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PubMed2002

[Differential diagnosis of benign and malignant mammary lesions with special regard to the BI-RADS((R)) classification system in mammography].

Mammography is the imaging method of choice for the diagnostic workup of breast tumors in screening programs as well as in symptomatic patients. Quality assurance is one of the main prerequisites for a successful performance in both fields. Quality assurance on the technical and film processing level can be easily achieved compared to reporting and outcome monitoring on the level of the physician performing mammography. This is especially due to the lack of standards of the written reports. This article reviews the Breast Imaging Reporting and Data System (BI-RADS((R))) developed and commercialized by the American College of Radiology, contains several examples of lesion classification and discusses the significance of the BI-RADS((R)) approach.

Breast↗

PubMed2003

Feasibility of school-based spirometry screening for asthma.

To determine the feasibility and value of spirometry in school-based asthma screening, spirometry testing was coupled with parent questionnaires in a school-based asthma screening project. Children in grades five to eight of the Catholic school system in Rochester, Minn., performed spirometry with coaching and data acquisition by nurses trained for this activity. Most students completed three tests. For each student, the best test was selected for interpretation. Tests were considered technically unacceptable for screening purposes if the FEV1 was less than 85% and the curve showed evidence of cough, delayed start, poor initial effort, incomplete effort, or non-reproducibility. Students with acceptable tests and FEV1 < 85% as predicted for age, race, and BMI were classified as appropriate for referral for further evaluation of potential asthma. A sensitivity analysis was conducted using different FEV1 thresholds for referral. Children (119, 17.6% of all) with known asthma based on parent-completed questionnaire were not considered for referral. Of the remaining 557 students screened, 535 had technically acceptable tests, and 498 had normal spirometry performance. Using a threshold for referral of FEV1 < 85%, 37 children were candidates for referral for further evaluation of potential asthma. Only four (11%) of these also had questionnaire responses that made them candidates for referral. School-based spirometry screening for asthma is technically feasible but there is little overlap between those who are referral candidates based on spirometry data and those who are referral candidates based on parent-reported symptoms on screening questionnaires. Without further study, spirometry cannot be recommended for school-based asthma screening.

Adolescent↗

PubMed1978

Spirometry in healthy men: a correlation with smoking and with mild symptoms.

Symptoms, smoking history, and variates taken from the forced expiratory manoeuvre were studied in a group of 271 healthy men attending a mass radiography unit. It was found that correlation of the forced expiratory ratio (FEV1/FVC) with the presence of mild or moderate respiratory symptoms was at least as satisfactory as that of technically more complicated measurements such as MEF50 and MEF75. In asymptomatic individuals those differences associated with smoking were the same for FEV1/FVC as for MEF75. Asymptomatic abnormalities of lung function were not observed. Simple measurements such as FEV1/FVC can therefore provide as much information from a forced expiratory manoeuvre to screen for early airways obstruction as MEF50 and MEF75.

Adolescent↗

PubMed2001

Molecular genetic risk screening.

Under the impetus of the Human Genome Project, new disease-associated genes are being discovered at a rapid pace. Mutations in many of these genes are present in a high enough proportion of the general population, or of particular ethnic groups, that global or targeted population screening can be contemplated. If performed early enough, identification of these mutations by molecular genetic testing can be used not merely to diagnose disease but to predict risk of future disease, either in the individual being tested or in his or her offspring. In some cases this knowledge can be the rationale for heightened surveillance and/or preventive or therapeutic interventions. Mass screening has already commenced for cystic fibrosis mutations and has been discussed for such diverse diseases as hereditary hemochromatosis, thrombophilias, familial cancer predispositions, and pharmacogenetic risk factors. However, implementation of such programs is often impeded by the complexity of the gene mutations, by incomplete penetrance, and by thorny ethical and social issues. This chapter reviews the basic criteria to be considered before embarking on population genetic risk screening, and examines multiple disease-screening examples representing a variety of modes of inheritance and technical challenges.

Cystic Fibrosis↗

PubMed1993

Use of digital mammography in needle localization procedures.

