Barry Brunsden

Washington University in St. Louis, San Luis, Missouri, United States

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Publications (26)135.56 Total impact

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    ABSTRACT: Three-dimensional (3-D) reconstructions of computed tomography (CT) and magnetic resonance (MR) brain imaging studies are a routine component of both clinical practice and clinical and translational research. A side effect of such reconstructions is the creation of a potentially recognizable face. The Health Insurance Portability and Accountability Act of 1996 (HIPAA) Privacy Rule requires that individually identifiable health information may not be used for research unless identifiers that may be associated with the health information including "Full face photographic images and other comparable images ..." are removed (de-identification). Thus, a key question is: Are reconstructed facial images comparable to full-face photographs for the purpose of identification? To address this question, MR images were selected from existing research repositories and subjects were asked to pair an MR reconstruction with one of 40 photographs. The chance probability that an observer could match a photograph with its 3-D MR image was 1 in 40 (0.025), and we considered 4 successes out of 40 (4/40, 0.1) to indicate that a subject could identify persons' faces from their 3-D MR images. Forty percent of the subjects were able to successfully match photographs with MR images with success rates higher than the null hypothesis success rate. The Blyth-Still-Casella 95% confidence interval for the 40% success rate was 29%-52%, and the 40% success rate was significantly higher ( P < 0.001) than our null hypothesis success rate of 1 in 10 (0.10).
    No preview · Article · Jan 2009 · IEEE transactions on information technology in biomedicine: a publication of the IEEE Engineering in Medicine and Biology Society
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    ABSTRACT: Three Dimensional (3D) reconstructions of Computed Tomography (CT) and Magnetic Resonance (MR) brain imaging studies are a routine component of both clinical practice and clinical and translational research. A side effect of such reconstructions is the creation of a potentially recognizable face. The Health Insurance Portability & Accountability Act of 1996 (HIPAA) Privacy Rule requires that individually identifiable health information may not be used for research unless identifiers that may be associated with the health information including Full face photographic images and other comparable images are removed (de-identification). Thus a key question is, are reconstructed facial images comparable to full-face photographs for the purpose of identification? To address this question MR images were selected from existing research repositories and subjects were asked to pair an MR reconstruction with one of 40 photographs. The chance probability that an observer could match a photograph with its 3D MR image was 1 in 40 (0.025), and we considered 4 successes out of 40 (4/40, 0.1) to indicate that a subject could identify persons faces from their 3D MR images. Forty percent of the subjects were able to successfully match photographs with MR images with success rates higher than the null hypothesis success rate. The Blyth-Still-Casella 95% CI for the 40% success rate was 29% to 52%, and the 40% success rate was significantly higher (P < 0.001) than our null hypothesis success rate of 1 in 10 (0.10).
    No preview · Article · Dec 2008 · IEEE transactions on information technology in biomedicine: a publication of the IEEE Engineering in Medicine and Biology Society
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    ABSTRACT: While 3-dimensional (3D) imaging by computed tomography has long been desirable for research and treatment of cochlear-implant patients, technical challenges have limited its wide application. Recent developments in scanner hardware and image processing techniques now allow image quality improvements that make clinical applications feasible. Validation experiments were performed to characterize a new methodology and its imaging performance.
    Preview · Article · Jul 2007 · Journal of Digital Imaging
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    ABSTRACT: A new technique for determining the position of each electrode in the cochlea is described and applied to spiral computed tomography data from 15 patients implanted with Advanced Bionics HiFocus I, Ij, or Helix arrays. ANALYZE imaging software was used to register 3-dimensional image volumes from patients' preoperative and postoperative scans and from a single body donor whose unimplanted ears were scanned clinically, with micro computed tomography and with orthogonal-plane fluorescence optical sectioning (OPFOS) microscopy. By use of this registration, we compared the atlas of OPFOS images of soft tissue within the body donor's cochlea with the bone and fluid/ tissue boundary available in patient scan data to choose the midmodiolar axis position and judge the electrode position in the scala tympani or scala vestibuli, including the distance to the medial and lateral scalar walls. The angular rotation 0 degrees start point is a line joining the midmodiolar axis and the middle of the cochlear canal entry from the vestibule. The group mean array insertion depth was 477 degrees (range, 286 degrees to 655 degrees). The word scores were negatively correlated (r = -0.59; p = .028) with the number of electrodes in the scala vestibuli. Although the individual variability in all measures was large, repeated patterns of suboptimal electrode placement were observed across subjects, underscoring the applicability of this technique.
