PainNCT06171659
FDG PET/MR Imaging of Peripheral Pain Generators
An observational study of Pain and Nociceptive Pain, run by University of Wisconsin, Madison at 1 site in United States.
Trial summary
The purpose of this research is to determine if a PET/MRI scan using FDG can accurately identify the source of chronic pain. Identifying the source of pain may help doctors treat chronic pain more effectively. Approximately 128 participants will be enrolled and can expect to be on study for up to 12 months. Read more about this study
- Who is it for?
- Ages 18 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Pain, Nociceptive Pain
- What is being tested?
- FDG radiotracer, PET/MRI and PET/CT imaging
- Type of treatment
- Injection or infusion, Medical device
- How many people
- 128 participants
- Where
- 1 siteUnited States
- Study dates
- 19 Nov 2024to Jun 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Participants with persistent post-surgical pain and asymptomatic individuals who have undergone joint arthroplasty (hip or knee) or joint arthroscopy (hip or knee).
Who may be able to join
- 18-85 years old
- Presents with persistent pain with pain score of ≥4 on Numerical Rating Scale [0:10] for at least 6 months following joint arthroplasty or arthroscopy.
- Able and willing to provide informed consent
- Willing and able to undergo PET/MRI (arthroplasty and arthroscopy participants) and PET/CT (arthroplasty participants only)
- 18-85 years old
- Asymptomatic (pain score of ≤2 on the NRS) for at least 6 months following joint arthroplasty or arthroscopy.
- Able and willing to provide informed consent
- Willing and able to undergo PET/MRI
Who cannot join
- Inability to understand and communicate with the investigators to complete the study-related questionnaires.
- Any co-morbidity which results in severe systemic disease limiting function as defined by the American Society of Anesthesiology (ASA) physical status classification > 3, such as the presence of current or past (6 months) pulmonary, hepatic, renal disease, arthritis, hematopoietic, and neurological diseases not related to chronic pain.
- Pregnant or breastfeeding. (Individuals with childbearing potential will be asked to verbally confirm they are not pregnant. If they cannot confirm, they will have a urine pregnancy test either at the imaging study visit or within 7 days prior to the imaging study visit.)
- Subject with contraindication(s) to or inability to undergo PET/MRI
- Current diagnosis of malignancy of any kind. Participants in remission for at least two years and not undergoing any treatment may be considered per investigator discretion
- Current enrollment in a scientific interventional or treatment study.
- Subject unable or unwilling to provide informed consent
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
UW School of Medicine and Public Health
Madison, Wisconsin, 53792
About this study
Official title: FDG PET/MR Imaging of Peripheral Pain Generators in Persistent Post-Surgical Pain (PPSP)
The purpose of this research is to determine if a PET/MRI scan using FDG can accurately identify the source of chronic pain. Identifying the source of pain may help doctors treat chronic pain more effectively. Approximately 128 participants will be enrolled and can expect to be on study for up to 12 months.
Read the detailed description
The investigators aim to precisely localize sites of increased inflammation and potentially pain generation and improve understanding of nociception and inflammation using a unique, hybrid PET/MRI approach in conjunction with intravenously, administered fluorodeoxyglucose (FDG), which has been shown with PET imaging to be an sensitive surrogate marker of inflammation.
The Primary Objective of this pilot prospective, observational research is to determine whether this approach, which combines PET/MRI and an FDA-approved radiotracer, 18F-Fluorodeoxyglucose (FDG), can accurately localize the sites of painful inflammation in individuals with persistent pain.
- Determine if increased FDG uptake on PET as measured by standard uptake value (SUV) or target-to-background (TTB) measurements is increased in area of pain symptoms when compared to same corresponding areas in healthy, asymptomatic volunteers.
- Determine whether amount of FDG uptake as measured on PET is able to localize to abnormalities when compared to MR imaging (T2 signal intensity, morphologic aberrations)
Secondary Objectives:
- Verify that the standard administered adult dose of FDG (0.14 mCi/kg/patient) used currently in the clinics can also be used to detect peripheral pain generators.
