CONTRAST

&

PROTOCOLS

WW/WL

WW WL

ST 500 50

LIVER 150 50

LUNG 1500 -600

BONE 2000 500

BLOOD 50 50

SUBDURAL 250 50

BRAIN 100 35

CTA1 800 300

CTA2 600 50

CTA3 1200 200

Water = 0HU

Air = -1000HU

VITALS, LABS

Vitals• SBP 90-140

• DBP 60-90

• HR 60-100bpm (check for 15s then multiply by 4)

• POX ≥94-95% on room air

• RR 16-24

• Temp 98.6F (range 97-99F)

• BP for kids = 70 + (2 x age)

• Normal blood flow rate 0.5m/s

Vitals

• >100bpm=tachy

• <60=brady

• Temp >100.4F is abnormal

• Pulse pressure= SBP-DBP

– Normal 21-59

– ≤20 is narrowed (hypovolemia, septic shock, increased peripheral vasc resistance, increased ICP)

– ≥60 is widened (anemia, exercise, hyperthyroidism, aortic regurg, arteriovenous fistula, decreased SV)

• MAP=1/3 PP + DBP

1st trimester 2nd trimester 3rd trimester

HR 77 +/- 2 85 +/- 2 88 +/- 2

SBP 98 +/-2 91 +/- 2 95 +/- 2

DBP 53 +/- 2 49 +/- 2 50 +/- 2

Increased HR

Decreased DBP

No changes in RR

Pregnancy

Children

0-2mos 3mos-1yr 1-6yr 7-12yr 13-18yr

RR 44-48awake

33-39 asleep

30-44 awake

22-33asleep

24 +/- 3 19 +/- 2 17 +/- 3

HR 126 +/- 20 131 +/- 20 88 +/- 9 70 +/- 8 64 +/- 7

SBP 72 +/- 10 95 +/- 15 93 +/- 13 100 +/- 10 112 +/- 12

DBP 51+/- 9 53 +/- 10 55 +/- 10 63 +/- 10 67 +/- 10

Faster HR, Lower BP, Faster RR (esp when awake)

NORMAL

WBC 4.4-11.3 x 109 L

HGB Male: 13.3-17.7 mg/dL

Female: 11.7-15.7 mg/dL

HCT Male: 40-52%

Female: 35-47%

Platelets 150-400 x 109 L

PT 10-13 s

INR 0.9-1.2

PTT 25-36 s

ACT 150s

Thrombin time 18-25s

Bleeding time 2-9s

D-Dimer 0-230 DDU ng/mL

NORMAL

Glucose 74-106 mg/dL

Cr Male: 0.7-1.2 mg/dL

Female: 0.5-0.9 mg/dL

Na+ 133-145 mmol/L

K 3.5-5.1 mmol/L

Cl 98-107 mmol/L

CO2 22-29 mmol/L

Ca 8.6-10.2 mg/dL

Phos 2.7-4.5 mg/dL

Mg 1.7-2.55 mg/dL

CK 26-192 IU/L

CK-MB 0-3.77 ng/mL

Troponin 0-0.01 ng/mL (may be +ve with renal failure)

NORMAL

Tbili 1.0 mg/dL

Direct Bili 0.3 mg/dL

ALK 16-95 IU/L

LDH 88-196 IU/L

SGOT 22-47 IU/L

Alb 4.1-5.5 g/dL

TP 6.4-8.1 g/dL

PREGNANCY

Serum B-HCG Detects preg 11d after conception

Urine B-HCG Detects preg 12-14d after conception

B-HCG <5mlU/ml is negative for pregnancy>25mlU/ml is positive for pregnancy

B-HCG in preg Doubles every 72hrs; peaks at 8-11wks; then plateaus

TROPONINS

NORMAL <0.04 ng/ml

INDERMINATE 0.04-0.50 ng/ml

MYO INJURY >0.50 ng/ml

Troponin• Troponins: Troponin-C (not-specific), Troponin-I (normal <10ug/L) and

Troponin-T (normal <0.1ug/L)

• Troponins released within 2-4hrs of acute myocyte injury and persist up to 7d

• CK-MB (creatinine kinase) or CPK-2 if elevated and ratio of total CK to CK-MB of >2.5-3.0 suggest CK elevation due to heart damage rather than skeletal muscle

BNP for HF

• BNP <100ng/ml (98% NPV for CHF)

• BNP >400ng/ml suggests acute CHF

GFReGFR Renal function

>89 Normal

60-89 Mildly reduced

30-59 Moderately reduced

15-29 Severely reduced

<15 Renal failure

eGFR is normalized to BSA and by sex/age/race=black vs non-black.

If black, multiply by 1.2

Contrast basics

Contrast types

• Iodinated– Ionic (no longer used)– Non-ionic

• Low osmolar– Monomers

» Isovue-370 (used at DGMC)--1.6cc/kg (max 140cc)

» Omnipaque-350 (used at DGMC)– Dimers (less osmolar than monomers)

» Ultravist-300 » Visipaque (iso-osmolar)--1.9cc/kg (max 140cc), goal=600mg Iodine

– Isovue M (from myelogram)• Hi osmolar

– Conray (IVP)– Cystoconray II (VCUG)

Common used contrast media

Iopamidol=Isovue

Iohexol=Omnipaque

Ioversol=Optiray

Iopromide=Ultravist (dimer)

Iodixanol=Visipaque (dimer)

Contrast types

• GI– Barium

• EZ Paque (“thin barium” for SBFT and single contrast UGI; keep refrigerated)• EZ HD (“thick barium” for double contrast UGI; add 50cc water)• EnteroH (for Enteroclysis along w/ methylcellulose “Entrocel”)• Liquid Polibar Plus (BE)• Readi-Cat II (diluted barium for CT scan; 2.1% w/v) for patient with allergy to iodine!!

– Gastrografin/Gastroview (water-soluble ionic)• HOCM (diatrizoate like Hypaque/Gatroview/Gastrografin)• LOCM (iohexol or Omipaque)—less aspiration risk, also use if pt has contrast rxn, poorly

absorbed by GI tract, has neutral taste (FDA approved for oral use)• 1% (CT)need to dilute for CT• 37% (Fluoro)use un-diluted for Fluoro• EZ Paste (esophagus CT)

– Other• Omnipaque 350 (water-soluble non-ionic LOCM) for patients with aspiration risk!! • EZ-Gas II (effervescent granules)• Bar-Test (13mm barium pill)

• Sinograffin (HSG)• Gadolinium (MRI)

Gastrografin vs Gastroview

• Gastroview (Mallinckrodt)– Diatrizoate Meglumine and Diatrizoate Sodium solution– Water soluble Ionic HOCM iodinated contrast– 30cc bottle (single use): mix 30cc in 1L water– Lemon-vanilla flavored– 367mg Iodine/cc (11g Iodine in 30cc bottle)– For oral and rectal contrast– Protect from light (store at room temp)

• Gastrografin (Bracco)– Similar to Gastroview– 370mg Iodine/cc (11g Iodine in 30cc bottle)

• Omnipaque 350 (for GI fluoro)– Water soluble Non-ionic LOCM iodinated contrast– Non-ionic (unlike Gastroview and Gastrografin)– Better taste– Omnipaque 350 (350mg Iodine/cc) for GI fluoro– Diluted Omnipaque 240 for peds and Omnipaque 240/300 for adults PO for CT scan: mix 50cc

in 1L of water

When to give PO water-soluble contrast instead of barium for GI fluoro

• PO water soluble contrast

– Gastroview

– Gastrograffin

– Omnipaque 350

• When to give

– Leak study (including fistulogram, sinus tract, abscess etc)—b/c barium can cause in mediastinitis and peritonitis

– Confirm percutaneous tube placement (like G-tube etc; if suspect NGT may be in lung give barium instead)

– SBO (therapeutic)not omnipaque

– Prior allergic-type rxn to barium (very rare)

– Peds fluoro studies

• When not to give

– High risk for aspiration (use Omnipaque 350 instead)

– Undiluted PO for CT scan (must dilute)

– Never give Gastroview or Gastrograffin IV

Omnipaque (iohexol) by GE• Intrathecal

– Omnipaque 180 (peds)

– Omnipaque 180/240/300 (adults)

– Note: Omnipaque 140 and 350 are not for intra-thecal use!

• IV (for CT)

– Omnipaque 240/300 (peds)

– Omnipaque 240/300/350 (adults)

• PO (for Fluoro)

– Omnipaque 350 (GI)

– Omnipaque 240/300/350 (arthrogram)

– Omnipaque 240/300 (HSG)

• PO (diluted for CT)

– Omnipaque 240/300 (peds CT)

– Omnipaque 300 (adults CT)

– 50cc in 1L of water drink 1cup every 20min starting 2hrs before (drink last cup right before scan)

Barium for CT scan• Readi-Cat 2

• 2.1% w/v (2.0% w/w)

• 450ml bottle (ready to drink; comes in different flavors)

• Shake well before use

• CT (SB) 30-60min protocol

– 1-2 bottles

– 30min protocol: 300cc 30min before125cc right before

– 60min protocol: 225cc 60min before225cc 30min before225 right before

• CT (SB+LB) 90min protocol

– 2 bottles

– 90min protocol: 450cc 90min before300cc 30min before150cc right before

Class % Iodine conc Iodine (mg/ml) Osmolality (mOsm/kg)

Visipaque-320 Non-ionic IV 32 320 290

Isovue-370 “ 37 370 796

Ultravist-300 “ 30 300 607

Gastrografin/Gastroview Ionic PO (HOCM) 36.7/36.7 367/367 1940/2000

Omnipaque-350 Non-ionic PO (LOCM) 35 350 844

Cysto-conray II Ionic urologic 8.1 81 400

Isovue-M 300 Intrathecal 30 300 616

Sinografin HSG 38 380

Barium sulfate % w/v

EZ paque Thin barium 45-65%

EZ HD Thick barium 250%

Liquid Polibar plus Barium enema 105%

EZ paste Esopho-cat 100%

Readi-cat 2 Barium for CT scan 2.1%

Bar-test 13mm pill

EZ Gas II Effervescent granules

Chemistry of iodinated contrast

• Parent molecule is benzene (toxic, water-insoluble liquid)

• Benzoic acid produced by adding acid gp at C position 1 (formation of salts or amides which influences water solubility)

• Use iodine for 3 main reasons: high contrast density, firm binding to benzene, low toxicity (addition of side chains at positions 3 and 5)

• All current contrast media is a chemical modification of 2,4,6-triiodinated benzene ring

• Characterized based on their physical and chemical characteristics (eg chem structure, osmolality, ionization, iodine content)

Chemical properties• Viscosity (thicker flows slower)

– Improves w/ keeping the contrast agent warm

• Osmolality (more molecules by kg of water)

– Particles or molecules (osmoles) per unit weight (kg) of water

– More similar the injected substance is to the osmolality of blood then the less fluid shift across the cellular space

– Higher osmolality means higher osmotic pressure

– Closer the osmolality of contrast agent is to body fluid, better the general tolerance (all non-ionic monomers are hyper-osmolar)

– Osmolality of blood and CSF is ~290mOsm/kg

• Iodine conc

– Given in mg/ml

– Strength of contrast agent is usually given as its Iodine conc

– Increasing strength means increasing opacifying power, but also increasing osmolality and viscosity and hence decreasing tolerance

