COVID-19 pathophysiology and ultrasound imaging: A multiorgan review.

COVID-19 is a dynamic disease and may affect different tissues and organs as it progresses. Therefore, the impact generated by the disease in all its stages and organs requires a functional and versatile imaging technique able to detect particularities or artifacts dynamically. Ultrasonography fulfills all these requirements and exhibit several advantages relative to other imaging modalities, including portability, lower cost and biosafety. Throughout the COVID-19 pandemic, ultrasonography displayed a crucial role in the triage, monitoring, indicating organ damages and enabling individualized therapeutical decisions in COVID-19 patients. This review is dedicated to highlight the main pathological effects correlated with ultrasound changes caused by COVID-19 in the lungs, heart and liver.

Alteraciones en la distensibilidad arterial de pacientes dislipidémicos / Alterations in arterial compliance of dyslipidemic patients

Introducción: Se estudió la alteración en la distensibilidad de las paredes arteriales producidas por la dislipidemia dependiente de c-LDL a lo largo de las distintas décadas de la vida, utilizando el análisis de onda de pulso radial. Métodos: Se efectuó el registro de onda de pulso en la arteria radial mediante un transductor de movimiento apoyado sobre la zona de palpación, sobre un conjunto de 100 varones dislipidémicos sin otros factores de riesgo, de edades comprendidas entre la 3.a y la 6.a décadas de la vida. Se calculó en cada caso el índice de aumentación. También se identificó en los registros la onda reflejada y se definió un coeficiente de velocidad como el cociente entre la talla del individuo y el tiempo transcurrido entre el máximo de la onda sistólica y el instante de llegada de dicha onda. Los resultados se compararon con los de un conjunto de 161 voluntarios sanos. Resultados: Se halló que los dislipidémicos presentaron valores del índice de aumentación similares a los controles hasta la 4.a década, aumentando a partir de entonces, con diferencias significativas a partir de la 6.a década. No se hallaron diferencias significativas en el índice de velocidad en ninguna de las edades estudiadas. Conclusiones: Se concluye que las alteraciones producidas por la dislipidemia requieren décadas para manifestarse, y comienzan afectando al mecanismo de vasodilatación de las arterias distales con mayor proporción de músculo liso, sin alterar las arterias de conducción proximales con mayor contenido de elastina

Introduction: We studied the alteration on the distensibility of the arterial walls caused by dyslipidemia LDLc dependent, along the decades of life, by means of a study of the radial artery pulse wave. Methods: We made an analysis of the radial artery pulse wave records acquired by means a movement displacement sensor, placed on radial palpation area. We recruited 100 dyslipidemic men without other cardiovascular risk factors, between the 3rd and the 6th decade. We identified the reflected wave in the records and we computed the augmentation index in order to quantify its amplitude and position. This index is useful to assess the endothelial dysfunction. Besides, we defined a velocity coefficient as the ratio between the size of the individuals and the delay time between the peak of the systolic wave and the arrival of the reflected wave. Results were compared against those obtained in a group of 161 healthy volunteers. Results: We found that dyslipidemic patients presented augmentation index values similar to controls until the fourth decade, increasing thereafter with significant differences only in the 6th decade. No significant differences were found in the velocity index in any of the ages studied. Conclusions: We conclude that alterations produced by dyslipidemia take decades to manifest, and they begin affecting the mechanism of vasodilation of distal arteries with highest proportion of smooth muscle, without altering the proximal conduit arteries with more elastin content

[Alterations in arterial compliance of dyslipidemic patients]. / Alteraciones en la distensibilidad arterial de pacientes dislipidémicos.

INTRODUCTION: We studied the alteration on the distensibility of the arterial walls caused by dyslipidemia LDLc dependent, along the decades of life, by means of a study of the radial artery pulse wave. METHODS: We made an analysis of the radial artery pulse wave records acquired by means a movement displacement sensor, placed on radial palpation area. We recruited 100 dyslipidemic men without other cardiovascular risk factors, between the 3rd and the 6th decade. We identified the reflected wave in the records and we computed the augmentation index in order to quantify its amplitude and position. This index is useful to assess the endothelial dysfunction. Besides, we defined a velocity coefficient as the ratio between the size of the individuals and the delay time between the peak of the systolic wave and the arrival of the reflected wave. Results were compared against those obtained in a group of 161 healthy volunteers. RESULTS: We found that dyslipidemic patients presented augmentation index values similar to controls until the fourth decade, increasing thereafter with significant differences only in the 6th decade. No significant differences were found in the velocity index in any of the ages studied. CONCLUSIONS: We conclude that alterations produced by dyslipidemia take decades to manifest, and they begin affecting the mechanism of vasodilation of distal arteries with highest proportion of smooth muscle, without altering the proximal conduit arteries with more elastin content.