- Verify that FDG uptake in asymptomatic, healthy controls will be significantly less than their chronic pain cohorts at the same anatomic location.
- Determine whether longitudinal FDG PET/MR imaging findings in individual patients directly correlate with symptoms as they evolve over time in joint arthroplasty subjects with PPSP.
- Determine if FDG PET/MR imaging findings spatially differ between different pain types.
- Conditions
- Pain, Nociceptive Pain
- Being tested
- FDG radiotracer, PET/MRI, PET/CT imaging
- Medical subject headings
- Pain, Nociceptive Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
FDG radiotracerDrug
Also called fluorodeoxyglucose, 18F-Fluorodeoxyglucose
Fludeoxyglucose F 18 Injection is a positron emitting radiopharmaceutical containing no-carrier added radioactive 2-deoxy-2-[18F]fluoro-D-g1ucose, which is used for diagnostic purposes in conjunction with Positron Emission Tomography (PET). It is administered by intravenous injection. Dosage planned 0.14 mCi/kg/patient.
PET/MRIDevice
positron emission tomography and magnetic resonance imaging
PET/CT imagingDevice
positron emission tomography and computed tomography imaging
| Study group | Role | What they receive |
|---|---|---|
| Open Surgical Procedure (Arthroplasty) | PPSP subjects who have undergone hip (or knee) joint arthroplasty (i.e., open surgical procedure for joint replacement).
* 6 month post-op scans
* 12 month post-op scans
* 18 month post-op scans Receives: Drug: FDG radiotracer; Device: PET/MRI; Device: PET/CT imaging | |
| Less Invasive Procedure (Arthroscopy) | PPSP subjects who have undergone hip (or knee) arthroscopy (i.e., less invasive joint surgical procedure involving scopes and lower profile surgical tools)
- 6 month post-op scans Receives: Drug: FDG radiotracer; Device: PET/MRI | |
| Asymptomatic: Had Total Joint Replacement (Arthroplasty) | Asymptomatic subjects who have undergone total hip or total knee arthroplasty.
- single scan during one study visit (up to 3.5 hours) Receives: Drug: FDG radiotracer; Device: PET/MRI | |
| Asymptomatic: Less Invasive Procedure (Arthroscopy) | Asymptomatic subjects who have undergone hip or knee arthroscopy.
- single scan during one study visit (up to 3.5 hours) Receives: Drug: FDG radiotracer; Device: PET/MRI |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in SUVmax (chronic pain)
Measured: baseline (6 months post-op), 12 months post-op, 18 months post-op
SUVmax (chronic pain vs healthy)
Measured: baseline
Location of Pain Compared to Target-to-Background (TTB) or SUVmax
Measured: baseline
Secondary outcomes (5)
Number of Participants Where Standard FDG dose was sufficient to detect region of pain (symptomatic groups)
The standard administered adult dose of FDG currently used in clinics is 0.14 mCi/kg/patient.
Measured: baseline
Variation of the maximum ratio of SUV (SUVRmax) in asymptomatic controls vs symptomatic
Measured: baseline
Variation of the maximum ratio of SUV (SUVRmax) in symptomatic participants
Measured: baseline (6 months post-op), 12 months post-op, 18 months post-op
Radiology Review Scores
Radiologists will evaluate MRI and CT images from each exam, and assign 1 point to any abnormality detected in the following compartments: prosthesis itself, bone, joint space, joint capsule, muscle, subcutaneous fat, and skin, for a total of 7 possible points. Differences in scoring from MRI vs CT images will be further investigated with a t-test.
Measured: up to 18 months post-op
Change in Pain Scores (chronic pain)
Pain will be evaluated on a scale of 0 (no pain) to 10 (worse possible pain).
Measured: baseline (6 months post-op), 12 months post-op, 18 months post-op
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Dec 2023
- Study start19 Nov 2024
- Primary completionJun 2028 (estimated)
- Study completionJun 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PainStudies of the same condition, open and under way.
