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Biomedical subjects

F Earnest

Publications and source records attributed to F Earnest.

At least 19 recordsLinked to original sources
PubMed1999

Suspected non-small cell lung cancer: incidence of occult brain and skeletal metastases and effectiveness of imaging for detection--pilot study.

PURPOSE: To estimate the incidence of occult metastases to the brain and skeleton in patients suspected of having non-small cell lung cancer (NSCLC) (stage higher than T1Nomo) with surgically resectable disease, to assess the accuracy of screening magnetic resonance (MR) imaging and radionuclide bone scanning for help in identifying occult metastases, and to determine the effectiveness of a high dose of MR contrast material. MATERIALS AND METHODS: Twenty-nine patients suspected of having NSCLC localized to the lung or to the lung and regional nodes underwent preoperative MR imaging with contrast material enhancement and radionuclide bone scanning for detection of brain or skeletal metastases. Patients were followed up for 12 months to determine the incidence of clinical metastatic disease. RESULTS: Eight (28%) patients had occult metastatic disease to the brain or skeleton. Brain metastases were identified on MR images in five of six patients. Bone metastases were identified on MR images in four of five patients and on bone scans in three of five patients. MR imaging was no more accurate than bone scanning for skeletal evaluation. A high dose of MR contrast material allowed detection of more metastases and of small lesions. CONCLUSION: Contrast-enhanced MR imaging of the brain is indicated for the exclusion of brain metastases in patients with clinically operable known or possible NSCLC and a large (> 3-cm) lung mass. Skeletal imaging may be indicated if an isolated brain metastasis is detected.

Aged↗
PubMed1997

Evaluation of irreversible compression of digitized posterior-anterior chest radiographs.

The purpose of this article is to assess lossy image compression of digitized chest radiographs using radiologist assessment of anatomic structures and numerical measurements of image accuracy. Forty posterior-anterior (PA) chest radiographs were digitized and compressed using an irreversible wavelet technique at 10, 20, 40, and 80:1. These were presented in a blinded fashion with an uncompressed image for A-B comparison of 11 anatomic structures as well as overall quality assessments. Mean error, root-mean square (RMS) error, maximum pixel error, and number of pixels within 1% of original value were also computed for compression ratios from ratios from 5:1 to 80:1. We found that at low compression (10:1) there was a slight preference for compressed images. There was no significant difference at 20:1 and 40:1. There was a slight preference on some structures for the original compared with 80:1 compressed images. Numerical measures showed high image faithfulness, both in terms of number of pixels that were within 1% of their original value, and by the average error for all pixels. Our findings suggest that lossy compression at 40:1 or more can be used without perceptible loss in the representation of anatomic structures. On this finding, we will do a receiver-operator characteristic (ROC) analysis of nodule detection in lossy compressed images using 40:1 compression.

Artifacts↗
PubMed1993

Simultanagnosia as the initial sign of degenerative dementia.

In a study of 10 patients with degenerative brain disease that manifested as simultanagnosia, our aims were (1) to elucidate their clinical, neuropsychologic, and radiologic findings to determine whether these patients might represent a group distinguishable from those with typical Alzheimer's disease and (2) to help clinicians recognize this entity. All patients were initially examined by ophthalmologists because of visual difficulties, and the simultanagnosia remained undiagnosed until nonophthalmologic complaints developed. Optic ataxia developed in six patients, and all patients had mildly impaired eye movements. All 10 patients could identify colors appropriately. Nine patients had language deficits (anomia, decreased auditory comprehension, alexia, and agraphia) but were fluent and had relative preservation of sentence repetition, and four performed in the normal range on a test of associative fluency. Two patients scored in the normal range on memory tests, all had preserved insight, and nine had no family history of degenerative dementia. The mean age at onset of the disorder was 60 years (range, 50 to 69). Neuroimaging disclosed prominent bilateral occipitoparietal atrophy in nine patients and generalized atrophy in one. With this unusual but consistent clinical, neuropsychologic, and anatomic profile, these patients are clinically distinguishable from those with typical Alzheimer's disease, but until a specific cause has been found, we cannot be certain that they constitute a specific biologic entity. Clinicians should consider this diagnosis in relatively young patients who have slowly progressive nonocular visual complaints.

Aged↗
PubMed1991

Spontaneous carotid-cavernous fistulae in Ehlers-Danlos syndrome Type IV. Case report.

