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Results for “computational morphology”

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PubMed2003

Non-invasive assessment of plaque morphology and remodeling in mildly stenotic coronary segments: comparison of 16-slice computed tomography and intravascular ultrasound.

BACKGROUND: Non-invasive identification and characterization of mildly stenotic atherosclerotic lesions is an increasingly important focus of coronary imaging. DESIGN: We examined the accuracy of multi (16)-slice computed tomography (MSCT) for imaging of these lesions in comparison with intravascular ultrasound (IVUS). MATERIALS: Mildly stenotic segments of the left coronary artery were identified by coronary angiography and analyzed using IVUS and contrast-enhanced MSCT. Independent reviewers evaluated the accuracy of MSCT for presence, composition and distribution of atherosclerotic plaque and remodeling response in comparison to IVUS using receiver operating characteristic (ROC) data analysis. RESULTS: Of 46 segments in 14 patients, diagnostic characterization by MSCT was possible in 37 (80.4%) segments. In these segments the accuracy of MSCT for identifying plaque presence, calcification, distribution and positive remodeling was consistently greater than 0.90 (reader 1) and 0.87 (reader 2). CONCLUSION: State-of-the-art MSCT can accurately identify mildly stenotic coronary atherosclerosis and provide an assessment of morphology and remodeling response.

Adult↗

PubMed2005

Angulation, length, and morphology of the styloid process of the temporal bone analyzed by multidetector computed tomography.

PURPOSE: To investigate the angulation, length, and structural variations of the styloid process (SP) by multidetector computed tomography (MDCT). MATERIAL AND METHODS: MDCT scans were performed in 283 cases (127 M and 156 F, age range 18-77 years). The length of the SP and its angulation on the transverse and sagittal planes were measured. Structural variations of the SP were observed by means of three-dimensional (3D) and multiplanar reconstruction (MPR) images. RESULTS: The length of the bony SP on both sides varied from 0 to 62 mm (mean 26.8 +/- 10.0 mm). Angulation ranged between 55 degrees and 90.5 degrees (7 2.7 +/- 6.6) in the transversal plane and between 76 degrees and 110 degrees (93.5 +/- 6.9) in the sagittal plane. Morphologically, the SP showed a considerable amount of variation. A solitary SP was present in 168 individuals (59.4%). In 9 individuals (3.1%), the SP was duplicated (4 unilateral and 5 bilateral). Sixty-one persons (21.6%) showed an incomplete ossified SP (42 unilateral and 19 bilateral), whereas in 7 individuals (2.5%) a bony SP was absent entirely (7 unilateral). In 38 individuals (13.4%), the stylohyoid ligament was ossified (16 entirely, 22 partial). In all individuals, 3D and MPR images showed the SP in its entire length. CONCLUSION: MDCT with 3D CT and MPR of SP may show further detailed information related to SP. Not only the length of the SP, but also its 3D orientation, should be in focus in anatomical and clinical studies.

Adolescent↗

PubMed2000

Visualization and quantification of coronary calcifications with electron beam and spiral computed tomography.

This contribution reviews the pathology and morphology of coronary calcifications. It summarizes the indications for investigation of the coronary arteries. The standard protocols for scan acquisition using electron beam and conventional computed tomography are described as well as various methods for evaluation such as the traditional Agatston scoring method and the newer three-dimensional scoring algorithms. Guidelines for interpreting scores are also reviewed. Major limitations of the reproducibility of the calcium score measurement are summarized. Future aspects of multirow-detector spiral computed tomography with retrospective electrocardiographic triggering for quantifying coronary calcium are discussed.

Calcinosis↗

PubMed1998

[Integration of functional and morphologic MRI data for preoperative 3D visualization of tumors. Example: cervical carcinoma].