    No preview · Article · May 2007 · The Annals of otology, rhinology & laryngology. Supplement

  • No preview · Article · Jan 2007 · American Journal of Physical Anthropology
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    ABSTRACT: Martin et al. claim that they have two endocasts from microcephalics that appear similar to that of LB1, Homo floresiensis. However, the line drawings they present as evidence lack details about the transverse sinuses, cerebellum, and cerebral poles. Comparative measurements, actual photographs, and sketches that identify key features are needed to draw meaningful conclusions about Martin et al.'s assertions.
    Full-text · Article · May 2006 · Science
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    ABSTRACT: The brain of Homo floresiensis was assessed by comparing a virtual endocast from the type specimen (LB1) with endocasts from great apes, Homo erectus, Homo sapiens, a human pygmy, a human microcephalic, specimen number Sts 5 (Australopithecus africanus), and specimen number WT 17000 (Paranthropus aethiopicus). Morphometric, allometric, and shape data indicate that LB1 is not a microcephalic or pygmy. LB1's brain/body size ratio scales like that of an australopithecine, but its endocast shape resembles that of Homo erectus. LB1 has derived frontal and temporal lobes and a lunate sulcus in a derived position, which are consistent with capabilities for higher cognitive processing.
    Full-text · Article · May 2005 · Science
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    ABSTRACT: A collaborative effort between Washington University in St. Louis and Spencer Technologies in Seattle, WA has been undertaken to create a multimodal D reconstruction of the human cochlea and vestibular system. The goal of this project is to improve the accuracy of in vivo CT reconstructions of implanted cochleae, and to expand the knowledge of high-resolution anatomical detail provided by orthogonal-plane optical sectioning (OPFOS). At WUSL, computed tomography (CT) images of the cochlea are used to determine the position of cochlear implant electrodes relative to target auditory neurons. The cochlear implant position is determined using pre- and post-operative CT scans. The CT volumes are cross-registered to align the semicircular canals and internal auditory canal, which have a unique configuration in 3-D space. The head of a human body donor was scanned with a clinical CT device, after which the temporal bones were removed, fixed in formalin and trimmed prior to scanning with a laboratory Micro CT scanner. Following CT, the temporal bones were sent to the OPFOS Imaging Lab at Spencer Technologies for a further analysis. 3-D reconstructions of CT and OPFOS imaging modalities were compared, and results are presented. [Work supported by NIDCD Grants R44-03623-5 and R01-00581-13.]
    No preview · Article · Jan 2003 · The Journal of the Acoustical Society of America
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    ABSTRACT: This study extended the findings of Ketten et al. [Ann. Otol. Rhinol. Laryngol. Suppl. 175:1-16 (1998)] by estimating the three-dimensional (3D) cochlear lengths, electrode array intracochlear insertion depths, and characteristic frequency ranges for 13 more Nucleus-22 implant recipients based on in vivo computed tomography (CT) scans. Array insertion depths were correlated with NU-6 word scores (obtained one year after SPEAK strategy use) by these patients and the 13 who used the SPEAK strategy from the Ketten et al. study. For these 26 patients, the range of cochlear lengths was 29.1-37.4 mm. Array insertion depth range was 11.9-25.9 mm, and array insertion depth estimated from the surgeon's report was 1.14 mm longer than CT-based estimates. Given the assumption that the human hearing range is fixed (20-20,000 Hz) regardless of cochlear length, characteristic frequencies at the most apical electrode (estimated with Greenwood's equation [Greenwood DD (1990) A cochlear frequency--position function of several species--29 years later. J Acoust. Soc. Am. 33: 1344-1356] and a patient-specific constant as) ranged from 308 to 3674 Hz. Patients' NU-6 word scores were significantly correlated with insertion depth as a percentage of total cochlear length (R = 0.452; r2 = 0.204; p = 0.020), suggesting that part of the variability in word recognition across implant recipients can be accounted for by the position of the electrode array in the cochlea. However, NU-6 scores ranged from 4% to 81% correct for patients with array insertion depths between 47% and 68% of total cochlear length. Lower scores appeared related to low spiral ganglion cell survival (e.g., lues), aberrant current paths that produced facial nerve stimulation by apical electrodes (i.e., otosclerosis), central auditory processing difficulty, below-average verbal abilities, and early Alzheimer's disease. Higher scores appeared related to patients' high-average to above-average verbal abilities. Because most patients' scores increased with SPEAK use, it is hypothesized that they accommodated to the shift in frequency of incoming sound to a higher pitch percept with the implant than would normally be perceived acoustically.
