Transcript Introduction to Radiology - UNC School of Medicine

INTRODUCTION TO
RADIOLOGY
Casey Sams, MD
Introduction to Radiology
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I: Radiology
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Who we are
What we do
Our tools
How can you help us help you
II: Contrast
III: Plain Film Imaging of the Abdomen
IV: Radiology at UNC
V: Parting Thoughts
Definition of Radiology
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Radiology is a medical
specialty using medical
imaging technologies to
diagnose and treat
patients.
So what does this mean?
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We do NOT spend all day in a small dark room
staring at a computer screen
….just most of the day
A widely varied discipline
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Read a chest x ray
Stage lymphoma
Do a TIPS procedure
Do a biopsy (lung, bone, thyroid, breast…)
Inject a joint
Do a barium swallow
With multiple subspecialties
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Breast
Body
Neuro
MSK
Peds
IR
What our are tools?
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X-rays
CT
MRI
Ultrasound
Nuc Medicine
Fluoroscopy
Mammography
Conventional Radiography “X-Ray”
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Lingo:
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Density
Opacity
Observable Densities:
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Metal
Bone
Soft Tissue
Gas
Computed Tomography (CT)
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Lingo:
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Hounsfield Units
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Attenuation
Density
Enhancement
-1000 air ***
-100 fat
0 water ***
20-80 soft tissues
100’s bone/Ca/contrast
>1000’s metal
Large radiation dose
Nuclear Medicine (NM)
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Lingo:
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Physiologic imaging
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Radionuclides
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(Technetium)
Radiopharmaceuticals
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Counts or Activity
(Choletec)
Radioactivity stays with the
patient until cleared or
decayed
Ultrasound
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Lingo
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Echogenicity
Shadowing
Doppler for flow
No radiation
Can be portable
Relatively inexpensive
Magnetic Resonance Imaging (MRI)
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Lingo:
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No radiation
Strong magnetic field
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Signal intensity
T1
T2
Enhancement
No pacemakers
No electronic implants
Small, loud tube
Patients must hold still
Relatively expensive
Fluoroscopy
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Lingo
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Filling defect
Density
Opacity
Real time information
Radiation dose dependent
on length of exam
http://www.med-ed.virginia.edu/courses/rad/gi/index.html
Mammography
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http://www.mdgrant.com/images/NormalMammogram.jpg
Lingo
 Microcalcifications
 Mass
 Asymmetric
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density
Screening exam consisting of 2 views recommended
yearly for women over 50
We still recommend it!
When will you interact with Radiology?
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Anytime you read a report on a study
As a part of rounds (critical care and ID rotations in
particular)
When we call you up to ask about more information
before we do a study
When you call us to ask about which study should
be done
And if you want more…
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Rad 401 elective is a great way to get a broad
introduction to radiology. Very helpful for people
not interested in pursuing a career in radiology
(plus those who are!)
Pediatric radiology rotation
Neuroradiology rotation
Choose your own adventure….
How can you help us help you?
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Indication, indication, indication
How will this study impact your clinical decision
making? If it won’t, perhaps its useful to rethink the
need for the study.
Become adept at how to read basic studies (chest
and abdominal films for line and tube placement in
particular)
Why is indication so important?
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It provides a paradigm for the picture we are
reading.
More information will help tailor the report to your
clinical question.
Depending on the indication, the hospital may not
be reimbursed for the study
GOOD
BAD
dyspnea in cancer patient
R/O PE
abdominal pain in Crohn’s
patient s/p SB resection
R/O pain
Pain over dorsal aspect of trauma
hand
Contrast
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Oral contrast is frequently used in CT of the
abdomen and pelvis and is very safe
There are 2 types of intravenous contrast.
 Iodinated
contrast for CT
 Gadolinium based contrast for MRI
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Radiologists like contrast !!
BUT
Contrast is not without risks
Allergic Reactions to iodinated contrast
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Can range from mild to severe (hives to
anaphylaxis)
If mild allergic reaction, can pretreat with
prednisone (50mg administered 13, 7, and 1 h
prior to scan + Benadryl 1 hour before the scan)
If severe allergic reaction, contrast is
contraindicated!
Iodinated contrast and renal failure
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Contraindicated in renal failure (acute and chronic) because of
risk of contrast induced nephropathy (CIN); Strict UNC cut off is
Cr of 1.8.
Avoiding contrast in the setting of acute renal failure is important,
but it is difficult for the radiologist, because the creatinine may
be normal. (ie <1.8)
In hyper-acute renal failure, the creatinine hasn’t risen yet.
Decreased urine output or anuria is acute renal failure –
regardless of the creatinine.
Remember; first do no harm! Non-contrast studies can often be
quite helpful.
