title: The impact of variation in the pulse sequence parameters on image uniformity in magnetic resonance imaging.
abstract: OBJECTIVE
  To evaluate the practical impact of alteration of key imaging parameters of Magnetic Resonance Imaging on image quality and effectiveness provided by widely available fast imaging pulse sequences.
  
  
  METHODS
  A tissue equivalent material for Magnetic resonance Imaging (MRI) has been produced from a polysaccharide gel, agros, containing gadolinium chloride chelated to Ethylene Diamine Tetra- Acetic acid (EDTA) with a sort of T1 and T2 values. Experimental variations in key parameters included echo time (TE) and repetition time TR. Quantitative analysis consisted of image nonuniformity.
  
  
  RESULTS
  In T2 weighted images; any change in TE played a critical role in the signal homogeneity in all pulse sequences. The percentage of nonuniformity was incredibly high in T2 weighted image but the change of TR was insignificant in T2-weighted study. Involving T1 weighted images, percentage of nonuniformity was high in gradient recalled echo (GRE), also noticeable in fast fluid attenuated recovery (FLAIR) but quite acceptable in fast spin echo (FSE) and conventional spin echo (CSE).
  
  
  CONCLUSIONS
  Selection of parameters relatively simple in CSE both in T1, T2-weighted study that maintains image uniformity and quality as well. GRE is a very sensitive pulse sequence for any variation in parameters and loose signal uniformity rapidly.
authors.affiliation: Department of Physics, The Islamia University of Bahawalpur, Pakistan.
authors.forename: Naima
authors.initials: N
authors.lastname: Amin
authors.forename: Mohammad
authors.initials: M
authors.lastname: Afzal
mesh_terms: D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results