Probability mapping images in dynamic speckle classification.

We propose the use of a learning procedure to identify regions of similar dynamics in speckle image sequences that includes more than one descriptor. This procedure is based on the application of a naïve Bayes statistical classifier comprising the use of several descriptors. The class frontiers can be depicted so that the proportion of identified regions may be measured. To demonstrate the results, assembly of an RGB image, where each plane (R, G, and B) is associated with a particular region (class), was labeled according to its biospeckle dynamics. A high brightness in one color means a high probability of the pixel belonging to the corresponding class, and vice versa.

[Velocity estimation of aortic propagation based on radial pulse wave analysis]. / Estimación de la velocidad de propagación aórtica basada en el análisis de la onda de pulso radial.

We analyzed the possibility of using the radial pulse wave morphology, obtained by a movement transducer, to evaluate the aortic pulse wave velocity. The radial pulse wave signals were obtained by using a transducer, located on the pulse palpation area, in 167 healthy normotensive male volunteers, ages 20 to 70. The reflected wave was identified in every case. Also, a speed coefficient was defined as the ratio between the individual's height and the time between the maximum systolic wave and the arrival time of the reflected wave. We found that the specified coefficient in normotensive individuals increased linearly with age, in a similar way to the increase in aortic propagation velocity measured by other methods. The procedure was repeated on another set of 125 individuals with hypertension, without other risk factors, aged between the 3rd and 7th decade. This time we found similar values to normotensive individuals only on the 3th decade, and a pronounced increase on the velocity coefficient at advanced ages was observed. These findings support the feasibility of using this type of signals to indirectly evaluate the propagation velocity together with the increase index, a parameter commonly used in pulse wave analysis.

Estimación de la velocidad de propagación aórtica basada en el análisis de la onda de pulso radial / Velocity estimation of aortic propagation based on radial pulse wave analysis

Se exploró la posibilidad de utilizar la morfología del registro de onda de pulso radial obtenida mediante un transductor de movimiento para evaluar la velocidad de propagación aórtica. Se efectuó el registro de onda de pulso en arteria radial mediante un transductor apoyado sobre la zona de palpación del pulso, sobre un conjunto de 167 voluntarios varones sanos normotensos de edades comprendidas entre la 2ª y la 7ª década. Se identificó en los registros la onda reflejada y se definió un coeficiente de velocidad como el cociente entre la talla del individuo y el tiempo transcurrido entre el máximo de la onda sistólica y el instante de llegada de dicha onda. Se halló que en los normotensos el coeficiente mencionado aumentó en forma lineal con la edad, en una proporción similar al aumento de velocidad de propagación aórtica medido con otros métodos. Se repitió el procedimiento en otro conjunto de 125 varones hipertensos sin otros factores de riesgo, de edades entre la 3ª y la 7ª década, hallándose valores similares a los normotensos solamente en la 3ª década, a partir de la cual se registró un incremento significativo de dicho índice. Tales hallazgos sustentan la factibilidad de utilizar tal tipo de registros para evaluar indirectamente la velocidad de propagación junto con el índice de aumentación, un parámetro habitualmente utilizado en el análisis de onda de pulso.

We analyzed the possibility of using the radial pulse wave morphology, obtained by a movement transducer, to evaluate the aortic pulse wave velocity. The radial pulse wave signals were obtained by using a transducer, located on the pulse palpation area, in 167 healthy normotensive male volunteers, ages 20 to 70. The reflected wave was identified in every case. Also, a speed coefficient was defined as the ratio between the individual's height and the time between the maximum systolic wave and the arrival time of the reflected wave. We found that the specified coefficient in normotensive individuals increased linearly with age, in a similar way to the increase in aortic propagation velocity measured by other methods. The procedure was repeated on another set of 125 individuals with hypertension, without other risk factors, aged between the 3rd and 7th decade. This time we found similar values to normotensive individuals only on the 3th decade, and a pronounced increase on the velocity coefficient at advanced ages was observed. These findings support the feasibility of using this type of signals to indirectly evaluate the propagation velocity together with the increase index, a parameter commonly used in pulse wave analysis.

