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PubMed2005

An integrated platform for automated analysis of protein NMR structures.

Recent developments provide automated analysis of NMR assignments and three-dimensional (3D) structures of proteins. These approaches are generally applicable to proteins ranging from about 50 to 150 amino acids. In this chapter, we summarize progress by the Northeast Structural Genomics Consortium in standardizing the NMR data collection process for protein structure determination and in building an integrated platform for automated protein NMR structure analysis. Our integrated platform includes the following principal steps: (1) standardized NMR data collection, (2) standardized data processing (including spectral referencing and Fourier transformation), (3) automated peak picking and peak list editing, (4) automated analysis of resonance assignments, (5) automated analysis of NOESY data together with 3D structure determination, and (6) methods for protein structure validation. In particular, the software AutoStructure for automated NOESY data analysis is described in this chapter, together with a discussion of practical considerations for its use in high-throughput structure production efforts. The critical area of data quality assessment has evolved significantly over the past few years and involves evaluation of both intermediate and final peak lists, resonance assignments, and structural information derived from the NMR data. Methods for quality control of each of the major automated analysis steps in our platform are also discussed. Despite significant remaining challenges, when good quality data are available, automated analysis of protein NMR assignments and structures with this platform is both fast and reliable.

Data Interpretation, Statistical↗

PubMed2002

Predictive value of short-wavelength automated perimetry: a 3-year follow-up study.

PURPOSE: To determine whether structural changes in the retinal nerve fiber layer (RNFL) and functional abnormalities in short-wavelength automated perimetry (SWAP) can predict the onset of functional losses in standard automated perimetry patients suspected of having glaucoma. DESIGN: Prospective observational case series. PARTICIPANTS: A total of 160 eyes of ocular hypertensive subjects (intraocular pressure greater than 21 mmHg and normal standard automated perimetry) were included in the study. INTERVENTIONS: The subjects underwent RNFL photographic evaluation and SWAP. Standard automated perimetries were repeated after 3 years to evaluate glaucomatous losses. MAIN OUTCOME MEASURES: Onset of glaucomatous defects in conventional automated perimetry after 3 years of follow-up, with or without prior glaucomatous defects in RNFL and SWAP. RESULTS: At the beginning of the study, 77 eyes showed RNFL losses (48%), and 58 eyes showed abnormalities in SWAP (36%). After the 3-year follow-up period, 14 of 77 eyes with RNFL losses had standard automated perimetry abnormalities (predicting sensitivity 93%), whereas 11 of 58 eyes with abnormal SWAP had standard automated perimetry losses (73% sensitivity). CONCLUSIONS: RNFL and SWAP losses are signs of early glaucomatous damage and can predict functional losses in standard automated perimetry.

Adult↗

PubMed2001

Randomized controlled trial of aspiration needle versus automated biopsy device for transjugular liver biopsy.

PURPOSE: The efficacy and safety of transjugular liver biopsy used to obtain liver specimens in patients with coagulation disorders have been widely proven. However, histopathologic examination is not always possible because of fragmented samples provided by the aspiration technique. Recently, an automated device with a Tru-Cut-type needle was designed. In this randomized controlled trial, the use of this new device is compared with the traditional method in terms of efficacy and safety. METHOD: Fifty-six patients were included in the study; 28 were randomized to undergo the aspiration technique and 28 were randomized to undergo the automated biopsy technique. RESULTS: Correct positioning of the device was achieved in 93% of patients undergoing the aspiration technique and 96% of patients undergoing the automated biopsy technique (P = NS). Mean duration of the procedure and total number of passes were significantly higher in the aspiration needle group than in the automated device group (22.6 min +/- 12.6 vs 15.5 min +/- 9.4; P = .03, and 3.3 min +/- 1.9 vs 1.5 min +/- 0.63; P < .001, respectively). The number of portal tracts was significantly higher in the automated device group (4.7 +/- 2.5 vs. 2.7 +/- 3.4; P < .05). Adequate specimens for histopathologic evaluation were obtained in 26 patients in the automated device group and 24 patients in the aspiration needle group (92.8% vs 85.7%; P = NS), but a definite histopathologic diagnosis was more frequently obtained with the automated biopsy device (68% vs 43%; P = .05). No significant differences were observed in complication rates (7.14% vs. 10.7%; P = NS). CONCLUSION: The automated biopsy device for transjugular liver biopsy is more effective than an aspiration needle in obtaining good samples for a definite histologic diagnosis.

