PubMed Health⌕ Search

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 253 records · Page 14Linked to original sources
PubMed2005

Cranial distraction for plagiocephaly: quantitative morphologic analyses of cranium using three-dimensional computed tomography and a life-size model.

The aim of this study was to analyze the morphologic changes of the craniofacial skeleton in synostotic plagiocephaly after cranial distraction. Preoperative and postoperative computed tomography scans were taken, and three-dimensional reconstruction was then performed. Three measurements were obtained: intracranial volume, volume of the middle cranial fossa, and length of the zygomatic arch. Intracranial volume reached values that were normal for a 2-year-old child postoperatively, and the discrepancy between left and right half volumes decreased over time. The discrepancy of the volume of the middle cranial fossa also decreased after surgery, and the asymmetry of the zygomatic arch improved significantly. Based on these objective findings, the authors believe that cranial distraction could favorably affect craniofacial dysmorphology of synostotic frontal plagiocephaly.

Brain↗
PubMed2001

ABC stenosis morphology classification and outcome of coronary angioplasty: reassessment with computing techniques.

BACKGROUND: The American College of Cardiology/American Heart Association (ACC/AHA) stenosis morphology classification (MC) stratifies coronary lesions for probability of success and complications after coronary angioplasty (PTCA). Modern computing techniques were used to evaluate the individual predictive value of MC in random PTCA cases. METHODS AND RESULTS: MC was attributed to the target lesions by consensus of 2 observers. The predictive value regarding procedural success (PS) and major adverse cardiac events (MACE) of MC was analyzed by conventional logistic regression analyses and by inductive machine learning models. The study was adequately powered for the methods applied with 325 target lesions of 250 cases. Overall, PS decreased and MACE increased from type A to type C lesions. Regression analysis identified no single factor as predictive. Logistic regression showed an error rate of 42%. Machine learning techniques achieved an individual predictive error of only 10%, which could be further reduced to 2% by addition of parameters. For PS, MC parameters showed a high ranking for building the model. For MACE, variables of the medical history showed more impact. CONCLUSIONS: MC per se cannot individually predict PS or MACE. However, when all MC parameters are integrated together with additional lesion-specific and history variables, a high individual predictive value can be achieved. This technique may be clinically helpful for risk stratification in the catheterization laboratory and improvement of classification systems in interventional cardiology.

Algorithms↗
PubMed1997

Morphologic assessment of abdominal aortic aneurysms by spiral computed tomographic scanning.

PURPOSE: The aim of this study was to seek a relationship between the morphologic features of abdominal aortic aneurysms and the feasibility of endoaortic grafting. METHODS: Between June 1995 and January 1996, 86 patients were prospectively studied with contrast-enhanced spiral computed tomographic scans, which provided 35 parameters concerning the aorta and iliac arteries. Four groups were established according to the diameter of abdominal aortic aneurysms: group A, 40 to 49 mm, 36 patients; group B, 50 to 59 mm, 26 patients; group C, 60 to 69 mm, 10 patients; and group D, greater than 70 mm, 14 patients. RESULTS: There was a correlation between the diameter and length of the aneurysm (p < 0.0001) and between aneurysm diameter and length of the proximal neck (p < 0.001). Presence of a proximal neck or a distal neck was more frequent in groups A and B than in groups C and D (p < 0.01). The feasibility of endovascular grafting was estimated at between 50% and 61.6% and was higher in groups A and B than in groups C and D (p < 0.01). CONCLUSIONS: This study has shown an inverse relationship between the diameter of the aneurysm and the length of the aortic neck (correlation coefficient, -0.3640, p < 0.001). The diameter of an aneurysm was the most useful of the 31 parameters measured in predicting the feasibility of endoaortic grafting, estimated at 71% for aneurysms less than 60 mm in diameter and 37.5% for aneurysms greater than 60 mm in diameter (p < 0.01).

Aged↗
PubMed1999

Morphological characterization of ejaculated cynomolgus monkey (Macaca fascicularis) sperm.

