Total Volume Measurements Research Articles

#2186 Lower psoas muscle volume is associated with CKD progression

Abstract Background and Aims Renal rehabilitation is important for keeping quality of life and kidney function of patients with CKD. Psoas muscle is representative of total body muscle and its cross-sectional area divided by squared height (PMI) is known to be associated with CKD prognosis. However, the selection of the slice of computer tomography (CT) used for calculation of PMI is arbitrary and may be a source of bias. Recently, AI technology using raw helical CT data has facilitated the measurement of total volume of the psoas major muscle (PMV), which is theoretically less biased by measurer. The aim of this study is to investigate the association between PMV and the progression of CKD. Method This is a pilot retrospective observational study using electrical health records (EHR) in Hyogo Prefectural Nishinomiya Hospital, Japan. We extracted patients with CKD who had taken abdominal CT in 2021 by nephrologists for evaluation of urological anatomy or clinical reasons. PMV was automatically extracted and measured by SYNAPSE VICENT (Fuji Film Medical), a commercially available software. Baseline laboratory data and patient characteristics were collected through EHR with a margin of 90 days from CT scan. The outcome of CKD progression was defined as a 40% decrease in eGFR from baseline. Survival analysis was performed by using the Cox proportional hazards model. Results We enrolled 145 consecutive CKD patients and excluded 37 whose observation period was less than 90 days. PMV was significantly greater in male than in female, positively associated with younger age and higher body mass index (BMI). PMV adjusted for age, sex, and BMI (adjPMV) decreased in a stepwise manner as baseline CKD stage advanced from G2 (N = 23) to G3b (N = 18) but was comparable in G4 (N = 37) and G5 (N = 6). The subjects were then divided into two groups (High-PMV and Low-PMV) according to whether their adjPMV were greater or less than the median value in each CKD stage. The High- and Low-PMV groups were comparable in age (71 ± 13 vs. 72 ± 13), female sex (42% vs. 45%), eGFR (41 ± 21 vs. 42 ± 22), urinary albumin-to-creatinine ratio (UACR), CRP, the prevalence of diabetes at baseline, respectively. PMI and PMV were significantly greater in High-PMV than in Low-PMV group (7.7 ± 1.8 vs. 5.8 ± 1.6 and 307 ± 110 vs. 205 ± 64, respectively). During the median follow up of 1.6 years, 40 events occurred. Hazards ratio for CKD progression was significantly lower in High-PMV group (0.48 [95% confidence interval: 0.25-0.95]) than Low-PMV group after adjusting for known risk factors (age, sex, eGFR, and UACR). Conclusion Preserved psoas muscle volume measured by a theoretically less biased method may be associated with better prognosis in CKD. A larger study in a different cohort, longitudinal observation, and interventional studies are warranted for future investigation.

Artificial intelligence-based measurements of PET/CT imaging biomarkers are associated with disease-specific survival of high-risk prostate cancer patients

Objective Artificial intelligence (AI) offers new opportunities for objective quantitative measurements of imaging biomarkers from positron-emission tomography/computed tomography (PET/CT). Clinical image reporting relies predominantly on observer-dependent visual assessment and easily accessible measures like SUVmax, representing lesion uptake in a relatively small amount of tissue. Our hypothesis is that measurements of total volume and lesion uptake of the entire tumour would better reflect the disease`s activity with prognostic significance, compared with conventional measurements. Methods An AI-based algorithm was trained to automatically measure the prostate and its tumour content in PET/CT of 145 patients. The algorithm was then tested retrospectively on 285 high-risk patients, who were examined using 18F-choline PET/CT for primary staging between April 2008 and July 2015. Prostate tumour volume, tumour fraction of the prostate gland, lesion uptake of the entire tumour, and SUVmax were obtained automatically. Associations between these measurements, age, PSA, Gleason score and prostate cancer-specific survival were studied, using a Cox proportional-hazards regression model. Results Twenty-three patients died of prostate cancer during follow-up (median survival 3.8 years). Total tumour volume of the prostate (p = 0.008), tumour fraction of the gland (p = 0.005), total lesion uptake of the prostate (p = 0.02), and age (p = 0.01) were significantly associated with disease-specific survival, whereas SUVmax (p = 0.2), PSA (p = 0.2), and Gleason score (p = 0.8) were not. Conclusion AI-based assessments of total tumour volume and lesion uptake were significantly associated with disease-specific survival in this patient cohort, whereas SUVmax and Gleason scores were not. The AI-based approach appears well-suited for clinically relevant patient stratification and monitoring of individual therapy.