Biospeckle image stack process based on artificial neural networks.

This paper proposes the identification of regions of interest in biospeckle patterns using unsupervised neural networks of the type Self-Organizing Maps. Segmented images are obtained from the acquisition and processing of laser speckle sequences. The dynamic speckle is a phenomenon that occurs when a beam of coherent light illuminates a sample in which there is some type of activity, not visible, which results in a variable pattern over time. In this particular case the method is applied to the evaluation of bacterial chemotaxis. Image stacks provided by a set of experiments are processed to extract features of the intensity dynamics. A Self-Organizing Map is trained and its cells are colored according to a criterion of similarity. During the recall stage the features of patterns belonging to a new biospeckle sample impact on the map, generating a new image using the color of the map cells impacted by the sample patterns. It is considered that this method has shown better performance to identify regions of interest than those that use a single descriptor. To test the method a chemotaxis assay experiment was performed, where regions were differentiated according to the bacterial motility within the sample.

Índice para la evaluación de las reflexiones mediante análisis de la onda de pulso radial / Index of Pressure Wave Reflection Assessed from Radial Pulse Wave Analysis

En el presente trabajo se analiza la posibilidad de utilizar un parámetro obtenido del registro de la onda de pulso radial, el ancho de la onda sistólica, que es más sencillo de medir aún que el índice de aumentación radial y que complementaría a este último en la evaluación de la amplitud de la reflexión sistólica, directamente relacionada con el grado de disfunción endotelial y el fenómeno de aumentación aórtica. Se efectuó un estudio poblacional sobre 120 varones normotensos sanos con edades entre 17 y 65 años. Se obtuvo en ellos el registro de la onda de pulso radial en base al registro del movimiento de las paredes de la arteria mediante un sensor capacitivo aplicado sobre la zona de palpación del pulso. Cada registro se procesó y normalizó en amplitud y se calculó el índice de aumentación radial y el ancho de la onda sistólica al 50% de su altura máxima. Se halló que individuos con el mismo índice de aumentación poseían distintos valores de ancho de onda sistólica, lo cual evidencia distintos valores de amplitud de la onda reflejada. Ambos parámetros aumentaron con la edad y su correlación r resultó de 0,9. Se propone la utilización del ancho de la onda sistólica como un índice de envejecimiento alternativo, que permitiría evaluar el sistema arterial cuando la medición del índice de aumentación resultara dificultosa o la comparación entre individuos fuera ambigua.

Systolic wave width, a parameter obtained from the record of radial pulse wave, is easier to measure than the augmentation index. The aim of this study was to analyze the possibility of using systolic wave width as a complementary tool for the assessment of systolic wave reflection which is directly related to the degree of endothelial dysfunction and to aortic augmentation. We performed a population study on 120 healthy men between 17 and 65 years old with normal blood pressure. Records of the radial wave pulse were obtained, based on the movement of the arterial walls, by a capacitive sensor in contact with the surface of the wrist over the radial artery. Each record was processed and its amplitude was normalized; the augmentation index and systolic wave width at half its maximum height were calculated. We found that systolic wave width was different among subjects with the same augmentation index, showing different values of the amplitude of the reflected wave. Both parameters increased with age (r correlation value 0.9). The systolic wave width is an alternative index of ageing. It might assess the arterial system when it is difficult to measure augmentation index or when comparisons between individuals result ambiguous.

Monitoring dead space during recruitment and PEEP titration in an experimental model.

OBJECTIVE: To test the usefulness of dead space for determining open-lung PEEP, the lowest PEEP that prevents lung collapse after a lung recruitment maneuver. DESIGN: Prospective animal study. SETTING: Department of Clinical Physiology, University of Uppsala, Sweden. SUBJECTS: Eight lung-lavaged pigs. INTERVENTIONS: Animals were ventilated using constant flow mode with VT of 6ml/kg, respiratory rate of 30bpm, inspiratory-to-expiratory ratio of 1:2, and FiO(2) of 1. Baseline measurements were performed at 6cmH(2)O of PEEP. PEEP was increased in steps of 6cmH(2)O from 6 to 24cmH(2)O. Recruitment maneuver was achieved within 2min at pressure levels of 60/30cmH(2)O for Peak/PEEP. PEEP was decreased from 24 to 6cmH(2)O in steps of 2cmH(2)O and then to 0cmH(2)O. Each PEEP step was maintained for 10min. MEASUREMENTS AND RESULTS: Alveolar dead space (VD(alv)), the ratio of alveolar dead space to alveolar tidal volume (VD(alv)/VT(alv)), and the arterial to end-tidal PCO(2) difference (Pa-ET: CO(2)) showed a good correlation with PaO(2), normally aerated areas, and non-aerated CT areas in all animals (minimum-maximum r(2)=0.83-0.99; p<0.01). Lung collapse (non-aerated tissue>5%) started at 12[Symbol: see text]cmH(2)O PEEP; hence, open-lung PEEP was established at 14cmH(2)O. The receiver operating characteristics curve demonstrated a high specificity and sensitivity of VD(alv) (0.89 and 0.90), VD(alv)/VT(alv) (0.82 and 1.00), and Pa-ET: CO(2) (0.93 and 0.95) for detecting lung collapse. CONCLUSIONS: Monitoring of dead space was useful for detecting lung collapse and for establishing open-lung PEEP after a recruitment maneuver.