Chemical properties

• Ionicity (+ve cations and -ve anions)

– Ionic contrast have higher osmolality

– One method of decreasing osmolality is to make a dimer

– Ionic and Non-ionic contrast media may be monomeric or dimeric

– Monomer contains one benzene ring and total of 3 iodine atoms

– Dimer contains 2 benzene rings and total of 6 iodine atoms

– Osmolality of a non-ionic agent is less than ½ of that of ionic agent

– HOCM has 5-8x osmolality of plasma

– LOCM has 2-3x osmolality of plasma

– Visipaque is an example of non-ionic dimer (iso-osmolar)

– Isoosmolar has same osmolality as blood/plasma/CSF

Contrast rxn

Contrast Rxn (review)

• Risk of death 1 in 100,000 risk of death

• Risk factor:

– prior contrast rxn (5-fold)

– asthmatic (atopy)

– renal/cardiovascular dz

• Warn patient about:

– Warmth, flushing

– metallic taste

– possible nausea

• Sneezing may be omnious sign of contrast rxn

• If history of contrast rxn:

– pretreat with meds (steroids/benadryl)

– use visipaque (iso-osmolar)

– if oral contrast needed, consider diluted omnipaque (low osmolar) instead of gastrograffin/gastroview (hi osmolar)

• Common rxn: vasovagal (hypotension+bradycardia)treat with leg elevation; IVF; 0.5mg Atropine IV slow

• Limit IV contrast to max 300cc/d

Contrast rxn (review)• Anaphylactic rxn

– MILD: HIVs

• HivesBenadryl 25-50mg IV/IM

• ItchingBenadryl 25-50mg IV/IM

• Vomiting

• Swelling (face/eyes)

– MOD: BLS

• Bronchospasm (wheezing/SOB/cough)10L/min oxygen; 2puffs albuterol; Epi pen or 0.3mg 1:1000 SQ/IM

• Arrhythmia

• Laryngeal edema (stridor/hoarseness/throat tightening)1mg 1:10,000 EPI IV

• Screwed up vitals (brady/tachy; hypo/hypertension)

– Hypotension+tachycardia (vascular collapse)1mg 1:10,000 EPI IV

– SEVERE: think CPR

• Cardiac arrest

• Respiratory arrest

• Seizure (neuro symptoms)5mg valium (diazepam) IV push

• Delayed rxn

– Within 1h to 7d

– Flu-like symptoms

– More common with non-ionic dimers like visipaque

• Risk of CIN: renal insufficiency

Incidence of contrast rxn

• HOCM 5-12%

– Anaphylactoid reactions more common

• LOCM 1-3%

– Cardiovascular decompensation (hemodynamic) more common

• Major life-threatening contrast rxn is rare

– ~0.04% to 0.004%

– Risk of death from contrast 1 in 100,000

Risk factors

• Age Infants and >60yo

• Sex F>M

• Medical conditions asthma (atopy), DM, renal/cardiac dz, dehydration

• Hematologic conditions polycythemia, myeloma, SS

• Meds (no consesus) NSAIDs, IL-2, beta-blockers

• Contrast related >20mg iodine, faster inj rates, intra-arterial inj, prior contrast rxn

• History prior contrast rxn (5-fold)

Prior contrast rxn (5x)

Allergy to shellfish or topical iodine is not a risk factor.

Patient with severe allergy to iodine, should avoid oral contrast as well.

Etiology of contrast rxn

• Anaphylactoid or idiosyncratic

– Exact etiology not well understood

– Symptoms similar to an allergic rxn (but not mediated by Ig-E pathway or antibody formation)

– Enzyme inductionvasoactive substances (histamine/serotonin)activation of complement pathyways

– More common in pts w/ asthma (atopic), prior rxn (4-6x), pre-existing renal/cardiovasc dz, on beta-blockers

– Usually begins w/in 20-30min of injection and independent of dose given

– MILD (rash, itching, nasal discharge, N/V)

– MOD (persistence of mild sxs, facial/laryngeal edema, bronchospasm, tachycardia or bradycardia)

– SEVERE (life-threatening arrhythmias, hypotension, overt bronchospasm, laryngeal edema, pulm edema, seizure, syncope, and death)

Etiology of contrast rxn• Non-anaphylactoid or chemotoxic

– Chemotoxic effect related to dose and chemical nature (osmolality, viscosity, hydrophilicity, etc)more likely debilitated or unstable pt

– Result of ability of contrast media to upset homeostasis (esp blood circulation)

– Depends on chemical properties of media (i.e ionicityions affect electrical activities of nervous and cardiac systems; osmolalityshifts in fluid volumes)

– Also, increasing iodine conc and volume increases these risks

– Examples

• Warmth, metallic taste, N/V

• Vasovagal

• Mild transient hypotension

• Nephropathy (CIN)

• Delayed rxns (>1hr)

Urticaria Anayphylactoid Initial size marking and f/u

Benadryl 25-50mg PO/IM/IV

Bronchospasm Anayphylactoid Pulse ox, HR, BP 6-10L/min O22-3puffs beta-agonist MDISecure airway1:1000 EPI SQ/IM (EpiPen 0.3mg; Epipen Jr 0.15mg)1cc 1:10,000 EPI slow IV if hypotension (repeat q5min)

Facial or laryngeal edema

Anaphylactoid Pulse ox, HR, BP Do not respond to inhaler (may makeit worse)o/w same as above

Hypotension and tachycardiac (fast pulse)

Anaphylactoid(vasodilation)

Pulse ox, HR, BP Elevate legs 60degRapid IVF6-10L/min O21cc 1:10,000 EPI slow IV (repeat q5min)

Hypotension and bradycardia (slow pulse)

Vasovagal Pulse ox, HR, BP Elevate legs 60degRapid IVF6-10L/min O20.5mg Atropine slow IV (repeat to total of 2-3mg or 0.04mg/kg)

Management (anaphylactoid)

Management (non-anaphylactoid)

Cardiac arrhythmia

Ionic abnl Pulse ox, HR, BP, EKG ACLS protocol

HTN Catecholamine release

Pulse ox, HR, BP, EKG 0.4mg NTG SL5mg Phentolamine IV for Pheo

Seizures Ionic abnl Pulse ox, HR, BP, EKG Secure airway6-10L/min O25mg Diazepam (Valium) IV/IM0.5-1mg Midazolam (Versed) IV15-18mg/kg Phenytoin (Dilantin) infusion at 50mg/min

Pulm edema Osmolar changes (fluid shifts)

Pulse ox, HR, BP, EKG 6-10L/min O220-40mg Furosemide (Lasix) IV slow1-3mg Morphine IVConsider steroids

EpiPen 0.3mg

1. Remove blue top (safety)

2. Hold it like a knife

3. Inject orange tip into (perpendicular to)

upper thigh (works thru clothes)

4. Hold for 10s

Delayed contrast rxn

• Btwn 1h to 7d after contrast inj

• 2%

• Common sxs

– Flu-like

– Less commonly joint pain, parotitis

• Delayed rxns more common in pts on IL-2 (chemo) and in those injected w/ non-ionic dimers

• Usually resolve spontaneously with supportive therapy

Can contrast rxn occur with oral iodinated contrast agents?

YES

•1-2% of iodinated CM get absorbed after PO/PR administration

•No contrast reaction with Barium (Readi-cat II)

•Less risk of contrast rxn with HOCM oral agents than IV agents because of dilution

•Less risk of contrast rxn with LOCM than HOCM oral agents

•Avoid oral contrast in patients with severe contrast allergies

Drugs

Emergency cart

Albuterol Beta-2 agonist 2puffs (may repeat) Avoid in laryngeal edema

Atropine Parasympatholytic agent 0.6-1.0mg IV slowMax dose=2mg

Min dose 0.6mg o/w paradox effect

Benadryl H-1 receptor site blocker 25-50mg IV or IM Does not counteract rxn that already begun

Epinephrine Sympathetic agonist IV PREFERRED1cc of 1:10,000 (0.1mg/cc)q5min slow (upto 1mg max)0.1cc of 1:1000 SC/IM

Useful for:-severe urticaria-facial/laryngeal edema

Alpha=peripheral vasocontrictorB-1=cardiacB-2=bronchodilation

SQ IF NOT IV0.1-0.3cc of 1:1000 (1mg/cc)

-bronchospasm-cardiovasc collapseCAUTION if HTN

Diazepam Benzodiazepine 5-10mg IV pushMax 30mg

For seizure

NTG Vasodilator 0.4mg SLMay repeat q5min (for a total of 3 doses)

Prep prior to contrast

IV contrast policy (KP)

• GFR ≥45 use full dose

• GFR 30-45 use 1/2 dose Visipaque

• GFR <30 no IV contrast

IV contrast prep

• Prefer NPO or just clear liquids x6hrs to avoid N/V

• 20G for all CT (except for PE or Aortic protocol, use 18G)

• Portocatheter access performed by oncologist

• 2 PICC are CT injectable: Morpheus and Purple Power

• 2 ports are CT injectable: Smart Port and Purple Power

• Need to know any contact or airborne precautions (TB, MRSA, HIV, Hepatitis)

• 1cc/lb or 2cc/kg for peds (use Visipaque)

IV contrast prep

• For DM, hold Glucophage/Metformin, Glucovance, Metaglip, Avandament day of study and for 48hrs after contrast admin (risk of lactic acidosis)

– Ordering physician to check Cr before re-starting

– Don’t need to stop for Gad

• Pregnancy statement for ages 12-55 (any chance you are preg? 1st day of Last LMP?) with signature

• For breastfeeding, pump and discard immed prior to and for 12hrs after study

– <1% of contrast excreted in milk

– <1% ingested by baby actually gets absorbed in baby’s GI tract

– Plasma T1/2 in ~2hrs (nearly all excreted w/in 24hrs)

• For Pheo, consider MRI or pretreat w/ Phentolamine (Regitine) 5mg (5cc) IV bolus (risk of HTN crisis)

– Phenoxybenzamine 10-20mg PO TID or QID x7-10days and 1hr prior to procedure

• Check Cr for DM, age>50yo, and all inpatients

• No longer screen for shell-fish allergy per ACR (no cross-reactivity)

• Allergy to topical iodine is not a risk factor

Metformin

IV contrast consent form• Personal hx of:

– Diabetes? Do you take Metformin/Glucophage, Glucovance, Metaglip, Avandament? When was the last dose?

– Heart disease or failure? Take Propranolol?

– Kidney disease or failure? On dialysis?

– Asthma? Controlled? How often use inhalers?

– Blood disease? What?

– Severe allergies? To what? Describe?

– Ever been injected with Xray contrast dye? Prior rxn? Describe?

– Any electronic devices implanted under skin? Where?

– List all meds and doses currently taking?

• Your health care provider has referred you to DI section for an exam that requires injection of contrast media into your blood vessels so that it would enhance appearance of structures in the body for accurate diagnosis.

• Common rxn are nausea or a warm, blush-like feeling.

• Occasionally, minor allergic rxn like hives, itching, sneezing, or localized swelling of eyes/lips may occur.

• More severe rxn such as difficulty breathing can occur rarely.