Adult↗

PubMed2003

Automated lung segmentation in X-ray computed tomography: development and evaluation of a heuristic threshold-based scheme.

RATIONALE AND OBJECTIVES: To develop and evaluate a reliable, fully-automated lung segmentation scheme for application in X-ray computed tomography. MATERIALS AND METHODS: The automated scheme was heuristically developed using a slice-based, pixel-value threshold and two sets of classification rules. Features used in the rules include size, circularity, and location. The segmentation scheme operates slice-by-slice and performs three key operations: (1) image preprocessing to remove background pixels, (2) computation and application of a pixel-value threshold to identify lung tissue, and (3) refinement of the initial segmented regions to prune incorrectly detected airways and separate fused right and left lungs. RESULTS: The performance of the automated segmentation scheme was evaluated using 101 computed tomography cases (91 thick slice, 10 thin slice scans). The 91 thick cases were pre- and post-surgery from 50 patients and were not independent. The automated scheme successfully segmented 94.0% of the 2,969 thick slice images and 97.6% of the 1,161 thin slice images. The mean difference of the total lung volumes calculated by the automated scheme and functional residual capacity plus 60% inspiratory capacity was -24.7 +/- 508.1 mL. The mean differences of the total lung volumes calculated by the automated scheme and an established, commonly used semi-automated scheme were 95.2 +/- 52.5 mL and -27.7 +/- 66.9 mL for the thick and thin slice cases, respectively. CONCLUSION: This simple, fully-automated lung segmentation scheme provides an objective tool to facilitate lung segmentation from computed tomography scans.

Image Processing, Computer-Assisted↗

PubMed1990

An automated method to prepare cell suspensions from human biopsy samples for immunophenotyping by flow cytometry.

A comparison was made between a manual and automated method for preparing single cell suspensions from various types of human biopsy samples. The automated method uses the shearing action of fluid movement generated by a reciprocating paddle system. When compared on 11 samples, the automated instrument always isolated cells in less time, usually requiring only 15-30 seconds in contrast to 10-15 minutes for the manual method. The time comparisons involved "set up" time of the required minor equipment as well as the time to make a complete single cell suspension from the portion of the biopsy sample sent to the Flow Cytometry Lab so extra cells could be used for other purposes and cryogenically stored for future reference. Cells isolated by the automated method from various B-lymphocytic and T-lymphocytic malignancies were still viable and could be successfully immunophenotyped by flow cytometry. The immunophenotyping results were compared for both cell isolation methods on seven of these samples, and the results were comparable. The automated technique has now been used to satisfactorily immunophenotype more than 50 biopsy samples. The automated method should represent a significant aid for clinical flow cytometry laboratories performing immunophenotyping tests by efficiently preparing single cell suspensions in a few seconds instead of minutes. Furthermore, the automated method uses a closed sterile bag system that helps minimize the exposure of personnel to potential infectious material present in biopsy samples and prevents external contamination of cell suspensions. The automated technique proven successful for immunophenotyping may also be helpful for related procedures involving hematopoietic malignancies such as DNA content analysis and cell functional assays by flow cytometry, as well as other assays such as tissue typing, gene probe, and in vitro chemosensitivity assays.

Antigens, CD↗

PubMed2001

Impact of automation on pharmacist interventions and medication errors in a correctional health care system.

