This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Non-Invasive Characterization in Cardiac Sarcoidosis (NCT02017522), a na na study. The primary outcome is Ratio of 11C-PBR28 in the Myocardium.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02017522 |
| Phase | NA |
| Condition | Cardiac Sarcoidosis |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 3 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Michigan |
| Results posted | Yes |
2. Clinical Question
Population
People with cardiac sarcoidosis were the intended study population. The registry record lists an enrollment of 3. It does not give further eligibility details or report the characteristics of participants who enrolled.
Intervention
The study used 11C-PBR PET, listed as a device intervention. The registry summary describes use of a radiotracer to examine inflammation. The arm description also mentions blood testing related to a genetic variation and inflammatory cells, but does not fully describe what happened after the text about participants returning.
Comparator
There was no separate randomized control group. The registry lists a single-group model and no allocation. The primary outcome instead compares PET activity in myocardial regions classified as abnormal with activity in regions classified as normal within the imaging assessment.
Primary question
The primary question was whether 11C-PBR28 PET activity differed between myocardial regions with inflammation indicated by FDG PET and/or edema indicated by increased T2 signal on cardiac MRI, and myocardial segments that appeared normal on FDG PET and cardiac MRI. The outcome was defined as the intensity in abnormal regions expressed as a percentage of intensity in normal segments. The registry record reports insufficient myocardial tissue contrast to define abnormal and normal regions, and gives no numerical primary outcome estimate.
3. Trial Design
This was a single-group study listed under the title “Non-Invasive Characterization in Cardiac Sarcoidosis.” The condition was cardiac sarcoidosis, and the intervention was 11C-PBR PET. The registry classifies the intervention as a device and the study model as single group. Allocation is listed as NA, and masking is listed as NONE. There is no randomized between-group treatment comparison in the record.
The listed enrollment was 3. The study start date was 2014-04-04, and the primary completion date was 2015-07-07. Its status is TERMINATED. The reason for termination is not reported in the registry record. The phase is listed as NA, which does not specify a phase category.
The imaging outcome was framed as a comparison between regions of myocardium, rather than a comparison between separately assigned study arms. The intended abnormal regions were identified using FDG PET evidence of inflammation and/or increased T2 signal on cardiac MRI as an indication of edema. Regions appearing normal on FDG PET and cardiac MRI formed the reference for the uptake ratio. This is a within-study imaging contrast as described by the outcome definition; it should not be interpreted as a randomized comparison of 11C-PBR PET with another assigned intervention.
The registry lists 2 outcome measures and no statistical analyses. It does not report a protocol-level statistical plan, a sample-size justification, an interim analysis plan, or a reason for stopping. The record’s incomplete arm description does not establish a full schedule of study procedures or participant follow-up.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: Five potential participants signed consents, but only three passed screening.
Overall Study
| Stage | 11C-PBR PET |
|---|---|
| STARTED | 3 |
| Scan | 2 |
| COMPLETED | 2 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | 11C-PBR PET |
|---|---|
| Withdrawal by Subject | 1 |
Analysis population for the primary outcome, as defined in the registry: Insufficient myocardial tissue contrast to define abnormal and normal regions.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | 11C-PBR PET |
|---|---|---|
| Participants analysed | 3 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 2 |
| Age, Categorical: >=65 years | Participants | 1 |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 2 |
| Region of Enrollment: United States | Participants | 3 |
6. Primary Endpoint
The registry lists the primary outcome as Ratio of 11C-PBR28 in the Myocardium, measured over 1 hour scan.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was the ratio of 11C-PBR28 PET activity in the myocardium. Its stated purpose was to compare uptake in myocardial regions judged abnormal with uptake in segments that appeared normal. Abnormality was defined by inflammation indicated by FDG PET and/or edema indicated by increased T2 signal with cardiac MRI. The result was intended to express uptake in abnormal regions as a percentage of uptake in normal segments.
This type of endpoint can characterize whether the imaging signal differs across tissue regions within a study participant. A reference region matters because the endpoint is relative: the measured intensity in the target regions is interpreted in relation to the intensity in the segments designated normal. The endpoint is therefore not a measure of a treatment effect between randomized groups, nor does it directly describe a clinical outcome.