MR Contrast and NSF
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Risk of nephrogenic
sclerosing fibrosis (NSF)
increases with decreasing
GFR; contraindicated <30
Progressive fibrosis of skin in
patients with renal failure
(typically on dialysis) which
result in painful contractures
and, possibly, death.
http://jama.amaassn.org/content/vol297/issue3/images/medium/jmn60162fa.jpg
Reading an abdominal film
Where can you look at images
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PACS workstations
 ED
 ICUs
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WebCIS based PACS (java script)
Web Based PACS
Basics:
Looking at Imaging Studies:
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Adequate Study?
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Correctly labeled with patient’s name, MR#, and the date of the
study?
Technically adequate?
Systematic versus Focused look at a study:
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Radiologist does both!
As the requesting clinician, you should also look at your patient’s
study (at least plain films), as well as follow up on the final
report.
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PTX, PNA, pleural effusions, SBO, free air
Evaluate lines and tubes (especially the ones you placed!)
Several different type of abdominal film
series
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KUB (kidneys, ureter, bladder)
2 View---AP supine and erect abdomen
Acute abdomen series: 2 view with upright chest
Lateral decubitus (Left or Right)
Cross table lateral---prone or supine
Systematic process
• Lines and tube (enteric tube,
feeding tube, foley catheter,
rectal tube, fem lines)
• Bowel gas pattern (dilated
loops, air where it shouldn’t
be)
• Visceral contours
(hepatomegaly, abnormal
soft tissue mass)
•Abnormal calcifications
(gallstones, kidney stones)
• Bones
Enteric tube (NG/OG) placement
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Tip AND sidehole need to be within the stomach
body for proper suction
REALLY BAD – enteric tube in lung
http://icvts.ctsnetjournals.org/content/vol4/issue5/images/large/429fig1.jpeg
Small Bowel Obstruction (SBO)
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Gasless abdomen if bowel loops are fluid filled
Dilated small bowel loops (>3cm)
Sometimes difficult to differentiate between SBO
and ileus (both colon and small bowel tend to be
dilated)
http://archive.student.bmj.com/issues/02/04/education/102.php
Paucity of gas
CT correlate: SBO
Dilated loops of small bowel
CT correlate: more gas, & SBO
Pneumoperitoneum
Pneumoperitoneum
Abnormal calcifications: Gallstones
supine and erect
Air-fluid levels
CT correlate: Gallstones
Abnormal Calcifications: Nephrolithiasis
CT correlate: Nephrolithiasis
Abnormal calcifications: Appendocolith
http://www.hawaii.edu/medicine/pediatrics/pemxray/v6c18.html
Plain film imaging of the Abdomen: Bones
http://www.szote.u-szeged.hu/radio/trauma2/a2trau3a.htm
Radiology at UNC
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The Department of Radiology at the University of North Carolina at
Chapel Hill has eight clinical sections:
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Abdominal Imaging (Body CT, US, MRI, Flouro studies such as UGI and
SBFT, Biopsies)
Breast Imaging
Cardiopulmonary Imaging (Chest, Cardiac)
Musculoskeletal Imaging (Bone, ER RR, MSK MRI’s)
Neuroradiology (brain/spine CT & MRI; lumbar punctures)
Nuclear Medicine (wide variety, PET-CT, bone scans, Cards)
Pediatric Imaging (wide variety)
Vascular-Interventional (wide variety)
Calling Radiology
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Try to call the right reading room (RR).
 Each subspecialty has their own reading room
 Calling the Neuro reading room to talk about a chest x ray will
not get you far (like asking ENT to perform an appendectomy)
When paging, it’s nice to put your name/pager number immediately
after the call back number
After hours:
 6-8850 Lower Level/ER RR
 216-2826 Upper Level (VIR, Doppler US, MRI)
DON’T call 6-8850 during the day
 unless it’s an MSK radiology issue
When you call, identify yourself, and expect whoever answers to
identify themselves.
 Improves accountability
 Always good policy to know who talked to
Please page us if our report is confusing!
Parting thoughts (for Radiology and
beyond!)
Always try to be polite. This will be difficult
when you are sleep deprived and overworked,
but “please” and “thank you” go a long way in
maintaining cordial relationships with your coworkers.
 Try to resist the urge to “bad mouth” other
specialties.
 Speak up when you see something wrong!
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RECAP
o Radiology is a cool specialty. Think whether it’s a good
fit as you go through the year.
o CT is a great tool but provides a high does of
radiation
o Provide good indications!
o IV Contrast + Sick Kidneys = BAD
o If worried about free air in the abdomen, order
upright or decubitus films
Thanks for listening! Questions?
Hx: Please
Evaluate
New Line.
“?!@#!%!”