Tuberculoma presenting as an en plaque meningioma

1996 ◽  
Vol 85 (4) ◽  
pp. 685-688 ◽  
Author(s):  
Jerry Bauer ◽  
Roger F. Johnson ◽  
Joseph M. Levy ◽  
Donald V. Pojman ◽  
John R. Ruge
Keyword(s):  
Magnetic Resonance ◽  
Computerized Tomography ◽  
Brain Parenchyma ◽  
Magnetic Resonance Images ◽  
Content Type ◽  
Multiple Lesions ◽  
Intracranial Tuberculoma ◽  
The Brain ◽  
Fine Print

✓ Intracranial tuberculomas generally present as either solitary or multiple lesions in the brain parenchyma. They are characterized by a ring-enhancing area on either computerized tomography scans or magnetic resonance images. A case is presented in which an intracranial tuberculoma was dural based and had an appearance similar to an en plaque meningioma.

Convective distribution of macromolecules in the primate brain demonstrated using computerized tomography and magnetic resonance imaging

2003 ◽  
Vol 98 (3) ◽  
pp. 584-590 ◽  
Author(s):  
Tung T. Nguyen ◽  
Yashdip S. Pannu ◽  
Cynthia Sung ◽  
Robert L. Dedrick ◽  
Stuart Walbridge ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Computerized Tomography ◽  
Ct Scanning ◽  
Therapeutic Agents ◽  
Content Type ◽  
Drug Concentrations ◽  
The Brain ◽  
Fine Print

Object. Convection-enhanced delivery (CED), the delivery and distribution of drugs by the slow bulk movement of fluid in the extracellular space, allows delivery of therapeutic agents to large volumes of the brain at relatively uniform concentrations. This mode of drug delivery offers great potential for the treatment of many neurological disorders, including brain tumors, neurodegenerative diseases, and seizure disorders. An analysis of the treatment efficacy and toxicity of this approach requires confirmation that the infusion is distributed to the targeted region and that the drug concentrations are in the therapeutic range. Methods. To confirm accurate delivery of therapeutic agents during CED and to monitor the extent of infusion in real time, albumin-linked surrogate tracers that are visible on images obtained using noninvasive techniques (iopanoic acid [IPA] for computerized tomography [CT] and Gd—diethylenetriamine pentaacetic acid for magnetic resonance [MR] imaging) were developed and investigated for their usefulness as surrogate tracers during convective distribution of a macromolecule. The authors infused albumin-linked tracers into the cerebral hemispheres of monkeys and measured the volumes of distribution by using CT and MR imaging. The distribution volumes measured by imaging were compared with tissue volumes measured using quantitative autoradiography with [14C]bovine serum albumin coinfused with the surrogate tracer. For in vivo determination of tracer concentration, the authors examined the correlation between the concentration of the tracer in brain homogenate standards and CT Hounsfield units. They also investigated the long-term effects of the surrogate tracer for CT scanning, IPA-albumin, on animal behavior, the histological characteristics of the tissue, and parenchymal toxicity after cerebral infusion. Conclusions. Distribution of a macromolecule to clinically significant volumes in the brain is possible using convection. The spatial dimensions of the tissue distribution can be accurately defined in vivo during infusion by using surrogate tracers and conventional imaging techniques, and it is expected that it will be possible to determine local concentrations of surrogate tracers in voxels of tissue in vivo by using CT scanning. Use of imaging surrogate tracers is a practical, safe, and essential tool for establishing treatment volumes during high-flow interstitial microinfusion of the central nervous system.

Diagnostic value of 201Tl—single-photon emission computerized tomography studies in cases of posterior fossa hemangioblastomas

2001 ◽  
Vol 95 (2) ◽  
pp. 292-297 ◽  
Author(s):  
Takeo Kondo ◽  
Toshihiro Kumabe ◽  
Shin Maruoka ◽  
Takashi Yoshimoto
Keyword(s):  
Computerized Tomography ◽  
Posterior Fossa ◽  
Single Photon ◽  
Photon Emission ◽  
Magnetic Resonance Images ◽  
Thallium 201 ◽  
Homologous Region ◽  
Single Photon Emission ◽  
Content Type ◽  
Fine Print

