Phenotyping Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) by Intravesical Contrast Enhanced - Magnetic Resonance Imaging (ICE-MRI) Bladder Permeability Assay: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Phenotyping Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) by Intravesical Contrast Enhanced - Magnetic Resonance Imaging (ICE-MRI) Bladder Permeability Assay (NCT05811377), a registered phase not stated study. The primary outcome is Bladder Permeability.

2. Clinical Question

This question concerns whether an imaging measure can distinguish participant phenotypes, rather than whether one treatment is more effective than another. The study summary describes the MRI as assessing whether the bladder is leaky and notes preliminary data suggesting greater Gadobutrol in the bladder wall lining among IC patients with Hunner lesions. That context explains the rationale, but it is not a reported result for this study. The posted record gives no numerical primary-outcome results with which to evaluate the proposed distinction. Consequently, neither the size nor the precision of any observed difference can be described from the registry record.

3. Trial Design

This completed study, NCT05811377, is titled “Phenotyping Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) by Intravesical Contrast Enhanced - Magnetic Resonance Imaging (ICE-MRI) Bladder Permeability Assay.” The registry lists an enrollment of 7 and identifies interstitial cystitis as the condition. The recorded study start was 2023-03-29 and the primary completion date was 2025-02-07. The sponsor is Christopher J Chermansky, MD.

The study summary describes a single MRI test involving contrast introduced into the bladder through a sterile catheter. Ferumoxytol and Gadobutrol are listed as diagnostic-test interventions. The two groups are defined by cystoscopy performed before ICE-MRI: Non-Hunner IC includes participants without a Hunner lesion, and Hunner IC includes participants with a Hunner lesion. The registry does not describe random assignment, and its record explicitly cautions that the arms are not a like-for-like control comparison. They represent groups classified by lesion status, not groups assigned to different therapies.

The primary outcome is a continuous measure of bladder permeability, reported as a mean with standard deviation, at 12 min image post-contrast. The registry lists one outcome measure and one analysis. It does not report the analysis method, the number of participants included in the outcome analysis, or numerical outcome results. The distinction matters: enrollment describes the study overall, but it does not by itself establish how many participants contributed usable measurements to each group or to the analysis.

The record’s description is sufficient to identify the general imaging procedure and the phenotype-based comparison, but it does not give a full protocol or statistical analysis plan. Details such as recruitment criteria, measurement procedures beyond the brief outcome description, handling of unusable scans, and the planned method for comparing groups are not reported in the registry record.

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.

Overall Study

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.

6. Primary Endpoint

The registry lists the primary outcome as Bladder Permeability, measured over 12 min image post-contrast.

The primary endpoint is titled Bladder Permeability and is measured in artificial units. It is a continuous outcome summarized using a mean and standard deviation. The recorded assessment time is 12 min image post-contrast. According to the outcome description, permeability is represented by changes in absorption of instilled Gadobutrol, assessed through MRI signal intensity. The description associates brighter bladder-wall appearance with higher artificial-unit values and greater absorption, and darker appearance with lower values. It also says that elevated absorption was assessed with a darker appearance of the bladder center.

In general, a continuous imaging measure can retain more detail than a simple classification such as “leaky” or “not leaky”: it can describe the level of a measured signal across participants. Comparing group means may therefore help characterize whether the measure differs between the cystoscopy-defined phenotypes. The standard deviation describes variation among observations around the group mean; it does not by itself show how precisely the difference between groups has been estimated.

The endpoint is relevant to the study’s stated aim of phenotyping IC/BPS using an imaging assay. However, the registry record does not report the group means, standard deviations, a between-group estimate, or a confidence interval. It also does not provide sufficient information to resolve the wording that links greater absorption both to brighter bladder-wall appearance and to a darker bladder center. Without the numerical results and fuller measurement details, readers cannot determine the observed direction, magnitude, or precision of the primary endpoint comparison.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies bladder permeability as a continuous primary outcome, with the mean and standard deviation as the stated summary measures. It also lists one outcome measure and one analysis. These entries describe the broad outcome structure; they do not reveal which statistical test or model was used. The specific analysis method is not reported in the registry record.