[Evaluation of hypertensive patients by radial arterial diameter variation recording]. / Evaluacion de hipertensos en base a registros de variacion de diametro arterial radial.

A blood less analysis technique of the diameter variation signal at radial artery was used to evaluate the arterial disease and the cardiovascular risk in hypertensive patients. A movement transducer was used to record the wrist pulse. A radial augmentation index was proposed to quantify the magnitude of the pressure wave reflections in the aortic region. The experiment was carried out with a group of 47 hypertensive men and compared with a similar study performed on 81 normotensive healthy men. The last ones presented smaller values of this index, but as age progresses, values of both groups come closer among them. This was confirmed by morphological comparison of both groups. Similar behavior was found in signals coming from healthy normotensive and hypertensive old men with similar age. Furthermore, some of the hypertensive youth presented similar morphological characteristics to normotensive of the same age. That indicates they still conserved the elastic behavior characteristic of its age group. These results, using available technology of smaller cost, were well-matched to those achieved by pressure signals at radial artery obtained by means of applanation tonometry.

Evaluación de hipertensos en base a registros de variación de diámetro arterial radial / Evaluation of hypertensive patients by radial arterial diameter variation recording

Se utilizó la técnica de análisis del registro incruento de las variaciones de diámetro de arteria radial para evaluar el deterioro arterial y el riesgo cardiovascular en pacientes hipertensos. El transductor utilizado consistió en un sensor de movimiento apoyado sobre la zona de palpación del pulso radial. Se efectuó la determinación del índice de aumentación radial, un parámetro que cuantifica la magnitud de las reflexiones de la onda de presión en la región aórtica, sobre un conjunto de 47 hipertensos, y se lo comparó con otro estudio similar efectuado sobre 81 normotensos sanos. Estos últimos presentaron menores valores de dicho índice, pero al avanzar la edad los valores de ambos grupos tendieron a coincidir. Esto fue confirmado al comparar morfológicamente los registros de ambos grupos, hallándose que los registros de ancianos normotensos sanos e hipertensos de edades similares resultaron visiblemente parecidos. Se halló también que determinados hipertensos jóvenes presentaron ciertas características morfológicas similares a las de normotensos de la misma edad, indicando que aún conservaban las características elásticas propias de su grupo etario. Los resultados fueron similares a los logrados sobre registros de presión arterial radial obtenidos mediante tonometría de aplanación, utilizándose una tecnología disponible en nuestro medio y de menor costo

A blood less analysis technique of the diameter variation signal at radial artery was used to evaluate the arterial disease and the cardiovascular risk in hypertensive patients. A movement transducer was used to record the wrist pulse. A radial augmentation index was proposed to quantify the magnitude of the pressure wave reflections in the aortic region. The experiment was carried out with a group of 47 hypertensive men and compared with a similar study performed on 81 normotensive healthy men. The last ones presented smaller values of this index, but as age progresses, values of both groups come closer among them. This was confirmed by morphological comparison of both groups. Similar behavior was found in signals coming from healthy normotensive and hypertensive old men with similar age. Furthermore, some of the hypertensive youth presented similar morphological characteristics to normotensive of the same age. That indicates they still conserved the elastic behavior characteristic of its age group. These results, using available technology of smaller cost, were well-matched to those achieved by pressure signals at radial artery obtained by means of applanation tonometry

Evaluación de hipertensos en base a registros de variación de diámetro arterial radial / Evaluation of hypertensive patients by radial arterial diameter variation recording