The aim of this study was to give reference values for the frequency of morphological sperm abnormalities present in the semen from non-experimental cynomolgus monkeys as well as for the dimensions of sperm heads. Spermatozoa from the liquid portion of electroejaculates from 14 cynomolgus monkeys were air-dried as smears, fixed, and stained with Harris's Haematoxylin and subjected to visual analysis of morphology and computer-aided analysis of ten morphometric variables. The majority (83%) of sperm were morphologically normal. Tail defects were the most common (11%), and showed the highest variation between individuals, the values ranging between 4 and 23%. Head abnormalities consisted of large, tapering, and amorphous forms but were not frequent (0.4%), the values ranging between 0 and 1.3%. Midpiece imperfections were found in all the individuals; the mean percentage was 5%, and the range varied between 3 and 9%. Tail plus midpiece was the only multiple abnormality observed, with a mean value of 1.5% and a range between 0 and 8%. The majority of these double defects consisted of a coiled tail together with a coiled midpiece. Mean values for the morphometric parameters characterizing sperm heads were as follows: area 17.2 microm2, perimeter 15.2 microm, length 5.8 microm, width 4.0 microm, L/W ratio 1.5, gray-level 98, ellipticity 0.2, first shape factor 0.9, second shape factor 1.4, and third shape factor 1.1. Overall coefficients of variation for the majority of parameters were below 7%, showing the great homogeneity in the dimensions of cynomolgus sperm heads. Most useful parameters for sperm characterization, according to their low variability, were perimeter, length, width, L/W ratio, and shape factors. Differences in these parameters were, however, observed between monkeys.

Animals↗
PubMed1985

Computed tomography of temporal bone pneumatization: 1. Normal pattern and morphology.

The pneumatization of 141 "normal" temporal bones on computed tomography (CT) was evaluated in 100 patients (age range, 6-85 years). Because of the controversy surrounding the sclerotic squamomastoid (mastoid), temporal bones with this finding were discarded. A CT index of pneumatization was based on the pneumatized area and the number of cells seen within a representative scanning section. Results suggest that squamomastoid pneumatization follows the classic normal distribution and does not correlate with age, gender, or laterality. A high degree of symmetry was found in 41 patients who had both ears examined. In 35% of all temporal bones, the petrous apex was pneumatized, concordant with the findings of other investigators. Pneumatization extending into other regions of the temporal bone corresponded linearly with squamomastoid pneumatization. Air-cell configuration was variable. Air-cell size tended to increase progressively from the mastoid antrum. The scutum "pseudotumor" appearance caused by incomplete pneumatization was seen frequently, and should not be mistaken for mastoiditis or an osteoma. Thick sections producing partial-volume effect may also produce this spurious finding. Therefore, when searching for mucosal thickening due to mastoiditis, large air cells should preferably be analyzed.

Adolescent↗
PubMed2004

Traditional detection versus computer-controlled multilevel analysis of nuclear structures from donated human embryos.

BACKGROUND: Multinuclearity is known to correlate with decreased implantation and pregnancy rates. Thus, a valid detection of nuclear structures especially among otherwise good quality embryos may be of great importance in order to improve clinical outcome. In this study, we have compared traditional manual microscopic analysis with computer-controlled multilevel morphological assessment for analysis of nuclear status in human embryos. METHODS: In total, 84 donated 2- and 4-cell embryos with < or = 20% fragmentation from patients referred for IVF or ICSI treatment were included. Mono- and multinuclearity was recorded using traditional analysis as well as computer-controlled multilevel analysis of each intact embryo. Subsequently, the embryos were separated into individual blastomeres to assess the number of nuclear structures. All nuclear structures were fixed and stained for DNA. RESULTS: There was no significant difference (P = 1.0) between embryonic nuclear status detected by computer-controlled analysis of the intact embryos and of the separated blastomeres. Additionally, 100% of the fixed nuclear structures contained DNA. However, using traditional morphological analysis, significantly more embryos (26%) had incorrect nuclear status detected (P = 0.002). Further, the presence of <10% embryonic fragmentation had no impact on the correct detection of nuclear structures using the multilevel analysis. For embryos with 11-20% fragmentation, 86% of the nuclear structures detected in the separated blastomeres were found in the intact embryos. The mean diameter of nuclear structures was significantly decreased from 22.1 microm in mononucleate 2-cell embryos to 18.7 microm in mononucleate 4-cell embryos (P < 0.001). CONCLUSION: The results of this study indicate that the use of computer-controlled multilevel morphological analysis can improve the detection of nuclear structures in human embryos.

Adult↗
PubMed1983

Ultrasound, computed tomography and endoscopic retrograde cholangiopancreatography in the morphologic diagnosis of pancreatic disease.