Spontaneous bilateral carotid-cavernous fistulae and cervical artery dissection is reported in a 20-year-old woman with Ehlers-Danlos syndrome Type IV. The clinical features of 16 previously published cases of spontaneous carotid-cavernous fistulae associated with Ehlers-Danlos syndrome Type IV are reviewed, for a total of 17 cases. The mean age of the 14 women and three men was 31.6 years. Only direct fistulae were encountered. Diagnostic neuroangiography carried morbidity and mortality rates of 36% and 12%, respectively; neuroradiological treatment resulted in death in one of six patients. The possible value of desmopressin in the management of these patients is discussed. In view of the risks of arterial puncture and surgery, the authors emphasize the importance of early recognition of Ehlers-Danlos syndrome.

Adult↗
PubMed1988

Cerebral astrocytomas: histopathologic correlation of MR and CT contrast enhancement with stereotactic biopsy.

Gadolinium-labeled diethylenetriaminepentaacetic acid was used as a contrast agent for stereotactic magnetic resonance (MR) imaging in six selected patients with brain tumors who underwent stereotactic biopsy. Regions of contrast enhancement demonstrated by computed tomography (CT) and MR imaging in four of the six patients correlated with areas of malignant neovascularity and endothelial proliferation within solid tumor. Radiation necrosis produced contrast enhancement indistinguishable from that of recurrent neoplasm. Isolated tumor cells within intact white matter were identified in biopsy specimens obtained outside of regions that were depicted as abnormal by contrast material-enhanced CT, as well as by precontrast and postcontrast T1- and T2-weighted MR images.

Adult↗
PubMed1988

Complications of spinal cord arteriography: prospective assessment of risk for diagnostic procedures.

A prospective study was done of complications associated with 134 consecutive diagnostic spinal cord arteriograms in 96 patients (63 men and 33 women aged 17-78 years). Patients were examined for either arteriovenous malformation (n = 88) or tumor (n = 8), as indicated by myelography. Among the complications, 11 (8.2%) were local, five (3.7%) were systemic nonneurologic, and three (2.2%) were neurologic (two were associated with full recovery in less than 24 hours, and one was associated with full recovery in less than 1 week). No specific clinical or technical factors were significantly associated with the development of neurologic complications. Details of the clinical profile, angiographic technique, and pathologic findings for each patient were recorded and analyzed with respect to the potential risk for arteriographic complications. Diagnostic spinal cord arteriography had an acceptable risk within the range of other neuroangiographic diagnostic procedures.

Adult↗
PubMed1987

Vascular malformations of the posterior fossa. Clinical and radiologic features.

Thirty-one patients with vascular malformations of the posterior fossa were studied to determine their clinical presentation and radiologic diagnosis. The most common clinical presentations were acute hemorrhage (68%, 21/31) and progressive or fluctuating focal neurologic deficits resembling those found in other pathologic processes (19%, 6/31). Trigeminal neuralgia and hemifacial spasm occurred in these patients, but they were rarely initial presenting symptoms. Computed tomography, after infusion of contrast medium, was abnormal in 95% (20/21) of the patients. Angiography established or confirmed the diagnosis in most of the patients; however, a negative angiogram, especially in cases with recent hemorrhage, does not exclude the diagnosis.

Adolescent↗
PubMed1987

Delayed leukoencephalopathy in survivors with small cell lung cancer.

Six patients with small cell lung cancer developed a slowly progressive neurologic syndrome characterized by apathy, abulia, memory loss, gait ataxia, and corticospinal tract signs 26 to 50 months (mean, 35.2 months) after prophylactic cranial irradiation and systemic chemotherapy. In each case this was accompanied by CT and/or MRI evidence of changes in the periventricular white matter. These patients are long-term survivors (41 to 69 months) and do not have CNS metastases.

Adult↗
PubMed1986

Therapeutic embolization angiography for extra-axial lesions in the head.

Percutaneous transcatheter arterial embolization has played an increasingly important role in the management of vascular lesions in the head. Embolization can promote thrombosis within vascular tumors and malformations, reduce bleeding and decrease the need for transfusion intraoperatively, and facilitate surgical approaches to otherwise unresectable lesions. It is important for the clinician to be aware of this interventional technique because many of the patients who are considered for embolization are triaged through several different clinical areas, and much can be gained from the collaboration of the clinician, the surgeon, and the angiographer. We performed 31 therapeutic particulate embolization procedures for extra-axial head lesions in 23 patients by using flow-directed techniques. Of these procedures, 11 resulted in vascular occlusion and 15 resulted in 80 to 95% obstruction, as demonstrated by angiography. In 14 patients, embolization was performed preoperatively both to decrease blood loss and to occlude inaccessible or unresectable portions of a lesion. In nine patients, embolization was the sole means of treatment for occluding an abnormal vascular shunt. Two patients (9%) experienced a minor transient neurologic change after the procedure.

