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Biomedical subjects

J I Lane

Publications and source records attributed to J I Lane.

16 recordsLinked to original sources
PubMed2006

Subsequent vertebral fractures after vertebroplasty: association with intraosseous clefts.

BACKGROUND AND PURPOSE: Patients with vertebral fractures containing intraosseous clefts may represent a distinct subgroup of vertebroplasty patients, yet the development of subsequent vertebral fractures in this population has not been explored. We tested the hypothesis that after vertebroplasty for intraosseous clefts, subsequent fractures would occur earlier and more frequently than after treatment of non-cleft-containing fractures. METHODS: We retrospectively reviewed 362 patients treated with vertebroplasty for osteoporotic fractures. The location, frequency, and timing of subsequent fractures were compared between 2 subgroups: group 1, patients treated at fractures containing clefts, and group 2, treated patients without clefts. A vertebra-by-vertebra analysis was used to compare the relative risk and timing of subsequent fractures adjacent to vertebrae with or without clefts. RESULTS: Group 1 included 63 patients treated at 65 vertebrae and group 2 included 250 patients treated at 399 vertebrae. Group 1 demonstrated a nearly twofold increased risk of subsequent fracture (odds ratio [OR], 1.90; 95% confidence interval [CI], 1.04-3.49, P = .037). At the vertebral level, the relative risk of subsequent fracture was 2.02 (95% CI, 1.46-2.58; P = .013) times greater adjacent to a treated cleft. Fractures adjacent to any treated level occurred significantly sooner than nonadjacent fracture (P = .0004). The presence of a cleft was not significantly associated with the timing of subsequent fractures. CONCLUSIONS: Patients with osteoporotic vertebral fractures containing clefts are at increased risk for subsequent fractures and treatment of these clefts is associated with increased rates of adjacent fracture. There is no significant difference in the timing of subsequent fractures based on the presence of a cleft.

Bone Cements↗
PubMed2001

Clinical and radiographic features of dural arteriovenous fistula, a treatable cause of myelopathy.

OBJECTIVE: To assess presentation, imaging, treatment, and outcome of patients with myelopathy due to a dural arteriovenous fistula (DAVF). PATIENTS AND METHODS: This retrospective review identified 94 patients with DAVF surgically treated at our institution between June 1985 and December 1999. The mean ages of the 75 men and 19 women were 62.6 years and 63.0 years, respectively (range, 31-83 years). Magnetic resonance imaging was performed in 87 patients, computed tomography-myelography was performed in 37 patients, and spinal angiography was performed in all patients. Initial examination findings were retrospectively adjusted to a modified Aminoff-Logue myelopathy scale. RESULTS: Of the 94 patients, 47 presented with symptoms that worsened with erect posture or Valsalva maneuver. As myelopathy progressed, patients' symptoms increased, and 6 patients had paraplegia at presentation. The mean time from symptom onset to diagnosis was 23 months (range, 2-120 months). Magnetic resonance imaging confirmed the diagnosis in 86 patients; computed tomography-myelography was needed to confirm the fistula in 1 patient. Spinal angiography detected the fistula in all patients. Surgical obliteration of the DAVF was successful in 93 patients; in 1 patient surgery failed because the DAVF was not localized, but acrylic endovascular embolization was successful. No patient experienced permanent morbidity or mortality. Of the 94 patients, 93 improved postoperatively 1 or 2 levels based on a modified Aminoff-Logue scale. Older patients with severe long-term deficits had poor outcomes. CONCLUSIONS: The diagnosis of a DAVF seems to be delayed considerably because DAVF is not included in the differential diagnosis of myelopathy and because of clinicians' unfamiliarity with suggestive or revealing findings on diagnostic imaging. Neurodiagnostic imaging confirms the diagnosis, and spinal angiography localizes the fistula. Surgical intradural disconnection of the DAVF clinically reverses the pathophysiology. Additionally, surgical treatment is associated with low short-term morbidity, no permanent morbidity, and no mortality. If the diagnosis is made early and treatment initiated in such patients, they generally do well.

Adult↗
PubMed2001

Corpus callosal signal changes in patients with obstructive hydrocephalus after ventriculoperitoneal shunting.

BACKGROUND AND PURPOSE: Few reports have documented signal abnormalities within the corpus callosum on MR studies obtained after ventricular decompression in patients with hydrocephalus. Our purpose was to establish the frequency of this finding in shunted patients and attempt to elucidate its cause and clinical significance. METHODS: All patients with hydrocephalus shunted between 1989 and 1999 with postoperative MR studies available for review were included in the study group. Imaging analysis consisted of documenting hypointense signal on T1-weighted sagittal images and hyperintense signal on double-echo T2-weighted axial images within the corpus callosum. RESULTS: Characteristic signal abnormalities in the corpus callosum were noted in nine of 161 patients with shunted hydrocephalus studied with MR imaging. All nine patients were asymptomatic in regard to these MR findings. Comparison with preoperative scans and surgical records revealed that all patients with signal changes on postshunt scans had chronic obstructive hydrocephalus at presentation. Preshunt MR images were notable for marked elevation of the corpus callosum, which subsequently descended after ventricular decompression, suggesting that the cause of the signal changes was related to compression of the corpus callosum against the rigid falx. CONCLUSION: Signal abnormalities within the corpus callosum after ventricular shunting for obstructive hydrocephalus are not uncommon and are probably produced by compression of the corpus callosum against the falx before ventricular decompression. This distinctive appearance should not be mistaken for significant disease. Recognition of this pattern of signal abnormality will help avoid unnecessary intervention.

