Karsten Rodenacker - Academia.edu (original) (raw)
Papers by Karsten Rodenacker
For image evaluation in clinical routine, techniques like contrast-detail diagrams are commonly u... more For image evaluation in clinical routine, techniques like contrast-detail diagrams are commonly used. However, it is difficult to make an interpolation from these test results to real patient images. This problem can be solved by observer studies on the detection of certain pathology, which is often simulated by fixing external objects to healthy volunteers. This approach is relatively simple and
Chinese Journal of Cancer Research, 2000
Objective: To predict the outcome of dysplasia of esophageal epithelium by means of high resoluti... more Objective: To predict the outcome of dysplasia of esophageal epithelium by means of high resolution image analysis (HRIA). Methods: Asymptomatic adults were examined for balloon cytology of the esophagus in 1983 from Heshun Commune of Linxian County. 93 severe dysplasias and 122 mild dysplasias of the esophagus were selected. By means of an Axiomat-microscope equipped with TV-camera, 100 normal nuclei
Image Analysis & Stereology, 2000
Veterinary pathology, 1997
Canine pancreatic neuroendocrine tumors were studied using different image analysis techniques (n... more Canine pancreatic neuroendocrine tumors were studied using different image analysis techniques (nuclear image histometry, analysis of argyrophilic proteins of nucleolar organizer regions, determination of the mouse anti-Ki 67 antigen proliferation index, and DNA densitometry) to correlate their biological behavior with objective phenotypic markers. The methods were compared to determine the best method for distinguishing between metastatic and nonmetastatic tumors. Discrimination between the two types of tumor was possible using nuclear image histometry in combination with morphometric analysis of argyrophilic proteins of nucleolar organizer regions. In contrast, the mouse anti-Ki 67 antigen proliferation index, DNA measurement, and immunohistochemical parameters revealed no significant difference between the two types of tumors.
Analytical cellular pathology : the journal of the European Society for Analytical Cellular Pathology, 2003
Feature extraction is a crucial step in most cytometry studies. In this paper a systematic approa... more Feature extraction is a crucial step in most cytometry studies. In this paper a systematic approach to feature extraction is presented. The feature sets that have been developed and used for quantitative cytology at the Laboratory for Biomedical Image Analysis of the GSF as well as at the Center for Image Analysis in Uppsala over the last 25 years are described and illustrated. The feature sets described are divided into morphometric, densitometric, textural and structural features. The latter group is used to describe the eu- and hetero-chromatin in a way complementing the textural methods. The main goal of the paper is to bring attention to the need of a common and well defined description of features used in cyto- and histometrical studies. The application of the sets of features is shown in an overview of projects from different fields. Finally some rules of thumb for the design of studies in this field are proposed. Colour figures can be viewed on http://www.esacp.org/acp/2003/...
Analytical cellular pathology : the journal of the European Society for Analytical Cellular Pathology, 1998
Automatic cell segmentation has various application potentials in cytometry and histometry. In th... more Automatic cell segmentation has various application potentials in cytometry and histometry. In this paper, an automatic cluster (touching) cell segmentation approach using the dominant contour feature points has been presented. Dominant feature points are the locations of indentation on the contour of the cluster. First, dominant feature points on the contour of the cluster are detected by distance profile. Next, using shape features of the cells, these feature points are selected for segmentation. We compared the results of the proposed method with manual segmentation and observed that the method has an overall accuracy about to 82%.
Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology, 1998
To detect textural nuclear features correlated with nonprogression and progression in esophageal ... more To detect textural nuclear features correlated with nonprogression and progression in esophageal dysplasia. Asymptomatic adults from Heshun Commune, Linxian County, China were examined with a balloon sampler in 1983 fifty cases of moderate esophageal dysplasia and 68 cases of mild were selected for study. By means of an Axiomat microscope equipped with a TV camera, 100 visually normal intermediate squamous cell nuclei per specimen were randomly measured from routinely Papanicolaou-stained slides. Of 50 esophageal moderate dysplasia cases, 24 and 7 progressed to carcinoma within three and nine years, respectively. The other 19 cases remained stable or regressed to normal and were used as the control group. By means of chromatin features, correct specimen classification rates of 79.2% (19/24), 73.7% (14/19), 85.5% (6/7) and 84.2% (16/19) were achieved, respectively (P < .001). Of 68 cases classified as mild dysplasia, 16, 13 and 12 progressed to carcinoma within three, five and nin...