Adolescent↗
PubMed1986

Cryptic structural lesions in refractory partial epilepsy: MR imaging and CT studies.

Results of contrast material-enhanced computed tomography (CT) and T2-weighted spin-echo magnetic resonance (MR) imaging were correlated with pathologic findings in 25 patients treated surgically for refractory partial epilepsy. Of 12 lesions present, ten (83%) were detected by MR imaging and seven (58%) by CT scanning. Of nine low-grade gliomas, eight were detected by MR imaging and four by CT scanning. One posttraumatic scar and one case of temporal lobe atrophy were better demonstrated by MR imaging. A small, thrombosed arteriovenous malformation was the only lesion detected by CT scanning but not by MR imaging. No lesions were detected in 13 patients with mild gliosis and one patient with a 1.2-cm grade 1 astrocytoma. Although more sensitive than CT for detection of structural lesions in patients with refractory partial epilepsy, MR imaging resulted in a 25% false-negative diagnostic rate when a repetition time of 2,000 msec and echo time of 60 msec were used. Multi-echo imaging with at least one long echo time may be needed to increase the sensitivity of MR imaging in these patients.

Adolescent↗
PubMed1986

Computer-assisted stereotaxic laser resection of intra-axial brain neoplasms.

Computer interpolation of stereotaxic computerized tomography (CT) scanning data allows the transposition of a tumor volume in stereotaxic space. A stereotaxically directed and computer-monitored CO2 laser is then utilized to vaporize that volume as the surgeon monitors the position of a cursor representing the laser beam against planar contours of the tumor displayed on an operating room computer monitor. Computer-assisted stereotaxic laser microsurgery provides precise three-dimensional control for aggressive resection of deep-seated tumors from neurologically important areas with acceptable postoperative results. Thus, a significant cytoreduction can be achieved in addition to providing a tissue diagnosis and internal decompression. The authors report 83 computer-assisted stereotaxic laser procedures for tumor excision in 78 patients. The tumors were located in the thalamus/basal ganglia in 15 patients, ventricular system in five, corpus callosum in four, brain stem in three, and deep and centrally in the hemispheres in 51. Histologically, there were 26 glioblastomas, seven grade III astrocytomas, 14 grade II astrocytomas, 14 metastatic tumors, nine vascular lesions, and eight miscellaneous lesions. Resection of these subcortical lesions was confirmed by postoperative contrast-enhanced CT scanning. Neurological examinations performed 1 week after the 83 procedures revealed that 48 patients had improved from their preoperative level and 23 were unchanged (12 were neurologically normal preoperatively). Twelve patients had an increase in a preoperative neurological deficit, three of whom died in the postoperative period: one from infection, one from pulmonary emboli, and one from brain-stem edema. The average survival period (37.6 weeks) of patients having glioblastomas treated by this technique and irradiation was no different from that of patients having glioblastomas in more favorable locations treated by conventional surgery and irradiation. Patients with circumscribed lower-grade astrocytomas did better in terms of morbidity and completeness of resection than those with infiltrative neoplasms. Other circumscribed lesions, such as metastatic tumors, vascular lesions, and intraventricular tumors, were easily resected by the technique described.

Adolescent↗
PubMed1985

Magnetic resonance imaging in a routine clinical setting.

The results of magnetic resonance imaging (MRI) examinations in the first 1,000 consecutive patients who were studied by this technique at our institution were reviewed to determine the disease states encountered, the sensitivity and accuracy of results, and the value of the examination as compared with computed tomography and other imaging procedures. The MRI device was a 0.15-tesla resistive magnet that used a variety of saturation recovery, spin echo, and inversion recovery pulse sequences to produce images. MRI was found equal to or superior to other imaging techniques in most cases. Exceptions included organs or body regions that are prone to excessive respiratory or vascular motion, lesions that necessitate exquisite spatial resolution for diagnosis, and lesions in which angulation of the viewing plane is necessary for optimal depiction. Fresh blood and calcification within a lesion were also difficult to detect with use of MRI.

Adolescent↗