Adult↗
PubMed2000

Migration of an intraspinal schwannoma documented by intraoperative ultrasound: case report.

BACKGROUND: Tumors of the cauda equina may shift with positioning on the operating table. Accurate localization at surgery is important to facilitate appropriate laminectomy and durotomy. CASE DESCRIPTION: We report a case of a 28-year-old man with a schwannoma of the cauda equina at L4 on preoperative MRI. Intraoperative ultrasound revealed that the tumor had migrated cephalad, and was now located at L3. CONCLUSION: Intraoperative ultrasound is a valuable technique in localization of tumors of the cauda equina.

Adult↗
PubMed2000

Transcranial-transdural real-time ultrasonography during transsphenoidal resection of a large pituitary tumor. Case report.

Ultrasonography has been used in neurosurgical operative procedures for several decades. The authors report the case of a large pituitary tumor that was subtotally resected using endoscopy via the transnasal-transsphenoidal approach, with the aid of transcranial real-time ultrasound. To our knowledge, this is the first reported case in which intraoperative transcranial-transdural real-time ultrasound was used to facilitate the resection of a skull base tumor.

Adenoma↗
PubMed1996

MR imaging of the lumbar spine: enhancement of the radicular veins.

Enhancement of lumbar nerve roots in the setting of degenerative disk disease has been considered by several authors as evidence of a breakdown in the blood-nerve barrier induced by nerve root compression [1-3]. Unfortunately, correlation between radicular enhancement and the clinically determined level of radiculopathy has not been consistently shown [4, 5]. We recently proposed that this phenomenon represents intravascular enhancement of radicular veins that travel adjacent to or within the endoneurium of one or more nerve roots of the cauda equina [4, 5]. Our purpose in this pictorial essay is to illustrate the appearance of radicular vein enhancement so that this phenomenon will not be misinterpreted as being clinically significant in the setting of degenerative disk disease.

Humans↗
PubMed1995

Contrast-enhanced radicular veins on MR of the lumbar spine in an asymptomatic study group.

PURPOSE: To determine whether radicular enhancement occurs in asymptomatic persons and, if so, to provide insight into the mechanism of such enhancement. METHODS: Thirty asymptomatic volunteers were studied with gadolinium-enhanced MR (0.1 mmol/kg) of the lumbar spine. The precontrast axial T1-weighted sequences were reviewed for the entry section phenomenon of flow-related enhancement. If present, the sequence was repeated in combination with a superior saturation pulse in an attempt to eliminate this phenomenon. All studies were reviewed to document the incidence of radicular enhancement and determine its association with the entry section phenomenon. RESULTS: The entry section phenomenon was observed in 16 of 30 volunteers with successful elimination obtained in all cases. Eighteen of the volunteers demonstrated radicular enhancement; 16 of the 18 enhancing roots were associated with the entry section phenomenon. CONCLUSIONS: Radicular enhancement occurs commonly in asymptomatic volunteers. This phenomenon most likely represents the enhancement of prominent radicular veins. We urge caution in interpreting this finding as abnormal in the symptomatic population with degenerative disk disease.

Adult↗
PubMed1994

Frontal sagittal meningioma: tumor parasitization of cortical vasculature as the etiology of peritumoral edema. Case report.

Peritumoral edema surrounding meningiomas is poorly understood; however, several theories have been proposed in the literature. A case is presented here of a frontal sagittal meningioma symmetrically effacing both frontal lobes that subsequently evokes peritumoral edema on only one side. The tumor is histologically identical on the left and right sides. Angiograms were obtained that support previous work, which suggests that the degree of cortical parasitization of blood supply correlates with peritumoral edema whether or not tumor secretory factors are involved.

Adult↗
PubMed1994

Enhanced lumbar nerve roots in the spine without prior surgery: radiculitis or radicular veins?

