CT demonstration of dacryolithiasis complicated by dacryocystitis.

Cross-sectional imaging has demonstrated an increasing role in the evaluation of the orbits and the periorbital structures. The case presented in this article demonstrates the rare finding of a dacryolith by CT. To our knowledge, little has been reported on cross-sectional imaging characteristics of this entity in the recent radiologic literature.

The vestibulocochlear nerve.

The eighth nerve provides sensory connection for balance and sound. Our ability to evaluate its morphology and pathology with magnetic resonance imaging (MRI) has been substantially improved over the past 20 years. This article reviews the relevant anatomy of the eighth nerve.

Lacunar infarct during pallidotomy: case report.

A symptomatic lacunar infarct is an unusual complication which may develop during stereotactically guided pallidotomy using radiofrequency thermoablation. We describe a 54-year-old man with Parkinson's disease involving predominantly the right side, progressively deteriorating under medical management. He underwent stereotactically guided radiofrequency thermoablation of the posteroventral globus pallidus interna.

Interregional variation of longitudinal relaxation rates in human brain at 3.0 T: relation to estimated iron and water contents.

In a study of interregional variation of the longitudinal relaxation rate (R(1)) in human brain at 3 T, R(1) maps were acquired from 12 healthy adults using a multi-slice implementation of the T one by multiple readout pulses (TOMROP) sequence. Mean R(1) values were obtained from the prefrontal cortex (0.567 +/- 0.

MR of CNS sarcoidosis: correlation of imaging features to clinical symptoms and response to treatment.

Background And Purpose: Sarcoidosis is an idiopathic systemic granulomatous disease, recognized in a patient when clinical and radiologic findings are confirmed by histopathologic analysis. The objective was to identify a relationship between MR imaging and clinical findings in CNS sarcoidosis.

Methods: The clinical charts of 461 patients with biopsy-proved sarcoidosis were reviewed retrospectively.

MR imaging of human brain at 3.0 T: preliminary report on transverse relaxation rates and relation to estimated iron content.

Purpose: To determine the transverse relaxation rates R2 and R2' from several gray matter regions and from frontal cortical white matter in healthy human brains in vivo and to determine the relationship between relaxation rates and iron concentration [Fe].

Materials And Methods: Six healthy adults aged 19-42 years underwent thin-section gradient-echo sampling of free induction decay and echo magnetic resonance (MR) imaging at 3.0 T.

Duropleural fistula manifested as a large pleural transudate: an unusual complication of transthoracic diskectomy.

A 52-year-old patient presented with large symptomatic transudative pleural effusion 4 months following T8 to T9 transthoracic diskectomy. Anterior approach diskectomy has replaced the traditional laminectomy for treating symptomatic centrally herniated and calcified thoracic disks. We describe in this report the first case of a large cerebrospinal fluid collection in the pleural cavity caused by persistent postoperative duropleural fistula.

Segmentation of acoustic neuromas with magnetic resonance imaging and Eigen image filtering.

Objective: This study aimed to determine whether magnetic resonance imaging with Eigen image filtering can segment acoustic neuromas as a preliminary requirement to the development and validation of a volumetric method of measuring tumor size and growth using Eigen image filtering.

Study Design: This was an observational study.

Setting: The study was performed in an academic, comprehensive multi-specialty group practice.

Bilateral superior ophthalmic vein enlargement associated with diffuse cerebral swelling. Report of 11 cases.

Bilateral superior ophthalmic vein (SOV) enlargement has rarely been shown to occur in patients with septic and aseptic cavernous sinus thrombosis, Graves' disease due to obstruction of the SOV by enlarged extraocular muscles, or carotid-cavernous fistulas caused by retrograde flow. The authors describe 11 patients with bilateral SOV enlargement associated with cerebral swelling as detected by computerized tomography scanning. The bilaterally enlarged SOVs returned to a normal size following resolution of cerebral swelling and elevated intracranial pressure.

Cystic papillary adenocarcinoma of the submandibular gland in a child.

A 12-year-old boy reported that a mass in his left jaw had been growing slowly for 8 months. Axial and coronal contrast-enhanced spiral CT showed a 5-cm cystic mass within an enhancing, mildly enlarged submandibular gland. Excisional biopsy revealed a cystic papillary adenocarcinoma of the left submandibular gland, very rare in children.

Efficacy of gadolinium administration in magnetic resonance imaging screening of patients with complex partial seizures and results of a normal neurologic examination.

Rationale And Objectives: Magnetic resonance imaging has become a standard screening tool in the evaluation of patients with complex partial seizures. This study prospectively addresses the efficacy, if any, of routinely adding gadolinium-enhanced images to routine T2-weighted images in patients with a normal neurologic examination.

Methods: One hundred consecutive patients with electroencephalogram and clinical evidence of complex partial seizures and no other neurologic abnormalities were examined prospectively with axial and coronal T2-weighted spin-echo images, followed by axial and coronal gadolinium-enhanced T1-weighted scans.

