Assessing competency for remote telecytology rapid on-site evaluation using pre-recorded dynamic video streaming.

INTRODUCTION: Telecytology using real-time microscopy has gained popularity for rapid on-site evaluations (ROSE). Although proficiency testing is routinely used in cytopathology, no established means of competency assessment is currently available for telecytology. Our aim was to determine the feasibility of a dynamic (real-time) platform to assess telecytology competency. METHODS: Remote Medical Technology dynamic (real-time) video streaming platform for ROSE is used at our institution, and short video clips of telecytology cases were recorded using Camtasia Studio 8 software during different ROSE sessions. Selected MP4 videos (range 13-88 seconds, mean 33 seconds), along with clinical histories, were used to build a multiple-choice question test with one training case and 20 test cases, utilising Tutor (Philips) software to host the web-based test. The test was voluntary for cytopathologists and cytotechnologists. Answers and feedback from test takers were analysed. RESULTS: Thirteen participants-four cytopathologists and nine cytotechnologists-previously trained to use telecytology, volunteered to take the test. Individual scores ranged from 10 (50%) to 19 (95%) with a median of 16 (80%). Most feedback received involved technical difficulties. CONCLUSIONS: We present, to the best of our knowledge, the first tool to assess telecytology competency for ROSE using pre-recorded dynamic streaming videos. Despite technical challenges related to incorporating videos into a web-based test, the test was feasible and provided users with valuable feedback about their ROSE performance. Future effort will be devoted to establishing a more user-friendly test platform and establishing a benchmark for passing scores.

The Reproducibility of the Point of Care Microcirculation (POEM) Score When Used to Assess Critically Ill Patients: A Multicenter Prospective Observational Study.

BACKGROUND: The current standard of analyzing microcirculatory video microscopy is time-consuming and occurs away from the patient, limiting its clinical utility. Point-of-care assessment with incident dark field (IDF) microscopy, however, may offer greater clinical applicability. We aimed to determine the reproducibility of the Point of Care Microcirculation (POEM) tool when used at the bedside in critically ill patients. METHODS: A multinational, multicenter, prospective observational study of adult intubated patients was undertaken during a 9-month period in Germany, the United Kingdom, and the United States. A user recorded a batch of four standardized video clips from each patient, calculated a POEM score and recorded the time for image acquisition. A second user blinded to the first repeated this process. Patients with video clips of poor quality were excluded. At a later date, the two users again blinded themselves to reassess both their own clips and those of the other user. Basic demographic information was recorded. Intrauser reliability (an individual user rescoring the same batch of videos after blinding), interuser reliability (a second user rescoring the other user's video batch after blinding), and test-retest reliability (two users individually capturing videos and recording POEM scores) were assessed using a linearly weighted kappa statistic for ordinal data. RESULTS: Sixty-five patients were included in the final analysis. Observer agreement was substantial for all tests. Intrauser agreement was 0.73 (0.95 CI 0.64-0.81), interuser agreement 0.71 (0.95 CI 0.63-0.79), and test-retest agreement 0.75 (0.95 CI 0.65-0.86). Average time to record videos and assess POEM scores 7:34 ± 3:37 minutes. CONCLUSIONS: Point-of-care assessment of the microcirculation using IDF video microscopy and POEM scoring appears to be both a feasible and reproducible approach to microcirculatory assessment. Testing of the score in critically ill patients showed substantial agreement within and between investigators, but further studies should validate its utility as a tool to guide shock resuscitation.

Safety and feasibility of sublingual microcirculation assessment in the emergency department for civilian and military patients with traumatic haemorrhagic shock: a prospective cohort study.

