SEARCH · PubMed Health

Results for “computational morphology”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

PubMed1992

Short fixation-shock freezing and freeze-drying versus chemical fixation and dehydration: computer assisted image analysis of morphological variables and immunogold labeling density on pituitary secretory granules.

We have performed a computer assisted image analysis evaluation of the effects of two preparation protocols on morphological variables and immunolabeling density of secretory granules using rat adenohypophysis as a model. Glutaraldehyde (GA) fixation for 2 hr and chemical dehydration was compared with short GA fixation (15 min) followed by cryofixation and freeze-drying (CF-FD). The 2 hr GA fixed specimens showed spherical nuclei and secretory granules regardless of their size, contrasting with the more irregularly shaped nuclei and secretory granules after short GA-CF-FD. In the latter group of specimens a correlation could be found between smaller nuclear areas and more irregular shapes. The differences in morphological variables between the two preparation protocols might be due to a better protein stabilization and a reduced collapse of macromolecules after the 2 hr GA fixation, strengthened by the chemical dehydration. The specific immunolabeling with antiserum to growth hormone was much greater but more varied after short time GA-CF-FD than after long GA fixation. Epon surface topography over the granule area also differed: smooth after short time GA-CF-FD and furrowed after long GA fixation. Our results, demonstrating important differences in morphological parameters and immunolabeling density between two common preparation protocols, seem critical for more reliable interpretation in quantitative immunoelectron microscopy. We also emphasize the need for computer assisted image analysis and measurements in immunoelectron microscopy to ensure objective evaluations.

Animals↗

PubMed1999

Computer-generated surgical simulation of morphological changes in microstructures: concepts of "virtual retractor." Technical note.

The authors' goal was to develop a computer graphics model to simulate the displacement and morphological changes that are caused by the retraction of fine intracranial structures. The authors developed an application program to interpolate the contour of models of an artery and a retractor. The center of the displacement was determined by spatial coordinates, and the shape of the displacement of the arterial model was calculated using a cosine-based formula with representation of a brain retractor. This computer graphics model was applied to the simulation of the displacement and morphological changes that occur when retraction is performed in the optic nerve. An illustrative case is presented, in which the optic nerve was displaced by a retractor to simulate the surgery performed in a carotid cave aneurysm of the internal carotid artery. The authors have named this methodological tool a "virtual retractor." This new navigational system for open microneurosurgery would be useful in teaching surgical microanatomy and in presurgical operative planning.

Algorithms↗

PubMed1991

Computer-assisted assessment of human sperm morphology: usefulness in predicting fertilizing capacity of human spermatozoa.

OBJECTIVE: The usefulness of sperm morphology to predict the outcome of human sperm fertilizing capacity was examined. DESIGN, SETTING, PATIENTS: Semen samples from 50 male patients attending the infertility clinic of a tertiary referral institution were studied. MAIN OUTCOME MEASURES: Sperm morphology was classified both by visual assessment and computer-assisted image analysis. In addition, morphometric analysis of the spermatozoa was measured by the morphologizer. Multivariate discriminant analysis was used to evaluate the usefulness of these morphology parameters for predicting the outcome of the zona-free hamster oocyte sperm penetration assay. RESULTS: The manually derived percent of spermatozoa with normal and small head were selected to be of discriminating value in predicting the outcome of the zona-free hamster oocyte penetration test. The accuracy of correctly classifying the outcome of zona-free hamster oocyte penetration test by these two parameters in combination was 84%, whereas assessment of sperm morphology with morphometric analysis by the morphologizer selected a total of eight variables, which together predicted sperm fertilizing capacity with 74% accuracy. Addition of the morphologizer-derived parameters to those derived manually did not significantly improve the predictive value. CONCLUSION: We conclude that the results of the zona-free hamster egg penetration test could be predicted using manual assessment of sperm morphology and computer-assisted morphometric analysis did not add further information.

Animals↗

PubMed1998

[Computer-assisted evaluation of aortic aneurysm morphology for choosing the method of therapy].

