Reading the Image, and the Limits of the Image
A short read on what imaging shows, what it does not prove, and where attorney-side over-reading tends to happen.
A 47-year-old man with well-controlled hypertension is in a rear-end motor vehicle collision and reports post-collision headache, sleep disturbance, and difficulty concentrating. A brain MRI obtained six weeks later shows a handful of small white matter hyperintensities (WMH, small bright spots on a particular MRI sequence, common in the general adult population and accumulating with age and with vascular risk factors such as hypertension and diabetes). The plaintiff's expert attributes the findings to the collision. The defense expert attributes them to age. Neither report addresses whether a pre-collision baseline scan exists. Neither engages the literature on WMH prevalence in age-matched controls. Both opinions ask one MRI to carry more than one MRI can carry.
Imaging documents pathology that exists, excludes certain pathology that does not, and produces an exhibit a jury can see. What it does not do is establish causation by being abnormal, date an injury to a clock-precision moment, or measure function. The question this issue takes seriously is what an imaging-heavy case actually examines, once the over-reading on either side is set aside.
A defensible review rests on a small set of specific questions, most of them about the modality and the timing rather than the pixels. Was the modality appropriate to the claimed injury, CT (computed tomography, an X-ray-based brain image, fast and sensitive to acute hemorrhage and skull fracture) for acute bleeding and bone, MRI (magnetic resonance imaging, longer to acquire, more sensitive to subtle brain injury) for subtle parenchymal or posterior-fossa pathology? When was the scan obtained relative to the incident, and does the timing match what the imaging is being read to show? A finding labeled "acute" in a study obtained three weeks after the alleged event warrants a second look. Is there pre-incident imaging available for comparison, and if not, does the analysis honor that absence rather than paper over it? Are the findings specific to the alleged mechanism, or compatible with age, vascular risk factors, prior injury, or chronic disease? Do the findings correlate with the documented neurological examination, do the patient's deficits fall in the territory the imaging finding marks? Is advanced imaging, diffusion tensor imaging (DTI, a research MRI technique that maps water movement along white-matter tracts), functional MRI, or volumetric analysis being offered at the level the literature currently supports, or beyond it?
The Primer in this month's Writings walks through CT and MRI, their specialized sequences, the misinterpretation patterns that recur in litigation, and the difference between what a radiologist's report says and what a clinician's opinion can carry. The point worth carrying into a file review is structural. An image is evidence of what it shows. It is not, by itself, evidence of what caused it. In an imaging-heavy case, the work is deciding what the image means in this specific patient, against this specific timeline, with this specific comparator. On either side, the opinions that overshoot are the ones that asked the imaging to settle a question only the analysis can settle.
Tobias B. Kulik, MD, FAAN, CIME/ABIME, CPPS
CorteXion LLC · Scientia et Veritas
The Primer in this month's Writings
Neuroimaging in Litigation: What It Shows, What It Does Not Prove — cortexion.co/writings/neuroimaging-in-litigation
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