs: leukocytosis, increased serum amylase, increased serum lipase

pancreas imaging

xray- may show calcified gallstones, localized ileus

US- not helpful in acute pancreatitis, may identify gallstones

CT- differentiating pancreatitis from other possibilities, enlarged pancreas

pancreatitis imaging

may appear enlarged and irregular, infiltration of peripancreatic fat, fluid surrounding

spleen

most highly vascular organ, most injured organ in blunt trauma

CT is diagnostic study of choice

Tx: mostly non-surgical

splenic laceration

hemorrhage and hematoma present, dark fluid is blood surrounding spleen

ileus

paralysis of smooth muscle of intestines, inability of intestinal wall to perform peristalsis, bowel sounds decreased or absent

bowel obstruction

mechanical or functional obstruction of small intestine or colon

transition point- site of obstruction, high-pitched hyperactive bowel sounds

- bowel loops proximal to transition point dilate with air, secrete fluid

localized ileus

local irritation of 1 or more loops of a bowel secondary to inflammation of an adjacent visceral organ, "sentinel loops", loops lose normal fxn and become aperistaltic

CT scan shows cause

generalized adynamic ileus

entire bowel is aperistaltic, swallowed air dilates and fluid fills most loops of both small and large bowel

on imaging entire bowel is air-containing and dilated, air fluid levels, gas in rectum or sigmoid

bowel obstructions

small vs large bowel, causes differ based on bowel type

XRAY can be helpful

CT is most sensitive study for diagnosing site and cause

- oral contrast helps identify dilated loops -> do not use if large bowel obstruction suspected

- IV contrast helps detect complications of bowel obstruction

small bowel obstruction

lesion obstructs lumen, proximal to transition point bowel loops become dilated with air, distal to transition point bowel loops become decompressed, no air in rectosigmoid

causes: post-op adhesions, malignancy, hernia, gallstone ileus, intussusception, IBD

SBO imaging

X-Ray shows multiple dilated bowel loops, "step ladder appearance", no or little gas in colon/rectum

CT shows transition point, small-bowel feces sign (proximal to transition intestinal debris and fluid accumulate

Large bowel obstruction

lesion obstructs lumen of the large bowel, proximal to transition point large bowel dilates, distal to transition point peristalsis continues, emptying colon

Causes: tumor, hernia, volvulus, diverticulitis, intussusception

sigmoid volvulus

dilated sigmoid colon, air and stool in more proximal descending colon

can lead to strangulation (vascular compromise leading to infarction of bowel wall)

constipation

air in distal rectum, no bowel obstruction present

appendicitis

obstruction of appendix by a fecalith, inflammation, foreign body, or neoplasm -> leads to increased intraluminal pressure, venous congestion, infection and thrombosis of intramural vesses

S/Sx: vague pain, pain shift to RLQ, N/V, low fever

appendicitis imaging

CT- diagnostic study of choice in adults, dilated appendix that does not fill w oral contrast, periappendiceal inflammation, increased contrast enhancement of wall, perforation

US- diagnostic study of choice in pediatric pts

appendix

can be seen where it joins cecum, often not seen on CT

diverticulosis

outpouchings of colon, uncertain etiology, 90% pts asymptomatic, some pts have chronic constipation, abdominal pain, fluctuating bowel habits

diverticulosis CT

air filled outpouchings of colon that represent diverticula

diverticulitis

macroscopic inflammation of a diverticulum, may lead to microperforation, abscess, or peritonitis

S/Sx: aching LLQ pain, N/V, constipation or loose stools

Abdominal CT + f/u Colonoscopy or CT colonography

renal imaging

xray (IV pyelography)- mainly replaced by US and CT

US- size, symmetry, lesions, kidney stones, obstructions, hydronephrosis

CT- characterize US abnormalities, study of choice for nephrolithiasis, trauma

MRI- renal cell cancer, mass

renal calculi

stone in R ureter, stone in L kidney

bladder imaging

X-ray- only enlargement

Ultrasound- asses wall thickness, tumors, stones, diverticula, estimate post-void volume

