Search PubMed⌕ Search

Biomedical subjects

T P Naidich

Publications and source records attributed to T P Naidich.

At least 19 recordsLinked to original sources
PubMed2003

Distension technique to improve computed tomographic evaluation of oral cavity lesions.

BACKGROUND: The apposing mucosa of the oral cavity makes the computed tomographic identification of a clinically obvious mass difficult. Contrast distension techniques have been used in radiology to evaluate for presence of a "hidden" mass. OBJECTIVE: To illustrate the utility of distending the oral cavity with air, water, or contrast to display otherwise obscure oral cavity lesions. PATIENTS AND METHODS: In 3 normal subjects and 5 patients with biopsy-proved oral cavity lesions, serial contiguous 3-mm axial and coronal computed tomographic scans were obtained before and after distension of the oral cavity using intraoral air or water. Air distension was achieved by having the subjects perform a modified Valsalva maneuver during the scan acquisitions. Fluid distension was obtained using approximately 40 mL of water. RESULTS: In each case, the contrast successfully distended the oral cavity, separating the mucosal surfaces. Gingivobuccal lesions that were obscured by apposition of the lips and cheeks to the gums and teeth, or by apposition of the tongue to the inner margins of the gums and teeth, were clearly demonstrated. Lesions involving or extending into the retromolar trigone were also well demonstrated using this distension technique. CONCLUSIONS: Computed tomographic display of the anatomy and pathology of the oral cavity can be improved simply by distending the oral cavity using air or water as a contrast medium. This technique successfully shows lesions that are obscured by the apposing surfaces of the vestibule and the oral cavity proper, improving computed tomographic diagnosis.

Air↗
PubMed2001

Intramedullary neurenteric cysts of the spine. Case report and review of the literature.

This case of a 68-year-old woman with a low-thoracic intramedullary neurenteric cyst is notable for clinical presentation, cyst location, intraoperative findings, and imaging characteristics. The patient's postoperative course was complicated by neurological deterioration and a neuropathic pain syndrome. Potential causes of these complications are discussed, as are possible ways to reduce the risk of their occurrence.

Aged↗
PubMed2001

The parasagittal line: an anatomic landmark for axial imaging.

BACKGROUND AND PURPOSE: No validated imaging landmark exists for characterizing the medial-lateral position of abnormalities at the high convexity-parasagittal region. Our understanding of the courses and deflections of the upper cerebral sulci is limited. Our purpose, therefore, was to define a frontooccipital line with reproducible anatomic relations to the upper cerebral gyri and sulci and to validate that line for use as an anatomic landmark by specific analysis of the gyral-sulcal relationships along it. METHODS: In 100 subjects of all ages, the gyri and sulci visualized on serial axial CT sections of the upper brain were traced onto a single flat surface to delineate the anatomic relationships among the midline interhemispheric fissure, the paramedian superior frontal sulci (SFS) and intraoccipital sulci (IOS), the medial surface sulci, the high convexity sulci, and the inner table of the skull. These tracings provided a template for drawing a straight, best-fit parasagittal line from the SFS to the IOS and for assessing how reproducibly key anatomic structures align along the parasagittal line. To assure the applicability of the line to MR imaging, selected relationships were retested on serial axial MR sections in the same subjects. RESULTS: The parasagittal line could be drawn in each case and showed reproducible alignment with the SFS, hand-motor area, partes marginales, pars deflections, postcentral "parentheses," distal intraparietal sulci, and IOS. In supraventricular sections, the parasagittal line separated the sulci arising along the medial surface from those arising along the convexity. CONCLUSION: Because the anatomic relationships of the parasagittal line are reproducible, it may serve as a reference line or landmark. The tendency of this line to demarcate medial sulci from convexity sulci suggests immediate application to the definition of vascular territories and vascular watersheds, a topic under active investigation.

Adolescent↗
PubMed2001

The motor cortex: anatomic substrates of function.

This article provides a firm foundation in the gross and microscopic anatomy of the motor cortex. It reviews the sites, Brodmann regions, normal function, and deficits associated with the primary motor cortex, supplementary motor area, presupplementary motor area, and the cingulate motor area in preparation for understanding the functional MR imaging studies that are reviewed in the later articles.

Brain Mapping↗
PubMed2001

Functional magnetic resonance imaging: factors modulating the cortical activation pattern of the motor system.