Computer aided surgery planning software for AAA is a industry-standard software development for viewing patient-specific data on a personal computer through a unique approach, which improve visualization, navigation, and decision support capabilities for both open and endovascular surgery. Raw scan data is extracted from CT scans, and rendered into a three-dimensional format. This 3D modeling technology and user interface provides a patient-specific model with a rapid visual access to the full range of information, including accurate 3D assessment of AAA morphology and pathology, interactive multiplanar reconstructions, measurements, and views to assist the surgeon in understanding of complex 3D relationships. It provides an optimal system for patient evaluation and selection for endovascular repair of AAA and in the post-operative evaluation of stent deployment and/or complications, such as endoleaks.

Aortic Aneurysm↗

PubMed1997

Coronary calcification and coronary atherosclerosis: site by site comparative morphologic study of electron beam computed tomography and coronary angiography.

OBJECTIVES: We compared, on a site by site basis, the morphologic features of coronary calcifications determined by electron beam computed tomography (EBCT) and angiographically defined coronary atherosclerosis. BACKGROUND: Quantification of coronary calcification using EBCT is clinically useful for the prediction of coronary stenosis. However, the relation between calcification and angiographic findings has not been evaluated by site. METHODS: We studied 251 consecutive patients who underwent elective coronary angiography for suspected coronary artery disease by EBCT and analyzed findings by site. Coronary calcifications were classified according to their length and width versus the diameter of the coronary artery in which the calcification was observed as: none, spotty, long, wide and diffuse. RESULTS: Coronary calcifications were found in 666 (27%) of 2,470 segments. The positive predictive value (PPV) of coronary calcification for significant stenosis (> or = 75% densitometric narrowing) and for all angiographically detectable atherosclerotic lesions in a segment was 0.36 and 0.80, respectively. The PPV for significant stenosis and all atherosclerotic lesions was 0.04 and 0.17 in none, 0.18 and 0.59 in spotty, 0.32 and 0.87 in long, 0.40 and 0.84 in wide and 0.56 and 0.96 in diffuse calcifications, respectively. The PPV for both significant stenosis and all lesions differed significantly (p = 0.001) among the morphologic groups. Of the 105 eccentric significant stenoses, 54 (53%) were classified as long or diffuse calcifications. Of the 95 significant stenoses with multiple irregularities, 61 (64%) showed diffuse calcification. CONCLUSIONS: Morphologic evaluation of coronary calcifications using EBCT improved the prediction of coronary stenosis on a site by site basis and provided information related to angiographic morphology.

Adolescent↗

PubMed1983

[EDP-adapted grid model of the brain for topographic analysis of lesions on the cranial computer tomogram].

A method for the recording and statistical evaluation of computer tomographic morphological data is described. The lesions demonstrated by computer tomography are transferred to a sectional model of the brain on which a grid is superimposed. The sections and grid are then transferred to the Evaluscope (Siemens) and the original CT lesion is recorded with a light-pen and then stored. Statistical evaluation of the data can be carried out centrally and can be combined with the results of other clinical studies.

Aphasia, Broca↗

PubMed1986

[The coding of roentgen diagnostic findings of studies based on morphologic structural changes. A computer assisted archive system for scientific purposes].

For the last three years our Institute has been using a system based on a microcomputer for archiving scientifically interesting findings. This computer processes data obtained via computed tomography, sonography and angiography. Besides the coding of examination findings the system also enables compilation of efficiency statistics data. The system can be extended with comparatively little effort for processing MR data as well. Coding is not effected, as in most of the generally used systems, according to diagnosis, but according to the pathological change that can be detected via x-ray film. This prevents erroneous coding due to erroneous evaluation of the finding in question. The examinations can be stored immediately without waiting for verification. Search for defined findings is effected via screen where a search profile is set up interactively. Due to the hierarchic structure of code allocation it is possible to call for more or less detailed findings from the stored data.

Angiography↗

PubMed1998

Identification of clustered microcalcifications on digitized mammograms using morphology and topography-based computer-aided detection schemes. A preliminary experiment.