PURPOSE: The goal of this exemplary study was to integrate morphological and functional MRI to establish computer-based, pre-operative therapy planning for tumors, instancing cervical carcinoma. METHODS: For morphological representation T1-weighted, filtered 3D sequences were investigated within a hierarchical segmentation approach. Using a method for image registration, segmented structures were combined and overlaid with functional information of contrast medium-enhanced, dynamic MRI. After assigning colour attributes to the segmented structures, they were presented using a method for direct volume visualisation. RESULTS: Segmentation of organs and vessels as well as tissue differentiation yielded a morphological visualisation of anatomical structures that were overlaid with pharmacokinetic parameters derived from dynamic MRI, subsequently. Thereby, three-dimensional, arbitrary views on the functional data were displayed. CONCLUSIONS: Image analysis and visualisation of the acquired MR data establishes both a morphologic and functional evaluation of suspect lesions and adjacent organs. By integrating morphologic and functional MRI additional information can be gathered that possibly impinge on preoperative planning.

Data Interpretation, Statistical↗

PubMed1990

System for flow sorting chromosomes on the basis of pulse shape.

Sorting on the basis of the complex features resolved by chromosome slit-scan analysis requires rapid and flexible pulse shape acquisition and processing for determining sort decisions before droplet breakoff. Fluorescence scans of chromosome morphology contain centromeric index and banding information suitable for chromosome classification, but these scans are often characterized by variability in length and height and require sophisticated data processing procedures for identification. Setting sort criteria on such complex morphological data requires digitization and subsequent computation by an algorithm tolerant of variations in overall pulse shape. We demonstrate here the capability to sort individual chromosomes based on their morphological features measured by slit-scan flow cytometry. To do this we have constructed a sort controller capable of acquiring an 128 byte chromosome waveform and executing a series of numerical computations resulting in an area-based centromeric index sort decision in less than 2 ms. The system is configured in a NOVIX microprocessor, programmed in FORTH, and interfaced to a slit-scan flow cytometer data acquisition system. An advantage of this configuration is direct control over the machine state during program execution for minimal processing time. Examples of flow sorted chromosomes are shown with their corresponding fluorescence pulse shapes.

Animals↗

PubMed1993

Rib cage deformities in scoliosis: spine morphology, rib cage stiffness, and tomography imaging.

A computer-implemented biomechanical model of a thoracolumbar spine and deformable rib cage was used to investigate the influence of spine morphology and rib cage stiffness properties on the rib cage deformities that arise from scoliosis and to study the relationship of actual rib distortions with those seen on computed tomography (CT) scans. For the purposes of this study, it was assumed that rib cage deformities result from forces imposed on the ribs by the deforming spine. When a structurally normal rib cage was allowed to follow freely the imposition of scoliotic curves on the spine, different configurations of scoliosis led to substantial differences in the resulting rib cage deformities. Rib cage lateral offset correlated well with the Cobb angle of the scoliosis but not with the apical vertebral axial rotation, whereas rib cage axial rotation correlated well with apical vertebral axial rotation but not with the Cobb angle. These model-obtained findings mirror clinical findings that correction of the Cobb angle leads to correction of the lateral offset of the rib cage but does not correlate well with correction of the rib cage axial rotation. The stiffnesses of the ligamentous tissue connecting the sternum to the pelvis, of the costovertebral joints, and of the ribs themselves also influenced the rib deformities substantially. The influence of the sternopelvic ligamentous ties has not been recognized previously. The total rib cage volume remained essentially constant regardless of the severity of the resulting deformity, but the distribution of this volume between convex and concave sides varied somewhat.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomechanical Phenomena↗

PubMed2004

Morphologic changes in the cervical neural foramen due to flexion and extension: in vivo imaging study.

STUDY DESIGN: Dimensional measurement of cervical neural foramen at various positions, using reformatted computed tomography. OBJECTIVES: To examine the morphologic changes in the neural foramen during flexion and extension of the cervical spine in vivo. SUMMARY OF BACKGROUND DATA: Previous cadaveric studies have shown the effect of cervical spinal motion on dimensions of the neural foramen. However, little information is available about dynamic morphologic changes in the cervical neural foramen in vivo. METHODS: Cervical CT images of seven healthy volunteers were taken at the neutral position, maximum extension, and maximum flexion, and were reconstructed in the oblique plane perpendicular to the long axis of each neural foramen from the C3-C4 to C6-C7 level. Measured parameters included foraminal height, width, cross-sectional area, and segmental sagittal rotation at each spinal level. Differences in neural foraminal dimensions among these positions were analyzed. Correlations of segmental sagittal rotation with differences in dimensions between flexion and extension were analyzed. RESULTS: Flexion significantly increased the foraminal height (by 1.0 mm; 11%), foraminal width (by 1.0 mm; 16%), and foraminal area (by 12 mm2; 28%) (P < 0.01). Extension significantly decreased the foraminal height (by 0.9 mm; 10%), foraminal width (by 1.4 mm; 22%), and foraminal area (by 8.0 mm2; 17%) (P < 0.01). Segmental sagittal rotation significantly positively correlated with % change in foraminal height (r = 0.434, P < 0.01) and area (r = 0.504, P < 0.01). CONCLUSIONS: The present results are consistent with those of previous in vitro studies and may explain the clinical observation that cervical extension aggravates symptoms in patients with cervical radiculopathy and that flexion often relieves them.

