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 Estimation of CSF Pressure Using MRI in Patients With Spontaneous Intracranial Hypotension (NCT03041441), a na na study. The primary outcome is Intracranial Pressure Measurements Estimated by the MRICP Technique..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03041441 |
| Phase | NA |
| Condition | Intracranial Hypotension |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 5 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Duke University |
| Results posted | Yes |
2. Clinical Question
Population
Patients with spontaneous intracranial hypotension, a condition described in the study summary as caused by leakage of the fluid surrounding the brain and spine. The registry record lists intracranial hypotension as the condition and records enrollment of 5 participants. It does not report demographic or clinical characteristics of the participants.
Intervention
The study examines an MRI algorithm, called the MRICP method, that estimates intracranial pressure using MRI measurements related to cranial blood and cerebrospinal fluid movement. Lumbar puncture and epidural patching are also listed as procedures. The record describes an interest in whether estimated pressure changes after treatment, but does not report treatment-specific results.
Comparator
No concurrent control group or randomized comparison is described. The study is classified as single-group, and allocation is recorded as NA. The MRI estimate is discussed in relation to pressure measurement and possible change after treatment, but the registry record does not define a like-for-like control comparison.
Primary question
The primary question is whether intracranial pressure can be estimated using the MRICP technique during a scan. The listed primary outcome is a number expressed in cm H20, measured during a scan lasting approximately 30 minutes. The registry record does not report the numerical estimate or its distribution.
3. Trial Design
This is a completed, single-group study sponsored by Duke University. The registry records enrollment of 5 and lists the phase as NA. Allocation is also NA, and masking is recorded as NONE. These design details describe a study without a randomized, masked comparison between treatment groups; they do not establish how any individual participant was managed.
The study title and summary identify its focus as non-invasive estimation of cerebrospinal fluid pressure using MRI in patients with spontaneous intracranial hypotension. The listed interventions are an MRI algorithm, lumbar puncture, and epidural patching. The summary says the study aims both to estimate intracranial pressure with MRI and to determine whether the estimate changes after treatment. The record does not report a comparison group or specify a treatment-effect estimate.
The registry lists the study start as 2017-09-14 and primary completion as 2019-10-25, with status COMPLETED. These dates describe the recorded study timeline, not the timing or completeness of outcome reporting. The registry describes the primary measurement as occurring during a scan, approximately 30 minutes.
The record does not report a protocol-level statistical analysis plan, a sample-size justification, or interim analyses. It lists 5 outcome measures and 0 analyses. Those entries do not provide numerical outcome results. In particular, the study's single-group classification should not be confused with a controlled comparison, and the mention of lumbar puncture or epidural patching does not itself establish that MRI estimates were compared against those procedures.
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
| Stage | MRICP Method |
|---|---|
| STARTED | 5 |
| COMPLETED | 3 |
| NOT COMPLETED | 2 |
Analysis population for the primary outcome, as defined in the registry: Data not collected on 4 participants.
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 | MRICP Method |
|---|---|---|
| Participants analysed | 5 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 3 |
| Age, Categorical: >=65 years | Participants | 2 |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 3 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 4 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 1 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 5 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | Participants | 5 |
6. Primary Endpoint
The registry lists the primary outcome as Intracranial Pressure Measurements Estimated by the MRICP Technique., measured over During scan, approximately 30 minutes.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | cm H20 |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is titled “Intracranial Pressure Measurements Estimated by the MRICP Technique.” It is recorded as a number in cm H20, with measurement during a scan lasting approximately 30 minutes. The description says that momentary differences between blood and cerebrospinal fluid entering and leaving the cranium during the cardiac cycle are used to estimate intracranial volume change; a pressure difference is then estimated using the derivative of cerebrospinal fluid velocities.
The endpoint is relevant to the stated purpose because it represents the pressure estimate produced by the MRI-based method. It is an estimated measurement, rather than a reported clinical event or a direct treatment comparison. The registry record does not report the numerical endpoint value, variability, confidence interval, or a comparison with another measurement method. It also says data were not collected on 4 participants. The record does not explain the reason for that missing collection or provide enough outcome information to assess the precision or agreement of the method.