The implementation and impact of an automated check-and-sortation system in a correctional health care system are described. In February 1998 the Managed Health Care Division of the University of Houston College of Pharmacy submitted a proposal to the Texas State Board of Pharmacy for installing an automated check-and-sortation device in its distributive system serving Texas Department of Criminal Justice offenders. The new system would eliminate final visual verification of medication orders by pharmacists and thereby give them more time for in-depth reviews of patient profiles and for recommending clinical interventions. A vendor interested in developing a prototypic automated system was identified, and a disease management training course was developed to enable staff pharmacists to provide evidence-based pharmacotherapy recommendations. Twelve months of data before automation (February 1997 to January 1998) were compared with 16 months of postautomation data (June 1998 to September 1999). The number of clinical interventions increased from 396 per 100,000 medication orders filled before automation to 1075 per 100,000 orders after automation. Dispensing errors decreased from 6.3 to 4.1 per 100,000 medication orders filled. Identified filling errors increased from 224 to 256 per 100,000 orders. The reliability of the automated system was evidenced by a dispensing error rate of 0.6 per 100,000 orders. Implementation of an automated check-and-sortation device in a correctional health care system appeared to reduce dispensing errors and give pharmacists more time to review patient profiles and recommend clinical interventions.

Delivery of Health Care↗

PubMed2003

A comparison of manual and automated systems for soil CO2 flux measurements: trade-offs between spatial and temporal resolution.

Soil respiration is affected by distributions of roots and soil carbon substrates and by temperature and soil water content, all of which vary spatially and temporally. The objective of this paper was to compare a manual system for measuring soil respiration in a temperate forest, which had a greater spatial distribution of measurements (n=12), but poorer temporal resolution (once per week), with an automated system which had poorer spatial distribution (n=3) but superior temporal frequency of measurements (hourly). Soil respiration was measured between 18 June and 21 August, 2002, at the Harvard Forest in central Massachusetts, USA. The fluxes measured within 1 h of each other by these systems were not significantly different. However, extrapolations of the mid-morning manual measurements to daily flux values were consistently lower (averaging 13% lower) than the daily estimates obtained from summing the 24 hourly measurements of the automated system. On the other hand, seasonal flux estimates obtained by interpolating between weekly manual sampling dates or by summing the hourly automated measurements were nearly identical. Underestimates by interpolated weekly manual measurements during some periods were cancelled by overestimates during other periods. Hence, a weekly sampling schedule may be sufficient to capture the most important variation of seasonal efflux of CO(2) from the soil. The larger number of chambers that could be measured with the manual system (larger n) resulted in a smaller 95% confidence interval for characterizing spatial variability within the study area on most dates. However, the greater sampling frequency of the automated system revealed rapid responses of soil respiration to wetting events, which permitted better empirical modelling of the effects of soil temperature and moisture on soil respiration than could have been achieved with the manual sampling system. Most of the positive residuals of a function that predicts soil respiration based on temperature were from fluxes measured within 12 h of a rain event, and the residuals were positively correlated with water content of the O horizon. The automated system also demonstrated that Q(10) values calculated for diel variation in soil temperature over a few days were not significantly different than Q(10) values for the entire 3 month summer sampling period. In summary, a manual system of numerous, spatially well-distributed flux chambers measured on a weekly basis may be adequate for measuring seasonal fluxes and may maximize confidence in the characterization of spatial variance. The high temporal frequency of measurements afforded by automation greatly improves the ability to measure and model the effects of rapidly varying water content and temperature. When the two approaches can be combined, the temporal representativeness of the manual measurements can be tested with the automated measurements and the spatial representativeness of the automated measurements can be tested by the manual measurements.

Carbon Dioxide↗

PubMedDate not supplied

Improving tissue classification in MRI: a three-dimensional multispectral discriminant analysis method with automated training class selection.