Object. The 201Tl uptake index was evaluated for its usefulness in formulating a diagnosis of hemangioblastoma. Thallium-201—single-photon emission computerized tomography (SPECT) studies were performed in nine patients harboring hemangioblastomas in the posterior fossa and in five patients (six lesions) with gliomas in the posterior fossa. Methods. The 201Tl uptake index was defined as the ratio of mean counts of isotope per pixel in the tumor to mean counts of isotope per pixel in the homologous region of the healthy brain. The 201Tl uptake indices of the early image (TlE) and that of the delayed image (TlD) were calculated. The isotope retention index (RI) was calculated as (TlE − TlD)/TlE. The TlE was 2.7 ± 0.7 in hemangioblastomas and 2.9 ± 1.7 in gliomas (mean ± standard deviation). The TlD was 1.5 ± 0.4 in hemangioblastomas and 2.4 ± 1.6 in gliomas. There were no significant differences between hemangioblastomas and gliomas when TlEs and TlDs were compared. The isotope RI was 0.43 ± 0.07 in hemangioblastomas and 0.15 ± 0.1 in gliomas, showing a significantly higher RI in hemangioblastomas compared with gliomas (p < 0.01). Conclusions. Thallium-201 washout is significantly faster in hemangioblastomas. Hemangioblastoma is biologically benign, but contains a rich capillary network that forms a hypervascular tumor bed. Variations in its appearance on magnetic resonance images may cause difficulties in the differential diagnosis of hemangioblastoma. Thallium-201 SPECT studies can be used to distinguish hemangioblastomas from gliomas in the posterior fossa.

Galenic dural arteriovenous fistula: unusual clinical presentation and successful endovascular therapy

2002 ◽  
Vol 97 (2) ◽  
pp. 467-470 ◽  
Author(s):  
John B. Weigele ◽  
John C. Chaloupka ◽  
Walter S. Lesley
Keyword(s):  
Magnetic Resonance ◽  
Arteriovenous Fistula ◽  
Dural Arteriovenous Fistula ◽  
Clinical Presentation ◽  
Magnetic Resonance Images ◽  
Interstitial Edema ◽  
Content Type ◽  
Clinical Recovery ◽  
Structural Abnormalities ◽  
Fine Print

✓ The authors report a case in which the clinical and neuroimaging findings were initially considered diagnostic of a brainstem glioma. Angiography revealed a deep venous system (galenic) dural arteriovenous fistula causing brainstem interstitial edema. Successful endovascular surgery resulted in complete clinical recovery of the patient and resolution of the structural abnormalities that had been observed on magnetic resonance images. The neuroimaging and therapeutic significance of this case are discussed.

A transparent sheath for endoscopic surgery and its application in surgical evacuation of spontaneous intracerebral hematomas

2000 ◽  
Vol 92 (6) ◽  
pp. 1053-1055 ◽  
Author(s):  
Tetsuhiro Nishihara ◽  
Akira Teraoka ◽  
Akio Morita ◽  
Keisuke Ueki ◽  
Keisuke Takai ◽  
...  
Keyword(s):  
Endoscopic Surgery ◽  
Brain Parenchyma ◽  
Bleeding Point ◽  
Content Type ◽  
Minimal Invasiveness ◽  
Surgical Evacuation ◽  
Endoscopic Evacuation ◽  
Surgical Field ◽  
The Brain ◽  
Fine Print

✓ The authors advocate the use of a transparent sheath for guiding an endoscope, a simple and unique tool for endoscopic surgery, and describe preliminary results of its application in the evacuation of hypertensive intracerebral hematomas. This sheath is a 10-cm-long tube made of clear acrylic plastic, which greatly improves visualization of the surgical field through a 2.7-mm nonangled endoscope inserted within. Between April 1997 and December 1998, the authors performed endoscopic evacuation of intracerebral hematomas by using this sheath inserted into the patients' heads through a burr hole. In nine consecutive cases in which the hematoma was larger than 40 ml in volume, nearly complete evacuation (86–100%) of the lesion was achieved without complication. Excellent visualization of the border between the brain parenchyma and the hematoma facilitated accurate intraoperative orientation, and also allowed easy identification of the bleeding point. Thus, this combination of sheath and endoscope achieves both minimal invasiveness and the maximum extent of hematoma removal with secure hemostasis. This tool will reduce the inherent disadvantage of endoscopic procedures and may expand their application in other areas of neurosurgical management.