OBJECTIVE: With digital technology, images can be displayed rapidly and manipulated. This study was undertaken to assess the duration and accuracy of needle localizations performed with digital vs film-screen technology. These two technologies also were compared with respect to radiation doses and ability to image a standard phantom. SUBJECTS AND METHODS: A prototype digital mammographic system with both a 512 x 512 matrix and a 1024 x 1024 matrix was evaluated by using the American College of Radiology mammography accreditation phantom, and these results were compared with testing done on commercially available, dedicated, analog mammography equipment. Duration, accuracy of needle placement, and number of exposures needed to perform localization were recorded for 157 consecutive needle localizations done with digital technology, and these results were compared with data collected from 103 needle localizations done with film-screen technology. Another 33 localizations attempted with digital imaging were aborted because of technical factors. Average glandular doses were calculated for those women who had a compressed breast thickness of 4-5 cm. RESULTS: The time to complete needle localization was reduced by almost 50%, from 20 to 11 min, when digital technology was used. Because of the small (5 x 5 cm) field of view of the digital system, an additional mammogram obtained at the onset of the procedure was found to be helpful in localization, but otherwise the number of images was the same regardless of imaging receptor. Mean glandular dose was reduced by about 50% with digital imaging from 0.219 to 0.120 cGy. In those 17% (33/190) of needle localizations that could not be completed with digital imaging, failure was due to a variety of factors. Despite improved detectability of fibrils, specks, and masses on digital images, digital systems did not show some fine calcifications or soft-tissue masses during needle localizations. Difficulty in imaging lesions near the chest wall or in the axilla and the small field of view also caused procedures attempted with digital imaging to be aborted and completed with film-screen systems. CONCLUSION: The time to complete needle localization was reduced by 50%, with a similar reduction in patients' radiation dose, when digital mammography was used. These findings should be applicable to stereotaxic procedures done with digital mammography. Factors limiting the use of digital mammography equipment included inability to image some fine calcifications and some masses, difficulty in imaging near the chest wall and in the axilla, and a small field of view.

Breast Neoplasms↗

PubMed1986

[Screening for congenital hypothyroidism with an immunoradiometric assay (IRMA) for thyroid stimulating hormone].

A commercial immunoradiometric assay (IRMA) for thyroid stimulating hormone (TSH) was modified to be used with dried blood on filter paper of our neonatal screening programme. Sensitivity and precision were as good as with the conventional radioimmunoassay (RIA), but the IRMA was faster. In addition the IRMA was extremely cheap, because all kit reagents could be prediluted 1:4. Our screening procedure for congenital hypothyroidism now combines a determination of TSH with the IRMA technic and a determination of free thyroxin (FT4) by radioimmunoassay. The kit for FT4 can be diluted 1:3, as described earlier. The combination of TSH-IRMA und FT4-RIA to our knowledge is not only much faster but also considerably cheaper than measuring one parameter with consecutive retesting of suspicious samples, which is the procedure in some countries. As the combination gives two independent results it is also of greater clinical value than measuring TSH in dublicates, which is still officially recommended in the Federal Republic of Germany.

Antibodies, Monoclonal↗

PubMed1985

Cervicography: a preliminary report.

Cervicography is a photographic method to document abnormal cervical lesions. Screening for abnormal cervical lesions, one of the seven proposed purposes for cervicography, was investigated in this study. We evaluated 578 cervigrams obtained from patients with normal cervical cytologic tests. The evaluated cervigrams were placed in one of four categories. Seventy-nine (13.7%) of the patients had normal cervigrams; in 152 (26.4%) the result was unsatisfactory; in 159 (27.5%) the cervigram was technically defective; and in 188 (32.5%) the result was suspicious. One hundred one of the patients with suspicious cervigrams had colposcopic evaluations. In 69 patients colposcopically directed biopsies were done; 14 patients had koilocytotic atypia, seven had grade 1 cervical intraepithelial neoplasia, three had grade 2 cervical intraepithelial neoplasia, and one patient had an invasive cervical carcinoma. Although cervicography has not been proved to be cost effective, it is a method worthy of further evaluation.

Biopsy↗

PubMed1996

Screening for colorectal cancer by immunochemical fecal occult blood testing.

Screening for colorectal cancer using the conventional Hemoccult test has been shown to reduce mortality associated with cancer by 33% through a randomized controlled trial. However, the magnitude of effectiveness is small in terms of cost-effectiveness. The recently developed immunochemical fecal occult blood test (IFOBT) provides a potential replacement for the Hemoccult test as a screening test, due to its superior performance characteristics such as higher sensitivity shown in preliminary studies and the fact that it does not require any dietary restriction. The IFOBT method is reviewed, especially in relation to its specificity. In known colorectal cancer subjects, IFOBTs have shown both higher sensitivity and specificity than the Hemoccult test. Similarly, IFOBT has demonstrated a higher sensitivity than Hemoccult for colorectal cancer in an asymptomatic population. A nationwide screening program in Japan has demonstrated the feasibility of this approach for large population screening. However, the positivity rate varied according to the conditions at each screening facility. Therefore, technical factors that influence the positivity rate of IFOBTs in the screening program are discussed. Case-control studies have strongly suggested that screening using IFOBT would reduce mortality from colorectal cancer by 60% or more. Several observational studies have provided support for this estimate. The feasibility and effectiveness of population-based screening by IFOBT are discussed.

Antibodies↗

PubMed2006

How to find future ecstasy-users: targeted and snowball sampling in an ethically sensitive context.

