How to Scan a Lumbar Spine MRI Protocol

Are you looking to improve your lumbar spine MRI skills?

The lumbar spine MRI protocol is crucial for diagnosing and managing common back issues, including pain, trauma, and neurological symptoms.

This step-by-step guide is for MRI students and technologists who wish to improve their professional skills and master the lumbar spine MRI protocol.

What you will learn:

1. What key factors to consider in lumbar spine MRIs, and how to think when facing trade-offs.
2. How to set up the patient and scanner.
3. What pulse sequences to use, and how to plan them.
4. How to avoid the common lumbar spine artifacts.
5. What good lumbar spine images should look like.

The lumbar spine is the lower part of your spine. It’s the backbone of our movement and support, literally. It carries much of our body weight, enables flexibility for bending and twisting, and protects critical nerves controlling the lower body.

This lower back area is a common source of pain and neurological conditions — which is why the lumbar spine study is one of the most highly requested protocols in MRI.

How to Balance the 3 Trade-offs in Lumbar Spine MRIs

In MRI, we always face a trade-off between 3 key metrics:

1. Scan Time: How fast a pulse sequence can be completed.
2. Resolution: How much detail the image can display.
3. SNR: How clear the image is, i.e. how much signal relative to noise.

Improving one of these metric reduces the performance of the others. To decide what trade-offs to make, we must consider the needs of each clinical situation.

For lumbar spine MRIs: It is one of the most highly requested protocols, and requires enough resolution and SNR to meet your institution’s guidelines.

Therefore, you may want to slightly prioritize scan time over resolution and SNR in lumbar spine MRIs. This helps you complete all the incoming requests in time. Shorter scan times also ensure more consistent and reproducible images by reducing patient motion during the scan.

Lumbar Spine Health Conditions – and the MRI Sequences That Detect Them

The lumbar spine MRI study can help us diagnose a wide range of health conditions. The table below lists some of the most common conditions — and what pulse sequences that detect them:

The step-by-step guide below will show you how to set up and perform a lumbar spine MRI protocol in practice.

We will perform the protocol in 3 parts:

1. Set up the Patient and MRI Scanner
2. Plan and Acquire the Protocol Sequences
3. Review the Images

Part 1: Set up the Patient and MRI Scanner

1. Position the Patient in the Scanner

Lay the patient feet-first and supine (on their back) with the lumbar region aligned at the scanner’s isocenter.

Using a feet-first position makes the scan feel less claustrophobic for the patient, which reduces the risk of motion artifacts.

Place a dedicated lumbar spine coil at the patient’s back. This coil ensures you get full coverage of the lumbar region and delivers strong signal acquisition for clear images.

✅ Correct Patient Positioning:

2. Check the Scanner’s Hardware Settings

Once the patient is in place, review your scanner’s hardware settings.

We recommend using the following settings:

This hardware setup is widely used in clinical practice. It balances acquisition time, image quality, and patient comfort.

3. Capture the Initial Localizer Images

Before we can perform any MRI protocol, we must always capture initial localizer images of the patient. These images act as a guide for planning the detailed scans we will perform next.

We should always capture localizers in three planes:

1. Axial
2. Sagittal
3. Coronal

Once acquired, upload the initial localizer images into the three viewports.

Then, scroll through each of the image stacks to locate a central slice that clearly shows the anatomy of the lumbar spine.

✅ Correct Setup of Localizer Images for Lumbar Spine MRI:

Part 2: Plan and Acquire the Protocol Sequences

When all preparations are ready, we can start planning and acquiring the protocol sequences.

Let’s go through the pulse sequences that a standard lumbar spine MRI protocol includes, why we perform them, and how to set them up.

The 6 Sequences of a Standard Lumbar Spine MRI

1. Coronal T2 TSE
2. Sagittal T2 TSE
3. Sagittal STIR TSE
4. Sagittal T1 TSE
5. Axial T2 TSE, Multi-Block and Multi-Angle
6. Axial T1 TSE, Multi-Block and Multi-Angle

We mainly use Turbo/Fast Spin Echo sequences because they let us create image contrasts in T2 and T1-weighting, as well as inversion recovery for fat suppression. These contrasts help us to assess the integrity of the lumbar spine and check for common pathologies. Using Turbo Spin Echo sequences also keeps the scan time short.

In the sections below, we go through how to plan and set up each sequence.

1. Coronal T2 TSE

✅ Correct Planning:

Planning Instructions:

• Use the spinal cord as a reference point.
• Ensure the slices cover all 5 intervertebral discs: L1-L2, L2-L3, L3-L4, L4-L5, and L5-S1.
• Align slices as follows:
  • Axial Localizer: Parallel to the transverse processes of the lumbar vertebrae.
  • Sagittal Localizer: Parallel to the spinal cord to ensure anatomical accuracy.

Parameters for Coronal T2 TSE:

2. Sagittal T2 TSE

✅ Correct Planning:

Planning Instructions:

• Use the spinal cord as the main anatomical reference.
• Ensure slices extend from the last two thoracic vertebrae (T11 and T12) at the top of the spine, down to the sacrum (S1) at the bottom of the spine.
• Align slices as follows:
  • Axial Localizer: Symmetrical to the vertebral bodies.
  • Coronal Localizer: Parallel to the spinal cord.

Parameters for Sagittal T2 TSE:

3. Sagittal STIR TSE

✅ Correct Planning:

Planning Instructions:

• Copy the slice geometry and planning directly from the sagittal T2 sequence.
• Maintain identical slice angulation, coverage, and positioning to get precise comparison between T2 and STIR images.

