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Results for “computational morphology”

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At least 703 records · Page 39Linked to original sources

PubMed1997

Malignant gonadal stromal tumor with bulky metastasis at diagnosis.

A 63-year-old man underwent inguinal orchiectomy for painless enlargement of the left testis. The diagnosis of malignant gonadal stromal tumor was made on the basis of morphology and immunohistochemical studies. At computed tomography there was bulky retroperitoneal metastasis. The patient then underwent retroperitoneal lymphadenectomy and received 6 courses of platinum-based chemotherapy at the end of which complete response was documented. However, at 18 months' follow-up, computed tomography revealed recurrent retroperitoneal metastasis. The patient was put on chemotherapy regimen again. But he developed pulmonary metastasis and died 28 months after the initial diagnosis. The clinical course of this patient suggests that malignant gonadal stromal tumor, if metastatic at diagnosis, may have a poor prognosis against most aggressive treatment approaches.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1991

Death and functional outcome after spontaneous intracerebral hemorrhage. A prospective study of 166 cases using multivariate analysis.

Using death and functional status as end points, we prospectively analyzed the outcome 6 months after spontaneous intracerebral hemorrhage in 166 patients admitted to an acute-care stroke unit on the first day of their stroke. Seventy-one patients (43%) died, 69 (42%) had a satisfactory outcome, and 26 (16%) had a poor functional outcome. Early (30-day) survival was correlated with morphologic parameters on the initial computed tomogram (hemorrhage size, midline shift, and intraventricular spread of the hemorrhage), while later (6-month) survival was correlated with age. Using logistic regression, we found five independent predictors of satisfactory outcome at 6 months: age, hemorrhage size, intraventricular spread of the hemorrhage, limb paresis, and communication disorders. Of these, age was the most important predictor by far.

Adult↗

PubMedDate not supplied

Does amateur boxing lead to chronic brain damage? A review of some recent investigations.

Fifty former amateur boxers were examined and compared with two control groups of soccer players and track and field athletes. All subjects were interviewed regarding their sports career, medical history, and social variables. They underwent a physical and a neurologic examination. Personality traits were investigated and related to the platelet monoamine oxidase activity. Cerebral morphologic changes were evaluated using computed tomography and magnetic resonance imaging. Further, clinical neurophysiologic tests were made as well as neuropsychologic tests. No significant differences were found between the groups in any of the physical or neurologic examinations or in platelet monoamine oxidase activity. Socially, the boxers had a lower degree of education and had chosen less intellectual professions, but they were less impulsive and more socialized. The computed tomography images and magnetic resonance imaging studies showed no significant differences between the groups. There was a significantly higher incidence of slight or moderate electroencephalography deviations among the boxers. Neuropsychologically, the boxers had an inferior finger-tapping performance. Thus, no signs of serious chronic brain damage were found among any of the groups studied. However, the electroencephalography and finger-tapping differences between the groups might indicate slight brain dysfunction in some of the amateur boxers.

Adult↗

PubMed2003

Wetting between parallel fibres; column-unduloid and column disintegration transitions.

Wetting phenomena are studied for a fibre bundle consisting of three parallel cylinders of radius b. Two types of long liquid column (a disintegrated and a channel-filling column) and a state akin to the unduloid can form, depending on whether the cylinder-cylinder separation, 2d, is larger or smaller than certain critical values. The dimensionless threshold values d/b have been calculated, when gravity can be neglected and the liquid-fibre contact angle is zero. The threshold value for the morphological transition between disintegrated columns and channel-filling columns occurs for (d/b)tr1 = 0.07869, and the transition between channel-filling column and unduloid sets in when (d/b)tr2 = 2.85337. The existence of the first type of morphological transition is validated by computer simulation based on the Ising model and the Monte Carlo method, as well as by experiments carried out with steel cylinders and epoxy resin.

Absorbent Pads↗

PubMed2005

Metabolic monitoring of chemosensitivity with 18FDG PET.

Accurate and early evaluation of tumor response to chemotherapy is a growing clinical need for optimal management of oncology patients. This is even more warranted by the lack of appropriate response evaluation criteria to new molecularly targeted anticancer therapies. In the two last decades, new developments in the field of nuclear oncology have allowed the introduction of various radiopharmaceuticals to be used on dedicated imaging devices. In the present chapter, we report the added value that positron emission tomography (PET) with 18F-fluorodeoxyglucose (18FDG) may offer to assess tumor response to treatment. PET is a high-end imaging technology using 18FDG as metabolic tracer that mimics the biochemical behavior of the natural glucose molecule. Because most tumor types exhibit increased glucose metabolism, the imaging of 18FDG uptake within cancer tissues prior to any treatment enables the metabolic technique to follow tumor responsiveness sequentially after one or several courses of chemotherapy. Moreover, metabolic tumor response evaluated by 18FDG PET often precedes morphological tumor changes measured by computed tomography or magnetic resonance imaging. So far, the suboptimal proper ties of 18FDG tracer and the lack of standardized methodology in PET imaging remain objective limitations for qualitative and quantitative assessment of chemosensitivity using the metabolic method.

