LESI Study Guide 2026

Everything you need to pass the LESI exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.

📋 LESI Exam Format at a Glance

60
Questions
90 min
Time Limit
70.00%
Passing Score

📚 LESI Topics to Study (23)

✍️ Sample LESI Questions & Answers

1. Which psychiatric medication requires special consideration before LESI due to potential for severe hypertensive crisis with epinephrine-containing test doses?
Monoamine oxidase inhibitors (MAOIs)

MAOIs inhibit the metabolism of catecholamines; use of epinephrine-containing solutions in patients on MAOIs can trigger a severe hypertensive crisis.

2. A disc herniation at L5-S1 most commonly compresses which nerve root?
S1 nerve root

A paracentral or posterolateral disc herniation at L5-S1 typically compresses the traversing S1 nerve root.

3. The Knees are flexed during the AP Lumbar Spine to flatten the natural ________________________ curve of the spine.
Lordotic

During the AP Lumbar Spine, the knees are flexed to flatten the natural lordotic curve of the spine. The lordotic curve refers to the inward curve of the lower back. By flexing the knees, it helps to reduce the curvature of the lower back and create a more flattened position for the lumbar spine during the imaging procedure. This positioning allows for better visualization and assessment of the lumbar vertebrae and their alignment.

4. During transforaminal LESI setup, the C-arm is obliqued ipsilaterally until which classic landmark is visualized?
The 'Scotty dog' silhouette of the vertebra with the pedicle as the eye

The oblique view creates the 'Scotty dog' appearance where the pedicle represents the eye; the needle targets the inferior aspect of this eye (the superior foramen) for safe entry.

5. The caudal epidural approach accesses the epidural space through which anatomical opening?
The sacral hiatus at the base of the sacrum

The sacral hiatus is a midline opening at the inferior end of the sacral canal formed by non-fusion of the S4-S5 laminae and is the entry point for the caudal approach.

6. The epidural space in the lumbar region is located between which two structures?
The dura mater and the ligamentum flavum

The lumbar epidural space lies between the dura mater anteriorly and the ligamentum flavum posteriorly.

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Your LESI Study Path
1. Learn with Flashcards → 2. Drill Practice Tests → 3. Take the Full Exam Simulation
LESI Study Guide 2026 — Exam Format, Topics & Practice Questions