Metastatic head and neck cancer: role and usefulness of FDG PET in locating occult primary tumors.

Purpose: To assess the usefulness of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) of the head and neck in locating occult primary lesions in patients with metastatic cervical adenopathy.

Materials And Methods: Seventeen patients with metastatic cervical adenopathy of unknown primary origin were referred for FDG PET of the head and neck. All patients had undergone correlative anatomic imaging within 1 month of FDG PET.

Clinical utility of positron emission tomography with 18F-fluorodeoxyglucose in detecting residual/recurrent squamous cell carcinoma of the head and neck.

Purpose: The use of positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) to detect residual/recurrent squamous cell carcinoma of the head and neck has been tested only in small groups of patients. Our purpose, therefore, was to evaluate the ability of this technique to detect the presence of tumor at both primary and nodal sites in a large cohort of patients.

Methods: All patients referred for PET scanning over a 2.

Spontaneous intracranial hypotension resulting in stupor caused by diencephalic compression.

A 51-year-old man had a 4-month history of progressive headache and gradual onset of somnolence. MRI suggested spontaneous intracranial hypotension (SIH) with diencephalic compression, but he did not improve after three epidural blood patches. He became alert following intrathecal saline infusion that normalized his CSF pressure.

Absence of the abducens nerve in Duane syndrome verified by magnetic resonance imaging.

Purpose: To demonstrate that currently available magnetic resonance imaging techniques may verify the absence of the abducens nerve in Duane syndrome.

Methods: We performed magnetic resonance imaging in a 36-year-old woman with left Duane syndrome, type 1, using spoiled gradient recalled acquisition in the steady state to obtain high-resolution T1-weighted images through the abducens nerve in its subarachnoid segment. Scans were obtained in the axial plane from the medulla to the midbrain and then reformatted along the plane of the abducens nerve.

Neuroradiology workstation reading in an inter-hospital environment: a nineteen month study.

Two workstations (WS) each with two, 2500 line display monitors were installed in the in-patient and the out-patient neuroradiology reading areas for inter-hospital workstation readings. These WSs are part of the display component of a hospital-integrated picture archiving and communication system (PACS). Direct digital neuro images from 10 CT and MR scanners located at various buildings from two medical centers are first transmitted to the PACS database and then distributed to these two WSs automatically.

Diabetes insipidus from sarcoidosis confined to the posterior pituitary.

A young white man with new-onset central diabetes insipidus was discovered to have a posterior pituitary mass on magnetic resonance imaging. No other radiological abnormalities were noted in the anterior pituitary, infundibulum or hypothalamus. No other endocrinopathies were present: laboratory investigations showed normal basal concentrations of anterior pituitary hormones, including prolactin.

Volume MRI and MRSI techniques for the quantitation of treatment response in brain tumors: presentation of a detailed case study.

Patients with primary brain tumors may be considered for several different treatments during the course of their disease. Assessments of disease progression and response to therapy are typically performed by visual interpretation of serial MRI examinations. Although such examinations provide useful morphologic information, they are unable to reliably distinguish active tumor from radiation necrosis.

Serial proton magnetic resonance spectroscopy imaging of glioblastoma multiforme after brachytherapy.

The utility of three-dimensional (3-D) proton magnetic resonance spectroscopy (1H-MRS) imaging for detecting metabolic changes after brain tumor therapy was assessed in a serial study of 58 total examinations of 12 patients with glioblastoma multiforme (GBM) who received brachytherapy. Individual proton spectra from the 3-D array of spectra encompassing the lesion showed dramatic differences in spectral patterns indicative of radiation necrosis, recurrent or residual tumor, or normal brain. The 1H-MRS imaging data demonstrated significant differences between suspected residual or recurrent tumor and contrast-enhancing radiation-induced necrosis.

High resolution T2-weighted imaging of the human brain using surface coils and an analytical reception profile correction.

High spatial resolution T2-weighted MR images of the human brain were obtained at 1.5 T. An optimized fast spin-echo (FSE) sequence and 1.

Imaging of otolaryngologic manifestations of HIV infection.

Patients infected with HIV have severely depressed immune function and are therefore vulnerable to many infectious and neoplastic processes. Head and neck manifestations initially were reported in approximately 40% of patients with AIDS, but in the course of HIV infection and progression to full-blown AIDS, it is now recognized that most patients have abnormalities on head and neck examination at some point in their disease. These manifestations range from relatively benign lymphoid hypertrophy or candidal mucositis to life-threatening fungal infections and high-grade lymphomas.

Alignment of volume MR images and high resolution [18F]fluorodeoxyglucose PET images for the evaluation of patients with brain tumors.

Purpose: The goal of the study was to investigate the use of automated registration techniques for interpretation of volume MR and high resolution FDG-PET images that were obtained from patients with brain tumors.

Method: Twenty-one patients with brain tumors were studied on one or more occasions using MRI and high resolution FDG-PET. The data were aligned using automated volume- and surface-matching algorithms.

High-resolution surface-coil MR of cortical lesions in medically refractory epilepsy: a prospective study.

Purpose: To determine the role of surface-coil MR imaging in evaluating medically refractory neocortical partial epilepsy.

Methods: A prospective study of 25 patients with medically refractory neocortical partial epilepsy was performed. Head- and surface-coil images were reviewed by two neuroradiologists to determine the clarity with which cortical lesions were depicted.

Origins of breath nitric oxide in humans.

Study Objectives: Nitric oxide (NO) exists in the human breath, but little is known about its site of origin or enzyme source. The aims of this study were to locate the main site of NO release into human breath and to decide whether the inducible isoform of NO synthase (iNOS) and nasal bacteria contribute to breath NO.

Design: Using a chemiluminescence assay, NO levels were measured in air exhaled from the nose, mouth, trachea, and distal airway.

Reduced caliber of the internal carotid artery: a normal finding with ipsilateral absence or hypoplasia of the A1 segment.

Purpose: To determine whether a relationship exists between normal variations in anatomy of the circle of Willis and the size of the internal carotid arteries (ICA).

Methods: MR angiograms and axial MR images of the brains of 104 patients were reviewed. Included were 10 patients with unilateral absence of the A1 segment of the anterior cerebral artery, 10 with hypoplasia of one A1 segment, 28 with asymmetric A1 segments, nine with isolated unilateral fetal origin of the posterior cerebral artery, and 47 with balanced circulation.

Central intraluminal saturation stripe on MR angiograms of curved vessels: simulation, phantom, and clinical analysis.

Purpose: To investigate the appearance of reduced signal intensity in the center of blood vessels on magnetic resonance (MR) angiograms that can mimic intraluminal thrombus.

Materials And Methods: Simulations and phantom studies were performed to analyze MR angiogram appearance distal to a pronounced curve.

Results: Saturation effects substantially lower the signal strength in the center of the vessel relative to that at the vessel periphery.

Slow-flow vascular malformations of the pons: capillary telangiectasias?

Purpose: To report clinical and MR features that suggest telangiectatic vascular malformations of the pons:

Methods: The MR scans and clinical data of 12 patients demonstrating an enhancing pontine lesion with minimal or no signal abnormality on T2-weighted images were reviewed. None of the patients underwent angiography or biopsy. Follow-up scans, available for all patients between 3 weeks and 40 months (range, 11.