What a mean describes

In general, a mean is the arithmetic average of observed measurements in a group. For an imaging outcome expressed in artificial units, a group mean would provide a compact description of the recorded signal levels. A comparison of means can summarize the average difference between groups, but it does not show whether individual measurements overlap substantially or whether a measure can classify individual participants. Those questions require additional information and analyses.

What a standard deviation describes

In general, a standard deviation describes how spread out individual observations are around their group mean. It is a measure of variability among observations, not a measure of uncertainty in the estimated mean and not the same as a confidence interval. Interpretation of a standard deviation depends on the data and sample size. With a small group, a few individual measurements can have considerable influence on the mean and on the apparent pattern of variation. The registry does not report the group standard deviations or the participant-level measurements.

How a group contrast would be interpreted

In general, a difference between group means expresses the observed contrast in the outcome’s original units. A confidence interval around that contrast would describe statistical uncertainty, conditional on the analysis and its assumptions. A narrow interval indicates greater precision than a wide interval, but neither the estimate nor its interval establishes causation. For this study, the outcome values and uncertainty estimates are not reported in the registry record, so no numerical contrast or precision assessment can be made.

The two groups are based on cystoscopy findings before MRI. The record does not state random allocation and specifically warns that the arms are not a like-for-like control comparison. In general, a comparison of groups defined by participant characteristics may reflect differences in those characteristics and in other factors, as well as any relationship with the measured outcome. The registry does not identify an adjusted analysis or report which potential confounders, if any, were considered. It would therefore be inappropriate to describe a hypothetical group contrast as a causal effect.

Why the measurement description matters

The endpoint description links Gadobutrol absorption to MRI signal intensity and artificial-unit values. In general, an imaging measure is interpretable only to the extent that the measurement process and direction of the scale are clear. Here, the written description associates brighter bladder-wall appearance with greater absorption and higher values, while also stating that elevated absorption was assessed with a darker appearance of the bladder center. Those statements may concern different visual features, but the record does not explain their relationship. This ambiguity limits a reader’s ability to translate a numerical change into a plain-language description of the image.

The assessment time is specified as 12 min image post-contrast. This anchors the endpoint to a particular point in the imaging procedure, but the registry does not report more detailed acquisition or processing procedures. For example, the timing entry alone does not establish how regions of interest were selected, how signal was converted to artificial units, or whether readings were independently reviewed. Such details are not reported in the registry record and should not be inferred.

Planning calculations are not observed findings

In general, sample-size planning asks how many participants would be needed to detect a specified effect under stated assumptions. The planning description associated with this study refers to a two-sided significance level of 0.05, equal allocation between arms, a normal approximation, and effects defined as fractions of an observed effect. It characterizes those calculations as planning illustrations, not as the trial’s original design justification. No resulting participant counts or observed effect value are reported in the registry record. Those planning assumptions cannot be used to infer an outcome, to reconstruct the original study rationale, or to claim observed power. Sample-size illustrations are hypothetical design aids, not evidence that a result is reliable or clinically meaningful.

Overall, the available method description identifies a continuous imaging endpoint and phenotype-based groups, but leaves key analytical details unspecified. The exact statistical test or model, the handling of missing observations, any adjustment for participant characteristics, and the confidence interval method are not reported in the registry record. Without these details and the numerical endpoint results, readers can explain the general statistical concepts but cannot reproduce or fully evaluate the study’s primary analysis.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Non-Hunner IC", "Hunner IC")
n   <- c(5, 2)
m   <- c(202.28, 144.25)
sp  <- c(11.958, 7.4)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Non-Hunner IC  5  202.280  11.958  187.432  217.128
CARM  Hunner IC  2  144.250  7.400  77.764  210.736

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure and one analysis. This is useful descriptive information, but it does not establish that only one statistical comparison or outcome was examined across the complete study. The registry record does not report a multiplicity strategy, such as whether multiple comparisons were planned or how any were handled. It is therefore not possible to determine from the record whether adjustment for multiple testing was relevant or used. No multiplicity correction should be assumed.