OBJECTIVES: Sublingual microcirculatory monitoring for traumatic haemorrhagic shock (THS) may predict clinical outcomes better than traditional blood pressure and cardiac output, but is not usually performed until the patient reaches the intensive care unit (ICU), missing earlier data of potential importance. This pilot study assessed for the first time the feasibility and safety of sublingual video-microscopy for THS in the emergency department (ED), and whether it yields useable data for analysis. SETTING: A safety and feasibility assessment was undertaken as part of the prospective observational MICROSHOCK study; sublingual video-microscopy was performed at the UK-led Role 3 medical facility at Camp Bastion, Afghanistan, and in the ED in 3 UK Major Trauma Centres. PARTICIPANTS: There were 15 casualties (2 military, 13 civilian) who presented with traumatic haemorrhagic shock with a median injury severity score of 26. The median age was 41; the majority (n=12) were male. The most common injury mechanism was road traffic accident. PRIMARY AND SECONDARY OUTCOME MEASURES: Safety and feasibility were the primary outcomes, as measured by lack of adverse events or clinical interruptions, and successful acquisition and storage of data. The secondary outcome was the quality of acquired video clips according to validated criteria, in order to determine whether useful data could be obtained in this emergency context. RESULTS: Video-microscopy was successfully performed and stored for analysis for all patients, yielding 161 video clips. There were no adverse events or episodes where clinical management was affected or interrupted. There were 104 (64.6%) video clips from 14 patients of sufficient quality for analysis. CONCLUSIONS: Early sublingual microcirculatory monitoring in the ED for patients with THS is safe and feasible, even in a deployed military setting, and yields videos of satisfactory quality in a high proportion of cases. Further investigations of early microcirculatory behaviour in this context are warranted. TRIAL REGISTRATION NUMBER: NCT02111109.

Monitoring microcirculation.

The clinical relevance of microcirculation and its bedside observation started gaining importance in the 1990s since the introduction of hand-held video microscopes. From then, this technology has been continuously developed, and its clinical relevance has been established in more than 400 studies. In this paper, we review the different types of video microscopes, their application techniques, the microcirculation of different organ systems, the analysis methods, and the software and scoring systems. The main focus of this review will be on the state-of-art technique, CytoCam-incident dark-field imaging, and the most recent technological and technical updates concerning microcirculation monitoring.

Real-time point of care microcirculatory assessment of shock: design, rationale and application of the point of care microcirculation (POEM) tool.

BACKGROUND: Despite over a decade of research and technological advances, sublingual microcirculatory monitoring has not yet reached clinical utility. Offline analysis is time consuming and occurs away from the patient. A system to assess the microcirculation at the point of care is desirable. We present a novel 5-point grading system (the point of care microcirculation (POEM) scoring system) that can be used at the point of care during non-invasive sublingual microcirculatory monitoring. METHODS: The POEM score is an ordinal scale from 1 (worst) to 5 (best), based on a composite assessment of flow and heterogeneity of four individual sublingual video-microscopy clips. Thirty-two healthcare professionals were trained in how to assign POEM scores. Following training they assigned scores to five test sequences (each consisting of four video clips). They were blinded to clinical status. Inter-user consistency and agreement were assessed using intra-class correlation coefficient (ICC) analysis. In addition, blinded expert scores for 68 video clips were compared to offline computer analysis using traditional microcirculatory parameters including total vessel density (TVD), perfused vessel density (PVD), proportion of perfused vessels (PPV), microcirculatory flow index (MFI) and microcirculatory heterogeneity index (MHI). The time taken to assign each was recorded. RESULTS: Participants showed good inter-rater consistency (ICC 0.83, 95 % CI 0.626, 0.976) and agreement (ICC 0.815, 95 % CI 0.602, 0.974) for assigned POEM scores. Expert scoring of videos correlated with offline values for PVD (R 2 = 0.39; p < 0.05), PPV (R 2 = 0.71; p < 0.001), MFI (R 2 = 0.75; p < 0.001), and MHI (R 2 = 0.68; p < 0.001). POEM scores took less time to assign than conventional offline computer analysis (2 minutes versus 44 minutes). CONCLUSION: We present for the first time a novel 5-point ordinal scale of microcirculatory flow and heterogeneity that can be used at the point of care. It has minimal inter-user variability amongst healthcare professionals after just 1 hour of training. POEM scores take a short time to assign, and correspond well to traditional offline computer-analyzed parameters.

Methods for in vitro functional analysis of iPSC derived cardiomyocytes - Special focus on analyzing the mechanical beating behavior.

A rapidly increasing number of papers describing novel iPSC models for cardiac diseases are being published. To be able to understand the disease mechanisms in more detail, we should also take the full advantage of the various methods for analyzing these cell models. The traditionally and commonly used electrophysiological analysis methods have been recently accompanied by novel approaches for analyzing the mechanical beatingbehavior of the cardiomyocytes. In this review, we provide first a concise overview on the methodology for cardiomyocyte functional analysis and then concentrate on the video microscopy, which provides a promise for a new faster yet reliable method for cardiomyocyte functional analysis. We also show how analysis conditions may affect the results. Development of the methodology not only serves the basic research on the disease models, but could also provide the much needed efficient early phase screening method for cardiac safety toxicology. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

The microcirculation image quality score: development and preliminary evaluation of a proposed approach to grading quality of image acquisition for bedside videomicroscopy.

