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At least 883 records · Page 49Linked to original sources
PubMed1998

Neuroimaging appearance of pituitary abscess complicated with close inflammatory lesions--case report.

A 13-year-old girl with a pituitary abscess complained of continuous headache and bitemporal hemianopsia after a common cold. However, she had no inflammatory reactions on admission. Computed tomography showed a low-density sellar mass lesion extending to the suprasellar cistern with a peripheral low-density area, and ring enhancement of the capsule with a particularly thick region. Magnetic resonance imaging showed the mass lesion as a low- and high-intensity area on the T1- and T2-weighted images, respectively. The iso-intense rim of the lesion and the left frontal mass lesion adjacent to the capsule were enhanced by gadolinium-diethylenetriaminepenta-acetic acid. Magnetic resonance imaging also indicated only mild sphenoidal sinusitis which may be representative of the inflammatory process. Careful assessments of neuroimaging findings and preceding trivial inflammatory signs are necessary for the correct diagnosis of a pituitary abscess.

Abscess↗
PubMed1998

Clinical and neuroimaging features of Chiari type I malformations with and without associated syringomyelia.

The clinical and neuroimaging characteristics of 22 consecutive patients with Chiari type I malformations were evaluated to investigate the pathogenesis of syrinx formation. All patients underwent magnetic resonance imaging and x-ray tomography before surgery. The electric manometric Queckenstedt test was performed on 16 patients pre- and postoperatively. Syringomyelia was present in 17 patients and absent in five patients. All patients without syringomyelia suffered from foramen magnum compression syndrome, with a wider basal angle, more acute clivo-axial angle, shorter clivus, and more prominent tonsillar ectopia than patients with syringomyelia. Low brain stem position, basilar impression, and beaking of the cervicomedullary junction were also more prominent in patients without syringomyelia. Marked to complete block with the neck in flexed position by Queckenstedt test was present in all patients except one. Patients with Chiari malformation not associated with syringomyelia have more pronounced compression of the brain stem at the foramen magnum. Therefore, despite a block of the cerebrospinal fluid pathway at the foramen magnum, syrinx formation may be prevented by severe compression.

Adolescent↗
PubMed2001

Serial neuroimaging of a growing thrombosed giant aneurysm of the distal anterior cerebral artery--case report.

An 81-year-old female presented with a giant aneurysm of the distal anterior cerebral artery (A3) which grew from a small saccular aneurysm to a huge aneurysm within 36 months before manifesting as a mass lesion. The thrombosed portion of the aneurysm showed growth, whereas the aneurysmal cavity did not change in size. Computed tomography and magnetic resonance imaging showed new bleeding in the thrombosed portion. Hemorrhage into the thrombus and/or aneurysmal wall might have caused the aneurysmal growth. She refused surgery and was discharged with no deficits. Distal anterior cerebral artery aneurysm which shows neuroimaging signs of growth requires regular follow up as such lesions may become giant before manifesting clinical symptoms.

Aged↗
PubMed2007

Neuroimaging strategies for three types of Horner syndrome with emphasis on anatomic location.

OBJECTIVE: The purposes of this study were to review the anatomy of the oculosympathetic pathway, to describe the clinical characteristics of the three types of Horner syndrome, and to illustrate underlying pathologic features with an emphasis on neuroimaging strategies based on three symptom complexes. CONCLUSION: Horner syndrome results from interruption of the oculosympathetic pathway and is usually associated with unique clinical features classified into central, preganglionic, and postganglionic types according to the anatomic location of the underlying pathologic process.

Adult↗
PubMed1988

Neuroimaging of scuba diving injuries to the CNS.

Diving accidents related to barotrauma constitute a unique subset of ischemic insults to the CNS. Victims may demonstrate components of arterial gas embolism, which has a propensity for cerebral involvement, and/or decompression sickness, with primarily spinal cord involvement. Fourteen patients with diving-related barotrauma were studied with MR imaging of the brain and spinal cord and with CT of the brain. In four patients with presumed cerebral gas embolism, cranial MR was abnormal in three patients while CT was abnormal in only one. Twelve patients had decompression sickness and spinal cord symptoms. MR documented spinal cord abnormalities in three patients. However, scans obtained early in our study were frequently limited by technical constraints. MR of the brain is more sensitive than conventional CT scanning techniques in detecting and characterizing foci of cerebral ischemia caused by embolic barotrauma to the CNS. Although spinal MR may be less successful in the localization of spinal cord lesions related to decompression sickness, these lesions were previously undetectable by other neuroimaging methods.