- More trials run by University of Wisconsin, MadisonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 128 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Wisconsin, Madison
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), Arthroscopy Association of North America
- Responsible party
- Sponsor
- Investigators
- Sandip Biswal, MD, Principal investigator, University of Wisconsin, Madison
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06171659
- Sponsor's protocol ID
- 2023-0884
- Other IDs
- R01AR077706, SMPH/RADIOLOGY/RADIOLOGY, Protocol Version 5/28/2026
- Status last verified
- Jul 2026
- First submitted
- 4 Dec 2023
- Last updated
- 17 Jul 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- FDG PET/MR Imaging of Peripheral Pain Generators in Persistent Post-Surgical Pain (PPSP)
- ClinicalTrials.gov ID
- NCT06171659
- Acronym / sponsor ID
- 2023-0884
- Conditions
- Pain, Nociceptive Pain
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 128 participants (estimated)
- Lead sponsor
- University of Wisconsin, MadisonUniversity, hospital or other
- Collaborators
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), Arthroscopy Association of North America
- Study start
- 19 Nov 2024 (actual)
- Primary completion
- Jun 2028 (estimated)
- Study completion
- Jun 2028 (estimated)
- First posted
- 15 Dec 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this research is to determine if a PET/MRI scan using FDG can accurately identify the source of chronic pain. Identifying the source of pain may help doctors treat chronic pain more effectively. Approximately 128 participants will be enrolled and can expect to be on study for up to 12 months.
Detailed description
The investigators aim to precisely localize sites of increased inflammation and potentially pain generation and improve understanding of nociception and inflammation using a unique, hybrid PET/MRI approach in conjunction with intravenously, administered fluorodeoxyglucose (FDG), which has been shown with PET imaging to be an sensitive surrogate marker of inflammation.
The Primary Objective of this pilot prospective, observational research is to determine whether this approach, which combines PET/MRI and an FDA-approved radiotracer, 18F-Fluorodeoxyglucose (FDG), can accurately localize the sites of painful inflammation in individuals with persistent pain.
- Determine if increased FDG uptake on PET as measured by standard uptake value (SUV) or target-to-background (TTB) measurements is increased in area of pain symptoms when compared to same corresponding areas in healthy, asymptomatic volunteers.
- Determine whether amount of FDG uptake as measured on PET is able to localize to abnormalities when compared to MR imaging (T2 signal intensity, morphologic aberrations)
Secondary Objectives:
- Verify that the standard administered adult dose of FDG (0.14 mCi/kg/patient) used currently in the clinics can also be used to detect peripheral pain generators.
- Verify that FDG uptake in asymptomatic, healthy controls will be significantly less than their chronic pain cohorts at the same anatomic location.
- Determine whether longitudinal FDG PET/MR imaging findings in individual patients directly correlate with symptoms as they evolve over time in joint arthroplasty subjects with PPSP.
- Determine if FDG PET/MR imaging findings spatially differ between different pain types.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Open Surgical Procedure (Arthroplasty) | – | Drug: FDG radiotracer, Device: PET/MRI, Device: PET/CT imagingPPSP subjects who have undergone hip (or knee) joint arthroplasty (i.e., open surgical procedure for joint replacement). * 6 month post-op scans * 12 month post-op scans * 18 month post-op scans |
| Less Invasive Procedure (Arthroscopy) | – | Drug: FDG radiotracer, Device: PET/MRIPPSP subjects who have undergone hip (or knee) arthroscopy (i.e., less invasive joint surgical procedure involving scopes and lower profile surgical tools) - 6 month post-op scans |
| Asymptomatic: Had Total Joint Replacement (Arthroplasty) | – | Drug: FDG radiotracer, Device: PET/MRIAsymptomatic subjects who have undergone total hip or total knee arthroplasty. - single scan during one study visit (up to 3.5 hours) |
| Asymptomatic: Less Invasive Procedure (Arthroscopy) | – | Drug: FDG radiotracer, Device: PET/MRIAsymptomatic subjects who have undergone hip or knee arthroscopy. - single scan during one study visit (up to 3.5 hours) |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Participants with persistent post-surgical pain and asymptomatic individuals who have undergone joint arthroplasty (hip or knee) or joint arthroscopy (hip or knee).