Virtual histology of an entire mouse brain from formalin fixation to paraffin embedding. Part 1: Data acquisition, anatomical feature segmentation, tracking global volume and density changes

BackgroundMicrometer-resolution neuroimaging with gold-standard conventional histology requires tissue fixation and embedding. The exchange of solvents for the creation of sectionable paraffin blocks modifies tissue density and generates non-uniform brain shrinkage. New methodWe employed synchrotron radiation-based X-ray microtomography for slicing- and label-free virtual histology of the mouse brain at different stages of the standard preparation protocol from formalin fixation via ascending ethanol solutions and xylene to paraffin embedding. Segmentation of anatomical regions allowed us to quantify non-uniform tissue shrinkage. Global and local changes in X-ray absorption gave insight into contrast enhancement for virtual histology. ResultsThe volume of the entire mouse brain was 60%, 56%, and 40% of that in formalin for, respectively, 100% ethanol, xylene, and paraffin. The volume changes of anatomical regions such as the hippocampus, anterior commissure, and ventricles differ from the global volume change. X-ray absorption of the full brain decreased, while local absorption differences increased, resulting in enhanced contrast for virtual histology. These trends were also observed with laboratory microtomography measurements. Comparison with existing methodsMicrotomography provided sub-10 μm spatial resolution with sufficient density resolution to resolve anatomical structures at each step of the embedding protocol. The spatial resolution of conventional computed tomography and magnetic resonance microscopy is an order of magnitude lower and both do not match the contrast of microtomography over the entire embedding protocol. Unlike feature-to-feature or total volume measurements, our approach allows for calculation of volume change based on segmentation. ConclusionWe present isotropic micrometer-resolution imaging to quantify morphology and composition changes in a mouse brain during the standard histological preparation. The proposed method can be employed to identify the most appropriate embedding medium for anatomical feature visualization, to reveal the basis for the dramatic X-ray contrast enhancement observed in numerous embedded tissues, and to quantify morphological changes during tissue fixation and embedding.

Objective Measurement of 24-Hour Movement Behaviors in Preschool Children Using Wrist-Worn and Thigh-Worn Accelerometers.

In recent years, more attention has been paid towards the study of 24-h movement behaviors (including physical activity (PA), sedentary behavior (SB) and sleep) in preschoolers instead of studying these behaviors in isolation. This study aimed to evaluate the feasibility of using wrist- vs. thigh-worn accelerometers and to report accelerometer-derived metrics of 24-h movement behaviors in preschoolers. A convenience sample of 16 preschoolers (50.0% boys, 4.35 years) and one of their parents were recruited for this study. Preschoolers had to wear the ActivPAL accelerometer (attached to the upper thigh) and Axivity accelerometer (using a wrist band) simultaneously for 7 consecutive days and for 24 h a day. Parents completed an acceptability survey. In total, 16 preschoolers (100.0%) had a minimum of 6 days of valid wrist-worn data, while only 10 preschoolers (62.5%) had a minimum of 6 days of valid thigh-worn data (p = 0.002). When looking at the acceptability, 81.3% of parents indicated that it was easy for their child to wear the Axivity for 7 consecutive days, and 93.8% of parents indicated so for the ActivPAL (p = 0.88). However, some parents stated that the wristband of the Axivity accelerometer was big, which might have affected data collection. Significant differences were found for the measurement of total volume of PA, SB and sleep across 24 h. Total PA was 464.44 min/day (±64.00) with the ActivPAL compared with 354.94 min/day (±57.46) with the Axivity (p < 0.001). The volume of SB was 290.94 min/day (±55.05) with the ActivPAL compared with 440.50 min/day (±50.01) with the Axivity (p < 0.001). The total volume of sleep was also significantly different between both devices (p = 0.001; ActivPAL: 684.63 min/day ± 51.96; Axivity: 645.69 min/day ± 46.78). Overall, parents perceived both devices to be feasible to use for preschoolers. However, future studies are required to validate both devices for the measurement of preschoolers’ 24-h movement behaviors since significant differences in the classification of PA, SB and sleep were found in this small sample.

