Intracranial Volume Measurements Research Articles

Assessment of nurse practitioners’ capacity of using the ABC/2 formula for intracranial lesion volume measurement

BackgroundThis study investigates the precision of nurse practitioners (NPs) in measuring intracranial lesion volumes using the ABC/2 method, a simple yet widely used technique in neurosurgical practices. Amidst physician workforce shortages, the role of NPs in clinical practice, including specialized tasks like lesion volume estimation, is gaining importance.MethodsWe conducted a retrospective study involving patients treated for intracranial meningiomas. NPs estimated tumor volumes using the ABC/2 method, which was then compared with automated ABC/2 estimations considered as the gold standard. Statistical analyses, including paired sample t-tests, Bland-Altman analysis, and Intraclass Correlation Coefficient (ICC) analysis, were employed to assess measurement accuracy and consistency.ResultsAmong the 265 meningioma patients included, NPs measured the average tumor volume as 36.95 ml, generally underestimating it compared to the 39.57 ml average obtained by the automated ABC/2 method. This underestimation, however, was clinically modest, indicated by an average percentage difference of 6.59% and a Cohen’s d value of 0.08. Consistency in measurements, assessed using Bland-Altman and ICC analyses, demonstrated a high level of agreement between NPs measurements and the automated method. Additionally, no significant differences in measurement accuracy were observed either among different NPs or across NPs with varying levels of work experience.ConclusionsNurse practitioners can effectively employ the ABC/2 method for estimating intracranial lesion volumes with reasonable accuracy and consistency, irrespective of their work experience. This finding is pivotal in enhancing the role of NPs in neurosurgical practices and could be significant in alleviating the strain caused by the global shortage of physicians. Future research may explore extending NPs’ roles in other clinical diagnostic and therapeutic tasks.

Volumetric Assessment of Traumatic Intracranial Hematomas: Is ABC/2 Reliable?

Accurate measurement of traumatic intracranial hematoma volume is important for assessing disease progression and prognosis, as well as for serving as an important end-point in clinical trials aimed at preventing hematoma expansion. While the ABC/2 formula has traditionally been used for volume estimation in spontaneous intracerebral hemorrhage, its adaptation to traumatic hematomas lacks validation. This study aimed to compare the accuracy of ABC/2 with computer-assisted volumetric analysis (CAVA) in estimating the volumes of traumatic intracranial hematomas. We performed a dual-center observational study that included adult patients with moderate-to-severe traumatic brain injury. Volumes of intracerebral, subdural (SDHs), and epidural hematomas from admission computed tomography scans were measured using ABC/2 and CAVA, and compared using the Wilcoxon signed-rank test, Spearman's rank correlation, Lin's concordance correlation coefficient (CCC), and Bland-Altman plots. Prognostic significance for outcomes was evaluated through logistic and linear regression models. In total, 1,179 patients with 1,543 hematomas were included. Despite a high correlation (Spearman coefficients between 0.95 and 0.98) and excellent concordance (Lin's CCC from 0.89 to 0.96) between ABC/2 and CAVA, ABC/2 overestimated hematoma volumes compared with CAVA, in some instances exceeding 50 ml. Bland-Altman analysis highlighted wide limits of agreement, especially in SDH. While both methods demonstrated comparable accuracy in predicting outcomes, CAVA was slightly better at predicting craniotomies and midline shift. We conclude that while ABC/2 provides a generally reliable volumetric assessment suitable for descriptive purposes and as baseline variables in studies, CAVA should be the gold standard in clinical situations and studies requiring more precise volume estimations, such as those using hematoma expansion as an outcome.

