fMRI Technique

** Presentation of fMRI technique by scientific expert witness Chris DiFiore for the trial of defendant Jimmy Moran.

Ladies and gentlemen of the juror, in order to understand the power and limitations of fMRI, you must first apprehend the basic principles of magnetic resonance imaging (MRI). The use of MRI has become a standard piece of equipment for Radiology by providing high-resolution images that demonstrates contrast between different types of tissues. It has the ability to diagnosis problems such as tumors, bleeding, tissue damage, and can provide additional information from other commonly used scans such as CT scans and X-Ray’s.

In regards to its mechanism of operation, the physical aspect is fairly complex. The MRI scanner contains an electro-magnet that is capable of producing a magnetic field over 50,000 times that of Earth’s (1). When normal internal randomly oriented hydrogen nuclei are exposed to this field, they are forced to align with the field’s direction. As the nuclei are lined up, a magnetic radio frequency pulse is applied. At the right frequency, these small hydrogen nuclei absorb energy and produce a faint signal that is large enough to measure. The resultant image is the distribution of this faint signal that is altered by the timing of the radio frequency pulses. This allows a structural brain image to be formed. (2)

Furthermore, it is important to not confuse the type of image a basic MRI produces. The MRI produces a structural image that reveals the anatomy of a subject’s brain. What we are interested in is the functionality and areas of activity of the brain; this is the job of the functional magnetic resonance imaging (fMRI) machine. The fMRI is a relatively newly developed technique that uses b...

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...itness is lying, if a witness was at the crime scene, if the defendant feels remorse, or any other courtroom associated question. The possibilities could be endless as the advancement of this technology develops.

Works Cited

Devlin, Hannah. "What Is Functional Magnetic Resonance Imaging (fMRI)? | Psych Central." Psych Central.com. PsychCentral, 30 Jan. 2013. Web. 06 Dec. 2013.

(2) Shin, David, Dr. "What Is FMRI?" What Is FMRI? UC San Diego School of Medicine, n.d. Web. 06 Dec. 2013.

(3) Miller KL, Hargreaves BA, Lee J, Ress D, de Charms CR, Pauly JM. Functional brain imaging using a blood oxygenation sensitive steady state. Magn Reson Med.2003;50:675–683.

(4) Lindquist M The statistical analysis of fMRI data. Stat Sci 23: 439–464,2008.

(5) Miller, Greg. "FMRI Evidence Used in Murder Sentencing." Science/AAAS. Science Insider, 23 Nov. 2009. Web. 06 Dec. 2013.