In general, a measurement endpoint can describe what a method produces, while evidence about accuracy or agreement requires an appropriate reference measurement and analysis. The registry record does not report such an analysis. Therefore, the endpoint description explains how the estimate is intended to be formed, but does not establish how closely it corresponds to another pressure measurement.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the study's purpose and design, but does not report numerical primary-outcome results. It describes an MRI-based estimate of intracranial pressure in patients with spontaneous intracranial hypotension and an interest in whether estimated pressure changes after treatment. The primary endpoint is a number in cm H20 measured during a scan, approximately 30 minutes. No estimated pressure value, measure of variability, or inferential result is reported in the registry record.
This absence matters for interpretation. Without the endpoint values, readers cannot assess the range or typical level of the estimates, their precision, or whether participants' estimates changed. The statement that data were not collected on 4 participants also identifies missing outcome data, but does not explain why they were missing or provide a method for handling them. The registry record does not report an analysis population or a statistical analysis of the primary endpoint.
The design is single-group, allocation is NA, and masking is NONE. These features do not support interpreting the record as a randomized comparison of MRI against a control group. The study summary mentions possible assessment of change after treatment, but the registry record does not report a numerical change estimate or a treatment comparison. A stated research objective is not itself evidence that a change was observed.
There are 5 outcome measures and 0 analyses listed. Three secondary outcomes are named: change in intracranial pressure estimated with the MR technique, change in transverse venous sinus caliber, and change in flow velocity through the transverse dural venous sinus. The registry record does not report results for these outcomes or explain how multiple outcomes were handled statistically.
Safety entries record 5 at risk, 0 serious events, 0 other events, and 0 deaths for the MRICP Method group. These are the entries in the registry; they should not be expanded into a claim that no possible adverse effects occurred. The record does not supply event details beyond those counts.
Overall, the posted information supports describing the study's intended measurement and basic design, not judging the performance of the MRI method or the effect of treatment. A reader cannot recover accuracy, agreement, change, or statistical significance from the information recorded. Any interpretation beyond the stated objectives and registry entries would require results or analyses that are not reported in the registry record.
9. Statistical Methods Explained
What does the MRI estimate represent?
The study description presents the MRICP method as an estimate based on cerebrospinal fluid physiology. It describes measuring momentary differences between blood and cerebrospinal fluid entering and leaving the cranium over the cardiac cycle, using these to estimate intracranial volume change, and estimating a pressure difference from the derivative of cerebrospinal fluid velocities. This explains the intended measurement process. It is not, by itself, a validation result or evidence of agreement with another method.
In general, a measurement method can be evaluated by comparing its results with an appropriate reference, examining agreement and uncertainty, and considering whether repeated measurements are consistent. Those are general statistical considerations; the registry record does not report such analyses for this study. It also does not report the numerical pressure estimates or a measure of their spread.
What can a single-group design establish?
The study is classified as single-group, with allocation recorded as NA and masking as NONE. In general, a single-group design can describe measurements made in the enrolled group, but a change observed over time can be difficult to distinguish from other explanations without an appropriate comparison. A randomized comparison is not recorded. The registry's description of possible change after treatment therefore states a question of interest, not a causal result.
The listed interventions include the MRI algorithm, lumbar puncture, and epidural patching. The record does not explain how these procedures were sequenced or whether all were used for each participant. The intervention list alone cannot establish a reference-standard comparison, an assignment process, or a treatment-effect analysis.
How should uncertainty be understood?
In general, an estimate from a study is more informative when accompanied by a measure of uncertainty. A confidence interval is one way to express uncertainty around an estimated quantity: it describes a range of values compatible with the data and a specified statistical procedure. It does not guarantee that the true value lies within that range, and its interpretation depends on the method and assumptions used.
The registry record does not report a confidence interval, standard error, or other measure of variability for the primary endpoint. It also does not report the endpoint value itself. Consequently, precision cannot be assessed from the posted registry information. The enrollment entry is 5, while the primary-outcome description says data were not collected on 4 participants; the record does not say how the available endpoint data were analyzed.
What does over-dispersion mean in general?