Adult↗

PubMed1997

Morphologic evaluation and surgical simulation of ossification of the posterior longitudinal ligament using helical computed tomography with three-dimensional and multiplanar reconstruction.

STUDY DESIGN: Using helical computed tomography with three-dimensional and multiplanar reconstruction, ossification of the posterior longitudinal ligament in the cervical and thoracic region was observed. Preoperative simulation also was performed, and the availability of these methods was evaluated. OBJECTIVE: To use preoperative evaluation and simulation with helical computed tomography to enhance the accuracy of excision of ossification of the posterior longitudinal ligament lesion. SUMMARY OF BACKGROUND DATA: Ossification of the posterior longitudinal ligament lesion is sometimes so complicated that preoperative morphologic evaluation and excision of the lesion are difficult when using only conventional imaging techniques. METHODS: Seven cases of cervical and two cases of thoracic ossification of the posterior longitudinal ligament were scanned using helical computed tomography at 2-mm or 5-mm slice thickness. Three-dimensional and multiplanar reconstruction were performed at 0.7-mm or 2-mm intervals in the bone window. Surgical simulation of the anterior approach for cervical lesion and posterior approaches for thoracic lesion was performed. RESULTS: Preoperative direct observation of the ossification of the posterior longitudinal ligament lesion was possible, and the complicated structures could be understood more easily than with other conventional methods. When surgical simulation was performed in the workstation, the ossification of the posterior longitudinal ligament lesion was removed sufficiently on arbitrarily reconstructed view in the spinal canal. When the viewpoint then was changed to the approaching side, the location and dimension of the removed area were determined. In all cases, surgical approach and excision of the ossification of the posterior longitudinal ligament lesion were performed more easily and more precisely than in the surgery with no three-dimensional images. CONCLUSION: Helical computed tomography with three-dimensional, multiplanar reconstruction would be a valuable tool for evaluation and surgical simulation of ossification of the posterior longitudinal ligament lesion by enhancing the accuracy of the surgical procedure.

Adult↗

PubMed1995

The functional hepatic volume assessed by 99mTc-GSA hepatic scintigraphy.

The accuracy of measurement of the functional hepatic volume by single photon emission computed tomography (SPECT) with 99mTc-galactosyl serum albumin (99mTc-GAS) was evaluated. 99mTc-GSA planar scintigraphic images were obtained dynamically and the hepatic SPECT imaging was then performed in 25 patients with hepatobiliary tumors. The patients were divided into 4 groups with normal hepatic function, and mild, moderate and severe hepatic dysfunction. The functional hepatic volume determined by SPECT was compared with the morphological hepatic volume determined by compute tomography. The ratio of the hepatic volumes obtained by the two methods was calculated. The mean hepatic volume ratio was 96.6 +/- 2.3% in the normal hepatic function group and 95.9 +/- 2.2% in the mild dysfunction group (n.s.). In both the moderate and severe hepatic dysfunction groups, the hepatic volume ratio was smaller than that in the normal group (87.9 +/- 5.2%, p < 0.0001, and 71.9 +/- 7.6%, p < 0.0001, respectively). There was a linear correlation between the hepatic volume ration and various indices of reserve hepatic function, such as LHL15 (r = 0.83, p < 0.0001), HH15(r = 0.74, p < 0.0001), and ICG15 (r = 0.75, p < 0.0005). These results indicate that the hepatic volume ratio is proportional to the severity of hepatic dysfunction, and suggest that the functional hepatic volume measured with 99mTc-GSA faithfully reflects the functioning hepatocyte mass. 99mTc-GSA scintigraphy and hepatic SPECT therefore provide information regarding global and regional reserve hepatic function.