    Full-text · Article · Oct 2002 · Journal of the Association for Research in Otolaryngology
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    ABSTRACT: The objective of this study was to create three-dimensional (3D) images for the histomorphological study of osteons. Medical imaging technology was used to register digitized 2D images of serial decalcified histological sections of bone, to segment the tissues of interest from the surrounding tissues, and to create 3D reconstructions from the segmented structures. Examination of the 3D reconstructions did not support suggestions in the literature that osteons have a spiraling organization. In contrast, the 3D reconstructions indicated that osteons have a complex pattern of organization that is dominated by branching. Examination of the reconstructions also suggested that osteons described in the literature as being dumbbell shaped are actually artifacts of the plane of sectioning. This study demonstrated the applicability of imaging and visualization technology developed for the 3D reconstruction of medical images to the reconstruction of digitized 2D images of serial sections of bone and additionally demonstrated the feasibility of using 3D reconstructions for the histomorphological study of osteons.
    No preview · Article · Nov 1999 · Calcified Tissue International
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    ABSTRACT: A phantom representation of typical colon structures with precisely known geometrical measurements was designed and fabricated. Computed tomography (CT) data were collected using a range of protocols typical for spiral CT colonography. Analysis methods were developed to measure the acquired geometry of the phantom data and characterize distortions/degradation. Simple models were proposed to explain the trends in degradation in the acquisition process versus scanner protocol. Preliminary results indicate that degradation due to CT acquisition will not significantly impact the detection of clinically relevant lesions (dimensions greater than 1 cm). However, the CT acquisition process does place a lower limit on detection size of several millimeters.
    No preview · Article · May 1999 · Proceedings of SPIE - The International Society for Optical Engineering
  • Paul K. Commean · Barry S. Brunsden · Kirk E. Smith · Michael W. Vannier
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    ABSTRACT: The ability to measure and visualize shape change (deformation) of a residual limb within and between prostheses is an important step toward improved prosthetic fit assessment. The objective was to develop measurement and visualization methods for below-knee residual limb soft tissue shape change after donning and loading a prosthesis to detect small shape changes (30mm or less). Spiral X-ray computed tomography imaging was utilized to acquire 3D volumetric data of the below-knee residual limb and prosthesis in situ from poor- and a good-fitting prostheses without and with a load. A new sum projection depth-shaded cylindrical mapping technique to measure and visualize small changes in shape was developed. From the volumetric data, the relative displacement of small lead markers placed on the residual limb's skin surface were measured using multiplanar reconstruction images and cylindrical maps. Displacement measurements averaging 15mm or less were obtained. The precision and accuracy was 1mm and 2mm, respectively, when measuring the shape change or deformation of the skin surface from the sum projection cylindrical maps. The skin surface deformation was at least 7mm or greater when comparing marker locations between scans with the prostheses in situ. These new image-based measurement and visualization methods provide a feasible means for measuring and displaying lower extremity residual limb shape change within and between different prostheses with and without loading.
    No preview · Article · Aug 1998 · Archives of Physical Medicine and Rehabilitation
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    ABSTRACT: To compare the reliability of radiodensity measurements made from dental radiographs with manual and a novel computer-intensive methods. As part of a prospective study of postmenopausal women, a series of seven vertical bitewing radiographs were taken of 36 patients. One of each set of radiographs was repeated. The original and the corresponding duplicate radiographs were used in this study. Radiographs were digitized at 50 microns spatial resolution and 12-bit gray-scale resolution. For the Manual Method, original and duplicate radiographs were manually cropped to improve image homology, histogram matched and mean pixel gray-scale values determined for an alveolar bone ROI within each image. For the computer-intensive method, images were put into registration with ANALYZE software (Mayo Foundation, Rochester, MINN, USA), cropped automatically, histogram matched and color-coded on the basis of the per cent difference. Alveolar bone ROIs adjacent to clinical crowns and root surfaces whose color code indicated less than a 5% change were sampled. Method error (ME) and the coefficient of variation of method error (CVME) were calculated. With the Manual Method the SD between original and duplicate measures was 95.21 out of 4096 gray scale values; ME = 67.32; CVME = 3.78%. For the computer-intensive method, the corresponding values were 54.74, 38.71, and 2.29%. The new computer-intensive method resulted in a 40% improvement over the Manual Method in the precision of radiodensity measurements.