RATIONALE AND OBJECTIVES: A mathematical morphology-based computer-aided detection (CAD) scheme for the identification of clustered microcalcifications was developed and tested. The potential for improving either sensitivity or specificity by combining the results with those previously reported was investigated. METHODS: The CAD scheme presented here is based on mathematical morphology and a series of simple rule-based criteria for the identification of clustered microcalcifications. A database of 105 digitized mammograms was used for training and rule setting of the scheme. A test set of 191 digitized mammograms was used to evaluate its performance. The same test set had been used to evaluate a multilayer, topography-based scheme. The results obtained by the two schemes were then combined using logical OR and AND operations. RESULTS: The morphology-based and topography-based CAD schemes performed at sensitivities of 82.9% and 89.5%, with false-positive detection rates of 1.3 and 0.4 per image, respectively. A logical OR operation resulted in 95.4% sensitivity. An AND operation achieved 76.2% sensitivity, with no false identifications on 93% of images. CONCLUSIONS: By combining the results of the morphology-based and the topography-based schemes, either sensitivity or specificity can be improved.

Algorithms↗

PubMed1999

[Computer-based image analysis for experimental and clinical morphology--principles, utilization and marginal limits].

The new computer based image analysis techniques are powerful tools for mophometrical and quantitative image analysis in case of clinical and experimental morphology. Digital image analysis requires a distinction between two phases 1. generation of fundamental data (x,y coordinates and grey values of the pixel) and 2. calculation of parameters from these data. Stereological procedures are very powerful in quantifying morphological phenomenons, but computer based image analysing techniques allow multiple analysis of morphological objects and analysis of statistical distributions. There is great scientific benefit using modern computer based image analysing techniques.

Animals↗

PubMed2000

Computer-generated three-dimensional morphology of the hepatic hilar bile ducts in biliary atresia.

BACKGROUND/PURPOSE: In biliary atresia (BA), although the intrahepatic bile ducts are reported to appear in the fetal configuration in about 20% to 60% of cases, information about the 3-dimensional (3-D) morphology of the hilar biliary structures is limited. The authors, therefore, have applied the technique of computer-generated 3-D reconstruction, to study the morphology of the hilar biliary structures in patients who have undergone biliary decompression. METHODS: Computer-generated 3-D reconstructions were performed from serial sections of the hepatic hilum of 4 BA patients and compared with those obtained from a 3-day old infant who had no apparent biliary disease but died of congenital diaphragmatic hernia (CDH) and with normal human fetal ductal plate at 11 weeks of gestation. RESULTS: In all 4 BA patients, the hilar bile ducts strongly resembled the ductal plate structures of the fetus rather than the bile ducts of the CDH infant. This leads the authors to suggest that these abnormal biliary structures are the result of improper ductal plate remodeling at the hepatic hilum. In 3 of the BA patients there were some tubular bile ducts that probably are the result of delayed and abnormal attempt at ductal plate remodeling.

Bile Ducts, Intrahepatic↗

PubMed2003

Types of ethmoid sinus morphology on the basis of computed tomography examination.

The aim of the study was the application of computed tomography (CT) in the evaluation of types of ethmoid morphology. The material consisted of 197 CT examinations performed, using the Somatom AR.T (Siemens) CT scanner, in patients referred for CT for reasons other than sinus pathology. The examinations were performed in 2-mm contiguous axial scans. Ethmoid morphology was evaluated by means of classification into 3 types according to the degree of aeration and the relationship of the anterior ethmoid cells to the lacrimal sac on transversal scans. The most common was the II type (medium relationship to the lacrimal sac) found in 38.32% of the cases. Type III (large ethmoid sinus extending in front of the lacrimal sac) occurred in 32.49% of the patients, while the smallest sinus (Type I) was detected in the remaining 29.19% of the cases. In almost 1/5 of the cases asymmetry of the bilateral ethmoid anatomy was noted. It was concluded that CT examination was useful in the evaluation of ethmoid sinus morphology in respect to the lacrimal sac.

Adult↗

PubMed1999

Lymph node detection of head and neck squamous cell carcinomas by positron emission tomography with fluorodeoxyglucose F 18 in a routine clinical setting.