CT- characterize bladder cancer metastases and local disease

Cystoscopy- visualize bladder

scrotal ultrasound

1st line imaging for acute causes of scrotal pain, Color doppler US is used in assessment of suspected torsion

female pelvic organs

US- imaging study of choice in mass or pain, transabdominal or transvaginal

CT- assists in localizing masses and surrounding structures

uterine leiomyomas (fibrosis)

benign smooth muscle tumors of uterus that occur in up to 50% of women >30, usually asymptomatic, can cause pain, pelvic US is imaging study of choice

Ovarian ultrasound

US is imaging study of choice for evaluating ovaries, cysts/tumors/torsion/PID

pregnancy

US is safe and reliable means of visualizing fetus

exclude ectopic pregnancy, estimate age, determine viability, number of embryos, estimate amniotic fluid vol, detect abnormalities, placental and fetal positioning, guidance for invasive studies

MSK imaging

Xray- study of choice for initial testing and most injuries

CT- complex fractures, preop planning, eval of soft tissue infections/masses

MRI- study of choice for soft tissue pathology and injury

Nuclear medicine bone scan- study of choice for detecting skeletal metastases

Ultrasound- soft tissue injury eval

osteoblastic diseases

increase bone density, seen as opaqueness (sclerosis), abnormal cortico-medullary junction, possible pathological fractures of long bone

ex. osteosarcoma, osteoblastic metastatic disease, avascular necrosis of bone, paget disease

osteosarcoma

most common primary bone malignancy, adolescents, tumor arising from osteoblastic connective tissue

osteoblastic metastatic disease

malignancy that has spread into the bone, lesions most often seen in vertebrae, ribs, pelvis, humeri, femora

radionuclide bone scan

metastatic disease involving nearly every bone in the axial skeleton

avascular necrosis

bone death due to lack of blood supply, often in proximal and distal femoral head, X-Ray is most used and MRI is most sensitive modality

caused by trauma, long term alcohol use, long term glucocorticoid use, sickle cell anemia, pediatric disorders

findings: devascularized bone becomes denser and more sclerotic

Paget's disease

focal disorder of bone metabolism, accelerated bone remodeling resulting in overgrowth, impairs integrity of affected bone, X-Ray and radionuclide bone scan

osteolytic diseases

decrease bone density, lower density of medullary cavity, accentuation of cortex, compression of vertebral bodies, pathologic fractures

ex. osteoporosis, hyperparathyroidism, osteolytic metastatic disease, multiple myeloma, osteomyelitis

osteoporosis

low bone mineral density, can be postmenopausal or aged related, risks include exogenous steroid administration/Cushing's disease, estrogen deficiency, inadequate physical activity, alcoholism

Dexa scan is imaging study of choice

hyperparathyroidism

excessive secretion of PTH, stimulating osteoclastic activity, calcium removed from bone and deposited in bloodstream -> hypercalcemia

- decrease in bone density

- subperiosteal bone resorption of fingers

- erosion of distal clavicles

- well-circumscribed lytic lesions in long bones called brown tumors

osteolytic metastatic disease

malignancy spread causes bone destruction, mainly medullary cavity but cortex can be involved

MRI- excellent at demonstrating status of the medullary cavity

- irregularly shaped, lucent bone lesions

pedicle sign

osteolytic metastatic disease destroys pedicles because of their blood supply

multiple myeloma

malignancy of bone in adults

solitary plasmacytoma- often seen as a soap-bubbly, expansile lesion in spine or pelvis

punched out lytic lesions- throughout axial and proximal appendicular skeleton

osteomyelitis

focal destruction of bone by blood-borne infectious agent (s. aureus)

xray- initial study, can take up to 10 days to display first findings

MRI- most widely used

radionuclide bone scan- higher sensitivity than MRI of approx 95%

- focal cortical bone destruction

- periosteal new bone formation

- soft tissue swelling and focal osteoporosis

osteomyelitis MRI

infection of the bone and intervertebral discs

athritis

disease that affects a joint and bones on either side of the joint, joint space narrowing

conventional radiograph -> first study of choice

hypertrophic arthritis

bone formation at the site of involved joint

primary osteoarthritis- mechanical stress

secondary arthritis- trauma/infections/etc..

