Minutes from 9/12 MGH-BWH mini-BIRN telecon

MGH-BWH Calibration Team teleconference minutes 9/12/05

Attendees:

Nan-kuei Chen Brad Dickerson Randy Lyanne Gollub Doug Greve Jorge Jovicich Ron Kikinis Andrew Kiruluta Steve Pieper Reisa Sperling Kelly Su Sandy Wells Cindy Wible Chris Wright

Minutes

• 1. Brad: Purpose of telecon & Introductions
  • Goal: Establishment of standard intra-site calibration procedures
    • Can we use this opportunity (BWH & MGH upgrade) to standardize as much of the procedure as possible such that both sites collect comparable data and perform similar analyses?
• 2. Current daily calibration procedures
  • Randy: What are the daily QA measures employed on clinical scanners at MGH?
  • Andrew: standard nema daily calibration
    • Uniform phantom SNR (ROI inside phantom of interest is signal; outside is noise);

Geometric distortion (EPI, struct) (ACRadiol standard)

• ** Doug: this is similar to MGH CNY daily QA measures: cylindrical phantom 200 tps, draw roi @ center of phantom, measure peak to peak change divided by avg intensity inside of phantom (a la SNR measure)
  • Doug: CNY has developed a method to analyze nyquist ghosting to see if there is a change over time: segment phantom from background & use mask (ghost roi)
  • Steve: BWH research scanners use fbirn protocol
• 3. Brief overview of basic calibration plans at each site (intra-site)
  • MGH (Jorge)--see notes below
    • Doug: We also want to examine baseline noise pre & post upgrade & try to separate noise components (different flip angles); field angle map & T2* & B0 map
    • Jorge: Plans are for 2 phantom sessions each pre & post upgrade
    • Jorge: Plans are for 4 subjects each 2 scans pre & post upgrade
  • BWH (Nan-kuei)
    • 1.5t mainly clinical research; acr phantom standard
    • 3t haven’t used acr in past
    • Reisa: we need to consider mprage; also need to consider the fact that adni protocols will be used on 1.5t bwh, 3t bwh, 3t trio mgh
    • Ron/Brad: We would like to agree to use the same sequence for a given purpose, as long as there is not a compelling reason to do otherwise (i.e., try to avoid two different versions of MPRAGE so as not to have to compare intra-site inter-sequence)
    • Steve: We need to obtain GE mprage sequence for new platform
    • Reisa: This was created for adni on GE & it’ll be at bwh after upgrade
    • Reisa/Jorge/Brad/Chris: We should make sure to calibrate across coils (single vs 8 vs 12 channel)
    • Doug/Nan-kuei: would like to ensure that details of sequences are very similar on ge & siemens (k space trajectory; ghosting, etc)
    • Ron: Regardless of the fact that relatively heavier investments have been made in cross-site calibration, we should have a standard plan in place to characterize the systematic error within a scanner, including the effects of an upgrade.
  • Human plans at bwh
    • Rescan subjects who have been scanned as part of fbirn phase 2 & mem fmri
  • Jorge: How many subjects is enough for adequate calibration?
  • Reisa: plan is for 20 for cross-site
  • Jorge: probably depends on question of interest & inherent noise (~5 for upgrades – 20+ for cross-site)
• IRB issues
  • Jorge: It would be ideal for all of us to estimate how many scans we are likely to perform per year so we can put irbs in place & allot technical resources.
  • Randy/Brad: It would be ideal to have one IRB for both sites’ calibration efforts, but it would be essential to ensure detailed record-keeping, given that a number of co-investigators would likely use it.
• Randy: We need to continue to ask for Kelly & Sandy’s attention to statistical analysis approaches (e.g., from the simpler daily nema-type tests to the most detailed freesurfer-based morphometric or intensity-based comparisons (X Han’s & S Czanner’s methods @ CNY)

• Items to consider for next telecon agenda
  • Discussion of other 'wish-list' items for intra-site calibration
    • Other sequences (DTI, ASL variants)
    • Resources for data analysis
  • Goal: Team calibration resources
    • How can we coordinate resources to maintain an MGH-BWH calibration team?
      • Team membership: what other skills do we need?
      • Document management system
      • Resources for scanning, data archiving and analysis
        • Personnel
        • Computer

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