Search PubMed⌕ Search

Biomedical subjects

G D Dobben

Publications and source records attributed to G D Dobben.

At least 19 recordsLinked to original sources
PubMed2000

Otogenic intracranial inflammations: role of magnetic resonance imaging.

The clinical course of acute otitis media is usually short, and the process terminates because of the host's immune system, the infection-resistant properties of the mucosal linings, and the susceptibility of the major organisms (beta-hemolytic streptococcus or pneumococcus) to penicillin. However, a small proportion (1% to 5%) of untreated or inadequately treated patients may experience complications. Prior to the development of an intracranial complication of otomastoiditis, warning symptoms or signs may be evident; these include severe earache, severe headache, vertigo, chills and fever, and meningeal symptoms and signs. Increasing headache, particularly temporoparietal headache near the affected ear, often indicates an impending intracranial complication. This symptom, often the only indication of an epidural abscess, demands prompt investigation and medical and surgical intervention. In our experience, computed tomography (CT) permits accurate diagnosis of acute coalescent or latent (masked) mastoiditis and its associated complications. However, magnetic resonance imaging (MRI) remains the study of choice to evaluate otogenic intracranial complications. This article demonstrates the important role of MRI in diagnosing various stages of acute otomastoiditis and its associated complications.

Brain Diseases↗
PubMed1998

Orbital subperiosteal hematoma, cholesterol granuloma, and infection. Evaluation with MR imaging and CT.

Orbital subperiosteal space, a potential space, is an important entity due to its unique anatomy and susceptibility to various pathologic processes. CT scan and MR imaging are important tools in the diagnosis of orbital subperiosteal hematomas, cholesterol granulomas, and infections. MR imaging has emerged as the modality of choice in the evaluation of hematomas and infections of this space due to its multiplanar capability and various imaging sequences giving better information. High-resolution CT scan offers good differentiation in most of these cases. Osseous changes in a cholesterol granuloma is better seen in CT scan, although MR imaging offers better differentiation from epidermoid or dermoid cysts and other subperiosteal process, as well as lacrimal fossa lesions. Subperiosteal abscesses are best evaluated using MR imaging.

Abscess↗
PubMed1989

Potential use of in vivo proton spectroscopy for head and neck lesions.

Early experience with in vivo MRS has shown its potential for obtaining biochemical information, thus enhancing the diagnostic sensitivity of MRI studies. Further work on combined MRI and in vivo MRS is needed, with the goal of characterization and abnormal conditions according to their spectral patterns and for identification of tumor markers. We presented in this communication our preliminary results. It seems that the resonance from melanin can be used as a marker for melanotic tumors.

Biomarkers, Tumor↗
PubMed1988

Central auditory and vestibular pathology.

MR is the radiologic examination of choice when a patient's symptoms indicate the presence of some retrolabyrinthine pathology. CT dynamic studies now permit both heart and brain assessment for poor blood circulation problems of the hindbrain.

Auditory Cortex↗
PubMed1987

Rapid dynamic CT scanning to distinguish schizophrenic from normal subjects.

Rapid dynamic computerized axial tomography (CT) density-time curves were used to detect abnormal brain regions in groups of controls and DSM-III diagnosed schizophrenics. Density-time curves were designated as plateau curves if, following a bolus injection of contrast material, they exhibited a plateau from the peak value rather than a decrease. Five of the 10 schizophrenics versus none of the 11 controls were found to possess two or more plateau curves. The physiological basis for the plateau curves is not known, but an increase in blood-brain-barrier permeability could be involved.

Adult↗
PubMed1987

Paraorbital tumors and tumor-like conditions: role of CT and MRI.

Tumors and tumor-like conditions of the paraorbital tissues that affect the eye usually require CT or MR imaging for complete evaluation. This article provides an overview of the wide variety of pathologic conditions to be considered when a paraorbital tumor is discovered or suspected. Some of the CT and MR imaging features of these disorders that aid in the differential diagnosis are reviewed.

Adenocarcinoma↗
PubMed1987

Dynamic computed tomography and its application to ophthalmology.

In this review of 31 patients, dynamic CT is discussed as a valuable tool in the study of the dynamics of blood flow in patients with unexplained visual problems that may be related to ischemic optic neuropathy. Dynamic CT scans are obtained by rapid-sequence CT imaging during and following a rapid bolus injection of intravenous contrast medium. It demonstrates the initial passage of contrast material through the area of interest, thus giving a true picture of the degree of vascularity and the dynamics of blood flow.

Diagnosis, Differential↗
PubMed1985

Diagnostic potential of CT in neurotological disorders.