From February to November 1981 the diagnostic relevance of ultrasound (US), computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP) was compared prospectively in 75 patients with suspected pancreatic disease. Final diagnosis was confirmed by autopsy, surgery, clinical course, and further laboratory data. Thus it was possible to exclude pancreatic disorders in 32 patients. By ERCP we diagnosed all tumors; sensitivity was 100%. Sensitivity of US and CT were 63% each. In five cases US made the false positive diagnosis" pancreatic malignant tumor" (specificity 93%), CT and ERCP in two cases (specificity 97% each). In chronic pancreatitis specificity of US and ERCP were 100% and specificity of CT was 98%. Sensitivity of ERCP amounted to 93%, CT and US revealed 74% and 52%, respectively. We conclude that ERCP is the best morphologic diagnostic tool in differentiating chronic pancreatitis from pancreatic carcinoma. US is a good screening method and CT reveals good diagnostic results in acute pancreatitis.

Adult↗
PubMed1975

The use of an image analysing computer for the quantitation of red cell morphological characteristics.

Measurements of integrated optical density and projected area of red cells have been made on Romanowsky-stained blood films from 25 subjects using an image analysing computer. Close correlation was observed between mean cell projected area and MCV and between mean cell integrated optical density and MCH. Mean values for the quotient of cell integrated density/cell projected area (mean cell colour density) correlated with MCHC. Varieties of cell area and colour density correlated subjectively with anisocytosis and anisochromasia, and histograms of these parameters demonstrated dual populations. The clinical application of these findings is discussed.

Anemia↗
PubMed1991

Quantitative evaluation of the tumour-stroma border by exponential regression analysis.

The architecture of the tumour margin is an essential feature for the histological diagnosis of certain neoplasms. In a previous study we have shown by computer simulations, that the degree of tumour cell motility and proliferation influences qualitative morphological criteria of the tumour border. Here we propose a method for an objective, quantitative description of the tumour cell distribution at the tumour-stroma border. 100 morphological patterns generated by computer simulation with different preset degrees of motility and proliferation were evaluated. On a measuring path starting at the most peripheral cell and going towards the tumour centre, the density of tumour cells for each distance from the tumour margin was calculated from the number of cells within a 5 x 5 matrix around each measuring point. An exponential regression function was adapted to the measured density distribution. The parameters of the regression curve and 'the goodness of fit' were tested for correlation with the preset simulation parameters. It was found that the degree of motility and proliferation can be deduced from the quantitative descriptors of the tumour margin (linear regression of the preset values and of the values estimated from the morphological analysis: r = 0.903; t = 20.7; P less than 0.001). Besides the evaluation of computer-simulated morphological patterns, the same measuring procedure can also be applied to histological slides of melanocytic skin tumours using automated image analysis.

Cell Division↗
PubMed1990

Computer aided time-lapse video analysis of hepatocyte morphology during adhesion to cellulose membranes.

An investigation was performed to demonstrate that time-lapse cinematography and computer aided video analysis of cell morphology is suitable to study and compare the characteristics of hepatocytes during the adhesion process to membranes. We chose to compare ordinary cellulose Cuprophan membranes and membranes coated with collagen or fibronectin. Striking differences between uncoated cellulose and fibronectin or collagen coating were seen in the cell count per square millimeter and adhesion behaviour. On the investigated uncoated Cuprophan the hepatocytes were found to attach but not to spread whilst on collagen coated Cuprophan most of the cells spread spherically, and on fibronectin coated membranes most of the cells flattened spherically or polygonally. Time-lapse video microscopy seems to be a valuable technique for assessing the morphologic behaviour of cells in a detailed and quantitative manner in order to improve the hepatocyte culture technique in bioreactors for hybrid systems.

Animals↗
PubMedDate not supplied

[Computer-assisted instruction in the field of morphology].

Visiting the image collections of normal and pathological morphology, available with free access on the World Wide Web (www), represents a vast source of extremely valuable material for both teaching and documentation in research activities. The aim of this paper is to provide a brief overview of the www facilities, which is gradually structured at the conceptual level. This overview ranges from the exploration of various topics in medical sciences/morphology, till the concrete aspects revealed by the construction and utilization of image libraries, designed for internal use, in accordance with certain systematic criteria. Examples from normal and pathological morphology illustrate the principles envisaged by the elaboration of such libraries.