Adolescent↗
PubMed1996

Neuroimaging findings in patients on immunosuppressive therapy: experience with tacrolimus toxicity.

OBJECTIVE: The purpose of this study is to describe the neuroimaging (CT and MR imaging) findings in liver transplant patients who develop severe neurologic side effects during immunosuppressive therapy with tacrolimus and to correlate these findings with clinical signs and tacrolimus levels in blood. SUBJECTS AND METHODS: Brain CT and/or MR imaging was performed on six patients who developed neurologic symptoms while receiving tacrolimus in the post-transplant period. All patients were evaluated by the neurology staff, and imaging studies were independently interpreted by three neuroradiologists. Trough tacrolimus levels in blood were measured with the IMX immunoassay and were correlated with neurologic symptoms and imaging findings. RESULTS: Imaging abnormalities were observed in five of six patients during the course of their neurologic illnesses. For each patient, neurologic symptoms began when the tacrolimus level in blood was at a peak, exceeding the therapeutic limit in all but one case. In five patients, neurologic symptoms eventually resolved after the tacrolimus dose was reduced or after the drug was stopped. Multifocal low attenuation of white matter was the predominant finding seen on CT images, and matching hyperintense white matter foci were observed on long-TR MR images. In three patients, clinical recovery was accompanied by reversal of the white matter abnormalities seen on CT and MR images. CONCLUSION: Immunosuppressive therapy with tacrolimus may produce neurologic side effects that are associated with brain CT and MR imaging abnormalities. Resolution of symptoms and reversal of imaging findings occur when the tacrolimus dose is reduced.

Adult↗
PubMed1998

CNS infections with free-living amebas: neuroimaging findings.

OBJECTIVE: The purpose of this report is to describe the clinical history, treatment, pathology, and imaging in two cases of rare CNS infection caused by free-living amebas. The Naegleria fowleri and Acanthamoeba species cause primary amebic meningoencephalitis and granulomatous amebic encephalitis, respectively. We describe the neuroimaging findings of a case involving a nonspecific cerebral edema pattern in primary amebic meningoencephalitis and a case involving focal enhancing lesions in granulomatous amebic encephalitis. CONCLUSION: Primary amebic meningoencephalitis and granulomatous amebic encephalitis have a grave prognosis and, although rare, should be considered in the differential diagnosis for patients who present with appropriate histories and imaging findings, including nonspecific brain edema on CT in primary amebic meningoencephalitis and focal punctate enhancing lesions in the posterior cranial fossa on T1-weighted MR imaging in granulomatous amebic encephalitis.

Acanthamoeba↗
PubMed2002

Cerebrovascular disease in HIV-infected pediatric patients: neuroimaging findings.

OBJECTIVE: The goal of our study was to report on the prevalence and the neuroradiologic manifestations of cerebrovascular complications in children infected with HIV. We also elucidate the types of vascular involvement, identify their anatomic distribution, and discuss possible causes. MATERIALS AND METHODS: We conducted a retrospective study of 567 patients (age range, 1 month-29 years; median age, 5.47 years) who acquired HIV as children. Of these, 426 patients (75%) were evaluated with neuroimaging studies. We reviewed these studies to identify the cerebrovascular abnormalities and classify them by type, anatomic location, and shape. RESULTS: Eleven children (2.6%) were found to have cerebrovascular lesions. Only one had focal neurologic symptoms at the time of diagnosis. Twenty-six aneurysms were found in seven patients, and 27 infarctions were found in eight patients. In four of the patients with infarctions, fusiform aneurysms of the cerebral arteries were also identified. Most patients had advanced HIV disease. Nine of the 11 patients were infected by a vertical transmission route or during blood transfusion early in the neonatal period. In this group of patients, the diagnosis of cerebrovascular disease was made earlier (mean age at diagnosis, 8.2 years) than in the two patients who were infected later in life (mean age at diagnosis, 14.9 years). CONCLUSION: HIV-infected children have an increased incidence of cerebrovascular disease that is associated with severe immune suppression and with vertically acquired HIV infection or exposure to the virus in the neonatal period. Despite extensive lesions, most children in our study were asymptomatic. Screening with MR imaging should be considered for high-risk children and is advisable when evidence of neurologic symptoms or neurocognitive dysfunction is noted.

