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 Massive Iron Deposit Assessment (NCT01572922), a na na study. The primary outcome is Hepatic Iron Content in the Liver Using Liver Biopsy.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01572922 |
| Phase | NA |
| Condition | Iron Overload, Excessive Body Iron Burden |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 142 |
| Arms in the primary outcome | n/a |
| Lead sponsor | St. Jude Children's Research Hospital |
| Results posted | Yes |
2. Clinical Question
Population
People with iron overload or excessive body iron burden. The primary outcome population is narrower: eligible participants with both a liver biopsy measurement and a 1.5T R2*-UTE measurement.
Intervention
R2*-UTE MRI, a technique intended to measure hepatic iron when iron burden is large. Participants also underwent R2*-GRE MRI; liver biopsy was included if clinically indicated.
Comparator
The principal reference measurement is hepatic iron content from liver biopsy. This is a within-participant measurement comparison, not a comparison between randomized treatment groups.
Primary question
Can the 1.5T R2*-UTE MRI measurement assess liver iron in participants with iron overload, in relation to hepatic iron content measured by biopsy? The registry describes this aim but does not report the primary outcome result.
The clinical motivation in the registry is that repeated transfusions can lead to iron accumulation in organs, while MRI measures may be limited at high hepatic iron concentrations. The study focuses on whether UTE MRI can measure liver iron in people with large amounts of iron and compares the MRI result with biopsy from the same participant. This is a measurement question: it concerns how an imaging measurement relates to a tissue-based measurement, rather than whether a treatment changes health outcomes.
Biopsy was not described as required for every participant. The record says it was performed if clinically indicated, and the primary outcome population includes only participants with both the biopsy and UTE measurements. The number meeting that joint-measurement definition is not reported in the registry record. Nor are the paired measurement values or an estimate of their relationship reported in the registry record.
3. Trial Design
The registry describes a completed, single-group study with enrollment of 142 participants. It lists iron overload and excessive body iron burden as conditions, and identifies St. Jude Children's Research Hospital as the sponsor. The study start date is 2012-06-11 and the primary completion date is 2018-02-28. The listed masking is none, and the allocation and phase are recorded as NA.
The study procedures include R2*-UTE MRI and R2*-GRE MRI. Liver biopsy was included when clinically indicated. The primary outcome concerns hepatic iron content measured by biopsy in eligible participants who also had a 1.5T R2*-UTE measurement. Its timeframe is up to 30 days after MRI. The record also lists secondary outcomes involving MRI-derived R2* measurements and serum iron or transferrin saturation measurements.
This design is not a randomized comparison of treatment arms. It is described as a single group, and the registry notes that its arms are not a like-for-like control comparison. The study can therefore address the planned measurement relationship only to the extent that the relevant paired measurements were obtained and analyzed; it cannot, on this design description, establish a treatment effect against a randomized control group.
The brief summary gives an overall accrual of 200 patients and estimates patient accrual at 150, including an estimate that 41 would have a clinical indication for biopsy. These are accrual statements in the record, not outcome counts. The record separately reports enrollment of 142. The protocol details behind these different accrual figures, including the final number with biopsy measurements, are not reported in the registry record. A detailed recruitment pathway, eligibility criteria, and the reasons participants may not have had both measurements are also not reported in the registry record.
The registry record does not describe a statistical analysis plan, the timing of any interim analyses, or a sample-size justification for the study's own design. Those details should not be inferred from the presence of outcome descriptions or from any planning illustrations.
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: One arm study
Overall Study
| Stage | Arm 1 |
|---|---|
| STARTED | 142 |
| COMPLETED | 139 |
| NOT COMPLETED | 3 |
Reasons for not completing this period:
| Reason | Arm 1 |
|---|---|
| Adverse Event | 1 |
| Protocol Violation | 1 |
| Death | 1 |
Analysis population for the primary outcome, as defined in the registry: Eligible iron-overloaded patients with both liver biopsy measurement and 1.5T R2\*-UTE measurement.