charcot arthopathy

- osteophyte formations

- subchondral sclerosis

- subchondral cysts

- narrowing of joint space

osteoarthritis

subchondral sclerosis, joint narrowing, osteophytes

secondary osteoarthritis

joint space barely visible , subchondral sclerosis, phleboliths, cysts

erosive arthritis

inflammation and growth of abnormal tissue between the bones of a joint (pannus formation), lytic lesions near joint, pannus acts like a mass of growing and enlarging synovial tissue

rheumatoid arthiritis, gout, psoriatic arthritis, ankylosing spondylitis

rheumatoid arthritis

autoimmune and inflammatory arthritis. located in proximal joints of hands and wrists, usually B/L

hands- erosions, ulnar deviation of fingers at MCPs, subluxation of MCPs, swan-neck and boutonniere deformities

wrist- erosions

larger joints usually show no erosions

swan-neck deformity

hyperextension of PIP and flexion of DIP, characteristic of rheumatoid arthritis

Boutonniere deformity

flexion contracture of a PIP joint, extension of a DIP joint, characteristic of rheumatoid arthritis

gout

inflammatory changes incited by deposition of calcium urate crystals in joint, most commonly metatarsal-phalangeal joint of great toe

- sharply marginated erosion w sclerotic border "rat bites"

- joint space narrowing

- tophi- collections of urate crystals

- olecranon bursitis

psoriatic arthritis

inflammatory arthritis associated with psoriasis, skin and nail changes along with joint changes, hands and feet usually

- juxtaarticular erosions

- enthesophytes -> bony proliferation at sites of tendon insertions

- pencil in cup deformity

- absence of osteoporosis

septic arthritis

synovial membrane infection from a wound infection or from direct contiguous extension from osteomyelitis adjacent to joint

- rapid destruction of articular cartilage

- usually monoarticular

- associated soft tissue swelling

- osteopenia from hyperemia of inflammation

spine imaging

xray- initially ordered

nuclear medicine bone scan- metastases

MRI- study of choice for spinal cord, intervertebral discs, compression of spinal nerves

CT- best for bony abnormalities, MRI contraindicated, non contrast for trauma

canadian C-spine rule

safely rule out cervical spine injury (CSI) in alert, stable trauma patients without the need to obtain radiographic images, more sensitive and specific than NEXUS, CT usually performed

cervical spine imaging

immobilize neck with C-collar

xray- lateral, spinal fracture/subluxation

CT- usually performed rather than xray, fractures

P.A.C.T.S.

AP spine view, look for:

pedicles: no erosion

alignment

count vertebral bodies

transverse processes

sacrum and SI joints

scottie dog

nose- transverse process

eye- pedicle

ear- superior articular facet

front leg- inferior articular facet

neck- pars interarticularis

degenerative disk disease

progressive loss of height of the intervertebral disk space

- disk space narrowing

- vertebral body changes

- vacuum disk phenomenon- appearance of air density in disk space

herniated disks

degeneration of outer annular fibers, caused by acute compression of nerve root

MRI is study of choice

compression fractures

collapse of vertebrae, usually secondary to osteoporosis, no neuro deficit, wedge-shaped deformity

CT- best at identifying

spinal stenosis

narrowing of the spinal canal or neural foramina, caused by soft tissue and bony abnormalities, congenital or acquired

MRI is study of choice

cauda equina syndrome

injury or herniated disk compresses cauda equina nerve roots, back pain, weakness, saddle anesthesia, incontinence

Tx- emergency surgical decompression

ankylosing spondylitis

chronic and progressive arthritis characterized by inflammation and eventual fusion of sacroiliac and spinal facet joints, involvement of paravertebral soft tissues, more common in young males

xray

- sacroiliitis: bony fusion or ankylosis of sacrum and ilium

- bamboo spine: ossification of outer fibers of annulus fibrosis