PubMed Health⌕ Search

Biomedical subjects

J Bentson

Publications and source records attributed to J Bentson.

At least 19 recordsLinked to original sources
PubMed2000

Volume-rendered helical computerized tomography angiography in the detection and characterization of intracranial aneurysms.

OBJECT: The goal of this study was to evaluate the utility of volume-rendered helical computerized tomography (CT) angiography in patients with intracranial aneurysms. The authors compared the abilities of CT angiography, digital subtraction (DS) angiography, and three-dimensional time-of-flight magnetic resonance (MR) angiography to characterize aneurysms. METHODS: Helical CT angiography was performed in 45 patients with suspected intracranial aneurysms by using volume-rendered multiplanar reformatted (MPR) images. Digital subtraction angiography was performed using biplane angiography. These studies and those performed using MR angiography were interpreted in a blinded manner. Two neurosurgeons and two interventional neuroradiologists independently graded the utility of CT angiography with respect to aneurysm characterization. Fifty-five aneurysms were detected. Of these, 48 were evaluated for treatment. Computerized tomography angiography was judged to be superior to both DS and MR angiography in the evaluation of the arterial branching pattern at the aneurysm neck (compared with DS angiography, p = 0.001, and with MR angiography, p = 0.007), aneurysm neck geometry (compared with DS angiography, p = 0.001, and with MR angiography, p = 0.001), arterial branch incorporation (compared with DS angiography, p = 0.021, and with MR angiography, p = 0.001), mural thrombus (compared with DS angiography, p < 0.001), and mural calcification (compared with DS angiography, p < 0.001, and with MR angiography, p < 0.001). For surgical cases, CT angiography had a significant impact on treatment path (p = 0.001), operative approach (p = 0.001), and preoperative clip selection (p < 0.001). For endovascular cases, CT angiography had an impact on treatment path (p < 0.02), DS angiography study time (p = 0.01), contrast agent usage (p = 0.01), and coil selection (p = 0.02). Computerized tomography angiography provided unique information about 39 (81%) of 48 aneurysms, especially when compared with DS angiography (p = 0.003). The sensitivity and specificity of CT angiography compared with DS angiography was 1. The sensitivity and specificity of CT and DS angiography studies compared with operative findings were 0.98 and 1, respectively. CONCLUSIONS: Computerized tomography angiography is equal to DS angiography in the detection and superior to DS angiography and MR angiography in the characterization of brain aneurysms. Information contained in volume-rendered CT angiography images had a significant impact on case management.

Adolescent↗
PubMed2000

Therapeutic embolization of arteriovenous malformations: the case for and against.

The field of endovascular therapy has demonstrated stunning technical achievements in AVM embolization. Embolization has the potential to enhance the safety and efficacy of AVM treatment when applied in carefully considered cases. The utility of embolization, at the present time, is limited by the fact that the procedure may be associated with disabling or fatal complications, and because complete or near-complete AVM nidus occlusion can be achieved only in a minority of cases. Because of these factors, embolization should not be considered a "standard-of-care" for the management of all cerebral AVMs, and careful case selection for embolization, with well-defined treatment goals in mind, is essential. Finally, not all AVMs that can be embolized should be embolized.

Cerebral Hemorrhage↗
PubMed1999

Diffusion MRI in patients with transient ischemic attacks.

BACKGROUND AND PURPOSE: Diffusion MRI has established value in patients with ischemic stroke but has not been systematically investigated in patients with transient ischemic attack (TIA). METHODS: Clinical, conventional MRI, and diffusion MRI data were collected on 42 consecutive patients with symptoms of cerebral TIA. TIA imaging data were compared with those from a contemporaneous group of 23 completed stroke patients. RESULTS: Twenty of the 42 TIA patients (48%) demonstrated neuroanatomically relevant focal abnormalities on diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) imaging. When present, DWI/ADC signal changes in TIA patients were less pronounced and smaller in volume than those in completed stroke patients. TIA symptom duration was significantly longer for DWI-positive than for DWI-negative patients, 7.3 versus 3.2 hours. Diffusion MRI information changed the suspected anatomic and vascular TIA localization and the suspected etiologic mechanism in over one third of patients with diffusion MRI abnormalities. Of the 20 TIA patients with identifiable lesions on diffusion MRI, 9 had follow-up imaging studies; of these, 4 did not show a relevant infarct on follow-up imaging. CONCLUSIONS: Diffusion MRI demonstrates ischemic abnormalities in nearly half of clinically defined TIA patients. The percentage of patients with a DWI lesion increases with increasing total symptom duration. In nearly half, the diffusion MRI changes may be fully reversible, while in the remainder the diffusion MRI findings herald the development of a parenchymal infarct despite transient clinical symptoms. Finally, diffusion imaging results have significant clinical utility, frequently changing the presumed localization and etiologic mechanism.