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 | Arm 1 |
|---|---|---|
| Participants analysed | 142 | |
| Age, Categorical: <=18 years | Participants | 85 |
| Age, Categorical: Between 18 and 65 years | Participants | 57 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 15.9 (1.5 to 53.6) |
| Sex: Female, Male: Female | Participants | 79 |
| Sex: Female, Male: Male | Participants | 63 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 8 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 131 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 3 |
| Race/Ethnicity, Customized: Asian | Participants | 10 |
| Race/Ethnicity, Customized: Black or African American | Participants | 85 |
| Race/Ethnicity, Customized: White | Participants | 40 |
| Race/Ethnicity, Customized: More than one race | Participants | 1 |
| Race/Ethnicity, Customized: Unknown or Not Reported | Participants | 6 |
| Region of Enrollment: United States | Participants | 142 |
6. Primary Endpoint
The registry lists the primary outcome as Hepatic Iron Content in the Liver Using Liver Biopsy, measured over up to 30 days after MRI.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Full Range |
| Unit | mcg |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is hepatic iron content in the liver measured using liver biopsy. The registry reports the unit as mcg and specifies that the result is summarized as a median with the full range. The stated timeframe is up to 30 days after MRI. The primary outcome population consists of eligible iron-overloaded participants with both a biopsy measurement and a 1.5T R2*-UTE measurement.
Biopsy provides a tissue-based measure of hepatic iron. In this study's stated purpose, it serves as the reference against which the MRI measurement can be considered. Pairing the MRI and biopsy measurements from the same participant is important for a measurement comparison because the two values then relate to the same person's liver rather than to separate groups. The registry description does not report the paired values, an agreement estimate, or a result showing how closely the MRI measurement corresponds to biopsy.
General statistical context: a median describes the middle of an ordered set of measurements and is less affected by very large or very small observations than a mean can be. A full range describes the lowest and highest observed values, but does not show how values are distributed between those extremes. Neither summary alone establishes whether two measurement methods agree closely for individual participants. The registry record reports the intended summary format, but not the primary endpoint's observed median or range.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the study's measurement objective and design, but it does not report a primary outcome value. The biopsy-based hepatic iron content is identified as the primary endpoint, with a median and full range as the intended summary. The result itself, including the number of eligible participants contributing paired biopsy and UTE measurements, is not reported in the registry record. Consequently, the degree of correspondence between R2*-UTE and biopsy cannot be assessed from the reported results.
The record lists secondary outcome topics, including R2* measured by 1.5T GRE and UTE techniques, and outcomes involving serum iron and transferrin saturation. It does not provide numerical results for these outcomes in the registry record. No effect estimates, uncertainty intervals, test statistics, or p-values are reported in the registry record. Without those results, there is no basis for describing the size or precision of an observed measurement relationship.
The study's single-group structure is consistent with its stated measurement purpose, but it is not a randomized treatment comparison. Differences between measurement methods, if analyzed, would concern measurement performance rather than a causal effect of treatment. The registry does not report an analysis that quantifies bias, agreement, or accuracy, and it does not state a threshold for deciding whether a measurement is sufficiently close to biopsy.
General statistical context: estimates from paired measurements can describe whether two methods tend to yield similar values, but correlation alone is not the same as agreement. Two methods may move together across participants yet still give systematically different readings. An agreement assessment generally needs to consider the size and pattern of within-participant differences, along with uncertainty. These are general principles, not a description of analyses reported for this study.
The registry lists 7 outcome measures and 0 analyses. That listing does not establish that no analyses were performed outside the registry; it means the registry record does not provide analysis results to interpret. Planning sample sizes are design illustrations, not observed power. The registry's planning assumptions refer to an effect based on the observed effect, but numerical planning outputs and the observed effect are not reported in the registry record. They cannot substitute for a reported endpoint estimate or its precision.
