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Biomedical subjects

R E Laster

Publications and source records attributed to R E Laster.

11 recordsLinked to original sources
PubMed2000

Rapid growth of a basilar aneurysm.

We describe a patient who developed, over a 22-month period, a giant aneurysm of his basilar artery. A prior MRI of the brain done for nonspecific symptoms showed a normal brainstem and basilar artery. At presentation, he had a repeat MRI scan for a 4-month history of a partial right oculomotor nerve palsy and left hemiparesis. The MRI revealed a giant aneurysm of the top of the basilar artery. This was treated by angiographic placement of Guglielmi detachable coils (GDC) after surgical intervention was deemed unfeasible. This case illustrates the acquired nature of intracranial aneurysms. All inoperable intracranial aneurysms should be closely monitored and MRI and MR angiography may currently be the best noninvasive methods for this purpose. Intra-arterial GDC embolization of aneurysms is an alternative treatment when surgery is not possible.

Basilar Artery↗
PubMed1996

Repeat CT or MRI in posttraumatic headache.

Repeat CT or MRI of the brain should be considered in posttraumatic headache. We describe two patients with posttraumatic headache who had negative CT scans on initial presentation. One patient later had bilateral subdural hematomas on CT, and the other had temporal lobe hemorrhage on MRI. We recommend considering repeat CT or MRI for persisting posttraumatic headache and mental status change.

Adult↗
PubMed1991

Headaches due to spontaneous internal carotid artery dissection magnetic resonance imaging evaluation and follow up.

Spontaneous internal carotid artery (ICA) dissection is not an infrequent cause of headache and acute neurologic deficits in the younger population. Angiography has been the imaging modality of choice for both diagnosis and follow-up. The use of magnetic resonance imaging, (MRI), in conjunction with angiography, is described in three patients shown to have ICA dissection. Our clinical findings suggest that MRI may provide a less expensive, non-invasive, diagnostic and particularly a follow up modality in patients with headache and signs suggestive of ICA dissection.

Adult↗
PubMed1989

Magnetic resonance imaging of the brain in bacterial endocarditis.

Computed tomographic scanning of the brain is useful but not always conclusive in delineating central nervous system involvement in patients with bacterial endocarditis. Two patients are described in whom computed tomographic findings were normal, but magnetic resonance imaging revealed evidence of multiple brain abnormalities. Magnetic resonance imaging appears to be more sensitive than computed tomography for detecting central nervous system involvement in patients with bacterial endocarditis and should be employed when computed tomographic findings are normal in a patient with endocarditis and neurologic deterioration.

Adult↗
PubMed1984

Evaluation of vascular rings with digital subtraction angiography.

Seven patients with vascular rings were evaluated over a 2-year period with intravenous digital subtraction angiography (DSA), which was compared with screen-film aortography or cineangiography. The seven patients were also evaluated with barium esophagography. Six of the seven DSA images were totally diagnostic and one study was only partly diagnostic. Six of the seven vascular anomalies were confirmed surgically. DSA is suggested as an alternative to arteriography in evaluating patients with suspected vascular rings.

Aorta, Thoracic↗
PubMedDate not supplied

The disposition and cerebrospinal fluid penetration of morphine and its two major glucuronidated metabolites in adults undergoing lumbar myelogram.

STUDY OBJECTIVE: To determine the pharmacokinetic disposition of morphine and its two major glucuronidated metabolites, morphine-6-glucuronide (M6G) and morphine-3-glucuronide (M3G), in serum and their penetration into cerebrospinal fluid (CSF). DESIGN: A single-dose, open-label pharmacokinetic study. SETTING: The Memphis Neurosciences Center at Methodist Hospital. PATIENTS: Twenty patients undergoing a diagnostic lumbar myelogram. INTERVENTIONS: All patients received morphine sulfate 10 mg intramuscularly approximately 1.5 hours before the procedure. MEASUREMENTS AND MAIN RESULTS: Three blood samples were drawn after the dose and a CSF sample was drawn immediately after lumbar puncture. The mean +/- standard deviation for the half-life of morphine was 2.8 +/- 1.4 hours. The apparent half-lives of M6G and M3G were 5.7 +/- 3.1 and 6.3 +/- 2.2 hours, respectively, and were inversely related to the estimated creatinine clearance (r = -0.61, p < 0.007 and r = -0.69, p < 0.002, respectively). The mean concentrations of morphine, M6G, and M3G in the CSF (collection time 1.5 +/- 0.32 hrs, n = 19) were 3.1 +/- 3.7, 12.5 +/- 17.6, and 19.6 +/- 16.1 nmol/L, respectively. CONCLUSIONS: Elderly patients and patients with renal dysfunction receiving morphine may experience prolonged analgesic and adverse effects secondary to a decrease in the clearance of M6G.

Adult↗
PubMedDate not supplied

Assessment of MR angiography versus arteriography for evaluation of cervical carotid bifurcation disease.

PURPOSE: To assess the accuracy of MR angiography alone in screening for vascular stenosis of the common carotid bifurcation. METHODS: Two hundred two common carotid bifurcations in 101 patients were evaluated with MR angiography and selective contrast arteriography. A two-dimensional time-of-flight pulse sequence was used to obtain sequential transverse images through the common carotid bifurcations. These images were reprojected with a maximum intensity pixel ray-tracing algorithm. Both examinations were blindly graded as either normal or mildly stenotic (0%-29%), moderately stenotic (30%-69%), severely stenotic (70%-99%), or occluded. RESULTS: Of the 202 common carotid bifurcations, 119 were classified as normal-mild stenosis by contrast arteriography. In this category, MR angiography correctly identified 114 of these as normal to mild stenosis. Among 21 common carotid bifurcations graded as moderate stenosis by arteriography, 15 were correctly graded as moderate by MR angiography. Among 45 common carotid bifurcations graded as severe stenosis by arteriography, 41 of these were correctly graded as severe by MR angiography. There were 17 complete occlusions which were all correctly graded by MR angiography. CONCLUSION: MR angiography with its high rate of agreement with contrast arteriography can be regarded as an accurate screening method of the common carotid bifurcation.

Adult↗