RADT 112 EXAM #3 - THEORY

What is a CONTRAST MEDIA

a special agent used to enhance soft tissue

Describe NEGATIVE contrast media

RADIOLUCENT

• LOW absorption of radiation

• LOW atomic number

• e.g. air / gases (fizzies)

Describe POSITIVE contrast media

RADIOPAQUE

• HIGH absorption of radiation

• HIGH atomic number

• e.g. barium

List the different types of POSITIVE contrast media

• barium sulfate

• iodinated media (ionic and nonionic) (water soluble)

• water-soluble iodine ingestible compound / gastrographin

Describe BARIUM SULFATE

• chemical formula = BaSO4

• atomic # 56

• an inert powder - main ingredient is salt of barium

• chalky

• no flavor (must be added)

• chemically pure - non toxic

• insoluble

What type of suspension do barium and water make when mixed?

colloidal suspension

• if powder is not mixing with water (insoluble) it would be flocculation

Thin barium is ….

one part barium and one part water

• 1:1

Thick barium is ….

3-4 parts barium and one part water

• 3:1

What is FLOCCULATION

barium clumping or coming out of suspension

• there are suspending agents added to avoid barium from settling

• there are stabilizing agents added to avoid this

What are the CONTRAINDICATIONS for BARIUM SULFATE

you don’t want barium in the peritoneum

• pre-surgical patients

• perforations

• obstruction

• some post-op (bariatric studies)

What are the INDICATIONS for IODINATED CONTRAST MEDIA

• patients who can’t tolerate barium

• pre or post-surgical procedures

• perforations

What are the CONTRAINDICATIONS for IODINATED CONTRAST MEDIA

• hypersensitivity to iodine

• younger patients

• dehydrated patients

Describe IODINATED CONTRAST

• positive contrast (radiopaque)

• water soluble

• ingestable

• can be ionic or nonionic

• costly, possible allergic reactions

What does a SINGLE CONTRAST study mean?

utilizes only POSITIVE contrast

• thin barium or gastrographin

• uses more barium, so increase KV

What does a DOUBLE CONTRAST study mean?

utilizes POSITIVE and NEGATIVE contrast

• thick barium and air (fizzies)

• uses less barium, so decrease KV

What is the purpose of FIZZIES (utilizing air)

shows mucosal lining of structures better

Describe AIR CONTRAST

• negative contrast (radiolucent)

• done through fizzies or room air

• used for UGI and BE

What is different about the image appearance on FLUORO monitor versus RADIOGRAPH

negative image

• radiodense / radiopaque = black

• radiolucent = white

What is the protocol for SEQUENCING multiple fluoro exams

• iodinated contrast studies FIRST (IVU and CT)

  • moves through venous system quickly

• make sure barium doesn’t superimpose any structures that need to be visualized later on (e.g. start with esophagram then go to UGI)

• barium enema FIRST when paired with other GI studies

What are the patient preparations for MODIFIED SWALLOW

none

What are the patient preparations for ESOPHAGRAM

none

What are the patient preparations for UGI

NPO after midnight

What are the patient preparations for SMALL BOWEL

NPO after midnight (cathartics optional)

What are the patient preparations for BARIUM ENEMA

• diet

• cathartics (saline laxatives)

• suppository

• cleansing enema

What are the CONTRAINDICATIONS to BARIUM ENEMA (the prep)

• gross bleeding

• severe diarrhea

• obstruction

• inflammatory lesions

What are the DISCHARGE instructions for barium studies

• patients should drink plenty of fluids specifically water

• remind patients that stool may be white or lighter color

• might get a little constipated, take mild laxative if needed

Describe the process of enema tip insertion

• pt is in sims position

• keep modesty in mind

• wear gloves

• lubricate tip

• pt deep breaths

What is the SIMS position (BE)

• pt on left side

• right leg flexed

What should the temperature of BARIUM be

room temperature

• water 85-90 degrees F

The enema bag should be hung on an IV pole no higher than _________ (BE)