• Very rarely (less than 1 pt in 100,000) a contrast rxn can result in severe allergic rxn , which can lead to death.

• Your physician is aware of the remote possibility of complications and feels that the diagnostic information obtained by performing this examination outweighs the minimal risk involved.

Type of contrast media used Reaction Type

Amount of media usedcc

Comments

Lot # / Expiration Dates /

Tech Initials Supervising Radiologist

Premedication for contrast allergy• Start large bore IV

• Get consent form

• Ordering physician available

• Premedicate (oral steroids preferred over IV)

– Benadryl 50mg PO 1hr prior to study

– Prednisone 50mg PO 13h, 7h, 1h prior to study

– Other option: Methylprednisone (Medrol) 32mg PO 12h, 2h prior to study

• Emergent cases

– Benadryl 50mg IV/IM 1hr prior to study

– PO Methylprednisone (Medrol) 40mg IV q4h until study

– Other option: Hydrocortisone (or equivalent) 200mg IV q4hr until study (at least 6hrs)

• Use Visipaque (iso-osmolar non-ionic)use for all CT head/neck

• Use 70cc instead of 100cc

• Observe patient for at least 30min after study

Premedication peds (ACR)

CHCS order set (“contrast set”)

• PREDNISONE 50MG PO 13, 7 and 1 hr before procedure

• DIPHENHYDRAMINE (BENADRYL) 50MG PO one hour before procedure

Premedication for renal insuff

• Check Cr (within last 2 mos) for DM, age>50yo, and all inpatients

• Cr>1.5 is abnl (now we use GFR>45; no contrast if GFR<45)

• FOR Cr>2.0, avoid study (consider discussion w/ nephrologist for possible need for post-study dialysis)

• GFR

– >60 OK

– 45-60 Give Mucomyst; IV hydration; use Visipaque; reduce contrast dose

– <45 Don’t give IV contrast (do VQ instead)

• Cr clearance is more accurate measure of renal fxn (<50cc/min is abnl and <25cc/min is severe)

– http://www.chestx-ray.com/Practice/RenalInsuff.html

Premedication for renal insuff

• FOR Cr btwn 1.6-2.0

– Fluid hydration

• PREFER IV over ORAL hydration (Oral 2-3L in 12hrs prior to study)

• 1cc/kg/hr or 100cc/hr NS for 12hr prior and 12hr after study

• Some prefer isotonic solution with Bicarb (mix 150mEq sodium bicarb in 1L of sterile water or 3amps in 1L sterile water; 3ml/kg/hr IV 1hr prior to procedure then 1mg/kg/hr x6h after procedure)

– Mucomyst (N-acetyl-cysteine)

• Awful taste and smell

• Comes in 30cc vial of 20% (200mg/cc)—refrigerate the bottle

• 600mg (3cc) PO bid (a day before and the day of study starting right after contrast administration i.e. 2 doses before and 2 doses after study)

– 24hr and 12hr prior to study

– Immediately (within 1hr) after study

– Last dose 12hr after study

• 150mg/kg IV over ½ hour or 50mg/kg IV over 4hrs

CHCS order set (“mucomyst”)• ACETYLCYSTEINE 20% (MUCOMYST) 30ML TAKE 3 ML OF SOLUTION

(MIXED IN JUICE IF YOU WISH) BY MOUTH TWICE THE DAY PRIOR TO YOUR PROCEDURE, ALSO RIGHT AFTER PROCEDURE AND IN THE EVENING AFTER YOUR PROCEDURE

IV contrast in Pregnancy/Breastfeeding• IV contrast for CT should be avoided in pregnancy (although is safe)—avoid esp 1st trimester

• Believed to be extremely low passage of contrast to fetal circulation

• Possible neonatal hypothyroidism with ionic (not with non-ionic) contrast

• Screen neonate for hypothyroidism after birth (as is usually done)

• IV Gad for MRI is contra-indicated (category C by FDA)

• Steroids + benadryl premedication is OK

• Consent needed for perform MR if 1st trimester (avoid MRI in 1st trimester unless absolutely needed since risk of spontaneous abortion is high in 1st trimester and ppl may blame MRI for it)

• 10day rule: if more than 10d have past since 1st day of last menstural period, patient needs a pregnancy statement

• May cease breastfeeding for 24hrs after contrast (iodinated and Gad) administration (pump and dump)

– <1% of adm dose excreted into milk

– <1% of dose ingested by infant is absorbed from GI tract

– Hence, <0.01% of dose given to mom is actually absorbed by infant

– This is <1% of recc dose to infant undergoing imaging study (usually 2cc/kg)

CT in Pregnancy• Consent needed for all CT; and also 1st trimester MR

• Delay CT until after 1st trimester if possible

• CT head ok; limit CT chest to 2cm below dia; low dose tech for CT

• Use shield over gravid uterus (after scout is done)

• Organogenesis 2-15wks

• Teratogenesis (non-stochastic with threshold of 5rads or 50mSv)– Microcephaly, micro-opthalmia, MR, growth retardation, behavorial defects, cataracts

– Extremely unlikely before 2wks and after 15wks

• Carcinogenesis (stochastic effect)– Baseline relative risk of fatal childhood CA = 1 in 2000

– After 5rads relative risk of fatal childhood CA = 2 in 2000 (risks doubles)

• Pelvic CT in 1st trimester ~2.4rads

• Pelvic CT in 3rd trimester ~4.6rads

• Health Physicists to calculate and document fetal dose

• Pregnancy termination advisable for fetal dose >10rads or 100mSv (100mGy)

Pregnancy indications

• r/o stone: do u/s 1st (if neg, CT or MR)

• r/o appy: u/s or MR prior to CT for 1st or 2nd trimester (for >35wk, u/s not useful)

• r/o trauma: u/s may be considered if not serious injury, otherwise CT (MR generally not useful)

• r/o PE: CTA has less dose to fetus than VQ even if use half dose but CTA dose to breast is high (prefer to start with u/s DVT 1st)—limit CT to 2cm below dia

• Pelvimetry: low-dose CT

Complications after contrast injection

ExtravasationInitial therapy (up to 30ml ionic / 100ml non-ionic contrast) :

• Elevate the affected extremity above the heart

• Warm compress to aid in absorption (for 1-3 days)

• May alternate with ice pack for pain

• Close observation for 2-4 hours; monitoring for any complications (may worsen over 24-48hrs)

• Document: amount of contrast, location, redness (mark skin edges), firmness, temperature, distal sensation, distal pulses

• Assess for blistering; distal capillary refill; pain; changes in distal sensory (compartment syndrome and tissue necrosis)

• Squeeze fluid from puncture site (not effective); dry dressing; Silver Sulfadiazine if blisters

• Reschedule surgery

• Call referring physician for any extravasation over 5 ml

Immediate plastic surgery consultation for the following indications:

• Extravasation volume exceeding 30 ml of ionic or 100 ml of nonionic contrast material

• Skin blistering

• Altered tissue perfusion (decreased capillary refill over or distal to injection site)

• Increasing pain after 2-4 hours

• Change in sensation distal to extravasation site

• TX: drainage, liposuction, saline flush

Extravasation

Daily phone call by radiologist or nurse until symptoms resolve to assess for:

• residual pain blistering redness

• skin color change hardness

• increased or decreased temperature of skin at extravasation site

• change in sensation

Documentation: contrast material reaction form and/or incident report progress note (for medical record)

Letter for patient

Air embolism

• >50cc• Hypotension, hypoxemia, arrythymia, AMS, pulm

edema• Tx:

– Place pt in left lateral decub position– Administer 100% O2 (via non-rebreatheable mask @10L)– Consider hyperbaric therapy

Initial

3min

25min

AKIN criteria of contrast-induced nephropathy (CIN)

• Acute Kidney Injury Network (AKIN)

• Any one of following w/in 48hrs

– Increase in Cr ≥0.3

– Increase in Cr ≥50% (≥1.5 fold above baseline)

– Urine output reduction to ≤0.5cc/kg/hr for atleast 6hr

Contrast-induced Nephropathy (CIN)

• Check Cr if hx or DM or renal dz or >70yo• Cr btwn 1.5-1.9 pre-treat with mucomyst and bicarb and hydrate with

1/2NS 100cc/hr 12hr before and after procedure• Cr >2.0 avoid contrast study• Newer guidelines ask for eGFR• Remember for kids Cr should be in range of 0.2-1.0• Rise in serum creatinine

– >25% above baseline– an absolute rise of 0.5mg/dl (>44mmol/L)– w/in 48hrs (some say w/in 3days) after contrast administration

• Acute rise in serum creatinine w/in 24-48hrspeaks at 4-5daysreturns to baseline over 7-10days

• Usually non-oliguric• No contrast retension >24hrs• Enlarged kidneys with prolonged nephrograms w/o excretion >15min• Max 300cc (150cc in kids) IV contrast in 24hrs

Contrast-induced Nephropathy (CIN)

• Risk factors:– Raised serum Cr (>1.4) esp secondary to DM nephropathy– Dehydration– CHF– Age >70yo– Concurrent nephrotoxic drugs (eg NSAIDs, aminoglycosides like gentamycin etc)

• Avoidance:– Small amount of contrast material possible (rare with contrast <100cc)– D/C nephrotoxic drugs prior to procedure– IV hydration (PO 500cc prior and 2500cc first 24hrs; IV 100cc/hr NS hr prior to

procedure and continue first 24hrs)• Treatment

– Hydration (at least 100cc/hr PO or IV starting 4hrs before to 24hrs after)– Use low-dose of low-osmolar (ultravist) or if available, iso-osmolar (visipaque) contrast

media– Stop nephrotoxic drugs for at least 24hrs– DO NOT administer mannitol or diuretics (esp Lasix)– May need to treat w/ Vasodilators and Hemodialysis

*Protocol CT

IV access• Administration of IV contrast using a power injector should be through a ≥20G peripheral IV

access

– 18G preferred for CT Angiograms

– 18-20G: ≥3cc/s

– 22G : ≤3cc/s

– 24G: hand inj only

• Catheter other than peripheral IV which are acceptable for power injection:

– CT Injectable PICC, CVC and Ports may be used to inject IV contrast after aspirating and discarding blood from the line (confirm marking on hub of catheter for max rate and correct lumen to inject)

– Max adults: 5cc/s <300psi and Max peds: 2cc/s <300psi

– Can always hand inject a non-power CVC (except dialysis catheter—which we should never use)

– External Jugular (EJ) angiocath may be used with maximum injection rate of 2cc/s and 150 psi

– Do not use CVC cannula within IJ/EJ

– Lower extremity IV access (not for CTA) will be reviewed case by case basis by radiologist

IV access– PICC

• PowerPICC (purple) by BARD

• Cook Spectrum PICC (red)

• Navilyst PICC

• Morpheus Smart PICC by AngioDynamics

– PORT (must use Gripper plus Huber needle)

• Smart Port by AngioDynamics (distinctive scalloped shape)

• P.A.C. port by Smith Medical

• PowerPort by Bard (distinctive triangular shape)

– CVC (not dialysis catheter)

• ARROWgard Blue plus

• Power Hickman by Bard

• Power Hohn by Bard

– CVC cannula in IJ/EJ (do not use b/c risk of neck extravasation!!!)