Body Weight↗

PubMed1983

Normal adrenal glands in small cell lung carcinoma: CT-guided biopsy.

Twenty-four small cell lung carcinoma patients with morphologically normal adrenal glands by computed tomographic (CT) criteria underwent percutaneous thin-needle biopsy of their adrenal glands. Of 43 glands biopsied, 29 had adequate cellular material for interpretation. Five (17%) of the 29 glands were positive for metastases; the rest had negative biopsies. This series indicates an approximate 17% false-negative diagnosis rate by CT when staging the adrenal glands in patients with small cell lung carcinoma. It also demonstrates the utility of percutaneous needle biopsy as an investigational tool to further evaluate normal-sized adrenal glands in the oncologic patient.

Adrenal Gland Neoplasms↗

PubMed1988

Effect of pH on the velocity of erythrocyte aggregation.

The effect of pH on the velocity of aggregation of human erythrocytes was quantitatively examined with a rheoscope combined with a video-camera, an image analyzer and a computer, in relation to the morphological changes of erythrocytes and their aggregates. (i) With increasing pH of the medium, the velocity of erythrocyte aggregation increased. (ii) The rouleaux formed at high pH were longer in shape and more stable against the increase of shear rate than those formed at low pH. (iii) With increasing pH, the diameter of erythrocyte increased, the (maximum) thickness decreased, and the cell volume decreased. The pH dependency of erythrocyte aggregation may be mainly due to the morphological change of erythrocytes, and partly due to the changes of erythrocyte deformability and of interaction with macromolecules.

Erythrocyte Aggregation↗

PubMed2001

[CT screening of vertebrarterial circulatory disorder].

The frequency of MR angiography (MRA) used to diagnose vertebrobasilar insufficiency appears high. Findings of abnormality by MRA show cases with maldescription of hemivertebral artery. In such cases, it is unclear whether these are due to anaplasia of the vertebral artery or to the existence of morbid constriction, thus requiring confirmation by a vertebral arteriography (VAG). We observe the vascular morphology of vertebral artery by Computed tomography (CT) scanning for screening circulatory disorders. In photography and CT scan reading, the region was severally photographed between foramen magnum and aortic arch by plain CT and contrast CT at a slice of 5 mm. The constrictive region of the vertebral artery was estimated by comparing plain and contrast CT. Subjects were 34 clinical cases of vascular maldescription in the vertebrobasilar artery, nearly no blood vessel description, or blood vessel winding or inclination. We determined the constrictive morbid state of the vertebral or subclavian artery and cervical vertebra deformity. In findings of maldescription by MRA, it was suggested that discrimination is feasible to a certain degree, whether the vertebral artery has a morbid constrictive region or due to anaplasia. Our results suggest that screening by CT scanning may be more efficient than that by MRA.

Aged↗

PubMed2000

[Mesenteric localization of Castleman's disease].

Castleman's disease (or angiofollicular lymph node hyperplasia) is a rare pathologic process of unknown etiology. Commonly, it is an unique tumor localized in the mediastinum (unicentric disease). Extrathoracic localizations are however reported with an increasing frequency. We describe two cases of mesenteric Castleman's disease. Diagnosis can be suggested by preoperative morphologic explorations (ultrasonography with Doppler, computed tomography scan, magnetic resonance imaging and angiography) and confrontation with clinical and biological data (young age, biological signs of inflammation). In the classical unique tumor of hyalin-vascular type, surgical removal allows definitive cure. Prognosis is poor in the plasma cell type, mostly in multicentric disease due to a high incidence of malignancy.

Adult↗

PubMedDate not supplied

Changes in motion characteristics, plasma membrane integrity, and acrosome morphology during cryopreservation of buffalo spermatozoa.