Missing-data handling is also not reported in the registry record. The total enrollment is 7, but the record does not state how many participants contributed a usable MRI measure, whether any scans were incomplete or excluded, or how missing observations were treated. It does not describe an imputation method or a sensitivity analysis. Enrollment should not be mistaken for the denominator in the primary outcome analysis.

The analysis population is not described. The record does not say whether the primary analysis included all enrolled participants, only those who completed the imaging procedure, or another defined subset. It also does not give group-specific outcome denominators. Consequently, the number of observations behind any group mean or standard deviation cannot be established from the posted record.

These gaps matter because a small study can be sensitive to which participants contribute measurements. In general, missingness may affect a result when the availability of an observation is related to participant characteristics or to the outcome itself. That possibility cannot be evaluated without information on missing observations and the analysis approach. The registry record does not report enough detail to determine how multiplicity, missing data, or analysis populations were addressed.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry reports serious adverse events and other adverse events separately for the two groups. For Non-Hunner IC, 5 participants were at risk for serious adverse events and 0 were affected; 5 were at risk for other adverse events and 0 were affected. For Hunner IC, 2 participants were at risk for serious adverse events and 0 were affected; 2 were at risk for other adverse events and 0 were affected. The record also lists 0 deaths. No top serious-event terms are listed.

These are the registry’s recorded event counts and denominators. They describe what was reported during the recorded safety assessment; they should not be read as proof that the procedure has no risk. With a small number of participants, zero recorded events does not rule out events that were not observed in the study or establish how often an event might occur in a broader population. The record does not provide further detail on the safety observation period or adverse-event collection methods, so those aspects cannot be assessed.

Serious and other adverse events are distinct categories in the registry. The zero counts in both categories are not efficacy findings and do not provide information about the primary permeability outcome. They should be interpreted as safety reporting for the participants listed as at risk, not as a comparison showing that one phenotype group is safer than the other.

13. What the Result Does, and Does Not, Mean

The record describes a completed study designed to examine whether an MRI-based bladder-permeability measure can characterize IC/BPS participants grouped by Hunner lesion status. It identifies the imaging procedure, the two cystoscopy-defined groups, the continuous primary endpoint, and its assessment time. It also records an overall enrollment of 7. These registry entries establish the study’s broad question and design, but they do not reveal the primary outcome findings.

The posted record does not report group means, standard deviations, a difference between groups, confidence intervals, or a p-value. Therefore, it cannot support a statement about the direction or size of any observed permeability contrast, the precision of an estimate, or whether a statistical test met a significance threshold. Missing numerical results are not evidence of no difference, and background rationale about preliminary observations is not a substitute for study results.

Even if a group contrast were available, its interpretation would need to reflect the design. Participants were categorized according to cystoscopy findings rather than randomly assigned to groups. Any observed association would describe the enrolled participants and would not, by itself, show that lesion status caused a change in permeability. Nor would a difference in group averages establish that the MRI assay can reliably classify individual patients. The registry does not report diagnostic performance, a threshold, or validation results.

The endpoint’s artificial-unit scale and the wording about brighter bladder walls and darker bladder centers also require careful interpretation. The registry describes how signal appearance relates to absorption, but does not provide enough detail to resolve the stated relationship between these image features. Without numerical measurements and fuller methods, the practical meaning of any change in the scale cannot be evaluated.

The appropriate conclusion is limited to what the record documents: a small, completed phenotype-imaging study was registered, with safety counts reported and a primary outcome specified. The numerical primary-outcome result and key analysis details are not reported in the registry record. No claim about the success, failure, or diagnostic usefulness of the assay follows from the information available.

14. Why This Trial Matters Statistically

This study raises a statistical question that is common in clinical imaging research: whether a continuous signal can distinguish groups defined by a clinical phenotype. A clearly specified measure and assessment time are important because they make the intended comparison more concrete. Here, the endpoint is bladder permeability in artificial units at 12 min image post-contrast, and the groups are defined by cystoscopy findings before ICE-MRI.