PURPOSE: Side-stream dark-field microscopy is currently used to directly visualize sublingual microcirculation at the bedside. Our experience has found inherent technical challenges in the image acquisition process. This article presents and assesses a quality assurance method to rate image acquisition quality before analysis. MATERIALS AND METHODS: We identified 6 common image capture and analysis problem areas in sublingual side-stream dark-field videos: illumination, duration, focus, content, stability, and pressure. We created the "Microcirculation Image Quality Score" by assigning a score of optimal (0 points), suboptimal but acceptable (1 point), or unacceptable (10 points) to each category (for further details, go to http://www.MicroscanAnalysis.blogspot.com). We evaluated 59 videos from a convenience sample of 34 unselected, noncritically ill emergency department patients to create a test set. Two raters, blinded to each other, implemented the score. Any video with a cumulative score of 10 or higher (range, 0-60) was considered unacceptable for further analysis. RESULTS: We created the Microcirculation Image Quality Score and applied it to 59 videos. For this particular set of 59 videos, the mean (SD) passing quality score was 1.68 (0.90), and the mean (SD) failing quality score was 15.74 (6.19), with 27 of 59 passing the quality score less than 10. Highest failure occurred from pressure artifact. The interrater agreement for acceptability was assessed using Cohen κ for each category: illumination (κ = 1.0), duration (κ = 1.0), focus (κ = 0.91), content (κ = 0.76), stability (κ = 0.71), and pressure (κ = 0.82) and overall pass-fail rates (score >10) (κ = 0.66). CONCLUSION: Our Microcirculation Image Quality Score addresses many of the common areas where video quality can degrade. The criteria introduced are an objective way to assess the quality of image acquisition, with the goal of selecting videos of adequate quality for analysis. The interrater reliability results in our preliminary study suggest that the Microcirculation Image Quality Score is reasonably repeatable between reviewers. Further assessment is warranted.

Nailfold capillaroscopy in systemic sclerosis: is there any difference between videocapillaroscopy and dermatoscopy?

BACKGROUND: Vasculopathy is known to destroy nailfold capillary pattern (NCP) in systemic sclerosis (SSc). There are several methods for the evaluation of NCP of which the most common are dermatoscopy and videocapillaroscopy (VCAP). No study has been reported in the literature comparing these two techniques for their diagnostic value. OBJECTIVE: To compare the diagnostic value of dermatoscopy and VCAP which are widely used to determine changes in the NCP in SSc patients. METHODS: A total of 382 nailfolds were visualized. NCP was evaluated in 39 SSc patients using dermatoscopy and VCAP. Defined dermatoscopic groups were matched with early, active and late phase NCP groups determined by VCAP for comparisons. RESULTS: Both dermatoscopy and VCAP demonstrated distinct NCP of SSc efficiently. According to dermatoscopic NCP, capillary dilatation, giant capillaries and disrupted vascular configuration were able to be visualized. VCAP revealed early phase NCP in N = 8 (20,5%), active phase in N = 18 (46,2%) and late phase NCP in N = 13 (33.3%) of the patients. Statistical evaluation of grouped data resulted a Cohen kappa value (K) = 0,527. Although VCAP was able to facilitate a more detailed evaluation of NCP, there was no difference between dermatoscopy and VCAP for the identification of distinct NCP in SSc. CONCLUSION: We suggest that dermatoscopy is efficient enough to identify pathognomonic changes in NCP in SSc as well as VCAP and find dermatoscopy as a very easy applicable and convenient method than VCAP although VCAP facilitates a more detailed evaluation of NCP.

Early depth assessment of local burns by videomicroscopy: a novel proposed classification.

PURPOSE: Videomicroscopy is very useful for burn depth assessment in an early phase; however, there is no practical classification that includes complicated anatomic, pathologic, and morphologic findings of burn wounds. The aim of this study was to propose a novel classification to assess burn depth in its early phase easily and reliably by videomicroscopy. METHODS: Forty-four patients with 56 intermediate-depth burn wounds were included. Burn depth was divided into each grade according to our proposed classification, which is composed of five categories based on dermal capillary integrity patterns. The intrarater and interrater reliabilities of the assessment by the second and third authors were evaluated by Cohen's unweighted κ-value. RESULTS: The results of the measurements according to the proposed classification showed an accuracy of 92.9%, sensitivity of 81.8%, and specificity of 100.0%. The intrarater reliability of the second and third authors showed substantial agreement (κ=0.719 and 0.729, respectively). The interrater reliability of the sum of each observer's variable also showed substantial agreement (κ=0.636). CONCLUSION: This pattern analysis system is easy to use even for inexperienced personnel, and is reliable with high accuracy and specificity. Intrarater and interrater statistics also support its reliability and reproducibility.