BACKGROUND: Accurate determination of lymph node involvement is a prerequisite for individualized therapy in patients with squamous cell carcinoma of the head and neck region. In a previous study, we showed that positron emission tomography (PET) with fluorodeoxyglucose F 18 with and without attenuation correction is superior to magnetic resonance imaging for this purpose in a scientific setting. OBJECTIVE: To evaluate the diagnostic accuracy of a shortened PET protocol (acquisition time, 20 minutes) in a routine clinical setting. DESIGN: The results of static, nonattenuation-corrected PET performed on patients in 2 bed positions starting 40 minutes after the intravenous injection of 370 MBq of fluorodeoxyglucose F 18 and the results of morphologic procedures (computed tomography and magnetic resonance imaging) were compared prospectively in 70 patients for lymph node staging. Postoperative pathologic findings served as a criterion standard. SETTING: An academic medical center. RESULTS: The diagnostic accuracy of PET for detecting "neck sides" with malignant involvement was superior to morphologic procedures, with a sensitivity and specificity of 87% and 94%, respectively, compared with computed tomographic values of 65% and 47% and magnetic resonance imaging values of 88% and 41%, respectively. CONCLUSION: A short PET protocol that is suitable for routine clinical use is superior to morphologic procedures (computed tomography and magnetic resonance imaging) for the detection of lymph node involvement in head and neck squamous cell carcinomas.

Academic Medical Centers↗

PubMed1996

Intraobserver, interobserver variation of sperm critical morphology: comparison of examiner and computer-assisted analysis.

OBJECTIVE: To examine intraobservational and interobservational variation in sperm critical morphology analysis between trained andrologists and a computer over the range of 0% to 15% normal forms. DESIGN: Retrospective. SETTING: Fertility center. PATIENTS: Twenty-four semen specimen slides were read five times in a randomized, blinded fashion by two andrologists and a computerized semen analyzer. Twenty-five samples were analyzed using a different stain and a centrifugation step. MAIN OUTCOME MEASURE: Sperm strict morphology. RESULTS: Mean average intraobserver deviation of normal forms was small (1.3% to 2.7%). Intraobserver deviation did not differ between andrologists, but both differed from the computer. Interobserver deviation for percent normal forms was similar for andrologists and computer. Mean average deviations were small over the variation was independent of the initial percent normal forms. The computer frequently evaluated significantly fewer cells than the andrologists. Updated software increased the number of cells read by the computer requiring more time than the andrologist. CONCLUSIONS: Trained andrologists and a computer determine sperm critical morphology similarly over the range of 0% to 15% normal forms. A single evaluation is highly predictive of multiple evaluations. Improvements in the speed of computer assessment are still necessary.

Diagnosis, Computer-Assisted↗

PubMed1999

[Computer-assisted analysis of sperm morphology in veterinary medicine].

The evaluation of spermatozoal morphology is an essential step to determine the fertility potential in male individuals. The method of computer-assisted morphometry provides an efficient tool to evaluate objectively morphological anomalies of the sperm head. This review describes the development and current status of morphometry systems and addresses the various problems associated with this method in veterinary medicine. Although there are some unanswered questions, a number of interesting results have been obtained. In all species investigated an individual influence on sperm head dimensions could be demonstrated. In the bull the extent of variability rather than absolute morphometric data is related to individual fertility. The method of computer-assisted morphometry will also help to develop well defined criteria for subjective evaluation of sperm morphology. Further research has to be directed towards the evaluation of the sperm mid-piece. The ultimate goal is the automatic determination of spermatozoal morphology.

Animals↗

PubMed1982

[Evaluation of left ventricular morphology and function by cardiac computed tomographic examination].