24 inches

Describe a R/F room

• utilized for all GI trac contrast studies

• fluoroscopy tube under the table

What is the purpose of the LIVER

production of bile

• largest gland in the body

Describe the GALLBLADDER

• thin-walled musculomembranous sac found on visceral surface of right lobe of liver

• functions to store and concentrate bile

• evacuates bile when activated by cholecystokinin

What is the BILE ROUTE

• right and left hepatic duct →

• common hepatic duct →

• gallbladder →

• gallbladder contracts, bile comes out →

• cystic duct →

• common bile duct →

• pancreatic duct →

• sphincter of Oddi →

• duodenum

Describe GALLBLADDER location

varies with body habitus

• hypersthenic = up higher, lateral, more transverse

• hyposthenic/asthenic = more middle, inferior

Describe a PTC examination

postoperative (t-tube) cholangiography

• aka delayed cholangiography

• performed via t-shaped tube left in common hepatic and common bile ducts for postoperative drainage

Describe an ERCP

endoscopic retrograde cholangiopancreatography

• useful method when ducts are not dilated and ampulla is not obstructed

• performed by passing a fiber-optic endoscope through the mouth into the duodenum under fluoroscopy

What are the ACCESSORY GLANDS

• salivary glands

• liver

• gallbladder

• pancreas

What are the three primary functions of the DIGESTIVE SYSTEM

• ingestion/digestion

  • oral cavity

  • pharynx

  • esophagus

  • stomach

  • small intestine

• absorption

  • small intestine (and stomach)

• elimination

  • large intestine

What is PERISTALSIS

contraction waves by which the digestive tube propels contents toward the rectum

• 3-4 waves per minute in filled stomach

• average emptying time for stomach is 2-3 hours

• average transit time to ileocecal valve is 2-3 hours

What is the purpose of a VIDEO SWALLOW (pharyngogram)

to study the form and function of the pharynx and epiglottis

What is the purpose of a ESOPHAGRAM (barium swallow)

study the form and function of the pharynx and the esophagus

What is the purpose of a UPPER GI SERIES (UGI)

study the form and function of the distal esophagus, stomach and duodenum

What are the RADIOGRAPHER’S responsibilities during fluoro

• prepare the room

• prepare contrast media

• obtain clinical history

• explain procedure

• ask if patient followed prep

• introduce and assist radiologist

• assist patient

Describe a VIDEO SWALLOW (pharyngogram)

• pt presents with dysphagia (pain/difficulty swallowing) (usually done for stroke patients)

• different consistencies of barium from thin to thick utilized (all single contrast)

• no overheads

• scout film is lateral upper airway (soft tissue)

Describe a UPPER AIRWAY / SOFT TISSUE LAT (scout film for video swallow)

• CR to level of C6

• extend chin, shoulders down and back

• criteria →

  • proximal airway and esophagus region demonstrated

Describe an ESOPHAGRAM (barium swallow)

• pt may present with dysphagia, heartburn

• thin barium, usually can do double contrast

• overheads taken recumbent

Why are ESOPHAGRAM overheads done RECUMBENT

to visualize as much barium as possible in the esophagus, more normal flow of the peristalsis happening in the esophagus

What is ESOPHAGEAL REFLUX

stomach acids refluxing back up to esophagus, burning sensation

What is ESOPHAGEAL VARICES

enlarged veins around esophagus

What is the SCOUT film for an ESOPHAGRAM

soft tissue lateral or PA/AP chest

Describe an RAO ESOPHAGRAM scout

• done LPO if needed

• 35-40 degree oblique

• CR to T5-T6

• criteria →

  • esophagus midway between spine and heart

Describe a LATERAL ESOPHAGRAM scout

• true lateral

• CR to T5-T6

• criteria →

  • esophagus midway between spine and heart

  • arms not superimposing esophagus

What is the VALSALVA MANEUVER

pt takes in deep breath and holds breath in while bearing down as if trying to move the bowels