– Dialysis catheter

• Do not use—only exception is Trialysis catheter by Bard (purple lumen) but approval of nephrologist is required!!

Dialysis catheter

• Dialysis catheter (like Permcath® etc) catheters being used for dialysis should not be used to administer IV contrast (require approval of nephrologist for hand injection)

• Exception: Trialysis catheter by Bard is approved for poer injection but Nephrologist approval is still required

• Line should be aspirated, to remove the heparin, prior to injecting NS or contrast

Implantable devices in CT• Given the potential for malfunction of implanted medical devices (cardioverter-defibrillators,

defibrillators, infusion pumps, neurostimulators, and pacemakers) in patients receiving high dose ionizing radiation through CT, the following will be the policy for handling patients who present for CT with implanted medical devices:

– 1) Implanted medical devices should be noted on preliminary CT scout.

– 2) If function is not necessary during the exam and the patient is able, have the patient turn the device off.

– 3) Move the device out of the field of scan if possible.

– 4) Use minimal radiation dose possible and avoid continuous scanning directly over the device.

– 5) If repeated direct exposure of the device necessary (such as in CT-guided biopsy, perfusion scans or cardiac imaging), prepare for possible device malfunction. For example, have a cardiologist present if a high dose CT will expose a cardiac pacer to extensive ionizing radiation.

– 6) After completion of the study, turn device back on (if it was turned off) and ensure it is functioning properly.

Contrast CT

• IV contrast– PE 8s delay (SMART PREP)– Aortic phase 25s delay– Arterial phase 35s delay– Portal venous phase 70s delay– Nephrographic phase 90-100s delay– Hepatic delay 3 or 5min and 10min– Pyelographic (excretory) phase 8-10min delay

ER ordering guide

(Dr George Buse)

CAP 100cc 2cc/s 80s

Neck + CAP 100cc 3cc/s N=45s CAP=35s after Neck

AP 100cc 2-3cc/s 70-80s

3p Liver 100cc 3cc/s Noncon Art=30-35s PV=70s 10min delayed (hemangioma/cholangCA)

2p Pancreatitis(water prep)

100cc 3-4cc/s Non-con Panc=40-45s

3p Panc mass(water prep)

100cc + 30cc NS flush

3-4cc/s Noncon Art=25-30s Panc=40-45s PV=70-75s(AP)

Adrenal 100cc 3cc/s Non-con Ven=60-70s Delay=15min

Renal mass 100cc 3cc/s Non-con(kidneys only)

CM=35s Nephr=70-95s Exc=10min(optional)

CT urography(hematuria)

70cc con +25cc NSwait 8-10min80cc con

2-3cc/s Non-con (AP)

Nephr=70-95s (breathing instructions)

Wait 8-10min, inject more contrast and then Excretory= 100s

Scout (IVP) optional

Trauma CAP 150cc(renal/DM pts: 100cc visipaque+50cc NS chaser)

3cc/s Non-con optional

Thoracic Aorta=smart prep desc ao(~30s)

Delayed AP=60s

16 Slice CT

Mesenteric ischemia 100cc 2-3cc/s 70-80s No PO contrastJust water prep

AAA 100cc 3cc/s Non-con Contrast=smart prep at T12

Dynamic chest 100cc 2cc/s 50s

PE Test: 20ccActual=80cc con + 30cc NS chaser

4cc/s (if 20G IV)5cc/s (if >20G IV)

Test injection (~14s)

Smart prep (150HU @MPA)

Runoff=2.5-3min (aortic bifur to knees)

Dissection 100cc 3cc/s Non-con CAP Contrast CAP=smart prep aorta at level of dia (~30s)

Cardiac Test=20cc con + 20cc NSActual=70-75cc + 40cc NS

5cc/s ROI over Left Main coronary

16 Slice CT

64-SLICE CT mAs Slice Pitch Contrast Rate/Delay Other

CT head w/ow/ 2.0cc/4min

AxialHelical

Neck mass 200 2.5mm 0.9 100-120cc 3.0cc/s30-45s

Neck CTA 200 0.75mm 0.9 100cc 4.0cc/s15s SP

Non-con Chest 200 2.5mm 0.9 -- --

Nodule F/U ?? 2.5mm 0.9 -- --

Dynamic Chest 200 2.5mm 0.9 100cc 2.0-2.5cc/s60s

HRCT (axial) 200 0.625mm(recon interval 10mm)

0.9 -- --

P.E. 200 0.75mm 0.7 100-120cc 3.0-3.5cc/s25-30sSP MPA

Sharp lung kernel

Runoff 250 5mm 0.7 -- 45s

Trauma/Dissection

300 0.75mm 0.7 100-120cc 3.0-4.0cc/s20-25sSP desc Ao

CAP 300 3-5mm 0.7 100-120cc 2.0-2.5cc/s50-60s

Oral contrast

64-slice CT mAs Slice Pitch Contrast Rate/Delay Other

Trauma AP 300 2.5mm 0.7 100-120cc 3.0-4.0cc/s, 20-25s No oral con

Routine AP 300 3-5mm 0.7 100-120cc 2.0-2.5cc/s, 60s Oral prep

Liver 250 2.5mm 0.7 Non-con +120cc

3.0-3.5cc/s30s + 50-60s

Non-con; 5min or10min delay

Pancreatitis/Mass

250 2.5mm 0.7 Non-con +120cc

4.0cc/s30s + 50-60s

Water prep

Adrenal 250 2.5mm 0.7 Non-con +120cc

3.0-4.0cc/s60s + 15min

Water prep

Renal mass 250 2.5mm 0.7 Non-con +120cc

3.0-3.5cc/s25-30s + 55-60s + 4-5min

No oral con

CT urography(hematuria)

250 2.5mm 0.7 Non-con +120cc

3.0-4.0cc/s 55-60s + 8min;Split bolus technique:-50cc @3cc/s-wait 5min-80cc @3cc/s-wait 100s and then scan

No oral con;Synchronousnephrographic & excretory phases

CT IVP 250 2.5mm 0.7 80cc + 40cc 80cc wait 8min +40cc wait 1min

No oral con; optional KUB

Stone 250 3mm 0.7 -- -- Prone; dual energy

Mesenteric Isc 250 2.5mm 0.7 Non-con+120cc

4.0cc/s25s + 50s

Water prep

Pan ScanREFORMATS FILTER/

KERNELCOVERAGE SLICE

THICKNESSkVp mA

Scout AP and Lateral Vertex thru mid thighs 120 15

HEAD (-IV) Axial (gantry tilt) ST & bone Vertex to skull base 5mm 120 300

Bolus tracking(150cc at 5cc/s)

Ascending aorta(at carina)

CTA NECK (+IV) Axial ST Aortic arch to vertex 2.5mm 120 300

-SKULL Axial Bone Vertex thru mastoid tips 1.25mm

-FACIAL Axial, Sag, Cor Bone Above orbits to below mandible on AP; nose tip to beyond mastoid on lat

2.0mm

-C-SPINE Axial, Sag, Cor Bone Mid orbits to mid clavicles and coned down to spine

1.25mm

CHEST/ABD/PELV(+IV)

Axial ST Above clavicles to lesser trochanters 3.75mm 120 300

-T/L SPINE Sag, Cor Bone Include sternum on Sag; above claviclesthru SI joints

2.0mm

-BONY PELVIS Sag, Cor Bone Above iliac crest thru lesser trochanters 2.0mm

RUNOFF (+IV split bolus)--optional

Axial, Sag, Cor ST Thru SI joints to feet 3.75mm

MIPs

• CTA COW (axial): 4mm thick with 1mm interval/overlap

• CT nodule (axial): 15mm with 2mm interval/overlap

• PE (cor): 15mm thick with 4mm interval/overlap

• CT kidney urogram: 15mm thick with 2mm interval/overlap

When to use Visipaque

• Renal insufficiency or DM

• Prior contrast rxn

• Someone who already received one contrast rxn in preceding 24-36hrs

• PE studies

• Peds

NS Bolus chasing

• Improved use of contrast volume esp within IV line and peripheral vein (10-15cc)

• Decreased volume of contrast needed (ideal in patient’s with borderline renal func to make better use of contrast)

• Dilute dense contrast w/in right side of heart

Oral prep with HOCM agents

• Adult

– 30-90cc

– 1:1 dilution with water

– 13mg Iodine/cc oral (ACR)

– 15mg I /cc rectal (ACR)

• Kids

– 15-60cc (15-30cc <10yo and 30-60cc >10yo)

– 1:3 dilution with water

– 7mg Iodine/cc oral (ACR)

– 9mg Iodine/cc rectal (ACR)

64oz = 2L = 2Quarts

32oz = 1L = 1Quarts

Bagram prep (use this!)

• Oral

– 15cc Gastrograffin in 500cc (16oz) of water bottle to be taken over 1st

hour

– Another 15cc Gastrograffin in 500cc (16oz) of water bottle to be taken over 2nd hour

– Don’t chug

– Total: 2 hr prep with 30cc Gastrograffin in 1L water (32oz)

• Fistulogram

– KUB: 30cc gastrograffin + 30cc water in 60cc Tume syringe

– CT: 5cc gastrograffin + 60cc water in 60cc Tume syringe

• Peds IV

– 1cc per lb (weight-based)

PEG oral contrast for ED 2010 (Tubay)

• No oral contrast

– BMI>29 (overweight) plus…

– Appy, diverticulitis, SBO, mesenteric ischemia, unknown etiology

• Yes oral contrast

– BMI≤29

– Peds

– Renal failure

– r/o abscess, fistula, post-op complication

• Oral contrast regimen (avoid in perforation, high grade obstruction)

– 1L (1000cc) PEG (polyethylene glycol or Golytely)/Gastroview mixture (flavoring optional)

– Start drinking ½ at 0min and other ½ at 20min (finish by 1hr) then CT at 75min

– This mixture is safe in renal failure

• Pre-CT lab (Cr for patients over 50yo or known renal dz or insufficiency)

• Order in Essentrisnotify Rad techRad tech to call Doc

Oral prep by Elliot Fishman

• Recommends using 100 ml Omnipaque-350 (iohexol) PO in 1 gallon (4quarts or 3.8L) of water

• Omnipaque-350 is FDA approved

Oral prepINPATIENT PREP

• NPO after MN if AM exam

• NPO for 4-6hrs after breakfast if PM exam

• 2hr prep for SB

• 3hr prep for rectosigmoid

• May skip oral contrast if patient is not thin (BMI≥25)

• Dilute 40cc of Gastrografin in 2L (64oz) of water (20cc per 1L or 32oz)

• May use Tang or Crystal Light or Koolaid powder

• 2hr prep: Start 2 hrs before exam and drink 500cc or 16oz every 30min

• 3hr prep: Start 3 hrs before exam– 1st hour: Drink 1L (32oz) over 30min

– 2nd hour: Drink another 500cc (16oz)

– 3rd hour: Drink last 500cc (16oz)

• May give 250cc q20min through enteric tube (confirm location of NGT or DHT prior to administration)