AIDS Arteritis, Central Nervous System↗
PubMed2003

Neuroimaging features of heroin inhalation toxicity: "chasing the dragon".

OBJECTIVE: Our objective was to illustrate the dramatic neuroimaging findings of toxic leukoencephalopathy caused by heroin vapor inhalation. CONCLUSION: Symmetric abnormality involving the cerebellar white matter and posterior limb of the internal capsule is characteristic of heroin vapor inhalation toxicity, although involvement may be more extensive, depending on the severity of the condition. MR imaging and CT appear to be essential for making this diagnosis because clinical history is often unreliable and findings at physical examination are nonspecific.

Administration, Inhalation↗
PubMed1996

Diabetes with the 3243 mitochondrial tRNALeu(UUR) mutation. Characteristic neuroimaging findings.

OBJECTIVE: To investigate the basis of central nervous system dysfunction in diabetes associated with the 3243 mitochondrial tRNA mutation, we studied neuroimaging findings in patients with this disease. RESEARCH DESIGN AND METHODS: We screened 205 diabetic patients. Those patients who had the 3243 mutation in leukocytes or muscle were enrolled. All the subjects underwent computed tomography (CT), magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and N-isopropyl-p-[123I]iodoamphetamine ([123I]IMP) single-photon emission computed tomography (SPECT) of the brain. RESULTS: None of the nine subjects with the 3243 mutation had the typical clinical picture of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes, and none had neurological focal signs. CT or MRI revealed diffuse brain atrophy in three patients (33%) and cerebellar atrophy in one (11%). Abnormal high intensity areas were observed on MRI in five patients (56%). The overall prevalence of brain abnormalities was 56% (5 of 9) on CT and 78% (7 of 9) on MRI scans. MRA revealed no stenotic lesions. SPECT showed reduced accumulation of [123I]IMP in the right or left parieto-occipital region in eight patients (89%). CONCLUSIONS: Reduced accumulation of [123I]IMP in the parieto-occipital cortex was found in a high proportion of our subjects on SPECT. This imaging finding might be characteristic of diabetes associated with the 3243 mitochondrial tRNA mutation and may be a sign of latent central nervous system dysfunction.

Adult↗
PubMedDate not supplied

The relationship between neuropsychological function and brain damage detected by neuroimaging after closed head injury.

Studies relating neuropsychology and structural neuroimaging after closed head injury are reviewed. Particular attention is given to the question of the relative contribution of focal and diffuse damage to neuropsychological impairment. The evidence currently available emphasizes the importance of diffuse damage in closed head injury. Diffuse damage is not equally distributed in the brain, and the review suggests three axes that are relevant for neuropsychological function: (1) damage may be unilateral or bilateral, (2) damage is characteristically greater in anterior regions than posterior regions, and (3) damage shows a centripetal gradient. A large gap remains between the emergent generalizations concerning head injury and reliable neuropsychological interpretation of scans from individual patients.

Brain↗
PubMed2003

Falcotentorial meningiomas: clinical, neuroimaging, and surgical features in six patients.

OBJECT: Meningiomas arising from the falcotentorial junction are rare. As a result, their clinical presentation and surgical management are not well described. During the past 3 years, the authors have treated six patients with falcotentorial meningiomas. METHODS: Most patients presented with symptoms related to raised intracranial pressure, including headaches, papilledema, and visual and gait disturbances. Magnetic resonance imaging revealed a smooth, oval, or round mass, which was typically homogeneously enhancing. Angiography was useful in evaluating arterial supply for embolization, when possible, and determining the status of venous collateral supply and sinus patency. The authors detail the surgical technique used in all six patients. Postoperatively, patients experienced transient cortical blindness, which in all cases spontaneously resolved during the course of several days to weeks. They provide a comprehensive description of the presentation and surgical management of falcotentorial meningiomas. CONCLUSIONS: An excellent outcome can be expected when surgery is predicated on detailed preoperative neuroimaging and knowledge of the nuances of the surgical technique.

Diagnostic Imaging↗
PubMed2001

Cerebrospinal fluid immunocytochemical analysis and neuroimaging in the diagnosis of primary leptomeningeal melanoma. Case report.