Overall, the registry supports a description of the intended comparison—UTE MRI measurement against biopsy in participants with both measurements—but not a conclusion about the result. The number enrolled is not the same as the number contributing to the primary endpoint. The latter, and the measurement estimates needed to judge precision, are not reported in the registry record.
9. Statistical Methods Explained
General statistical context: the design described is a single-group measurement study. Each participant's MRI measurement is intended to be considered alongside that participant's biopsy measurement, when biopsy was clinically indicated. This differs from a randomized trial that assigns participants to competing treatments. The relevant statistical question is how two measurement methods relate, not whether one treatment changes an outcome compared with another treatment.
What does a median with a full range describe?
The registry specifies a median and full range for the biopsy-based hepatic iron content endpoint. A median locates the center of an ordered set of observed values. The full range gives the endpoints of the observed values. These summaries can convey the central location and spread in a compact way, but they do not reveal the shape of the distribution or how densely observations occur at different values. They also do not, by themselves, quantify the relationship between biopsy and MRI.
The endpoint unit is mcg. The timeframe is up to 30 days after MRI, so the intended biopsy measurement is temporally related to the imaging measurement. The registry does not report the actual interval for each participant or an analysis of whether the interval affected the comparison. The result values and the number of paired observations are not reported in the registry record.
Why distinguish association from agreement?
General statistical context: association describes whether measurements tend to vary together across participants. Agreement concerns whether values from two methods are close enough to be treated as comparable. A strong association can coexist with a consistent offset between methods, so association alone is not enough to establish interchangeability. Measurement comparisons may examine paired differences, systematic bias, and how the differences vary across the measurement range. The registry record does not report whether these methods were used.
Precision also matters. An estimate from a limited set of paired measurements may be uncertain, and a range of plausible values helps readers assess that uncertainty. A confidence interval is a general statistical tool for expressing uncertainty around an estimate under the assumptions of the analysis. The registry record does not report confidence intervals for the primary outcome or for a comparison between MRI and biopsy. No uncertainty measure for the measurement relationship is reported in the registry record.
What can over-dispersion mean?
General statistical context: over-dispersion occurs when the variability in data is greater than a statistical model expects. If a model does not account for that extra variability, its uncertainty estimates can be too small and inferential results can appear more precise than warranted. Whether over-dispersion is relevant depends on the data type and model. The registry record does not report a model or indicate that over-dispersion was assessed, so this general issue should not be read as a finding about this study.
What is known about the analysis plan?
The registry identifies the primary outcome's summary format and its eligible population, but it does not report a detailed statistical analysis plan. Model choice, covariate adjustment, handling of values outside the measurement range, diagnostic checks, and criteria for interpreting agreement are not reported in the registry record. The record also does not state whether any interim analyses were planned or conducted. These details cannot be reconstructed from the endpoint description alone.
The registry lists secondary outcomes concerning 1.5T GRE and UTE R2* measurements, and serum iron and transferrin saturation. It does not report statistical methods or analysis results for those outcomes. In a study with multiple outcomes or comparisons, multiplicity can affect how evidence is interpreted because repeated testing can increase the chance of a nominally notable result. General approaches include prespecifying a primary question or adjusting inference across a defined family of tests. The registry does not report a multiplicity strategy.
The record reports 7 outcome measures and 0 analyses. This is a description of what is listed in the registry, not evidence that no work was performed elsewhere. The stated planning illustration uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Those are planning assumptions, not a description of the single-group measurement analysis, and they do not establish observed power. The registry record does not report the study's own sample-size justification or numerical planning results.
Finally, interpretation depends on which participants contribute usable paired measurements. The primary population is defined by having both biopsy and UTE measurements, while biopsy was conditional on clinical indication. The number with both measurements, the number excluded from the primary analysis, and the handling of missing or unusable measurements are not reported in the registry record. Without these details, readers cannot assess how closely the analyzed population reflects all enrolled participants.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 7 outcome measures, including the biopsy-based primary outcome and secondary MRI and blood-measurement outcomes. It lists 0 analyses. No adjustment for multiple outcomes or repeated statistical tests is reported in the registry record. The registry also does not specify which secondary outcomes, if any, were considered confirmatory. Without an analysis plan, the intended family of tests and the approach to multiplicity cannot be determined.
