If your lower back hurts, is an MRI absolutely necessary?

MRI is an important examination that can carefully examine the disc, nerves, and spinal canal.

However, not all patients need to undergo an MRI simply because they have back pain or slightly numb legs.

Many common cases of lower back pain can have their initial treatment direction determined through a detailed history taking and physical/neurological examination. MRI is considered when there are warning signs, symptoms continue to worsen, or examination results will change treatment decisions such as injections and surgery.

• Degeneration, protrusion, and extrusion of the disc
• Compression of the lumbar nerve and nerve bundle
• Narrowing of the spinal canal and the passages through which nerves exit
• Abnormalities of the vertebral bones and bone marrow
• Some fractures and soft tissue changes
• Changes suspected to be infection or tumor
• Scars and recurrent lesions after surgery

MRI provides a lot of information, but not all changes visible on the images may be the cause of current pain.

Changes in urination and defecation, and sensation in the perineal region

This is a case where urination suddenly becomes difficult or hard to hold back, and sensation in the perineum and inner buttocks becomes dull.

If leg muscle strength decreases rapidly

This occurs when it is difficult to lift the ankle or toes, when the foot drags, or when gait suddenly becomes unstable.

Severe symptoms in both legs

This is a case where severe pain, numbness, and sensory changes suddenly appear or progress in both legs.

Such symptoms may require a rapid MRI and specialist consultation to determine whether there is severe nerve compression.

In cases with the following symptoms and history, it must be distinguished from general lower back pain.

• high fever and chills
• Recent severe infection or surgery
• Immunodeficiency
• History of cancer
• Weight loss that is difficult to explain
• Nocturnal pain that continues to worsen even with rest
• Severe generalized weakness

No one symptom alone confirms a diagnosis, but an MRI and additional tests may be needed depending on the healthcare professional’s assessment.

The decision to have an MRI is not based solely on how long symptoms have lasted.

In the following cases, MRI results may affect the treatment plan.

• If leg pain and numbness persist despite appropriate treatment
• If neurological symptoms gradually worsen
• When considering injections or surgery
• When it is necessary to structurally confirm the current symptoms and nerve examination results
• If new symptoms appear that cannot be explained by the existing diagnosis

Do not unconditionally order imaging studies simply because pain has persisted for a long time, nor should you delay necessary examinations merely on the grounds of being young.

That is incorrect.

Disc herniation and degenerative changes can also occur in people without pain.

The MRI results should be reviewed in conjunction with the following.

• The actual location where pain and numbness occur
• Leg muscle strength and sensation
• Knee and ankle reflex
• Walking and daily activities
• Whether symptoms are improving or worsening
• Whether the nerve area visible on the imaging matches the actual symptoms

Even if the MRI report mentions “protrusion,” “extrusion,” or “stenosis,” symptoms and function must also be assessed.

No.

MRI cannot show all of the following.

• In which movement does pain occur?
• How much the lower back and pelvis actually move
• Whether the muscles are exerting force at the appropriate moment
• How is your ability to sit for long periods and walk?
• What effects do activity level and sleep have on pain?

Even if no serious abnormalities are detected on MRI, pain and restricted movement may occur due to problems with muscle and joint function.

Medical History Taking

We check the onset and cause of pain, leg symptoms, and warning signs.

Movement of the lumbar spine and pelvis

We examine how pain and restriction manifest during flexion, extension, and rotation.

Muscle strength and sensation

Compares the strength of the ankle and toes, as well as sensation in the legs and feet, between left and right.

Reflexes and Gait

We check the reflexes of the knee and ankle, walking on heels and toes, and whether the foot drags.

Daily Function

We assess how long you can sit and walk, and whether you can climb stairs and lift objects.

If no red flags are found in these examinations and the condition appears to be a typical musculoskeletal issue, initial treatment can begin without MRI while monitoring the course of the condition.

Conversely, if muscle weakness and warning signs are identified, you may first guide the patient to undergo an MRI and collaborate with relevant specialists.

• Pacemaker and implantable medical devices
• Cochlear implant
• Cerebrovascular clip
• Metal objects after surgery
• History of accident with a metal fragment embedded
• Pregnancy or possibility of pregnancy
• Kidney disease
• Contrast agent hypersensitivity reaction
• Severe claustrophobia
• Pain that is difficult to endure while lying down for a long time

Some medical devices may allow for MRI under certain conditions; therefore, you must inform the medical staff about the device information and surgical records.

When checking for common disc herniation and stenosis, MRI without contrast agent is often considered.

If infection or tumor is suspected, or when distinguishing between postoperative scars and recurrent lesions, the use of contrast agents may be considered.

You must inform us about your kidney function and any previous adverse reactions to contrast media before the procedure.

The two examinations look at different things.

X-ray

It confirms the alignment of bones, identifying some fractures and degenerative changes.

MRI

We carefully examine the disc, nerves, spinal canal, and soft tissues.

More precise examinations are not always required first. It is important to select an examination that matches the issue you wish to address in your current consultation.

• If there is severe nerve compression and progressive muscle weakness, we prioritize consultation.
• If infection, tumor, or fracture is suspected, this consultation should be done first.
• Even if disc herniation or stenosis is observed, we also examine current nerve function and movement.
• We do not treat only degenerative changes seen on imaging.
• If there are no warning signs and musculoskeletal function management is needed, the suitability of Chuna manual therapy can be assessed.
• We do not claim that Chuna manual therapy can restore the disc to its original position as shown on an MRI.

It varies depending on the type of treatment and the patient's symptoms.

Some drug treatments can be performed based on the medical history and physical examination. When planning an injection around a nerve or surgery, MRI may be needed depending on symptoms and examination results.

What matters is not the MRI scan itself, but whether its results actually change the choice of treatment.