A 20-year-old man presented with slowly progressing symptoms indicative of increased intracranial pressure. Two weeks later he underwent surgery for placement of a ventriculoperitoneal shunt. Cytological examination of the patient's cerebrospinal fluid (CSF) revealed atypical cells that contained no detectable melanin deposits, but proved to be immunocytochemically positive for monoclonal antibodies to melanocytic cells (HMB-45) and S-100 protein. Dermatological and ophthalmological examinations failed to demonstrate any abnormalities. On the basis of these findings, a diagnosis of primary leptomeningeal melanoma was made. Gadolinium-enhanced magnetic resonance (MR) images of the brain and spinal regions obtained 2 months after admission demonstrated typical widespread leptomeningeal enhancement. Results of technetium-99m-hexakis (2-methoxyisobutyl isonitrile) single-photon emission computerized tomography (99mTc-MIBI SPECT) scanning revealed intense uptake of the isotope in the leptomeningeal regions and some cisterns. The patient's condition progressively worsened and he died 5 months after admission. The diagnosis was confirmed at autopsy. Immunocytochemical analysis of CSF performed using HMB-45 and S-100 protein antibodies is important for the diagnosis of leptomeningeal melanoma because of the test's simplicity, high specificity, and sensitivity. Gadolinium-enhanced MR imaging is used to demonstrate the extent of the leptomeningeal melanoma. An additional and supplemental neuroimaging modality, 99mTc-MIBI SPECT scanning has good potential for the detection and diagnosis of leptomeningeal melanoma.

Adult↗
PubMed2001

Neuroimaging of cerebellar liponeurocytoma. Case report.

Cerebellar liponeurocytoma is a newly recognized, rare clinicopathological entity. It manifests with posterior fossa symptoms in adults and is characterized histopathologically by advanced neuronal and focal lipomatous differentiation with a low level of mitotic activity. The authors analyzed the computerized tomography (CT) and magnetic resonance (MR) imaging findings in two patients with histopathologically proven cerebellar liponeurocytomas and review the literature. Cerebellar liponeurocytoma may be suspected on the basis of neuroimaging findings that demonstrate an intraaxial neoplasm with the propensity for exophytic growth into the adjacent subarachnoid spaces. On CT scans, the tumor commonly presents as a hypointense mass with intermingled areas exhibiting the attenuation values of fatty tissue. On T1-weighted MR images, the tumor is hypointense with scattered foci of hyperintense signal and displays moderate contrast enhancement. On T1-weighted MR images, the tumor is slightly hyperintense to cortex, and edema is usually absent. Areas of fat density as assessed on CT scans and of T1 hyperintensity seen on MR images help to distinguish this rare neoplasm from the more common adult medulloblastomas or ependymomas. The available follow-up data indicate a favorable clinical prognosis; therefore, knowledge and precise characterization of this tumor is important to avoid unnecessary adjuvant radio- or chemotherapy.

Adult↗
PubMed2003

Clinical and neuroimaging characteristics of hydrocephalus associated with vestibular schwannoma.

OBJECT: The clinical and neuroimaging characteristics of hydrocephalus associated with vestibular schwannoma were retrospectively analyzed to improve the perioperative management of the circulation of cerebrospinal fluid. METHODS: A retrospective analysis was performed in 236 patients with unilateral vestibular schwannomas. The patients' ages ranged from 17 to 83 years (mean 53.6 +/- 13.2 years), and the diameters of the tumors the patients harbored ranged from 5 to 60 mm (mean 30.5 +/- 12.7 mm). Hydrocephalus was present before tumor resection in 33 patients (14%) and in six of these patients focal dilation of the sylvian fissures was noted. There was a significant correlation between the incidence of hydrocephalus and tumor size. The incidence of preoperative hydrocephalus among elderly patients (> or = 65 years of age) was 28.6% and that among younger patients (< 65 years of age) was 10.8%. Tumors in elderly patients with hydrocephalus (mean tumor diameter 32.8 +/- 11.7 mm; 12 patients) were significantly smaller than those in younger patients (mean tumor diameter 41.7 +/- 10.9 mm; 21 patients). Among patients with tumors smaller than 30 mm (114 patients), the incidence of hydrocephalus in elderly patients (25%) was 12-fold higher than that in younger patients (2.1%). Six patients with hydrocephalus who had focal dilation of the sylvian fissures were significantly older than 27 patients with hydrocephalus in whom there was no focal dilation. The dilated sylvian fissures collapsed in two patients spontaneously after tumor resection and in the other four patients after shunt placement. CONCLUSIONS: The incidence of associated hydrocephalus is higher in older patients. Communicating hydrocephalus tends to occur in elderly patients. Enlargement of the ventricles with focal dilation of the sylvian fissures should not be misinterpreted as physiological brain atrophy.