Adult↗

PubMed2003

Early detection of radiation-induced structural changes in rat trabecular bone.

OBJECTIVE: Early detection of bone changes following radiotherapy is very important. The aim of this study is to establish a radiographic image analysis method for early detection of radiation-induced trabecular bone changes. METHODS: Thirty-five Wistar rats were used for the experimental model of trabecular bone changes, which were induced by X-ray irradiation with 30 Gy to develop simulated osteomyelitis. Standardized 2.2 x direct magnification radiography was performed immediately prior to X-ray irradiation and once a week for 4 weeks following irradiation. The latent X-ray images were scanned using a computed radiography (CR) system. Mathematical morphological processing was then applied to the CR image data, which allowed the bone trabecular pattern features to be extracted as skeletal binary images. The sensitivity and specificity for detecting early trabecular bone changes in CR images and in skeletal binary images were evaluated. Quantitative analyses with quantum level value (QL value), skeletal pixel percentage (SKP) and star volume analysis (skeletal volume (Vsk), skeletal space volume (Vsp)) were performed. Histopathological examination was also conducted for confirmation of physical changes in the bone. RESULTS: Visual observation of the skeletal binary images provided a higher sensitivity than the CR images. In the quantitative analysis, SKP, Vsk and Vsp values provided higher sensitivity than QL values. CONCLUSION: The results of the present study suggest that a combined radiographic image analysis method using CR, mathematical morphological processing, SKP, Vsk and Vsp can be useful for the early detection of radiation-induced trabecular bone changes.

Analysis of Variance↗

PubMed2006

[Differential diagnosis of benign and malignant solitary pulmonary nodule with computer-aided detection].

OBJECTIVE: To investigate the morphological features of benign and malignant solitary pulmonary nodules (SPNs) and explore the radiological evidences for the differentiation of SPNs. METHODS: With SPN Dicom View software, we analyzed and compared images obtained from 23 patients with malignant SPNs and 22 patients with benign SPNs who received CT scanning with or without contrast medium injection. RESULTS: The enhancement in malignant SPNs group was significantly higher than in the benign SPNs group (P < 0.0001). The irregular enhancement in malignant SPNs group was significantly higher than in the benign SPNs group (P = 0. 0084). The mean range of enhancement was (45.04 +/- 26.76) HU in malignant SPNs group, which was significantly higher than that in the benign SPNs group [(15.70 +/- 17.84) HU, P = 0.033]. The mean peak enhancement value was (136.09 +/- 41.72) HU in malignant SPNs group, which was significantly higher than in benign SPNs group [ (60.60 +/- 60.27) HU, P = 0.007]. The mean enhancement area was (21.69 +/- 21.01)% in malignant SPNs group and (8.61 +/- 10.83)% in benign SPNs group (P = 0.203). CONCLUSION: The enhancement range and peak enhancement value as well as the morphologically irregular enhancement of SPNs may provide useful information in the clinical radiological diagnosis of SPNs.

Adult↗

PubMed1986

Neuritogenic and metabolic effects of individual gangliosides and their interaction with nerve growth factor in cultures of neuroblastoma and pheochromocytoma.

The 4 major ganglioside species, GM1, GD1a, GD1b and GT1b (200 micrograms/ml), were tested individually for the ability to stimulate neuronal trophic responses. The growth parameters measured were: morphologic changes, quantitated by computer-assisted morphometry of neurite length and number per soma, and metabolic changes, indicated by alterations in ornithine decarboxylase activity (ODC). In addition, the interaction of each ganglioside with nerve growth factor (NGF) was investigated with an NGF-responsive pheochromocytoma PC12 cell line and NGF-insensitive neuroblastoma Neuro-2a cultures. PC12 cells responded to gangliosides only in the presence of NGF (20 micrograms/ml): GM1 produced the greatest morphologic response, but did not alter metabolic levels; GT1b increased both parameters. The presence (5 micrograms/ml) or absence of NGF did not have an effect on the ganglioside-mediated morphologic responses of Neuro-2a cells to each species: GD1b elicited the greatest increase in neurite length, while GD1a and GT1b stimulated both length and number. In contrast, while GT1b alone was able to elevate ODC activity independently of NGF, the simultaneous exposure of Neuro-2a cultures to NGF and GM1 or GD1a resulted in a stimulation of cellular metabolism. These results indicate that each ganglioside species has a specific target action in the stimulation of different trophic responses and that performance in one category is not a predictor of the result in another. In addition, it is possible to confer a sensitivity to NGF by simultaneous treatment with specific gangliosides. This indicates that membrane gangliosides may modulate the actions of neurotrophic factors.

