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To achieve full implementation of the digital radiology department or of picture archive and communication systems, an efficient digital image archive must be constructed. This paper discusses the use of statistical-caching techniques within an image archive. In addition, the results of computer modeling will be used to demonstrate the advantages of this approach.
The analysis of DNA extracted from archival clinical specimens using polymerase chain reaction represents the basis of a variety of research and diagnostic protocols in medicine. However, the selection of optimal DNA extraction method is critical if such an analysis is to be successful. Recently, we have evaluated a number of rapid DNA extraction protocols in order to find the most suitable method for routine processing of the most common archival materials in pathological and cytological laboratories: paraffin-embedded tissues and Papanicolaou- or Giemsa-stained smears. Our results demonstrate that rapid DNA extraction methods have comparable DNA extraction efficiencies with standard DNA isolation protocols on archival clinical specimens with the exception of Giemsa-stained smears.
Communication and co-operation in healthcare and welfare requires certain Trusted Third Party (TTP) services describing both status and relation of communicating principals as well as their corresponding keys and attributes. Additional TTP services are needed to provide trustworthy information about dynamic issues of communication and co-operation such as time and location of processes, workflow relations, and system behaviour. Electronic signatures based on asymmetric cryptography are important means for securing the integrity of a message or file as well as for accountability purposes including non-repudication of both origin and receipt. These electronic signatures along with certified time stamps are especially important for electronic health records (EHR), electronic archives in general, and other typical purposes of a long-lasting storage. Apart from technical storage problems (e.g. lifetime of the storage devices), this paper needs to look for mechanisms of e.g. re-signing of messages, archive details, or whole archives.
In modern medicine the well structured patient data set, fast access to it and reporting capability become an important question. With the dynamic development of information technology (IT) such question is solved via building electronic patient record (EPR) archives. We then obtain fast access to patient data, diagnostic and treatment protocols etc. It results in more efficient, better and cheaper treatment. The aim of the work was to design a uniform Electronic Patient Record, implemented in cardio.net system for telecardiology allowing the co-operation among regional hospitals and reference centers. It includes questionnaires for demographic data and questionnaires supporting doctor's work (initial diagnosis, final diagnosis, history and physical, ECG at the discharge, applied treatment, additional tests, drugs, daily and periodical reports). The browser is implemented in EPR archive to facilitate data retrieval. Several tools for creating EPR and EPR archive were used such as: XML, PHP, Java Script and MySQL. The separate question is the security of data on WWW server. The security is ensured via Security Socket Layer (SSL) protocols and other tools. EPR in Cardio.net system is a module enabling the co-work of many physicians and the communication among different medical centers.
The Archive of the Indigenous Languages of Chiapas is an electronic database documenting the three principal Indian languages of Chiapas, Mexico. This report describes the design philosophy behind the archive, intended to distribute its results in digital form via the Internet. It illustrates some of the products of the Archive, ranging from standard linguistic description and lexicography, through semi-experimental elicitation, to ethnographically situated interaction characterized by different sorts of speech genre. It also discusses presentational and ethical issues derived from electronic distribution of digital media in linguistic documentation.
Communication and co-operation in the domain of healthcare and welfare require a well-defined set of security services based on a Public Key Infrastructure and provided by a Trusted Third Party (TTP). These services describe both status and relation of communicating principals, corresponding keys and attributes, and the access rights to applications and data. Additional services are needed to provide trustworthy information about dynamic issues of communication and co-operation such as time and location of processes, workflow relations, and system behaviour. Legal, social, behavioural and ethical requirements demand securely stored patient information and well-established access tools and tokens. Electronic (and more specifically digital) signatures--as important means for securing the integrity of a message or file--along with certified time stamps or time signatures are especially important for purposes of data storage in electronic archives and electronic health records (EHR). While just mentioning technical storage problems (e.g. lifetime of the storage devices, interoperability of retrieval and presentation software), this paper identifies mechanisms of securing data items, files, messages, sets of archived items or documents, electronic archive structures, and life-long electronic health records. Other workshop contributions will demonstrate related aspects of policies, patient privacy, and privilege management.
The author uses archival material, mainly the letters exchanged between Jones and Strachey in the fifties, when Jones was writing his biography of Freud and Strachey was working on the Standard Edition. He shows the complexity of the interaction between these two men; the more or less conscious ambivalences, motivations and resentments against the so-called Freudian establishment of that time. This per se can help us to understand how a 'certain image' of Freud was created in Great Britain during those years and the reasons for its authoritative persistence. Yet the paper touches on more general issues such as those of the fascination with psychoanalytic archives and the more or less accepted and admitted unconscious motivations of the interpreters of these documents too, not excluding myself. The conclusion reached is that even psychoanalytical documents do not rest in a peaceful Arcadia and that archives cannot be considered as the Arcadia of documents--at least not in the ways that Arcadia has always been considered and interpreted, misleadingly, even in two paintings by Poussin, which I refer to in my paper. These in reality remind us that in Arcadia there is death too. Even the memory that the documents should help us to conserve is ineluctably bound to loss, dissemination, mutilation and uncertainty, and therefore must also face the presence of death also.