Se utilizó la técnica de análisis del registro incruento de las variaciones de diámetro de arteria radial para evaluar el deterioro arterial y el riesgo cardiovascular en pacientes hipertensos. El transductor utilizado consistió en un sensor de movimiento apoyado sobre la zona de palpación del pulso radial. Se efectuó la determinación del índice de aumentación radial, un parámetro que cuantifica la magnitud de las reflexiones de la onda de presión en la región aórtica, sobre un conjunto de 47 hipertensos, y se lo comparó con otro estudio similar efectuado sobre 81 normotensos sanos. Estos últimos presentaron menores valores de dicho índice, pero al avanzar la edad los valores de ambos grupos tendieron a coincidir. Esto fue confirmado al comparar morfológicamente los registros de ambos grupos, hallándose que los registros de ancianos normotensos sanos e hipertensos de edades similares resultaron visiblemente parecidos. Se halló también que determinados hipertensos jóvenes presentaron ciertas características morfológicas similares a las de normotensos de la misma edad, indicando que aún conservaban las características elásticas propias de su grupo etario. Los resultados fueron similares a los logrados sobre registros de presión arterial radial obtenidos mediante tonometría de aplanación, utilizándose una tecnología disponible en nuestro medio y de menor costo (AU)

A blood less analysis technique of the diameter variation signal at radial artery was used to evaluate the arterial disease and the cardiovascular risk in hypertensive patients. A movement transducer was used to record the wrist pulse. A radial augmentation index was proposed to quantify the magnitude of the pressure wave reflections in the aortic region. The experiment was carried out with a group of 47 hypertensive men and compared with a similar study performed on 81 normotensive healthy men. The last ones presented smaller values of this index, but as age progresses, values of both groups come closer among them. This was confirmed by morphological comparison of both groups. Similar behavior was found in signals coming from healthy normotensive and hypertensive old men with similar age. Furthermore, some of the hypertensive youth presented similar morphological characteristics to normotensive of the same age. That indicates they still conserved the elastic behavior characteristic of its age group. These results, using available technology of smaller cost, were well-matched to those achieved by pressure signals at radial artery obtained by means of applanation tonometry (AU)

Evaluación de hipertensos en base a registros de variación de diámetro arterial radial / Evaluation of hypertensive patients by radial arterial diameter variation recording

Se utilizó la técnica de análisis del registro incruento de las variaciones de diámetro de arteria radial para evaluar el deterioro arterial y el riesgo cardiovascular en pacientes hipertensos. El transductor utilizado consistió en un sensor de movimiento apoyado sobre la zona de palpación del pulso radial. Se efectuó la determinación del índice de aumentación radial, un parámetro que cuantifica la magnitud de las reflexiones de la onda de presión en la región aórtica, sobre un conjunto de 47 hipertensos, y se lo comparó con otro estudio similar efectuado sobre 81 normotensos sanos. Estos últimos presentaron menores valores de dicho índice, pero al avanzar la edad los valores de ambos grupos tendieron a coincidir. Esto fue confirmado al comparar morfológicamente los registros de ambos grupos, hallándose que los registros de ancianos normotensos sanos e hipertensos de edades similares resultaron visiblemente parecidos. Se halló también que determinados hipertensos jóvenes presentaron ciertas características morfológicas similares a las de normotensos de la misma edad, indicando que aún conservaban las características elásticas propias de su grupo etario. Los resultados fueron similares a los logrados sobre registros de presión arterial radial obtenidos mediante tonometría de aplanación, utilizándose una tecnología disponible en nuestro medio y de menor costo (AU)

A blood less analysis technique of the diameter variation signal at radial artery was used to evaluate the arterial disease and the cardiovascular risk in hypertensive patients. A movement transducer was used to record the wrist pulse. A radial augmentation index was proposed to quantify the magnitude of the pressure wave reflections in the aortic region. The experiment was carried out with a group of 47 hypertensive men and compared with a similar study performed on 81 normotensive healthy men. The last ones presented smaller values of this index, but as age progresses, values of both groups come closer among them. This was confirmed by morphological comparison of both groups. Similar behavior was found in signals coming from healthy normotensive and hypertensive old men with similar age. Furthermore, some of the hypertensive youth presented similar morphological characteristics to normotensive of the same age. That indicates they still conserved the elastic behavior characteristic of its age group. These results, using available technology of smaller cost, were well-matched to those achieved by pressure signals at radial artery obtained by means of applanation tonometry (AU)