Oral prep

OUTPATIENT PREP

• 40cc bottle of Gastrografin

• Mix with 64oz or 2L of water

• May use Tang or Crystal light for flavoring

• Drink in four equal doses (16oz) q30min over 2hrs prior to study

– 2hr before

– 1.5hr before

– 1hr before

– 30min before

CT enterography

• Goal: Evaluate SB and LB

• Starting 2d before exam– Eat low residue and low fiber diet

– Avoid: seeds, nuts, whole grain breads/cereal/pasta, whole vegetables or sauce, whole fruits (including canned fruits), yogurts, pudding, ice cream, creamy soups, tough or coarse meats, peanut butter, salads with seeds or nuts, coconut, marmalade

• Starting 1d before exam– Eat clear liquid diet

– Acceptable: plain water, fruit juices without pulp (eg apple/grape/cranberry juice), fruit punch, broth (bouillon or consomme), plain gelatin, honey, ice popsicle (without fruit pieces), tea or coffee without cream

• NPO after MN before exam (ok to take meds with water)

• Arrive 1hrs before exam and will be given 3bottles of volumen (keep it chilled for better taste; don’t add anything to it b/c already flavored) to drink (drink one bottle every 20min over course of 1hr)

CT enterography

• NPO x 4hr

• Volumen 1.35L over 1hr

– 450cc 1hr before

– 450cc 45min before

– 225cc 20min before

– 225 cc 10min before

• 100-125cc IV contrast @ 4cc/hr + 50cc NS @ 4cc/hr

• Wait 65s before imaging

Volumen prep

• 1hr prep (total of ~900cc volumen)

• Prep– First 450cc bottle of volumen 1hr before

– Second 450cc bottle of volumen 45min before

– 450cc water only, 30min before study

• Scan at 60min

Water (negative) prep

• Drink 1.5L of water in 3 equal doses

– 500cc (16oz or 2cups) 90min before

– 500cc 1hour before

– 500cc 30min before

• Scan at 90-120min

• Alternative prep for abdomen only: 1000cc water PO 30min prior to study + 200cc water PO on table

Rectal contrast• 30-40cc Gastroview (~1/2 bottle) in 1500cc (1.5L) warm tap water (mix vigrously)

• Do rectal exam and lubricate tube prior to tube insertion (left lat decub)

• Administer via BE kit under gravity

• Administer 300cc at a time to allow for cramping to subside

• Total of 1200cc (1.2L) should be sufficient (use less if colon surgery)

• Clamp tube

• Check scout for any need to roll the patient

• Drain to gravity at end of exam

• Alternative negative rectal contrast: 25-30 pumps of air instead of contrast

• Peds rectal contrast

– AVOID RECTAL CONTRAST (per Dr Ayotte) b/c risk of rupture• “Rectal contrast only to be given by surgeron”

– >5yo and <13yo

– 100cc per year of age (same as oral contrast)

– ½ while left side down and other ½ while right side down

CT cystogram

• Place foley (drain bladder)

• DGMC: 50cc Conray (comes in a 50cc bottle) +450cc warm NS bag

– Others:

• Use 25-50cc of any 60% IV contrast (eg Hypaque 60 or omnipaque 300)

• Diluted (5%-10%): 25-50cc contrast in warm 450cc saline bag (remove 25-50cc of saline from saline bag before adding contrast)

• At least 350cc via gravity

BE prep

• 2 days prior to test

– Clear liquid diet only

– Clear broth, juices, coffee, carbonated bev, jello, popcicles (no milk)

• Day before test

– Continue clear liquid diet

– 1, 3, 7, 10pm drink 8oz water

– At 4pm mix and drink phospho-soda (Fleets) laxative w/ 4oz water and followed w/ 8oz water

• ALTERNATIVE=Golytely if age>55, renal dz, high risk for volume depletion, meds affecting intraglomerular hymeodynamics (NSAIDs, diuretics, ACE-I, ARB, aldo blocker) to avoid acute phosphate nephropathy (fill plastic container containing Golytely powder with water and flavoring such as kool-aid and drink 1 glass q15min until all gone; may take Phenergan for nausea)—may come in 4000cc/bottle solution

– At 7pm take 4 Dulcolax (biscodyl) tabs w/ 8oz water

• On day of test

– Drink at least 8oz water/coffee/juices

– No breakfast (no broth)

– 1hr before exam insert Suppository (hold BM for 15min to allow full suppository absorption)

• After test

– Drink plenty of water x48hrs

BE Prep modified (kamal)

• Starting 2days (48hrs) before exam, please eat low fiber (low residue) diet. Please avoid the following types of food:

– Whole grain breads, cereal, pasta

– Whole vegetables, and vegetable sauces

– Whole fruits (including canned fruits)

– Yogurt, pudding, ice-cream with nuts or fruits/vegetables

– Tough or coarse meats with gristle

– Cheese with seeds

– Peanut butter

– Salad dressings with seeds or pieces of fruits or vegetables

– Seeds and nuts

– Coconut

– Marmalade

BE prep modified (kamal)• 1 day before exam:______________

– No solid food today!

– You may only have clear liquid diet (water, clear broths/soup, juice without pulp, coffee/tea without cream, carbonated drinks like coke, jello, popsicles) for breakfast, lunch, and dinner.

– No milk or dairy products!

– OK to take any prescribed medications with water.

– 8am: drink 16oz water.

– 10am: take 2 Dulcolax (Biscodyl) laxative tablets with 16oz water.

– 12pm: drink 16oz water.

– 2pm: drink 16oz water.

– 4pm: start drinking Golytely 1 glass every 15 minutes until all gone.

– 6pm: drink 16oz water.

– 8pm: drink 16oz water.

– No more meals after 11pm!

• Day of the exam:________________

– Need to be empty stomach! (No solid or liquid diet. No breakfast or Lunch.)

– OK to take any prescribed medications with water.

– 8am: drink 16oz water.

– 1hr before exam: insert Suppository in rectum as high as possible and avoid bowel movement for 15min to allow the suppository to take effect.

• After the exam:_________________

– Resume normal diet.

– Drink plenty of fluid for next two days to keep yourself well hydrated and to avoid constipation!

BE prep order

• Dulcolax (Bisacodyl) 5mg PO tab x2 (take by mouth with 16oz water day before exam at 10am)

• Golytely 4000ml/bottle x1 (begin drinking 1 glass every 15-30 minutes on day before exam starting 4pm until all gone)

• Dulcolax (Bisacodyl) 10mg rectal suppository x1 (insert suppository in rectum 1hour prior to exam and avoid bowel movement for 15minutes)

Order set (OSET): “NM Bowel Prep”

CHCS order set (“GI prep”)

• SODIUM PHOSPHATE (FLEETS) 1 ENEMA RECTALLY 3 HOURS PRIOR TO PROCEDURE. REPEAT ONE HOUR PRIOR TO PROCEDURE. ARRIVE AT PROCEDURE 30 MINUTES PRIOR TO SCHEDULED TIME.

• MAGNESIUM CITRATE PO SOLN DRINK ENTIRE CONTENTS OF ONE BOTTLE THE DAY PRIOR TO PROCEDURE

• BISACODYL 5MG TAB (DULCOLAX) TAKE 2 TBS PO DAY PRIOR TO PROCEDURE

• FLEETS PHOSPHO-SODA ORAL SOLN DRINK 3 TABLESPOONSFUL (45 ML) MIXED IN 4 OUNCES OF WATER AT 1600 & 1900 THE DAY PRIOR TO PROCEDURE (FOLLOW EACH DOSE WITH 4 EIGHT OUNCE GLASSES OF WATER)

*MR Safety & contrast

ZONE DESCRIPTION HAZARDS

Zone I Uncontrolled (freely accessible to general public)

Outside MR department

None

Zone II Waiting room with unscreenedpatients

Minimal

Zone III “Restricted access”Right outside scanner room

Accessible to screened patient only Escorted by MR staff

Need to resusitate pts here

-potential biostimulation interference

Zone IV “Restricted access”MR scanner room itself

“5-Gauss” line

-Biostimulation interference-RF heating

-missle effect-cryogen

-noise

Handheld magnet ≥1000Gauss

MR quench procedure

• Magnet vent failuresudden release of cryogen vapor from MR magnet (“quenching”)can result in asphyxiation (suffocation), frostbite or injuries due to panic

• Seen as white cloud or “fog”

• Need to evacuate patient quickly but calmly

• When entering room, stay low and help patient exit room

MRIBefore the exam you will be asked to fill out a screening form asking about anything that might create a health risk or interfere

with imaging. Items that may create a health hazard or other problem during an MRI exam include:• Cardiac pacemaker or implantable defibrillator • Catheter that has metal components that may pose a risk of a burn injury • A metal clip placed to prevent bleeding from an intracranial aneurysm • A medication pump (such as that used to deliver insulin or a pain-relieving drug) • A cochlear (inner ear) implant Items that need to be removed by patients and individuals before entering the MR system room include:• Purse, wallet, money clip, credit cards, cards with magnetic strips • Electronic devices such as beepers or cell phones • Hearing aids • Metal jewelry, watches • Pens, paper clips, keys, coins • Hair barrettes, hairpins • Any article of clothing that has a metal zipper, buttons, snaps, hooks, underwires, or metal threads • Shoes, belt buckles, safety pins Objects that may interfere with image quality if close to the area being scanned include:• Metallic spinal rod • Plates, pins, screws, or metal mesh used to repair a bone or joint • Joint replacement or prosthesis • Metal jewelry such as that used with body piercing • Some tattoos or tattooed eyeliner (these alter MR images, and there is a chance of skin irritation or swelling; black and blue

pigments are the most troublesome) • Bullet, shrapnel, or other type of metal fragment • Metallic foreign body within or near the eye (such an object generally can be seen on an x-ray; metal workers are most likely

to have this problem) • Dental fillings (while usually unaffected by the magnetic field, they may distort images of the facial area or brain; the same is

true for orthodontic braces and retainers)

(not epicardial leads)

MR safe/conditional/unsafe

• MR Unsafe

Aneurysm clip

LV assist device

Breast tissue expander

Pacemakers/ICD

Neural stimulators

Infra aortic balloon pump

Swan ganz catheter (can melt from the generated heat!)

Intra-ocular foreign body

Cochlear implant

Linx (reflux magnets)

Temporary transvenous pacing

EEG electrodes

Pillcam (capsule endoscopy)

• MR Conditional

Parachute LV aneurysm device

Intrabronchial valve (one device is MR safe)

Cardiac valve replacement

CardioMEMS device

Leadless pacemaker

Medtronic MRI revo MRI safe pacemaker / SureScan device -- ONLY for non-thoracic scans!!

Cardiac valve

Glaucoma shunt tubes (except ExPRESS)

• MRI Safe

ASD occlusion device

Coronary stents (unless multiple >10cm)

Essure inserts (and contraceptive diaphragms)

FYI: Some tattoos contain iron oxide - and can cause burns. Can try to coat with Vaseline or ice packs prior to

scanning. Also, medication patches can cause burns and should be removed prior to scanning (we have a P&P

regarding this already).

