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 325 records · Page 18Linked to original sources

PubMed1990

Morphology of the condyles and mandibular fossa as seen by computed tomography.

Computed tomography allows detailed three-dimensional examination of the hard and soft tissue of the temporomandibular joint. The morphology of the mandibular fossa and the condyles together with the horizontal and vertical condylar inclinations was determined in 25 patients with temporomandibular joint dysfunction and 29 controls by use of axial and coronal computed tomography projections. The shape of the condyle was evaluated according to its general appearance. The temporomandibular joint measurements obtained by computed tomography were in good agreement with morphologic studies performed on dry skulls and autopsy material.

Adolescent↗

PubMed2006

[Application of flow cytometry to the evaluation of semen quality].

OBJECTIVE: To evaluate the role of flow cytometry in semen assessment. METHODS: Semen samples from 104 infertile male patients (as the case group) and 10 fertilized donors (as the control group) were analyzed for the volume of ejaculate and sperm concentration, motility and atypical morphology by computer-assisted semen analysis (CASA), the viability, chromatin structure and mitochondrial membrane potential (MMP) of the sperm stained by SYBR-14/PI, AO and JC-1 respectively, and assessed with flow cytometry. The results were analyzed through SAS software. RESULTS: U tests indicated that the semen from the infertile patients had not only lower concentration (U = 2.51, P = 0.0143), lower motility (U = 3.44, P = 0.001) and higher rate of atypical morphology (U = -5.88, P < 0.0001), but also lower viability (U = 4.72, P < 0.0001), MMP (U = -2.53, P = 0.0309), and chromatin integrity (alpha t: U = -3.82, P = 0.0003; SD alpha t: U = -3.98, P = 0.0001; COMP alpha t: U = -3.57, P = 0.0005). The multiple stepwise regression analysis revealed that sperm motility was positively correlated with sperm membrane integrity (t = 1.66, P = 0.1016), sperm MMP (t = 3.33, P = 0.0014) and sperm acrosome integrity (t = 3.24, P = 0.0019), while sperm MMP was negatively correlated with the rates of sperm neck and tail defects (t = -3.44, P = 0.001). CONCLUSION: Flow cytometry plays a significant role in the evaluation of the quality of human sperm, and can be adopted as a useful tool in the diagnosis and treatment of male infertility.

Adult↗

PubMed2002

Lumbar pedicle morphology in the immature spine: a three-dimensional study using spiral computed tomography.

STUDY DESIGN: A cross-sectional study was conducted. OBJECTIVE: To investigate the pediatric pedicle morphology with the help of modern computed tomography technology. SUMMARY OF BACKGROUND DATA: The use of pedicular screws recently has gained popularity because of their ability to provide three-dimensional correction of spinal deformity. Extensive work has been published on the pedicle morphology of the adult and adolescent thoracolumbar spine. Less is known about the pedicle morphology of children. METHODS: A total of 21 patients ages 5 to 10 years underwent standard spiral computed tomography of the abdomen. The patients were grouped according to age: Group 1 (5 to 8 years of age) and Group 2 (9 to 10 years of age). Images were reformatted, and multiplanar reconstructions were used to attain images of lumbar pedicles on sagittal, coronal, and transverse planes. The measurements included the inner and outer pedicle diameters on the transverse plane, the pedicle angle on both the transverse and sagittal planes, and pedicle length. RESULTS: The smallest pedicle lengths were 24 mm for Group 1 and 25 mm for Group 2. When the average values were considered, the smallest lengths were at L5 and the longest at L3. The smallest diameter was at L1 (2.3 mm for Group 1 and 3 mm for Group 2), whereas L5 had the largest diameter (6.17 mm for Group 1 and 8.72 mm for Group 2). In the transverse plane, the pedicle angle increased from L1 to L5 in both groups. In the sagittal plane, the angulations followed an opposite trend. CONCLUSIONS: The inner transverse diameter of the lumbar pedicle, particularly in young children, is smaller than previously reported. Insertion of screws currently available commercially screws seems to be safe in the L4-L5 pedicles of children ages 5 to 8 years, and in the L3-L5 pedicles of older children. Custom-made screws might be considered for upper levels for safe application.

Bone Screws↗

PubMed2005

Acute adrenal failure as the heralding symptom of primary antiphospholipid syndrome: report of a case and review of the literature.