Mapping 3-D functional capillary geometry in rat skeletal muscle in vivo.

We have developed a novel mapping software package to reconstruct microvascular networks in three dimensions (3-D) from in vivo video images for use in blood flow and O2 transport modeling. An intravital optical imaging system was used to collect video sequences of blood flow in microvessels at different depths in the tissue. Functional images of vessels were produced from the video sequences and were processed using automated edge tracking software to yield location and geometry data for construction of the 3-D network. The same video sequences were analyzed for hemodynamic and O2 saturation data from individual capillaries in the network. Simple user-driven commands allowed the connection of vessel segments at bifurcations, and semiautomated registration enabled the tracking of vessels across multiple focal planes and fields of view. The reconstructed networks can be rotated and manipulated in 3-D to verify vessel connections and continuity. Hemodynamic and O2 saturation measurements made in vivo can be indexed to corresponding vessels and visualized using colorized maps of the vascular geometry. Vessels in each reconstruction are saved as text-based files that can be easily imported into flow or O2 transport models with complete geometry, hemodynamic, and O2 transport conditions. The results of digital morphometric analysis of seven microvascular networks showed mean capillary diameters and overall capillary density consistent with previous findings using histology and corrosion cast techniques. The described mapping software is a valuable tool for the quantification of in vivo microvascular geometry, hemodynamics, and oxygenation, thus providing rich data sets for experiment-based computational models.

Cytodiagnosis through use of a z-axis video by volunteer observers: a promising tool for external quality assessment.

OBJECTIVE: This study examined whether cytological diagnosis through the use of a video, which shows the changing depth of focus in the microscopic field, described as a z-axis video, is useful compared with a still image. METHODS: From 17 cytology preparations of fine needle aspiration of the breast, we made six z-axis videos per case. A frame exhibiting the characteristic features was then extracted from each video and saved as a representative still image. One hundred and twenty-eight volunteer cytotechnologists were randomly divided into two groups of video observers and still image observers. The participants were asked to make a diagnosis of benign, indeterminate, suspicious or malignant without having any clinical information other than the age of the patient. Diagnoses were categorized as 'recommended' or 'unacceptable' according to degree of correlation with histology. RESULTS: The number of definitive diagnoses of 'benign' or 'malignant' were increased in video observers, and indeterminate or suspicious categories were decreased (P = 0.013). The distribution of diagnostic categories in three of the 17 cases was significantly different; the distribution in the remaining cases was similar between the two groups. The z-axis video observers may have selected the definite diagnoses with confidence because they observed valuable microscopic findings by 'focusing through observation'. The average number of 'recommended' diagnoses by individual observers was significantly higher in the video observer group than in the still image observer group (P = 0.016). In contrast, the average number of 'unacceptable' diagnoses was significantly lower (P = 0.019). CONCLUSIONS: A z-axis video is easy to obtain and is therefore expected to become a powerful diagnostic modality for the external quality assessment of clinical cytology and even in the field of primary cytodiagnosis.

Measurement of hemoglobin oxygen saturation using Raman microspectroscopy and 532-nm excitation.

The resonant Raman enhancement of hemoglobin (Hb) in the Q band region allows simultaneous identification of oxy- and deoxy-Hb. The heme vibrational bands are well known at 532 nm, but the technique has never been used to determine microvascular Hb oxygen saturation (So(2)) in vivo. We implemented a system for in vivo noninvasive measurements of So(2). A laser light was focused onto areas of 15-30 microm in diameter. Using a microscope coupled to a spectrometer and a cooled detector, Raman spectra were obtained in backscattering geometry. Calibration was performed in vitro using blood at several Hb concentrations, equilibrated at various oxygen tensions. So(2) was estimated by measuring the intensity of Raman signals (peaks) in the 1,355- to 1,380-cm(-1) range (oxidation state marker band nu(4)), as well as from the nu(19) and nu(10) bands (1,500- to 1,650-cm(-1) range). In vivo observations were made in microvessels of anesthetized rats. Glass capillary path length and Hb concentration did not affect So(2) estimations from Raman spectra. The Hb Raman peaks observed in blood were consistent with earlier Raman studies using Hb solutions and isolated cells. The correlation between Raman-based So(2) estimations and So(2) measured by CO-oximetry was highly significant for nu(4), nu(10), and nu(19) bands. The method allowed So(2) determinations in all microvessel types, while diameter and erythrocyte velocity could be measured in the same vessels. Raman microspectroscopy has advantages over other techniques by providing noninvasive and reliable in vivo So(2) determinations in thin tissues, as well as in solid organs and tissues in which transillumination is not possible.