PURPOSE: To evaluate the clinical significance of continuous intradural lumbosacral nerve root enhancement in symptomatic patients without prior lumbar surgery. METHODS: Fifty-three patients without prior back surgery, referred to our institution for evaluation of low-back pain and radiculopathy, were studied with gadolinium-enhanced MR (0.1 mmol/kg) of the lumbar spine. Scans were reviewed for the presence of lumbosacral nerve root enhancement and any associated nerve root compression. Results were correlated with clinical history and physical examinations. RESULTS: Seventeen continuously enhancing nerve roots and two enhancing fila terminale were observed in 13 patients. Eight of 17 (47%) had no referable symptoms. Nine of these nerve roots (53%) were not associated with any degree of nerve root compression. Seven cases (41%) were noted to have flow-related enhancement on the entry section of the T1-weighted axial sequence. CONCLUSIONS: Lumbosacral nerve root enhancement correlates poorly with clinical radiculopathy. The use of contrast enhancement to detect lumbosacral nerve root enhancement in cases in which the unenhanced scan is less than diagnostic is not warranted. The high association between lumbosacral nerve root enhancement and entry-section flow-related enhancement suggests that these enhancing structures within the cauda equina are vessels. It is likely that lumbosacral nerve root enhancement represents intravascular enhancement of radicular veins and not a breakdown in the blood-nerve barrier.

Adult↗
PubMed1993

Spontaneous thrombosis of posterior cerebral artery aneurysm with angiographic reappearance. Case report.

The case is presented of a 23-year-old man suffering ischemic brain infarction from spontaneous thrombosis of a left posterior cerebral artery P1-P2 junction aneurysm. Vasospasm and/or partial parent vessel occlusion were documented by magnetic resonance (MR) imaging and angiography. Repeat cerebral angiography and MR imaging 3 months later revealed patency of the posterior cerebral artery and luminal filling of a 1-cm fusiform aneurysm, which was successfully trapped at surgery.

Adult↗
PubMed1993

Magnetic resonance imaging related to neurologic outcome in cervical spinal cord injury.

The purpose of this study was to examine the relationship between the initial intramedullary hemorrhage, as seen by magnetic resonance imaging (MRI), and the neurologic deficit and eventual neurologic outcome of acute cervical spinal cord injured subjects. MRI and motor assessments were performed on 24 subjects with motor complete (Frankel A & B) and incomplete (Frankel C & D) injuries. Recovery was determined by evaluating an initial and a final motor power following spinal cord injury (SCI), as defined by the manual muscle test (grade 1-5) and motor index score (MIS). Results showed that all 15 subjects having hemorrhage had motor complete injuries (Frankel A & B). Sixteen percent of the muscles in the upper extremities and 3% of the muscles in the lower extremities in these 15 subjects improved to a grade of > or = 3/5 at the final evaluation post-SCI. In comparison, of the nine subjects not having hemorrhage, eight had motor incomplete injuries (Frankel C & D) and had 73% and 74% of muscles improving in the upper and lower extremities, respectively. In addition, a change in MIS from initial to final evaluations showed a significant difference between subjects with hemorrhage and subjects without hemorrhage (upper extremities: p = .002 and lower extremities: p = .0001). In conclusion, the initial MR image and neurologic assessment correlated with motor power recovery.

Adolescent↗
PubMed1988

A false-positive hepatobiliary scan in a patient with cystic fibrosis.

A case of nonvisualization of the gallbladder in an adult patient with cystic fibrosis in the absence of acute cholecystitis is reported. Delayed images to 20 hours showed persistent nonvisualization. Review of the literature on cystic fibrosis suggests that nonvisualization of the gallbladder may be secondary to inspissated mucus rather than acute cholecystitis, and therefore a positive hepatobiliary scan in these patients should be interpreted with caution.

Adult↗
PubMedDate not supplied

Imaging of hydrogel episcleral buckle fragmentation as a late complication after retinal reattachment surgery.

Hydrogel encircling bands were introduced in the early 1980s as a product that was superior to bands composed of silicone rubber or silicone sponge for the surgical treatment of retinal detachment. Late complications consisting of orbital swelling and diplopia requiring band removal began to be reported in the early 1990s. Pathologic studies of these expanded fragments of hydrogel material after removal showed in vivo hydrolysis with foreign body reaction and dystrophic calcification. We report the imaging findings in five patients in whom this late complication developed. Hydrogel fragmentation has a characteristic imaging appearance consisting of a circumferential orbital mass associated with rim enhancement. This appearance should prompt inquiries regarding previous scleral buckle procedures with hydrogel bands. Familiarity with this appearance will avoid misinterpretation and unwarranted biopsy before band removal.

Aged↗
PubMedDate not supplied

Assessment of carotid artery patency on routine spin-echo MR imaging of the brain.

We retrospectively reviewed the routine spin-echo MR studies of the brain in 12 patients with 13 angiographically demonstrated occlusions and in 14 patients with 16 high-grade stenoses of the carotid arteries. Intraluminal signal that was isointense with adjacent brain on long TR/short TE and long TR/long TE images was 100% specific for atherosclerotic occlusion. Of the 13 proved occlusions, six (46%) had significant degrees of hyperintense intraluminal signal indistinguishable from that observed consequent to slow flow distal to high-grade stenoses. MR detected only five (31%) of the 16 proved high-grade stenoses. Normal flow void does not exclude significant extracranial carotid stenosis. Occlusion cannot always be distinguished from high-grade stenosis when hyperintense intraluminal signal is encountered. However, a reliable diagnosis of atherosclerotic occlusion can be made when isointense intraluminal signal is observed.

Adult↗