Experimental validation of geometric and densitometric coronary measurements on the new generation Cardiovascular Angiography Analysis System (CAAS II)

Computer-assisted contour detection and videodensitometric cross sectional area assessment of coronary artery obstructions on the CAAS II system were validated in vitro and in vivo by angiographic cinefilm recording and automated measurement of stenosis phantoms (luminal diameter 0.5, 0.7, 1.0, 1.4, 1.9 mm) which were first inserted in a plexiglass model and then serially implanted in swine coronary arteries. "Obstruction diameter" (OD) and "obstruction area" (OA) values obtained from 10 in vitro and 19 in vivo images at the site of the artificial stenoses were compared with the true phantom dimensions. The in vitro assessment of OD yielded an accuracy of 0.00 +/- 0.11 mm (correlation coefficient: r = 0.98, y = 0.18 + 0.82x, standard error of estimate: SEE = 0.08), whereas the in vivo measurement of OD gave an accuracy of -0.01 +/- 0.18 mm (r = 0.94, y = 0.22 + 0.82x, SEE = 0.15). The assessment of OA gave an accuracy of -0.08 +/- 0.21 mm2 in vitro (r = 0.97, y = 0.08 + 0.99x, SEE = 0.22) and -0.22 +/- 0.32 mm2 in vivo (r = 0.95, y = 0.21 + 1.01x, SEE = 0.33). The mean reproducibility was +/- 0.09 mm for geometric measurements and +/- 0.21 mm2 for videodensitometric assessments, respectively. Thus, due to inherent limitations of the imaging chain, the reliability of geometric coronary measurements is still far superior to videodensitometric assessments of vessel cross sectional areas.

Reduced cortical thickness as an outcome of differential sensitivity to environmental risks in schizophrenia

BACKGROUND

The etiology of schizophrenia is thought to involve differential-likely genetically mediated-sensitivity to environmental exposures. However, examination of differential sensitivity in models of psychopathologic constructs is subject to bias because psychopathology itself may distort exposure assessment. The use of neuroimaging phenotypes, conversely, may provide unbiased evidence for differential sensitivity to environmental exposures. This study examined the impact of two environmental exposures associated with both schizophrenia and magnetic resonance imaging (MRI) cerebral alterations in models of cerebral cortical thickness.

METHODS

T1-weighted MRI scans were acquired from 88 patients with schizophrenia, 98 healthy siblings at higher than average genetic risk for schizophrenia, and 87 control subjects. Freesurfer software was used to measure cortical thickness for 68 brain regions. Associations between 1) cortical thickness and 2) cannabis use and developmental trauma were examined.

RESULTS

A significant group × developmental trauma interaction (χ(2) = 9.65, p = .01), as well as a significant group × cannabis interaction (χ(2) = 6.04, p = .05) was apparent, indicating differential sensitivity of the patient group, which displayed stronger reductions of cortical thickness for both exposures. A similar pattern was found in the sibling-control comparison for cannabis. For developmental trauma, siblings did not differ from control subjects, displaying an increase in cortical thickness with higher levels of trauma.

CONCLUSIONS

The findings suggest that schizophrenia and its genetic liability are associated with differential cerebral cortical sensitivity to developmental environmental exposures such as cannabis. Gene-environment interactions may underlie some of the brain alterations observed in patients with schizophrenia and their relatives.

CAAS. II: A second generation system for off-line and on-line quantitative coronary angiography

The Cardiovascular Angiography Analysis System (CAAS) has been completely redesigned and transferred to a modern platform. The user-friendly environment together with a number of image processing techniques and tools allow easy and fast analysis of cardiovascular angiographic images. These images are obtained either on-line by means of a frame grabber hooked on the video output of the X-ray equipment or off-line by digitising 35-mm cine film frames. In addition, images can be acquired more directly by means of a network link. Images stored on disk in different formats, including MS-DOS, can also be analysed. Accurate and reliable quantitative analysis of coronary stenoses and assessment of their related functional significance may offer the clinician a tool in a stratification of patients at risk. The semireal-time environment will make it possible for the cardiologist to quickly respond to the results of recanalisation procedures while the patient is still in the catheterisation laboratory. The addition of a video front end makes the system available to all clinically relevant X-ray imaging equipment. A detailed comparison with the former CAAS on the basis of analysis of 40 arterial segments in routinely acquired cineangiograms demonstrated no statistically significant differences between the two analysis systems. Repeated analysis of the same segments yielded inter- and intraobserver variabilities for the obstruction diameter of 0.096 and 0.108 mm, respectively. For the computed reference diameter the values are 0.099 and 0.096 mm, respectively, and for the percentage diameter stenosis 4.67 and 5.37%, respectively.

