Radionuclide shuntogram demonstrating migration of distal ventriculoperitoneal shunt tubing out of the peritoneal cavity.

An 81-year-old man with a history of ventriculoperitoneal (V-P) shunt placement for symptomatic normal pressure hydrocephalus presented with recurrence of confusion and gait disturbance. Radionuclide cisternography demonstrated loculation of In-111 DTPA in the abdominal wall. A soft tissue mass palpated at the location of tracer accumulation was confirmed to be extraperitoneal pooling of fluid at the site of coiling of the distal shunt tip.

Acute and chronic brain injury in United States National Team soccer players.

We designed a study to determine whether chronic encephalopathy occurs in elite, active soccer players resulting from repetitive heading of the soccer ball. Studies have suggested that the cumulative effects of heading a ball can cause a chronic brain syndrome similar to dementia pugilistica, which is seen in professional boxers. Twenty of 25 members of the U.

Positron emission tomography with fluorodeoxyglucose to evaluate tumor response and control after radiation therapy.

Purpose: Following radiation therapy, evaluation of viable tumor can often be difficult with anatomic imaging criteria (tumor size alone). In this study, the utility of biochemical imaging with the glucose analog 2-[F-18]fluoro-2-deoxy-D-glucose and positron emission tomography was investigated in patients treated with radiation therapy.

Methods And Materials: Between 1990 and 1992, 19 patients were studied, including 15 patients with head and neck cancer, (4 oropharynx, 4 sinus, 3 larynx, 2 hypopharynx, 2 oral cavity [one patient], 1 nasopharynx), and 4 patients with breast cancer.

Extracranial head and neck: PET imaging with 2-[F-18]fluoro-2-deoxy-D-glucose and MR imaging correlation.

The aim of this study was to define and quantitate the normal anatomy of the extracranial head and neck with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET). This information was used to study 12 patients with primary squamous cell carcinomas. In all cases, the lymphoid tissue of the Waldeyer ring and the palatine and lingual tonsils could be differentiated from the airway, striated muscle, osseous structures, and salivary glands.

Three-dimensional CT scan reconstruction for the assessment of congenital aural atresia.

Major advances in medical computer graphics workstations have provided the capability to produce high quality three-dimensional image reconstructions from conventional thin-section computerized tomography (CT) scans with the ability to observe the imaged structure from any angle, with views and dimensions that are comparable to actual dissections. We have applied this technique to the temporal bone to assess congenital aural atresia in surgical planning for hearing reconstruction in six patients. The digital information produced by thin-section CT scanning allowed for the re-creation of multiplanar reformatted, shaded surface, and volumetric images.

Fat-suppression failure artifacts simulating pathology on frequency-selective fat-suppression MR images of the head and neck.

Purpose: To describe fat-suppression failure artifacts and to caution against their misinterpretation.

Method: Magnetic-susceptibility artifacts were studied in a phantom model and the results were compared to MR images obtained in clinical cases.

Findings: Artifacts manifested themselves as regions of focal fat-suppression failure and appeared as bright signals without geometric distortions at magnetic-susceptibility interfaces along the static field (z) direction.

Positron emission tomography: a new, precise imaging modality for detection of primary head and neck tumors and assessment of cervical adenopathy.

Positron emission tomography (PET) has been shown to be effective in detecting intracranial malignancies based on cerebral glucose metabolism. To evaluate the ability of PET to detect extracranial head and neck neoplasms and cervical metastases, 16 patients with primary squamous cell carcinomas were examined. All patients received preoperative computerized tomography (CT) and magnetic resonance imaging (MRI) scans and underwent PET evaluation using intravenous 18F-2-fluoro-2-deoxy-D-glucose (FDG).

Magnetic resonance imaging-guided fine needle aspiration for the diagnosis of skull base lesions.

Magnetic resonance imaging (MRI)-guided fine needle aspiration was used to obtain tissue from lesions of the skull base for cytologic diagnoses in 14 patients. Our technique utilized a guiding system to enable three-dimensional orientation in a two-dimensional scan and a high nickel content 22 gauge needle to minimize significantly MRI artifact. Needle access to the skull base was provided through a subzygomatic or retromandibular approach.

MR-guided aspiration cytology in the head and neck at high field strength.

Published reports of magnetic resonance (MR)-guided needle biopsy have involved low- and mid-field-strength systems because of the concern of needle artifact and risk of increased needle torque at higher field strengths. To the authors' knowledge, this is the first report of a high-field-strength (1.5-T) system used to guide aspiration cytology in the head and neck in a patient.