Key inclusion criteria (8 listed)
- 18-85 years old
- Presents with persistent pain with pain score of ≥4 on Numerical Rating Scale [0:10] for at least 6 months following joint arthroplasty or arthroscopy.
- Able and willing to provide informed consent
- Willing and able to undergo PET/MRI (arthroplasty and arthroscopy participants) and PET/CT (arthroplasty participants only)
- 18-85 years old
Key exclusion criteria (7 listed)
- Inability to understand and communicate with the investigators to complete the study-related questionnaires.
- Any co-morbidity which results in severe systemic disease limiting function as defined by the American Society of Anesthesiology (ASA) physical status classification > 3, such as the presence of current or past (6 months) pulmonary, hepatic, renal disease, arthritis, hematopoietic, and neurological diseases not related to chronic pain.
- Pregnant or breastfeeding. (Individuals with childbearing potential will be asked to verbally confirm they are not pregnant. If they cannot confirm, they will have a urine pregnancy test either at the imaging study visit or within 7 days prior to the imaging study visit.)
- Subject with contraindication(s) to or inability to undergo PET/MRI
- Current diagnosis of malignancy of any kind. Participants in remission for at least two years and not undergoing any treatment may be considered per investigator discretion
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| FDG radiotracerAlso: fluorodeoxyglucose, 18F-FluorodeoxyglucoseFludeoxyglucose F 18 Injection is a positron emitting radiopharmaceutical containing no-carrier added radioactive 2-deoxy-2-[18F]fluoro-D-g1ucose, which is used for diagnostic purposes in conjunction with Positron Emission Tomography (PET). It is administered by intravenous injection. Dosage planned 0.14 mCi/kg/patient. | Drug | Asymptomatic: Had Total Joint Replacement (Arthroplasty), Asymptomatic: Less Invasive Procedure (Arthroscopy), Less Invasive Procedure (Arthroscopy), Open Surgical Procedure (Arthroplasty) |
| PET/MRIpositron emission tomography and magnetic resonance imaging | Device | Asymptomatic: Had Total Joint Replacement (Arthroplasty), Asymptomatic: Less Invasive Procedure (Arthroscopy), Less Invasive Procedure (Arthroscopy), Open Surgical Procedure (Arthroplasty) |
| PET/CT imagingpositron emission tomography and computed tomography imaging | Device | Open Surgical Procedure (Arthroplasty) |
Primary outcome
Change in SUVmax (chronic pain)
Time frame: baseline (6 months post-op), 12 months post-op, 18 months post-op
SUVmax (chronic pain vs healthy)
Time frame: baseline
Location of Pain Compared to Target-to-Background (TTB) or SUVmax
Time frame: baseline
5 secondary outcomes
Number of Participants Where Standard FDG dose was sufficient to detect region of pain (symptomatic groups)
Time frame: baseline
Variation of the maximum ratio of SUV (SUVRmax) in asymptomatic controls vs symptomatic
Time frame: baseline
Variation of the maximum ratio of SUV (SUVRmax) in symptomatic participants
Time frame: baseline (6 months post-op), 12 months post-op, 18 months post-op
Radiology Review Scores
Time frame: up to 18 months post-op
Change in Pain Scores (chronic pain)
Time frame: baseline (6 months post-op), 12 months post-op, 18 months post-op
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Jul 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Sandip Biswal, MD principal investigator
University of Wisconsin, Madison
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Pain and Nociceptive Pain, run by University of Wisconsin, Madison at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 17 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Radiology Studies (608-282-8349, Radstudy@uwhealth.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in SUVmax (chronic pain) (time frame: baseline (6 months post-op), 12 months post-op, 18 months post-op). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Jul 2026.