Acute adrenal failure is a potentially fatal condition if overlooked. Occasionally, acute adrenal insufficiency may ensue from bilateral adrenal haemorrhage in patients with known antiphospholipid syndrome (APS). APS is characterized by recurrent arterial and venous thrombosis, pregnancy complications and detection of autoantibodies to phospholipids. This syndrome may be associated with non-organ specific diseases (e.g. connective tissue disorders) or with malignancies, but it may also appear in isolated form (primary APS). In a very few cases the heralding manifestation is given by adrenal failure. We report here a 63-year-old man presenting with acute adrenal insufficiency as the opening clinical manifestation of an APS. We also carried out a computer-aided search of the literature to identify all cases of primary adrenal failure as the first-recognized expression of a primary APS, a condition that not so infrequently may be tackled by endocrinologists. 20 patients fulfilled the inclusion criteria. The great majority of them were males (75%) with a mean age of 42 years. Abdominal pain was present in 14 patients, followed by fever (13 patients) and hypotension (12 patients). The main morphological findings by computed tomography or magnetic resonance were consistent with bilateral adrenal haemorrhage in 11 patients. Lupus anticoagulant was present in all of the 19 tested patients. Our observations emphasize the importance in the assessment of clotting times, and possibly of antiphospholipid antibodies, in all patients with diagnosis of rapidly progressive adrenal failure and concurrent abdominal pain.

Acute Disease↗

PubMed2002

Renal atrophy in atherosclerotic renovascular disease: gradual changes 6 months after successful angioplasty.

OBJECTIVE: To assess renal morphology using spiral computed tomographic angiography (CTA) before and 6 months after angioplasty of unilateral atherosclerotic renal artery stenosis (RAS). METHODS: Spiral CTA scans from 14 hypertensive patients (7 men; mean age 57.4 +/- 13.1 years) with significant RAS were performed before and 6 months after angioplasty; renal length, mean cortical thickness (MCT), cortical area (CA), and medullary length (ML) were measured from the axial slices in the 14 contralateral and 14 poststenotic then revascularized kidneys. Blood pressure, creatinine clearance, and number of antihypertensive drugs were analyzed. RESULTS: At 6 months, the systolic blood pressure was significantly reduced (p=0.007), but the number of antihypertensive drugs and the creatinine clearance did not change significantly. Most morphological parameters before and after angioplasty were different in the contralateral versus poststenotic kidneys (renal length, p=0.01; MCT, p=0.01; ML, p=0.03; CA, p=0.008). After angioplasty, there was an 11% drop in cortical atrophy associated with a mean 4-mm increase in medullary length in the poststenotic/revascularized kidneys. The contralateral kidneys exhibited corticomedullary thinning after angioplasty. CONCLUSIONS: In atherosclerotic renal disease, cortical thinning could be a useful timesaving marker to assess the significance of the lesion and to evaluate associated distal lesions. The favorable blood pressure outcome supports the existence of reversible ischemic lesions, particularly in the medulla. Angioplasty appears to be useful for the poststenotic kidney, according to the morphological study.

Adult↗

PubMed1999

Model-based morphological segmentation and labeling of coronary angiograms.

A method for extraction and labeling of the coronary arterial tree (CAT) using minimal user supervision in single-view angiograms is proposed. The CAT structural description (skeleton and borders) is produced, along with quantitative information for the artery dimensions and assignment of coded labels, based on a given coronary artery model represented by a graph. The stages of the method are: 1) CAT tracking and detection; 2) artery skeleton and border estimation; 3) feature graph creation; and iv) artery labeling by graph matching. The approximate CAT centerline and borders are extracted by recursive tracking based on circular template analysis. The accurate skeleton and borders of each CAT segment are computed, based on morphological homotopy modification and watershed transform. The approximate centerline and borders are used for constructing the artery segment enclosing area (ASEA), where the defined skeleton and border curves are considered as markers. Using the marked ASEA, an artery gradient image is constructed where all the ASEA pixels (except the skeleton ones) are assigned the gradient magnitude of the original image. The artery gradient image markers are imposed as its unique regional minima by the homotopy modification method, the watershed transform is used for extracting the artery segment borders, and the feature graph is updated. Finally, given the created feature graph and the known model graph, a graph matching algorithm assigns the appropriate labels to the extracted CAT using weighted maximal cliques on the association graph corresponding to the two given graphs. Experimental results using clinical digitized coronary angiograms are presented.

Algorithms↗

PubMed1993

Comparison of computed tomography with radiography as a noninvasive diagnostic technique for chronic nasal disease in dogs.

