Biomedical subjects

Scott H Faro

Publications and source records attributed to Scott H Faro.

7 recordsLinked to original sources

PubMed2006

Diffusion tensor imaging and fiber-tracking in Marchiafava-Bignami disease.

Marchiafava-Bignami disease, a rare disorder most commonly seen in patients with a history of alcohol consumption, involves demyelination and subsequent necrosis of the corpus callosum. Diffusion tensor imaging demonstrates regional abnormalities in the corpus callosum that are not evident by conventional magnetic resonance imaging (MRI). Furthermore, fiber-tracking demonstrates significant disruption of axonal fiber bundles within the corpus callosum, most marked within the body, corresponding to the clinical finding of interhemispheric disconnection, which is characteristic of the disease.

Alcohol-Induced Disorders↗

PubMed2006

Brain mapping of deception and truth telling about an ecologically valid situation: functional MR imaging and polygraph investigation--initial experience.

PURPOSE: To examine the neural correlates during deception and truth telling by using a functional magnetic resonance (MR) imaging technique and an ecologically valid task and to compare the results with those of a standard polygraph examination. MATERIALS AND METHODS: All subjects gave written informed consent for this HIPAA-approved study, which was approved by the institutional review board of Drexel University. Eleven healthy subjects (five female and six male subjects; mean age, 28.9 years) were randomly assigned to the group of guilty subjects or the group of nonguilty subjects. Each group consisted of two separate functional MR imaging conditions: "lie-only condition" and "truth-only condition." The lie-only condition was used to compare brain activity during a known lie to control questions and a subjective lie to relevant questions. The truth-only condition was used to compare brain activity during a known truthful response to control questions and a subjective truthful response to relevant questions. Functional MR images were acquired with an echo-planar sequence, and statistical analysis was performed. Physiologic responses were measured with a standard four-channel polygraph instrument. RESULTS: During the deception process, specific areas of the frontal lobe (left medial and left inferior frontal lobes), temporal lobe (right hippocampus and right middle temporal gyrus), occipital lobe (left lingual gyrus), anterior cingulate, right fusiform gyrus, and right sublobar insula were significantly active. During the truth telling process, specific areas of the frontal (left subcallosal gyrus or lentiform nucleus) and temporal (left inferior temporal gyrus) lobes were significantly active. The polygraph examination revealed 92% accuracy in deceptive subjects and 70% accuracy in truthful subjects. CONCLUSION: Specific areas of the brain involved in deception or truth telling can be depicted with functional MR imaging.

Adult↗

PubMed2005

Integrated zone comparison polygraph technique accuracy with scoring algorithms.

The Integrated Zone Comparison Technique (IZCT) was utilized with computerized polygraph instrumentation as part of a blind study in the detection of deception. Three scoring algorithms: ASIT Poly Suite (Academy for Scientific Investigative Training's Horizontal Scoring and Algorithm for Chart Interpretation), PolyScore 5.5, and the Objective Scoring System (OSS) were assessed in the interpretation of the charts generated. Where "Inconclusives" were excluded, accuracy for the IZCT with all three algorithms was 100%. When "Inconclusives" were counted as errors, overall accuracy for the IZCT with ASIT Poly Suite was 90% and accuracy with PolyScore and the Objective Scoring System was 72%.

Algorithms↗

PubMed2003

Diffusion tensor imaging of the hippocampal formation in temporal lobe epilepsy.

BACKGROUND AND PURPOSE: Diffusion tensor imaging (DTI) is a noninvasive technique that can be used to assess the integrity of cerebral tissue. The purpose of this study was to assess DTI measurements in the hippocampal formation (HF) and to investigate the role of DTI in lateralizing the seizure focus in temporal lobe epilepsy (TLE). METHODS: We evaluated 12 patients with unilateral TLE and 14 healthy subjects. We collected diffusion-weighted images along six different directions with a b value of 1000 s/mm(2), as well as an image acquired without diffusion weighting (b = 0 s/mm(2)). A 1.5-T imager was used to acquire 17 (3-mm) coronal sections covering the temporal lobes. We compared the mean diffusivity (trace D) and fractional anisotropy (FA) from symmetrical voxels by sampling the anterior HF bilaterally. We compared measurements with the EEG, high-resolution MR imaging, and clinical information. RESULTS: The patient group had significantly increased diffusivity and decreased FA in the HF ipsilateral to the seizure focus, as compared with values in the contralateral HF. When compared with healthy subjects, patients had significantly higher mean diffusivity in the ipsilateral HF; ipsilateral FA values were lower and did not reach statistical significance. Measurements in the contralateral HF did not show differences. Left-right and absolute diffusivity indices lateralized the abnormal HF in eight and five of 12 patients, respectively. CONCLUSION: Abnormal DTI measurements and the epileptogenic HF are associated in unilateral TLE. This finding may reflect hippocampal sclerosis and may aid in presurgical evaluation.