    Full-text · Article · Aug 1998 · Dentomaxillofacial Radiology
  • G C Conroy · G W Weber · H Seidler · P V Tobias · A Kane · B Brunsden
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    ABSTRACT: Two- and three-dimensional computer imaging shows that endocranial capacity in an approximately 2.8- to 2.6-million-year-old early hominid cranium (Stw 505) from Sterkfontein, South Africa, tentatively assigned to Australopithecus africanus, is approximately 515 cubic centimeters. Although this is the largest endocranial capacity recorded for this species, it is still markedly less than anecdotal reports of endocranial capacity exceeding 600 cubic centimeters. No australopithecine has an endocranial capacity approaching, let alone exceeding, 600 cubic centimeters. Some currently accepted estimates of early hominid endocranial capacity may be inflated, suggesting that the tempo and mode of early hominid brain evolution may need reevaluation.
    No preview · Article · Jul 1998 · Science
  • Michael W. Vannier · Paul K. Commean · Barry S. Brunsden · Kirk E. Smith
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    ABSTRACT: Lower-limb prosthesis quality-of-fit assessment is purely subjective in routine clinical practice, relying on patient reports of discomfort, erythema (localized pain), and palpation. Wide variations in residual limb physical characteristics and conditions preclude a rigid approach to prosthesis prescription. With relatively long life expectancy for many lower-limb amputees, clinicians measure outcome in terms of return to work and quality of life, which have important social and economic consequences. An objective quantitative metric of fit that predicts functional outcome has not been described to date. Volumetric CT scanning provides in situ static 3D determination of residual limb soft tissue changes caused by the prosthesis socket. This mapping aids in prosthesis design and evaluation
    No preview · Article · Oct 1997 · IEEE Computer Graphics and Applications
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    ABSTRACT: The emerging techniques of 3D spiral CT for 'virtual colonoscopy' show promise as a noninvasive screening modality for the detection of polyps. Our purpose was to evaluate three key post-processing parameters required for depiction of colonic polyps using perspective volume rendering (PVR): image reconstruction, window setting, and opacity map assignment of the attenuation histogram. Spiral CT scans of two different patients with known polyps confirmed by colonoscopy were performed. First, image quality was compared between images generated after interpolation of raw projection data and interpolation of reconstructed image data for longitudinal voxel dimensions of 1x, 2x, 4x, 6x and 8x in-plane voxel dimensions. Second, the dimensions of colonic polyps relative to haustral folds were measured on PVR images for various window settings and compared to similar measures performed on photography performed at colonoscopy. Third, a double sigmoidal and a stair-step opacity function were each applied to a 3D PVR image of a polyp, and quantitative differences in image smoothness were compared using a texture analysis method. In conclusion, spiral CT images reconstructed with 50 percent overlap and displayed with a standard display window permit accurate depiction of polyp dimensions relative to surrounding structures on PVR windows. Image artifacts may be suppressed with use of a double sigmoidal opacity map. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints
    No preview · Article · May 1997 · Proceedings of SPIE - The International Society for Optical Engineering
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    ABSTRACT: Stereology was used to measure frontal lobe volume on magnetic resonance imaging (MRI) scans in a multi-observer repeated-measures trial in 17 adults. Prior to measurement, MR image volumes were reoriented into coronal sections perpendicular to the bicommissural plane. Three observers blinded to subject identify repeatedly used fixed grid stereology to estimate frontal lobe volumes, defined as all sections of the frontal lobe anterior to the anterior commissure. The lateral ventricles were excluded. Stereological measurement yielded high repeatability and precision, and was time efficient for the raters. The coefficient of error was 0.03. The inter-rater correlation coefficient = 0.95 for three raters; intra-rater correlation coefficients = 0.95-0.98. A comparison was made between stereological and traditional edge tracing measurement of the frontal lobe volumes. The overall correlation between the two methods was 0.95. The use of internal landmarks to define orientation and 3-D orthogonal views to define frontal lobe boundaries on 3-D images was critical to obtaining repeatable measurements. Frontal lobe volumetry by brain MR used to estimate small differences postulated to occur in certain psychiatric and neurologic disorders requires high precision and repeatability. Stereology, a semi-automated method, can reliably estimate frontal lobe volumes. This method may distinguish small frontal lobe volume differences within individuals and between groups.