NSF (nephrogenic systemic fibrosis)

• Severe delayed fibrotic rxn of body tissue to some Gd-based contrst media

• Clinical

– May develop from the day of exposure up to 2-3mos

– Starts w/ red, painful, itchy swelling in legs and arms

– Progresses to fibrotic lesions of the skin and subq tissues and occasionally of the internal organs

– Fatal in some cases

• Risk factors (check Cr 3-5days prior to exam if 50years or older)

– Renal impairment incld pts on dialysis

– Age<1yo (immature renal fxn)

– Pregnant pts (does not matter what actual maternal renal fxn is)

– GFR<60mL/min (not been reported in GFR>60)

• Has occurred w/ Omniscan (Gadodiamide), Magnevist (Gadopentetate dimeglumine), OptiMARK (Gadoversetamide)

• To reduce risk:

– Use Gd that has not been assoc w/ development of NSF

– Use lowest possible dose

– Allow atleast 1wk before administering more Gd-based agents

NSF (nephrogenic systemic fibrosis)• Only 2 cases of NSF with GFR 30-59

• NSF=systemic

• NFD=dermopathy

• Painful skin thickening and systemic d/o (systemic fibrosing d/o)

• On dialysis (highest risk) = no Gad

• GFR 0-30 = no Gad (prompt hemodialysis w/in 2hrs of Gad)

• GFR 30-59 = discuss w/ ordering provider (risk out weigh benefit) + consent

• GFR ≥60 = Gad OK (no restrictions)

• Omniscan has the highest risk

• Magnevist (no cases with GFR>60)

• Multihance (no cases; with GFR 30-60, use ½ the dose)

• Prohance is multicyclic (rest are all linear)

• Risk is dose dependent

– Single dose 0.1mmol/kg

– Double dose 0.2mmol/kg

• Risk factors

– Major: renal failure and Gad dose

– Others: inflammatory process, hypercoaguable, recent surgery/hospitalization, liver d/o, cardiothoracic d/o

NSF (nephrogenic systemic fibrosis)

• If patient has acute renal failure (do prompt dialysis)—hemodialysis does clear Gad

• Once Gad dissociates from DTPA, it goes into extracellular space and may not clear despite dialysis

• Who gets Cr (for GFR)?

– Renal insuff

– DM

– Age>60

– Nephrotoxic drugs (like NSAIDS etc)

– MM

– CVD

– Renal transplant

– Severe liver dz

– CHF

chelate NSF cases (as of 2007)

Omniscan linear 180

Magnevist linear 78-92

Multihance linear 1 (confounded case)

Prohance cyclic 0

Dotarem cyclic 0

GFReGFR Renal function

>89 Normal

60-89 Mildly reduced

30-59 Mod reduced

15-29 Sev reduced

<15 Renal failure

eGFR is normalized to BSA and by sex/age/race=black vs non-black.

If black, multiply by 1.2

ACTION COMMENTS

<60yo and GFR ≥60 Magnevist

>60yo Multihance

GFR 30-59 Consent + Multihance(don’t Give gad if on

dialysis)

-make sure study is indicated (d/w ordering physician)-Use single dose Gad (0.1mmol/kg)-Don’t use Omniscan-Some recc Multihance or Prohance-Get informed consent

GFR ≤30 No Gad -Get nephrology consult for special circumstances

On dialysis No Gad

OLD POLICY

NEW POLICY

GFR ACTION COMMENT

>40 GIVE GAD

30-40 CONSENT -Make sure study is indicated (d/w ordering physician)-Use single dose Gad (0.1mmol/kg)-Don’t use Omniscan-Some recc Multihance or Prohance-Get informed consent

15-29 AVOID GAD -Get nephrology consult

ON DIALYSIS AVOID GAD

ACR policy to check Cr and eGFR

KP policy1. The following screening questions must be answered:

• Are you 60 years of age or older?

• Do you have chronic kidney disease (including solitary kidney, renal transplant, renal tumor)?

• Do you have diabetes?

• Do you have hypertension?

• Do you have chronic liver disease?

– For patients with severe liver disease or pending liver transplant, need GFR within 3 days.

– If the patient does not have a GFR within 3 days, contact the radiologist.

– This 3 day requirement may be extended to 6 weeks by the radiologist if: the GFR is well above the threshold >45ml/min, the GFR is not trending downward and the liver disease is stable.*

• If the patient answers yes to any question, they are “high risk”.

• If the patient answers no to all questions, they are “low risk”.

References

• SCPMG Consensus Statement on the Appropriate Use of Gadolinium-based Contrast Agents for MRI and MRA; August 15, 2007.

• FDA Information for Healthcare Professionals: Gadolinium-based Contrast Agents for MRI; FDA Alert 6/2006, updated 12/2006 and 5/23/2007.

• Updated ACR Screening Recommendations on Gadolinium-based MR Contrast Agents, Renal Disease Patients, and Nephrogenic Systemic Fibrosis (NSF); July 2007.

KP policy2. Check for the most recent GFR in all patients. “High risk” patients must have a GFR within the time frame noted below. The units are ml/min.

• GFR>60 within 6 months of MR scan date. OK for schedulers to schedule. OK for techs to inject Magnevist/Gadavist or Eovist (for liver) or MultiHance (MultiHance double dose OK for cardiovascular studies).

• GFR>45 within 3 months of MR scan date. OK for schedulers to schedule. OK for techs to inject Magnevist/Gadavist or Eovist (for liver) or MultiHance single dose (MultiHance 1.5x dose OK for cardiovascular studies).

• GFR 30-45 within 6 weeks of MR scan date. OK for schedulers to schedule during weekdays from 9am to 5pm. Techs contact radiologist prior to injecting Gadavist or Eovist (for liver) or MultiHance single dose.

• In all patients under 18 y/o, the GFR is not reported in HealthConnect. Check for the most recent creatinine. Use the following website to calculate the GFR. You will need to know the patient’s height in cm.

• http://www.nkdep.nih.gov/lab-evaluation/gfr-calculators/children-conventional-unit.shtml

• The radiologist must be contacted if the GFR<45 ml/min. The reason to contact the radiologist if the GFR is 30-45 is to check for the trend. Patients in acute renal failure can initially have a GFR >30 ml/min.

• Do not inject if the GFR<30 ml/min. Contact radiologist to consider a scan without contrast.

• Note that a radiologist can approve an exception on a case by case basis in patients who do not meet any of the above criteria.

• If the patient answers no to all screening questions, they are “low risk”. It is ok to schedule and inject without a GFR. However, still check the patient’s labs to make sure that if they have had a GFR, it was not abnormal (GFR <60). If their last GFR was abnormal, they are now “high risk” and must meet one of the 3 criteria.

• These guidelines apply to oral Gadolinium as well. If the GFR < 30 oral Gadolinium shall NOT be administered.

KP policy

Exceptions:

• 1. Gadolinium can be administered to a patient with GFR below 30, if the following two criteria are met:

– IV gadolinium is deemed absolutely necessary with no imaging alternative (very rare).

– Informed consent must be documented by the ordering clinician (risks and benefits discussed with patient and patient agrees to receiving IV gadolinium).

• 2. For dialysis patients, prompt post-procedure dialysis is recommended, although this has not been proven to eliminate the risk of nephrogenic systemic fibrosis.

• 3. Patients may be scheduled for an MRI arthrogram without a recent GFR as long as the patient is not on dialysis. If the patient is on dialysis, please contact a radiologist.

• 4. Changing from a with and without contrast to a noncontrast study: If the patient refuses contrast or asks for the MRI scan to be stopped, the technologist may stop the procedure without calling the clinician to obtain a formal order change. The technologist must document on the requisition the reason for stopping the exam. The radiologists must also note the reason for stopping the exam in the final report.

Ablavar• Blood pool agent (Gad-based)

• 10cc (less risk of NSF due to lower dose)

• Lasts in BP for ~1hr

• Hepatic and renal excretion

• FDA approved (not for peds)

• MRA (esp runoffs)

– 1st pass dynamic

– Steady/state MRA

• Longer acquisition

• Higher resolution

• Both arterial and venous activity

• Reformat thin MPR in coronal and sagittal

*MR Protocols

Abdomen MRI• SSFSE localizers (fast T2 w/o FS)

• Ax T1 (without fat-sat)

• Ax T2 FSE FatSat (with resp gating/triggering)

• Ax/Sag/Cor SSFSE (single-shot echo train)

– Fast acquisition T2 weighted w/o FS (but less T2 weighted than true T2 FSE)

– Avoids bowel motion

– Great for distinguishing solid from fluid (compare to spinal fluid)

• DWI with different b values (highly sensitive for lesions esp LAD; b=0 and b=600; ADC map)

• Ax T1 FSPGR dual echo breath-hold (spoiled GRE in/out phase)

– TE=4.4msec in-phase and 2.2msec out-phase for 1.5T

– In-phase= T1 with FS

• Ax T1 FAME or LAVA pre-gad

• Ax T1 FAME or LAVA post-gad immed and 1, 3, 5min (15min delayed)

• Cor T1 FAME or LAVA post-gad (performed last)

• MRCP (heavily T2 weighted HASTE or FRFSE)

– 3D

– Multiple thin slabs 2-4mm (axial, oblique, coronal, radial)

– Single thick slab 4-8cm

• 3D SSFP or FIESTA (TruFISP on Siemens)—useful to assess vascular patency w/o administering Gad (flowing blood and fluid is bright)—remember it is both T1/T2 (can do w/ or w/o FS)

Abdomen MRI (Philips)

• SS TSE (similar to SSFSE)

• bTFE FS (similar to SSFP or FIESTA)

• T2 TSE free-breathing

• T2 SPIR resp-triggered (fat-sat)

• Dual FFE (in/out out of phase)

• DWI

• Ax/cor THRIVE (multiphase post Gad FS)

What and Why of abdomen MRI• SSFSE localizers (fast T2 scouts w/o FS)

• T1 SPGR in-phase (basically T1 w/oFS)

• T1 SPGR out-phase (for microscopic fat like adrenal adenoma; also good for fatty liver; compare lesion to spinal fluid to determine fluid vs solid)

• SSFSE (fast T2 w/o FS avoids bowel motion; good for anatomy; less T2 weighting than T2 FSE)

• 2D or 3D SSFP (both T1/T2 weighted; can do with or without FS; good for assessing vascular patency)

• T2 FSE FS (usually requires resp triggering/gating b/c long acquisition; affected by bowel motion; look for macroscopic fat)

• DWI (highly T2w; very sensitive for lesions esp LAD; performed at b=0 and b=600; compare with ADC map which is better is more b values are used; things that get brighter with increasing b values are generally not shine-thru)

• Pre-Gad mask (basically T1 FS)

• Post-Gad dynamic multiphase T1 GRE FS (immediate, 1, 3, and 5 min)—may do 15min or even 1hr delayed

• Subtraction imaging (subtract pre-Gad mask from various contrast phases)

• Post-Gad cor T1 GRE FS (done after all axial dynamic series so it is the most delayed post-Gad scan)

• MRCP (heavily T2 weighted imaging; 3D fast recovery FSE aka FRFSE or thick and thin slabs)

LIVER/SPLEEN PANCREAS

SSFSE (w/o FS) S>L P=L

FIESTA w/o FS S>L P=L

FIESTA w/ FS S=L=P

T1 inphase (w/o FS) L>S P=L

T1 FS L>S P=L

T2 FS S>L P=L

Pelvic MRI

• SSFSE ax/cor/sag (w/o FS)

• T1 with and without FS

• T1 SPGR dual echo (in/out of phase)

• T2 with and without FS

– Axial (whole pelvis)