The accuracy and reproducibility of a global method to correct for geometric image distortion in the x-ray imaging chain

A method to correct for geometric image distortion in the x-ray imaging chain, so-called dewarping, has been developed. A global two-dimensional polynomial model of which the degree is optimized is used. The performance of the method has been tested in a number of experiments using images of a plate with a 1 cm spaced wire grid put against the input screen of the x-ray image intensifier (14/17/27 cm). Both offline cine film and online video images were analyzed. The accuracy of the dewarp method was derived from the acquired images and from computer-simulated distorted images. The robustness and reproducibility of the dewarp method was evaluated by means of imaging the grid in various random orientations. Three parameters describing the behavior of the algorithm were considered. One is the reproducibility of the location of a dewarped position. The second parameter is the reproducibility of the distance between two adjacent dewarped positions as a measure of the reproducibility of the size of an object under investigation. The third parameter is the reproducibility of the pixel size in the plane of the calibration plate. The major results are: the reproducibility of the location of a dewarped position was 0.01-0.04 mm for cine film and 0.04-0.07 mm for video images. The coefficient of variation of the distance between two dewarped positions was 0.04%-0.11% for cine film and 0.15%-0.18% for video images. The dewarp algorithm turned out to be fast and accurate and the distortion was removed over the whole image field down to a low random residual level. It was found that a random orientation of the grid did not affect the assessment of the distortion nor its correction. The dewarp method proved to be intrinsically robust and highly reliable. Time instability of the imaging chain was the main source of variability in the dewarp results.

Correction for geometric image distortion in the x-ray imaging chain: local technique versus global technique

The local technique to correct for geometric image distortion in the x-ray imaging chain has been implemented and compared with the global correction technique reported previously. Three local correction models were considered, all applied locally within each quadrilateral cell bounded by four adjacent points on a distorted 1.0 cm spaced rectilinear calibration grid. Model 1 uses bilinear interpolation between the correction vectors derived at the four vertices. In Models 2 and 3 a polynomial mapping from distorted to undistorted positions is applied, with Model 2 representing a linear six-parameter correction and Model 3 a nonlinear eight-parameter correction. Both techniques have been analyzed in depth concerning their accuracy. To this end, experimental (35 mm cine film and online video) and computer simulated distorted images of the calibration grid were used. Both radial and sigmoidal distortions were considered in the simulations. The main results are summarized as follows. The accuracy of the local technique depends upon the position within each quadrilateral cell and upon the local direction of the distortion gradient, contrary to the global technique. The accuracy of the local technique decreases with increasing radial as well as sigmoidal distortion. For the global technique only the latter dependency applies. The relationship of the accuracy with the pixel size is different for all models. Finally, the local technique is more sensitive to noise than the global technique. The reproducibility of the correction methods has been evaluated by means of imaging the calibration grid in various orientations with respect to the input screen of the image intensifier. The local technique turns out to reproduce a factor of 4-10 worse than the global technique. In summary, Model 1 is the worst method in all respects, whereas Model 3 is slightly better than Model 2. However, the global technique is to be preferred because it outperforms the local technique on all relevant issues.

Hippocampal volume as marker of daily life stress sensitivity in psychosis

BACKGROUND

Reduced hippocampal size and increased stress sensitivity are associated with psychotic disorder and familial risk for psychosis. However, to what degree the hippocampus is implicated in daily life stress reactivity has not yet been examined. The current study investigated (i) whether familial risk (the contrast between controls, patients and siblings of patients) moderated the relationship between hippocampal volume (HV) and emotional daily stress reactivity and (ii) whether familial risk (the contrast between controls and siblings of patients) moderated the relationship between HV and cortisol daily stress reactivity. Method T1-weighted magnetic resonance imaging (MRI) scans were acquired from 20 patients with schizophrenia, 37 healthy siblings with familial risk for schizophrenia and 32 controls. Freesurfer 5.0.0 was used to measure HV. The experience sampling method (ESM), a structured momentary assessment technique, was used to assess emotional stress reactivity, that is the effect of momentary stress on momentary negative affect (NA). In addition, in the control and sibling groups, cortisol stress reactivity was assessed using momentary cortisol levels extracted from saliva.

