SPECT Scans: Ontario Courts Grapple with a “Novel” Evidentiary Tool

  • February 10, 2023
  • Grace Murdoch


In recent years, single-photon emission computerized tomography scans (otherwise known as “SPECT” scans) have been the subject of debate in Ontario’s court rooms when evaluating brain injury claims.

Whether the conclusions resulting from such scans can be admitted into evidence and for what purpose are increasingly becoming important questions in personal injury law.

What is a SPECT Scan?

SPECT scans are a form of nuclear imaging testing which use computed technology and a radioactive tracer to produce 3D images that show the blood flow activity in organs and give insight into their functioning. This is in contrast to imaging such as CAT scans or MRIs, which produce an image of the internal body.

SPECT scans have been in use for approximately 30 years and have been used for a variety of purposes related to brain disorders (e.g. clogged blood vessels, seizure disorders, or  Parkinson’s disease), heart problems (e.g. clogged coronary arteries or reduced pumping efficiency), and bone disorders.[1] Where the controversy lies in the legal field is whether a SPECT scan can accurately assist in the diagnosis of a traumatic brain injury (“TBI”) even where other forms of medical imaging indicate otherwise.

Two recent decisions from the Ontario Superior Court of Justice have considered the admissibility of SPECT scans, and of what use, if any, it provides in a legal analysis of TBIs.

Meade v. Hussein, 2021 ONSC 7850

In Meade v Hussein[2], the plaintiff claimed to have suffered a TBI in a motor vehicle accident as well as psychological and emotional trauma. She underwent a SPECT brain scan, which the plaintiff’s expert concluded represented a TBI. The defendant in this action moved for the SPECT-related evidence to be excluded on the basis that it being used to diagnose a TBI is considered “novel science” which does not meet the requisite reliability criteria to properly be used by the court as evidence.

The first issue that Justice Bale  considered was whether brain SPECT evidence constitutes a novel science.  Although SPECT imaging itself is not a “novel” concept, it was determined that its use to diagnose TBIs was.

Justice Bale then considered whether this novel purpose met the “reliable foundation test” as set out in R. v. J.-L.J.[3] to determine whether it was sufficiently reliable nevertheless. This test involved the assessment of four factors:

(1) whether the theory or technique can be and has been tested;

(2) whether the theory or technique has been subject to peer review and publication;

(3) whether there is a known or potential rate of error or the existence of standards to test the theory or technique; and,

(4) whether the theory or technique is generally accepted by the relevant scientific community.

In summary, the plaintiff’s expert conceded that his methodology had not been tested and conceded that that his work had not been published or peer-reviewed nor were there are any peer-reviewed articles supporting his theory that brain SPECT imaging can be used to distinguish TBIs from depression or anxiety disorders. It was further determined that there was no known or potential rate of error associated with the expert’s theory or technique nor was there sufficient evidence that the theory or technique has been generally accepted by the relevant scientific community.

Given that the reliability is not confined only to the four factors listed in R. v. J.-L.J, Justice Bale also heard evidence as to the plaintiff’s expert’s experience in administrating SPECT scans, his own explanation of his theory, and examples of cases in which SPECT evidence has been admitted. None of these factors, however, elevated the reliability of the SPECT usage in this case to meet the basic level of reliability required for expert evidence.

Wabie v. Wilson, 2022 ONSC 4296

Although the Meade decision signalled that brain SPECT evidence would be inadmissible as a tool to diagnose TBIs, the decision of Wabie v Wilson[4] rendered shortly after, revisited this topic and considered whether SPECT evidence could be used in a different capacity.

Like Meade, the plaintiff in Wabie claimed to have suffered a TBI in a motor vehicle collision. Unlike Meade, an objection to SPECT evidence was raised only after it had formed part of the evidentiary record.

In Waibe, the plaintiff reported symptoms to her doctor following the accident who made a post-concussion syndrome diagnosis. He then referred the plaintiff to a concussion clinic where she underwent an MRI which indicated that she did not have a TBI. She was later referred to take a SPECT scan which resulted in the opposite conclusion.

The defendant raised the Meade decision in support of setting aside the SPECT evidence. Justice Sutherland, however, did not regard SPECT scans as a novel science, citing its temporal and geographic history of usage as a diagnostic tool and finding support in other court decisions which admitted such forms of evidence. The court noted that Meade was distinguishable in the sense that in Meade, the SPECT evidence was used as a diagnostic tool for a TBI whereas in the case at bar, the SPECT imaging was conducted after a doctor had made a diagnosis and was used for the purpose of supporting the diagnosis and other complaints. As such, Justice Sutherland concluded that SPECT scans can be used as a secondary tool, and not as a primary tool, for a TBI diagnosis and in this circumstance, the SPECT evidence was properly admissible.

Also in Meade, there was an issue as to SPECT scans being a tool to differentiate a TBI from anxiety and depression. Because this was not an issue in Waibe, Sutherland J further distinguished it on that basis.  


The key takeaways of these decisions can be summarized as follows:

  • The decisions in Waibe and Meade demonstrate that Ontario courts have taken different approaches to categorizing SPECT scans and reached different conclusions as to whether their use is a “novel science”. The distinction seems to turn on the purpose for which the SPECT scan evidence is used.
  • While Waibe demonstrates that there may be increased acceptance of SPECT scan evidence in future actions, it appears that it only opens the door for SPECT scans to be used as a secondary tool to support a diagnosis and not a primary diagnostic tool.

Both cases are examples of the legal system’s attempt to grapple with evolving medical technology in order to better understand the impact of injury the human body’s most complex and important organ. Waibe represents a notable shift from Meade and indicates that SPECT scan evidence is potentially admissible. It remains to be seen whether future courts will add further clarification or commentary on this issue.


[1] “SPECT scan” (July 2022), online: Mayo Clinic < https://www.mayoclinic.org/tests-procedures/spect-scan/about/pac-20384925>

[4] 2022 ONSC 4296.

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