PURPOSE: To improve the reliability, accuracy, and computational efficiency of tissue classification with multispectral sequences [T1, T2, and proton density (PD)], we developed an automated method for identifying training classes to be used in a discriminant function analysis. We compared it with a supervised operator-dependent method, evaluating its reliability and validity. We also developed a fuzzy (continuous) classification to correct for partial voluming. METHOD: Images were obtained on a 1.5 T GE Signa MR scanner using three pulse sequences that were co-registered. Training classes for the discriminant analysis were obtained in two ways. The operator-dependent method involved defining circular ROIs containing 5-15 voxels that represented "pure" samples of gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF), using a total of 150-300 voxels for each tissue type. The automated method involved selecting a large number of samples of brain tissue with sufficiently low variance and randomly placed throughout the brain ("plugs"), partitioning these samples into GM, WM, and CSF, and minimizing the amount of variance within each partition of samples to optimize its "purity." The purity of the plug was estimated by calculating the variance of 8 voxels in all modalities (T1, T2, and PD). We also compared "sharp" (discrete) measurements (which classified tissue only as GM, WM, or CSF) and "fuzzy" (continuous) measurements (which corrected for partial voluming by weighting the classification based on the mixture of tissue types in each voxel). RESULTS: Reliability was compared for the operator-dependent and automated methods as well as for the fuzzy versus sharp classification. The automated sharp classifications consistently had the highest interrater and intrarater reliability. Validity was assessed in three ways: reproducibility of measurements when the same individuals were scanned on multiple occasions, sensitivity of the method to detecting changes associated with aging, and agreement between the automated segmentation values and those produced through expert manual segmentation. The sharp automated classification emerged as slightly superior to the other three methods according to each of these validators. Its reproducibility index (intraclass r) was 0.97, 0.98, and 0.98 for total CSF, total GM, and total WM, respectively. Its correlations with age were 0.54, -0.61, and -0.53, respectively. Its percent agreement with the expert manually segmented tissue for the three tissue types was 93, 90, and 94%, respectively. CONCLUSION: Automated identification of training classes for discriminant analysis was clearly superior to a method that required operator intervention. A sharp (discrete) classification into three tissue types was also slightly superior to one that used "fuzzy" classification to produce continuous measurements to correct for partial voluming. This multispectral automated discriminant analysis method produces a computationally efficient, reliable, and valid method for classifying brain tissue into GM, WM, and CSF. It corrects some of the problems with reliability and computational inefficiency previously observed for operator-dependent approaches to segmentation.

Adult↗

PubMed2005

Diagnostic performance of a 3-D automated quantification method of dopamine D2 receptor SPECT studies in the differential diagnosis of parkinsonism.

BACKGROUND: Assessment of post-synaptic D2 receptors with 123I-IBZM SPECT is helpful in distinguishing idiopathic (IPS) from other parkinsonian syndromes (non-IPS). AIM: To evaluate the diagnostic performance of a recently introduced three-dimensional automated quantification method in a large group of parkinsonian patients. METHODS: IBZM SPECT was performed in 101 consecutive patients with IPS (n = 49) and non-IPS (n = 52). Striatal/frontal cortex binding ratios were assessed by a standard manual quantification method and by the automated method. For the latter patient studies were registered to a mean template of healthy controls (n = 13). IBZM binding was calculated from a 3-D volume-of-interest map established on the normal template. The diagnostic performance of the automated and manual approaches were assessed by receiver operating characteristic (ROC) analyses. RESULTS: Specific striatal binding ratios of both quantification methods showed a close linear relationship (y = 0.81x + 0.1188; R2 = 0.8062). At optimal decision thresholds sensitivity and specificity were 87% and 90% for the automated, and 85% and 90% for the manual method, respectively. The area under the ROC curve was 0.92 for the automated and 0.93 for the manual method, showing no statistical difference. The area under the ROC curve corresponding to a false positive fraction from 0% to 20% was 0.163 for the automated and 0.166 for the manual evaluation. CONCLUSIONS: The diagnostic performance of an automated 3-D quantification method for IBZM SPECT studies has been shown to be equal to, or even better than, a standard manual technique. Advantages of automated quantifications are observer independence and fast processing times. This method may be also used as a platform for processing large data sets/multicentre studies in order to objectively evaluate basal ganglia disorders.

Adult↗

PubMed2004

Effect of digital cellular phones on tachyarrhythmia analysis of automated external defibrillators.