– Oriented to endometrial stripe

• Axial (perpendicular), Cor (parallel), Sag (to stripe)

• T1 GRE FS post gad (ax/sag/cor)

What and Why of pelvic MRI• SSFSE

– T2 w/o FS

– Assess anatomy

• Sag and angled T2 (axial/coronal)

– Determine T2 characteristics

– Look for macroscopic fat on FS imaging

– T2 dark lesion: consider blood/calc

– Uterine anomaly and endometrial stripe

– Look for fibroids and adenomyosis

• T1 in/out of phase

– Determine T1 characteristics

– Look for microscopic fat on out-of-phase

– T1 bright lesion: consider fat/proteinaceous/blood

• Post Gad T1 FS (look for enhancement)

ABD/PELV MR PROTOCOL (Azuar)• DYNAMIC LIVER: with Gad

– Modifications: MRCP / hemangioma / FNH / CholangioCA

• PANC MASS: with Gad (include MRCP)

• RENAL CYST/MASS: with Gad

• RENAL MRA: with Gad

• ADRENAL MASS: without Gad (for adenoma) / with Gad (pheo or met)

• MRA ABD AORTA: with Gad

• ROUTINE ABDOMEN (in someone who cant get CT): with Gad

• ROUTINE PELVIS (in someone who cant get CT): with Gad

specify Male / Female

• PROSTATE (not a screening study): with Gad

• FEMALE PELVIS: with Gad (fibroid/adenomyosis/adnexal mass)

– Modifications: Anomaly suspected / Endometrial CA staging / Cervical CA / Urtheral abnl

Body MR protocols (Tubay)• Dynamic Abd/Liver/Panc

– Cor FIESTA (SSFP)

– Ax SSFSE

– Ax T1 in/out phase

– Ax T2 FS (resp gated)

– Ax DWI (resp gated; b0=600)

– Ax T1 LAVA FS (pre-gad)

– Ax T1 LAVA FS multiphase postGad (30s, 1min, 3min, 5min)

– Cor T1 FS postGad

• Hepatocellular mass (with mulihance or Eovist)

– Dynamic abd protocol + Delayed ax/cor T1 FS postGad (60min multihance)

• MRCP (cor 3D T2 MRPC with oral prep, resp gated)

• Cholangio– Dynamic abd protocol + MRCP +

Delayed ax T1 FS postGad (15min)

• Adrenal– Dynamic abd protocol (extend resp

gated Ax T2 FS from adr to aortic bifurcation) + Cor T1 in/out phase + Cor T1 LAVA FS (pre-gad)

• Renal mass– Dynamic abd protocol + Sag FFSE +

Sag T1 FS postGad + preform subtraction for axial pre/post-gad

• Aortic/Renal MRA– Ax/cor FIESTA (SSFP)

– Ax SSFSE

– Ax T2 FS

– Cor T1 pre-gad

– Cor T1 3D MRA postGad dynamic

– Ax/cor/sag T1 postGad (3min)

Body MR protocols (Tubay)• Enterography

– Ax/cor/sag SSFSE

– Cor FIESTA (SSFP)

– Dynamic Cor FIESTA at 2 positions

– Ax T2 FS

– Ax/cor T1 FS

– Dynamic T1 FS postGad (30s, 3min, 5min)

– Ax T1 FS postGad

• Appendicitis (with gastromark)

– Ax/cor/sag SSFSE

– Ax/cor FIESTA (SSFP)

– Ax T2 FS

– Ax T1

• Thoracic aorta

– Ax/cor/sag FIESTA (SSFP)

– Ax/sag SSFSE

– Ax T1 FS

– Candycane (oblq sag) T1 3D MRA postGad dynamic

– Ax/cor T1 FS postGad

• Femal Pelvis (surgilube vag)

– Cor FIESTA (large FOV with kidneys)

– Ax/sag T2 FRFSE (fast-recovery FSE)

– Angled T2 (ax T2 perpendicular to stripe; cor T2 parallel to stripe)

– Ax T1 in/out phase

– Ax T1 FS pre-gad

– Ax/sag/cor T1 FS postGad

• Fibroid (pre UAE only)

– Femal pelvis protocol (do Ax T1 instead of in/out phase) + Cor T1 3D MRA postGad dynamic (to be done before ax/sag/cor T1 FS postGad)

• Male Pelvis

– Cor FIESTA (SSFP)

– Ax SSFSE

– Ax/sag T2

– Ax T2 FS

– Ax/Sag T1

– Cor STIR

– AX T1 FS

– Ax/sag/cor T1 FS postGad

Body MR protocols (Tubay)• Dynamic female pelvic floor

– Ax SSFSE

– Cor FIESTA (SSFP)

– Ax/sag T2

– Ax T2 FS

– Dynamic sag FIESTA with strain (x3)

– Ax T1

– Ax T1 FS

– Ax/sag T1 FS postGad

Fat suppression techniques• Chemical fat sat (FS)

– Freq-selective saturation RF pulse (same freq as lipid) applied to each slicethen apply homogeneity spoiling gradient pulse to dephase lipids

– ADV: lipid-specific so works well with post-Gad imaging; also can be used with any imaging sequence

– DISADV: inhomogenous fat suppression esp with metal or near air collections; increases imaging time; does not work well with lower field strength magnets

• Inversion recovery (STIR)

– Suppression is based on fact that T1 of lipid is shorter than that of water (180deg inversion pulsefat recovers faster than waterapply 90deg pulse at null point of fat); for 1.5T Tinull ~130-170ms

– Need optimal TI to null fat signal

– Usually performed with FSE

– ADV: insensitive to field inhomogeities (good for metal); can be used with low field strength magnet

– DISADV: overall lower SNR; may suppress tissue with similar T1 as fat (like mucoid tissue, hemorrhage, proteinaceous fluid, Gad, or melanin); optimal TI may vary btwn anatomic location and individuals (TI tuning techniques based on spectral display have been developed)

• Out-of-phase (microscopic fat or intra-voxel fat)

– Based on phase-differences in images at different echo times

– In-phase=lipid and fat signal is additive; Out-of-phase=india-ink

– Good for adrenal adenoma and steatosis

• Dixon technique

– Based on phase difference

– Both in-phase and out-of-phase images acquiredsum of these gives you pure water imageAND subtraction of these gives you pure fat image

– DISADV: susceptible to field inhomogeniety like chemical fat sat

3T• PROS

– SNR increases linearly with field strength (but also more artifacts)

• 2x Bo (double mag field strength) = 4x signal (quadruple the signal)

– This means 2x SNR (in theory) but 1.7x SNT (in practice)

– Also 2x noise (noise doubles)

• 2x SNR can be used to

– Increase image quality by

» Smaller FOV (better for small parts)

» Increasing matrix size (better res)

» Thinner slices (allows 3D isotropic imaging)

» Better fat suppression (better fat and fluid peak separation)

– Increase speed

» Decrease scan time by decreasing Nex, decreasing TR, and increasing parallel imaging acceleration factor

» Decrease motion artifact

» Faster dynamic imaging

» Overall increased pt thru-put

• CONS

– SAR increase by 4x from 1.5T to 3T

– Higher susceptability artifacts

– Higher flow artifacts

– More audible noise from gradient pulses (3T 10x louder than 1.5T esp GRE sequences)

– Chemical shift doubles (need to increase BW)

– More magic angle artifacts

ABD 3T• 3plane localizers SSFSE

• FIESTA with ASPIR

– T1/T2

– ASPIR=inversion FS (as apposed to chemical fastsat)

• T2 SSFSE with FS

– SSFSE=single shot echo train

– True T2

• T2 FRFSE RTr FS

– FRFSE=fast recovery FSE (like T2 but has better detail and more signal from fluid)

– RTr=respiratory trigger

– 6mm slices (1mm spacing)

• 2D dual echo

• 3D dual echo (doesn’t work well)

• 3D LAVA with Flex (substitute to dual echo)

– LAVA=T1

– FLEX=can acquire 2 different TE (2pt dixon): pure fat (F)=water suppressed (aka fat imaged), pure water (W)=fat suppressed (aka water imaged), in/out phase (TE=2.5 and 1.3)

– IDEAL=can acquire 3 different TE (3pt dixon): pure fat, pure water, fat+water

• 3D LAVA with Flex +Gad (multiphase)

– 30s, 60s, 90s (1.5min), 120s (2min), 3min, 5min

• Axial DWI RTr with multiple B-values

MSK 3T

• Cant trust T1 FS b/c lesions may falsely be bright (so prefer T1 without FS over T1 FS)

• CUBE

– 3D FSE

– Better for neuro

– Long scan so susceptible to motion

– 3D isovoxel (1mm slice)

• IDEAL

– 3pt dixon

– fat (F), water (W), in-phase (/out phase

• Chemical FS options

– FS (100%): can adjust fast sat efficiency (percentage like 0.9=90% or 0.85=85%)good for marrow signal or ST

– Fat classic (75%too grey)

• ASSET (3rd gen parallel imaging; phase or slice)

• AST (parallel imaging)

• ARC (4th gen parallel imaging; both phase and slice; less artifact)

• MERGE=T2*

• PROPELLER=radial K-space (faster; better contrast res but sl worse spatial res)

Fancy imaging• 2D bSSFP w/ FS (bulletproof MRI)

– FIESTA, TruFISP

• 3D GRE pre/post Gad (multiphase)

– LAVA (GE), THRIVE (philips), VIBE (siemens)

– As sharp as 2D SPGR

• 3D FSE (aka CUBE, VISTA, SPACE)

• 3D dual echo with dixon reconstruction

– 2 vs 3 point Dixon technique

– Pure fat image

– Pure water image=used for post-Gad (replaces LAVA) b/c more homogenous fat sat, higher SNR, sharper image, less susceptibility artifact, less parallel imaging artifact, less phase artifact

– W+F= in-phase

– W-F= out-phase

• DWI

– Single Shot SE (fast acquisition, a slice per sec) w/ EPI

– Minimum TE (decreases artifacts), TR~3000, 2-3 nex, B=20 and 500

– Supress water/fluidgood for LN and tumor (inverted MinIPlooks like PET)

– Can do whole body (body coil, B=500)

DIXON 3-point

3-point DIXON

• Useful technique for fat suppression (esp abdominal imaging with 3T)

• Basically a GRE sequence where 3echoes are acquired at different TEs

• 4 sets of images are obtained– In-phase

– Out-of-phase

– Water-only (aka fat suppression)

– Fat-only (not very useful)

• GE (IDEAL=3-point, FLEX=2-point), Philips (mDIXON), Siemens (DIXON), and Toshiba (WFOP)

• Limitations=inhomogenous fat suppression in small areas like neck or around metal hardware

• “Fat-water swap” artifact (see next slide)

Fat-water swap artifact (DIXON)

Propeller

• Used for uncooperative pts in brain imaging T2 and FLAIR

• Sample k-space in a rotating fashion using a set of radially directed strips or blades

• Each blade is composed of multiple parallel phase-encoding lines that can be collected using FSE or GRE methods

• 8-32 blade lines are acquired in single shotblade then rotates a small angle (10-20deg) at which time a second set of data is acquired