Is there a relationship between lower lumbar disc herniation and multifidus muscle volume in postmenopausal women?

Background/Aim: Lumbar disc herniation (LDH) is the most common cause of low back pain. It can also cause radiculopathy, sciatica, loss of sensation and motor loss due to pressure on the nerve roots. The multifidus muscle protects the lumbar axis. The aim of this study is to investigate the relationship between volumetric measurements and the degree of atrophy in the multifidus muscles with LDH in postmenopausal women. Methods: This case-control, retrospective study included 207 postmenopausal women with disc herniation on lumbar magnetic resonance imaging (MRI) and 183 reproductive period-premenopausal women with a mean age of 47.12 (10.07) years who were admittd to Adıyaman Training and Research Hospital between March 2020 and March 2021. LDH was detected at L4-L5 and L5-S1 levels on axial T2W lumbar MRI images. At these levels, the multifidus muscle volume was measured from the superior and inferior end plates of the vertebral bodies. The measurement of total volume was called multifidus total muscle volume (M-TMV), and the measurement made from the area without fat infiltration was called multifidus functional muscle volume (M-FMV). The M-TMV/FMV value was obtained to determine the degree of fat atrophy. Statistical analyses were performed, in which P

Assessment of Radiation Dose Delivered and Volume Measurement By Low- and High-Dose Diagnostic Computed Tomography: Anthropomorphic Liver Phantom Study.

Aim:Liver volume measurement is a mandatory test before measure liver surgeries and transplantation. We aimed a study on the difference in volume measurement and radiation dose to an anthropomorphic liver phantom using high-dose and low-dose diagnostic computed tomography (CT).Materials and Methods:Several measurements of the manual total volume measurement done on an anthropomorphic liver phantom mounted with thermoluminescent dosimeter. We exposed the phantom with diagnostic CT, low-dose CT, and a low-dose CT with copper filter.Results:Phantom underwent ten scanning for each exposure. There was no significant difference in the total volume measurement in comparison to the phantom volume. The volume of phantom measured by low-dose CT, low-dose CT with copper phantom, and high-dose CT were 1869 ± 18 cm3, 1852 ± 24 cm3, and 1908 ± 12 cm3, (P = 0.3), respectively. However, the radiation dose delivered was significantly different (1.54 mGy, 0.77 mGy, and 5.84 mGy [P = 0.001], respectively).Conclusion:Total liver volume measurement provides essential clinical information in several clinical conditions. We recommended that the volume measured by a low-dose CT has an excellent correlation with the diagnostic quality CT and should be a routine in the routine clinical practice. CT volumetry achieves the same result while using very less radiation exposure. It may also be used with functional imaging to give complete information.

Standard method for microCT-based additive manufacturing quality control 2: Density measurement

MicroCT is best known for its ability to detect and quantify porosity or defects, and to visualize its 3D distribution. However, it is also possible to obtain accurate volumetric measurements from parts – this can be used in combination with the part mass to provide a good measure of its average density. The advantage of this density-measurement method is the ability to combine the density measurement with visualization and other microCT analyses of the same sample. These other analyses may include detailed porosity or void analysis (size and distribution) and roughness assessment, obtainable with the same scan data. Simple imaging of the interior of the sample allows the detection of unconsolidated powder, open porosity to the surface or the presence of inclusions. The CT density method presented here makes use of a 10?mm cube sample and a simple data analysis workflow, facilitating standardization of the method. A laboratory microCT scanner is required at 15?µm voxel size, suitable software to allow sub-voxel precise edge determination of the scanned sample and hence an accurate total volume measurement, and a scale with accuracy to 3 digits.•MicroCT-based mean density measurement method.•Accurate volume measurement and scale mass.•10 mm cube sample allows standardization and automation of workflow.