Improving Access to Intracranial Volume Measurements for Clinical Use: Open-Source Method using Computed Tomography

Introduction: Three-dimensional measurements of intracranial volume (ICV) can guide clinical management of brain and skull disorders. However, widespread clinical access is limited by the scarcity of software methods for analyzing CT scans, which are more available than MRI images, and the inaccessibility of proprietary and expensive commercial software. The presented method can calculate ICV from CT scans, using an open-source software, 3D Slicer. Methods: The open-source workflow was optimized with a data-driven approach to find the optimal parameters for ICV accuracy. The accuracy of the open-source method was determined by comparing it to commercial and proprietary software with CT scans of pediatric hydrocephalic macrocephaly patients with craniosynostosis undergoing total vault reconstruction (N = 5 patients,15 scans). Results: An open-source pipeline that combines an initial semi-automatic segmentation of a coronal CT reconstruction with a fully automatic segmentation minimizes the ICV error. The open-source method shows excellent agreement with both the commercial and proprietary software methods (R2 = 0.998 and 95% confidence interval of best-fit line slope: [0.986; 1.047], [0.985;1.066] respectively). The mean percent difference of ICV measurements of the open-source software from the commercial software was −0.56% [95% CI: −1.08%, −0.028%] and from the proprietary software was −0.07% [95% CI: −1.26%, 1.1%]. The mean percent difference of ICV measurements of the commercial software from the proprietary software was 0.36% [95% Confidence Interval: −0.61%, 1.32%]. Conclusions: This is the first study comparing an open-source method for measuring ICV with commercial and proprietary options. A high degree of fidelity was found, confirming this open-source method as a viable option for clinicians who are looking to incorporate ICV measurements into their practice.

Reliability of Automated Intracranial Volume Measurements by Synthetic Brain MRI in Children

Reliability of Automated Intracranial Volume Measurements by Synthetic Brain MRI in Children

Total intracranial hemorrhage volume measurement summating all compartments best in traumatic and nontraumatic intracranial bleeding.

The ANNEXA-4 trial measured hemostatic efficacy of andexanet alfa in patients with major bleeding taking factor Xa inhibitors. A proportion of this was traumatic and nontraumatic intracranial bleeding. Different measurements were applied in the trial including volumetrics to assess for intracranial bleeding depending on the compartment involved. We aimed to determine the most reliable way to measure intracranial hemorrhage (ICrH) volume by comparing individual brain compartment and total ICrH volume. Thirty patients were randomly selected from the ANNEXA-4 database to assess measurement of ICrH volume by compartment and in total. Total and compartmental hemorrhage volumes were measured by five readers using Quantomo software. Each reader measured baseline hemorrhage volumes twice separated by 1 week. Twenty-eight different ANNEXA-4 subjects were also randomly selected to assess intra-rater reliability of total ICrH volume measurement change at baseline and 12-h follow up, performed by three readers twice to assess hemostatic efficacy categories used in ANNEXA-4. Compartmental minimal detectable change percentages (MDC%) ranged between 9.72 and 224.13, with the greatest measurement error occurring in patients with a subdural hemorrhage. Total ICrH volume measurements had the lowest MDC%, which ranged between 6.57 and 33.52 depending on the reader. Measurement of total ICrH volumes is more accurate than volume by compartment with less measurement error. Determination of hemostatic efficacy was consistent across readers, and within the same reader, as well as when compared to consensus read. Volumetric analysis of intracranial hemostatic efficacy is feasible and reliable when using total ICrH volumes.

Sex significantly predicts medial temporal volume when controlling for the influence of ApoE4 biomarker and demographic variables: A cross-ethnic comparison.

To explore the relationship between age, education, sex, and ApoE4 (+) status to brain volume among a cohort with amnestic mild cognitive impairment (aMCI). One hundred and twenty-three participants were stratified into Hispanic (n = 75) and White non-Hispanic (WNH, N = 48). Multiple linear regression analyses were conducted with age, education, sex, and ApoE4 status as predictor variables and left and right combined MRI volumes of the hippocampus, parahippocampus, and entorhinal cortex as dependent variables. Variations in head sizes were corrected by normalization with a total intracranial volume measurement. Bonferroni-corrected results indicated that when controlling for ApoE4 status, education, and age, sex was a significant predictor of hippocampal volume among the Hispanic group (β = .000464, R2 = .196, p < .01) and the WNH group (β = .000455, R2 = .195, p < .05). Education (β = .000028, R2 = .168, p < .01) and sex (β = .000261, R2 = .168, p < .01) were significant predictors of parahippocampal volume among the Hispanic MCI group when controlling for the effects of ApoE4 status and age. One-way ANCOVAs comparing hippocampal and parahippocampal volume between males and females within groups revealed that females had significantly larger hippocampal volumes (p < .05). Hispanic females had significantly larger hippocampal (p < .001) and parahippocampal (p < .05) volume compared to males. No sex differences in parahippocampal volume were noted among WNHs. Biological sex, rather than ApoE4 status, was a greater predictor of hippocampal volume among Hispanic and WNH females. These findings add to the mixed literature on sex differences in dementia research and highlight continued emphasis on ethnic populations to elucidate on neurodegenerative disparities.