Videodermoscopy in the evaluation of hair and scalp disorders.

BACKGROUND: The standard methods used to diagnose scalp and hair disorders (eg, simple clinical inspection, pull test, biopsy) vary in sensitivity, reproducibility, and invasiveness. Studies on a few entities suggest that use of dermoscopy can improve clinical accuracy, but further investigation is needed. OBJECTIVES: We sought to: (1) characterize features of several nontumoral scalp and hair conditions using videodermoscopy; and (2) assess the potential usefulness of videodermoscopy in the clinical evaluation of these conditions. METHODS: Images (x20-70 magnification) obtained with videodermoscopy from 220 patients with various scalp and hair disorders and 15 unaffected control subjects were reviewed for distinguishing features. RESULTS: Conditions evaluated included psoriasis (23), seborrheic dermatitis (26), alopecia areata (58), androgenetic alopecia (64), chronic telogen effluvium (7), trichotillomania (12), and primary cicatricial alopecia (30). Clinical features evident to the naked eye were seen in great detail when videodermoscopy was used. Novel features (eg, yellow dots in alopecia areata) were also identified. LIMITATIONS: Findings require confirmation by blinded, prospective investigation. CONCLUSIONS: Use of videodermoscopy in the clinical evaluation of scalp and hair disorders improves diagnostic capability beyond simple clinical inspection and reveals novel features of disease, which may extend clinical and pathogenetic understanding.

A new method for objective identification and measurement of airway lumen in paediatric flexible videobronchoscopy.

BACKGROUND: Accurate measurements of airway and lesion dimensions are important to the developmental progress of paediatric bronchoscopy. The malacia disorders are an important cause of respiratory morbidity in children, but no methods are currently available to measure these lesions or the airway lumen accurately. A new measurement technique is described here. METHODS: The magnification power of a paediatric videobronchoscope was defined and a simple and user friendly computer based program (Image J) was used to develop an objective technique (colour histogram mode technique, CHMT) for measurement of the airway lumen. RESULTS: In vivo intra-observer and inter-observer repeatability coefficients for repeated area measurements from 28 images using the Bland-Altman method were 0.9 mm2 and 1.6 mm2, respectively. The average intraclass correlation coefficient for repeated measurements of area was 0.93. In vitro validation measurements using a 2 mm diameter tube resolved radii measurements to within 0.1 mm (coefficient of variability 8%). An "acceptable result" was defined in 92% of 734 images completed with the CHMT alone and 8% with its modification. The success rate for two of three images being within 10% of each other's area was 100%. Measurements of cricoid cross sectional areas from 116 patients compared with expected airway areas for age derived from endotracheal tube sizes were comparable. CONCLUSIONS: The CHMT method of identifying and measuring airway dimensions is objective, accurate, and versatile and, as such, is important to the future development of flexible videobronchoscopy.

Prosthesis intolerance in patients with transfemoral amputation: a videocapillaroscopic study.

Videocapillaroscopy is a new technique allowing a noninvasive examination of the capillary framework of the skin by using a contact probe with magnifying lenses and a cold-light epiluminescence system. The aim of this article was to investigate, by videocapillaroscopy, the microcirculation of the skin of the stump in 70 consecutive patients with unilateral transfemoral amputation. Patients were divided into two subgroups according to their tolerance (A) or intolerance (B) to a prosthesis with an Icelandic-Swedish-New York socket. Subgroup A included 48 patients, 17 diabetic and 31 nondiabetic, and subgroup B included 22 patients, 16 diabetic and 6 nondiabetic. In subgroup B, the caliber of capillary loops was significantly larger (mean +/-standard deviation, 23.6 +/-2.04 vs. 16.2 +/-1.96 microm; P < 0.001), neoangiogenesis was significantly more frequent (82%vs. 25%, P < 0.001), and the presence of microaneurysms (64%vs. 15%, P < 0.001) and microhemorrhages (36%vs. 4%, P < 0.001) was also more frequent. Surprisingly, some such diabetes-like microvascular changes were also found in the six nondiabetic patients of subgroup B. By using multiple logistic regression analysis, intolerance to the prosthesis was significantly related to microvascular changes (P = 0.001) but not to diabetes (P = 0.601), although diabetes was unequally distributed in the two subgroups.