Computer-Assisted Instruction↗
PubMedDate not supplied

Assessment of cardiac function using multidetector row computed tomography.

In patients with suspected or documented heart disease, a precise quantitative and qualitative assessment of cardiac function is critical for clinical diagnosis, risk stratification, management and prognosis. Cardiac CT is increasingly being used in diagnosis of coronary artery disease. Initially multi-detector row computed tomography (MDCT) was used chiefly for detecting coronary artery stenosis and assessment of cardiac morphology. Electron beam computed tomography has been shown to provide a highly accurate ejection fraction (+/-1%), with 50 ms image acquisition per image. Retrospective electrocardiographic gating allows for image reconstruction in any phase of the cardiac cycle. Thus, end systolic and end diastolic images can be produced to assess ventricular volumes and function. Despite lower temporal resolution than electron beam computed tomography, the ability of MDCT to assess ejection fraction is preserved. In the assessment of cardiac function, MDCT has been shown to be in good agreement with echocardiography, cineventriculography, single photon emission computed tomography and magnetic resonance imaging. The fast technical development of scanner hardware along with multisegmental image reconstruction has led to rapid improvement of spatial and temporal resolution and significantly faster cardiac scans. The same data that is acquired for MDCT angiography can also be used for evaluation of cardiac function. Considering contrast media application, radiation exposure, and limited temporal resolution, MDCT solely for analysis of cardiac function parameters seems not reasonable at the present time. However, because the data is already obtained during coronary evaluation, the combination of noninvasive coronary artery imaging and assessment of cardiac function with MDCT is a suitable approach to a conclusive cardiac workup in patients with suspected coronary artery disease. MDCT seems suitable for assessment of cardiac function by MDCT when results are held in comparison to magnetic resonance imaging as the reference standard. Given the radiation dose and contrast requirement, referring a patient to MDCT only for evaluation of function is not warranted, but rather adds important clinical information to the already acquired data during retrospective triggering for MDCT angiography.

Contrast Media↗
PubMed1999

Three-dimensional computer-assisted simulation combining facial skeleton with facial morphology for orthognathic surgery.

The purpose of this study was to use a 3-dimensional (3D) computer-aided design (CAD) simulation system to plan surgical procedures and predict postoperative changes in orthognathic surgery patients. A computer-generated imaging model was developed by combining a 3D reconstructed cephalometric skeletal image and a laser-scanned facial surface image. Moreover, postoperative data were studied and linked to the simulator model for programming and executing simulated surgical procedures. Interactive editing capabilities allow surgeons to operate CAD surgical simulation, and predicted results can be presented graphically and numerically. The results indicate that the integration of 3D images and CAD techniques have a potential for simulating surgery and providing graphic information to patients in obtaining an informed consent.

Adult↗
PubMed1984

Fluctuations in T-wave morphology and susceptibility to ventricular fibrillation.

Susceptibility of the ventricles to fibrillation has been related to the degree of spatial inhomogeneity in the repolarization process. We studied the pattern of beat-to-beat fluctuations in ventricular repolarization processes in order to determine whether a relationship also exists between the temporal variability of ventricular repolarization and susceptibility to ventricular fibrillation. We used the morphology of the T-wave recorded in surface and epicardial leads as a measure of the ventricular repolarization process. The Ventricular Fibrillation Threshold (VFT) was used as the standard measure of cardiac susceptibility to fibrillation. In dog experiments, T-wave morphologic indices were computed on 1,024 sequential beats. Histogram, autocorrelation and power spectrum analyses were performed on the sequence of T-wave morphologic indices. A series of 27 experiments were performed on 20 dogs in which VFT was reduced by several different interventions--hypothermia, tachycardia and coronary artery ligation. For all three interventions we observed the same characteristic change in the pattern of T-wave morphology fluctuations. In particular, we found that as the VFT was reduced, a pattern of T-wave alternans developed. This pattern was generally not detectable by visual inspection of the ECG. It was, on the other hand, easily quantified in terms of a T-wave alternans index (TWAI) which we computed from the power spectrum of the T-wave fluctuations. In 26 of the 27 experiments, measured VFT decreased (p less than .001); in 20 of these experiments the TWAI computed from the surface ECG increased (decreased) when VFT decreased (increased) (p less than .01). In 17 experiments epicardial electrograms were recorded. In 16 of these experiments VFT decreased (p less than .001). In 16 of these 17 experiments TWAI computed from the epicardial ECG increased (decreased) when the VFT decreased (increased) (p less than .001). We conclude that statistical analysis of fluctuations in ECG complex morphology may provide a sensitive probe of ventricular vulnerability to fibrillation.

