Mohammed T. Abou-Saleh

ANATOMY OF THE AGING BRAIN 29Table 7.2continuedStudy Subjects Imaging and measurement technique FindingsKrishnan et al.,1990 34 39 Healthy volunteers, 24–79 years old,17 M, 22 F. No evidence of majorMR imaging (1.5 tesla). Stereologicalmeasurement (one of two raters) ofmedical, neurologic, or psychiatric illness.Handedness not specifiedaxial slices (variable number, 5 mmthick, 2.5 mm interscan gap) fromintermediate and T 2 -weighted filmsDoraiswamy et al., 36 Healthy volunteers (overlap with1991 35 subjects Krishnan et al., 1990),26–79 years old, 16 M, 20 F. Noevidence of major medical, neurologic,or psychiatric illness. Handedness notspecifiedEscalona et al.,1991 36 37 Healthy volunteers (overlap withsubjects Krishnan et al., 1990), 24–79years old, 16 M, 21 F. No evidence ofmajor medical, neurologic, or psychiatricillness. Handedness not specifiedGur et al., 1991 3769 Healthy volunteers, 18–80 years old,34 M, 35 F. No neurologic or psychiatricillness; 66 right-handed; three left-handedMcDonald et al., 36 Healthy volunteers (subjects also includedin Krishnan et al., 1990), 24–791991 38 years old, 13 M, 23 F. No evidence ofmajor medical, neurologic or psychiatricillnessShah et al., 1991 3936 Healthy volunteers (overlap withsubjects in Krishnan et al., 1990),26–79 years old, 16 M, 20 F. No evidenceof major medical, neurologic, orpsychiatric illnessTanna et al., 1991 40 16 Healthy volunteers, 52–86 years old, 5M, 11 F. No evidence of major medical,neurologic, or psychiatric illness. Handednessnot specifiedCoffey et al., 1992 4176 Healthy volunteers, 36–91 years old,25 M, 51 F. No lifetime history ofneurologic or psychiatric illness. Allright-handedDoraiswamy et al., 75 Healthy volunteers (overlap with1992 42 subjects in Krishnan et al., 1990),21–82 years old (52.5+18 years),34 M, 41 F. No neurologic orpsychiatric illnessJack et al., 1992 43 22 Healthy elderly volunteers, 76.3+11.3years old, 10 M, 12 F. No major medicalor neurologic illness; no depression.Handedness not specifiedLim et al., 1992 4414 Healthy male volunteers, eight young(21–25 years old) and six elderly (68–76years old). No evidence of significantmedical or psychiatric illness. Handednessnot specifiedMR imaging (1.5 tesla). Area measurementof T 1 -weighted midsagittal imageusing computer-assisted trace methodology.Rater reliabilities not reportedMR imaging (1.5 tesla). Stereologicalmeasurement (one of two raters) ofaxial slices (variable number, 5 mm thick,2.5 mm interscan gap) from intermediateand T 2 -weighted films. Good rater reliabilitiesMR imaging (1.5 tesla). Volumemeasurements (any two of four raters)derived from segmentation techniquebased on two-feature pixel classificationof multiple spin-echo axial images (5 mmthick, contiguous)MR imaging (1.5 tesla). Same asKrishnan et al., 1990 (above)MR imaging (1.5 tesla). Computerassistedmeasurements from T 1 -weightedmidsagittal films by single rater withestablished intra-rater reliabilitiesMR imaging (1.5 tesla). Volumemeasurements (one of two raters withestablished reliabilities) derived fromsegmentation techniques based ontwo-feature pixel classification ofmultiple spin-echo axial images(5 mm thick, 2.5 mm interscan gap)MR imaging (1.5 tesla). Volumemeasurements (one of three blindedraters with established reliabilities)using computer-assisted tracemethodology of T 1 -weighted coronalimages (n=30–35, 5 mm thick,contiguous). Blinded clinical ratings(five-point scale) of ‘cortical atrophy’(average score of two raters)MR imaging (1.5 tesla). Blinded stereologicalmeasurements of volume andlinear measurements of size of midbrainon T 2 -weighted axial films (no additionaldetails provided)Age negatively correlated with total caudatevolume (males=females). Caudate volumewas less in subjects older than 50years (n=22). No adjustments for cranialsizeAge negatively correlated with corpuscallosum area in males but not in femalesNo association between age and volume ofcerebellar hemispheresOlder (555 years) subjects (n=26) hadsmaller whole brain volumes thanyounger subjects (males=females)Age negatively correlated with totalputamen volume (males=females;left=right), but no adjustments forcranial sizeIncreasing age associated with decreasingmidbrain area (males>females?). No ageeffects on areas of pons, medulla, anteriorcerebellar vermis or 4th ventricleAge negatively correlated with ratio of totalbrain volume to total CSF plus totalbrain volume. Interactions with sex orlaterality not reportedAge associated with decreased total volumesof the cerebral hemispheres(0.23%/year), the frontal lobes (0.55%/year), the temporal lobes (0.28%/year),and the amygdala–hippocampal complex(0.30% per year); all effects similar formales and females, and for both hemispheres.Increasing age associated withincreasing odds (8.9%/year) of ‘corticalatrophy’, from 0.08 at age 40 to 2.82at age 80Age negatively correlated with midbrainvolume and anteroposterior diameter,but not with red nucleus size. Effectssimilar for both males and femalesMR imaging (1.5 tesla). Volume estimates Age associated with decreased ratio of(single rater) derived from computerassistedpixel classification of T 1 -weighted anterior temporal lobe volume to IV.hippocampal volume to IV and ofcoronal images (4 mm thick, contiguous). Interactions with sex or laterality notIntra-rater reliabilities not reported reportedMR imaging (1.5 tesla). Blindedvolume measurements derived fromsemi-automated pixel segmentationof intermediate and T 2 -weighted axialimages (n=8, 5 mm thick, 2.5 mminterscan gap)Compared to younger males, older maleshad lower ratio of gray matter volume toIV (49.7% vs. 38.7%). No group differencein ratio of white matter volume toIV (47.2% vs. 41.2%). Interactions withlaterality not reportedcontinues overleaf