Biomedical subjects

Kenneth L Weiss

Publications and source records attributed to Kenneth L Weiss.

7 recordsLinked to original sources

PubMed2006

Hypertrophic pachymeningitis in rheumatoid arthritis after adalimumab administration.

Tumor necrosis factor-a (TNF-a) inhibition, used in the treatment of rheumatoid arthritis (RA), is associated with central nervous system (CNS) events including new onset and/or exacerbations of pre-existing demyelinating neurological diseases. We describe a patient with refractory RA where adalimumab, a fully humanized IgG1 monoclonal antibody against TNF-a, may have contributed to the development of meningoencephalitis, with brain biopsy suggestive of hypertrophic pachymeningitis, a rare complication of this disease. The patient had recurrence of neurological symptoms upon repeated administration of adalimumab, and resolution of symptoms after withdrawal.

Adalimumab↗

PubMed2006

Automated spine survey iterative scan technique.

Institutional review board approval, with waived consent, was obtained to develop a spine-labeling algorithm with retrospectively obtained deidentified HIPAA-compliant data. An automated magnetic resonance (MR) imaging technique to rapidly survey the entire spine and provide definitive numbering of disks and vertebrae was compared with neuroradiologist assignments in 50 cases. Contiguous two-station sagittal fast gradient-recalled-echo sequences with 35-cm fields of view (FOVs) were preprogrammed for full cervical, thoracic, and lumbar spine coverage (combined 70-cm FOV, seven sections, 15 mm left of to 15 mm right of midline, 4-mm section thickness, 1-mm intersection gap, 512 x 352 matrix, 58/2.0 [repetition time msec/echo time msec], 30 degrees flip angle, 15.6-kHz bandwidth, 42-second acquisition time). In all cases, the neuroradiologist could visualize and definitively number all cervical, thoracic, and lumbar levels on automated spine survey iterative scan technique localizer studies. Automated disk-vertebra detection and numbering were concordant with neuroradiologist assignments in all cases. The entire spine can be surveyed with subminute, submillimeter in-plane resolution MR imaging. Cervical, thoracic, and lumbar vertebrae and disks can be readily identified and definitively numbered by means of visual inspection or semiautomated computer algorithm.

Adolescent↗

PubMed2004

Abnormal frontal white matter tracts in bipolar disorder: a diffusion tensor imaging study.

OBJECTIVES: Prefrontal white matter has been hypothesized to be integral to the pathophysiology of bipolar disorder. Recent morphometric studies however, have not observed changes in white matter in bipolar patients. We hypothesized that changes in prefrontal function in bipolar disorder, widely reported in the literature, may be related to a loss of white matter tract integrity with a resultant dysconnectivity syndrome. In this study we utilized diffusion tensor imaging (DTI) to examine prefrontal white matter in patients with bipolar disorder. METHODS: Nine patients with bipolar disorder and nine healthy controls were recruited. DTI and localizing anatomic data were acquired, and regions of interest (ROIs) identified in the prefrontal white matter at 15, 20, 25, and 30 mm superior to the anterior commissure (AC). Fractional anisotropy (FA) and trace apparent diffusion coefficient (TADC) were compared by ROI between study groups. RESULTS: The FA of ROIs 25 and 30 mm above the AC was significantly reduced in patients with bipolar disorder; FA of all ROIs showed high-medium to large effect sizes. No significant group differences were identified in TADC. CONCLUSIONS: Our findings suggest that a loss of bundle coherence is present in prefrontal white matter. This loss of coherence may contribute to prefrontal cortical pathology in patients with bipolar disorder.

Adult↗

PubMed2004

CT brain prescriptions in Talairach space: a new clinical standard.

BACKGROUND AND PURPOSE: Head CT prescriptions are currently plagued by intra- and intersubject image variance and do not match standardized MR imaging planes. We developed and tested a simple method to improve CT precision and approximate the Talairach reference standard advocated for MR imaging. METHODS: We retrospectively reviewed midline sagittal T2-weighted brain MR images of 126 consecutive patients to determine the mean angle subtended by the Talairach anterior commissure-posterior commissure (AC-PC) line and the hard palate. On the basis of this data set, a new head CT protocol was instituted with pitch similarly prescribed relative to the hard palate as identified on the lateral CT scout film. We then compared the precision of the new protocol, our former method (nominally parallel to the orbito-meatal line) and fixed-gantry angulation. Two head CT studies from 50 consecutive patients imaged with our old protocol and 50 consecutive patients imaged with our new protocol were reviewed for a total of 200 CT examinations. RESULTS: The Talairach AC-PC line was rotated 12.0 degrees +/- 6.1 degrees from the hard palate line and 15.6 degrees +/- 10.1 degrees from the axial plane of the magnet. The new CT protocol approximated the Talairach-referenced MR images obtained at our institution and improved intrapatient CT scan precision compared with fixed-gantry selection (P <.004) and compared with our previous prescription technique (P <.064; P <.025, controlling for excessive head extension). CONCLUSION: By prescribing CT images angled +12 degrees from the hard palate, a structure readily identified by technologists, interscan precision can be improved and Talairach-referenced MR imaging studies can be approximated. Along with AC-PC-referenced MR imaging studies, we advocate this CT protocol as a new clinical standard.