Animals↗
PubMed2003

Structuring parameters for assessment of bone quality using a morphological filter and star volume analysis: structuring property in the cancellous bone of the human femoral head.

This study examines structuring parameters for the assessment of bone quality based on the relationship of bone strength to the trabecular structure or bone mineral density (BMD). Thirty-nine human cancellous bone blocks sampled from resected Ward's triangle area were investigated. The trabecular bone pattern of each bone block was binarized into its corresponding trabecular skeletal pattern using computed radiography with a morphological filter. Every binarized trabecular skeletal pattern was quantified to find the trabecular skeletal pixel percentage (SkP = volume parameter of trabecular skeletal signal component) and skeletal star volume (Vt = connection parameter of trabecular skeletal structure). After BMD and elasticity for each bone block was measured by dual X-ray absorptiometry and the breaking test, the correlations to SkP and Vt were determined. In addition, an attempt was made to detect changes of the trabecular structure in the Ward's triangle area of the femoral head after patients had received treatment for osteoporosis. This evaluation used the structuring parameters SkP and Vt. The results showed that the larger the BMD value, the greater the elasticity, although some samples with similar BMD values had considerably different elasticities. With increased Vt values the trabecular skeletal pattern that had horizontal skeletal elements orientated perpendicular to the loading direction showed higher elasticity. No correlation between SkP and either elasticity or BMD was observed in either the subset (sequential images of morphological filter) or sumset images (combined with subset images). On the other hand, the correlation coefficient between Vt and elasticity was similar to that between BMD and elasticity for subset image ( n = 6). For sumset images (3-6 and 4-7), the correlation coefficient of Vt was equal or higher than that of BMD and the connectivity of the trabecular skeletal structure was more closely linked to bone strength as compared to BMD. Therefore, it was concluded that because no high correlation could be detected between Vt and BMD, BMD and the connectivity of trabeculae are independently related to bone strength. In addition, this method was used to evaluate patients after treatment for osteoporosis, and noticeable changes were seen in the bone trabecular skeletal structure in the Ward's triangle area of the femoral head. In reference to these clinical images, variations in SkP and Vt were quantitatively assessed. These results suggest that the SkP and Vt obtained using computed radiography, morphological filter, and star volume analysis are useful structuring parameters for the assessment of bone quality.

Aged↗
PubMed1986

Three-dimensional wrist imaging: evaluation of functional and pathologic anatomy by computer.

The wrist has been studied morphologically and functionally using advanced technology. The osseous morphology of the wrist was investigated by computed tomography and surface reconstruction software. The functional behavior of the wrist in motion was studied using electromagnetic tracker technology. Three-dimensional imaging from CT scans is emerging as a research tool for the study of gross surface morphology, especially for osseous structures. One of the most demanding applications of this technology lies in the human wrist, because of its small size and inherent complexity. We have demonstrated some of the potential of computer graphics and three-dimensional surface reconstructions in the wrist for patients with osseous abnormalities. Acquisition of six-degree-of-freedom kinematic data to describe carpal motion has been made possible by new electromagnetic tracker technology. Analysis of these data in human wrist experiments revealed that the instantaneous center of rotation was not fixed in the head of the capitate, as was previously thought.

Adult↗
PubMed1977

A computer-based videodensitometric system for studying banded human chromosomes illustrated by the analysis of the normal morphology of chromosome 18.

A computer-based, high-resolution, high-speed system is described for the digitization of television images of human G-banded chromosomes, on-line directly from a microscope. The digitized data are processed by a computer to determine the total length and centromere index of individual chromosomes and to obtain an integrated density profile representing the band pattern. The density profile is reduced by the computer to a series of dark and light bands, each with a defined position, width, and density. The results are displayed by the computer on a television monitor in a form that simulates routine laboratory preparations and that allows cytogenetic inspection. The system is easy to operate, and it includes a wide range of options for operator interaction to ensure reliability. The results of the computer analysis of the no. 18 chromosomes from five cells from each of 10 different persons demonstrated the usefulness of the system for detecting, measuring, and analyzing individual bands in human populations and its application to establishing band patterns of chromosomes in different states of contraction.

Azure Stains↗