NIS-general

Question 1

• What is the purpose of ACR appropriateness criteria?

Answer 1

• To assist referring physicians in making appropriate imaging decisions for given patient clinical conditions.
• Include guidelines for diagnostic imaging selection, radiotherapy protocols & Ix-guided interventional procedures.

Question 2

What is the ultimate goal of root cause analysis (RCA)?

Answer 2

• To eliminate latent errors.
• Its purpose is to evaluate serious adverse events.
  • Requires data collection, event reconstruction, record review and interviews.
  • Determines how and why the event occurred.
  • Often, adverse events are caused by multipl errors and system flaws.

Question 3

What is the most common type of error made by radiologists?

Answer 3

• Perceptual: 60-80%.
  • These are when an abnormality can be seen in retrospect, but was not identified by the interpreting radiologist at the time of initial interpretation.
  • Classic, “satisfaction of search” scenario.

Question 4

What is a congitive error?

Answer 4

• When a radiologist identifies a finding but gives an incorrect interpretation.

Question 5

1. Which contrast agent has the lowest viscosity?
2. Name 3 water-soluble contrast media.

Answer 5

1. CO₂, by far.
2. Omnipaque (iohexol), Visipaque (iodixanol), gad.

Question 6

If a pt has a Hx of anaphylactoid reaction to iodinated contrast, what agents may be used in lieu for a tube change?

Answer 6

• Gad
• CO₂ or room gas

Question 7

What is a reasonable starting dose for sedation orders?

Answer 7

• 50mcg Fentanyl: opiate/pain (typically given in IV boluses of 25-100 mcg)
• 1mg Midazolam: benzo/anxiolytic (0.5-2mg)

Question 8

What is the recommendation if a pt has CKD & gad re: NSF?

Answer 8

• Stage 1 & 2 CKD: no increased risk for NSF.
• Stage 3 CKD: NSF is exceedingly rare, so no special precautions required.
• Stage 4/5 CKD: group I gad agents are contraindicated & if it is required, group II agents should be used.
• Pts w/AKI: are at risk of NSF development & should be treated as stage 4/5 CKD pts.

Question 9

If a post-procedure pt has a HR of 40bpm & sinus bradycardia rhythm, what meds are given?

Answer 9

• Atropine 0.5 mg IV (q3-5 mins, max dose 3mg).

Question 10

Which group of gad agents has the highest # of NSF cases reported?

Answer 10

Group 1

Question 11

What are the initial IM & IV doses for epinephrine in the setting of contrast reactions?

Answer 11

Up to 1mg can be given, the initial dose is 0.1-0.3mg, which equates to the following:

IM: 1:1,000, 0.1-0.3 mL

IV: 1:10,000, 1-3 mL

Question 12

1. What is the risk of contrast reaction in pts w/unrelated allergies (food, medication)?
2. What is the recommendation re: premedication?

Answer 12

1. 2-3x the risk of an allergic-like reaction to contrast media.
2. No premedication necessary.

Question 13

What should you ask if obtaining a complete allergy Hx?

Answer 13

• What agent did the pt have a response to?
• What was the type of allergic response?
• Any other allergies, in particular, lidocaine or latex?

Question 14

1. Why are abandoned intracardiac pacemaker leads contraindicated in MR?
2. Which leads are allowed?

Answer 14

1. B/c of the antenna effect.
2. Temporary epicardial pacing leads are safe.

Question 15

Steps in dealing w/a needlestick injury?

Answer 15

• Wash the area w/soap & water immediately.
• Immediately seek care/contact the area responsible for managing occupational exposures, e.g., call the 24hr PEP line.
  • Report the incident & complete an exposure report.
  • The report should include assessment of exposure: type of fluid, needle, etc.
• Identify source patient & evaluate them for potentially transmissible diseases: HIV, HBV, HCV.
  • Source pt should undergo appropriate serological testing.
  • If this is not allowed, occupational health personnel can interview the pt to evaluate his/her risks & initiate testing.
  • Testing should be done using informed consent guidelines if the status of HIV, HBV, or HCV is unknown.
  • If the pt is not available to be tested, assessment of likelihood of infection based on the community served by the hospital.
• Any indicated antiviral prophylaxis should be initiated for the healthcare worker.
  • HIV: (risk up to 0.9%) post-exposure prophylaxis, preferably w/in hours to begin the 28-day course of retroviral drugs.
  • HBV: if healthcare work has been told they are immune after vaccination, no testing/Tx required.
• Follow-up at 72 hrs: counseling, PEP toxicity evaluation.
• Testing for the healthcare worker: timeline differs per virus, but can be at: 6wks, 3mths, 6mths, 1yr (earlier testing for HCV w/HCV RNA, Abs & ALT).
• Tx initiation should not be delayed while awaiting test results. PEP can be stopped once results are negative.
• If infection occurs, the HCW should be referred to a specialist for mgt.

Question 16

Which type of machine learning method is used for computer vision tasks?

Answer 16

Convolutional neural networks (CNNs), aka convnets

Question 17

What is the basic unit of an artificial neural network?

Answer 17

The artificial neuron, aka node

Question 18

List some applications of deep learning algorithms in radiology

Answer 18

• Mammography: breast cancer detection
• CT: segmentation of liver mets
• MRI: segmentation of brain tumours
• Chest CT: classification of interstitial lung diseases (ILDs)

Question 19

Define:

1. AI
2. Machine learning
3. Representation learning
4. Deep learning

Answer 19

1. AI: systems that perform tasks that ordinarily require human intelligence.
2. Machine learning: subfield of AI; algorithms are trained to perform tasks by learning patterns from data rather than being programmed.
3. Representation learning: type of machine learning; the algorithm learns on its own the best features to classify the provided data. The features are identified during the learning process.
4. Deep learning: a type of representation learning; the algorithm learns a composition of features that reflect a hierarchy a structures in the data. (To classify the provided data into a hierarchy.) A big benefit is that there is no need to compute features as a first step.

Question 20

List the 4 key computer vision tasks for which deep learning models have been applied

Answer 20

COSI!

1. Classification
2. Object detection
3. Semantic segmentation
4. Instance segmentation

Question 21

What is the most common form of machine learning?

Answer 21

Supervised learning

Question 22

What data sources may be used to generate machine learning labels for classification tasks?

Answer 22

1. Clinical data
2. Pathologic data
3. Rads reports
4. Expert reviews

Question 23

Radiomics trivia:

1. Define “radiomics”.
2. How does radiomics differ from deep learning?

Answer 23

1. Radiomics = the extraction of mineable data from radiologic images.
2. Radiomic features are “handcrafted”: the algorithms used to generate them are designed/chosen by the scientist rather than being learned directly from the images by the computer system.