Computed tomography was evaluated as a noninvasive technique for the diagnosis of chronic nasal disease in dogs. Computed tomographic images, radiographs, and histopathologic findings were compared in 11 dogs with chronic nasal disease. Definitive diagnosis was made following traumatic nasal flush, exploratory surgery, or necropsy. The study included 8 dogs with intranasal tumors, 2 dogs with bacterial rhinitis (Pasteurella sp), and 1 dog with mycotic rhinitis (Aspergillus sp). Computed tomography was superior to radiography in defining the extent of the disease process and in differentiating infectious rhinitis from nasal neoplasms. It defined lesions in the palate, nasopharyngeal meatus, maxillary sinus, caudal ethmoturbinates, and periorbital tissues that were difficult to demonstrate by use of conventional radiography. Tumors appeared as space-occupying lesions that obliterated the turbinates, caused deviation of the nasal septum, and eroded bone. Rhinitis appeared as a cavitating lesion that spared the paranasal sinuses, thickened and distorted the turbinates, and widened the meatus. Although morphologically distinct on computed tomographic images, infectious rhinitis and nasal neoplasms could not be differentiated by attenuation measurements or degree of contrast enhancement. Computed tomography appeared to be a reliable, noninvasive technique for the diagnosis of chronic nasal disease in dogs, and a promising alternative to diagnostic techniques currently in use.

Animals↗

PubMed1988

"DMS," a computer-assisted system for quantitating motility, the dynamics of cytoplasmic flow, and pseudopod formation: its application to Dictyostelium chemotaxis.

A computer-assisted Dynamic Morphology System (DMS) is described that allows the rapid quantitation of more than 30 parameters of motility and dynamic morphology for up to 40 amebae in parallel. This system also generates "difference pictures" for characterizing the dynamics of pseudopod formation. A 3-D DMS is described, and application of DMS to problems of motility and chemotaxis in normal and mutant cells of Dictyostelium discoideum is reviewed.

Chemotaxis↗

PubMed1998

Ultrasonography versus computed tomography in evaluation of the femoral trochlear groove morphology: a pilot study on healthy, young volunteers.

The aim of the study was to verify the efficacy of ultrasonography (US) in evaluating the morphology of normal trochlea, especially the sulcus angle and the trochlear depth, in comparison with computed tomography (CT) (gold standard). The knees of 11 asymptomatic volunteers were subjected to US and CT evaluation of the same section planes and the results were compared. For statistical evaluation Spearman's correlation coefficient analysis was used. A statistically significant correlation was found between the two diagnostic procedures (sulcus angle: r = 0.820; trochlear depth: r = 0.802; Spearman's correlation coefficient) and the intra-observer variability for the US measurements (sulcus angle: r = 0.966; trochlear depth: r = 0.914; Spearman's correlation coefficient). The mean value of sulcus angle and trochlear depth was 132 degrees and 5.6 mm, respectively, similar to those reported in the literature. We conclude that evaluation by US of both sulcus angle and trochlear depth is as reproducible and sensitive as that performed with CT.

Adolescent↗

PubMed2006

Computational modeling of arterial wall growth. Attempts towards patient-specific simulations based on computer tomography.

The present manuscript documents our first experiences with a computational model for stress-induced arterial wall growth and in-stent restenosis related to atherosclerosis. The underlying theoretical framework is provided by the kinematics of finite growth combined with open system thermodynamics. The computational simulation is embedded in a finite element approach in which growth is essentially captured by a single scalar-valued growth factor introduced as internal variable on the integration point level. The conceptual simplicity of the model enables its straightforward implementation into standard commercial finite element codes. Qualitative studies of stress-induced changes of the arterial wall thickness in response to balloon angioplasty or stenting are presented to illustrate the features of the suggested growth model. First attempts towards a patient-specific simulation based on realistic artery morphologies generated from computer tomography data are discussed.

Aorta↗

PubMed2005

Trabecular architecture of lumbar vertebral pedicle.