General statistical context: when several hypotheses are tested, interpreting each result as if it were the only test can overstate the evidence associated with an isolated small p-value. A prespecified hierarchy or adjustment can help control this issue, but the appropriate approach depends on the aims and analysis plan. This is general guidance about interpretation; no multiplicity procedure is reported for this study.
The primary endpoint population requires both a biopsy measurement and a 1.5T R2*-UTE measurement. Because biopsy was performed if clinically indicated, this population may not include every enrolled participant. The number meeting the paired-measurement definition is not reported in the registry record. The record also does not report missing-data methods, exclusions, imputation, or sensitivity analyses. It is therefore not possible to determine from the registry how incomplete or unusable measurements were handled.
Analysis populations beyond the eligibility description for the primary endpoint are not reported in the registry record. There is no reported participant flow detailing who contributed to each outcome or analysis. The stated enrollment of 142 should not be assumed to equal the number included in the primary endpoint analysis.
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 |
|---|---|---|---|
| Iron-overloaded Patients | 1 | 142 | 0.7% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Iron-overloaded Patients | 1 of 142 |
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 |
|---|---|
| Iron-overloaded Patients | 2 of 142 |
Most frequent serious adverse event terms
| Event term | Organ system | Iron-overloaded Patients |
|---|---|---|
| Infections and infestations | Gastrointestinal disorders | 1 of 142 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Iron-overloaded Patients |
|---|---|---|
| Anxiety | Psychiatric disorders | 1 of 142 |
| abdominal pain | Gastrointestinal disorders | 1 of 142 |
Serious events with the highest arm-level rate: infections and infestations (0.7%).
The registry lists an iron-overloaded group with 142 participants at risk for serious adverse events and 1 participant affected. It also lists 142 at risk for other adverse events and 2 affected, along with 1 death. These are registry counts; they do not establish that an event was caused by an MRI procedure, biopsy, or any other study activity. Attribution and event-level details are not reported in the registry record.
Infections and infestations are listed among the top serious adverse event terms at 0.7%. The registry entry does not provide enough detail to infer the timing, severity, outcome, or relationship to study procedures for each event. The record also does not clarify whether the listed event categories overlap, so the affected counts should not be combined or treated as mutually exclusive.
General statistical context: safety counts describe events recorded under the registry's definitions and observation period. Their interpretation depends on the event definitions, duration of follow-up, completeness of reporting, and whether events were attributed to the study. Those details are not reported in the registry record. The listed counts should therefore be read descriptively, not as evidence of cause or as a comparison between treatments.
12. What the Result Does, and Does Not, Mean
The record describes a study intended to assess whether R2*-UTE MRI can measure liver iron in people with large amounts of iron, using liver biopsy from the same participant as a reference when clinically indicated. It also describes R2*-GRE MRI and additional outcomes involving MRI-derived measurements, serum iron, and transferrin saturation. These details establish the study's measurement focus, not the success or failure of the method.
The registry does not report the primary endpoint's observed median or full range, the number of paired measurements, or a statistical estimate comparing MRI and biopsy. It also does not report uncertainty intervals or an analysis of agreement. As a result, the posted information cannot show how close the UTE measurements were to biopsy values, how precisely any relationship was estimated, or whether performance differed across levels of hepatic iron.
The study is single-group and is not a randomized comparison of treatment groups. Its results, if reported, would address measurement properties in the studied participants rather than the causal effect of a treatment. The registry's stated purpose should not be mistaken for an observed result, and the enrollment count should not be mistaken for the number with complete data for the primary endpoint.