Over-dispersion is a general concern when observed variation in data is greater than a statistical model assumes. If a model understates that variation, standard errors may be too small and confidence intervals too narrow. Whether over-dispersion is relevant depends on the outcome type and analysis. The primary endpoint is described as a number, but no model, distributional assumption, or analysis is reported. There is therefore no basis in the registry record to say whether over-dispersion was assessed or relevant in the actual analysis.
How should planning illustrations be read?
Any planning sample-size illustrations associated with the study are not observed study results. The stated illustration assumptions use 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. The stated convention is participants per arm for outcomes other than time-to-event outcomes. These are planning assumptions, not evidence that the study used a two-arm design or achieved a particular power.
The design recorded for this study is single-group, while those illustration assumptions describe equal allocation between two arms. That distinction is important: a planning illustration cannot be treated as the study's actual design, a retrospective measure of observed power, or a result. The registry record does not report the study's own sample-size justification or statistical plan. The planning assumptions also do not fill in missing outcome values or establish the MRI method's accuracy.
What analysis details are available?
The registry lists 5 outcome measures and 0 analyses. It does not report an inferential model, adjustment variables, missing-data method, or analysis population. In general, statistical analyses should be interpreted in light of their prespecified methods, outcome definitions, and assumptions. Without those details and without numerical results, readers cannot determine how estimates were calculated or assess their robustness.
The record names secondary outcomes concerning estimated pressure, transverse venous sinus caliber, and flow velocity through the transverse dural venous sinus. It does not report numerical results for them. A list of outcomes identifies intended measurements, but does not show whether they were successfully measured, analyzed, or found to change.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 5 outcome measures and 0 analyses. It names a primary outcome and three secondary outcomes: change in intracranial pressure estimated with the MR technique, change in transverse venous sinus caliber, and change in flow velocity through the transverse dural venous sinus. The record does not report results for these outcomes or identify how any additional outcome measures relate to the named ones.
When a study examines multiple outcomes, the chance of obtaining an apparently notable result can increase if many statistical tests are considered. In general, researchers may address this through a prespecified hierarchy, adjusted testing, or clear emphasis on a primary outcome. The registry record does not report a multiplicity strategy, so it is not possible to determine whether or how multiple testing was addressed.
Missing data are directly relevant: the primary outcome description states that data were not collected on 4 participants. The reason, timing, and handling of this missingness are not reported in the registry record. It does not state whether missingness was related to participant characteristics or study procedures, nor whether any imputation or sensitivity analysis was used. These details matter because analyses based only on available measurements can be biased if the missingness is related to the outcome.
The registry record also does not define an analysis population, such as which participants were included in each outcome analysis. With 0 analyses listed and no numerical outcome results, the data available for any estimate and the handling of missing observations cannot be assessed.
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 |
|---|---|---|---|
| MRICP Method | 0 | 5 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| MRICP Method | 0 of 5 |
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 |
|---|---|
| MRICP Method | 0 of 5 |
For the MRICP Method group, the registry lists 5 participants at risk, 0 serious adverse events, 0 other adverse events, and 0 deaths. These are the safety counts recorded for this group. The record lists no top serious-event terms.
These entries should be read as registry-reported counts, not as proof that no adverse event of any kind occurred. The record does not provide event descriptions, timing, severity details beyond the serious-event category, or a separate safety analysis. It also does not explain how safety information was collected or how long participants were followed for safety reporting.
In general, a count of zero recorded events is distinct from evidence that an intervention has no risk. Interpretation depends on the amount and duration of observation, completeness of reporting, and the definition of an event. Those details are not reported in the registry record. The counts therefore describe the posted safety entries and should not be used to make broader conclusions about safety.
12. What the Result Does, and Does Not, Mean
This record documents a completed, single-group study designed to estimate intracranial pressure using an MRI-based method in patients with spontaneous intracranial hypotension. It gives a description of how the MRICP estimate is intended to be generated and identifies a primary endpoint measured in cm H20 during a scan of approximately 30 minutes. It also records an interest in whether estimated pressure changes after treatment.
What the record does not provide is just as important: there is no numerical primary-outcome result, no reported statistical analysis, and no reported estimate of change after treatment. The primary endpoint description states that data were not collected on 4 participants, while the reason and analytical handling are not reported. The registry record therefore does not show the size, precision, or direction of any observed pressure estimate or change.