Archival slides are a potentially useful source of DNA for mutation analyses in large population-based studies. However, it is unknown whether specimen age or histological stains alter the accuracy of Taq polymerase or induce secondary mutations in sample DNA. To address this question, we evaluated five methods for extraction of genomic DNA from archival bone marrow slides of 17 leukemia patients and analyzed exons 1 and 2 of the N- and K-ras genes for the presence of mutations. Of the five methods, optimal DNA purification was achieved by boiling and phenol:chloroform extraction. N-and K-ras exons 1 and 2 were independently amplified using 35 cycles of PCR, and 6-12 clones for each exon were isolated and individually sequenced for each patient. Mutations were confirmed by repeat extraction, cloning, and sequencing. Sixteen of 17 patient samples were successfully amplified (94%), including slides up to 29 years old. Twelve slides had been stained with Wright-Giemsa, I stained with toluidine blue, and 4 were unstained. A total of 16 single-base mutations were identified of 33,840 nucleotides sequenced. No insertions or deletions were identified. Six of 16 single-base mutations were previously described activating mutations in codon 13 of N-ras exon 1. The 10 other mutations were in other regions of the N- and K-ras genes and were not reproduced after repeat extraction, cloning, and sequencing. The frequency of these other alterations was I of 3384 bp. This value is comparable with the inherent error frequency for Taq polymerase. Our findings suggest that high fidelity DNA amplification can be achieved using archival hematological slides as old as 29 years and can be reliably used in genetic analyses.
BACKGROUND: The AutoPap 300 QC System is an automated device for the analysis of conventional cervical cytology slides. The AutoPap selects an enriched population of cases for quality control review. These studies evaluated the overall sensitivity of AutoPap device to a wider variety of cytologic abnormalities than could be analyzed in the prospective portion of the clinical trials. METHODS: At five clinical trial sites, positive cases were selected from: 1) archives (historic sensitivity study) or 2) current positive cases (current archive sensitivity study). Cases were analyzed by the AutoPap System along with matched negative cases and stratified into detection deciles by instrument score for each diagnostic category. RESULTS: For the historic sensitivity study, the percentages of cases present within the top 10% instrument scores were as follows: atypical glandular cells of undetermined significance (AGUS): 33.7% (n = 243); low grade squamous intraepithelial lesion (LSIL): 57% (n = 412); high grade squamous intraepithelial lesion (HSIL): 81.6% (n = 385); and carcinoma: 77.7% (n = 139). For the current archive sensitivity study, the percentage of cases within the top 10% of instrument scores were as follows: atypical squamous cells of undetermined significance (ASCUS): 37.6% (n = 205); AGUS: 27.3% (n = 22); LSIL: 53.7% (n = 410); HSIL: 80.7% (n = 202); and carcinoma: 62.5% (n = 8). Sensitivities at higher percentiles proportionately were greater. CONCLUSIONS: The AutoPap 300 QC System is detection sensitive, particularly at the level of LSIL and greater. When coupled with the data from the prospective intended use study, these results provided confirmation of the instrument's ability to enhance the false-negative detection rate significantly when compared with a 10% random case selection process. In addition, high sensitivities to all categories of abnormality suggest the possibility of using such instrumentation as a primary screening device for cervical cytology.
The histopathology archive represents a vast, well-characterized source of specimens covering virtually every disease and is available for molecular biological investigation. The archive has in recent years become widely used for molecular genetic analysis and DNA can be routinely extracted from formalin-fixed, paraffin-embedded tissue. More recently, archival specimens have become a source of material for extensive analysis of mRNA expression utilizing DNA microarrays, real-time quantitative reverse transcriptase polymerase chain reaction (PCR), and in situ hybridization and amplification techniques. These techniques will enable a greater understanding of the changes that occur in gene function during every stage of the development of disease and will lead to better diagnosis, better evaluation of prognosis, and better treatment through targeted therapeutic regimes.