Analytical cellular pathology : the journal of the European Society for Analytical Cellular Pathology, 1997
Since 1983, a long-term clinical trial of esophageal carcinoma chemoprevention has been conducted... more Since 1983, a long-term clinical trial of esophageal carcinoma chemoprevention has been conducted in a high-risk area in China. From this study, 25 esophageal severe dysplasia patients without therapy were selected for analysis. After 5-year follow-ups, 14 cases progressed to esophageal carcinoma, while the other 11 cases remained stable. Three Papanicolaou's smears were used for each case, including one from the esophageal cytological examination at the beginning, two from the re-examinations three and five years later respectively. About 100 visually normal intermediate cells were randomly collected per slide by high resolution image analysis. More than 100 features (morphologic, densitometric, textural) were extracted. The classifications were made by means of stepwise linear discriminate analysis at the single cell level as on the specimen level using up to ten features. In all three comparisons of patients with progression and with regression at time of diagnosis, three yea...
Zentralblatt für Pathologie, 1994
Rat liver imprints were treated with five different fixation techniques. Chicken erythrocytes sto... more Rat liver imprints were treated with five different fixation techniques. Chicken erythrocytes stored over an extended period in the refrigerator were dropped on each slide before Feulgen staining. By means of an image analysis system chicken erythrocytes, rat leukocytes and hepatocytes were measured and the integrated optical density (IOD) was calculated for each nucleus. The coefficient of variation (CV) of IOD was about 15% for chicken erythrocytes. Leukocytes showed a CV of up to 10%. The CV was lower for hepatocytes than for leukocytes, and lowest for air-dried hepatocytes. The standard error of the mean (SEM) did not show remarkable differences between the fixation groups. For hepatocytes it was in general less than 1% of the respective mean value. The hepatocytes showed a linear staining except the wet formalin-fixed cells. This holds also for the wet formalin fixed leukocytes which showed only 85% of the IOD of 2c hepatocytes. The ratios of erythrocytes to 2c hepatocytes vari...
Cytometry, 1990
Sperm head cytometry provides a useful assay for the detection of radiation-induced damage in mou... more Sperm head cytometry provides a useful assay for the detection of radiation-induced damage in mouse germ cells. Exposure of the gonads to radiation is known to lead to an increase of diploid and higher polyploid sperm and of sperm with head shape abnormalities. In the pilot studies reported here quantitative analysis of the total DNA content, the morphology, and the chromatin distribution of mouse sperm was performed. The goal was to evaluate the discriminative power of features derived by high resolution image cytometry in distinguishing sperm of control and irradiated mice. Our results suggest that besides the induction of the above mentioned variations in DNA content and shape of sperm head, changes of the nonhomogeneous chromatin distribution within the sperm may also be used to quantify the radiation effect on sperm cells. Whereas the chromatin distribution features show larger variations for sperm 21 days after exposure (dpr), the shape parameters seem to be more important to ...