Intracranial chondroma in a patient with Ollier's disease

1989 ◽  
Vol 70 (2) ◽  
pp. 274-276 ◽  
Author(s):  
Robert F. Traflet ◽  
Ashok R. Babaria ◽  
Giancarlo Barolat ◽  
H. T. Doan ◽  
Carlos Gonzalez ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Computerized Tomography ◽  
Diagnostic Value ◽  
Resonance Imaging ◽  
Content Type ◽  
Ollier’S Disease ◽  
Intracranial Chondroma ◽  
Ollier's Disease ◽  
Fine Print

✓ A case is presented in which a solitary chondroma arose from the clivus of a patient with Ollier's disease. These tumors are rare. The diagnostic value of computerized tomography and magnetic resonance imaging is discussed.

Sources of error in comparing functional magnetic resonance imaging and invasive electrophysiological recordings

2000 ◽  
Vol 93 (2) ◽  
pp. 214-223 ◽  
Author(s):  
Derek L. G. Hill ◽  
Andrew D. Castellano Smith ◽  
Andrew Simmons ◽  
Calvin R. Maurer ◽  
Timothy C. S. Cox ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Healthy Volunteers ◽  
Hand Movement ◽  
Epileptogenic Zone ◽  
Imaging Data ◽  
Functional Magnetic Resonance ◽  
Reliable Technique ◽  
Content Type ◽  
The Brain ◽  
Fine Print

Object. Several authors have recently reported studies in which they aim to validate functional magnetic resonance (fMR) imaging against the accepted gold standard of invasive electrophysiological monitoring. The authors have conducted a similar study, and in this paper they identify and quantify two characteristics of these data that can make such a comparison problematic.Methods. Eight patients in whom surgery for epilepsy was performed and five healthy volunteers underwent fMR imaging to localize the part of the sensorimotor cortex responsible for hand movement. In the patient group subdural electrode mats were subsequently implanted to identify eloquent regions of the brain and the epileptogenic zone. The fMR imaging data were processed to correct for motion during the study and then registered with a postimplantation computerized tomography (CT) scan on which the electrodes were visible. The motion during imaging in the two groups studied, and the deformation of the brain between the preoperative images and postoperative scans were measured.The patients who underwent epilepsy surgery moved significantly more during fMR imaging experiments than healthy volunteers performing the same motor task. This motion had a particularly increased out-of-plane component and was significantly more correlated with the stimulus than in the volunteers. This motion was especially increased when the patients were performing a task on the side affected by the lesion. The additional motion is hard to correct and substantially degrades the quality of the resulting fMR images, making it a much less reliable technique for use in these patients than in others. Also, the authors found that after electrode implantation, the brain surface can shift more than 10 mm relative to the skull compared with its preoperative location, substantially degrading the accuracy of the comparison of electrophysiological measurements made in the deformed brain and fMR studies obtained preoperatively.Conclusions. These two findings indicate that studies of this sort are currently of limited use for validating fMR imaging and should be interpreted with care. Additional image analysis research is necessary to solve the problems caused by patients' motion and brain deformation.

Cerebellar mutism associated with a midbrain cavernous malformation

2002 ◽  
Vol 96 (3) ◽  
pp. 607-610 ◽  
Author(s):  
Marjorie C. Wang ◽  
Ken R. Winston ◽  
Robert E. Breeze
Keyword(s):  
Magnetic Resonance ◽  
Cavernous Malformation ◽  
Magnetic Resonance Images ◽  
Cerebellar Lesion ◽  
Cerebellar Mutism ◽  
Content Type ◽  
Dysarthric Speech ◽  
Per Se ◽  
Normal Speech ◽  
Fine Print

✓ The authors report a case of cerebellar mutism arising from a hemorrhagic midbrain cavernous malformation in a 14-year-old boy. No cerebellar lesion was identified; however, edema of the dorsal midbrain was noted on postoperative magnetic resonance images. Dysarthric speech spontaneously returned and then completely resolved to normal speech. This case provides further evidence for the theory that involvement of the dentatothalamic tracts, and not a cerebellar lesion per se, is the underlying cause of “cerebellar” mutism.