Usefulness of cardiac computed tomography (CT) in the evaluation of left ventricular (LV) morphology and function was studied in clinical practice. One hundred and forty-nine adult cases of various heart diseases were examined by GE scanner with ungated scans covering whole LV and ECG-gated scans. In gating examination, "long-axial" and "short-axial" slices were scanned and end-diastolic area (EDA), end-systolic area (ESA) and "mean" area (MA) were obtained in each slices. 1) With regard to LV morphology, wall thickening in HCM and wall thinning and mural thrombus in myocardial infarction were easily visualized. 2) LV "mean" volume (LVMV) was easily calculated from the sum of sliced LV volume of ungated scans. The LVMV was well correlated with end-diastolic volume (EDV) obtained by LV angiocardiography (LVG) (r = 0.91), though the former was somewhat smaller than the latter. EDV by CT obtained after the correction with MA/EDA from gating examination showed a better correlation (r = 0.95) and both EDV showed almost the same value. 3) LV ejection fraction (EF) was calculated by exchanging ESA/EDA to ESV/EDV in "long-axial" and "short-axial" gated slices, and "long-axial" EF, "short-axial" EF and mean of both were well correlated with LVEF of LVG (r = 0.73-0.79). 4) LVEF calculated from "long-axial" EDA and ESA by application of "area-length" method was also correlated with EF of LVG (r = 0.68), but these EDV and ESV were smaller than those of LVG due to shorter long-diameter of LV in CT. 5) LV muscle volume was calculated from sum of sliced muscle volumes of ungated scans covering LV, and LV mass was easily evaluated from LV muscle volume and specific gravity of LV muscle. This LV mass was well correlated with that of LVG (r = 0.90) and the absolute values were almost the same.

Adult↗

PubMed1991

Computer-assisted assessment of human sperm morphology: comparison with visual assessment.

OBJECTIVE: Sperm morphology classification was analyzed by the computer-assisted semen analysis equipped with the Morphologizer II (Cryo Resources Ltd., New York, NY) was compared with the traditional manual method. DESIGN, SETTING, PATIENTS: Fifty stained semen smears from men attending the infertility clinic of a tertiary referral institution were studied. MAIN OUTCOME MEASURES: Sperm head morphology was classified by the two methods into the following forms: normal, small oval, big oval, taper, and amorphous. RESULTS: Overall, the classifications of mean percent normal, small, and amorphous head forms were similar in the two methods. However, the differences between paired values obtained by the two methods were highly variable (range from -20% to +20%). The large differences between the methods were related to the large coefficients of variations present when classifying abnormal sperm morphology even by the same experienced technician. Only the percent normal spermatozoa could be classified by both methods with acceptable precision. In contrast, the variations in the morphometric analyses between the different semen smears were very small. CONCLUSIONS: There was no advantage of the morphologizer over the manual method in sperm morphology classification. The clinical value of morphometric parameters of spermatozoa has to be defined.

Humans↗

PubMedDate not supplied

The role of sperm morphology in assisted reproduction.

This article attempts to evaluate the value of sperm morphology in assisted reproduction by summarizing a recent structured literature review covering the topic. New developments in the field of sperm morphology with emphasis on computer evaluation of morphology and its latest clinical application are highlighted, as well as the correlation between sperm functional tests and sperm morphology. Based on the correlation between the sperm functional tests and sperm morphology, as well as the latter's proven value as a predictor in in-vitro fertilization, one can assume that sperm morphology reflects function, although based on definition it is not a sperm functional test per se. The evaluation of sperm morphology by strict criteria is a simple, cost-effective method and can be used to guide the clinician and scientist on a day-to-day basis to make sound clinical decisions.

Female↗

PubMed2004

Equivalence study of a dental anatomy computer-assisted learning program.

Tooth Morphology is a computer-assisted learning program designed to teach the anatomy of the adult dentition. The purpose of this study was to test whether Tooth Morphology could teach dental anatomy to first-year dental students as well as the traditional lecture. A randomized controlled trial was performed with forty-five first-year dental students. The students were randomly assigned to either the Tooth Morphology group (n=23), which used the computer-assisted learning program and did not attend lecture, or the lecture group (n=22), which attended the traditional lecture and did not use Tooth Morphology. The Tooth Morphology group had a final exam average of 90.0 (standard deviation=5.2), and the lecture group had a final exam average of 90.9 (sd=5.3). Analysis showed that the two groups' scores were statistically equivalent (p<0.05), with a priori equivalence bounds around the difference between the groups set at +/-5 points. It was concluded that Tooth Morphology taught the anatomy of the adult dentition as well as traditional lecture, as measured by exams. Based on the results of this study and student feedback, Tooth Morphology, in combination with interactive class meetings, has replaced the traditional dental anatomy lectures.

Adult↗