Adolescent↗

PubMed2003

Self-inflicted transorbital and intracranial injury from eyeglasses.

Orbital injuries are commonly seen in the emergency department, and if they are high-energy they can lead to concomitant intracranial injuries. Plain films, CT, MRI, and ultrasound are used in various combinations to evaluate the extent of these injuries. We describe a unique case of self-inflicted transorbital penetrating intracranial injury from the temporal wire rim of a pair of eyeglasses. Imaging well demonstrates the full course of the wire rim in situ, and pathoanatomic correlates are highlighted.

Journal Article↗

PubMed2003

Clinical brain MR imaging prescriptions in Talairach space: technologist- and computer-driven methods.

BACKGROUND AND PURPOSE: Variability in patient head positioning may yield substantial interstudy image variance in the clinical setting. We describe and test three-step technologist and computer-automated algorithms designed to image the brain in a standard reference system and reduce variance. METHODS: Triple oblique axial images obtained parallel to the Talairach anterior commissure (AC)-posterior commissure (PC) plane were reviewed in a prospective analysis of 126 consecutive patients. Requisite roll, yaw, and pitch correction, as three authors determined independently and subsequently by consensus, were compared with the technologists' actual graphical prescriptions and those generated by a novel computer automated three-step (CATS) program. Automated pitch determinations generated with Statistical Parametric Mapping '99 (SPM'99) were also compared. RESULTS: Requisite pitch correction (15.2 degrees +/- 10.2 degrees ) far exceeded that for roll (-0.6 degrees +/- 3.7 degrees ) and yaw (-0.9 degrees +/- 4.7 degrees ) in terms of magnitude and variance (P <.001). Technologist and computer-generated prescriptions substantially reduced interpatient image variance with regard to roll (3.4 degrees and 3.9 degrees vs 13.5 degrees ), yaw (0.6 degrees and 2.5 degrees vs 22.3 degrees ), and pitch (28.6 degrees, 18.5 degrees with CATS, and 59.3 degrees with SPM'99 vs 104 degrees ). CATS performed worse than the technologists in yaw prescription, and it was equivalent in roll and pitch prescriptions. Talairach prescriptions better approximated standard CT canthomeatal angulations (9 degrees vs 24 degrees ) and provided more efficient brain coverage than that of routine axial imaging. CONCLUSION: Brain MR prescriptions corrected for direct roll, yaw, and Talairach AC-PC pitch can be readily achieved by trained technologists or automated computer algorithms. This ability will substantially reduce interpatient variance, allow better approximation of standard CT angulation, and yield more efficient brain coverage than that of routine clinical axial imaging.

Adolescent↗

PubMedDate not supplied

Multiparametric color-encoded brain MR imaging in Talairach space.

Clinical magnetic resonance (MR) imaging of the brain is typically performed in the standard three orthogonal planes of the magnet, with little regard to head positioning. Multiple sequences with different imaging parameters are performed, and gray-scale images are obtained and displayed separately. The authors have implemented, and currently advocate, the routine acquisition of coregistered transverse images after roll, yaw, and pitch correction to Talairach space. Talairach, anterior commissure (AC)-posterior commissure (PC) referenced, stereotactic space has been widely embraced by the neuroscience community. This standardization should lead to more reproducible and readily interpretable MR examinations. A method is described to obtain direct AC-PC referenced (Talairach space) MR images. Sample protocols are provided. Coregistered T1-weighted, T1-weighted with contrast material administration, T2-weighted, fluid-attenuated inversion recovery (FLAIR), MR angiography, fractional anisotropy, and functional MR imaging sequences are presented, depicting a wide range of imaging parameters applied to normal brain anatomy in Talairach space. Illustrative examples of pathology are also provided. Color encoding is discussed and exploited to display and integrate multiparameter MR imaging contrast and white-matter-tract direction (anisotropy). The color composites may reduce the number of images needed for review by a factor of three or four and facilitate interpretation.

Brain↗