THE IMPACT OF HARVESTER CALIBRATION ON THE ACCURACY OF BIRCH VENEER LOGS MEASUREMENTS BY MEASURING DIAMETER IN SHORT INTERVALS USING ELECTRONIC 3D SYSTEMS

Accurate calibration of the harvester head relies on accurate manual log measurements. According to the recommended calibration procedures as proposed by the harvester manufacturer the differences between the volume measurements from harvester measurement system and the caliper-and-tape system must be within ± 3% and harvester diameter measurements within ± 6mm of manual measurements in 80% cases.&#x0D; Requirements in Latvia stipulate that total volume measurement accuracy levels must be within ± 5% of actual volume if veneer or birch logs are being harvested, ± 3% if saw logs are being harvested and ± 10% if pulp wood or fire wood are being harvested. &#x0D; The purpose of this study is to assess the impact of harvester calibration on the accuracy of birch veneer logs measurements by Measuring Diameter in Short Intervals using electronic 3D systems when different double bark volume determination algorithm are used in harvester and stacionar measurement system. The research was carried out in December 2016 in the region Latgale in Latvia. The wood felling area was chosen - Mercurialiosa mel. For volume estimation the sequent measurement equipment were applied: harvester Ponsse ERGO 8W, harvester information system Opti 4G and electronic 3D scanner system Elmes 3600. &#x0D; The research is a continuation to the work done in the project „Harmonisation of piece-by-piece measurement methods of roundwood approved by Standard LVS 82:2003 „Apaļo kokmateriālu uzmērīšana” [6], the project “Harmonization of piece-by-piece measurement methods in all stages of roundwood manufacturing processes” [7] and the project "Investigation and evaluation of the methodology of determination of solid volume according to the stacked volume on roadside and in forwarder loads for logistics purposes in LATVIA" [8].

Morphometric and stereological assessment of the effects of titanium dioxide nanoparticles on the mouse testicular tissue.

To evaluate the effects of titanium dioxide nanoparticles (TNPs) on morphometric and stereological parameters of mouse testis. TNPs are increasingly used in sunscreens, biosensors, food additives, pigments, rubber manufacture, and electronic materials. However, the potential toxicity of these nanoparticles is not well understood. Experimental Groups (TNP-1, TNP-2 and TNP-3) received one of the following treatments daily for 35 days: 75, 150 and 300 mg/kg TNPs respectively. Right testis from each animal was fixed in bouin's solution for measurement of total volume of testis, total volume of seminiferous tubules, total volume of interstitial tissue and total number of Leydig cells by stereological methods. Seminiferous tubule diameter and seminiferous epithelium height were assessed by morphometrical method. The left testicles were homogenized for measurement of testosterone concentration. There was a significant decrease in the weight of testicles in TNP-3 groups. The stereological and morphometrical parameters were significantly changed in TNP-2 and TNP-3 groups. TNP-2 and TNP-3 groups also showed a significant decrease in testosterone concentrations (p < 0.05). This study had demonstrated that TNPs could change stereological and morphometrical parameters of the seminiferous tubules and reduce the number of Leydig cells and testosterone concentration (Tab. 3, Fig. 3, Ref. 35).