The use of functional MR imaging (fMRI), especially in a clinical setting, requires knowledge and control of the physiologic factors that can affect the hemodynamic response of the brain. In this article, the authors review the influence of elementary parameters of the motor system such as hemispheric dominance, rate, and force of action, and complexity of a paradigm in determining the cortical fMRI signal change.

Animals↗
PubMed2001

Functional magnetic resonance imaging of human olfaction.

Olfaction is our basic sense phylogenetically and embryologically. Little is known, however, about how the human brain encodes the quality of odors, odor-associated memories, and emotions. Olfactory information is projected from the olfactory bulb to the primary olfactory cortex, which is composed of the anterior olfactory nucleus, the olfactory tubercle, the piriform cortex, the amygdala, the periamygdaloid region, and the entorhinal cortex. From there, the primary olfactory cortex projects to secondary olfactory regions including the hippocampus, ventral striatum and pallidum, hypothalamus, thalamus, orbitofrontal cortex, agranular insular cortex, and cingulate gyrus. Functional MR studies using olfactory stimuli as paradigms show activation of many of these areas and can advance our understanding of odor perception in humans.

Adult↗
PubMed2001

Anatomic substrates of language: emphasizing speech.

This article reviews in detail the gross anatomy of the auditory and language areas, the present concepts of unimodal and multimodal association cortices, the classic model of language, problems with the classic model, and newer approaches to conceptualizing the structural interconnections that subserve audition and language.

Adult↗
PubMed2001

Cervical MR imaging in postural headache: MR signs and pathophysiological implications.

BACKGROUND AND PURPOSE: Postural headache most often occurs after lumbar puncture as post-lumbar puncture headache (PLPH) or, rarely, spontaneously as spontaneous intracranial hypotension headache (SIHH). In this prospective study, we used spinal MR imaging to determine the findings that would assist in the diagnosis of PLPH and SIHH and that would further our pathophysiological understanding of postural headache. METHODS: The study group consisted of 15 healthy volunteers and 20 patients with postural headache: nine with SIHH and 11 with PLPH. The craniocervical junction and the cervical spine were studied using T2-weighted fast spin-echo and T1-weighted spin-echo sequences in the axial and sagittal planes. Follow-up studies were performed in 13 patients. RESULTS: Dilatation of the anterior internal vertebral venous plexus was the most constant finding, present in 17 (85%) of 20 patients with postural headache. Spinal hygromas, whose location as subdural or epidural could not be exactly determined, were present in 14 patients (70%). A focal fluid collection was detected in the retrospinal region at the C1-C2 level in six patients with SIHH and in four patients with PLPH (50%). Tonsillar descent was detected in only one patient, and subtentorial hygroma in five patients. No abnormalities were found in the volunteers. CONCLUSION: The MR signs of dilatation of the venous plexus, presence of spinal hygromas, and presence of retrospinal fluid collections can help to establish the diagnosis of intracranial hypotension. They are probably the result of decreased CSF volume, with the retrospinal fluid collections being a transudate from the venous plexus rather than frank extravasation. Resolution of these signs parallels resolution of the headache.

Adult↗
PubMed2000

Imaging of postnatal maturation of the skull base.

The skull begins to form when mesenchyme thickens and condenses around the developing brain. At the skull base, most of this mesenchyme derives from neural crest, and some arises from general head mesenchyme. This article reviews the patterns for maturation of the ossification, sutures, and synchondroses in the occipital, the sphenoid, and the orbitoseptal regions, and reports additional data derived from specific study of CT scans of the skull base in children and young adults.

Adolescent↗
PubMed2000

Imaging of the osseous, membranous, and perilymphatic labyrinths.

The inner ear is located within the petrous portion of the temporal bone and consists of the membranous, perilymphatic, and the outer osseous labyrinths. Together, these structures form the end organs for mediating hearing and balance. This article provides a detailed review of the neonatal anatomy and development of these structures, knowledge of which derives in great part from advances in CT and sophisticated MR imaging. Current research should soon enable clinicians to identify a wide variety of subtle lesions of the inner ear that heretofore have been inaccessible to imaging diagnosis.

Cochlea↗
PubMed1999

Diffuse meningeal enhancement in patients with overdraining, long-standing ventricular shunts.