OBJECTIVES: Emergency services personnel, family members, laypersons or patients often carry and use mobile phones on sites of emergencies. As there are reported effects on implanted pacemakers and cardioverter defibrillators, the influence of digital cellular phones on automated external defibrillators was studied. METHODS: Twelve automated external defibrillator models were bench tested for their correct decision to or not to advise a shock, while being exposed to electromagnetic interference from a handheld cellular phone with 2 W or a portable cellular phone with 8 W transmitting power. The phones were programmed by a special subscriber identity module card to maximum output power with a carrier frequency of 906.2 MHz. The tests were conducted with a burst frequency of 217 Hz in speech mode and 2-8 Hz in discontinuous transmitting exchange mode. The sensitivity and specificity of electrocardiogram analysis systems were tested, with shockable and non-shockable rhythms provided by an electrocardiogram simulator and on two human subjects with normal sinus rhythm. RESULTS: A total of 8640 tests were recorded, each automated external defibrillator was tested a total of 720 times. The automated external defibrillators demonstrated a sensitivity of 100% and a specificity of 100%, representing a positive likelihood ratio of 8641 and a negative likelihood ratio of 0.000. In this setting all automated external defibrillators analysed correctly even under worst-case testing conditions, and performed excellently without any single failure. In some devices, voice prompts were distorted beyond comprehension, as the coil of the automated external defibrillator speaker received the pulsed signals. CONCLUSION: Shock advisory systems of automated external defibrillators are not susceptible to electromagnetic interference of 900 MHz cellular phones. Voice prompts, however, could be distorted by the operation of nearby digital mobile phones. During automated external defibrillator training this issue needs to be addressed.

Cell Phone↗

PubMed1997

Evaluation of performance of the RIBA processor system for automated analysis of the strip immunoblot assay for detection of antibodies to hepatitis C virus.

The performance of a new automated analyzer for the processing and interpretation of the RIBA Strip Immunoblot Assay (SIA), used in the diagnosis of hepatitis C virus (HCV) infection, was evaluated. Laboratory performance of the RIBA SIA was compared with that of two manually processed supplementary anti-HCV tests (RIBA HCV 3.0 SIA and INNO-LIA HCV Antibody III). Specificity of the automated processing of SIA was 100% for 90 selected anti-HCV-negative samples. On the other hand, 119 of 120 (99.2%) previously confirmed anti-HCV-positive samples were also positive when assayed on the automated processor. Results for all specimens except one (51 of 52) were concordant for manual and automated RIBA, while 15 of 68 sera tested with automated RIBA and the INNO-LIA assay showed different patterns of reactivity. Three HCV sensitivity panels and one seroconversion panel were also compared. The results show a high sensitivity for SIA NS3- and NS5-encoded antigens. Moreover, data obtained for the anti-HCV seroconversion panel and for samples with borderline or discordant anti-HCV enzyme-linked immunosorbent assay results suggest that bands with a relative intensity of >0.5 on the automated analyzer (theoretically negative) should be evaluated with care. Coefficients of variability ranged from 9 to 14.8% in an interassay reproducibility study. Overall, the performance of the automated analysis of SIA is comparable to that of the manual RIBA assay. The new automated processor for SIA bands proved to be sensitive and specific. Its use makes the optical scoring of bands unnecessary by indicating relative intensity values, which could be particularly useful in the follow-up care of anti-HCV-positive patients receiving antiviral therapy.

Electronic Data Processing↗

PubMed1997

Comparison of manual and automated cell counts in EDTA preserved synovial fluids. Storage has little influence on the results.