General statistical context: a measurement method can be evaluated for association, bias, precision, and agreement, and these are distinct properties. A result addressing one property does not automatically establish the others. The registry does not report estimates for these properties, so no such conclusion can be drawn from the record.
The record also does not establish how well findings would generalize beyond its enrolled population. Eligibility details and the final paired-measurement population are not reported in the registry record. The appropriate interpretation is therefore limited: the registry documents a completed study and its intended MRI-to-biopsy measurement question, but it does not provide the outcome data needed to answer that question.
13. Why This Trial Matters Statistically
This study addresses a statistical challenge in diagnostic measurement: evaluating an imaging measurement against a tissue-based reference in the same participant. Paired measurements are useful because each participant serves as the context for interpreting their own MRI and biopsy values, rather than relying on a comparison between unrelated groups. The registry's primary population explicitly requires both measurements.
The clinical background describes limits of existing MRI-based R2* approaches at high hepatic iron levels, motivating assessment of UTE MRI in participants with large iron burdens. Statistically, this makes the range and distribution of observed measurements important. A method's performance in one part of the measurement range need not describe its performance elsewhere. However, the registry record does not report outcome values or analyses by measurement level, so it cannot establish performance across the range.
The record also illustrates why a study objective and a result are different things. A clearly stated comparison does not itself provide evidence about agreement, bias, or precision. Readers need the paired data summaries and analysis results, as well as information about who contributed measurements, to evaluate the claim the study set out to examine. Those results and population details are not reported in the registry record.
General statistical context: good measurement evaluation depends on matching the analysis to the question. Correlation, agreement, calibration, and repeatability address different features of a measurement method. The choice of summary and uncertainty assessment should be specified in relation to the intended use of the measurement. The registry does not report such a detailed analysis plan, so these concepts explain the statistical issues rather than describe analyses conducted in this study.
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.
A central limitation of interpretation is that the registry record does not report the primary outcome result. The biopsy-based hepatic iron content median and full range are not reported, and no estimate of the relationship between biopsy and R2*-UTE is available. The number of participants with both measurements is also not reported in the registry record, so the size of the primary analysis population cannot be established from enrollment alone.
Biopsy was performed if clinically indicated, while the primary endpoint population requires biopsy and UTE measurements. This means that the primary analysis population is defined by measurement availability and clinical indication, but the record does not describe how that population was selected or how it compares with all enrolled participants. This limits assessment of representativeness and the possibility that the paired subset differs from other participants.
The registry does not report a detailed statistical analysis plan, agreement criteria, uncertainty estimates, missing-data handling, or adjustment for multiple outcomes. It also does not provide participant flow by outcome, details about unsuccessful or unusable scans, or the number of biopsies contributing to the primary endpoint. These omissions make it difficult to assess precision, possible selection effects, and the robustness of any measurement conclusion.
The study is single-group and not randomized, so it is not designed as a treatment-effect comparison. Its registry description supports a measurement objective but does not establish that the MRI method is interchangeable with biopsy or valid for every level of iron burden. The absence of reported results is the main limitation for interpreting the study's stated aim.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Massive Iron Deposit Assessment — NCT01572922.
- Registry record last updated 2019-06-11; status last verified 2019-04.
- Results first posted 2019-05-21.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT01572922, titled “Massive Iron Deposit Assessment,” is listed as completed. The registry reports enrollment of 142 participants, a study start date of 2012-06-11, and a primary completion date of 2018-02-28. The study is described as single-group, with no masking and allocation recorded as NA.
Its primary outcome is hepatic iron content measured by liver biopsy, summarized as a median with full range, in eligible participants with both biopsy and 1.5T R2*-UTE measurements. The timeframe is up to 30 days after MRI. Procedures include R2*-UTE, R2*-GRE, and biopsy if clinically indicated.
The registry lists 7 outcome measures and 0 analyses. It reports safety counts, but does not report the primary outcome values, the paired-measurement sample size, or statistical results for the MRI-to-biopsy question. The study's intended measurement comparison is described; its result is not reported in the registry record.