    Full-text · Article · Nov 1996 · Psychiatry Research
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    ABSTRACT: Prefrontal cortex volumetry by brain magnetic resonance (MR) is required to estimate changes postulated to occur in certain psychiatric and neurologic disorders. A semiautomated method with quantitative characterization of its performance is sought to reliably distinguish small prefrontal cortex volume changes within individuals and between groups. Stereological methods were tested by a blinded comparison of measurements applied to 3D MR scans obtained using an MPRAGE protocol. Fixed grid stereologic methods were used to estimate prefrontal cortex volumes on a graphic workstation, after the images are scaled from 16 to 8 bits using a histogram method. In addition images were resliced into coronal sections perpendicular to the bicommissural plane. Prefrontal cortex volumes were defined as all sections of the frontal lobe anterior to the anterior commissure. Ventricular volumes were excluded. Stereological measurement yielded high repeatability and precision, and was time efficient for the raters. The coefficient of error was <EQ 0.03. The overall 3-way inter- rater ICC equals 0.95; intra-rater ICCs equals 0.95 - 0.98. The use of specific internal landmarks to define prefrontal cortex boundaries on 3D images was critical to obtaining accurate measurements. MR prefrontal cortex volumetry by stereology can yield accurate and repeatable measurements. Small frontal lobe volume reductions in patients with brain disorders such as depression and schizophrenia can be efficiently assessed using this method. Publisher's Citation: Yvette I. Sheline ; Kevin J. Black ; Daniel Y. Lin ; Joseph Pimmel ; Po Wang ; John W. Haller ; John G. Csernansky ; Mokhtar Gado ; Ronald K. Walkup ; Barry S. Brunsden and Michael W. Vannier, "MRI volumetry of prefrontal cortex", Proc. SPIE 2434, Medical Imaging 1995: Image Processing, 766 (May 12, 1995); doi:10.1117/12.208749; http://dx.doi.org/10.1117/12.208749
    No preview · Article · May 1995 · Proceedings of SPIE - The International Society for Optical Engineering
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    ABSTRACT: Goal: To estimate hippocampal volumes from in vivo 3D magnetic resonance (MR) brain images and determine inter-rater and intra- rater repeatability. Objective: The precision and repeatability of hippocampal volume estimates using stereologic measurement methods is sought. Design: Five normal control and five schizophrenic subjects were MR scanned using a MPRAGE protocol. Fixed grid stereologic methods were used to estimate hippocampal volumes on a graphics workstation. The images were preprocessed using histogram analysis to standardize 3D MR image scaling from 16 to 8 bits and image volumes were interpolated to 0.5 mm3 isotropic voxels. The following variables were constant for the repeated stereologic measures: grid size, inter-slice distance (1.5 mm), voxel dimensions (0.5 mm3), number of hippocampi measured (10), total number of measurements per rater (40), and number of raters (5). Two grid sizes were tested to determine the coefficient of error associated with the number of sampled 'hits' (approximately 140 and 280) on the hippocampus. Starting slice and grid position were randomly varied to assure unbiased volume estimates. Raters were blind to subject identity, diagnosis, and side of the brain from which the image volumes were extracted and the order of subject presentation was randomized for each of the raters. Inter- and intra-rater intraclass correlation coefficients (ICC) were determined. Results: The data indicate excellent repeatability of fixed grid stereologic hippocampal volume measures when using an inter-slice distance of 1.5 mm and a 6.25 mm2 grid (inter-rater ICCs equals 0.86 - 0.97, intra- rater ICCs equals 0.85 - 0.97). One major advantage of the current study was the use of 3D MR data which significantly improved visualization of hippocampal boundaries by providing the ability to access simultaneous orthogonal views while counting stereological marks within the hippocampus. Conclusion: Stereological estimates of 3D volumes from 2D MR sections provide an inexpensive, unbiased and efficient way of determining brain structural volumes. The high precision and repeatability demonstrated with stereological MR volumetry suggest that these methods may be efficiently used to measure small volume reductions associated with schizophrenia and other brain disorders.
    No preview · Chapter · Sep 1994
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    ABSTRACT: The resolution requirements were determined for detection of incremental alveolar bone loss from digitized Ektaspeed radiographs. Ten clinical radiographs were examined with a calibrated optical microscope to measure the smallest feature of interest discernible for alveolar bone. Images of trabeculae > 100 microns in diameter could be identified, but smaller ones could not be resolved. The Nyquist Criterion requires sampling with 50 microns (or smaller) pixels to measure such features. Numerous 25 microns Ag aggregates were present. Fifty microns resolution is a practical compromise between noise level and feature resolution. In another example of 10 bitewings digitized at 8 bit grey scale, about half the available range was used for alveolar bone, resulting in uncertainty, over a range of 2 optical density (OD) units, of about 1.42% at the average OD for alveolar bone (1.1). With the same radiographs digitized at 12 bit resolution, over 2000 of 4096 grey scales were used with a corresponding uncertainty of about 0.09%. Twelve-bit precision was also able to resolve smaller increments in an aluminium stepwedge than was 8 bit precision. Twelve-bit grey scale and 50 microns spatial resolution are recommended for alveolar bone densitometry performed with Ektaspeed radiographs.
    Full-text · Article · Aug 1994 · Dentomaxillofacial Radiology