GI/ Abdomen and CNS/Head Radiology Flashcards
epidural hematomas are typically caused by what mechanism?
- blunt trauma (ie. MVA)
- Almost always (more than 90%) have an associated skull fracture
etiologies of dementia
- Vascular disease (e.g., multiple-infarct dementia)
- Alzheimer’s dementia
- Parkinson’s disease
- Normal pressure hydrocephalus (NPH)
- HIV encephalopathy
- Frontal lobe space occupying lesion (e.g., neoplasm, subdural hematoma)
*Brain MRI can be useful in diagnosing treatable conditions
what can free air in the abdomen be?
alway abnormal
- perforation, postop/postprocedureal
- pneumoperitoneum
what are the indications for an Upper GI fluoroscopy study? and what pathology can it detect?
Indication: epigastric pain, hematemesis, N/V, guiac positive stools, child with bilious emesis (malrotation)
Pathology: neoplasm, gastritis/duodenitis, gastric or duodenal ulcers, diverticulae, benign tumors, malrotation/volvulus
what is the test of choice for abdominal pain
Abdominal CT
*unless Gallbladder disease is suspected
what is a subdural hematoma
- hemorrhage into potential space btwn arachnoid and dura mater
- presentation w/in 48 hrs (HA, confusion, progressive dysfxn)
- high mortality rate
- tearing of the bridging veins between dural sinus and brain
what imaging would you order if someone presents with:
-Multiple sclerosis
MRI w/ Gad
Subdural Hematoma CT findings
- Acute: High-density (i.e. lighter on CT image), CRESCENT-SHAPED mass
- Subacute: “Isodense” (same density as brain)
- Chronic: Low-density (darker on CT than brain)
- possible midline shift
- distortion of Lateral ventricle
what is mass effect?
is the bowel displaced by a mass or enlarged solid organ?
what are 9 indications for abdominal U/s?
- Biliary Disease (Most common: Acute cholecystitis): Preferred modality
- Trauma Screening
- Solid Organ Lesion
- Evaluation (Cyst vs Solid)
- Appendicitis in children and pregnant women
- Vascular flow evaluation (Doppler)
- Abdominal aortic aneurysm
- Guided biopsy, ascites tap
- Pregnancy and disorders of female pelvis
what are types of nuclear medicine scans of the abdomen and what do they evaluate for?
HIDA – cholecystitis, biliary atresia, other suspected biliary disease
Tagged RBC scan – source of GI bleed
Sulfur colloid scan – evaluate liver, spleen
what imaging could you obtain for Vertigo?
- No imaging: most cases of vertigo
- Noncontrast brain CT: consider if there is CONDUCTIVE hearing loss and vertigo, not responsive to treatment
- Brain MRI: if there is SENSORINEURAL hearing loss, suspected acoustic neuroma or posterior fossa lesion
what are your imaging options for a seizure
MRI for the following:
- Healthy with new onset
- Alcoholic with new onset
- Epilepsy with poor therapeutic response
- Focal neurologic deficit
- Abnormal EEG
- non-contrasted CT used w/ trauma
what are the 3 main types of intracranial hemorrhages
- Epidural hematoma
- Subdural hematoma
- Subarachnoid hemorrhage
what bones can you see on an abdominal plain film? and what do you assess for?
- spine
- pelvis
- ribs
- prox. femora, hips
-fxs, bony erosions, degenerative changes
how do you assess calcifications on an abdomen plain film
- location
- shape:
- Round lucent center = phlebolith (calcified venous thrombi)
- Branching (staghorn) = renal
- Round and in RLQ…think appendicolith
what is a bulge in disc disease?
- diffuse enlargement of disc area
- Very common
*Usually not clinically important
May contribute to spinal stenosis
what is a benefit of an ERCP study?
treatment can be performed simultaneously:
- sphincterotomy
- stent placement
- dilation of strictures
- stone removal
what imaging is most sensitive in detecting early ischemic stroke?
MRI (more so than CT)
what organs can you see on an abdomen plain film?
- liver- location can often be estimated by location of ascending colon (difficult to assess heptomegaly)
- spleen- hard to visualize
- bladder- hard to visualize
- kidneys- Perirenal fat usually outlines kidneys, making them visible on plain film. (Appear to sit atop psoas muscles)
site of dilated loops in LUQ can possible be caused by:
pancreatitis
why is a waters’ view angle used for plain film?
-better see the maxillary sinus
What initial imaging study you would you obtain for:
-TIA or acute stroke
- CT initially to distinguish ischemic from hemorrhagic
- MRI (more sensitive) to follow
what is a protrusion in disc disease?
- nucleus pulposis pushes focally through fibers of annulus fibrosis
- Base wider than apex**
- May focally impinge on nerve or thecal sac
what contrast is used in PET scans of the head?
radiolabeled glucose (F-18-FDG)
site of dilated loops in mid-abdomen can possible be caused by:
ulcer, renal stone
wht is the most common cause of small bowel obstruction
post-surgical adhensions
what is the contrast material used for a GI fluoroscopy studies?
barium (or iodine w/ ERCP)
what is fluoroscopy and when is it typically used?
