Use of PET/MR Imaging in Chronic Pain

The diagnosis and management of chronic and neuropathic pain syndromes remains a major
clinical challenge, and this failure is partly attributed to our inability to identify the
hypersensitive and inflammatory changes in the pain-sensing part of our nervous system that
is thought to contribute to these syndromes. The lack of a specific, objective diagnostic
test for chronic and neuropathic pain syndromes can result in a delay of diagnosis and
suboptimal management decisions. This delay in diagnosis is quite unfortunate since the early
diagnosis and treatment of a disease is attributed to the highest probability of remission in
certain chronic pain syndromes. Additionally, identifying the correct source of pain is of
paramount importance since the clinical course and therapeutic interventions are different
depending on cause.

Evidence in the literature points strongly toward an active inflammatory component in chronic
pain. For example, soft tissue and bony inflammation is known to be an important
pathophysiological mechanism for the symptoms of certain neuropathic pain syndromes.
Similarly, individuals suffering from chronic sciatica or radiculopathy may suffer from a
combination of inflammation and compression of lumbar or cervical spinal nerves. It is also
established that inflammatory lesions have increased metabolism and energy requirements and,
therefore, are more glucose-avid than normal tissues, showing increased uptake of
radiolabeled glucose analogs, such as [18F]fluorodeoxyglucose ([18F]FDG). Correspondingly,
[18F]FDG positron emission tomography-magnetic resonance imaging (PET/MRI) represent leading
FDA-approved clinical imaging modalities to longitudinally study metabolic changes in the
nervous system and non-neural tissues (e.g., muscle, blood vessels, joints, bone, scar
tissue, etc.) in patients with chronic pain conditions. One of the goals of the study is to
determine whether [18F]FDG PET/MRI can identify sources of inflammation with greater
sensitivity, accuracy and objectivity than current diagnostic methods.

Inclusion Criteria:

- Age 18 years or older.

- Clinically diagnosed chronic pain lasting greater than 2 months. Some example
diagnoses include (but not limited to): Low back pain, sciatica, complex regional pain
syndrome, post-traumatic pain, peripheral nerve injury, fibromyalgia, neuropathy,
osteoarthritis, cancer pain, persistent post-operative pain, traumatic brain injury,
pain from chronic cerebrospinal fluid leak, headache/migraine, chronic pruritus,
rheumatologic disease, neuropathy (diabetic-induced, Charcot-Marie-Tooth, CIDP), etc.

- Provides informed consent.

- On a typical day, the subject must have a minimum pain level of 4 on a 0-10
Comparative Pain Scale.

Exclusion Criteria:

- Presence of MRI-incompatible materials/devices.

- Diabetes.

- Severe claustrophobia.

- Diagnosed psychiatric disorder that, in the opinion of the investigator, would impede
participation in the study.

- Pregnant or nursing.

- Severe comorbid conditions.

- Unable to read or complete questionnaires in English.

- Any other condition, which in the opinion of the investigator would impede compliance
or hinder completion of the study.