Automatic measurements of fetal intracranial volume from 3D ultrasound scans.

Three-dimensional fetal ultrasound is commonly used to study the volumetric development of brain structures. To date, only a limited number of automatic procedures for delineating the intracranial volume exist. Hence, intracranial volume measurements from three-dimensional ultrasound images are predominantly performed manually. Here, we present and validate an automated tool to extract the intracranial volume from three-dimensional fetal ultrasound scans. The procedure is based on the registration of a brain model to a subject brain. The intracranial volume of the subject is measured by applying the inverse of the final transformation to an intracranial mask of the brain model. The automatic measurements showed a high correlation with manual delineation of the same subjects at two gestational ages, namely, around 20 and 30 weeks (linear fitting R2(20 weeks) = 0.88, R2(30 weeks) = 0.77; Intraclass Correlation Coefficients: 20 weeks=0.94, 30 weeks = 0.84). Overall, the automatic intracranial volumes were larger than the manually delineated ones (84 ± 16 vs. 76 ± 15 cm3; and 274 ± 35 vs. 237 ± 28 cm3), probably due to differences in cerebellum delineation. Notably, the automated measurements reproduced both the non-linear pattern of fetal brain growth and the increased inter-subject variability for older fetuses. By contrast, there was some disagreement between the manual and automatic delineation concerning the size of sexual dimorphism differences. The method presented here provides a relatively efficient way to delineate volumes of fetal brain structures like the intracranial volume automatically. It can be used as a research tool to investigate these structures in large cohorts, which will ultimately aid in understanding fetal structural human brain development.

AI-based medical e-diagnosis for fast and automatic ventricular volume measurement in patients with normal pressure hydrocephalus

Based on CT and MRI images acquired from normal pressure hydrocephalus (NPH) patients, using machine learning methods, we aim to establish a multimodal and high-performance automatic ventricle segmentation method to achieve an efficient and accurate automatic measurement of the ventricular volume. First, we extract the brain CT and MRI images of 143 definite NPH patients. Second, we manually label the ventricular volume (VV) and intracranial volume (ICV). Then, we use the machine learning method to extract features and establish automatic ventricle segmentation model. Finally, we verify the reliability of the model and achieved automatic measurement of VV and ICV. In CT images, the Dice similarity coefficient (DSC), intraclass correlation coefficient (ICC), Pearson correlation, and Bland–Altman analysis of the automatic and manual segmentation result of the VV were 0.95, 0.99, 0.99, and 4.2 ± 2.6, respectively. The results of ICV were 0.96, 0.99, 0.99, and 6.0 ± 3.8, respectively. The whole process takes 3.4 ± 0.3 s. In MRI images, the DSC, ICC, Pearson correlation, and Bland–Altman analysis of the automatic and manual segmentation result of the VV were 0.94, 0.99, 0.99, and 2.0 ± 0.6, respectively. The results of ICV were 0.93, 0.99, 0.99, and 7.9 ± 3.8, respectively. The whole process took 1.9 ± 0.1 s. We have established a multimodal and high-performance automatic ventricle segmentation method to achieve efficient and accurate automatic measurement of the ventricular volume of NPH patients. This can help clinicians quickly and accurately understand the situation of NPH patient's ventricles.

Evaluating the Effectiveness of Minimally Invasive Surgery Using External Ventricular Drainage Systems in Draining Chronic Subdural Hematomas.