• GE=Propeller, Siemens=Blade, Philips=Multivane, Toshiba=Jet, Hitachi=Radar

TRICKS

• Time-resolved imaging of contrast kinetics (TRICKS) increases temporal resolution of dynamic 3D CE-MRA/MRV studies

• Siemens=TWIST

• Philips=TRANCE

ASL perfusion

• Arterial spin labeling

• No gad needed

• Tagged water proton in arterial blood

• Estimates CBV

• Useful in kids and pts with renal dz

• Useful in Neuro tumor imaging and to differentiate tumor vs necrosis

GE Philips Siemens

Fast SE FE TSE TSE

Single Shot SSFSE SSTSE HASTE

Gradient Echo GRE FFE GRE

Spoiled Gradient SPGR T1 FFE FLASH

Balanced SSFP FIESTA b-FFE TruFISP

Ultrafast GRE FGRE, FSPGR TFE TurboFLASH

Volume GRE FAME THRIVE VIBE

Inversion Recovery IR, MPIR, FastIR IR, IR-TSE IT, TIR

STIR STIR STIR STIR

Parallel imaging ASSET SENSE iPAT

Silicone Fat Water

T2 FSE high med very high

T2 FSEwater sat

high med low

T1 FS very low med low

FSEIR high very low very low

Breast MRI

MR enterography• NPO overnight (~6hrs)

• Volumen (3-4bottles) over 1hr

• Check coronal scouts (SSFSE) to assess volume prep and ensure contrast within ileocecal jct

• Glucagon 1mg IM (if not diabetic)can give IV slow over 1min with NS flush (but doesn’t last as long)

– Glucagon causes hyperglycemia

– Advice pt to drink OJ right after exam for reflex hypoglycemia (crash)

– Advice pt to avoid heavy meal for next 2 hr (bowel hypomobility can lead to nausea)

• IV Gad also given

• Sequences

– Cor SSFSE (interleaved with multi-acq at same slice location mimics cine for peristalsis) w/o BH

– Cor SSFP

– Axial/cor SSFP with FS

– Pre-Gad axial GRE FS

– Post-Gad axial/cor GRE FS

• Real-time (non-BH) to assess for any true stricture vs peristalsis

Dual Source CT• 80 and 140 kVp (for obese use 100 instead of 80)

• FOV of 50cm for low kVp and 33cm for hi kVp

• 3 separate set of images (80kVp, 140kVp, and mixed/blended)

• Mixed/blended has appearance similar to traditional 120kVp

• Blending can be varied (0.3 to 0.7; 0.5 means 50%-50%; 0.7 means 70% contribution from 80kVp and 30% from 140kVp; blending can increase CNR)

• 80kVp has more contrast and noise while 140kVp has less contrast and noise

• Attenuation of iodine is higher at lower kVp CT

• Limitation=small FOV can be an issue for large pts; also image noise is higher in obese pts

• Uses

– Renal tumor (tumor is higher attenuation than hyperdense CT on 80kVp)

– Urinary calculi (red=uric acid; blue=calcified or calcium oxalate)

– Virtual unenhanced CT

– Iodine maps

– Bone subtraction for CT angiographic images

– Renal stone content analysis

– Color-coded images superimposing iodine distribution on virtual unenhanced data

Pregnancy and Fetus

CT in pregnancy: Risks and Benefits (applied rad oct 2013)

• Background radiation to fetus over 9mos of gestation is 0.5 to 1mGy

• Safest imaging test in pregnancy is ultrasound

• Plain films: negligible dose to fetus when fetus not in field of view (recc lead shield over gravid uterus)

• CT: focuses collimated beam of Xray to region of interest so if fetus not in FOV dose is negligible

– Delay CT until after 1st trimester if possible

– Lead shielding not helpful but done anyways (for reassurance)—place shield after scout is obtained

– OK to give IV (class B agent) and oral contrast in pregnancy (very little iodinated contrast crosses placenta and enters fetal circulation and also there is no risk of thyroid dysfunction)

• MRI (≤1.5T): safe in all trimesters of pregnancy; safety of 3T not proven– Gad is contra-indicated in pregnancy (class C) b/c crosses placenta and circulates in fetal

circulation indefinately

Fetal absorbed doseXRAY or CT Fetal absorbed dose (mGy or mSv)

C-spine (AP/lat) <0.001

CXR (PA/lat) 0.002

T-spine (AP/lat) 0.003

Abdomen Xray (AP) 1-3

L-spine (AP/lat) 1

Limited IVP 6

BE 7

CT head 0

CT PE 0.2

CT abd 4

CT abd/pelv 13-25

CT KUB 10

BACKGROUND (over 9mos) 0.5-1

10mGy=10mSv=1rad

Ionizing radiation• Potential harmful effects

– Deterministic (due to cell death)• ADULTS

• Eg: skin erythema, hair loss, cataracts

• Threshold 1000mSv (not observed in diagnostic CT)

• FETUS

• Teratogenic (prenatal death, MR, small head size, IUGR, organ malformation)

• Threshold 50-100mSV and only occur during first 15wks post-conception

• >100mSV or >10rad (some say 150mGy): may need to consider therapeutic abortion (single abd/pelv CT is <50mSv so becomes a concern when multiple or multiphase exam performed)

– Stochastic (due to DNA damage)• Cancer for both adults (eg mom) and fetus

• Probability (rather than severity) increases with increasing dose (cumulative) and no safe threshold (aka linear no-threshold model)

• BEIR VII: background risk of CA over individual lifetime is 42% in adult (in kids it is 0.14%)

• Exposure to 100mSv increases this risk by 1% (risk greater for women and children)

• Exposure to 10mSv increases this risk by 0.1%

• Exposure to 10mSv in utero increases risk of childhood CA before age 15 by 0.06% (40% increase)

• Exposure to 10mSv in newborn increases risk of lifetime CA by 0.4% and 50mGy by 2%

• Risk is cumulative over lifetime

• Adults: thyroid, breast, lung, stomach, colon, and leukemia

• Kids: mainly leukemia

• Fetus: leukemia and solid organ CA

• Increased risk of CA in fetus exposure to in-utero dose as low as 10mGy

• However, consensus is that risk is low (1%) with single CT abd/pelv that exposes fetus to 25mGy

GEST AGE

STAGE OF DEV BIO EFFECTS TO FETUS Risk at

0-2wks Pre-implantation Pre-natal death (all or none) >50-100mSv(animal studies)

1-8wks Major organogenesis IUGR >200mSv(animal studies)

2-8wks Major organogenesis Organ malformation >100mSV

2-15wks Organogenesis and neural dev/migration

Small head size (not decreased IQ) No threshold (some say >100mSv)

8-15wks Neural dev/migration Severe MR >100mSV (not seen <10mSv)

2wks to term

Post-implantation Childhood CA(<15yo) No threshold

In-utero effect of diagnostic level of ionizing radiation (0-250mSv)

CT in Pregnancy• Consent needed for all CT; and also 1st trimester MR

• Delay CT until after 1st trimester if possible

• CT head ok; limit CT chest to 2cm below dia; low dose tech for CT

• Use shield over gravid uterus (after scout is done)

• Organogenesis 2-15wks

• Teratogenesis (non-stochastic with threshold of 5rads or 50mGy)– Microcephaly, micro-opthalmia, MR, growth retardation, behavorial defects, cataracts

– Extremely unlikely before 2wks and after 15wks

• Carcinogenesis (stochastic effect)– Baseline relative risk of fatal childhood CA = 1 in 2000

– After 5rads relative risk of fatal childhood CA = 2 in 2000 (risks doubles)

• Pelvic CT in 1st trimester ~2.4rads (24mGy)

• Pelvic CT in 3rd trimester ~4.6rads (46mGy)

• Health Physicists to calculate and document fetal dose

• Pregnancy termination advisable for fetal dose >10rads (100mGy)

IV contrast in Pregnancy/Breastfeeding• IV contrast for CT should be avoided in pregnancy (although is safe)—avoid esp 1st

trimester

• Believed to be extremely low passage of contrast to fetal circulation

• Possible neonatal hypothyroidism with ionic (not with non-ionic) contrast

• Screen neonate for hypothyroidism after birth (as is usually done)

• IV Gad for MRI is contra-indicated (category C by FDA)

• Consent needed for perform MR if 1st trimester (avoid MRI in 1st trimester unless absolutely needed since risk of spontaneous abortion is high in 1st trimester and ppl may blame MRI for it)

• 10day rule: if more than 10d have past since 1st day of last menstural period, patient needs a pregnancy statement

• May cease breastfeeding for 24hrs after contrast administration (pump and dump)

– <1% of adm dose excreted into milk

– <1% of dose ingested by infant is absorbed from GI tract

– Hence, <0.01% of dose given to mom is actually absorbed by infant

– This is <1% of recc dose to infant undergoing imaging study (usually 2cc/kg)

Guidance• APPY

– Ultrasound first in 1st or 2nd tri (but often non-diagnostic later in pregnancy esp >35wks)

– ≤1.5T MRI w/o Gad (1st or 2nd trimester)

– CT w/ IV+oral (esp if peritoneal signs)

• RENAL STONE

– Ultrasound first (cant see ureteral stone; physiologic hydronephrosis R>L seen in 2nd/3rd trimester; ureteral jets may be unilaterally absent in normal preg pts)

– CT KUB non-con (perform with IV contrast if ddx also includes appy)

– don’t do IVP

• OVARIAN

– Ultrasound or ≤1.5T MRI (w/o Gad)

• PE

– D-dimer not useful

– Consider bilat LE u/s for DVT

– ACR guidelines rate both CTA and VQ same in pregnancy

• If normal CXR: perform Q only

• If abnormal CXR: perform CTA (limit to 2cm below dia)

• PELVIMETRY

– Low dose CT

• TRAUMA

– At level I trauma center, mother is imaged same as non-preg women

CT vs VQ in pregnancyFetal dose Breast dose Comment

CTA 0.003-0.13mGy (depends on trimester)

0.2-2.2% increased lifetime relative risk of breast/lung CA

Perform if abnormal CXR

Q only Q only=0.12mGy VQ=0.32mGy(V=0.2mGy)

Q=0.28mGy Perform Q only ifnormal CXR

Background (over 9mos)

0.5-1mGy

Consenting patients• Primum non nocere (first do no harm)

• Informed “decision” vs “consent”

• Clinician responsibility=justification of exam and ultimately radiation exposure

• Radiologist responsibility=optimize exam (balancing diagnostic accuracy with radiation exposure)

• Consent important for: preg patients and for any exam ≥50mSv

• Radiologist as advocate/informer/advisor (not paternalistic; cannot make decision for patient)

• Exam benefits (more info to clarify diagnosis and direct therapy; CT can rapidly and accurately provide this info)

• Reasonable alternatives

• Radiation risks– risk from CT is small if risk at all

– we are not certain that there is a risk at very low doses

– no hard facts; just based on data from atom bomb survivors and nuclear radiation workers; based on assumption and hypothesis

– effect of small rad doses can take years to take effect (if any)

– risk of lifetime CA from 10mSv (500 CXR or 1 CT abd/pelv) is 1 in 1000 in 40yo pt and 1 in 100 in 1yo infant

– if you compare this is baseline risk of CA of 1 in 5 in USA

– risk of missing serious diagnosis will occur now in coming min/hrs/days

• ALARA