RESULTS

Multilevel linear regression analyses revealed a significant three-way interaction between group, HV and momentary stress in both the model of NA and the model of cortisol. Increased emotional stress reactivity was associated with smaller left HV in patients and larger total HV in controls. In line with the results in patients, siblings with small HV demonstrated increased emotional and cortisol stress reactivity compared to those with large HV.

CONCLUSIONS

HV may index risk and possibly disease-related mechanisms underlying daily life stress reactivity in psychotic disorder.

Subjective cognitive failures in patients with hypertension are related to cognitive performance and cerebral microbleeds

Previous studies on the relationship between subjective cognitive failures (SCF) and objective cognitive function have shown inconsistent results. In addition, research on the association between SCF and imaging markers of cerebral small vessel disease is limited. We investigated whether SCF in patients with essential hypertension, who are at high risk of cerebral small vessel disease, are associated with objective cognitive function and magnetic resonance imaging manifestations of cerebral small vessel disease. We included 109 patients with hypertension who underwent extensive neuropsychological assessment, including questionnaires measuring SCF and symptoms of anxiety and depression. Brain magnetic resonance imaging was performed to rate the presence of lacunes, cerebral microbleeds, and perivascular spaces, as well as white matter hyperintensities volume. Results showed significant associations between SCF and objectively measured overall cognition (B=-0.02; 95% confidence interval=-0.03 to -0.005), memory (B=0.02; 95% confidence interval=-0.03 to -0.004), and information processing speed (B=-0.02; 95% confidence interval=-0.03 to -0.001) after adjustment for patient characteristics and vascular risk factors. In addition, SCF were associated with the presence of cerebral microbleeds (odds ratio=1.12; 95% confidence interval=1.02-1.23) after adjustment for patient characteristics and vascular risk factors but not with other imaging markers of cerebral small vessel disease. Our study demonstrates that attention for SCF in patients with hypertension is needed because these may point to lower objective cognitive function, which might be as a result of the presence of cerebral microbleeds. Accordingly, this study emphasizes that neuropsychological assessment and brain imaging need to be considered when patients with hypertension report SCF.

Pituitary volume, stress reactivity and genetic risk for psychotic disorder

BACKGROUND

Hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, associated with increased pituitary volume, may mediate observed alterations in stress reactivity in patients with psychotic disorder. We examined the association between pituitary volume, real-life stress reactivity and genetic liability for psychotic disorder.

METHOD

Pituitary volumes were derived from magnetic resonance imaging (MRI) scans of 20 patients with psychotic disorder, 37 non-psychotic siblings of these patients, and 32 controls. The Experience Sampling Method (ESM) was used to measure emotional stress reactivity [changes in negative affect (NA) associated with daily life stress] in the three groups, and biological stress reactivity (changes in cortisol associated with daily life stress) in siblings and controls. Interactions between group, stress and pituitary volume in models of NA and cortisol were examined.

RESULTS

Groups did not differ in pituitary volume. Patients showed significantly higher emotional stress reactivity than siblings and controls. In addition, emotional stress reactivity increased with increasing pituitary volume to a greater degree in patients than in controls and siblings. Siblings had higher cortisol levels than controls but did not show increased cortisol reactivity to stress. There was no interaction between pituitary volume, stress and group in the model of cortisol.

CONCLUSIONS

Higher pituitary volume was associated with increased emotional stress reactivity in patients with psychotic disorder, siblings and controls. The association was significantly stronger in the patient group, suggesting a process of progressive sensitization mediating clinical outcome.

Evidence that reduced gray matter volume in psychotic disorder is associated with exposure to environmental risk factors

The aim of this study was to examine whether cannabis use, childhood trauma and urban upbringing are associated with total gray matter volume (GMV) in individuals with (risk for) psychotic disorder and whether this is sex-specific. T1-weighted MRI scans were acquired from 89 patients with a psychotic disorder, 95 healthy siblings of patients with psychotic disorder and 87 controls. Multilevel random regression analyses were used to examine main effects and interactions between group, sex and environmental factors in models of GMV. The three-way interaction between group, sex and cannabis (χ² =12.43, p<0.01), as well as developmental urbanicity (χ² = 6.29, p = 0.01) were significant, indicating that cannabis use and developmental urbanicity were associated with lower GMV in the male patient group (cannabis: B= -32.54, p < 0.01; developmental urbanicity: B= -10.23, p=0.03). For childhood trauma, the two-way interaction with group was significant (χ² = 5.74, p = 0.02), indicating that childhood trauma was associated with reduced GMV in the patient group (B=-9.79, p=0.01). The findings suggest that reduction of GMV in psychotic disorder may be the outcome of differential sensitivity to environmental risks, particularly in male patients.