Adult↗
PubMed1990

Pre-operative micro-angioplasty of refractory vasospasm secondary to subarachnoid hemorrhage.

A patient with subarachnoid hemorrhage secondary to a basilar artery aneurysm developed severe bilateral middle and anterior cerebral artery vasospasm with extensive neurologic deficits. Microangioplasty of the middle cerebral artery segments bilaterally led to reversal of the neurologic deficits, allowing early operative treatment of the aneurysm in a previously inoperable patient.

Aged↗
PubMed1990

Use of a new mixture for embolization of intracranial vascular malformations. Preliminary experimental experience.

The internal carotid artery system in swine has a special anatomic configuration similar to a brain "arterial-arterial malformation." The internal carotid artery breaks up into a multitude of fine channels (rete mirabile) situated at the base of the skull on the side of the hypophysis. This anatomic arterial model was used to analyze acute and chronic angiographic and histological changes after occlusion of the rete mirabile with I) avitene, II) avitene, and 50% ethanol, III) avitene, 30% ethanol and Polyvinyl alcohol, IV) avitene 50% ethanol and Polyvinyl alcohol, V) IBCA and VI) silk. Histopathological changes observed in the rete mirabile six weeks following occlusion demonstrated that a mixture of avitene, 30% ethanol and Polyvinyl alcohol and IBCA produced the best anatomic results. Embolization with avitene, PVA and ethanol induced a more bland histological reaction than the one observed with IBCA. Preliminary clinical experience with this mixture is reassuring in those cases in which the AVM was surgically resected. The partially thrombosed AVM was easily depressed and compressed by the neurosurgeon allowing for satisfactory hemostasis in and around the nidus of the AVM.

Animals↗
PubMed1990

Intraoperative digital subtraction angiography and the surgical treatment of intracranial aneurysms and vascular malformations.

Intraoperative digital subtraction angiography using commercially available equipment was employed to confirm the precision of the surgical result in 105 procedures for intracranial aneurysms or arteriovenous malformations (AVM's). Transfemoral selective arterial catheterization was performed in most of these cases. A radiolucent operating table was used in all cases, and a radiolucent head-holder in most. In five of the 57 aneurysm procedures, clip repositioning was required after intraoperative angiography demonstrated an inadequate result. In five of the 48 AVM procedures, intraoperative angiography demonstrated residual AVM nidus which was then located and resected. In two cases intraoperative angiography failed to identify residual filling of an aneurysm which was seen later on postoperative angiography, and in one case the intraoperative study failed to demonstrate a tiny residual fragment of AVM which was seen on conventional postoperative angiography. Two complications resulted from intraoperative angiography: one patient developed aphasia from cerebral embolization and one patient developed leg ischemia from femoral artery thrombosis. This technique appears to be of particular value in the treatment of complex intracranial aneurysms and vascular malformations.

Angiography, Digital Subtraction↗
PubMed1989

Neurovascular lesions and endovascular therapy: the role of MR.

Magnetic resonance imaging (MRI) studies were performed on 27 patients with vascular lesions of the central nervous system before and after embolization with either IBCA, polyvinyl alcohol foam particles, Avitene (microfibrillar collagen) or balloons. Thirteen pial brain arteriovenous malformations (AVMs), 3 brain AV fistulas, 2 giant aneurysms, 5 dural AVMs, 1 vertebro-vertebral fistula and 3 meningiomas were studied. The pre-embolization MR demonstrated the nidus and venous drainage of all pial AVMs. MR failed to detect 3 out of 5 dural AVMs using only spin echo sequences. A draining vein alone was seen in the remaining two cases. MR was superior to CT in detecting contiguous parenchymal changes such as atrophy, reversible ischemia, and mass effect in the pre-embolization studies. Following embolization, MR demonstrated partial or complete obliteration of the vascular nidus in all 13 pial AVMs. The embolized area was seen as an area of increased signal consistent with thrombus where previously there had been signal void. Ischemic or edematous changes in the brain parenchyma following embolization were seen on MR more easily than on CT scans. MR was accurate in the assessment of aneurysm patency, degree of thrombosis and balloon position in both giant aneurysms, and AV fistulae. These MR findings had an impact on patient management. MR will be an increasingly useful tool in the diagnosis and management of a number of neurovascular diseases requiring endovascular intervention.

Arteriovenous Malformations↗
PubMed1989

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. The standard stainless steel needles used for CT-guided biopsy are unsuitable for MR-guided biopsy because significant ferromagnetic artifacts obscure the underlying anatomy. A new needle has recently been designed specifically for use with MR imaging. This needle has far less magnetic susceptibility and therefore does not cause significant image distortion. The authors describe the use of this needle in MR-guided aspiration biopsy of a variety of lesions in the head and neck.

Adult↗
PubMed1987

MR imaging of the intratemporal facial nerve by using surface coils.

