Image manipulation and error estimation for MRI analysis.
Manipulation of MRI images prior to volumetric analysis is a common practice that may unwittingly lead to errors in measurement. In this study, we examine the effects of two types of image manipulation: changes in the total number of slices used to obtain volume estimates (slice sampling rate) and image rotation. A phantom containing two regularly-shaped and two irregularly-shaped regions of interest (ROIs) was scanned using an SPGR sequence and 1-mm slices. Changes in slice sampling rate produced marked effects on volume estimation of irregularly-shaped ROls. Comparatively little error was associated with changes in slice sampling rates for regularly-shaped ROIs. In addition, there was an interaction between image rotation in non-orthogonal planes and slice sampling rate. The data suggests that the ability to detect anatomical effects may be influenced by an investigator's choices concerning the number of slices included in a region of interest and image rotation when estimating volumes.
Plante
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The National Center for Neurogenic Communication Disorders, The University of Arizona, Tucson 85721-0071, USA.
Uecker
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Senkfor
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Gmitro
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AF
D005069:Evaluation Studies as Topic; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards*; D009488:Neurosciences / Q000379:methods*; D019047:Phantoms, Imaging; D012399:Rotation