- Real time images produced by mobile table producing x-rays and converting images into video
- For GI studies, barium is used as a contrast material
- Very active examination (think about the patient’s condition and ability to cooperate)
- Significant radiation dose
what gases can you see in the colon on plain film
- Almost always air in the rectum or sigmoid colon
- Usually no air-fluid levels
- Stool shows multiple small gas bubbles
- greater than 6 cm colon, greater than 8 cm cecum = Abnormal
indications for a MRI w/ a HA
- Thunderclap headache (CT if unstable)
- Headache that:
- worsens with exertion
- is associated with a decrease in alertness
- is positionally related
- awakens one from sleep
- changes in pattern over time - New HA in HIV positive individual
- HA with papilledema
- HA with focal neurologic deficit
- HA with mental status changes
*CT is acceptable if MRI contraindicated or unavailable
when would you order an non-contrast abdominal CT
- Kidney Stones
- Retroperitoneal bleed
- Contrast Allergy
- Acute Renal Failure
- Cr less than or equal to 1.5 concerning
- Diabetes
what 3 questions do you need to ask when assessing bowel obstruction on a plain film?
- Is there air in the rectum or sigmoid?
- Are there dilated loops of small bowel?
- Are there dilated loops of large bowel?
How can you get a plain film to assess GI/abdomen and when would you get those?
- Supine abdomen: Inappropriately called a KUB (kidney, ureters, bladder)
- Upright abdomen: better-Ability to assess for pneumoperitoneum (free air)
- 3-way: best- Upright chest, upright abdomen, supine abdomen (Requires a somewhat mobile patient)
subdural hematomas are typically caused by what mechanism?
- Deceleration injuries (ie. MVA)
- falls in elderly
- *more common than epidural hematoma
Common indications for plain film of skull
- Evaluation of penetrating injuries
- Location of foreign bodies
- Evaluate for the presence of depressed skull fragments
- Quick screening test for spinal trauma
- Evaluation of the pituitary fossa.
- Waters’ view still used in some settings for sinus evaluation
*largely replaced by CT and MRI
indications for an AP and lateral plain film for the spine
- Spondylolisthesis
- Compression fracture
- Sacroiliac (SI) joint disease
- Disc degeneration
- Facet arthritis
- Tumor
- Infection in disc space
how can clinical findings help differentiate localized ileus vs early SBO (sx 1-2 days) or partial SBO
-Early (symptoms of a day or two) or partial SBO will typically present with obstructive symptoms
- Localized ileus will typically present with signs/
symptoms of the underlying process (e.g. pancreatitis,
appendicitis, cholecystitis, etc.)
site of dilated loops in RUQ can possible be caused by:
cholecystitis
what contrast is typically used for MRI
gadolinium based
when treating low back pain, what should you recommend inregards to bed rest?
No more than 48 hrs
Complications of angiography
- Reversible neurologic deficit (TIA, RIND) 2-3%
- Permanent neurologic deficit (infarct) 0-5%
- Arterial occlusion 0-0.4%
- Arteriovenous fistula/pseudoaneurysm 0-0.22%
- Contrast media associated nephrotoxicity 0-0.15%
when do you see portal venous air
- severe GI inflammation
- ischemia
subarachnoid hemorrhages are typically caused by what mechanism?
- ruptured aneurysm (berry)
- trauma
- arteriovenous malformation (AVM)
PET scan of the brain allows for evaluation of what?
functional evaluation of the brain
- metabolism
- blood flow
- electrical activity
- neurochemisty
indications for imaging for back pain
- Conservative treatment for 6 weeks first unless there are “red flags”
1. Immediate imaging is recommended in patients with acute low back pain who have major risk factors for: - Cancer (unintentional weight loss, Immunosuppression, history of cancer)
- risk factors for spinal infection (intravenous drug use, steroid use)
- risk factors for or signs of cauda equina syndrome
- trauma history (esp with hx of Osteoporosis, or age greater than 50)
- severe or progressive neurologic deficits (Radiculopathy).
what is a functional ileus on plain film
One or more loops of bowel lose their ability to propagate peristaltic waves, causing
a functional “obstruction” proximally, seen as gas-filled loops of bowel
what is an ERCP?
- Combines endoscopy and fluoroscopy
- Endoscopically-guided cannula is inserted through the Ampulla of Vater and contrast is injected into the bile ducts and/or pancreatic duct
how do you differentiate the colon vs small bowel on plain film?
- Colon is peripherally positioned and has HAUSTRATIONS,
folds usually don’t go all the way across the lumen and
are more widely spaced
- Small bowel is centrally positioned VALVULAE CONNIVENTES, folds traverse entire width of lumen
what are the indications for an esophgram (fluoroscopy study)? and what pathology can it detect?
Indications: dysphagia, odynophagia, reflux (may be reasonable alternative to EGD- sedation, expensive, greater risks)
Pathology: Reflux (common), hiatal hernia (common), aspiration, esophageal diverticulae, neoplasm, esophagitis
what sinuses and landmarks can you see on a PA view of a plain film of skull
- Sphenoid sinus
- Maxillary sinus
- mastoid air cells
- hard plate
- nasal septum