• other way is mueller maneuver

What are RUGAE

rough, curved, indented surface area (mucosal folds)

• double contrast is what helps to visualize this mucosal lining

What are the FUNCTIONS of the STOMACH

• storage area for food during part of digestion

• secretes acids, enzymes, and other chemicals to chemically break down food

• mechanically breaks down food by churning / peristalsis

What is CHYME

chemically and mechanically altered food that leaves stomach

Describe STOMACH orientation

• fundus = most posterior

• body = anterior/inferior to fundus

• pylorus = posterior/distal to body

Face up (AP/LPO), barium _____

UP, in the fundus

Face down (PA/RAO), barium ______

DOWN, in the body and pylorus

Where is the STOMACH located in an HYPERSTHENIC pt

anatomy is superior / lateral

• stomach is HIGH and TRANSVERSE

• duodenal bulb/GB is T11-T12 (bulb right to midline)

• large intestine is WIDELY DISTRIBUTED

Where is the STOMACH located in a STHENIC pt

• stomach is C-SHAPED (backwards C)

• duodenal bulb/GB is L1-L2 (bulb slightly to right of midline)

• large intestine → L colic flexure HIGH

Where is the STOMACH located in a HYPOSTHENIC/ASTHENIC pt

anatomy inferior/medial

• stomach is J-SHAPED and LOW

• duodenal bulb/GB is L3-L4 (bulb at midline)

• large intestine is LOW NEAR PELVIS

What is the SCOUT done for a UGI

a high KUB

Describe a UPPER GI/UGI procedure

• double contrast preferred (to see mucosal lining / rugae)

• distal esophagus, stomach and first part of the duodenum visualized

• done because of epigastric pain, vomitting, r/o of ulcers

What is GASTRITIS

inflammation of mucosal lining

What is a HIATAL HERNIA

part of the stomach goes through diaphragm and superior

Describe an RAO UPPER GI overhead

• CR to L1 for sthenic

• 40-70 oblique (HYPER gets 70, HYPO gets 40)

• Criteria →

  • duodenal bulb and c-loop in profile

Describe an LPO UPPER GI overhead

• CR to L1 for sthenic

• 30-60 oblique (HYPER gets 60, HYPO gets 30)

• Criteria →

  • duodenal bulb and c-loop in profile

Describe a RIGHT LATERAL UGI overhead

• done on RIGHT so pyloric canal is facing downward, making barium flow more towards duodenum and bulb

• CR to L1 for sthenic pts

• Criteria →

  • retrogastric space demonstrated

What is the QUADRANT LOCATION of SMALL INTESTINE

• duodenum = RUQ / LUQ

• jejunum = LUQ / LLQ

• ileum = RUQ / RLQ / LLQ

• ileocecal valve = RLQ

What are the DIFFERENCES between LARGE INTESTINE / SMALL INTESTINE anatomy

• internal diameter →

  • large intestine has wider diameter

  • large has taenae coli that looks like commas

• relative location →

  • colon surrounds outside area of abdomen

  • small intestine fills the middle

Describe the SMALL BOWEL SERIES

radiographic examination of the small intestine

• done single contrast / utilize thin barium

• scout radiograph KUB

• pt drinks about 16 ounces of barium (note time)

• 15-30 minute radiographs (first image higher KUB)

• waiting until the barium passes to the large intestine

Describe the PA SMALL BOWEL KUB’s

• 15-30 minute radiographs

• CR 2 inches above iliac crest for early films (CR at iliac crest for rest)

• hourly radiographs

• PA preferred for natural compression

• images annotated with time

• criteria →

  • jejunum has feathery appearance

What is ENTEROCLYSIS

• double contrast small bowel series

• pt had catheter or gets catheter installed (barium goes straight into small intestine)