Obstructive hydrocephalus caused by an abnormal vein in the aqueduct

1991 ◽  
Vol 75 (6) ◽  
pp. 960-962 ◽  
Author(s):  
Akira Watanabe ◽  
Ryoji Ishii ◽  
Masaki Kamada ◽  
Yasuo Suzuki ◽  
Kazuhiro Hirano ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Computerized Tomography ◽  
Ventriculoperitoneal Shunt ◽  
Obstructive Hydrocephalus ◽  
Aqueductal Stenosis ◽  
Resonance Imaging ◽  
Content Type ◽  
Fine Print

✓ A case is reported of aqueductal stenosis caused by an abnormal draining vein and demonstrated by computerized tomography and magnetic resonance imaging. Placement of a ventriculoperitoneal shunt relieved the patient's progressive headaches.

High-field magnetic resonance imaging in patients with moyamoya disease

2001 ◽  
Vol 94 (2) ◽  
pp. 233-237 ◽  
Author(s):  
Atsuko Harada ◽  
Yukihiko Fujii ◽  
Yuichiro Yoneoka ◽  
Shigekazu Takeuchi ◽  
Ryuichi Tanaka ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Healthy Volunteers ◽  
Moyamoya Disease ◽  
Cerebral Circulation ◽  
High Field ◽  
Magnetic Resonance Images ◽  
Cerebral Hypoperfusion ◽  
Content Type ◽  
Fine Print

Object. The purpose of this study was to assess the utility of high-field magnetic resonance (MR) imaging as a quantitative tool for estimating cerebral circulation in patients with moyamoya disease. Methods. Eighteen patients with moyamoya disease who were scheduled to undergo revascularization surgery and 100 healthy volunteers were examined using T2-reversed MR imaging performed using a 3-tesla system. Ten of the 18 patients underwent a second study between 1 year and 3 years after revascularization. Magnetic resonance images obtained in the patients with moyamoya disease were statistically analyzed and compared with those obtained in healthy volunteers. The MR imaging findings were also correlated with results of single-photon emission computerized tomography and conventional cerebral angiography studies. Transverse lines in the white matter (medullary streaks) were observed in almost all persons. In healthy volunteers, the diameter sizes of the medullary streaks increased significantly with age (p < 0.001). Multiple logistic regression analysis revealed that age-adjusted medullary streak diameters were significantly larger in patients with moyamoya disease (p < 0.001). Diameter sizes also increased significantly with the increased severity of cerebral hypoperfusion (p < 0.001) and a higher angiographically determined stage of the disease (p < 0.001). Diameter sizes decreased significantly after surgery (p < 0.001). Conclusions. The increases in medullary streak diameters observed in patients with moyamoya disease appear to represent vessels dilated due to cerebral hypoperfusion. High-field T2-reversed MR imaging is useful in estimating cerebral circulation in patients with moyamoya disease.

Magnetic resonance imaging and computerized tomography scanning of herpes simplex encephalitis

1987 ◽  
Vol 67 (4) ◽  
pp. 592-594 ◽  
Author(s):  
Eric W. Neils ◽  
Robert Lukin ◽  
Thomas A. Tomsick ◽  
John M. Tew
Keyword(s):  
Magnetic Resonance Imaging ◽  
Herpes Simplex ◽  
Magnetic Resonance ◽  
Computerized Tomography ◽  
Herpes Simplex Encephalitis ◽  
Ct Scanning ◽  
Magnetic Resonance Images ◽  
Resonance Imaging ◽  
Content Type ◽  
Magnetic Resonance Imaging Mri

✓ The authors present two cases of herpes simplex encephalitis (HSE) in which computerized tomography (CT) scanning and magnetic resonance imaging (MRI) were performed. They also review the literature on the use of these imaging modalities in cases of HSE. The striking changes noted in these cases on T2-weighted magnetic resonance images in comparison to the CT findings suggest that MRI will help speed recognition of nonhemorrhagic HSE abnormalities.

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