To show the effectiveness of minimally invasive surgery with external ventricular drainage systems (EVDS) in the treatment of chronic subdural hematomas by comparing with it with classic surgery with closed drainage system (CDS) with intracranial hematoma volume measurements and predict infection risks by comparing two different surgeries with each other with intracranial air volume measurements. From 2014 to 2020, the data of 28 patients with chronic subdural hematoma who underwent surgeries two large burr holes, saline irrigation, and CDS or one small burr hole, no saline irrigation, and EVDS were retrospectively who had preoperative computed tomography (CT) postoperative 1st-3rd day CT, and postoperative 7th-10th day CT were included in the study. Pre- and postoperative subdural liquid collection volumes and postoperative intracranial air volumes were measured using Sectra Medical Workstation. Results were compared between these two groups. There were no significant differences in the preoperative and 7th-10th day liquid volumes between these two groups (p > 0.05). There were significant differences in the postoperative 1st-3rd day air volume between these two groups (p < 0.001). The statistical results showed that surgeries with EVDS are as effective as surgeries with CDS in draining chronic subdural hematomas. We also determined that the intracranial air volume is significantly less in surgeries with EVDS. For this reason, we believe that EVDS can reduce the risk of postoperative infection.

Intracranial Brain Volume (ICV) Measurement in Epileptic Male Patient: A 3D CT Study

Objective: Intracranial volume (ICV) is one of the reliable indicators of neurodegenerative disease and premature brain size. Epilepsy is considered a neurological disorder. We aimed to measure ICV in epileptic male samples to identify the relation of ICV and epilepsy control status for their better treatment purpose. Methods: This retrospective study was done using CT images of age-matched control and epileptic male samples. All samples were collected from the archive of the Department of Radiology, Universiti Sains Malaysia (USM) from the 2010-2017 period. A total of 34 male samples were used for this study in two groups, control (n=17) and epileptic (n=17) groups. Control males were those who came for the CT scan and no disease was found. And epileptic male patients were those who came for routine checkups due to epilepsy. MITK 3M3 software was used for the ICV measurement. 2D CT images were converted to 3D CT images to measure intracranial brain volume (ICV) in each group. Two reviewers measured ICV and a reliability test was done between reviewers. Results: According to first reviewer, there is no significant (p=0.455) difference between control, (1287.82 (151.79) mm) and epileptic (1283.28 (65.48) mm) male groups. Results of second reviewer also showed no significant difference (p=0.400) between control (1299.58(144.81)) mm and epileptic (1283.88 (76.08)) groups. Average measurements also did not reveal any significant difference between groups, control is 1293.7 (144.81) mm and the epilepsy group is 1283.58 (69.90) mm (p=0.114). Reliability test results revealed an acceptable internal consistency level in control (97%, p&lt;0.001) and epileptic (77%, p=0.003) groups. Conclusion: We concluded that epilepsy does not affect ICV in the male population. Further study is recommended to seek other indicators which might be affected by epilepsy in the male population. J MEDICINE 2021; 22: 95-99

Association of Hispanic/Latino background and brain structure in Hispanics/Latinos from the SOL‐INCA MRI study