Conventional nerve conduits lack cellular and extracellular guidance structures critical for brid... more Conventional nerve conduits lack cellular and extracellular guidance structures critical for bridging larger defects. In this study, an exogenous matrix for axonal regeneration was provided by pretreated muscle tissue. In 24 rats, 14-mm sciatic nerve segments were resected and surgically reconstructed using one of the following methods: autograft (AG); bovine type I collagen conduit; (MDM) collagen tube filled with modified denatured autologous muscle tissue. For 8 weeks, functional regeneration was evaluated by footprint and video gait analysis. Evaluation was complemented by electrophysiology, as well as qualitative and quantitative structural assessment of nerves and target muscles. Group AG was superior both structurally and functionally, showing higher axon counts, a more normal gait pattern, and less severe muscle atrophy. Fiber quality (fiber size and myelin thickness) was highest in group MDM, possibly related to the myelin-producing effect of muscular laminin. However, axon count was lowest in this group, and ultrastructural analysis of the denatured muscle tissue showed areas of incomplete denaturation that had acted as a mechanical barrier for regenerating axons. In light of these results, the often advocated use of muscular exogenous matrix for peripheral nerve reconstruction is reviewed in the literature, and its clinical application is critically discussed. In conclusion, combined muscle tubes may have a positive influence on nerve fiber maturation. However, muscle pretreatment is not without risks, and denaturation processes need to be further refined.
Analytical Cellular Pathology, 1997
In molecular pathology numerical chromosome aberrations have been found to be decisive for the pr... more In molecular pathology numerical chromosome aberrations have been found to be decisive for the prognosis of malignancy in tumours. The existence of such aberrations can be detected by interphase fluorescence in situ hybridization (FISH). The gain or loss of certain base sequences in the desoxyribonucleic acid (DNA) can be estimated by counting the number of FISH signals per cell nucleus. The quantitative evaluation of such events is a necessary condition for a prospective use in diagnostic pathology. To avoid occlusions of signals, the cell nucleus has to be analyzed in three dimensions. Confocal laser scanning microscopy is the means to obtain series of optical thin sections from fluorescence stained or marked material to fulfill the conditions mentioned above. A graphical user interface (GUI) to a software package for display, inspection, count and (semi-)automatic analysis of 3-D images for pathologists is outlined including the underlying methods of 3-D image interaction and segmentation developed. The preparative methods are briefly described. Main emphasis is given to the methodical questions of computer-aided analysis of large 3-D image data sets for pathologists. Several automated analysis steps can be performed for segmentation and succeeding quantification. However tumour material is in contrast to isolated or cultured cells even for visual inspection, a difficult material. For the present a fully automated digital image analysis of 3-D data is not in sight. A semi-automatic segmentation method is thus presented here.
For image evaluation in clinical routine, techniques like contrast-detail diagrams are commonly u... more For image evaluation in clinical routine, techniques like contrast-detail diagrams are commonly used. However, it is difficult to make an interpolation from these test results to real patient images. This problem can be solved by observer studies on the detection of certain pathology, which is often simulated by fixing external objects to healthy volunteers. This approach is relatively simple and
Chinese Journal of Cancer Research, 2000
Objective: To predict the outcome of dysplasia of esophageal epithelium by means of high resoluti... more Objective: To predict the outcome of dysplasia of esophageal epithelium by means of high resolution image analysis (HRIA). Methods: Asymptomatic adults were examined for balloon cytology of the esophagus in 1983 from Heshun Commune of Linxian County. 93 severe dysplasias and 122 mild dysplasias of the esophagus were selected. By means of an Axiomat-microscope equipped with TV-camera, 100 normal nuclei
Image Analysis & Stereology, 2000
Veterinary pathology, 1997
Canine pancreatic neuroendocrine tumors were studied using different image analysis techniques (n... more Canine pancreatic neuroendocrine tumors were studied using different image analysis techniques (nuclear image histometry, analysis of argyrophilic proteins of nucleolar organizer regions, determination of the mouse anti-Ki 67 antigen proliferation index, and DNA densitometry) to correlate their biological behavior with objective phenotypic markers. The methods were compared to determine the best method for distinguishing between metastatic and nonmetastatic tumors. Discrimination between the two types of tumor was possible using nuclear image histometry in combination with morphometric analysis of argyrophilic proteins of nucleolar organizer regions. In contrast, the mouse anti-Ki 67 antigen proliferation index, DNA measurement, and immunohistochemical parameters revealed no significant difference between the two types of tumors.