Mass spectrometry was applied to identify protein spots excised from an archived two-dimensional polyacrylamide gel that had been dried and stored for eight years at room temperature. All proteins were successfully identified. Detailed characterization of protein digests by matrix-assisted laser desorption/ionization (MALDI) peptide mapping, nanoelectrospray tandem mass spectrometry and MALDI-quadrupole time-of-flight mass spectrometry revealed no evidence of protein degradation or modifications that could hamper identification of proteins in a sequence database. The experiment with a model protein demonstrated that the pattern of tryptic peptides and the yield of individual peptides were not noticeably changed in the in-gel digest of the archived protein spot compared to the digest of the spot excised from a fresh gel. Thus, the characterization of "archived proteomes" has the potential to advance proteomic research without repeating "wet" biochemistry experiments, that had been perfected in the laboratory years ago.
In the last 5 years, HLA class II genotyping methods have been adapted for genotyping of class II loci in rhesus macaques. Since previously published typing protocols were used on samples that were collected and stored under ideal conditions, it was of interest to determine if these methods were adequate for genotyping a large collection of archival samples from which DNA had been isolated and stored under various conditions. Established macaque DQA1 typing protocols were modified to optimize the typing procedure and enhance the ability to successfully genotype DNA from samples that were of poor quality and/or quantity. Long-term storage of whole-blood buffy coats or stored DNA extracted from whole-blood buffy coats did not affect typing success; however, amplification and typing of DNA extracted from archival samples of plasma were difficult and resulted in a low success rate. This suggests that amplification and DQA1-genotyping of archival samples is possible with a modified protocol, but is influenced by the age and source of the sample, and to a lesser extent, the method used to extract DNA from sample substrates.
BACKGROUND: The t(14;18)(q32;q21) translocation is present in about 85% of follicular lymphomas (FL) and can be identified using fluorescence in situ hybridization (FISH). In the diagnostic laboratory setting, the cytologic archival material consists of stained slides, and only rarely is material saved for molecular testing. The authors proposed FISH for FL using Papanicolaou-stained archival cytology material as a practical ancillary technique for diagnosing FL. METHODS: Cases included 35 FL, 6 small lymphocytic lymphomas/chronic lymphocytic leukemias (SLL/CLL), 4 mantle cell lymphomas (MCL), 4 marginal zone lymphomas (MZL), 1 lymphoplasmacytic lymphoma (LPL), and 10 reactive lymphoid tissues (RLT). FISH was performed on Papanicolaou-stained archival cytology slides using probes for immunoglobulin heavy chain (IGH) on chromosome 14 and BCL2 on chromosome 18. RESULTS: In all, 25 of 32 (81%) FL cases exhibited the t(14;18) translocation, whereas 7 of 32 (19%) lacked the translocation. No cases of non-FL were positive for t(14;18). This series shows a sensitivity of 81% and specificity of 100% for detecting the t(14;18) translocation as a diagnostic tool in FL. CONCLUSIONS: When performed on Papanicolaou-stained cytology slides, FISH for t(14;18) is relatively sensitive and quite specific for FL. These findings are similar to those reported on other specimens, such as paraffin-embedded tissue and unstained cytology slides. The authors proposed that their technique would allow the pathologist and clinician the flexibility to utilize previously stained fine-needle aspiration slides for FISH evaluation.
Altered glycosylation is a feature of many solid tissue diseases such as ulcerative colitis, Crohn's disease, cancer, and connective tissue disorders. Conventionally, oligosaccharide changes have been studied by immunohistochemical techniques. We have adapted existing techniques, developed for purified protein preparations, to allow the release of intact oligosaccharides from archival tissues, so that the oligosaccharides may be structurally characterized. In our study, sections cut from paraffin-wax blocks were dewaxed and oligosaccharides were released using hydrazine and labeled with 2-aminobenzamide. Sialylated oligosaccharides were compared by passing through a GlycoSep C divinylbenzene anion exchange resin column and neutral oligosaccharides were compared by passing through a BioGel P4 column. The oligosaccharide profiles obtained from the same fresh frozen versus archival paraffin-wax-embedded, normal liver, and tumor tissues showed remarkable similarity in terms of their sialylated and neutral structures. Matrix-assisted laser desorption ionization mass spectrometry has shown that the oligosaccharides are not affected by fixation in formalin and storage in paraffin wax. The results indicate that while the proteins themselves may be denatured, oligosaccharides are not adversely affected by fixation in formalin and storage in paraffin wax. By applying these methods, oligosaccharides from archival tissues, where the natural history of the disease has been followed, may now be liberated and structurally characterized.