OBJECTIVE: To determine the precision and agreement of synovial fluid (SF) cell counts done manually and with automated counters, and to determine the degree of variability of the counts in SF samples, kept in the tubes used for routine white blood cell (WBC) counts--which use liquid EDTA as anticoagulant--at 24 and 48 hours at 4 degrees C, and at room temperature. METHODS: To determine precision, cell counts were repeated 10 times--both manually and by an automated counter--in a SF sample of low, medium, and high cellularity. The variances were calculated to determine the interobserver variation in two manual (M1,M2) and two automated cell counts (C1,C2). The agreement between a manual (M1) and automated counter (C1) results, was analysed by the Bland and Altman method and the difference against the mean of the two methods was plotted. Then, the mean difference between the two methods was estimated and the standard deviation of the difference. To determine the effects of storage, SF samples were kept in a refrigerator at 4 degrees C, and at room temperature; cell counts were done manually (M1) and automatically (C1) at 24 and 48 hours and the changes analysed by the Bland and Altman method. The variances were compared using an F test. RESULTS: (1) Precision. With the manual technique, the coefficients of variation were 27.9%, 14%, and 10.7% when used for counting the SF with low (270), medium (6200), and high cellularities (25,000). With the automated technique the coefficients of variation were 20%, 3.4%, and 2.9% in the same SF samples. In the fluids of medium and high cellularity, the variances of the automated cell counts were significatively lower (F test, p < 0.002) than those of the manual counts. (2) Interobserver variation. The variance between C1 and C2 (25 SF) was significatively lower (F test, p < 0.002) than that of the manual counts (41 SF). (3) Agreement between the two techniques (100 SF). For cellularities above 2000 cells/mm3, the manual method gave results between +10% to -34% of the results obtained by the coulter. For cellularities below 2000 cells/mm3, manual cell counts were between +60 to -1280 cells/mm3 of those obtained by the automated counter. (4) Influence of storage. The coulter counts of SF samples preserved at 4 degrees C showed less variance (F test, p < 0.05) than the manual counts. The worst results were obtained in manual counts of SF samples kept at room temperature; these samples at 48 hours showed a variation between -47% to 42% of the initial results. CONCLUSIONS: Automated cell count of the SF offers advantages: it gives higher precision and consumes less time. The stability of the samples preserved in the EDTA tubes used for routine WBC counts is of additional interest, because if delay cannot be avoided, the results of the WBC counts are still accurate at 24 and even at 48 hours, at least for clinical purposes.

Blood Preservation↗

PubMed2002

Automated analysis of data is inferior to visual analysis of ambulatory sleep apnea monitoring.

BACKGROUND: Many ambulatory sleep apnea monitoring devices are equipped with software which allows an automated analysis of data as well as a visual analysis. OBJECTIVE: The Merlin system which records heart rate, snoring sound, efforts, oronasal flow, body position and oxygen saturation was investigated to identify proper parameter settings for the automated analysis and to compare the automated with the visual analysis in patients with mild obstructive sleep apnea syndrome (OSAS). Sensitivity and specificity of the visual and automated analysis of ambulatory monitoring in comparison with visual polysomnographic (PSG) analysis were determined. METHODS AND RESULTS: First, we tried to find the optimal parameters for the automated analysis, using 7 different settings in 17 OSAS patients. Furthermore, we applied the optimized setting to 66 OSAS patients who were admitted (age 50.9 +/- 9.9 years, BMI 32.9 +/- 5 kg/m(2)), and compared the results with the visual analysis of raw data. The patients slept for one night in the sleep laboratory with Merlin and PSG simultaneously to compare the visual and automated analysis of Merlin data with results from the visual analysis of PSG. Automated analysis leads to an underestimation of the respiratory disturbance index (RDI; p < 0.001) compared with both the visual analysis and results of PSG. Using a cutoff level of 5 apneas and hypopneas/h for the diagnosis of OSAS, the sensitivity of Merlin with the automated analysis is 40.6% and the specificity is 100%. With a cutoff level of 15/h, sensitivity and specificity rose to 91.3 and 100%, respectively, which is comparable to the visual analysis. CONCLUSION: Merlin is a reliable device for detection of sleep-related breathing disorders, but recordings should be analyzed visually, especially in patients with a low RDI.

Adult↗

PubMed2003

Automated measurement of microaneurysm turnover.

