PMID- 31922311
OWN - NLM
STAT- MEDLINE
DCOM- 20210510
LR  - 20210601
IS  - 1522-2586 (Electronic)
IS  - 1053-1807 (Print)
IS  - 1053-1807 (Linking)
VI  - 52
IP  - 1
DP  - 2020 Jul
TI  - Evaluation of a Workflow to Define Low Specific Absorption Rate MRI Protocols for 
      Patients With Active Implantable Medical Devices.
PG  - 91-102
LID - 10.1002/jmri.27044 [doi]
AB  - BACKGROUND: MRI exams for patients with MR-conditional active implantable medical 
      devices (AIMDs) are contraindicated unless specific conditions are met. This 
      limits the maximum specific absorption rate (SAR, W/kg). Currently, there is no 
      general framework to guide meeting a lower SAR limit. PURPOSE: To design and 
      evaluate a workflow for modifying MRI protocols to whole-body SAR (WB-SAR 
      </=0.1 W/kg) and local-head SAR (LH-SAR </=0.3 W/kg) limits while mitigating the 
      impact on image quality and exam time. STUDY TYPE: Prospective. POPULATION: 
      Twenty healthy volunteers on head (n = 5), C-spine (n = 5), T-spine (n = 5), and 
      L-spine (n = 5) with IRB consent. ASSESSMENT: Vendor-provided head, C-spine, 
      T-spine, and L-spine protocols (SAR(RT) ) were modified to meet both low SAR 
      targets (SAR(LOW) ) using the proposed workflow. in vitro SNR and CNR were 
      evaluated with a T(1) -T(2) phantom. in vivo image quality and clinical 
      acceptability were scored using a 5-point Likert scale for two blinded readers. 
      FIELD STRENGTH/SEQUENCES: 1.5T/spin-echoes, gradient-echoes. STATISTICAL 
      ANALYSIS: In vitro SNR and CNR values were evaluated with a repeated measures 
      general linear model. in vivo image quality and clinical acceptability were 
      evaluated using a generalized estimating equation analysis (GEE). The two 
      reader's level of agreement was analyzed using Cohen's kappa statistical 
      analysis. RESULTS: Using the workflow, SAR limits were met. LH-SAR: 
      0.12 +/- 0.02 W/kg, median (SD) values for LH-SAR were 0.12 (0.02) W/kg and WB-SAR: 
      0.09 (0.01) W/kg. Examination time did not increase </=2x the initial time. SAR(RT) 
      SNR values were higher and significantly different than SAR(LOW) (P < 0.05). 
      However, no significant difference was observed between the CNR values (value = 
      0.21). Median (IQR) CNR values were 14.2 (25.0) vs. 15.1 (9.2) for head, 12.1 
      (16.9) vs. 25.3 (14.2) for C-spine, 81.6 (70.1) vs. 71.0 (26.6) for T-spine, and 
      51.4 (52.6) vs. 37.7 (27.3) for L-spine. Image quality scores were not 
      significantly different between SAR(RT) and SAR(LOW) (median [SD] scores were 4.0 
      [0.01] vs. 4.3 [0.2], P > 0.05). DATA CONCLUSION: The proposed workflow provides 
      guidance for modifying routine MRI exams to achieve low SAR limits. This can 
      benefit patients referred for an MRI exam with low SAR MR-conditional AIMDs. 
      LEVEL OF EVIDENCE: 1 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 
      2020;52:91-102.
CI  - (c) 2020 International Society for Magnetic Resonance in Medicine.
FAU - Martinez, Jessica A
AU  - Martinez JA
AUID- ORCID: 0000-0002-3274-566X
AD  - Department of Bioengineering, University of California, Los Angeles, California, 
      USA.
AD  - Department of Radiological Sciences, University of California, Los Angeles, 
      California, USA.
FAU - Moulin, Kevin
AU  - Moulin K
AD  - Department of Radiology, Stanford University, Stanford, California, USA.
FAU - Yoo, Bryan
AU  - Yoo B
AD  - Department of Radiological Sciences, University of California, Los Angeles, 
      California, USA.
FAU - Shi, Yu
AU  - Shi Y
AD  - Department of Radiological Sciences, University of California, Los Angeles, 
      California, USA.
FAU - Kim, Hyun J
AU  - Kim HJ
AD  - Department of Radiological Sciences, University of California, Los Angeles, 
      California, USA.
FAU - Villablanca, Pablo J
AU  - Villablanca PJ
AD  - Department of Radiological Sciences, University of California, Los Angeles, 
      California, USA.
FAU - Ennis, Daniel B
AU  - Ennis DB
AD  - Department of Radiology, Stanford University, Stanford, California, USA.
LA  - eng
GR  - R21 HL127433/HL/NHLBI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20200110
PL  - United States
TA  - J Magn Reson Imaging
JT  - Journal of magnetic resonance imaging : JMRI
JID - 9105850
SB  - IM
MH  - Humans
MH  - *Magnetic Resonance Imaging
MH  - Phantoms, Imaging
MH  - Prospective Studies
MH  - *Prostheses and Implants
MH  - Workflow
PMC - PMC8166235
MID - NIHMS1700295
OTO - NOTNLM
OT  - MR-conditional
OT  - MR-safety
OT  - MRI
OT  - SAR
OT  - active implantable medical devices
OT  - low SAR
EDAT- 2020/01/11 06:00
MHDA- 2021/05/11 06:00
PMCR- 2021/05/31
CRDT- 2020/01/11 06:00
PHST- 2019/09/30 00:00 [received]
PHST- 2019/12/16 00:00 [revised]
PHST- 2019/12/18 00:00 [accepted]
PHST- 2020/01/11 06:00 [pubmed]
PHST- 2021/05/11 06:00 [medline]
PHST- 2020/01/11 06:00 [entrez]
PHST- 2021/05/31 00:00 [pmc-release]
AID - 10.1002/jmri.27044 [doi]
PST - ppublish
SO  - J Magn Reson Imaging. 2020 Jul;52(1):91-102. doi: 10.1002/jmri.27044. Epub 2020 
      Jan 10.