Brain-derived neurotrophic factor/FK506-binding protein 5 genotype by childhood trauma interactions do not impact on hippocampal volume and cognitive performance

In the development of psychotic symptoms, environmental and genetic factors may both play a role. The reported association between childhood trauma and psychotic symptoms could therefore be moderated by single nucleotide polymorphisms (SNPs) associated with the stress response, such as FK506-binding protein 5 (FKBP5) and brain-derived neurotrophic factor (BDNF). Recent studies investigating childhood trauma by SNP interactions have inconsistently found the hippocampus to be a potential target underlying these interactions. Therefore, more detailed modelling of these effects, using appropriate covariates, is required. We examined whether BDNF/FKBP5 and childhood trauma interactions affected two proxies of hippocampal integrity: (i) hippocampal volume and (ii) cognitive performance on a block design (BD) and delayed auditory verbal task (AVLT). We also investigated whether the putative interaction was different for patients with a psychotic disorder (n = 89) compared to their non-psychotic siblings (n = 95), in order to elicit possible group-specific protective/vulnerability effects. SNPs were rs9296158, rs4713916, rs992105, rs3800373 (FKBP5) and rs6265 (BDNF). In the combined sample, no BDNF/FKBP5 by childhood trauma interactions were apparent for either outcome, and BDNF/FKBP5 by childhood trauma interactions were not different for patients and siblings. The omission of drug use and alcohol consumption sometimes yielded false positives, greatly affected explained error and influenced p-values. The consistent absence of any significant BDNF/FKBP5 by childhood trauma interactions on assessments of hippocampal integrity suggests that the effect of these interactions on psychotic symptoms is not mediated by hippocampal integrity. The importance of appropriate statistical designs and inclusion of relevant covariates should be carefully considered.

Differential Time Course of Microstructural White Matter in Patients With Psychotic Disorder and Individuals at Risk: A 3-Year Follow-up Study

BACKGROUND

Although widespread reduced white matter (WM) integrity is a consistent finding in cross-sectional diffusion tensor imaging (DTI) studies of schizophrenia, little is known about the course of these alterations. This study examined to what degree microstructural WM alterations display differential trajectories over time as a function of level of psychosis liability.

METHODS

Two DTI scans with a 3-year time interval were acquired from 159 participants (55 patients with a psychotic disorder, 55 nonpsychotic siblings and 49 healthy controls) and processed with tract-based spatial statistics. The mean fractional anisotropy (FA) change over time was calculated. Main effects of group, as well as group × region interactions in the model of FA change were examined with multilevel (mixed-effects) models.

RESULTS

Siblings revealed a significant mean FA decrease over time compared to controls (B = -0.004, P = .04), resulting in a significant sibling-control difference at follow-up (B = -0.007, P = .03). Patients did not show a significant change over time, but their mean FA was lower than controls both at baseline and at follow-up. A significant group × region interaction (χ² = 105.4, P = .01) revealed group differences in FA change in the right cingulum, left posterior thalamic radiation, right retrolenticular part of the internal capsule, and the right posterior corona radiata.

CONCLUSION

Whole brain mean FA remained stable over a 3-year period in patients with psychotic disorder and declined over time in nonaffected siblings, so that at follow-up both groups had lower FA with respect to controls. The results suggest that liability for psychosis may involve a process of WM alterations.

No Evidence of Association between Childhood Urban Environment and Cortical Thinning in Psychotic Disorder

Background

The alterations in cortical morphology, such as cortical thinning, observed in psychotic disorder, may be the outcome of interacting genetic and environmental effects. It has been suggested that urban upbringing may represent a proxy environmental effect impacting cortical thickness (CT). Therefore, the current study examined whether the association between group as a proxy genetic variable (patients with psychotic disorder [high genetic risk], healthy siblings of patients [intermediate risk] and healthy control subjects [average risk]) and CT was conditional on different levels of the childhood urban environment and whether this was sex-dependent.

Methods

T1-weighted MRI scans were acquired from 89 patients with a psychotic disorder, 95 non-psychotic siblings of patients with psychotic disorder and 87 healthy control subjects. Freesurfer software was used to measure CT. Developmental urban exposure was classified as low, medium, and high, reflecting the population density and the number of moves between birth and the 15^th birthday, using data from the Dutch Central Bureau of Statistics and the equivalent database in Belgium. Multilevel regression analyses were used to examine the association between group, sex, and urban upbringing (as well as their interactions) and cortical CT as the dependent variable.