AbstractBackgroundThe Hispanic Community Health Study/Study of Latinos (HCHS/SOL) is a representative, community‐based study of Hispanics and Latinos across the US that seeks to understand health disparities within this heterogeneous population. The Study of Latinos ‐ Investigation of Neurocognitive Aging MRI (SOL‐INCA MRI) is an ancillary MRI study to HCHS/SOL focused on the genetic influence and cognitive impact of age‐ and disease‐related brain measures. Brain structure undergoes substantial development and remodeling from birth through adulthood. Intracranial volume is a measure of maximum brain development, which is under substantial genetic and environmental influences, and is an independent marker of cognitive resilience. We report the influence of self‐described background on intracranial volume, brain tissue and cortical thickness measures for 1388 individuals studied to date.MethodHispanics and Latinos (ages 35.9‐85.2 years; 66% female) underwent MRI and analysis at the Imaging of Dementia and Aging (IDeA) laboratory using previously published methods. MRI outcomes of interest included supratentorial intracranial volume (TCV), image segmentation into white matter, gray matter, total brain, and regional cortical thickness. Background was categorized as Cuban, Central American, Dominican, Mexican, Puerto Rican and South American. We performed association analysis using linear regression models accounting for sex, height, background, and their interactions.ResultHeight was positively associated with TCV. Women had significantly smaller TCV than men (Table 1). TCV did not vary significantly with age. After adjusting for age, gender, height, and interactions, TCV measures varied significantly by background, and were greatest for Dominicans. Cuban’s and Mexican’s TCV measures were significantly smaller than Dominican’s (Figure 1). Cerebral gray matter volume as a residual of TCV was also significantly greater for Dominicans as compared to all other backgrounds (Table 2). Residuals of brain, gray and white matter varied significantly across backgrounds (Figure 2). Finally, cortical thickness measures varied significantly by background and brain region, being greatest for both Dominicans and Puerto Ricans (Figure 3).ConclusionBrain development results from multiple factors including gene, environment, and gene‐environment interactions. Investigating the genetic and environmental causes of the heterogeneity of brain measures in SOL‐INCA‐MRI are likely to lead to discoveries related to both brain development and possibly brain aging.

Postnatal Cranial Characterization in a Mouse Model of Cortex‐Specific Overexpression of BAF170

The BRG1/BRM-associated factor (BAF) chromatin remodeling complexes are composed of the mutually exclusive brahma or brahma-related gene 1 ATPases, along with several other structural subunits and their isoforms. BAF complexes serve specific functions in widely different cell types and developmental processes. Mammalian BAF170, a subunit of chromatin remodeling complex mSWI/SNF, is an intrinsic factor controlling cortical size. It was previously reported that conditional deletion of BAF170 promotes indirect neurogenesis by increasing the pool of intermediate progenitors and results in an enlarged cortex, whereas cortex specific BAF170 overexpression results in a smaller cortex. However, the influence of cortex specific BAF170 overexpression on size and shape of the craniofacial complex, specifically the skull, is not well understood. We hypothesized that the skull phenotype of mice with cortex specific BAF170 overexpression may include indirect effects of the reduced cortex including reduced intracranial volume and linear distance measures of the skull relative to unaffected littermates. To further understand the influence of cortex-specific conditional overexpression of BAF170 on the cranial phenotype of young mice, we examined two postnatal ages of the cortex specific BAF170 overexpression mouse model. Here, we combine measures of gross observation (body weight, body length, brain weight) and of 3D micro-computed tomography imaging of the head (overall skull length, cranial length, cranial height, cranial width, intracranial volume) at 28 (P28; N=6) and 42 (P42; N=12) days of age to assess the influence of BAF170 overexpression on skull morphology as compared to unaffected littermates. In our small sample, gross examination of the brain indicated an obviously distinctive brain morphological phenotype at both ages, including a visibly smaller cortex, in mice with overexpression of BAF170. Results showed few other differences at P28, although brain weight and skull width were reduced in mice with cortex specific BAF170 overexpression as compared to unaffected littermates. By P42, brain weight was no longer different between the genotypes, but cranial length, width, and height were all smaller. Additionally, intracranial volume was reduced in mice overexpressing BAF170 at P42. These results suggest that BAF170 overexpression in mice, which specifically supervises development of a smaller cortex, affects their skull phenotype in terms of size and possibly shape at P28 and P42, with potentially increased differences occurring with age. Further morphometric exploration is necessary to determine whether additional craniofacial differences exist at other ages.

Intracranial Volume Measured and Correlated to Cephalic Index in Syndromic and Nonsyndromic Anterior Brachycephaly.