Suppression of photobleaching-induced artifacts in frequency-domain FLIM by permutation of the recording order.

BACKGROUND: Photobleaching can lead to significant errors in frequency-domain fluorescence lifetime imaging microscopy (FLIM). Existing correction methods for photobleaching require additional recordings and processing time and can result in additional noise. A method is introduced that suppresses the effects of photobleaching without the need for extra recordings or processing. METHODS: Existing bleach correction methods and the method introduced in this report whereby the recording order of the phases is permuted were compared using numerical simulations. RESULTS: Certain orders were found to make measurements virtually insensitive to photobleaching. At 12 recordings, errors in measured phase and modulation depth decreased by a factor 512 and 393, respectively, compared to recordings using sequential recording order. The optimal order is independent of modulation depth, phase, and extent of photobleaching. Thus, the same order can be used for practically all situations. Application of the method in FLIM measurements of EYFP-transfected HeLa cells was found effectively to suppress photobleaching induced artifacts. CONCLUSIONS: In view of the ease of implementation, its inherent robustness, and the possibility to still apply existing correction methods afterward, there is no good reason not to use the permuted recording order presented in this report instead of a sequential order.

Preoperative melanoma thickness determination by 20-MHz sonography and digital videomicroscopy in combination.

OBJECTIVE: To identify accurately thick melanomas preoperatively by means of a combined approach based on sonography and clinical-videomicroscopic evaluation. DESIGN: Ultrasonographic thickness measurement, obtained by means of a 20-MHz B-scanner, and identification of clinical and videomicroscopic variables useful in distinguishing between thick and thin melanomas were performed on a training set of 40 melanomas. An algorithm based on echographic, clinical, and videomicroscopic criteria was constructed to develop a method for preoperative evaluation of melanoma thickness and was validated on a test set of 48 melanomas. SETTING: University medical department. PATIENTS: Eighty-eight patients affected by primary cutaneous melanoma. MAIN OUTCOME MEASURES: Sensitivity and specificity of the algorithm, with the use of sonographic, clinical, and videomicroscopic data, in thick melanoma identification. RESULTS: Echographic thickness was calculated for each lesion. On the training set, 2 clinical and 7 videomicroscopic features were identified for distinction between thick and thin melanomas: nonpalpability, central pigment network, central brown globules, and blotches were characteristic of thin melanomas; clinical regression, localized peripheral pigment network, veil, grayish polygonal areas, and blood vessels were characteristic of thick ones. A coefficient was attributed to each variable and a score was obtained for each lesion. The algorithm, developed for preoperative thickness prediction, was validated on the test set, enabling the distinction of thick melanomas with an 86.7% sensitivity and a 100% specificity. CONCLUSION: The correct classification of all thin melanomas as such renders this approach suitable in clinical practice.

An effective and economical solution for digitizing and analyzing video recordings of the microcirculation.

OBJECTIVE: To assemble an economical system for analysis of microcirculation movies. METHODS: Images of cremaster microvessels were recorded onto sVHS video cassettes. These recordings were digitized onto a Macintosh computer using a MiroMotion DC30 plus video compression card and Adobe Premiere software, which permits video rate (25-30 fps) capture of full-sized (768 x 576 PAL, 640 x 480 NTSC) frames. Once captured, images were analyzed using NIH Image software. RESULTS: Combination of the Macintosh computer, the MiroMotion card, and Adobe Premiere allowed capture of high-resolution images at video rate, with the only limitation to sequence length being available hard-drive space. Captured movies could be directly accessed using the freely available NIH Image software. Use of built-in analysis tools and custom-written macros greatly facilitated rapid, accurate, and reproducible analysis of parameters such as blood flow velocity, leukocyte rolling velocity, and firm adhesion. CONCLUSIONS: Low-priced hardware and software aimed at the home-video enthusiast can be combined with free image-analysis software to provide a powerful image-analysis solution for study of the microcirculation.