PURPOSE: An automated system for the measurement of microaneurysm (MA) turnover was developed and compared with manual measurement. The system analyses serial fluorescein angiogram (FA) or red-free (RF) fundus images; fluorescein angiography was used in this study because it is the more sensitive test for MAs. Previous studies have shown that the absolute number of MAs observed does not reflect the dynamic temporal nature of the MA population. In this study, almost half of the MAs present at baseline had regressed after a year and been replaced by new lesions elsewhere. METHODS: Two clinical datasets were used to evaluate the performance of the automated turnover measurement system. The first consisted of 10 patients who had two fluorescein angiograms acquired a year apart. These data were analyzed, both manually and using the automated system, to investigate the inter- and intraobserver variations associated with manual measurement and to assess the performance of the automated system. The second dataset contained FAs from a further 25 patients. This dataset was analyzed only with the automated system to investigate some properties of microaneurysm turnover, in particular the differing detection sensitivities of new, static and regressed microaneurysms. RESULTS: Manual measurements exhibited large inter- and intraobserver variation. The sensitivity and specificity of the automated system were similar to those of the human observers. However, the automated measurements were more consistent-an important condition for accurate turnover quantification. Regressed MAs were more difficult to detect reliably than new MAs, which were themselves more difficult to detect reliably than static MAs. CONCLUSIONS: The automated system was shown to be fast, reliable, and repeatable, making it suitable for processing large numbers of images. Performance was similar to that of trained manual observers.

Adult↗

PubMedDate not supplied

Sonographically guided core biopsy of the breast: comparison of 14-gauge automated gun and 11-gauge directional vacuum-assisted biopsy methods.

OBJECTIVE: To compare the outcomes of 14-gauge automated biopsy and 11-gauge vacuum-assisted biopsy for the sonographically guided core biopsies of breast lesions. MATERIALS AND METHODS: We retrospectively reviewed all sonographically guided core biopsies performed from January 2002 to February 2004. The sonographically guided core biopsies were performed with using a 14-gauge automated gun on 562 breast lesions or with using an 11-gauge vacuum-assisted device on 417 lesions. The histologic findings were compared with the surgical, imaging and follow-up findings. The histologic underestimation rate, the repeat biopsy rate and the false negative rates were compared between the two groups. RESULTS: A repeat biopsy was performed on 49 benign lesions because of the core biopsy results of the high-risk lesions (n = 24), the imaging-histologic discordance (n = 5), and the imaging findings showing disease progression (n = 20). The total underestimation rates, according to the biopsy device, were 55% (12/22) for the 14-gauge automated gun biopsies and 36% (8/22) for the 11-gauge vacuum-assisted device (p = 0.226). The atypical ductal hyperplasia (ADH) underestimation (i.e., atypical ductal hyperplasia at core biopsy and carcinoma at surgery) was 58% (7/12) for the 14-gauge automated gun biopsies and 20% (1/5) for the 11-gauge vacuum-assisted biopsies. The ductal carcinoma in situ (DCIS) underestimation rate (i.e., ductal carcinoma in situ upon core biopsy and invasive carcinoma found at surgery) was 50% (5/10) for the 14-gauge automated gun biopsies and 41% (7/17) for the 11-gauge vacuum-assisted biopsies. The repeat biopsy rates were 6% (33/562) for the 14-gauge automated gun biopsies and 3.5% (16/417) for the 11-gauge vacuum-assisted biopsies. Only 5 (0.5%) of the 979 core biopsies were believed to have missed the malignant lesions. The false-negative rate was 3% (4 of 128 cancers) for the 14-gauge automated gun biopsies and 1% (1 of 69 cancers) for the 11-gauge vacuum-assisted biopsies. CONCLUSION: The outcomes of the sonographically guided core biopsies performed with the 11-gauge vacuum-assisted device were better than those outcomes of the biopsies performed with the 14-gauge automated gun in terms of underestimation, rebiopsy and the false negative rate, although these differences were not statistically significant.

Adolescent↗

PubMedDate not supplied

Automated techniques in haematology.

