T2* Measurement bias due to concomitant gradient fields.
Magn Reson Med
; 77(4): 1562-1572, 2017 04.
Article
en En
| MEDLINE
| ID: mdl-27186845
ABSTRACT
PURPOSE:
To demonstrate that concomitant magnetic fields can cause significant spatially dependent biases in T2* relaxometry measurements with implications for clinical applications such as BOLD and dynamic susceptibility contrast-enhanced MRI. THEORY ANDMETHODS:
After developing a theoretical framework for intravoxel dephasing and signal loss from concomitant magnetic fields, this framework and the effect of concomitant fields on T2* are validated with phantom experiments and numerical simulation. In lower leg and renal T2* mapping, we quantify measurement bias for imaging protocols with high gradient amplitude multiecho readouts, comparable to those used in clinical applications.RESULTS:
Concordance between phantom experiment and numerical simulation validate the theoretical framework. Changes in T2* measured in the lower leg and kidney varied by up to 15% and 35%, respectively, as a result of concomitant gradient effects when compared with the control measurements.CONCLUSION:
Concomitant magnetic fields produced by imaging gradient coils can cause clinically significant T2* mapping errors when high amplitude, long duration gradient waveforms are used. While we have shown that measurement biases can be quite large, modification of imaging parameters can potentially reduce concomitant field-induced measurement errors to acceptable levels. Magn Reson Med 771562-1572, 2017. © 2016 International Society for Magnetic Resonance in Medicine.Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Imagen por Resonancia Magnética
/
Interpretación de Imagen Asistida por Computador
/
Artefactos
/
Músculo Esquelético
Tipo de estudio:
Diagnostic_studies
/
Guideline
Límite:
Female
/
Humans
Idioma:
En
Revista:
Magn Reson Med
Asunto de la revista:
DIAGNOSTICO POR IMAGEM
Año:
2017
Tipo del documento:
Article
País de afiliación:
Estados Unidos