The stated timeframe was a 1 hour scan. The registry record reports insufficient myocardial tissue contrast to define abnormal and normal regions. It does not report a numerical ratio, a group summary, or an estimate of variability. Without a reported endpoint estimate, the magnitude and precision of the intended regional contrast cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes an imaging question, not a randomized test of a treatment. The primary outcome was intended to quantify relative 11C-PBR28 uptake in myocardial regions classified as abnormal compared with segments classified as normal. That definition identifies the scientific target, but the record does not provide a numerical outcome with which to assess the observed contrast.
The record lists insufficient myocardial tissue contrast to define abnormal and normal regions. This is important to interpretation because the endpoint depends on being able to distinguish those regions. The registry does not give further detail about the reason for insufficient contrast, whether the issue applied to all participants, or whether any individual-level uptake measures were obtained. Those details are not reported in the registry record, so the outcome status should not be generalized beyond what the record states.
No statistical analyses are listed. There is no reported estimate of the primary ratio, no measure of its uncertainty, and no reported hypothesis test or p-value. The registry therefore does not establish the direction or size of a regional uptake contrast, or how precisely such a contrast may have been estimated. It also does not report a result for the secondary outcome, the ratio of 11C-PBR28 PET activity in cardiac regions with fibrosis.
The enrollment of 3 indicates the listed scale of the study, but enrollment alone does not show how many participants contributed usable data to a particular endpoint. Nor can it substitute for an analysis population or a reported outcome estimate. The adverse-event record has its own risk-set counts and should not be used as a substitute for the enrollment figure or as evidence that all enrolled participants completed imaging.
The study is listed as terminated, but the reason is not reported in the registry record. Termination by itself does not explain whether the study ended because of feasibility, recruitment, scientific findings, administrative decisions, or another circumstance. No such explanation should be inferred from status alone.
In general, an estimate accompanied by an uncertainty interval helps readers distinguish the estimated signal from the range of values compatible with the data under the analysis assumptions. Neither an estimate nor an interval is reported for this primary outcome. The registry record consequently supports a description of the intended endpoint and its reported tissue-contrast limitation, but not a quantitative conclusion about the regional PET signal.
9. Statistical Methods Explained
The study design and the endpoint definition determine what kinds of statistical interpretation are possible. This record lists a single-group model, no allocation, and no masking. It does not describe assignment to competing interventions. The primary outcome instead compares PET activity across types of myocardial regions. That distinction matters: a regional imaging contrast is not a between-arm treatment effect, and it does not have the same interpretation as a randomized clinical trial comparison.
What does the regional ratio represent?
In general, a ratio expresses one measured quantity relative to another. Here, the intended numerator was PET activity in myocardial regions with inflammation indicated by FDG PET and/or edema indicated by increased T2 signal on cardiac MRI. The reference was activity in myocardial segments that appeared normal on FDG PET and cardiac MRI. The endpoint description states that the result would express abnormal-region intensity as a percentage of normal-segment intensity. It is therefore a relative measure, and its interpretation depends on how the abnormal and normal regions are identified and whether both can be measured with adequate contrast.
A ratio can be useful when the research question concerns relative signal rather than an absolute measurement. But the reference region is not incidental: if it cannot be reliably distinguished, the intended comparison is difficult to define. The registry record specifically reports insufficient myocardial tissue contrast to define abnormal and normal regions. It does not give a ratio or explain in more detail how that limitation affected the planned endpoint.
Why does the absence of an estimate matter?
Statistical interpretation ordinarily begins with an estimate of the outcome and a description of its uncertainty. The estimate indicates the observed magnitude of a quantity; an uncertainty interval describes how imprecisely it is estimated under the stated method. A hypothesis test, when planned and reported, addresses a different question under specified assumptions. These summaries should be read together when available. For this study, the registry lists no analyses and does not report a primary outcome estimate, uncertainty interval, or p-value. The intended endpoint can be described, but its numerical size and precision cannot be evaluated from this record.
In general, a small enrolled sample can limit the precision of an estimate, particularly when the outcome varies across participants. Enrollment is not itself an estimate of precision, and it does not show how many observations were available for a particular analysis. The registry lists an enrollment of 3, but does not report the number of participants with evaluable primary endpoint data or an analysis population. No estimate of observed variability is reported either. Consequently, there is no basis in the record for quantifying precision or reconstructing an analysis.
What is the role of a comparison group?
A randomized comparison can support an estimate of differences between assigned groups, subject to the study’s design and analysis assumptions. This record does not list a randomized comparator group. The primary endpoint compares tissue regions, not outcomes in participants assigned to distinct study arms. A regional contrast may be informative for the imaging question, but it does not establish a causal treatment effect or compare the PET procedure with an alternative intervention.