BACKGROUND: Manual techniques have been mostly in use in developing countries until recently because of its low cost even though it is laborious. Many laboratories are however changing to automated techniques since many samples can be analysed within a short time. It is likely that more laboratories will use these instruments either as semi automated or fully automated multichannel instruments. There is therefore a need for laboratories to become more responsive to the needs of physicians making request by providing help in the presentation and interpretation of results. METHOD: Available literature on automation in Haematology was sourced for using both manual library search and Medline search. RESULTS: Quality control in automated blood cell counts and related topics are extensively researched but there is still dearth of knowledge on automation in other areas of Haematology and on the clinical implications of automation. CONCLUSION: It is therefore necessary to make provision for automated facilities in laboratories in view of the high precision and cost effectiveness of these machines. This review is geared towards a critical look at this technology and its application to disease states.

Autoanalysis↗

PubMed1992

Miles Technicon H.2 automated hematology analyzer.

Automated hematology analyzers are used in all large hospitals and most commercial laboratories, as well as in most smaller hospitals and laboratories, to perform complete blood counts (including white blood cell, red blood cell, and platelet counts; hemoglobin concentration; and RBC indices) and white blood cell differential counts. Our objectives in this study are to provide user guidance for selecting, purchasing, and using an automated hematology analyzer, as well as to present an overview of the technology used in an automated five-part differential unit. Specifications for additional automated units are available in ECRI's Clinical Laboratory Product Comparison System. We evaluated the Miles Technicon H.2 unit and rated it Acceptable. The information in this Single Product Evaluation is also useful for purchasing other models; our criteria will guide users in assessing components, and our findings and discussions on some aspects of automated hematology testing are common to many available systems. We caution readers not to base purchasing decisions on our rating of the Miles unit alone, but on a thorough understanding of the issues surrounding automated hematology analyzers, which can be gained only by reading this report in its entirety. The willingness of manufacturers to cooperate in our studies and the knowledge they gain through participating lead to the development of better products. Readers should refer to the Guidance Section, "Selecting and Purchasing an Automated Hematology Analyzer," where we discuss factors such as standardization, training, human factors, manufacturer support, patient population, and special features that the laboratory must consider before obtaining any automated unit; we also provide an in-depth review of cost issues, including life-cycle cost analyses, acquisition methods and costs of hardware and supplies, and we describe the Hemacost and Hemexmpt cost worksheets for use with our PresValu and PSV Manager CAHDModel software. Readers should also review the Clinical and Technical Overview and the articles "Miles Technicon H.2 Reports" and "Developing the Evaluation Reference Method."

Blood Cell Count↗

PubMed1998

Semi-automated renal region of interest selection method using the double-threshold technique: inter-operator variability in quantitating 99mTc-MAG3 renal uptake.

In calculating the relative and absolute renal uptake of technetium-99m mercaptoacetyltriglycine (MAG3), inter-operator variability in the assignment of the renal region of interest (ROI) is a critical factor. Our goal was to develop a semi-automated method of assigning the renal ROI and then to compare the inter-operator variability in calculating the percent injected dose (%ID) in the kidney at 1-2 min, using semi-automated versus manual ROIs. The manual ROIs were drawn independently by three operators (A, B and C). Operator A had about 20 years, experience in nuclear medicine, while operators B and C respectively had 3 years and 1 year of experience. In the semi-automated renal ROI selection method using the double-threshold technique, the operators only click around the centre of each kidney. The same three operators processed the ROIs using this double-threshold method on 1-2 min images. The semi-automated method failed in three kidneys with very markedly reduced function owing to superimposition by liver or spleen. Inter-operator reproducibility in the remaining 59 kidneys was estimated using manual and semi-automated ROIs. With manual ROIs, the %ID (mean+/-standard error of mean) was 4.32+/-0.167 for A, 4. 14+/-0.165 for B and 3.28+/-0.139 for C. Although there was good correlation among them, these values were significantly different (P<0.0001). Using semi-automated ROIs, the %ID was 4.38+/-0.160 for three operators. No significant difference was observed. Complete reproducibility was shown in 58 of 59 kidneys; the %ID difference of the remaining kidney was only 1.2%. The lowest %ID of all the kidneys successfully detected using the semi-automated method was 0. 77%. The semi-automated renal ROI selection method using the double-threshold technique displays good detectability of the renal contour. The renal uptake calculated using this method is reproducible and acceptable in routine clinical practice.

Adolescent↗