Motion characteristics, plasma membrane integrity, and acrosome morphology of buffalo spermatozoa after different stages of cryopreservation (ie, dilution, cooling to 4 degrees C, equilibration at 4 degrees C, and freezing and thawing) were examined. Semen ejaculates from 4 buffalo bulls were pooled (n = 5), diluted in tris-citric acid extender, cooled to 4 degrees C over 2 hours, equilibrated at 4 degrees C for 4 hours, dispensed into 0.5-mL straws, and frozen in a programmable cell freezer before plunging into liquid nitrogen. Frozen semen was thawed at 37 degrees C for 15 seconds. After completion of each stage, sperm motion characteristics, plasma membrane integrity, and acrosomal morphology were determined using computer-assisted semen analysis, hypo-osmotic swelling assay, and phase-contrast microscopy, respectively. Data were presented as mean +/- standard error of the mean. Visual and computerized motility did not differ due to dilution, cooling, or equilibration (77.3% +/- 2.3% and 90.5% +/- 1.2%, respectively), but was reduced (P < .05) after freezing and thawing (53.0% +/- 4.6% and 48.6% +/- 6.5%, respectively). Linear motility of spermatozoa was lower (P < .05) after dilution or equilibration (56.2% +/- 2.4%) than after cooling or freezing and thawing (79.6% +/- 1.4%). Sperm curvilinear velocity was reduced (P < .05) from 112.4 +/- 5.3 microm/sec after dilution to 96.0 +/- 5.8 microm/s after cooling, and from 87.6 +/- 4.1 microm/s after equilibration to 69.4 +/- 2.0 microm/s after freezing and thawing. Sperm lateral head displacement differed (P < .05) after each stage (ie, dilution, 3.9 +/- 0.2 microm; cooling, 2.3 +/- 0.2 microm; equilibration, 3.1 +/- 0.3 microm; and freezing and thawing, 1.7 +/- 0.2 microm). Spermatozoa with intact plasma membranes were 80.2% +/- 3.9% after dilution, reduced (P < .05) to 60.4% +/- 5.6% after equilibration, and then to 32.6% +/- 3.8% after freezing and thawing. The percentage of spermatozoa with normal acrosomes remained higher after dilution, cooling, or equilibration (73.2% +/- 2.4%) than after freezing and thawing (61.8% +/- 2.4%; P < .05). In conclusion, the maximal damage to the motility apparatus, plasma membrane, and acrosomal cap of buffalo spermatozoa occurs during freezing and thawing followed by equilibration.

Acrosome↗

PubMed2002

Chest wall lesions.

Chest wall lesions in childhood include a wide range of pathologies. Benign lesions include lipoma, neurofibroma, lymphangioma, haemangioma and mesenchymal hamartoma. Malignant lesions include neuroblastoma, rhabdomyosarcoma, Ewings sarcoma, Askin tumour and primitive neuroectodermal tumours. Manifestations of systemic diseases such as leukaemia, lymphoma, Langerhans cell histocytosis and infections such as tuberculosis and actinomycosis may also cause chest wall lesions. The imaging characteristics of the above are reviewed but only a minority of lesions show diagnostic imaging characteristics. Most lesions require biopsy and histopathological examination for definitive diagnosis. The role of different imaging modalities is discussed, with an emphasis on magnetic resonance imaging for demonstrating lesion morphology and local spread, with computed tomography and nuclear medicine being used mainly to assess remote disease.

Age Factors↗

PubMed2004

Semiautomated image segmentation of bone marrow biopsies by texture features and mathematical morphology.

OBJECTIVE: To present the preliminary results of a method for semiautomated detection of fat and hematopoietic cells as well as trabecular surfaces in bone marrow biopsies in order to calculate the percentage of each type of tissue or cell area in relation to the whole area. STUDY DESIGN: The results were derived from selected clinical cases. Twenty-six biopsies were used, presenting varied distributions of cellularity and trabecular topography. The approach is based on digital image processing techniques and pattern recognition methods using textural features obtained from biopsy images. The results were improved with mathematical morphology filters. RESULTS: A low computational cost algorithm is obtained that produces highly satisfactory results. The method is faster and more reproducible than conventional ones, such as region growing, edge detection, splitting and merging. CONCLUSION: The results with this computer-assisted technique were compared to those obtained by visual inspection by 2 expert pathologists, and differences of < 9% were observed.

Adipocytes↗

PubMed1989

Morphometric analysis of the corneal endothelium. Specular microscopy vs. alizarin red staining.

Computer-assisted analysis of endothelial morphology provides useful indices of cell shape and size which appear to correlate to the monolayer's functional status. In this study morphometric data obtained by wide-field specular microscopy of in situ corneal endothelia are compared to data obtained by alizarin red S staining of excised corneas. Both human donor corneas and rabbit corneas were studied. The results of the study indicate that considerable (14%) cell shrinkage occurs in rabbit endothelia following staining. Associated with this cell shrinkage is a normalization of cell area which is manifest as a significant (P less than 0.001) decrease in the coefficient of variation of cell area. The percentage of hexagonal cells, however, remains unchanged. These changes were not mitigated by lowering the osmolality of the saline rinse following staining or by minimizing evaporation by placing a drop of silicone oil on the stained button. In human tissue no significant differences in cell area or cell shape were noted in comparing morphometric data obtained by staining to that obtained from specular microscopy. Useful morphometric data can be obtained by alizarin staining. This technique combined with cell morphometric analysis could provide valuable data in corneas whose lack of clarity limits or precludes specular microscopy. Caution, however, must be exercised in comparing morphometric data by this method to those obtained in situ for rabbit tissue.