In general, paired or within-participant measurements can account for some features shared by regions from the same participant. They also require appropriate handling of dependence: measurements from regions in one person are not necessarily statistically independent. The registry record does not report the statistical method for handling regional measurements, the number of regions analyzed, or whether the analysis was performed at the participant or region level. No particular method should therefore be attributed to the investigators.
How should planning calculations be understood?
In general, sample-size calculations are planning tools based on assumptions about the outcome, the effect of interest, variability, allocation, and analysis. A planning illustration is not an observed result and does not show the probability that a completed study has detected an effect. The registry record does not report the study’s own sample-size justification or the assumptions behind its design. It also does not report a numerical observed effect for the primary outcome. Thus, no conclusion about observed power or the adequacy of the original design follows from the record.
Statistical significance, if reported, would not by itself describe the magnitude or practical meaning of an imaging contrast. Conversely, a non-significant result would not prove that no contrast exists. Those general cautions are especially relevant when estimates and uncertainty are absent. Here, there is no reported test result to interpret, and the tissue contrast limitation is a direct concern for defining the primary endpoint.
The registry also lists a secondary outcome concerning the ratio of 11C-PBR28 PET activity in cardiac regions with fibrosis. It does not provide a result or an analysis for that outcome. No relationship between the primary and secondary outcomes, no analysis hierarchy, and no adjustment strategy can be identified from the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 2 outcome measures: the primary ratio of 11C-PBR28 in the myocardium and a secondary ratio of 11C-PBR28 PET activity in cardiac regions with fibrosis. It lists no statistical analyses. A prespecified testing hierarchy, multiplicity adjustment, or strategy for interpreting multiple outcomes is not reported in the registry record. Without those details or any posted test results, the record does not support an assessment of how multiple outcome questions were handled statistically.
The registry does not report missing-data counts, reasons for missingness, or methods for handling missing observations. It also does not state how participants with no usable imaging contrast would be handled in an analysis. The primary outcome entry reports insufficient myocardial tissue contrast to define abnormal and normal regions, but the record does not clarify which participants or observations this applied to. It would be inappropriate to assume that missingness was absent, or to infer a particular imputation or exclusion method.
An analysis population is not described. The enrolled count is 3, but the record does not say how many participants were included in any endpoint analysis or whether any participants were excluded. No intention-to-treat, per-protocol, or other population definition is reported in the registry record. These gaps prevent reconstruction of the population underlying a statistical estimate, and there is no reported estimate to reconstruct.
In general, multiplicity methods address the increased chance of misleading findings when several statistical questions are tested. Missing-data methods address how incomplete observations affect estimates. These are distinct issues, and neither can be resolved from the outcome labels alone. The registry’s lack of an analysis plan or reported analyses leaves both issues unspecified.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| 11C-PBR PET | 0 | 2 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| 11C-PBR PET | 0 of 2 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| 11C-PBR PET | 0 of 2 |
The registry’s adverse-event entry for the 11C-PBR PET group lists 2 participants at risk for serious adverse events and 0 participants affected. It also lists 2 participants at risk for other adverse events and 0 affected. Deaths are listed as 0. These are the counts in the adverse-event record; they are not a complete description of all safety monitoring or all clinical events.
The adverse-event risk set is listed as 2, while total enrollment is 3. The registry does not explain the difference or report why a participant is not represented in the listed risk set. The period during which events were collected, the event ascertainment procedures, and the details of any non-serious events are not reported in the registry record. No serious adverse-event terms are listed.
Zero reported events in the listed risk set should be read as a count in this record, not as proof that an intervention has no risks. The small listed risk set and the absence of further safety details limit what can be concluded. These figures do not establish a comparative safety profile because there was no separate control group in the single-group design.
12. What the Result Does, and Does Not, Mean
The record describes a study intended to characterize myocardial 11C-PBR28 PET uptake in cardiac sarcoidosis. Its primary endpoint was a relative comparison of activity in regions classified as abnormal with activity in segments classified as normal. The record reports insufficient myocardial tissue contrast to define those regions, and no numerical primary outcome estimate or statistical analysis is listed.
Accordingly, the posted results do not show the magnitude, direction, or precision of a regional uptake difference. They also do not establish whether the imaging measure can distinguish the specified myocardial regions in a broader population. The registry record does not report a numerical result for the secondary outcome concerning regions with fibrosis.
