## Facts

- Kathleen Marsh was a paying passenger aboard a Celebrity Cruises vessel, the *Celebrity Solstice*.
- Marsh alleged she slipped and fell on a puddle of water in the ship’s Solarium area.
- Marsh sued Celebrity Cruises, Inc. in federal court, asserting maritime negligence based on an alleged failure to prevent and warn of a dangerous condition.
- Marsh claimed she suffered injuries including a mild traumatic brain injury (mild TBI) as a result of the fall.
- Marsh retained Dr. Gerald York, M.D., a neuroradiologist, to review her imaging and medical information.
- Dr. York interpreted Marsh’s diffusion tensor imaging (DTI) and concluded the DTI supported that Marsh sustained a mild TBI from the slip-and-fall.
- Celebrity Cruises did not challenge Dr. York’s credentials but moved to exclude his DTI-related opinions under Federal Rule of Evidence 702 and *Daubert*, arguing DTI was unreliable “junk science” and that York’s conclusions were speculative and unhelpful to a jury.
- The decision at 2017 WL 6987718 is an evidentiary ruling on Celebrity’s motion to strike/exclude Dr. York’s DTI testimony, not a merits ruling on negligence or causation at trial.

## Issues

1. Whether, under Federal Rule of Evidence 702 and the *Daubert* standard, Dr. York could testify about DTI results and his opinion that Marsh sustained a mild TBI from the fall, or whether that testimony had to be excluded as unreliable or unhelpful.

## Decision

- The court denied Celebrity Cruises’ Rule 702/*Daubert* motion to exclude Dr. York’s DTI testimony.
- The court found the proposed DTI testimony sufficiently reliable for admission, relying on evidence that DTI has extensive peer-reviewed research support, is used by medical institutions, and is associated with a low error rate.
- The court concluded Dr. York’s testimony would help the jury evaluate whether Marsh suffered a mild TBI and whether imaging findings were consistent with her claimed injury mechanism.
- The court held that Celebrity’s objections—such as disputes about DTI protocols, acquisition variables, and interpretive disagreements—were matters for cross-examination and competing proof, not a basis for exclusion under Rule 702.

## Legal Principles

- Under Federal Rule of Evidence 702, expert testimony is admissible when the witness is qualified, the methodology is reliable, the methods are reliably applied to the facts, and the testimony helps the trier of fact.
- Under *Daubert*, courts act as gatekeepers by evaluating reliability using factors such as testability, peer review and publication, known or potential error rate, standards controlling the technique’s operation, and acceptance within the relevant scientific community.
- Scientific evidence is not excluded merely because it is disputed; where a method has adequate scientific support and a proper foundation, disagreements about inputs, protocols, and interpretation generally go to weight rather than admissibility.
- Medical-imaging testimony may be admitted when it supplies specialized information beyond ordinary juror knowledge and is tied to the facts of the plaintiff’s claimed injury and mechanism.

## Conclusion

In *Marsh v. Celebrity Cruises, Inc.*, the Southern District of Florida denied the cruise line’s motion to exclude a neuroradiologist’s DTI-based opinions, holding that the plaintiff made a sufficient Rule 702/*Daubert* showing that DTI evidence and Dr. York’s resulting mild-TBI opinions were reliable enough for jury consideration and that the defendant’s challenges were best addressed through cross-examination and contrary evidence.


Marsh v. Celebrity Cruises, Inc., 2017 WL 6987718 (2017)