Animals↗

PubMed2004

Automated sperm morphometry and morphology analysis of canine semen by the Hamilton-Thorne analyser.

Computer-assisted sperm morphometry has the potential to eliminate several drawbacks inherent to the current methods of sperm morphology evaluation, and allows for the identification of subtle sperm characteristics which cannot be detected by visual evaluation. In the present study, the Metrix Oval Head Morphology software implemented in the Hamilton-Thorne CEROS (version 12.1; HTR 12.1 Metrix) computer-aided semen analyser was evaluated for canine sperm morphometry and morphology analysis. Comparison of sperm morphometric measurements of 200 spermatozoa from pooled semen samples (n = 4) at 40x and 60x demonstrated a more accurate identification of the sperm head boundaries at a magnification level 60x. Dilution of pooled semen samples (n = 4) to a sperm concentration of 50 x 10(6) ml(-1) allowed for a correct evaluation of the sperm cell dimensions whereas 100 x 10(6) and 200 x 10(6) ml(-1) resulted in a higher percentage of rejected spermatozoa due to overlapping. No differences in morphometric dimensions were found when 100 or 200 spermatozoa were evaluated for each of 15 dogs. The mean morphometric parameters of canine spermatozoa, based on the fresh ejaculates of 23 dogs, were: major 6.65 +/- 0.20 microm; minor 3.88 +/- 0.14 microm; area 20.66 +/- 1.04 microm2; elongation 58.64 +/- 2.58 %; perimeter 17.57 +/- 0.43 microm and tail length 48.93 +/- 10.16 microm. Large variations in morphometric dimensions were detected among individual dogs. After cryopreservation, significantly lower morphometric dimensions were obtained for all the evaluated sperm samples (n = 12). Finally, a correlation of 0.82 (P < 0.05) was established for the percentage of normal spermatozoa assessed by subjective evaluation and by the HTR 12.1 Metrix (n = 39 semen samples). In conclusion, dilution of the semen samples to approximately 50 x 10(6) spermatozoa/ml and an objective lens magnification of 60x, analysing at least 100 spermatozoa, are the technical settings proposed to obtain reliable and objective sperm morphometric measurements by the HTR 12.1 Metrix in canine.

Animals↗

PubMed1987

[Diagnostic potentials of computed tomography in tumors of the thymus].

115 patients with different morphological thymus lesions, including 67 with thymoma have been examined on a computer tomograph "Somatom DR-2" ("Siemens", FRG). Characteristic features of hyperplasia and thymus cysts, as well as benign and malignant thymus tumours have been revealed by computer tomography (CT). Diagnostic value of CT in conditions of pneumomediastinum and CT employing an "amplification" technique in dynamic CT-scanning (angio-CT) in combination with puncture tumour biopsy under CT control are discussed. CT was found to have certain advantages over other diagnostic techniques: simplicity, safety, the value of the information obtained, possible shortening of the diagnostic period.

Biopsy, Needle↗

PubMed2005

Phenotypic analysis of adults and eggs of Fasciola hepatica by computer image analysis system.