MR images of the intratemporal portion of the facial nerve were obtained with surface coils using a 0.3-T permanent magnet whole-body imaging system. Various 2DFT spin-echo pulse sequences were used to produce 5-mm thick sections with 0.5-mm pixels on a 512 X 512 acquisition matrix. The MR images from normal volunteers were correlated with cryosection specimens of three fresh human cadavers. The seventh nerve was followed in the internal auditory and fallopian canal and through temporal bone to the stylomastoid foramen. The entire labyrinthine, tympanic, and mastoid portions, as well as the geniculate ganglion, could be shown with appropriate scan planes. MR produces excellent images of the facial nerve with high-contrast resolution. Unlike CT, no beam-hardening artifact from the temporal bone is apparent. MR should be a sensitive study for the evaluation of intratemporal facial nerve disease.

Facial Nerve↗
PubMed1986

Magnetic resonance imaging of the facial nerve. Normal anatomy and pathology.

Magnetic resonance imaging with surface coils permits visualization of the facial nerve from within the brainstem and continuing through a major portion of the parotid gland. Diagnostic capabilities have been expanded to include white matter disease that affects the tracts of the facial nerve within the brainstem and tumors of the parotid gland that involve the facial nerve trunks after the nerve exists from the stylomastoid foramen.

Facial Nerve↗
PubMed1978

The accuracy of predicting histologic grades of supratentorial astrocytomas on the basis of computerized tomography and cerebral angiography.

This report concerns a group of 49 patients who had been diagnosed as having gliomas on the basis of CT scans plus angiograms and for whom histologic proof was available. Ninety percent were found to be gliomas, 4% were metastases, and histology was unclear in the rest. Combining the CT criteria of inhomogeneous enhancement and surrounding edema with one or more of three angiographic signs (early venous drainage, stain, abnormal vessels) allowed a more confident diagnosis of glioblastoma.

Astrocytoma↗
PubMed1978

Unexpected complications following therapeutic embolization.

Unexpected complications may follow therapeutic embolization, even though no apparent technical errors have occurred. This report includes four cases of facial palsy following middle meningeal artery embolization, one case of aspiration pneumonia following glomus tumor embolization, and a case of pulmonary embolization following embolization of a spinal arteriovenous malformation.

Aged↗
PubMed1978

Steroids and apparent cerebral atrophy on computed tomography scans.

Computed tomography scans of 15 long-term steroid users showed varying degrees of apparent cerebral atrophy, not expected at their ages (8 to 40 years). Most were suffering from autoimmune diseases. There appeared to be some correlation between dosage and degree of apparent atrophy. There was surprisingly little clinical evidence of cerebral dysfunction associated with this apparent atrophy. In two of the cases, the appearance of the brain improved following decrease or cessation of steroid use. Speculations are made on possible causes.

Adolescent↗
PubMed1976

Preoperative vascular embolization as an adjunct to successful resection of large retroperitoneal hemangiopericytoma.

A large retroperitoneal hemangiopericytoma was resected successfully with the aid of preoperative control of the blood supply of the lesion with percutaneous intra-arterial gelfoam and ferromagnetic silicone embolization. We believe that this resection would not have been possible without this adjuvant technique. Future application of this combined technique will enable more aggressive surgical intervention in unresectable vascular tumors and arteriovenous malformations.

Adult↗
PubMedDate not supplied

Comparison of T1 and T2 weighted images of the lumbar spine.

In order to develop an optimal routine magnetic resonance (MR) spine scanning protocol, we have compared the relative efficacy of performing T1- and T2-weighted images in patients with various disorders of the lumbar region. Forty cases were randomly selected from studies performed from 1984 to 1987 and the T1- and T2-weighted images of each case were separated and interpreted blindly and independently by two neuroradiologists. Our results indicate no significant difference between T1- and T2-weighted images in the depiction of disc protrusion. The T2-weighted images were superior in depicting disc dessication, but the clinical significance of identifying a dessication disc remains uncertain. No significant difference in the depiction of osteophytes was seen between T1- and T2-weighted images. Cases of tethered cord, metastatic disease, and arachnoiditis were better delineated with T1-weighted images. The increase in signal of cerebrospinal fluid (CSF) with T2-weighting often obscured lesions within the spinal canal. In a signal case of postoperative discitis, the T2-weighted images disclosed disc space abnormalities and epidural fluid collections not appreciated on T1-weighted images. The T1-weighted images, however, did show thecal sac and adjacent epidural extension more clearly. In cases of metastatic disease, increase in the signal of metastases with T2 weighting often rendered them isointense to surrounding medullary bone. Given the lack of superiority of T2-weighted images over T1-weighted images in evaluating intervertebral disc protrusions and the superiority of T1-weighted images in depicting nearly all other abnormalities observed in this series, we no longer acquire T2-weighted images of the lumbar spine on a routine basis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