Results

CT was significantly smaller in the patient group compared to the controls (B = -0.043, p <0.001), but not in the siblings compared to the controls (B = -0.013, p = 0.31). There was no main effect of developmental urbanicity on CT (B = 0.001, p = 0.91). Neither the three-way group × urbanicity × sex interaction (χ² = 3.73, p = 0.16), nor the two-way group × urbanicity interaction was significant (χ² = 0.51, p = 0.77).

Conclusion

The negative association between (familial risk for) psychotic disorder and CT was not moderated by developmental urbanicity, suggesting that reduced CT is not the outcome of familial sensitivity to the proxy environmental factor ‘urban upbringing’.

Semi-metric analysis of the functional brain network: Relationship with familial risk for psychotic disorder

Background

Dysconnectivity in schizophrenia can be understood in terms of dysfunctional integration of a distributed network of brain regions. Here we propose a new methodology to analyze complex networks based on semi-metric behavior, whereby higher levels of semi-metricity may represent a higher level of redundancy and dispersed communication. It was hypothesized that individuals with (increased risk for) psychotic disorder would have more semi-metric paths compared to controls and that this would be associated with symptoms.

Methods

Resting-state functional MRI scans were obtained from 73 patients with psychotic disorder, 83 unaffected siblings and 72 controls. Semi-metric percentages (SMP) at the whole brain, hemispheric and lobar level were the dependent variables in a multilevel random regression analysis to investigate group differences. SMP was further examined in relation to symptomatology (i.e., psychotic/cognitive symptoms).

Results

At the whole brain and hemispheric level, patients had a significantly higher SMP compared to siblings and controls, with no difference between the latter. In the combined sibling and control group, individuals with high schizotypy had intermediate SMP values in the left hemisphere with respect to patients and individuals with low schizotypy. Exploratory analyses in patients revealed higher SMP in 12 out of 42 lobar divisions compared to controls, of which some were associated with worse PANSS symptomatology (i.e., positive symptoms, excitement and emotional distress) and worse cognitive performance on attention and emotion processing tasks. In the combined group of patients and controls, working memory, attention and social cognition were associated with higher SMP.

Discussion

The results are suggestive of more dispersed network communication in patients with psychotic disorder, with some evidence for trait-based network alterations in high-schizotypy individuals. Dispersed communication may contribute to the clinical phenotype in psychotic disorder. In addition, higher SMP may contribute to neuro- and social cognition, independent of psychosis risk.

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Higher SMP was observed at whole brain and hemispheric level in psychotic disorder.

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In patients, lobar SMP was associated with psychotic and cognitive symptoms.

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Trait-based SMP alterations were observed in high schizotypy individuals.

In vivo validation of an experimental adaptive quantitative coronary angiography algorithm to circumvent overestimation of small luminal diameters

The reliability of quantitative coronary angiography (QCA) measurements is of fundamental importance for the study and practice of interventional cardiology. In vivo validation results have consistently reported a tendency for QCA systems to overestimate small luminal diameters. Such a systematic error may result in the underestimation of luminal gain during intracoronary procedures and in the underestimation of progression of coronary artery disease during longitudinal studies. We report the in vivo validation results of an experimental adaptive edge-detection algorithm that was developed to reduce overestimation of small luminal diameters by incorporating a dynamic function of variable kernel size of the derivative operator and variable weighting of the first and second derivatives of the brightness profile. The results of the experimental algorithm were compared to those of the conventional parent edge detection algorithm with fixed parameters. Dynamic adjustment of the edge-detection algorithm parameters was found to improve measurements of small (< 0.8-mm) luminal diameters as evidenced by an intercept of +.07 mm for the algorithm with variable weighting compared to +0.21 mm for the parent algorithm with fixed weighting. A slope of < 1 was found for both the parent and experimental algorithms with subsequent underestimation of large luminal diameters. Systematic errors in a QCA system can be identified and corrected by the execution of objective in vivo validation studies and the consequent refinement of edge-detection algorithms. The overestimation of small luminal diameters may be overcome by the incorporation of a dynamic edge-detection algorithm.(ABSTRACT TRUNCATED AT 250 WORDS)

Testing the estrogen hypothesis of schizophrenia: associations between cumulative estrogen exposure and cerebral structural measures

BACKGROUND

Bone mineral density (BMD), as an indicator of cumulative estrogen exposure, may be reduced in female patients with psychotic disorder (van der Leeuw et al., 2013), possibly reflecting reduced cerebral exposure to estrogen and alterations in neuroprotective effects. To the degree that BMD is a marker of cumulative (endogenous) estrogen exposure, we hypothesized that BMD would be positively associated with cerebral gray and white matter indices.