Knowledge of the morphological phenotypes of the liver fluke Fasciola hepatica (Trematoda: Digenea) is analysed. The influence of parasite age on its dimensions, the adult fluke growth model, variation in a biometric variable versus time, and variation in a biometric variable versus another biometric variable (allometric model) are revised. The most useful allometric model appears to be (y2 m-y2)/y2=c [(y1 m-y1)/y1](b), where y1=body area or body length, y2=one of the measurements analysed, y1 m, y2 m=maximum values towards which y1 and y2, respectively, tend, and c, b=constants. A method based on material standardization, the measurement proposal and allometric analysis is detailed. A computer image analysis system (CIAS), which includes a colour video-camera connected to a stereomicroscope (for adult studies) and a microscope (for egg studies), facilitates the processing of digital imaging. Examples of its application for the analysis of the influence of different factors on the liver fluke phenotype are shown using material from the Northern Bolivian Altiplano, where human and domestic animal fascioliasis is caused by F. hepatica only. Comparisons between the development of livestock fluke populations from highlands and lowlands are discussed and the relationships between host species and liver fluke morphometric patterns is analysed.

Altitude↗

PubMed1990

Comparison of color flow and 3D image by computer graphics for the evaluation of carotid disease.

Morphologic characteristics and hemodynamics in the carotid artery were investigated in patients with stroke by use of Doppler color-flow analysis and three-dimensional (3D) analysis by computer graphics. The 3D imaging of the carotid bifurcation was reconstructed from a series of transverse B-mode images. Comparison of color-flow and 3D images demonstrated that wall configuration in vivo, dilation, and curvature play an important role in reversal of flow and stagnation at the carotid bifurcation. Furthermore, 3D analysis is very useful in mapping the distribution of the atheromatous plaques. The analyses suggest that it is important to investigate the wall configuration of the bifurcation in vivo on flow patterns, especially flow separation and stagnation, in relation to the development of atheromatous plaques.

Arteriosclerosis↗

PubMed1992

Ultrafast computed tomography of the heart.

Recent cardiovascular morphologic studies focus on direct innovative ultrafast CT applications in detecting coronary calcifications and assessing pericardial diseases. In functional studies, quantitation of regional and global indicators of myocardial function and structure, such as wall thickness or thickening, volume, and mass, can be performed using ultrafast CT and MR imaging with similar approaches. Recent ultrafast CT developments illustrate the fact that cardiac tomographic imaging is evolving rapidly. The production of three-dimensional images from tomography, which is still uncommon, has enhanced resolution and wall motion analysis. Applications will have a major impact on the knowledge of cardiac physiology and the understanding of cardiovascular diseases, if not in daily patient care. Further developments in computer-automated analysis from cardiac ultrafast CT or MR images must be carried out to gain clinical acceptance and to facilitate the routine and consistent measurements of the parameters of cardiac function.

Calcinosis↗

PubMed2005

Relationship between masticatory function and internal structure of the mandible based on computed tomography findings.

INTRODUCTION: The purposes of this study were to investigate bone mineral density as a part of bone construction in human skulls and to examine the relationship between dentofacial morphology and masticatory function by using computed tomography (CT) findings. Changes in bone mineral density in the mandible because of loss of masticatory function were tested in rats by experimentally producing an environment that inhibited mastication by the molars. METHODS: Data for the human study were obtained from 27 modern male Japanese skulls (mean age, 28 years) from the University of Tokyo. Cortical bone thickness (CBT) and CT value (CV) were measured by each CT scan of the first and molars. For the animal study, a metal cap was inserted between the maxillary and mandibular incisors to prevent the molars from biting in 6-week-old male Wistar rats. The rats were killed after 2, 4, or 6 weeks, and bone mineral density was measured in cancellous and cortical bone equivalent to the first molar region by using peripheral quantitative computed tomography. RESULTS: In the human skull study, significant negative correlations were observed between CV in the regions of the buccal side of the second molar and the angle between the Frankfort horizontal and mandibular planes. Significant negative correlations were also observed between the gonial angle and CV in the buccal and basal sides. In the animal study, cancellous bone mineral density began to decline 4 weeks after the start of the experiment in the masticatory hypofunction group compared with the control group. By week 6, cancellous bone density had declined by 11.6% on the buccal side, 16.7% on the lingual side, 12.3% at the bifurcation of the root, and 38.1% at the root apex. Cortical bone density declined by 8% to 12% on the lingual side. CONCLUSIONS: The results support our hypothesis that a functional adaptive response by the mandible to mechanical stress resulting from mastication occurs not only in the muscle insertion area, but also in mandibular alveolar bone in the molar region.

Adaptation, Physiological↗