The single-group design is not a randomized comparison of treatments. The endpoint compares regions within the imaging assessment, so its intended interpretation is different from an estimate of benefit or harm between assigned interventions. The record does not support claims about treatment effectiveness, clinical outcomes, or comparative performance against another imaging approach.
The study status is TERMINATED, but the reason for termination is not reported in the registry record. The status alone cannot identify whether the decision related to feasibility, recruitment, imaging, or other considerations. Likewise, enrollment of 3 does not reveal how many participants contributed usable endpoint data.
In general, a complete interpretation of an imaging outcome would benefit from a clearly defined analysis population, an estimate, an uncertainty measure, and an account of how the regions were classified. Those details are not reported in the registry record. The defensible interpretation is therefore limited to the study’s stated question and the recorded limitation in defining abnormal and normal myocardial regions.
13. Why This Trial Matters Statistically
This study raises a basic statistical issue in imaging research: a quantitative endpoint can only be interpreted if the target and reference regions can be distinguished and measured. The primary outcome was defined as a relative comparison of 11C-PBR28 PET activity in abnormal and normal myocardial segments. The record’s statement that tissue contrast was insufficient to define those regions identifies a challenge at the level of endpoint construction, before the size or precision of a statistical estimate can be assessed.
The design also illustrates why within-participant imaging contrasts should not be confused with randomized treatment comparisons. The study is listed as single group, with allocation NA, and no separate control arm. Its stated question concerns regional uptake patterns, not a causal difference between assigned interventions. Keeping that distinction clear prevents an imaging characterization question from being read as evidence about treatment effects.
Another statistical lesson is the importance of linking enrollment to endpoint evaluability. The registry lists enrollment of 3, but provides no analysis population or numerical outcome estimate. The adverse-event group separately lists 2 at risk. These counts answer different questions and do not identify how many participants contributed to the primary imaging outcome. Without that information, neither analysis completeness nor endpoint precision can be assessed.
Finally, a registry entry can define a scientific question without supplying the analysis needed to answer it quantitatively. Here, the outcome definition and timeframe are recorded, but no statistical analyses are listed. That distinction matters when interpreting small or terminated studies: design intent, endpoint feasibility, and an observed statistical result are separate elements, and the available record does not establish all of them.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The main limitation specific to this study is that the registry record reports insufficient myocardial tissue contrast to define abnormal and normal regions, although that distinction is central to the primary endpoint. The record does not clarify how this affected individual participants, whether any scans were evaluable, or whether another endpoint assessment was possible. No numerical primary outcome is reported.
The listed enrollment is 3, and no analysis population is described. The number of participants contributing data to the primary or secondary outcomes is not reported. The adverse-event entry lists 2 at risk, but the registry does not explain how that risk set relates to enrollment. These details make it difficult to assess completeness of endpoint data or the precision of any potential estimate.
The design is single group, with allocation NA and masking NONE. There is no randomized comparator for interpreting regional uptake as a treatment effect. The registry also lists no statistical analyses, and does not report the analysis methods, handling of repeated or regional measurements, missing-data approach, or adjustment for multiple outcomes.
The study is marked TERMINATED, but the reason is not reported in the registry record. The record does not describe the study’s sample-size justification or interim analysis plan. The timeframe is stated as a 1 hour scan, but additional follow-up or data-collection timing is not reported for the primary outcome. These limitations restrict interpretation to the stated imaging objective, the reported tissue-contrast issue, and the listed descriptive record details.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Non-Invasive Characterization in Cardiac Sarcoidosis — NCT02017522.
- Registry record last updated 2018-08-01; status last verified 2018-07.
- Results first posted 2018-08-01.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry record identifies NCT02017522 as “Non-Invasive Characterization in Cardiac Sarcoidosis,” sponsored by the University of Michigan. The condition is cardiac sarcoidosis, and the intervention is 11C-PBR PET, listed as a device. The study model is single group; allocation is NA and masking is NONE. Enrollment is listed as 3, with a start date of 2014-04-04 and primary completion date of 2015-07-07. Status is TERMINATED, and the reason is not reported in the registry record.
The primary endpoint was a ratio of 11C-PBR28 PET activity in myocardial regions identified as abnormal relative to segments appearing normal. The registry reports insufficient myocardial tissue contrast to define those regions. It lists 2 outcome measures and no statistical analyses, and reports no numerical primary outcome estimate, uncertainty interval, or p-value. The adverse-event entry lists 2 participants at risk, 0 serious events, 0 other events, and 0 deaths.