The authors report two elderly men with diffuse meningeal enhancement 13 and 21 years following insertion of ventriculojugular shunts. Lumber puncture documenting low CSF pressures suggests that diffuse meningeal enhancement in patients with long-standing ventricular shunts may be secondary to dural venous dilatation rather than meningeal fibrosis. The authors theorize that these elderly patients, neither of whom had postural headache, may be less subject to brain "sag" because of decreased brain weight.

Aged↗
PubMed1997

Imaging anatomy of the normal orbit.

Sectional imaging by CT and MRI now displays the gross anatomy of the orbit in vivo. Gross anatomy, axial and coronal CT, and MRI will be used to review the anatomic features of the orbit critical to image interpretation. Familiarity with the positions, relationships, and normal appearance of the major structures described and illustrated in this article will provide a solid basis for interpreting images of orbital pathology, as discussed in subsequent articles.

Humans↗
PubMed1995

Anatomic relationships along the low-middle convexity: Part I--Normal specimens and magnetic resonance imaging.

Sagittal sections of anatomic specimens and magnetic resonance images well display the individual gyri and sulci along the low-middle convexity. Those familiar with the typical pattern and with the common normal variations will be able to use sagittal magnetic resonance imaging to correctly localize lesions by identifying: (a) the five major rami of the sylvian fissure; (b) the subdivision of the triangular inferior frontal gyrus into the M-shaped partes orbitalis, triangularis, and opercularis by the anterior horizontal and anterior ascending rami of the sylvian fissure; (c) the zig-zag shape of the middle frontal gyrus, which characteristically angles sharply and inferiorly to fuse with the anterior surface of the precentral gyrus; (d) T-shaped bifurcation of the posterior end of the inferior frontal sulcus to form the inferior precentral sulcus; (e) separation of the central sulcus from the sylvian fissure by union of the opercular ends of the precentral and postcentral gyri to form the subcentral gyrus inferior to the central sulcus; (f) narrower sagittal dimension of the postcentral gyrus than the precentral gyrus; (g) horseshoe shape of the supramarginal gyrus perched atop the posterior ascending ramus of the sylvian fissure; (h) similar horseshoe shape of the angular gyrus perched atop the posterior end of the superior temporal sulcus; (i) commonly intercalated accessory presupramarginal and preangular gyri; and (j) the arcuate course of the intraparietal sulcus, which separates the superior from the inferior parietal lobules. The anatomic relationships described are more nearly constant anteriorly than posteriorly. When used as described, they prove helpful in correctly localizing pathology and in planning a surgical approach to lesions that may be difficult to localize on the basis of axial or coronal plane magnetic resonance images.

Brain↗
PubMed1995

Neurovascular imaging.

Neurovascular imaging stresses the role of MR angiography and color flow Doppler sonography in selected congenital vascular anomalies, aneurysms, arteriovenous malformations, arteriosclerotic cerebrovascular disease, and dural sinus thrombosis. The application of North American Symptomatic Carotid Endarterectomy Trial criteria to the diagnosis of carotid artery stenosis and the correlations among radiograph arteriography, sonography, and MR angiography are reviewed in detail. The new clinical advisory on endarterectomy for asymptomatic 60% to 99% carotid stenosis is reviewed as well.

Angiography↗
PubMed1994

Imaging in acute basilar artery thrombosis.

The aim of this study was to review the imaging features in acute (< 24 h) basilar artery thrombosis. CT and MR studies in 11 patients with clinical diagnosis of acute basilar artery thrombosis were retrospectively reviewed. MR angiography was obtained in 4 patients. Correlation with clinical symptoms was performed. Multiple cranial nerve palsies and hemiparesis were the most common clinical symptoms at presentation. CT revealed hyperdense basilar arteries (n = 7) and hypodensities in the posterior circulation territory (n = 8). In one instance, the infarction was hemorrhagic. MR imaging showed absence of flow void within the basilar in 6 patients and MRA (using both PC and TOF techniques) confirmed absence of blood flow in 4 basilar arteries. One week after presentation, 5 patients died. Autopsy was obtained in 1 case and confirmed the diagnosis of basilar artery thrombosis. Basilar artery thrombosis has fairly typical imaging features by both CT and MR. MRA may be used to confirm the diagnosis. Prompt recognition may lead to early thrombolytic treatment and may improve survival.

Acute Disease↗