Discussion on the concepts of "coordination" and "agility" in terms of physical education

In the scientific and methodological literature and practice of physical education concepts of "coordination" and "agility" are often used synonymously. And discussion about the appropriateness distinguish these concepts is mainly analytical character. Purpose : to evaluate the nature of the relationship metrically between indicators kinesthesia (which characterize the internal processes of interaction in the neuro-muscular system - coordination) and the efficient delivery of a complex exercise (in cooperation man in the external environment of physical education - agility). Material : 77 students surveyed. Students performed on 100 strikes the ball into the goal in terms of golf (10 control measurements). The experiment was conducted for 8 months. 7700 measurement precision of centimeters processed statistically. Calculated reliability of measurements: 100 comparability repetitive beats, accuracy hitting the ball into the goal and the pace of learning in terms of the impact of blows. Results : the total volume measurements was characterized by high variability (V% = 53,5), indicating that the low status of kinesthesia surveyed. This reduces the reliability of the correlation coefficients according to 30 and then 10 of the best students in the general rank in terms of reliability of measurements. Significant correlation occurred only in terms of performance beats the purpose of learning the technique and pace (0,417; n = 30, p &lt;0,05; and 0,677; n = 10, p &lt;0,05). Conclusions : Overall, the results of our study showed that the concept of "coordination" and "agility" should still be distinguished. In some cases, students with a good level of kinesthesia occurred and high mobility in complex locomotion. If we recognize it expedient to continue this discussion, then we must rely on objective, metric information. This information should be obtained in studies with a broad contingent surveyed, consistently show good concentration and high reliability results in a series of repeated measurements.

Morphometric and stereological assessment of the effects of zinc oxide nanoparticles on the mouse testicular tissue.

To evaluate the effects of zinc oxide nanoparticles (ZNPs) on morphometric and stereological parameters of mouse testis. ZNPs are increasingly used in sunscreens, biosensors, food additives, pigments, rubber manufacture, and electronic materials. However, the potential toxicity of these nanoparticles is not well understood. Experimental Groups (ZNP-1, ZNP-2 and ZNP-3) received one of the following treatments daily for 35 days: 5, 50 and 300 mg/kg ZNPs respectively. Right testis from each animal was fixed in bouin's solution for measurement of total volume of testis, total volume of seminiferous tubules, total volume of interstitial tissue and total number of Leydig cells by stereological methods. Seminiferous tubule diameter and seminiferous epithelium height were assessed by morphometrical method. The left testicles were homogenized for measurement of testosterone concentration. There was a significant decrease in the weight of testicles in ZNP-3 groups. The stereological and morphometrical parameters were significantly changed in ZNP-2 and ZNP-3 groups. ZNP-2 and ZNP-3 groups also showed a significant decrease in testosterone concentrations (p < 0.05). This study demonstrated that ZNPs can change stereological and morphometrical parameters of the seminiferous tubules and reduce the number of Leydig cells (Tab. 3, Fig. 3, Ref. 36).

A photogrammetry-based method to measure total and local volume changes of unsaturated soils during triaxial testing

Triaxial tests have been widely used to evaluate soil behaviors. In the past few decades, several methods have been developed to measure the volume changes of unsaturated soil specimens during triaxial tests. Literature review indicates that until now it remains a major challenge for researchers to measure the volume changes of unsaturated soil specimens during triaxial testing. This paper presents a non-contact method to measure the total and local volume changes of unsaturated soil specimens using a conventional triaxial test apparatus for saturated soils. The method is simple and cost-effective, requiring only a commercially available digital camera to take images of an unsaturated soil specimen during triaxial testing from which accurate 3D model of the soil specimen is reconstructed. In this proposed method, the photogrammetric technique is utilized to determine the orientations of the camera where the images are taken and the shape and location of the acrylic cell, multiple optical ray tracings are employed to correct the refraction at the air-acrylic cell and acrylic cell–water interfaces, and a least-square optimization technique is applied to estimate the coordinates of any point on the specimen surface. The paper first discusses the theoretical aspects of the proposed method. An image analysis on a caliper was then used to evaluate the accuracy of photogrammetric analysis in the air. A series of isotropic compression tests on a stainless steel cylinder were used to demonstrate the procedure and evaluate the accuracy of the proposed method, while triaxial shearing tests on a saturated sand specimen were used to exam the capacity of the proposed method for measuring the total and localized volume changes during triaxial testing. Results obtained from the validation tests indicate that the accuracy for the photogrammetry in the air is about 10 µm. The average accuracy for single point measurements in the triaxial tests ranges from 0.056 to 0.076 mm with standard deviations varying from 0.033 to 0.061 mm. The accuracy for total volume measurements is better than 0.25 %.