Premature fusion of both coronal sutures (anterior brachycephaly) alters skull shape and potentially affects intracranial volume (ICV). Currently little is known about preoperative ICV in anterior brachycephaly. Aim is to measure preoperative ICV and compare this with normative data. Additionally, ICV will be correlated to most used clinical method of quantification: cephalic index (CI). Preoperative patients with anterior brachycephaly (age, ≤12 months) were included and categorized by syndrome (when present). Computed tomography scans were used for ICV measurement by manual segmentation (OsiriX (Fondation OsiriX, Geneva, Switzerland)). Intracranial volume of each subgroup was compared with Lichtenberg normative cranial volume growth curves for controls. Cephalic index was calculated and correlated to ICV using Pearson correlation coefficient. Thirty-four patients with both syndromic and nonsyndromic anterior brachycephaly were included: 17 with Apert syndrome, 6 with Muenke syndrome, 5 with Saethre Chotzen syndrome, 3 with Crouzon, 1 with craniofrontonasal dysplasia, and 2 nonsyndromal. Mean age at preoperative computed tomography scan was 4 months (1-10 months). Mean ICV was 847.31 cm3 (473.91-1459.22 cm3). Nineteen of 34 patients had skull volumes between ±2 SD curves of Lichtenberg, none of the patients had an ICV smaller than -2 SD and 15 of 34 had an ICV larger than +2 SD. Mean ICV in Apert syndrome was 829.85 cm3 (473.91-1061.53 cm3), in Muenke syndrome 942.06 cm3 (768.02-1136.75 cm3), in Saethre Chotzen syndrome 779.72 cm3 (609.21-1002.95 cm3), in Crouzon syndrome 700.57 cm3 (652.31-784.32 cm3), in craniofrontonasal dysplasia 738.97 cm3, and in the nonsyndromal group 1154.64 cm3 (850.07-1459.22 cm3). Apert had a mean greater than +2SD above the mean, the other subgroups had a mean within normal ranges (±2 SD). Correlation between severity of brachycephaly and overall ICV was low (r = 0.42). Mean preoperative ICV in both syndromic and nonsyndromic anterior brachycephaly was 847.31 cm3. Intracranial volume in anterior brachycephaly is in 55.9% between normal ranges (±2 SD). In 44.1% ICV was greater than +2 SD, especially in Apert syndrome (11/16 Apert patients). None of the included patients had a deviant small ICV of less than -2 SD. Additionally, low correlation between ICV and CI (r = 0.42) was found and therefore CI is not suitable for estimating ICV in anterior brachycephaly.

Discussion: Automated Measurement of Intracranial Volume Using Three-Dimensional Photography.

Discussion: Automated Measurement of Intracranial Volume Using Three-Dimensional Photography.

Automated Measurement of Intracranial Volume Using Three-Dimensional Photography.

Current methods to analyze three-dimensional photography do not quantify intracranial volume, an important metric of development. This study presents the first noninvasive, radiation-free, accurate, and reproducible method to quantify intracranial volume from three-dimensional photography. In this retrospective study, cranial bones and head skin were automatically segmented from computed tomographic images of 575 subjects without cranial abnormality (average age, 5 ± 5 years; range, 0 to 16 years). The intracranial volume and the head volume were measured at the cranial vault region, and their relation was modeled by polynomial regression, also accounting for age and sex. Then, the regression model was used to estimate the intracranial volume of 30 independent pediatric patients from their head volume measured using three-dimensional photography. Evaluation was performed by comparing the estimated intracranial volume with the true intracranial volume of these patients computed from paired computed tomographic images; two growth models were used to compensate for the time gap between computed tomographic and three-dimensional photography. The regression model estimated the intracranial volume of the normative population from the head volume calculated from computed tomographic images with an average error of 3.81 ± 3.15 percent (p = 0.93) and a correlation (R) of 0.96. The authors obtained an average error of 4.07 ± 3.01 percent (p = 0.57) in estimating the intracranial volume of the patients from three-dimensional photography using the regression model. Three-dimensional photography with image analysis provides measurement of intracranial volume with clinically acceptable accuracy, thus offering a noninvasive, precise, and reproducible method to evaluate normal and abnormal brain development in young children. Diagnostic, V.