Animals↗

PubMedDate not supplied

[Nuclear medicine diagnosis and treatment in pheochromocytoma and neuroblastoma].

Localization procedures are required in catecholamine producing tumors following clinical and biochemical confirmation of phaeochromocytoma or neuroblastoma. Whereas computed tomography and ultrasound reflect morphological abnormalities, adrenomedullary scintigraphy with radiolabeled meta-iodobenzylguanidine depends on function. MIBG scintigraphy has the advantage of being able to detect intra- and extra-adrenal, uni- and bilateral or multilocular, benign and malignant phaeochromocytomas and neuroblastomas. Especially small lesions and tumor tissue in bone marrow in children with neuroblastoma can be visualized more easily. The same radiopharmaceutical agent radiolabeled with high doses of 131I may be used for treatment of phaeochromocytomas and neuroblastomas stage III and IV. In patients with malignant phaeochromocytomas this therapy may improve clinical symptoms and reduce tumor volume for months or even years, but probably this therapy is not curative. In children with neuroblastoma complete remission may be achieved by combining surgery, chemotherapy, and 131I-MIBG treatment. Therefore, this therapeutic modality should be included in the therapeutic strategy of stage III and IV neuroblastoma.

3-Iodobenzylguanidine↗

PubMedDate not supplied

Cerebellar hemangioblastoma with prominent stromal astrocytosis: diagnostic and histogenetic considerations.

A cerebellar hemangioblastoma with atypical radiologic and morphologic features is reported. On computed tomography this tumor presented as a single ring-enhancing mass in the right cerebellar hemisphere without adjacent cyst formation. It was radiologically indistinguishable from an abscess or malignant neoplasm. Postmortem examination demonstrated a circumscribed, cystic neoplasm arising in the pia at the base of a sulcus. Microscopically, the tumor contained a prominent astrocytic component that mimicked the appearance of a highly vascular astrocytoma. Hemangioblastomas with this degree of astrocytosis are unusual. They must be distinguished pathologically from both cystic astrocytoma and mixed hemangioblastoma-glioma (angioglioma).

Aged↗

PubMed1983

[Functional heterogeneity of the electroexcitable membrane of nerve cells].

The own and literary data connected with a problem of functional heterogeneity of the electroexcitable membrane of the nerve cells is presented. The results which testify the peculiarities of spreading of excitability on somatic membrane of isolated neuronal somata and the form of somatic action potentials studied by using the micro-computer have been analysed. The morphological heterogeneity of the electroexcitable membrane is suggested to be the basis of the electrogenesis action potentials.

Action Potentials↗

PubMed1995

Imaging methods as a diagnostic tool in neuro-AIDS. A review.

Since 1983, central nervous system (CNS) involvement in acquired immune deficiency syndrome (AIDS) is well recognized. Imaging methods are important in diagnosing AIDS-related primary and secondary CNS processes as HIV-1-associated encephalopathy, cerebral toxoplasmosis, primary CNS lymphoma, cytomegalovirus (CMV) encephalitis, progressive multifocal leukoencephalopathy (PML), and infectious spinal cord granulomas. This paper presents a review of typical AIDS-related CNS findings as seen in morphological radiologic techniques, i.e. cranial computed tomography (CCT) or magnetic resonance imaging (MRI). Furthermore, the paper discusses the value of CCT, MRI and functional (positron emission computed tomography = PET, single-photon emission computed tomography = SPECT, and magnetic resonance spectroscopy) as well as morphometric imaging methods in evaluating subclinical HIV-1-related cerebral deficits and predicting their clinical course.

AIDS Dementia Complex↗

PubMed1996

Parathyroid and thyroid imaging.

Whether to perform preoperative imaging for parathyroid adenomas is controversial in the "virgin neck" because surgery without imaging is successful in more than 90% of cases. To detect ectopic adenomas or unresected adenomas after failure of initial surgery often requires both a functional study, such as technetium-99m sestamibi nuclear scintigram, and a morphologic study, such as ultrasonography, computed tomography, or magnetic resonance imaging for anatomic landmarks. Most dominant thyroid masses require fine-needle aspiration for diagnosis. Nuclear scintigraphy is useful when the lesion is warm or hot, making a malignancy less likely, but cold lesions are nonspecific. Unless a mass is shown to infiltrate the surrounding soft tissue or spread to lymph nodes, the findings on most cross-sectional imaging studies are also nonspecific.

Humans↗