METHODS

Dual X-ray absorptiometry (DEXA) and magnetic resonance (MRI) scans were acquired in fourteen female patients diagnosed with a psychotic disorder. BMD was expressed in total BMD (g/cm(2)), Z- and T-scores. Cerebral cortical thickness (CT) (as indicator of gray matter status) and fractional anisotropy (FA) (as indicator of white matter integrity) were measured and served as the dependent variables in multilevel random regression models. BMD measures were the independent variables.

RESULTS

Femoral BMD measures were positively associated with CT at trend significance (total BMD: B=0.266, 95% CI: -0.019-0.552, p=0.067; Z-score: B=0.034, 95% CI: 0.001-0.067, p=0.046; T-score: B=0.034, 95% CI: 0.000-0.068, p=0.052). There were no significant associations between femoral BMD measures and FA.

CONCLUSIONS

The data suggest that in women with psychotic disorder, alterations in the neuroprotective effect of estrogen (as measured by BMD) impact cortical gray matter, but not white matter integrity. These findings merit further investigation and, if replicated, would lend support to the estrogen hypothesis of schizophrenia.

The details of structural disconnectivity in psychotic disorder: A family-based study of non-FA diffusion weighted imaging measures

BACKGROUND

Diffusion tensor imaging (DTI) studies in psychotic disorder have shown reduced FA, often interpreted as disturbed white matter integrity. The observed 'dysintegrity' may be of multifactorial origin, as changes in FA are thought to reflect a combination of changes in myelination, fiber organization and number of axons. Examining the structural substrate of the diffusion tensor in individuals with (risk for) psychotic disorder may provide better understanding of the underlying structural changes.

METHODS

DTI scans were acquired from 85 patients with psychotic disorder, 93 siblings of patients with psychotic disorder and 80 controls. Cross-sectional group comparisons were performed using Tract-Based Spatial Statistics (TBSS) on six DTI measures: axial diffusivity (AXD), radial diffusivity (RD), mean diffusivity (MD), and the case linear (CL), case planar (CP) and case spherical (CS) tensor shape measures.

RESULTS

AXD did not differ between the groups. RD and CS values were significantly increased in patients compared to controls and siblings, with no significant differences between the latter two groups. MD was higher in patients compared to controls (but not siblings), with no difference between siblings and controls. CL was smaller in patients than in siblings and controls, and CP was smaller in both patients and siblings as compared to controls.

CONCLUSION

The differences between individuals with psychotic disorder and healthy controls, derived from detailed diffusion data analyses, suggest less fiber orientation and increased free water movement in the patients. There was some evidence for association with familial risk expressed by decreased fiber orientation.

Serum S100B: A proxy marker for grey and white matter status in the absence and presence of (increased risk of) psychotic disorder?

S100B is a protein with dose-dependent neurotrophic and neurotoxic effects. Whether S100B in psychotic disorder mirrors pathophysiological mechanisms (which elicit exacerbation of disease) or compensatory action is unclear, as is its validity as a proxy marker for brain status. Insight may be gained by examining associations between serum S100B and indices of grey (cortical thickness (CT)) and white matter (fractional anisotropy (FA)), in relation to the absence or presence of (increased risk of) psychotic disorder. Blood samples and cerebral magnetic resonance imaging (MRI) scans were acquired in 32 patients with psychotic disorder, 44 non-psychotic siblings of patients with psychotic disorder and 26 controls. Interactions between S100B and group were examined in separate models of CT and FA measures with multilevel regression analyses weighted for number of vertices and voxels (i.e. units of volume) respectively. All analyses were adjusted for sex, age, body mass index (BMI), scan sequence, handedness and highest level of education. Neither CT nor FA was associated with S100B. There were no significant S100B × group interactions (CT: χ² = 0.044, p = 0.978; FA: χ2 = 3.672, p = 0.159). No evidence was present for S100B as a proxy marker of grey or white matter status. The association between S100B and brain measures was not moderated by psychosis risk.