Enteric Contrast Media for Pediatric Imaging
Michael J. Callahan, M.D. Department of Radiology Boston Children’s Hospital Associate Professor of Radiology Harvard Medical School What is a contrast medium? Contrast Medium
In the context of medical imaging:
– Substance used to enhance the “contrast” of certain structures or fluids within the body
Contrast Media
• Vascular • Enteric • Cavity • Joint • CNS
Enteric Contrast Media
• Fluoroscopy – X-ray attenuation
• CT – X-ray attenuation
• MRI – signal intensity
• Ultrasound – attenuation coefficient
Enteric Contrast Media
• Advantages – (Potentially) improves diagnosis – (Potentially) increases dx accuracy – Allows for use of fluoroscopy • Disadvantages – Time – Cost – Adverse or allergic-like reactions
Outline
• Fluoroscopy • Ultrasound • Computed Tomography • MRI • Shortages
Outline
• Fluoroscopy • Ultrasound • Computed Tomography • MRI • Shortages
Fluoroscopy
• Established ACR guidelines for enteric contrast media for adults
• “Special considerations” in children
• Fluid shifts, hyperosmolar media
• Aspiration pneumonitis
Fluoroscopy
– Versatile
– High or low scatter environments
Fluoroscopy
• Barium Sulfate
– Suspension – Oral, transesophageal catheter, gastrostomy, jejunostomy, ileostomy – Cecostomy, colostomy, mucous fistula – NOT used for enemas at BCH – Limited in setting of suspected perforation
Fluoroscopy
• Iodine-based – Water soluble – IOCM, LOCM, HOCM – Ionic and non-ionic
– Bitter taste – Expensive
Fluoroscopy • Iodine-based water-soluble as enteric media – Version 10.3 (2017) of the ACR Manual on Contrast Media, pg 60.
• (Any) “iodinated contrast media supplied for intravenous use also can be administered safely by mouth or per rectum”.
• “Enteric use is generally “off label”, with the exception of Iohexol (Omnipaque, GE Healthcare; Princeton, NJ) which has an FDA-approved indication for oral use in select concentrations”
Technical considerations
20 cm
Large 5 cm Adult
Small Child
5 cm 20 cm Barium Sulfate vs IBCM
Case Examples 5-month-old female with LGEA rule out leak
OPTIRAY 240
19-year-old female morbid obesity
OPTIRAY 320
Post op UGI OPTI 320 2-day-old with bilious emesis
Cysto-Conray II vs. BARIUM 2-day-old male, bilious emesis US
CT
MRI Outline
• Fluoroscopy • Ultrasound • Computed Tomography • MRI • Shortages
Ultrasound
• Air has a higher attenuation coefficient relative to soft tissue or fluid
• Air reflects sound waves
Ultrasound
• Reflection occurs at a boundary of 2 materials with different acoustic impedances
Normal Pylorus Antrum
DB 4-day-old boy with vomiting. Soft tissue mass at gastric outlet
B 4-day-old boy with vomiting. Soft tissue mass at gastric outlet
A Outline
• Fluoroscopy • Ultrasound • Computed Tomography • MRI • Shortages
Is enteric CT contrast necessary ? CT • Variable opinions on need of enteric contrast media for pediatric CT abdominal imaging
2017 2015
2011 2016 CT: Is enteric contrast (really) necessary ? • No
• Can be helpful in children w paucity of retroperitoneal and intraperitoneal fat, increased image noise • ?? Anesthesia
CT enteric contrast Yes • Oncology • Suspected intra-abdominal abscess • Abdominal pain NOS No • Suspected acute appendicitis • Trauma • Suspected renal stones • CT angiography
CT
• Dilute Iodine- based or dilute barium-based media
Optiray 320 enteric CT prep
• Dilute 1 mL Optiray 320 into 30 mL of clear liquid
• Age-adjusted doses • 90 minutes prior to study • 30 minutes “ “ • Just prior to study CT enteric media
Abdomen
A = Air B B = Optiray 320
C = Dilute Optiray 320 A C (30:1) Bone
B
A C • 15-year-old female with left sided abdominal pain, fever and vomiting US, 10/16/16 CT, 10/17/16 CT, 10/17/16 • Diagnosis: Mesenteric cyst vs. LM • Drainage by IR • Ruptured, resulting in hypotension and ICU stay • Discharged w tumor markers sent • Back to ED 10 days later, abdominal pain
MRI, 11/2/16
• 11/7/17 OR • Small Round Blue Cell tumor
Barium sulfate suspension
A B
Single detector CT, 2003 Optiray 240
10 y.o. male, G-tube check KUB next day, CT requested Optiray 240
Optiray 240 Optiray 320, diluted 30:1
Modern MDCT, 2018 CTE
• PEG (MiraLAX), • Psyllium (Metamucil) • Dilute barium suspension (VoLumen)
Outline
• Fluoroscopy • Ultrasound • Computed Tomography • MRI • Shortages
MR Enterography (MRE)
• Similar oral prep as CTE
• PEG (MiraLAX), Psyllium (Metamucil), Dilute barium suspension (VoLumen)
PEG (MiraLAX) oral prep
• Poly ethylene glycol
• Doses • < 25 kg = 2 packets • 25-50 kg = 3 packets • > 50 kg = 4 packets AX VIBE FS post gad
A
Optimal enteric prep
B
Patient refused enteric prep
MRCP
MRCP Cor 3-D MRCP sequence
Nature’s Place Organic True Blue Blueberry Walgreen’s Distilled Water Blueberry Juice Juice A
AJ H2O
B
AJ H2O A
B Pre BBJ Post BBJ 16-year-old female w recurrent pancreatitis. Small pseudocyts (asteriks) in the pancreatic tail are well delineated by BBJ in stomach and jejunum Outline
• Fluoroscopy • Ultrasound • Computed Tomography • MRI • Shortages
Contrast shortages Shortage
• 1 part Optiray 320 and 3 parts saline • Similar iodine content CC-II • Lower osmolality • Time
CC-II = 81 mg/ml iodine • $$
Shortage Shortage
H2O PJ Take Home Points Take Home Points
• Enteric contrast can be an important component for certain pediatric imaging studies • Knowledge of basic concepts is key for effective utilization
Take Home Points
• Certain beverages or over-the- counter medications can be used as contrast media for CT, MRI and US
Antrum
DB B