AB0955 Determining Optimal Hand Position for Reliable Metacarpophalangeal Joint Width Measurements Using Volumetric Methodology by Hr-Pqct

BackgroundJoint space narrowing is an important outcome measure in rheumatoid arthritis, linked tightly to function and disability. High-resolution peripheral quantitative computed tomography (HR-pQCT) allows detection of bone margins with high...

Shape of the basal ganglia in preadolescent children is associated with cognitive performance

Current studies support the belief that high levels of performance and intellectual abilities are associated with increased brain size or volume. With few exceptions, this conclusion is restricted to studies of post-adolescent subjects and to cerebral cortex. There is evidence that “bigger is better” may not pertain to children and further, that there are areas of the brain in which larger structures are associated with cognitive deficits. In 50 preadolescent children (21 girls) a structural survey of the brain (VBM) was conducted to determine and locate areas in which gray matter volume was associated with poor cognitive performance. Only increased gray matter volume in particular areas of the basal ganglia and specifically the putamen was significantly associated with poor performance on tests of memory, response speed and a general marker and subtests of intelligence. Based on the VBM findings, volumetric analysis of basal ganglia structures was performed using FSL/FIRST. However, no significant changes in total volume of putamen or other basal ganglia structures were detected with this analysis. The disagreement between measures of localized gray matter differences and volumetric analysis suggested that there might be local regional deformity rather than widespread volumetric changes of the putamen. Surface analysis with FSL/FIRST demonstrated that bilateral outward deformation of the putamen, but especially the left, was associated with poor performance on several cognitive tests. Expansion of the globus pallidus and caudate nucleus also was associated with poor performance. Moreover a significant association was detected between a reliable test of language-free intelligence and topographically distinct outward and inward deformation of the putamen. Expansion and contraction of the putamen as a predictor of intelligence may explain why this association was not observed with measures of total volume. These results suggest that deformity is a sensitive measure of function, and that distortion of the basal ganglia may be a neurophenotype for risk of developmental impairment.

Relationship between objectively measured physical activity and cardiovascular aging in the general population – The EVIDENT trial

BackgroundAging has been associated with an increase in arterial stiffness. We analyzed the relationship between regular physical activity and cardiovascular aging evaluated by the radial augmentation index (rAIx), ambulatory arterial stiffness index (AASI), pulse pressure (PP) and heart age in subjects without atherosclerotic disease. MethodsA cross-sectional study was performed including 1365 subjects from the EVIDENT trial (mean age 54.9 ± 13.7 years; 60.3% women). As a measure of total volume of physical activity we used counts/minute recorded in an accelerometer (Actigraph GT3X) that participants wore for seven days, collecting data in 60-sec epochs, and respondents with ≥4 valid days were retained for the analysis. Arterial stiffness was evaluated using measures of rAIx, AASI, and central and peripheral PP on the B-pro device. rAIx was adjusted to 75 heart rate(rAIx75). Cardiovascular risk and heart age was estimated by the Framingham Risk Score. ResultsThe median (IQR) of counts/min was 236.9 (176.3–307.8), rAIx75 90 (77–100), sleep PP 40 mmHg (33–47), central PP 39 mmHg (32–47) and heart age 57 years (45–73) and the mean ± SD of the ASSI was 0.44 ± 0.07. We found an inverse correlation between counts/minute and rAIx75 (r = −0.086; p < 0.01), AASI (r = −0.146; p < 0.001), heart age (r = −0.163; p < 0.001) and peripherals PP. These associations were remained after controlling for potential confounders, except for rAIx75. In the multiple regression analysis, after adjustment, an inverse association persisted between counts/minute and AASI, sleep PP and heart age, but not with rAIx75. Accordingly, for every 100 higher counts/minute of accelerometer measures, both AASI and sleep PP would be lower by one measurement unit (beta = −0.979 and −1.031 respectively, p < 0.001) and the estimated heart age by half year (beta = −0.525, p = 0.023). ConclusionsRegular physical activity was inversely associated with parameters related to advanced cardiovascular aging after adjustment for potentially influencing variables.Trial registration: Clinical Trials.gov Identifier: NCT01083082.