Adult↗

PubMed2002

BOLD fMRI of the visual cortex: quantitative responses measured with a graded stimulus at 1.5 Tesla.

PURPOSE: To measure and quantitatively characterize an activity generated by the neurons of the visual cortex (VC) in response to graded luminous intensity contrast stimuli using a 1.5 Tesla scanner. MATERIALS AND METHODS: Functional magnetic resonance imaging (fMRI) of the vc with the intrinsic blood oxygenation level dependent (BOLD) mechanism was performed by using a paradigm with a 5 x 5 flashing checkerboard pattern flickering eight times per second at eight luminance contrasts presented in a randomized order. The changes of the luminance contrast were obtained by varying the luminance intensity of the white checkerboard squares. Each of eight trials, corresponding to eight luminance contrasts, consisted of six "rest" and six "activation" epochs, repeated five times, amounting to 60 measurement periods per trial. During each epoch, 10 contiguous oblique axial-to-coronal slices covering the calcarine fissure region and parallel to a line through the anterior-posterior commissure (AC-PC) markers were acquired using a gradient-recalled echo planar imaging (GRE-EPI) sequence. RESULTS: The measurements showed changes in the activation extent in the VC following the stimulus' rising luminance intensity contrast. In addition, the fMRI signal in those activated areas present throughout all eight trials, referred to as "common" voxels in this report, showed an increasing trend as a function of the rising luminance intensity contrast. CONCLUSION: These results suggest that the processes of the neuronal recruitment that affects the extent and number of activated neurons, and the neuronal enhancement that defines the magnitude of the neuronal activation are dependent on the luminance intensity contrast. These changes can be visualized and quantified using BOLD fMRI at 1.5 Tesla.

Female↗

PubMed2002

Quantitative functional MR imaging of the visual cortex at 1.5 T as a function of luminance contrast in healthy volunteers and patients with multiple sclerosis.

BACKGROUND AND PURPOSE: In patients with multiple sclerosis (MS), a few preliminary functional MR (fMR) imaging studies of the visual cortex reveal information about magnitude differences between healthy individuals and patients with MS at only a single luminance level. We therefore investigated whether varying luminance contrast levels can help uncover subtle changes in fMR imaging characteristics of the visual cortex in healthy volunteers and patients with MS. METHODS: Blood oxygenation level-dependent fMR imaging signal changes in the primary visual cortex were examined as a function of luminance contrast at 1.5 T in 10 healthy volunteers and nine patients with MS. Ten axial sections through the calcarine fissure were obtained with an echo-planar T2*-weighted imaging sequence (4000/54/1 [TR/TE/excitation]; field of view, 220 mm; voxel size, 1.72 x 1.72 x 5 mm). The imaging series consisted of an alternating 20-second rest epoch (black screen) with a 20-second activation epoch (flickering checkerboard) repeated six times. Each imaging series used a graded increase of eight luminance contrast levels. A paired t test between rest and activation images was used to analyze significant (P <.001) contiguous voxels in the region of interest (primary visual cortex). RESULTS: A progressive increase in fMR imaging activation across all luminance contrast levels in healthy controls and patients with MS was shown. The patients with MS had a significantly lower magnitude in the number of fMR imaging activated voxels at all luminance contrast levels (P <.001). A statistically significant increase in fMR imaging activation (activation threshold) was seen at the second luminance contrast level in controls and at the seventh level in patients with MS. CONCLUSION: Quantifiable changes in blood oxygenation level-dependent signal and a progressive increase in activated voxels within the primary visual cortex with increasing luminance contrast were demonstrated at 1.5 T in controls. The patients with MS showed a significant decrease in the number of activated voxels and an increase in activation threshold compared with healthy controls.

Adult↗

PubMedDate not supplied

Lumbar disk pseudotumor: an unusual presentation of lumbar spinal fracture and stenosis.

We present an unusual case of a primary lumbar disk-space mass that presumably developed secondary to a chronic hyperextension spinal fracture associated with spinal stenosis. This injury resulted in the appearance of a lumbar intervertebral disk-space mass or pseudotumor. The pseudotumor most likely resulted from a prior spinal fracture, leading to a fused hyperextension deformity in a patient with underlying chronic degenerative spinal disease.

Aged↗