Parameters for Sagittal STIR TSE:

4. Sagittal T1 TSE

✅ Correct Planning:

Planning Instructions:

• Copy the slice geometry and planning directly from the sagittal T2 sequence.
• Maintain identical slice angulation, coverage, and positioning to get precise comparison between T2 and T1 images.

Parameters for Sagittal T1 TSE:

5. Axial T2 TSE, Multi-Block and Multi-Angle

✅ Correct Planning:

Planning Instructions:

• Use multi-angle and multi-stack techniques to ensure precise alignment and full coverage of each intervertebral level.
• Align slices parallel to each of the 5 lumbar intervertebral spaces: L1-L2, L2-L3, L3-L4, L4-L5, and L5-S1.
• Use the coronal view to center slices left-to-right across the vertebrae.
• Use the sagittal view to center anterior-to-posterior and ensure slices are parallel to the intervertebral discs.
• For each intervertebral space:
  • Adjust the plane orientation and slice angulation to align closely with the disc plane.
  • Center slices between the spinal cord and the intervertebral disc, ensuring proper coverage of the vertebrae and surrounding structures.
• Artifact Prevention:
  • Verify slice angulations across stacks to avoid cross-talk artifacts, particularly at the lumbar spine’s posterior aspect.
  • Minimize slice overlap while maintaining full coverage of the edges and central regions of each intervertebral space.

Parameters for Axial T2 TSE:

6. Axial T1 TSE, Multi-Block and Multi-Angle

✅ Correct Planning:

Planning instructions:

• Copy the slice planning and geometry from the axial T2 sequence to maintain identical alignment.

Parameters for Axial T1 TSE:

How to Avoid Artifacts When Planning the Sequences

The table below lists the 5 common lumbar spine artifacts, and what techniques you can use to avoid them:

Part 3: Review the Images

Finally, we will review the images to ensure all the anatomical information we need is clear.

These key structures must be clearly visible in a lumbar spine MRI:

1. Spinal cord and cauda equina
2. The 5 lumbar intervertebral discs, and the body and posterior process of each disc
3. Nerve roots
4. Ligaments
5. Surrounding structures, including paraspinal muscles and epidural space

Below, we will go through all the different image contrasts and explain their specific role in imaging the lumbar spine.

T2 TSE – Highlight Fluid-Related Tissues and Conditions

T2-weighted imaging makes fluid appear bright and fat dark. This contrast is ideal to detect abnormalities associated with high water content.

In the lumbar spine, T2 images especially help us view the spinal cord, cerebrospinal fluid (CSF), intervertebral discs, and any fluid-related pathology. Hydrated discs, cysts, or areas of inflammation appear bright, helping us detect conditions like disc degeneration, herniation, and spinal stenosis.

T2 also excels at visualizing nerve root impingement, synovial cysts, and perineural edema — as well as soft-tissue injuries like torn ligaments and tendons.

✅ Axial T2 of Lumbar Spine – Correct Image:

Axial T2 focuses on cross-sectional details of the spinal canal and neural foramina. By using multi-block and multi-angle acquisitions to align with each intervertebral disc, we can capture nerve root compression, foraminal narrowing, and lateralized disc herniations.

✅ Sagittal T2 of Lumbar Spine – Correct Image:

Sagittal T2 reveals a longitudinal view of the spine, allowing for assessment of overall alignment, hydration of discs, and the degree of spinal stenosis or nerve root compression.

✅ Coronal T2 of Lumbar Spine – Correct Image:

Coronal T2 gives a wide perspective of the spine's alignment, identifying coronal plane pathologies such as scoliosis, lateral disc herniations, or ligamentous abnormalities.

T1 TSE – Highlight Fat-Containing Tissues and Structural Abnormalities

T1-weighted imaging makes fat appear bright and fluid dark. This contrast is ideal for fat-rich tissues and abnormalities. Because fat is solid and well-defined, anatomical structures become clearer in T1 – as we can easier see where different solid tissues, like muscle and fat, meet.

In the lumbar spine, this contrast is ideal for assessing bone marrow, epidural fat, and the integrity of vertebral bodies. Chronic degenerative changes, such as Modic endplate changes, fractures, or tumors, are more apparent with T1 imaging because of its ability to differentiate fat from other tissues.

✅ Axial T1 of Lumbar Spine – Correct Image:

Axial T1 focuses on detailed anatomy at the level of the spinal canal and foramina. By using multi-block and multi-angle acquisitions to align with each intervertebral disc, we can visualize foraminal narrowing and chronic degenerative conditions.

✅ Sagittal T1 of Lumbar Spine – Correct Image:

Sagittal T1 provides a midline view, showing vertebral bodies, intervertebral discs, and chronic bony changes. It complements sagittal T2 by offering a clearer view of bone marrow and structural abnormalities.

STIR TSE – Clearest View of Fluid-Related Tissues and Conditions

STIR (Short Tau/TI Inversion Recovery) suppresses fat signals completely, which makes water-rich tissues stand out even clearer than with normal T2 TSE. This makes STIR ideal for detecting subtle fluid-related conditions — like edema, inflammation, and infections — where increased water content would otherwise be obscured by fat.

In the lumbar spine, this contrast is particularly useful for identifying bone marrow edema and infections like discitis or myelitis. STIR is also crucial for detecting inflammatory conditions where water content might not be visible on standard T2 sequences.

✅ Sagittal STIR of Lumbar Spine – Correct Image:

The STIR sequence’s main purpose is to detect edema and inflammation, which is best seen in the sagittal plane. This lets us view the entire spine so we don’t miss any fluid-related changes across vertebrae or discs.

Final Checks:

• Ensure the field of view covers all relevant anatomy.
• Verify that contrast, resolution, and signal-to-noise ratio meet your clinical requirements.

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