Analytical cellular pathology : the journal of the European Society for Analytical Cellular Pathology, 2003
Feature extraction is a crucial step in most cytometry studies. In this paper a systematic approa... more Feature extraction is a crucial step in most cytometry studies. In this paper a systematic approach to feature extraction is presented. The feature sets that have been developed and used for quantitative cytology at the Laboratory for Biomedical Image Analysis of the GSF as well as at the Center for Image Analysis in Uppsala over the last 25 years are described and illustrated. The feature sets described are divided into morphometric, densitometric, textural and structural features. The latter group is used to describe the eu- and hetero-chromatin in a way complementing the textural methods. The main goal of the paper is to bring attention to the need of a common and well defined description of features used in cyto- and histometrical studies. The application of the sets of features is shown in an overview of projects from different fields. Finally some rules of thumb for the design of studies in this field are proposed. Colour figures can be viewed on http://www.esacp.org/acp/2003/...
Analytical cellular pathology : the journal of the European Society for Analytical Cellular Pathology, 1998
Automatic cell segmentation has various application potentials in cytometry and histometry. In th... more Automatic cell segmentation has various application potentials in cytometry and histometry. In this paper, an automatic cluster (touching) cell segmentation approach using the dominant contour feature points has been presented. Dominant feature points are the locations of indentation on the contour of the cluster. First, dominant feature points on the contour of the cluster are detected by distance profile. Next, using shape features of the cells, these feature points are selected for segmentation. We compared the results of the proposed method with manual segmentation and observed that the method has an overall accuracy about to 82%.
Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology, 1998
To detect textural nuclear features correlated with nonprogression and progression in esophageal ... more To detect textural nuclear features correlated with nonprogression and progression in esophageal dysplasia. Asymptomatic adults from Heshun Commune, Linxian County, China were examined with a balloon sampler in 1983 fifty cases of moderate esophageal dysplasia and 68 cases of mild were selected for study. By means of an Axiomat microscope equipped with a TV camera, 100 visually normal intermediate squamous cell nuclei per specimen were randomly measured from routinely Papanicolaou-stained slides. Of 50 esophageal moderate dysplasia cases, 24 and 7 progressed to carcinoma within three and nine years, respectively. The other 19 cases remained stable or regressed to normal and were used as the control group. By means of chromatin features, correct specimen classification rates of 79.2% (19/24), 73.7% (14/19), 85.5% (6/7) and 84.2% (16/19) were achieved, respectively (P < .001). Of 68 cases classified as mild dysplasia, 16, 13 and 12 progressed to carcinoma within three, five and nin...
Analytical cellular pathology : the journal of the European Society for Analytical Cellular Pathology, 1997
Since 1983, a long-term clinical trial of esophageal carcinoma chemoprevention has been conducted... more Since 1983, a long-term clinical trial of esophageal carcinoma chemoprevention has been conducted in a high-risk area in China. From this study, 25 esophageal severe dysplasia patients without therapy were selected for analysis. After 5-year follow-ups, 14 cases progressed to esophageal carcinoma, while the other 11 cases remained stable. Three Papanicolaou's smears were used for each case, including one from the esophageal cytological examination at the beginning, two from the re-examinations three and five years later respectively. About 100 visually normal intermediate cells were randomly collected per slide by high resolution image analysis. More than 100 features (morphologic, densitometric, textural) were extracted. The classifications were made by means of stepwise linear discriminate analysis at the single cell level as on the specimen level using up to ten features. In all three comparisons of patients with progression and with regression at time of diagnosis, three yea...
Zentralblatt für Pathologie, 1994
Rat liver imprints were treated with five different fixation techniques. Chicken erythrocytes sto... more Rat liver imprints were treated with five different fixation techniques. Chicken erythrocytes stored over an extended period in the refrigerator were dropped on each slide before Feulgen staining. By means of an image analysis system chicken erythrocytes, rat leukocytes and hepatocytes were measured and the integrated optical density (IOD) was calculated for each nucleus. The coefficient of variation (CV) of IOD was about 15% for chicken erythrocytes. Leukocytes showed a CV of up to 10%. The CV was lower for hepatocytes than for leukocytes, and lowest for air-dried hepatocytes. The standard error of the mean (SEM) did not show remarkable differences between the fixation groups. For hepatocytes it was in general less than 1% of the respective mean value. The hepatocytes showed a linear staining except the wet formalin-fixed cells. This holds also for the wet formalin fixed leukocytes which showed only 85% of the IOD of 2c hepatocytes. The ratios of erythrocytes to 2c hepatocytes vari...