Relación entre el envejecimiento y la morfología de los registros de variación de diámetro arterial: clasificación con redes neuronales artificiales / Relation between aging and the morphology of radial artery diameter variation registers: classification using artificial neural networks

El objetivo de este trabajo fue el estudio de la modificación de las ondas de variación de diámetro de la arteria radial (VDA) con el envejecimiento. Su registro se obtuvo con un sistema de adquisición que utiliza un transductor capacitivo apoyado sobre la piel a nivel de la arteria radial. Para evaluar la relación entre la pérdida de distensibilidad con el envejecimiento y las modificaciones de la VDA, el experimento se llevó a cabo en un grupo de 64 varones normotensos: 20 jóvenes, 24 adultos y 20 ancianos. Se extrajeron parámetros descriptivos morfológicos y se evaluó su poder para clasificar los registros de VDA según la edad con una red neuronal artificial de Kohonen. El proceso de análisis reveló la existencia de tres ondas constitutivas: dos ondas sistólicas, primera y segunda, y una diastólica. El envejecimiento produjo cambios importantes en la morfología de la señal, como el ensanchamiento de la primera onda sistólica, la disminución de amplitud de la onda diastólica y el ascenso de la segunda onda sistólica acercándose y solapándose con el vértice de la primera onda sistólica. La red neuronal artificial clasificó los 64 registros correctamente, localizándolos en el grupo de edades correspondiente. Considerando el carácter normotenso de los integrantes de la muestra se reveló la existencia de un modelo de envejecimiento arterial en pacientes sanos. Este sistema podría poner en evidencia precozmente la existencia de patologías arteriales que involucren incremento de la rigidez arterial con pérdida de distensibilidad (esclerosis, hipertensión).

Segmentación de biopsias de médula ósea mediante filtros morfológicos y rotulación de regiones homogéneas / Segmentation of bone marrow biopsies by morphological filters and labeling of flat zones

Este trabajo presenta un método semi-automático de detección de tejidos em biopsias de médula óssea utilizando técnicas de Processamento Digital de Imagens. Las técnicas utilizadas combinan filtrados morfológicos y detección de regiones homogéneas, con el fin de realizar un cálculo preciso de la celularidad medular. Os informes anátomo-patológicos de estos cortes histológicos entregan resultados porcentuales de la celularidas medular, indicando la prsencia de trabéculas, células adiposas y hamatopoyéticas. Dichos porcentajes permiten evalular la presencia y/o el grado de algún desorden metabólico, estableciendo comparaciones entre los valores normales y los patológicos. Generalmente, estas mediciones se realizam por simples inspección visual. El método propuesto permite calcular el porcentaje de trabéculas, células adiposas y hematopoyéticas. La identificación de trabéculas se basa en la aplicación de Filtros Morfológicos Alternativos Secuenciales por Reconstrucción y rotulación de regiones homogéneas. Todo el proceso es implementado en lenguaje MatLab® 6.5 con una interfase visual que permite operar el sistema sin ser experto en Procesamiento de Imágenes. El método fue probado con 26 imágines de biopsias de médula óssea que presentam distribuciones variadas de trabéculas. Se presenta un análisis comparativo entre los resultados obtenidos con el método propuesto y los calculados por dos patólogos especialistas donde la diferencia entre ambas estimaciones es menor al 12 por cento, mientras que las diferencias entre ellos llegan a ser has de 20 por cento. Tanto los resultados visuales como los numéricos indican que el método es altamente eficiente para esta aplicación.

Semiautomated image segmentation of bone marrow biopsies by texture features and mathematical morphology.

OBJECTIVE: To present the preliminary results of a method for semiautomated detection of fat and hematopoietic cells as well as trabecular surfaces in bone marrow biopsies in order to calculate the percentage of each type of tissue or cell area in relation to the whole area. STUDY DESIGN: The results were derived from selected clinical cases. Twenty-six biopsies were used, presenting varied distributions of cellularity and trabecular topography. The approach is based on digital image processing techniques and pattern recognition methods using textural features obtained from biopsy images. The results were improved with mathematical morphology filters. RESULTS: A low computational cost algorithm is obtained that produces highly satisfactory results. The method is faster and more reproducible than conventional ones, such as region growing, edge detection, splitting and merging. CONCLUSION: The results with this computer-assisted technique were compared to those obtained by visual inspection by 2 expert pathologists, and differences of < 9% were observed.