Which scanners produce a higher mA setting, with shorter tube rotation times (of 0.5 seconds)? - ️️64 slice helical scanners
Who might require More Contrast and Faster Injection Rates (up to 6 to 8 mL/sec)? - ️️Larger patients; in order to achieve a diagnostic study
Why are both AP and L...
ASRT 140 PROCEDURE WITH
QUESTIONS
Which scanners produce a higher mA setting, with shorter tube rotation times (of 0.5 seconds)? - ✔
✔ 64 slice helical scanners
Who might require More Contrast and Faster Injection Rates (up to 6 to 8 mL/sec)? - ✔ ✔ Larger
patients; in order to achieve a diagnostic study
Why are both AP and Lateral Scouts useful in scanning the spine? - ✔ ✔ Help establish smallest
possible DFOV
Why are pts instructed to extend arms overhead in CT scans of Chest/Abd? - ✔ ✔ Prevent beam
hardening artifact
Why is Helical scan mode ideal for Chest? - ✔ ✔ -Anatomy captured in single breath hold
-Ability to post process images into thinner slices if needed
Why is Neck performed Helically? - ✔ ✔ Capture all anatomy at uniform peak contrast enhancement
Why is slice thickness reduced through Posterior Fossa for Head? - ✔ ✔ To reduce beam hardening
artifact caused by petrous pyramids
Why is the Right AC vein more favorable than the Left for a CTA Study? - ✔ ✔ Bolus of contrast can
reach the right side of heart quickly before traveling to the lungs
Why might pre and post contrast scan be in protocol for Neck? - ✔ ✔ Differentiate tumors/ abcesses
from normal anatomy
Why should pts be instructed to maintain good hydration following exam? - ✔ ✔ Assist Kidneys in
filtering the contrast out of bloodstreem
Why would some departments have a protocol that can inferiorly to superiorly for CTA Chest? - ✔ ✔
To catch distal pulmonary arteries at peak enhancement if the scanner is slower.
3D Volume Rendering /Shaded Surface Display produces high quality images that clearly show the
relationships between _____. - ✔ ✔ between hardware, bones, and bone fragments.
Complex injuries are best demonstrated with _______ - ✔ ✔ 3D Volume Rendered/Shaded Surface
Display
Contrast Administration Abdomen/Pelvis - ✔ ✔ Volume- 100 to 150 mL
,Injection Rate- 2 to 3 mL/sec
Scan Delay- 65 to 75 seconds. 90 seconds for PELVIS ONLY
Contrast Administration CTA Abdomen Pelvis - ✔ ✔ Reference Location- Smart prep 2cm above area
of interest in Descending Aorta
Threshold- 125 to 150 HU
Post Threshold Delay- 3 to 5 seconds
Contrast Volume- 100 to 125 mL
Injection Rate- 4mL/sec
Saline Chaser- 30 to 50 mL (push bolus and reduce beam hardening artifact)
CT Urography Indications? - ✔ ✔ -Renal Stones,
-Renal Parenchymal Masses,
-Urothelial Abnormalities
Example Protocol for CT Enterography - ✔ ✔ 450mL 60 minutes before scan
450mL 45 minutes before
450mL 30 minutes before
500 to 600 mL waater prior to scanning
0.2 to 0.5 mg of Glucagon may be given 5 to 15 mins prior to exam through IV to reduce Peristaltic
Artifact
IV- 140 mL Iohexol injected at 4mL/sec
Scan Delay of 50 seconds
Slice thickness- 2 to 2.5mm
Reconstruction Interval- 1 to 1.5mm
, Examples of Protocols for CTA Chest POST PROCESSING (PE vs Thoracic) - ✔ ✔ PE (Axials in both lung
and mediastinal windows, and Oblique Series of each Pulmonary Artery and Lung)
Thoracic Aorta (AP, Lateral, Oblique Sagittal MIP, 3D Rendering of the Aorta)
High Spatial Frequency (Bone) Algorithm - ✔ ✔ Lung window- Display lungs and their air filled spaces
WW 1500
WL -500 to -600
High Spatial Frequency Algorithm CTA Chest - ✔ ✔ WW 1500
WL -500 to -600
Displays lungs and air filled spaces
How are CT Arthrograms reformated? - ✔ ✔ 2D MPR in the three standard planes
(no 3D MPR is needed)
How do the detectors affect pitch? - ✔ ✔ Pitch can be dependent on
-Detector configuration
-Number of Detectors & Detector rows sampled for Image Reconstruction
How is Head positioned? - ✔ ✔ Tuck chin comfortably to
-Bring OML parallel to Axial Scan Plane.
-Align laser laterally at level of EAM
-Zero laser at Mental Point (for caudocranial protocol)
-Zero laser at top of head (for craniocaudal protocol)
How is routine head conventionally acquired? - ✔ ✔ Axial Mode
How long after drinking Oral Contrast should a pt be scanned? - ✔ ✔ A delay of at least 45 minutes,
to allow the entire GI tract to be fully opacified.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller jackline98. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.99. You're not tied to anything after your purchase.
