Open AccessImproved 3D correction for partial volume effects in brain SPECT
Author(s) -
Itti Laurent,
Chang Linda,
Ernst Thomas,
Mishkin Fred
Publication year - 1997
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/(sici)1097-0193(1997)5:5<379::aid-hbm6>3.0.co;2-0
Subject(s) - partial volume , nuclear medicine , imaging phantom , biomedical engineering , artificial intelligence , computer science , medicine
An improved method for correction of partial volume effects (PVE) in brain SPECT is proposed. It is fully three‐dimensional, does not require particular patient positioning, and works with scans only partially covering the brain. The location of functionally inactive brain regions (primarily cerebrospinal fluid) is extracted from high‐resolution MRI. An automatic 3D registration algorithm then determines the geometric transformation between MRI and SPECT. Correction consists of: 1) counting the volumetric active/inactive ratio in each volume element of the functional scan using the measured SPECT point spread function; 2) correcting the functional measures according to these ratios; 3) fusing functional and anatomical information at the resolution of MRI. Quantitative validation was performed using a phantom containing a test region in which multiple parallel acrylic plates thinner than SPECT resolution created high PVE, as well as a large reference region not suffering from PVE. Reference activity was recovered in the test region with an accuracy of 1–3%. The method was applied to clinical images demonstrating a combination of hypoperfusion and cortical atrophy. The composite anatomical‐functional corrected images, in which the main sulci are visible, yield better differentiation between decreased function and focal atrophy. Hum. Brain Mapping 5:379–388, 1997. © 1997 Wiley‐Liss, Inc.