Statistically, however, defining an outcome is only one part of evaluating a study. Interpretation also requires the observed group values, the amount of variation, an estimate of the contrast, and information about its uncertainty. Those primary-outcome statistics are not reported in the registry record. The omission prevents readers from assessing whether a measured difference was large or small relative to the observed variability, and whether the estimate was precise or uncertain.

The phenotype-based design also matters. Non-Hunner IC and Hunner IC are not randomized arms, and the registry cautions that they are not a like-for-like control comparison. This distinction helps separate an association question from a treatment-effect question. A statistical contrast between the groups, if reported, would need interpretation in light of how participants were classified and any other differences between them.

The record illustrates why transparent reporting includes more than a study status and a named endpoint. Reporting analysis denominators, group summaries, a contrast with uncertainty, missing-data handling, and the analysis method would allow readers to evaluate the evidence more fully. It would also clarify whether the imaging measure’s numerical scale corresponds consistently to the described signal appearance.

The registry’s stated planning assumptions can be understood as design concepts, but no planning results or primary effect estimates are reported in the available record. Planning calculations cannot replace observed findings. The statistical importance of this study therefore lies in the question it sets out to examine and in the reporting information needed to answer it—not in a conclusion about the assay that the posted results do not provide.

15. 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 for statistical interpretation is that the registry record does not report numerical results for the primary endpoint. Group means, standard deviations, an estimated contrast, and uncertainty measures are unavailable. This prevents assessment of the direction, magnitude, and precision of the central comparison.

The enrollment is 7, but the record does not state the number of participants with usable primary-outcome measurements or the group-specific analysis denominators. It also does not report participant-level data, missingness, exclusions, or how incomplete imaging was handled. The analysis population therefore cannot be reconstructed from the registry record.

The two arms are defined by the presence or absence of a Hunner lesion on cystoscopy, and the registry states that allocation is not stated and the arms are not a like-for-like control comparison. This limits causal interpretation. The record does not describe adjustment for other participant characteristics or identify a method for controlling confounding.

Several statistical and measurement details are not reported in the registry record, including the specific comparison method, confidence-interval method, multiplicity handling, and missing-data strategy. The endpoint description also connects higher absorption with a brighter bladder wall and higher artificial-unit values, while separately referring to a darker bladder center as evidence of elevated absorption. The record does not explain how these descriptions relate to one another or provide detailed image-processing information.

Finally, no diagnostic threshold, classification accuracy, or independent validation result is reported. The study summary’s reference to preliminary data is background rationale and does not supply the primary outcome findings for this study. These limitations mean the registry supports a description of the study question and design, but not a quantitative judgment about the assay’s performance or the observed group contrast.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Phenotyping Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) by Intravesical Contrast Enhanced - Magnetic Resonance Imaging (ICE-MRI) Bladder Permeability Assay — NCT05811377.
• Registry record last updated 2026-07-10; status last verified 2026-07.
• Results first posted 2026-07-10.
• 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.

19. Record Summary

NCT05811377 is a completed study of intravesical contrast-enhanced MRI for phenotyping interstitial cystitis/bladder pain syndrome. The registry records an enrollment of 7, a start date of 2023-03-29, and a primary completion date of 2025-02-07. Participants were grouped as Non-Hunner IC or Hunner IC based on cystoscopy before ICE-MRI, with Gadobutrol and Ferumoxytol listed as diagnostic-test interventions.

The primary endpoint is continuous bladder permeability in artificial units, summarized by a mean and standard deviation at 12 min image post-contrast. The registry lists one outcome measure and one analysis, but does not report the numerical primary-outcome results, analysis denominators, or specific analysis method. Safety reporting lists 0 serious adverse events, 0 other adverse events, and 0 deaths in the recorded group entries. These counts do not establish the primary outcome or rule out risk beyond the recorded study observations.

The record supports a description of the intended phenotype comparison, but does not allow the size or precision of a primary-outcome difference to be assessed.