STUDY DESIGN: Investigation on architecture of lumbar pedicle. OBJECTIVE: To determine morphological properties of pedicular cancellous bone. SUMMARY OF BACKGROUND DATA: Many researchers have been stimulated to study trabecular architecture by improvements in stereological technology. Although the structure of vertebral cancellous bone has been well studied in the literature, no information is available about the architecture of pedicular cancellous bone. METHODS: Eight cadaveric L3 lumbar vertebrae were harvested. After collecting the bone mineral density (BMD) data on the vertebrae, pedicle isthmuses were removed from the vertebral bodies using a reciprocal hand saw. The BMD measurements were done on the dissected pedicle isthmus specimens. All the specimens were then analyzed using a micro-computed tomography unit. Morphologic parameters of trabecular bone were calculated. RESULTS: Bone volume was found as 0.209 +/- 0.046, whereas Tb.Th, Tb.Sp, and Tb.N were found to be 0.201 +/- 0.035 mm, 0.930 +/- 0.123 mm, and 1.098 +/- 0.136 mm(-1), respectively. Connectivity density and structure model index were observed to be 3.135 +/- 0.918 mm(-3), 0.37, whereas degree of anisotropy value was 1.241 +/- 0.093. Vertebral BMD could explain 63% of variance in bone density of a pedicle isthmus. CONCLUSIONS: The structure of the pedicular cancellous bone is somewhat different from that of vertebral body. The trabecular architecture within the pedicle isthmus is isotropic and plate-like. The thickness and number of the trabeculae were greater than those of vertebral trabeculae. Decrease in the bone volume with age is mainly by thinning of the trabeculae and increasing in trabecular spacing, but not by loss of mass.

Adult↗

PubMed1988

Quantitative morphology and synaptology of cerebellar glomeruli in the rat.

Computer-assisted stereological and quantitative morphological approaches were used to analyse cerebellar glomeruli of the "simple type" in serial ultrathin sections. It was found that, of the total volume (110-200 micron3) of the glomeruli studied, 53% was occupied by granule cell dendrites, 34% by mossy terminal and 13% by Golgi axons. None of the four analysed glomeruli contained Golgi cell dendrites. The mossy terminals that were studied received, on the average, 53 granule cell dendrites. All of the dendrites originated from different granule cells and all made synaptic contacts with mossy terminal. However only about 60% of granule cell dendrites made synapses with Golgi axons. The surface of the mossy terminals occupied by synaptic junctions, was found to be 5.4-5.5%. Each granule cell dendrite emitted 3-5 terminal protrusions ("dendritic digits"). Each digit receives one or more synaptic contact from either the mossy terminal (67% of all digits), or from Golgi axon varicosities (25%). Only about 8% of all digits were contacted synaptically by both types of axonal terminals. All of the dendritic digits that were observed made synaptic connections. Each digit was, on the average, connected by symmetric attachment plaques to 4 neighbouring digits. Three-dimensional reconstructions of mossy terminal and some of contacting granule cell dendrites demonstrated that the dendrites curved around the central mossy terminal and were much longer than expected from earlier Golgi-impregnation studies. In addition to mossy terminals and Golgi axons, an axon terminal of small calibre that contained large, empty, spheroid vesicles were occasionally observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1997

Functional impairment in fibrosing alveolitis: relationship to reversible disease on thin section computed tomography.

Thin-section computed tomography (CT) provides a reproducible method of quantifying global disease extent and can also discriminate between fibrotic disease, with predominance of reticular abnormalities, and reversible inflammatory cell infiltration, shown as ground-glass attenuation. The aim of this study was to determine whether functional impairment varied according to the presence of ground-glass attenuation on CT, independently of extent of disease on CT, demographic factors, smoking history, therapeutic status, and the type of fibrosing alveolitis (lone cryptogenic fibrosing alveolitis (CFA) versus fibrosing alveolitis associated with systemic sclerosis (FASSc)). Patients with concurrent emphysema on CT (n = 16) and FASSc patients with end-stage pulmonary hypertension (n = 5) were excluded. One hundred and eleven patients were studied (CFA, n = 54; FASSc, n = 57). The severity of functional impairment did not vary independently with the presence of predominant ground-glass attenuation, mixed appearance and predominant reticulation on CT. In 34 treated patients undergoing serial CT scanning, the severity of functional impairment did not differ independently between patients with and without regression of ground-glass attenuation at follow-up. We conclude that the severity of functional impairment does not discriminate between inflammatory and fibrotic disease in fibrosing alveolitis, as judged by initial and serial computed tomographic scanning, after adjustment for the morphological extent of disease on computed tomography.

Female↗

PubMed1994

Morphological evolution through complex domains of fitness.

