The MRN Mobile Imaging system is a custom designed one-of-a-kind facility. The heart of the mobile system is a Siemens’ 1.5T Avanto MRI. The Avanto is the most advanced 1.5T system in the Siemens product line.

The Avanto is a ultrashort 150cm (4’11’’) long, whole body superconductive 1.5T magnet with 5th generation active shielding (AS) technology with counter coils, External Interference Shielding (E.I.S.) and excellent homogeneity (based on 24 plane plot, 50 cm DSV type. 0.8 ppm). The system comes equipped with a 12-element Matrix head coil capable of ultra-fast parallel acquisition in either 4-channel (CP Mode), 8-channel (Dual Mode) or 12-channel (Triple Mode) settings. The SQ-engine gradients are the most advanced product on the Siemens’ platform. The SQ-engine gradients have a maximum amplitude of 45 mT/m for the longitudinal direction and 40 mT/m for horizontal and vertical direction. The gradient slew rate is 200 T/m/s with a minimal rise time of 200 µs (from 0-40 mT/m amplitude).

The Avanto is also equipped with AudioComfort - an acoustic noise buffer that leads to a 30dB attenuation of gradient noise compared to other conventional systems that leads to a reduction of 97% in sound pressure. This latter sound reduction is of great benefit to functional imaging studies. 

The MR system comes completely integrated into a trailer, which also houses a 72-channel Biosemi EEG/ERP data collection system for brain potential studies. The mobile trailer was built by Medical Coaches, Inc. http://www.medcoach.com/ . MIND Mobile Core Director, Dr. Kent Kiehl, custom designed the mobile coach to optimize the system for functional imaging.  A few of the modifications included a ventilated and shielded rear-projection box to the back wall of the trailer to house the high-resolution video projector for fMRI studies. The video image is projected thru a six inch waveguide and is redirected to the rear of the bore using a high resolution mirror. The projected image is displayed on a rear-projection screen at the back of the magnet bore. The participant views this image using a standard mirror system attached to the head coil. Three custom waveguides were installed between the control room and the magnet room for fiber-optic response devices, peripheral devices (skin conductance, heart rate) and passage of cables to the rear-projection box mounted on the back wall of the trailer. These, and other, modifications have enable the system to be optimized for collection of functional neuroimaging protocols. Example functional MRI data from the mobile MRI is provided in the Figures below. 

Results (left image) from the mobile MRI scanner of inmates (n=25) during commission of an error during a Go/No Go study (p < .001). Areas associated with error-monitoring include rostral and caudal anterior cingulate, thalamus, posterior cingulate, fusiform, and parietal cortex – repliciating results of prior studies (Kiehl et al., 2000). These data illustrate that the mobile MRI system is capable of collecting robust fMRI data. 

Results (right image) from the mobile MRI scanner of inmates (n=54) during target detection of an auditory ‘oddball’ task (p < .001). These data replicate previous results from our laboratory (Kiehl et al., 2005) and illustrate that the mobile imaging system is capable of collecting clean data in small, susceptibility-prone areas (i.e., right amygdala).

The mobile MRI system is also capable of collecting high resolution Diffusion Tensor Imaging (DTI). An example of the color coded DTI (FA) image collected from the mobile 1.5T scanner is shown at left. Colors are coded based on the direction of the fibers (red is left/right; green is superior/inferior; blue is anterior/posterior). 

Stability performance – one of the most critical developments of MRI technology in the last few years has been improvements in the temporal stability characteristics of MRI systems. The Siemens’ Avanto system was selected because our preliminary tests indicated that their systems provide very robust temporal stability – an essential component necessary for long time-series functional imaging data. The mobile MRI system has exceeded performance expectations in this regard – system specifications call for less than 1% peak-to-peak noise – average measurement has been less than 0.4% peak-to-peak – see figure below (based on the MGH stability sequence).

The MIND mobile imaging system was designed to serve to under-represented communities (e.g., rural areas) and/or special needs facilities. Specific projects include:

Increasing Understanding of the Mental Processes Underlying Substance Abuse, severe Impulsivity, and Antisocial/Psychopathic Behavior

The societal cost of crime in the United States is estimated to be $1.33 Trillion dollars a year (Anderson, 1999). That translates to nearly $4400 per year for every child, adolescent and adult in the United States. For the State of New Mexico our portion of that cost is estimated to be $8.87 billion dollars per year. And the cost of crime is growing. More than 200 new jail cells are built every day in the United States.  New Mexico’s incarcerated population (jails and prisons) has doubled in the last 10 years to over 10,000 inmates.

Much of crime is related to alcohol and substance abuse. The mobile imaging system is currently being used to assess the efficacy of how different treatments work to prevent relapses to methamphetamine, heroin and cocaine addiction and which treatments work best for different individuals.

Personality disorders, such as psychopathy, also have strong links to criminal behavior. Individuals with psychopathy have elevated risk for prison violations, parole violations, substance abuse, and general, violent, or sexually violent recidivism, in both males and females. The mobile MRI system is being used to study these conditions with the goal of translating the brain imaging findings into effective treatment protocols. 

For some individuals, behavioral problems begin at a very early age. The mobile MRI system is being used to study the environmental, cognitive, and behavioral characteristics of high-risk youth who are involved with the criminal justice system. The mobile MRI system will help delineate the developmental pathways that contribute to severe adolescent disruptive disorders.  By studying these pathways we will gain insight into the variables that lead to disruptive disorders. We can utilize this research to develop optimized treatment protocols tailored to the specific needs of each youth. 

BENEFITS TO STATE and SOCIETY AT LARGE
• Development of intervention strategies for the highest risk adolescents
• Improvement of alcohol and substance dependence treatment
• Over the long term, reduction of recidivism rates for juvenile and adult offenders

This one-of-a-kind mobile MRI unit is being driven from site to site and located inside the grounds of men’s and women’s correctional facilities and juvenile detention centers. Understanding the mental processes behind high-risk behaviors is the first step in providing better treatment for inmates in order to reduce recidivism rates and decrease the cost of criminal behavior to society.

For more information about the Mobile MRI Core/Clinical Neuroscience Laboratory and it's Director, Dr. Kent Kiehl