Adolescent↗
PubMed2003

Evolution of a cochlear schwannoma on clinical and neuroimaging studies. Case report.

The authors report on a patient with a rare schwannoma that arose from the cochlear division of the vestibulocochlear nerve. Distinctively, the lesion appeared to arise from the cochlea itself and was monitored with clinical and neuroimaging studies for 12 years before it was diagnosed and treated. The atypical occurrence of schwannomas of the vestibulocochlear nerve originating in the inner ear structures underscores the high level of clinical suspicion required for the diagnosis of these lesions in patients presenting with persistent auditory and vestibular symptoms.

Cochlea↗
PubMed2004

Preoperative neuroimaging findings as a predictor of the surgical plane of cleavage: prospective study of 100 consecutive cases of intracranial meningioma.

OBJECT: To understand the cause and prevention of postoperative ischemic and/or venous parenchymal infarcts after intracranial meningioma resection, the authors describe the value of neuroimaging in predicting the surgical plane of cleavage. METHODS: A prospective study of 100 meningiomas was performed, in which tumor size, absence or presence of peritumoral edema, tumor-parenchyma interface, and types of arterial vascularization (that is, dural-meningeal, pial-cortical, or mixed) were correlated with the type of dissection plane (extrapial, subpial, or mixed) encountered at surgery. A direct correlation was found between the tumor size identified on T1-weighted magnetic resonance (MR) imaging sequences and the degree of subpial (nonextrapial) surgical plane of cleavage (p < 0.00001). A similar correlation was found with the grade of peritumoral edema identified on preoperative computerized tomography (CT) scanning (p < 0.0001) or T2-weighted MR imaging sequences (p < 0.00001) and tumor pial vascularization as seen on angiography (p < 0.0001). Nevertheless, the tumor-parenchyma interface on preoperative T2-weighted MR imaging sequences was not predictive of the surgical plane (p > 0.5). The worst clinical outcome was found in the tumors located in eloquent areas and in which a subpial plane was encountered at surgery (p = 0.03). CONCLUSIONS: Peritumoral edema on preoperative CT and MR studies and tumor pial vascularization as seen on selective angiography can be used to predict the surgical plane of cleavage in meningiomas. The association between tumor size and a subpial surgical plane may be explained by a more pial vascularization seen on angiography. Meningiomas with a location in eloquent cortex and a subpial dissection plane should be considered a high-risk group.

Adult↗
PubMed2005

Neuroimaging-detected late transient treatment-induced lesions in pediatric patients with brain tumors.

OBJECT: After the resection of brain tumors in pediatric patients, it can be difficult to differentiate recurrent tumor from treatment effects. Although late-delayed reactions are thought to be permanent, in this study the authors sought to characterize transient brain lesions (TBLs) in the late-delayed period that completely resolved without imaging or neurological sequelae. METHODS: In a retrospective review of an institutional neuroimaging brain tumor database, 11 patients were identified who met the imaging criteria (transient T2-weighted hyperintense enhancing lesions outside of the tumor bed, which occurred after radiation and/or chemotherapy) and had undergone three-dimensional dosimetry; their radiographic, clinical, and radiation-dosimetry results were analyzed. In the 11 patients who had been treated with multiple protocols 17 loci of abnormality, including 43 discrete, asymptomatic TBLs, were detected. The median TBL diameter was 1 cm or smaller, without mass effect or necrosis, and occurred 10 months after radiation therapy, 11 months after chemotherapy, resolved by 3 months, and occurred within the high-dose radiation treatment volume (median 55.8 Gy). The findings from extended follow up revealed the development of additional permanent complications of radiation therapy within the radiation port in five of the 11 patients. CONCLUSIONS: A benign form of treatment-induced brain injury in children, TBLs should be treated using short-interval follow up. When these lesions are identified as a result of their characteristic imaging features, location, and temporal course, TBLs may be clearly distinguished from recurrent tumor or radiation necrosis and do not require biopsy. Further studies are needed to determine whether patients with TBLs are at an increased risk of developing more severe treatment-related brain injury.

Antineoplastic Combined Chemotherapy Protocols↗