The design information does not establish a controlled comparison. The study is single-group, allocation is NA, and masking is NONE. Without a reported comparison against an appropriate reference or control, the registry information cannot establish the method's accuracy, agreement with another measurement, or a treatment effect. The objectives and measurement description should not be mistaken for outcome evidence.
The safety entries record no serious events, other events, or deaths in the MRICP Method group, among 5 at risk. These counts are limited to the registry entries and do not establish absence of risk. More complete safety methods and follow-up details are not reported in the registry record.
Accordingly, the record is informative about the study question, procedures listed, and limitations in outcome reporting. It does not support a conclusion about whether the MRI method performs well or whether treatment changes intracranial pressure. Such conclusions require results and analyses that are not reported in the registry record.
13. Why This Trial Matters Statistically
This study is statistically interesting because it focuses on a measurement rather than a conventional comparison of assigned treatments. The primary endpoint is an MRI-derived number intended to estimate intracranial pressure. For a measurement method, the central statistical questions often concern the estimate's uncertainty, repeatability, and agreement with an appropriate reference. The registry describes the intended calculation but does not report results needed to assess those properties.
The single-group design is also important. A record of a possible before-and-after question does not by itself separate treatment-related change from other sources of change. The registry does not report a comparison group, a numerical change estimate, or an analysis of the change. That distinction helps keep the interpretation aligned with the study structure rather than implying a randomized treatment comparison.
Missing endpoint data affect what can be learned: the primary outcome description says data were not collected on 4 participants. The record does not state why or how this was handled. In general, missingness can limit precision and may affect interpretation if the availability of measurements is related to the outcome. Without analysis details, that possibility cannot be evaluated.
Finally, the record lists multiple outcomes but 0 analyses. This highlights the difference between registering a measurement objective and presenting an analysis. Statistical interpretation requires outcome values, uncertainty, and a transparent account of methods. The available record is therefore useful for understanding the intended measurement framework, while leaving its empirical performance unresolved.
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 primary limitation in interpreting this particular record is that numerical outcome results are not reported. The primary endpoint is described as a number in cm H20, but no estimate or measure of variability appears in the registry record. Without these, the performance and precision of the MRI-based estimate cannot be judged.
The primary outcome description states that data were not collected on 4 participants. The record does not report the reason, whether the missingness arose during scanning or elsewhere, or how missing data were handled. It also does not identify the analysis population. This leaves uncertainty about which available observations, if any, contributed to an estimate.
The study is single-group, with allocation recorded as NA and masking as NONE. The record does not describe a concurrent control group or a reported comparison against another pressure measurement. It therefore does not provide the information needed to assess agreement or distinguish change after treatment from other explanations.
The registry lists 5 outcome measures and 0 analyses, but does not report results for the primary or named secondary outcomes. A statistical analysis plan, multiplicity approach, sample-size justification, and interim analyses are not reported in the registry record. These absences limit assessment of how the measurements were intended to be analyzed and how robust any conclusions might be.
Safety reporting is limited to the recorded event counts for the MRICP Method group. Further details about event definitions, ascertainment, and follow-up are not reported in the registry record. The available safety entries should therefore be interpreted narrowly.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Non-invasive Estimation of CSF Pressure Using MRI in Patients With Spontaneous Intracranial Hypotension — NCT03041441.
- Registry record last updated 2020-07-28; status last verified 2020-07.
- Results first posted 2020-07-28.
- 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
NCT03041441 is a completed, single-group study sponsored by Duke University. The registry records enrollment of 5, phase NA, allocation NA, and masking NONE. The study concerns MRI-based estimation of intracranial pressure in patients with spontaneous intracranial hypotension. The recorded study start is 2017-09-14, and primary completion is 2019-10-25.
The primary outcome is a numerical intracranial pressure estimate in cm H20 during a scan, approximately 30 minutes. The record states that data were not collected on 4 participants. It lists 5 outcome measures and 0 analyses, but does not report numerical outcome results or statistical analyses. Safety entries for the MRICP Method group record 5 at risk, 0 serious events, 0 other events, and 0 deaths.