MR demonstration of Wegener granulomatosis of the infundibulum, a cause of diabetes insipidus.

We report a case of Wegener granulomatosis causing hyperprolactinemia followed by central diabetes insipidus. The initial T1-weighted MR image showed an isointense heterogeneous sellar mass. After the onset of diabetes insipidus, repeat sagittal and postcontrast T1-weighted images showed marked infundibular thickening, enlargement of the sellar mass, and enhancement of both the infundibulum and hypothalamus.

Normal imaging anatomy of the suprasellar cistern and floor of the third ventricle.

This article discusses the gross, functional, and imaging anatomy of the suprasellar cistern and its contents as well as the structures that form its borders, among the most important being the floor of the third ventricle and associated structures. Specific structures discussed include the optic chiasm and optic tracts, the anterior third ventricle, the tuber cinereum, the pituitary stalk (infundibulum), the choroidal fissure, the lamina terminalis, the gyrus rectus, the uncus, and the cerebral peduncles.

Persistent trigeminal artery detected with standard MRI.

The trigeminal artery is the most common of the primitive carotid-basilar anastomoses to persist into adulthood. Prior to the introduction of MRI, the diagnosis of persistent trigeminal artery (PTA) could only be made at cerebral angiography. This study compares angiography and standard brain MRI in 11 cases of PTA.

Analysis of the evolution of focal cerebral ischemia in the rat using the eigenimage filter.

The eigenimage filter was used to evaluate the results of a MRI study of cerebral ischemia in a rat model. This linear filter segments a desired feature in an image sequence from other features which may interfere with its observation. The animals were imaged temporally, after occlusion of the middle cerebral artery, to investigate the evolution of the ischemic process.

Anomalous rib presenting as cervical myelopathy: a previously unreported variant of Klippel-Feil syndrome. Case report.

A patient is reported with an anomalous rib that caused compression of the cervical spinal cord and presented with cervical myelopathy. This appears to be the first reported instance of this particular anomaly. The clinicoanatomical aspects of this case are discussed.

MR of hemorrhagic acoustic neuromas.

The magnetic resonance (MR) appearance of hemorrhagic acoustic neuromas has not previously been reported. Four patients with surgically proven acoustic neuromas containing spontaneous hemorrhage were preoperatively evaluated with MR imaging. All patients presented with new onset of symptoms and three had subarachnoid hemorrhage.

The MR appearance of endovascular embolic agents in vitro with clinical correlation.

A spectrum of embolic agents including PVA, avitene, gelfoam, ethanol, IBCA, silicone microspheres, metal and platinum coils, and balloons containing contrast of HEMA were imaged in vitro at 0.3 Tesla using spin echo, gradient echo, and inversion recovery sequences. Signal intensities associated with these agents and changes created by addition of blood are presented.

Current status of magnetic resonance imaging of the orbit.

MR plays an important role in evaluating pathologic conditions that affect the orbit. MR appears to be superior to ultrasound and computed tomography in evaluation of intraocular tumors and fluid collections. In evaluation of noncalcified intraorbital tumors, MR can provide more information regarding orbital apex involvement and intracranial extension.

Magnetic resonance demonstration of vertebral artery dissection. Report of two cases.

Vertebral artery dissection may be spontaneous or related to some traumatic event. Diagnosis has usually been made by angiography, an invasive procedure with certain well-known risks. The authors describe the magnetic resonance (MR) appearance (both on conventional spin-echo and on gradient refocused "flow" sequences) in two patients with vertebral artery dissection confirmed by angiography.

MR imaging of acute subarachnoid hemorrhage.

The MR appearance of acute subarachnoid hemorrhage experimentally produced in Macaca monkeys and observed in patients with clinically documented acute subarachnoid hemorrhage is presented. Subarachnoid hemorrhages were produced in two Macaca Nemestrema monkeys using the technique of Frazee. CT and MR imaging were performed immediately after the procedure and at frequent intervals up to two week post hemorrhage.

Extracranial lesions of the head and neck: preliminary experience with Gd-DTPA-enhanced MR imaging.

The authors report initial experience with magnetic resonance imaging enhanced with gadolinium diethylenetriaminepentaacetic acid (DTPA) in 27 patients with various extracranial lesions of the head and neck. Unenhanced T1- and T2-weighted images were compared with T1-weighted images obtained 3-30 minutes after Gd-DTPA administration. Overall, compared with precontrast T1- and T2-weighted images, Gd-DTPA improved the visibility of lesions in 11 and five of 27 patients, respectively.

Head and neck lesions: MR-guided aspiration biopsy.

Aspiration biopsy guided with computed tomography (CT) has long been a valuable tool in the evaluation of head and neck disease. The ability to obtain diagnoses without the need for surgery has had a significant effect on patient treatment. Magnetic resonance (MR) imaging is now rapidly replacing CT as the primary imaging study for many head and neck diseases.