Cytometry, 1990
Sperm head cytometry provides a useful assay for the detection of radiation-induced damage in mou... more Sperm head cytometry provides a useful assay for the detection of radiation-induced damage in mouse germ cells. Exposure of the gonads to radiation is known to lead to an increase of diploid and higher polyploid sperm and of sperm with head shape abnormalities. In the pilot studies reported here quantitative analysis of the total DNA content, the morphology, and the chromatin distribution of mouse sperm was performed. The goal was to evaluate the discriminative power of features derived by high resolution image cytometry in distinguishing sperm of control and irradiated mice. Our results suggest that besides the induction of the above mentioned variations in DNA content and shape of sperm head, changes of the nonhomogeneous chromatin distribution within the sperm may also be used to quantify the radiation effect on sperm cells. Whereas the chromatin distribution features show larger variations for sperm 21 days after exposure (dpr), the shape parameters seem to be more important to ...
Conventional nerve conduits lack cellular and extracellular guidance structures critical for brid... more Conventional nerve conduits lack cellular and extracellular guidance structures critical for bridging larger defects. In this study, an exogenous matrix for axonal regeneration was provided by pretreated muscle tissue. In 24 rats, 14-mm sciatic nerve segments were resected and surgically reconstructed using one of the following methods: autograft (AG); bovine type I collagen conduit; (MDM) collagen tube filled with modified denatured autologous muscle tissue. For 8 weeks, functional regeneration was evaluated by footprint and video gait analysis. Evaluation was complemented by electrophysiology, as well as qualitative and quantitative structural assessment of nerves and target muscles. Group AG was superior both structurally and functionally, showing higher axon counts, a more normal gait pattern, and less severe muscle atrophy. Fiber quality (fiber size and myelin thickness) was highest in group MDM, possibly related to the myelin-producing effect of muscular laminin. However, axon count was lowest in this group, and ultrastructural analysis of the denatured muscle tissue showed areas of incomplete denaturation that had acted as a mechanical barrier for regenerating axons. In light of these results, the often advocated use of muscular exogenous matrix for peripheral nerve reconstruction is reviewed in the literature, and its clinical application is critically discussed. In conclusion, combined muscle tubes may have a positive influence on nerve fiber maturation. However, muscle pretreatment is not without risks, and denaturation processes need to be further refined.
Analytical Cellular Pathology, 1997
In molecular pathology numerical chromosome aberrations have been found to be decisive for the pr... more In molecular pathology numerical chromosome aberrations have been found to be decisive for the prognosis of malignancy in tumours. The existence of such aberrations can be detected by interphase fluorescence in situ hybridization (FISH). The gain or loss of certain base sequences in the desoxyribonucleic acid (DNA) can be estimated by counting the number of FISH signals per cell nucleus. The quantitative evaluation of such events is a necessary condition for a prospective use in diagnostic pathology. To avoid occlusions of signals, the cell nucleus has to be analyzed in three dimensions. Confocal laser scanning microscopy is the means to obtain series of optical thin sections from fluorescence stained or marked material to fulfill the conditions mentioned above. A graphical user interface (GUI) to a software package for display, inspection, count and (semi-)automatic analysis of 3-D images for pathologists is outlined including the underlying methods of 3-D image interaction and segmentation developed. The preparative methods are briefly described. Main emphasis is given to the methodical questions of computer-aided analysis of large 3-D image data sets for pathologists. Several automated analysis steps can be performed for segmentation and succeeding quantification. However tumour material is in contrast to isolated or cultured cells even for visual inspection, a difficult material. For the present a fully automated digital image analysis of 3-D data is not in sight. A semi-automatic segmentation method is thus presented here.