A Single mri Slice Does Not Accurately Predict Visceral and Subcutaneous Adipose Tissue Changes During Weight Loss

Previous cross-sectional studies found that a single magnetic resonance imaging (MRI) slice predicts total visceral and subcutaneous adipose tissue (VAT and SAT) volumes well. We sought to investigate the accuracy of trunk single slice imaging in estimating changes of total VAT and SAT volume in 123 overweight and obese subjects who were enrolled in a 24-week CB-1R inverse agonist clinical trial (weight change, −7.7±5.3 kg; SAT change, −5.4±4.9 L, VAT change, −0.8±1.0 L). VAT and SAT volumes at baseline and 24 weeks were derived from whole body MRI images. The VAT area 5–10 cm above L4–L5 (A+5–10) (R2=0.59–0.70, P<0.001) best predicted changes in VAT volume but the strength of these correlations were significantly lower than those at baseline (R2=0.85–0.90, P<0.001). Furthermore, the L4–L5 slice poorly predicted VAT volume changes (R2=0.24–0.29, P<0.001). Studies will require 44–69% more subjects if (A+5–10) is used and 243–320% more subjects if the L4–L5 slice is used for equivalent power of multi slice total volume measurements of VAT changes. Similarly, single slice imaging predicts SAT loss less well than cross-sectional SAT (R2=0.31–0.49 vs. R2=0.52–0.68, p<0.05). Results stayed the same when examined in men and women separately. A single MRI slice 5–10 cm above L4–L5 is more powerful than the traditionally used L4–L5 slice in detecting VAT changes, but in general single slice imaging poorly predicts VAT and SAT changes during weight loss. For certain study designs, multi-slice imaging may be more cost effective than single slice imaging in detecting changes for VAT and SAT.

Use of 3T MRI and an unspoiled 3D fast gradient echo sequence for porcine knee cartilage volumetry: Preliminary findings

To assess the utility of knee cartilage volumetry using an unspoiled fat-suppressed 3D fast gradient echo (FGRE) sequence at 3T. Sagittal magnetic resonance (MR) images were obtained with an unspoiled fat-suppressed 3D FGRE sequence in eight porcine knees. Manual segmentation was used to derive the cartilage volume. This volume was compared to a volume measurement of cartilage scraping specimens obtained by water displacement. Imaging was repeated five times in four of the knees to assess interscan volume measurement reproducibility and calculate precision error. A single 3D dataset was manually segmented five times at weekly intervals to assess intraobserver volume measurement reproducibility. Total cartilage volume obtained from MRI and water displacement correlated well (r = 0.75). The interscan reproducibility of total volume measurements, expressed as the coefficient of variation (CV), was 4.2%, and the precision error (root mean square [RMS] CV) was 4.1%. The CV of intraobserver estimates of total cartilage volume by MRI was 3.6%. Interscan reproducibility of quantification of total cartilage volume and reproducibility of the manual segmentation technique were both high (>95%). Accurate and reproducible cartilage volumetry can be obtained by using a clinical unspoiled fat-suppressed 3D FGRE acquired at 3T MRI.