Computer simulated phenotypic walks through multi-dimensional fitness-landscapes indicate that (i) the number of phenotypes capable of reconciling conflicting morphological requirements increases in proportion to the number of manifold functional obligations an organism must perform to grow, survive, and reproduce, and (ii) walks over multi-task fitness-landscapes require fewer but larger phenotypic transformations than those through single-task landscapes. These results were determined by (i) simulating a "morphospace" containing 200,000 phenotypes reminiscent of early Paleozoic vascular sporophytes, (ii) evaluating the capacity of each morphology to perform each of three tasks (light interception, mechanical support, and reproduction) as well as the ability to reconcile the conflicting morphological requirements for the four combinatorial permutations of these tasks, (iii) simulating the walks obtaining all phenotypic maxima or optima within the seven "fitness-landscapes," and (iv) computing the mean morphological variation attending these walks. The results of these simulations, whose credibility is discussed in the context of early vascular land-plant evolution, suggest that both the number and the accessibility of phenotypic optima increase as the number of functional obligations contributing to total fitness increases (i.e., as the complexity of optimal phenotypes increases, the fitnesses of optima fall closer to the mean fitness of all the phenotypes under selection).

Biological Evolution↗

PubMed1999

Availability of sperm examination for male reproductive toxicities in rats treated with boric acid.

Sperm morphological examination, computer-assisted sperm analysis (CASA) and histopathologic examination of the testis and epididymis were performed for male rats treated orally with boric acid for 3 weeks at dosage levels of 50, 150 and 500 mg/kg/day, and treated males were mated with untreated females. None of the males treated with 500 mg/kg/day could impregnate untreated females. The fertility index showed a tendency to decrease in males treated with 150 mg/kg/day. At necropsy, the pre-implantation loss rate in females mated with males treated with 150 mg/kg/day was higher than the control values. Upon epididymal sperm analysis using the CASA system, all parameters including the number of sperm and sperm motions were found to be affected in males treated with 500 mg/kg/day, and the number of sperm, percent motile, velocities and amplitude of lateral head displacement (ALH) were affected in males treated with 150 mg/kg/day. Upon sperm morphological examination, head and tail abnormalities were observed in males treated with 150 and 500 mg/kg/day. In the histopathological examination, atrophy of the seminiferous tubules and multinucleated giant cells in the testes were observed in males treated with 500 mg/kg/day.

Animals↗

PubMed2000

DNA ploidy analysis of urinary tract epithelial tumors by laser scanning cytometry.

OBJECTIVE: To evaluate a rapid and simple method for DNA content analysis of urinary tract epithelial tumors with laser scanning cytometry (LSC). STUDY DESIGN: The subjects were 25 patients (37 specimens) who underwent surgery for urinary tract epithelial tumors. Tissue specimens of such tumors were frozen immediately after tumor resection and stored at -80 degrees C until used. Touch preparations were made and fixed in ethanol at room temperature. The cell nucleus was stained with propidium iodide solution containing RNase, and DNA ploidy was analyzed by LSC. Nuclear debris and overlapping nuclei were gated out by special statistical filters. In LSC, a normal diploid reference peak was determined by observing lymphocytes morphologically on the computer display of the instrument and/or under the microscope. RESULTS: DNA ploidy could be evaluated in all tumor tissues. The time it took from preparing the tumor specimen to the last measurement was about 40 minutes at the shortest, and measurement of all the specimens was completed within one hour. The coefficient of variation was 2.8-7.8% (mean, 4.4%). All eight specimens (100%) at grade 1 (G1) were DNA diploid, but 20% and 85.7% of the G2 and G3 cells, respectively, were DNA aneuploid. In total, 15 of the 37 specimens were DNA aneuploid. All 17 pTa-pT1 specimens (100%) were DNA diploid, but 100% and 50% of the T2 and T3 tumors, respectively, were DNA aneuploid. CONCLUSION: One can now supplement a morphologic diagnosis with useful information using LSC of touch preparations of tumors obtained at surgery or of imprints of archived, frozen specimens. LSC provides excellent DNA histograms for surgical specimens and has great potential for clinical application in pathology.

Aged↗

PubMed2006

A systolic algorithm for Euclidean distance transform.

The Euclidean distance transform is one of the fundamental operations in image processing. It has been widely used in computer vision, pattern recognition, morphological filtering, and robotics. This paper proposes a systolic algorithm that computes the Euclidean distance map of an N x N binary image in 3N clocks on 2N(2) processing cells. The algorithm is designed so that the hardware resources are reduced; especially no mulitipliers are used and, thus, it facilitates VLSI implementation.

Algorithms↗

PubMed1984

[Computed tomography of chondrogenic tumors].

The computed tomography (CT) morphology of chondrogenic tumors and the utility of CT in their diagnostic work-up is presented on the basis of 19 cases. CT provided unique informations regarding definition of tumor extent and tumor relationship to adjacent structures particularly in the axial skeleton. CT has diminished the indications for angiography in chondrogenic tumors.

Acetabulum↗