Mohammed T. Abou-Saleh

ANATOMY OF THE AGING BRAIN 33Table 7.2continuedStudy Subjects Imaging and measurement technique FindingsGunning-Dixon etal., 1998 70 Same as Raz et al., 1997 MR imaging (1.5 tesla). Blinded volumemeasurements (digital planimetry) fromscans of T 1 -weighted reformatted coronalimages (1.3 mm thick, contiguous). Goodrater reliabilities among eight ratersGur et al., 1998 7117 Healthy volunteers (overlap withsubjects in Gur et al., 1991 andCowell et al., 1994) 31.9+8.9 yearsold, 13 M, 4 FGuttmann et al.,1998 72 72 Healthy volunteers, 18–81 years old,22 M, 50 F. No history of psychiatricillness, epilepsy, or severe head trauma.Handedness not specifiedJack et al., 1998 73Laakso et al., 1998 7424 Elderly volunteers, 70–89 years old(81.04+3.78 years), 8 M, 16 F. Noactive neurologic or psychiatric illness.Handedness not specified42 cognitively normal healthy elderlycommunity volunteers, 64–79 (72+4)years old, 19 M, 23 FMueller et al., 1998 75 46 Healthy elderly volunteers 65–74years old (6 M, 5 F), 75–84 years old(8 M, 7 F) and 85–95 years old (9 M,11 F). All functionally independent,MMSE524, and free of major medicaland neurologic illness, as well asdepression. Handedness not specifiedOguro et al., 1998 76152 Healthy adults, 81 M, 71 F, agerange 40s–70s. No evidence of neurologicaldiseasePfefferbaum et al.,1998 77 28 Healthy male volunteers (overlapwith Pfefferbaum et al., 1994), 21–68years old (51+13.8 years). No majormedical, neurologic, or psychiatric illness.Left-handers included (n not specified)Raz et al., 1998 78146 Healthy volunteers (overlap withRaz et al., 1997), 18–77 years old, 64 M(48+18 years); 82 F (46+17 years). Noevidence of major medical, neurologic orpsychiatric illness. All right-handedMR imaging (1.5 tesla). Volumemeasurements using a combination ofcomputer-assisted trace methodology andpixel segmentation of 3D images reconstructedfrom T 2 -weighted axial images(5 mm thick, contiguous). Good raterreliabilities, but ‘blindness’ not specified.Scanning repeated an average of 32months later.MR imaging (1.5 tesla). Blinded volumemeasurements using computer-assistedsegmentation and trace methodology ofcontiguous axial images (3 mm thick).Good interrater reliabilitiesMR imaging (1.5 tesla). Blinded volumemeasurements using computer-assistedtrace methodology of T 1 -weighted 3Dvolumetric images (1.6 mm thick, contiguous,n=124) by single rater withestablished reliabilitiesMR imaging (1.5 tesla). Volume measuresusing computer-assisted trace methodsfrom T 1 -weighted coronal images( 2 mm thick, contiguous) by a singleblinded rater with established reliabilitiesMR imaging (1.5 tesla). Volume measurements(non-blind?) using computerassistedpixel segmentation of contiguouscoronal images (4 mm thick). Excellentinterrater reliabilities. Scanning repeatedannually or biannually over 3–9 yearfollow-upMR imaging (0.2 tesla). Linear and areameasurements using computer-assistedtrace methodology from T 1 -weightedmidsagittal image (7 mm thick) andT 2 -weighted axial images (no details),by raters (n=?) with establishedreliabilitiesMR imaging (1.5 tesla). Blinded volumemeasurements derived from semiautomatedpixel segmentation of intermediateand T 2 -weighted axial images(n=17–20, 5 mm thick, 2.5 mm interscangap). Scanning repeated at 5 year followupMR imaging (1.5 tesla). Blinded volumemeasurements (digital planimetry) fromscans of T 1 -weighted reformatted coronaland sagittal images (0.8 mm thick, 1.5mm thick). Good rater reliabilitiesAge associated with decreased caudatevolume (L>R in males, R>L infemales), decreased putamen volume(R>L, males=females), and decreasedglobus pallidus volume (males only)No significant change over follow-up periodin whole brain, CSF or frontal lobevolumes. Significant volume loss wasobserved for L (7.5%) and R (7.2%)temporal lobesAge associated with decreased ratio of totalwhite matter volume to IV and decreasedtotal gray matter volume to IV. Interactionswith sex or laterality not reportedOver a 12 month interval, mean hippocampalvolume decreased by 1.55% andmean temporal horn volume increased by6.15% (males=females, L=R)No relation between age and hippocampalatrophyAdjusting for IV, age associated withdecreased volumes of total brain, hemispheres,frontal lobes, temporal lobes,basilar–subcortical region, hippocampus,and hippocampal gyrus. Interactionswith sex not reported. Over the follow-upperiod, significant volume decreases wereseen in hippocampus ( 0.02 ml/year),parahippocampal gyrus (in youngestgroup only, 0.05 ml/year), parietal–occipital region (in middle and oldest agegroups, 3 ml/year), and basilar region(in middle group only, 0.5 ml/year). Novolume decreases were seen in hemispheres,frontal lobes or temporal lobesAge associated with decreased linear measuresof midbrain tegmentum (males only),midbrain pretectum (males and females),and base of pons (males only), but notwith pontine tegmentum or fourth ventricle.Age associated with decreased areaof cerebellar vermis (males only), but notof pons. Age associated with decreasedratio of cerebrum to IA (males andfemales) at level of third ventricle and atlevel of body of lateral ventricles. Interactionswith laterality not reportedOver the follow-up interval, significantdecrease in total gray matter volume andin regional gray matter volume (pre-frontalgray 2 ml, or 7%; posterior parietooccipitalgray 1 ml, or 3.5%) (no changein frontal, anterior superior temporal,posterior superior temporal, or anteriorparietal regions gray matter volume). Interactionswith laterality not reportedAge associated with volume loss in cerebellarhemispheres ( 2%/decade), vermis,vermian lobules VI and VII ( 4%/decade), and posterior vermis (lobulesVIII-X; 2%/decade), but not in anteriorvermis (lobules I–V) or pons