Linked patterns of biological and environmental covariation with brain structure in adolescence: a population-based longitudinal study

Adolescence is a period of major brain reorganization shaped by biologically timed and by environmental factors. We sought to discover linked patterns of covariation between brain structural development and a wide array of these factors by leveraging data from the IMAGEN study, a longitudinal population-based cohort of adolescents. Brain structural measures and a comprehensive array of non-imaging features (relating to demographic, anthropometric, and psychosocial characteristics) were available on 1476 IMAGEN participants aged 14 years and from a subsample reassessed at age 19 years (n = 714). We applied sparse canonical correlation analyses (sCCA) to the cross-sectional and longitudinal data to extract modes with maximum covariation between neuroimaging and non-imaging measures. Separate sCCAs for cortical thickness, cortical surface area and subcortical volumes confirmed that each imaging phenotype was correlated with non-imaging features (sCCA r range: 0.30–0.65, all PFDR < 0.001). Total intracranial volume and global measures of cortical thickness and surface area had the highest canonical cross-loadings (|ρ| = 0.31−0.61). Age, physical growth and sex had the highest association with adolescent brain structure (|ρ| = 0.24−0.62); at baseline, further significant positive associations were noted for cognitive measures while negative associations were observed at both time points for prenatal parental smoking, life events, and negative affect and substance use in youth (|ρ| = 0.10−0.23). Sex, physical growth and age are the dominant influences on adolescent brain development. We highlight the persistent negative influences of prenatal parental smoking and youth substance use as they are modifiable and of relevance for public health initiatives.

Brain aging in major depressive disorder: results from the ENIGMA major depressive disorder working group

Major depressive disorder (MDD) is associated with an increased risk of brain atrophy, aging-related diseases, and mortality. We examined potential advanced brain aging in adult MDD patients, and whether this process is associated with clinical characteristics in a large multicenter international dataset. We performed a mega-analysis by pooling brain measures derived from T1-weighted MRI scans from 19 samples worldwide. Healthy brain aging was estimated by predicting chronological age (18–75 years) from 7 subcortical volumes, 34 cortical thickness and 34 surface area, lateral ventricles and total intracranial volume measures separately in 952 male and 1236 female controls from the ENIGMA MDD working group. The learned model coefficients were applied to 927 male controls and 986 depressed males, and 1199 female controls and 1689 depressed females to obtain independent unbiased brain-based age predictions. The difference between predicted “brain age” and chronological age was calculated to indicate brain-predicted age difference (brain-PAD). On average, MDD patients showed a higher brain-PAD of +1.08 (SE 0.22) years (Cohen’s d = 0.14, 95% CI: 0.08–0.20) compared with controls. However, this difference did not seem to be driven by specific clinical characteristics (recurrent status, remission status, antidepressant medication use, age of onset, or symptom severity). This highly powered collaborative effort showed subtle patterns of age-related structural brain abnormalities in MDD. Substantial within-group variance and overlap between groups were observed. Longitudinal studies of MDD and somatic health outcomes are needed to further assess the clinical value of these brain-PAD estimates.

Changes in the intracranial volume from early adulthood to the sixth decade of life: A longitudinal study

Normal brain-aging occurs at all structural levels. Excessive pathophysiological changes in the brain, beyond the normal one, are implicated in the etiology of brain disorders such as severe forms of the schizophrenia spectrum and dementia. To account for brain-aging in health and disease, it is critical to study the age-dependent trajectories of brain biomarkers at various levels and among different age groups.The intracranial volume (ICV) is a key biological marker, and changes in the ICV during the lifespan can teach us about the biology of development, aging, and gene X environment interactions. However, whether ICV changes with age in adulthood is not resolved.Applying a semi-automatic in-house-built algorithm for ICV extraction on T1w MR brain scans in the Dutch longitudinal cohort (GROUP), we measured ICV changes. Individuals between the ages of 16 and 55 years were scanned up to three consecutive times with 3.32±0.32 years between consecutive scans (N = 482, 359, 302). Using the extracted ICVs, we calculated ICV longitudinal aging-trajectories based on three analysis methods; direct calculation of ICV differences between the first and the last scan, fitting all ICV measurements of individuals to a straight line, and applying a global linear mixed model fitting. We report statistically significant increase in the ICV in adulthood until the fourth decade of life (average change +0.03%/y, or about 0.5 ml/y, at age 20), and decrease in the ICV afterward (−0.09%/y, or about −1.2 ml/y, at age 55). To account for previous cross-sectional reports of ICV changes, we analyzed the same data using a cross-sectional approach. Our cross-sectional analysis detected ICV changes consistent with the previously reported cross-sectional effect. However, the reported amount of cross-sectional changes within this age range was significantly larger than the longitudinal changes. We attribute the cross-sectional results to a generational effect.In conclusion, the human intracranial volume does not stay constant during adulthood but instead shows a small increase during young adulthood and a decrease thereafter from the fourth decade of life. The age-related changes in the longitudinalmeasure are smaller than those reported using cross-sectional approaches and unlikely to affect structural brain imaging studies correcting for intracranial volume considerably. As to the possible mechanisms involved, this awaits further study, although thickening of the meninges and skull bones have been proposed, as well as a smaller amount of brain fluids addition above the overall loss of brain tissue.