Describe a BARIUM ENEMA (BE)

radiographic examination of the large intestine

• double contrast study using air and thick barium

• can also be done single contrast though

When pt is SUPINE, what is the AIR-BARIUM distribution in LARGE INTESTINE

• barium on ASCENDING / DESCENDING colon

• barium on SIDES, air CENTRALIZED

When pt is PRONE, what is the AIR-BARIUM distribution in LARGE INTESTINE

• barium on TRANSVERSE / SIGMOID colon

• barium CENTRALIZED, air on SIDES

What is the pt preparation for a BARIUM ENEMA

• dietary restrictions day/afternoon before

• bowel-cleansing cathartics

• NPO after midnight (8 hours min)

• no gum chewing / no smoking

• enema morning of exam

• suppository morning of exam

Describe the CATHARTICS for BARIUM ENEMA

a substance that produces frequent, soft or liquid bowel movements

• two types = irritant and saline

• contraindications →

  • gross bleeding

  • severe diarrhea

  • obstruction

  • inflammatory lesions

What are ways to reduce pt discomfort during BARIUM ENEMA

tell pt to …

• relax abdomen

• deep oral breathing

• communicate cramping so that filling may be stopped or slowed

Describe PA/AP BE overhead/scout

• CR to iliac crest

• Criteria →

  • large intestine demonstrated

  • double contrast PA air would be in ascending and descending

Describe RAO/LPO BE overhead

• both anterior or both posterior obliques must be performed

• 35-40 degrees R and L oblique

• CR to iliac crest and 1 inch lateral to elevated side of MSP

• Criteria →

  • RIGHT colic flexure well visualized

  • ASCENDING / RECTOSIGMOID colon open

  • entire large intestine demonstrated

Describe LAO/RPO BE overhead

• both anterior and posterior obliques must be performed

• 35-40 degrees R and L oblique

• CR to iliac crest and 1 inch lateral to elevated side of MSP

• Criteria →

  • LEFT colic flexure well visualized

  • DESCENDING colon open

  • entire large intestine demonstrated

Describe the AP/PA AXIAL SIGMOID BE overhead

• can be done AP/PA

• Prone / PA →

  • 30-40 CAUDAD

  • CR at level of ASIS / MSP

• Supine / AP →

  • 30-40 CEPHALIC

  • CR 2 inches below ASIS / MSP

• Criteria →

  • visualizes SIGMOID colon

Describe LATERAL RECTUM BE overhead

• can also be done VENTRAL DECUB

  • prone

  • horizontal beam

• 10 × 12 collimation

• CR level of ASIS and midaxillary plane

• Criteria →

  • RECTUM region demonstrated

  • technically rectosigmoid region demonstrated

Describe VENTRAL DECUB BE overhead

• done in place of lateral rectum

• only done with double contrast studies

• done ventral cause it builds elevation of rectum and allows for better visualization

• visualizes →

  • air-fluid levels

  • posterior wall of rectum with air

Describe RIGHT LATERAL DECUBITUS BE overhead

• CR at iliac crest

• ascending colon DOWN, descending colon UP

• barium on LATERAL WALL of ASCENDING colon, air on MEDIAL WALL of ASCENDING

• barium on MEDIAL WALL of DESCENDING colon, air on LATERAL WALL of DESCENDING

Describe LEFT LATERAL DECUBITUS BE overhead

• CR at iliac crest and aligned to MSP

• descending DOWN, ascending UP

• barium on LATERAL WALL of DESCENDING colon, air rising on MEDIAL WALL of DESCNEDING

• barium on MEDIAL WALL of ASCENDING colon, air rising on LATERAL WALL of ASCENDING

Describe the EVACUATIVE PROCTOGRAM (DEFECOGRAPHY) BE overhead

functional study of the anus and rectum during the evacuation and rest phases of defecation

• clinical indications →

  • rectoceles

  • rectal intussusception

  • prolapse of rectum