A new computer tool for systematic evaluation of intracranial volume and its capacity to evaluate the result of the operation for metopic synostosis

The aim of this project was to develop a tool for systematic evaluation of volumetric changes after surgery for craniosynostosis. A computer program using MATLAB was developed to measure total intracranial volume and frontal volume, anterior to the coronary sutures, by multiplying the area with slice thickness of each slice from just above foramen magnum to just beneath the vertex in CT examinations. The ratio between frontal volume and total volume was used for evaluation of the clinical result in 12 patients operated on for metopic synostosis. In 0.625 and 5 millimetre slices the coefficients of variation were 0.00049 and 0.00058, respectively, for measurements of total volume. The highest coefficient of variation was found in postoperative measurements of the frontal volume and was 0.014 in 0.625 millimetre slices. Measurements in 5 millimetre slices resulted in 3.8% ± 1.5% (mean ± SD) lower total volumes and 5.8% ± 5.3% lower frontal volumes than measurements in 0.625 millimetre slices. In patients operated on for metopic synostosis the ratio between frontal volume and total volume increased 25% ± 16% for patients operated on with cranioplasty in combination with a spring (n = 6) and 20% ± 13% for patients operated on with cranioplasty in combination with a bone transplant (n = 6). In summary, this study has developed a tool that can determine frontal and total intracranial volume with little variation. This tool can be used for systematic evaluation of the result of the operation for metopic synostosis.

Metabolic evaluation in patients with recurrent calcium oxalate stones

Objective: This study aimed to evaluate the metabolic changes in patients with recurrent calcium oxalate stones. Materials and methods: We evaluated 143 patients with recurrent oxalate stones and measured serum calcium, phosphate, creatinine, urate, and parathormone. In addition, 24-h urinary output was monitored and collected for the measurement of total volume, pH, citrate, calcium, urate, oxalate, phosphorus, sodium, and magnesium. Results: The mean age of the patients was 42.8±10.8 years, and 132 out of 143 patients (92.3%) had metabolic abnormalities. There were no metabolic abnormalities in only 11 (7.7%) patients. Thirty (20.1%) patients only had one metabolic abnormality, and 102 (71.3%) patients had multiple metabolic abnormalities. Hyperoxaluria was the major metabolic abnormality (64.4%), but we also detected low urinary volume, hypercalciuria, hypocitraturia, hypernatriuria, and hyperuricosuria in 66 (46.2%), 47 (32.8%), 47 (32.8%), 44 (30.8%), and 21 (14.7%) patients, respectively. Conclusion: There were several metabolic abnormalities in patients with recurrent calcium oxalate stones, and the most important were hyperoxaluria, hypercalciuria, hypocitraturia, and low urinary volume. These metabolic abnormalities should be detected and corrected to prevent the recurrence of stones.

A Schizophrenia Risk Gene, ZNF804A, Influences Neuroanatomical and Neurocognitive Phenotypes

ZNF804A is one of the strongest candidate genes for schizophrenia (SZ), yet its function and role in disease pathophysiology are largely unknown. The only in vivo endophenotype study of the SZ-associated SNP (rs1344706) pointed towards effects on brain functional connectivity. We examined the relationship of this SNP to neuroanatomical and neurocognitive phenotypes that were assessed in healthy individuals. Volunteers with no history of psychiatric illness were assessed with structural magnetic resonance imaging (1.5T GE scanner, standard gradient-echo acquisition). Carriers of the minor allele were compared with homozygotes for the T (SZ-associated) allele on measures of total volume of the white matter (WM), gray matter (GM), and cerebrospinal fluid compartments, as well as on voxel-wise measurements of regional brain volumes. After examining the correlation between genotype-associated regions of interest and neurocognitive performance measures, the effects of rs1344706 genotype on a measure of visuomotor performance speed (trails A) were examined in an independent cohort of volunteers. Among healthy subjects, risk allele homozygotes showed larger total WM volumes than carriers of the other allele. Controlling for WM volumes, these same subjects showed reduced GM volumes in several regions comprising the 'default mode network,' including angular gyrus, parahippocampal gyrus, posterior cingulate, and medial orbitofrontal gyrus/gyrus rectus (FDR-corrected p<0.05). The risk allele dosage also predicted impairments on a timed visuomotor performance task (trails A). Results support a role of ZNF804A in phenotypes reflecting altered neural connectivity.