LESI LESI Fluoroscopy and Imaging Guidance 2

Question 1

Digital subtraction angiography (DSA) during transforaminal LESI offers what advantage over standard fluoroscopy?

Accepted Answer

It enhances detection of intravascular contrast uptake by subtracting the bony background

Answer

DSA subtracts the static bony fluoroscopic image, leaving only contrast flow visible, which makes small volumes of intravascular contrast uptake far more detectable than with standard fluoroscopy.

Question 2

Which imaging modality is used for LESI guidance when fluoroscopy is contraindicated (e.g., pregnancy)?

Accepted Answer

Ultrasound guidance

Answer

Ultrasound guidance avoids ionizing radiation and can be used for lumbar ESI when fluoroscopy is contraindicated, particularly in pregnancy, using real-time visualization of the ligamentum flavum and epidural space.

Question 3

The 'loss of resistance' technique during ESI uses which substance to confirm epidural entry?

Accepted Answer

Air or preservative-free normal saline

Answer

The loss of resistance technique uses air or preservative-free saline in a syringe; the plunger meets resistance in the ligamentum flavum and suddenly loses resistance as the needle enters the epidural space.

Question 4

A posterior epidural spread pattern without filling of nerve root sheaths on fluoroscopy after interlaminar injection suggests which problem?

Accepted Answer

Needle tip in the posterior epidural fat only without adequate anterior spread toward the nerve root

Answer

Posterior-only contrast spread without anterior flow toward nerve root sleeves suggests the needle may be too posterior, limiting injectate access to the target anterior epidural space where nerve roots are located.

Question 5

Radiation dose reduction during fluoroscopic LESI can be achieved by all of the following EXCEPT:

Accepted Answer

Increasing distance between the image intensifier and the patient

Answer

Increasing the distance between the image intensifier and the patient actually increases radiation dose to the patient; the intensifier should be kept as close to the patient as possible to minimize dose.

LESI - Lumbar Epidural Steroid Injection Practice Test

LESI - Lumbar Epidural Steroid Injection Practice Test

LESI LESI Fluoroscopy and Imaging Guidance 2