Correlation of Intracranial Volume With Head Surface Volume in Patients With Multisutural Craniosynostosis.

Intracranial volume (ICV) is an important parameter for monitoring patients with multisutural craniosynostosis. Intracranial volume measurements are routinely derived from computed tomography (CT) head scans, which involves ionizing radiation. Estimation of ICV from head surface volumes could prove useful as 3D surface scanners could be used to indirectly acquire ICV information, using a non-invasive, non-ionizing method.Pre- and postoperative 3D CT scans from spring-assisted posterior vault expansion (sPVE) patients operated between 2008 and 2018 in a single center were collected. Patients were treated for multisutural craniosynostosis, both syndromic and non-syndromic. For each patient, ICV was calculated from the CT scans as carried out in clinical practice. Additionally, the 3D soft tissue surface volume (STV) was extracted by 3D reconstruction of the CT image soft tissue of each case, further elaborated by computer-aided design (CAD) software. Correlations were analyzed before surgery, after surgery, combined for all patients and in syndrome subgroups.Soft tissue surface volume was highly correlated to ICV for all analyses: r = 0.946 preoperatively, r = 0.959 postoperatively, and r = 0.960 all cases combined. Subgroup analyses for Apert, Crouzon-Pfeiffer and complex craniosynostosis were highly significant as well (P < 0.001).In conclusion, 3D surface model volumes correlated strongly to ICV, measured from the same scan, and linear equations for this correlation are provided. Estimation of ICV with just a 3D surface model could thus be realized using a simple method, which does not require radiations and therefore would allow closer monitoring in patients through multiple acquisitions over time.

Abstract WP74: Automated Measurement of Cerebral Atrophy and Outcome in Endovascular Thrombectomy

Background and Purpose: Methods of identifying ischemic stroke patients with a greater probability of poor outcome following endovascular thrombectomy (EVT) might improve shared treatment decision-making between patients, families and physicians. Visually-graded cerebral atrophy is associated with worse functional outcome following EVT. We used an objective, automated method to measure cerebral atrophy and investigated whether this was associated with functional outcome in EVT patients. Methods: Consecutive EVT patients from a single-center registry were studied. CT brain scans were segmented with a combination of a validated U-Net and Hounsfield unit thresholding. Intracranial cerebrospinal fluid (CSF) volume was used as a marker of cerebral atrophy and calculated as a proportion of total intracranial volume. The primary outcome was functional independence, defined as a 3-month modified Rankin Scale (mRS) score of 0-2. Results: 360 EVT patients were included. Functional independence was achieved in 204 (56.7%) patients. The mean±SD CSF volume was 9.0±4.7% of total intracranial volume. Multivariable regression demonstrated that increasing CSF volume was associated with reduced functional independence (OR=0.65 per 5% increase in CSF volume; 95% CI, 0.48- 0.89; P=0.007) and higher 3-month mRS scores (common OR=1.59 per 5% increase in CSF volume; 95% CI, 1.05-2.41; P=0.03). Conclusions: Cerebral atrophy determined by automated measurement of intracranial CSF volume is associated with functional outcome in patients undergoing EVT. If validated in future studies, this simple, objective, and automated imaging marker could potentially be incorporated into decision-support tools in order to improve shared treatment decision making.