Metastatic head and neck malignancy treated using MRI guided interstitial laser phototherapy: an initial case report.

Interstitial laser phototherapy (ILP) guided by magnetic resonance imaging (MRI) may become an attractive adjunctive modality for the treatment of deep and surgically inaccessible tumors of the head and neck when accurate methods of laser dosimetry and "real-time" monitoring techniques with the MRI are introduced. We recently demonstrated in ex vivo and in vivo models, a linear relationship between levels of laser energies, thermal profiles, MR signal intensity changes, and histopathological tissue damage. Results of treatment in a patient with an unresectable large right jugulodigastric metastatic squamous carcinoma using new approach of MRI guided ILP are now reported.

MR imaging-guided interstitial Nd:YAG laser phototherapy: dosimetry study of acute tissue damage in an in vivo model.

A dosimetry study of acute tissue damage induced by interstitial application of the neodymium-yttrium-aluminum-garnet (Nd:YAG) laser was performed with magnetic resonance (MR) imaging. The MR appearance of the lesion was correlated with gross and histopathologic findings. Seventy-six lesions were induced in rabbit muscle with laser power outputs of 5-20 W and exposure times of 20-600 seconds.

Nonneoplastic enhancing lesions mimicking intracanalicular acoustic neuroma on gadolinium-enhanced MR images.

The authors describe five patients with nonneoplastic lesions of the facial and/or vestibulocochlear nerves that demonstrated focal enhancement within the internal auditory canal on magnetic resonance (MR) images. MR and surgical findings for four patients with unilateral sensorineural hearing loss and one with Ramsay Hunt syndrome were reviewed. Three patients with hearing loss underwent surgical exploration and decompression of the internal auditory canal.

Meckel cave lesions: percutaneous fine-needle-aspiration biopsy cytology.

The authors describe the novel combination of two traditional methods to facilitate diagnosis of Meckel cave lesions, which may otherwise require craniotomy to obtain adequate tissue samples. Fine-needle-aspiration biopsy cytology was performed on tissue obtained with a percutaneous approach via the foramen ovale with use of fluoroscopic guidance and intravenous analgesia during an outpatient procedure. This new application of fine-needle-aspiration biopsy cytology results in decreased patient morbidity and significant cost reduction.

Imaging of the temporal bone.

Computed tomography remains the imaging modality of choice in investigating conductive hearing loss. The improvement of MR imaging surface-coil technology is allowing a number of inflammatory and neoplastic diseases in the temporal bone to be detected more effectively. These two modalities when used correctly will detect many of the soft tissue and bony abnormalities of the temporal bone.

Spontaneous dural carotid-cavernous fistula with central retinal vein occlusion and iris neovascularization.

Spontaneous dural carotid-cavernous fistulas are dural vascular malformations that usually run a benign course. We present a case of a spontaneously occurring dural carotid-cavernous fistula complicated by central retinal vein occlusion and iris neovascularization that led to progressive visual failure.

Interventional magnetic resonance imaging in the head and neck.

Interventional MRI is clearly in its early stages of development. While the value of MR-guided aspiration cytology and MR evaluation of deep electrode implantation in the brain has already been confirmed with human clinical studies, the future of MR-guided interstitial laser therapy remains to be proven. Despite this, as we look ahead into the 1990s and the millennium, it is possible to imagine dedicated MR laser therapy units for combined radiological and surgical outpatient approaches in what may become the operating rooms of the 21st century.

Magnetic resonance imaging of metastatic cervical adenopathy.

Detecting cervical adenopathy is critical in the management of carcinomas in head and neck. CT scanning remains a very effective modality in defining adenopathy. T1-weighted MRI scans are comparable to CT in detecting lymph nodes.

Magnetic resonance imaging of the larynx.

The development of appropriate surface coils has resulted in outstanding depiction of the laryngeal anatomy using MRI. The multiplanar capability of MR allows superior definition of anatomy and tumor extent compared with CT scanning. MR appears to be more effective in detecting cartilage invasion.

Magnetic resonance imaging of the tongue and oropharynx.

In general, MRI produces superior soft tissue detail in evaluating the tongue and oropharynx than does CT. MRI is therefore considered the study of choice in this area. Lack of artifact from dental amalgam and beam hardening artifact from the mandible on MRI also eliminates two major shortcomings of CT in the examination of this area.