The reliability of a neurotological evaluation in differentiating labyrinthine (end organ) lesions from retrolabyrinthine lesions has been well established. The purpose of this communication is to determine the diagnostic potential of computed tomography (CT) in patients suspected of having retrolabyrinthine lesions on the basis of their neurotological evaluations. Our study indicates that the validity of central vestibular and audiometric signs can be best substantiated with CT. The anatomy of neurovascular bundles within the internal auditory canal and cerebellopontine cistern can be readily visualized and identified by CT pneumocisternomeatography. By obtaining appropriate thin CT sections not only can very small lesions be identified but their anatomic locations can also be accurately established. CT pneumocisternomeatography is the method of choice to diagnose an intracanalicular acoustic neuroma. An unusually large vascular loop of the internal auditory canal may be responsible for sensorineural hearing loss and tinnitus in some patients.

Adolescent↗
PubMed1984

Computed tomography of the spine: curved coronal reformations from serial images.

A new imaging format described here uses nonplanar reformations that follow the contour of curved structures intersected by a series of regularly spaced CT scans. The CT scanning procedure is described, and algorithmic details of this new format are presented. A standard set of reformatted images is suggested, and clinical examples are given to illustrate the diagnostic value of this new format.

Adult↗
PubMed1984

CT in the evaluation of the vestibulocochlear nerves and their central pathways. Evaluation of neurotologic disorders.

CT has evolved to become an important technique for the diagnosis of neurotologic disorders. By obtaining thin sections, the central pathway of the vestibulocochlear nerve can be rather properly evaluated with satisfactory clinical correlation when pathology exists. The validity of central vestibular and audiometric signs can be best substantiated with CT. The functional neuroanatomy of the vestibulocochlear and vestibulo-oculomotor systems is discussed. Results of the assessment of endocranial lesions involving the vestibulocochlear system are presented.

Adolescent↗
PubMed1983

High resolution and dynamic sequential computed tomography. Use in the evaluation of glomus complex tumors.

Computed tomography (CT) has been used to investigate the presence, site, and extent of glomus complex tumors. High resolution CT scanning can accurately evaluate invasion of cervical soft tissues, intratympanic or intracranial extension, and bony involvement of the skull base. Glomus tumors can be differentiated by CT angiographic dynamic study from most other tumors in the head and neck because of their profuse vascularity and their intense enhancement seen on dynamic CT during arterial phase. A glomus tympanicum or extension of a glomus jugulare into the hypotypanum can be best demonstrated by high resolution CT using target review image reconstruction. Glomus tumor in the middle ear can be differentiated from other masses by CT dynamic study and the computer-generated density time curves.

Aged↗
PubMed1983

Dandy-Walker syndrome studied by computed tomography and pneumoencephalography.

Based on air studies, some authors have disputed the ability of computed tomography (CT) to diagnose posterior fossa cysts. The authors correlated the pneumoencephalographic, CT, and pathological findings in 4 patients with classic Dandy-Walker syndrome. Three cases had been misdiagnosed as retrocerebellar arachnoid cysts because the fourth ventricle was incorrectly considered normal on brow-up or erect air studies, reflecting the inability of such studies to evaluate an agenetic vermis and deficient posterior medullary velum which are characteristic of Dandy-Walker malformation. Careful correlation with autopsy findings showed that even with complete agenesis of the inferior vermis, if the slit between the cerebellar hemispheres is narrow, the fourth ventricle could be misinterpreted as normal on pneumoencephalography and sagittal CT. Radionuclide studies, a small amount of air, or metrizamide may be needed to determine whether the cyst communicates with the subarachnoid space.

Adult↗
PubMed1982

Computerized tomography of the temporal bone.

Computerized tomography is acquiring an increasingly important role in the radiographic assessment of the temporal bone. In the latest generation of CT scanners, spacial resolution has been reduced to 0.1 cu mm and slice thickness to 1.5 mm. The main advantages of computerized tomography in comparison to multidirectional tomography are the improved contrast of the images and above all the clear demonstration of soft tissue structures and masses within or adjacent to the temporal bone. The following three applications of computerized tomography will be discussed: 1. Evaluation of intratemporal soft tissue masses. Computerized tomography allows differentiation of fluid filled from solid masses and vascular tumors. 2. Assessment of lesions extending outside the temporal bone or into the temporal bone from adjacent structures. In these cases CT will demonstrate the temporal bone involvement and the presence and extension of the intra or extra cranial component of the lesion. 3. Study of the cerebellopontine angle. Computerized tomography with infusion and combined with pneumocisternography comprise the procedure of choice for the diagnosis of acoustic neuromas and other lesions occurring in this area.

Brain Neoplasms↗
PubMed1981

Diagnosis of lipoma of the corpus callosum by CT in five cases.

The value of CT in the easy diagnosis of lipomas and associated anomalies of the corpus callosum, thus avoiding angiography and pneumoencephalography, is reported in five cases. An angiogram was performed in only one of the five cases and provided no additional diagnostic information.

Adult↗