The digital archiving has great advantages compared to the standard 35-mm X-ray cinefilm documentation. The data are immediately available and quantitative coronary angiography possible. In addition the technical progress is enhancing the availability of data. The loss of films is nearly eliminated, as only copies of the digital archive data are delivered. In addition a big advantage concerning pollution is present, when CD Rs are used. We report about the damage of CD Rs after 89, 162, 181 and 252 days when they were stored in polypropylene material containing envelopes. The damaged CD Rs all belonged to the provider Verbatim, whereas CD Rs of the provider Rank Xerox or Kodak were never damaged. In contrary to the Verbatim company, Rank Xerox gave written confirmation for 10-year storage and a written confirmation, that the storage in the polypropylene envelopes is possible. Mechanical, thermal damage and damage by humidity have to be discussed as well as chemical interactions of the CD Rs surface with the polypropylene material. As the digital storage for X-ray images has to be provided for 10 years in Germany, it is concluded, that the storage in polypropylene envelopes has to be avoided, when a written confirmation by the company is not given. These observations should stimulate to better control and analyze the real storage availabilities of digital data and provide in the future other media than CD R for long-term archiving.
Proper prefetching of relevant prior examinations from a picture archiving and communication system (PACS) archive, when a patient is scheduled for a new imaging study, and sending the historic images to the display station where the new examination is expected to be routed and subsequently read out, can greatly facilitate interpretation and review, as well as enhance radiology departmental workflow and PACS performance. In practice, it has proven extremely difficult to implement an automatic prefetch as successful as the experienced fileroom clerk. An algorithm based on defined metagroup categories for examination type mnemonics has been designed and implemented as one possible solution to the prefetch problem. The metagroups such as gastrointestinal (GI) tract, abdomen, chest, etc, can represent, in a small number of categories, the several hundreds of examination types performed by a typical radiology department. These metagroups can be defined in a table of examination mnemonics that maps a particular mnemonic to a metagroup or groups, and vice versa. This table is used to effect the prefetch rules of relevance. A given examination may relate to several prefetch categories, and preferences are easily configurable for a particular site. The prefetch algorithm metatable was implemented in database structured query language (SQL) using a many-to-many fetch category strategy. Algorithm performance was measured by analyzing the appropriateness of the priors fetched based on the examination type of the current study. Fetched relevant priors, missed relevant priors, fetched priors that were not relevant to the current examination, and priors not fetched that were not relevant were used to calculate sensitivity and specificity for the prefetch method. The time required for real-time requesting of priors not previously prefetched was also measured. The sensitivity of the prefetch algorithm was determined to be 98.3% and the specificity 100%. Time required for on-demand requesting of priors was 9.5 minutes on average, although this time varied based on age of the prior examination and on the time of day and database traffic. A prefetch algorithm based on metatable examination mnemonic categories can pull the most appropriate relevant priors, reduce the number of missed relevant priors, and therefore reduce the time involved for the manual task of on-demand requests of priors. Network and database traffic can be reduced as well by decreasing the number of priors selected from the archive and subsequently transmitted to the display stations, through elimination of transactions on examinations not relevant to the current study.
In the replacement of both a radiology information system (RIS) and a picture archiving and communication system (PACS) archive, data were migrated from the prior system to the new system. We report on the process, the time and resources required, and the fidelity of data transfer. We find that for two PACS archives, both organized according to the Digital Imaging and Communications in Medicine (DICOM) information model, data may be transferred with full fidelity, but the time required for transfer is significant. Transfer from off-line backup media was found to be faster than transfer from our robotic tape library. In contrast, the RIS replacement required extensive labor to translate prior data between dissimilar information models, and some data were inevitably lost in the translation. Standards for RIS information models are needed to promote the migration of data without loss of content.
We measured the throughtput rates of individual picture archiving and communications system (PACS) subsystems including the acquisition, archive, display, and communication network as a basis of evaluation the overall throughput of our clinical PACS. The throughput rate of each PACS subsystem was measured in terms of average residence time of individual images in the subsystem. The residence time of an image in a PACS subsystem was determined by the total time the image was required to be processed within the subsystem. The overall throughput of the PACS was measured as the total residence time of an image in the various subsystems. We also measured throughputs of the PACS subsystems using three types of networks (Ethernet; fiber distributed data interface; and UltraNet, UltraNetwork Technologies, San Jose, CA), and the results were compared. Approximately 200 gigabytes of data transactions including magnetic resonance, computed tomography and computed radiography images from our PACS were analyzed. Results showed that PACS throughput was limited by three major factors: (1) low-speed data interface used in the radiologic imaging devices and archive devices; (2) competition for systems processing time among the PACS processes; and (3) network degradation caused by heavy network traffic. We concluded that PACS performance could be improved with a well-designed network architecture, a job prioritizing mechanism, and an image routing strategy. However, device-dependent low-speed data interface has limited PACS performance.