This article documents the design and the sampling procedures of a prospective longitudinal multidisciplinary study on the neurotoxicity of ecstasy (MDMA): the Netherlands XTC Toxicity Study (NeXT). Targeted and snowball sampling was used to recruit 188 respondents who were ecstasy-naive at baseline. All respondents completed baseline questionnaires and underwent medical and neuropsychological examinations. At the end of a 11- to 26- month follow-up period in which they completed four additional questionnaires, 160 respondents remained (85.1%). A total of 65 participants (40.6%) took ecstasy for the first time during the follow-up period. This paper discusses the ethical dilemmas inherent in a study of this type and the specific problems and solutions that emerged in the sampling. The sampling was tightly constrained by our need to locate respondents who were potential future ecstasy users while also meeting strict medical and technical criteria. The 'intention to use' criterion proved to be a clear-cut inclusion rule that was practical to apply in the fieldwork.

Adolescent↗

PubMed1998

Molecular genetic methods: principles and feasibility in transfusion medicine.

The scale of the application of molecular biological techniques to modern medicine and research in the biological sciences is vast, and in many instances has captured widespread public appeal. The intention of this review is to summarise the impact of molecular techniques on Transfusion Medicine ranging from diagnostic testing (platelet, granulocyte and red cell genotyping; microbiological testing), stable gene integration into haematopoeitic stem cells (gene therapy), production of blood products in transgenic animals and cell lines, and the inhibition of gene expression using synthetic antisense oligodeoxynucleotides. All of these techniques involve the manipulation of genes, be it from the relatively simple examination of different alleles to the technically demanding ability to express mammalian genes in culture and other animals.

Animals↗

PubMed2001

MR imaging of the breast for the detection, diagnosis, and staging of breast cancer.

With the introduction of contrast agents, advances in surface coil technology, and development of new imaging protocols, contrast agent-enhanced magnetic resonance (MR) imaging has emerged as a promising modality for detection, diagnosis, and staging of breast cancer. The reported sensitivity of MR imaging for the visualization of invasive cancer has approached 100%. There are many examples in the literature of MR imaging--demonstrated mammographically, sonographically, and clinically occult breast cancer. Often, breast cancer detected on MR images has resulted in a change in patient care. Despite these results, there are many unresolved issues, including no defined standard technique for contrast-enhanced breast MR imaging, no standard interpretation criteria for evaluating such studies, no consensus on what constitutes clinically important enhancement, and no clearly defined clinical indications for the use of MR imaging. Furthermore, this technology remains costly, and issues of cost-effectiveness and cost competition from percutaneous biopsy have yet to be fully addressed. These factors along with the lack of commercially available MR imaging--guided localization and biopsy systems have slowed the transfer of this imaging technology from research centers to clinical breast imaging practices. Technical requirements, potential clinical applications, and potential pitfalls and limitations of contrast-enhanced MR imaging as a method to help detect, diagnose, and stage breast cancer will be described.

Academic Medical Centers↗

PubMed2003

Is screening with digital imaging using one retinal view adequate?

PURPOSE: To compare the detection of diabetic retinopathy from digital images with slit-lamp biomicroscopy, and to determine whether British Diabetic Association (BDA) screening criteria are attained (>80% sensitivity, >95% specificity, &<5% technical failure). METHODS: Diabetics referred for screening were studied in a prospective fashion. A single 45 degrees fundus image was obtained using the nonmydriatic digital camera. Each patient subsequently underwent slit-lamp biomicroscopy and diabetic retinopathy grading by a consultant ophthalmologist. Diabetic retinopathy and maculopathy was graded according to the Early Treatment of Diabetic Retinopathy Study. RESULTS: A total of 145 patients (288 eyes) were identified for screening. Of these, 26% of eyes had diabetic retinopathy, and eight eyes (3%) had sight-threatening diabetic retinopathy requiring treatment. The sensitivity for detection of any diabetic retinopathy was 38% and the specificity 95%. There was a 4% technical failure rate. There were 42/288 false negatives and 10/288 false positives. Of the 42 false negatives, 18 represented diabetic maculopathy, 20 represented peripheral diabetic retinopathy and four eyes had both macular and peripheral changes. Three eyes in the false-negative group (1% of total eyes) had sight-threatening retinopathy. There was good concordance between the two consultants (79% agreement on slit-lamp biomicroscopy and 84% on digital image interpretation). CONCLUSION: The specificity value and technical failure rate compare favourably with BDA guidelines. The low sensitivity for detection of any retinopathy reflects failure to detect minimal maculopathy and retinopathy outside the 45 degrees image. This could be improved by an additional nasal image and careful evaluation of macular images with a low threshold for slit-lamp biomicroscopy if image quality is poor.

Diabetic Retinopathy↗

PubMed2006

Lab on a CD.

In this paper, centrifuge-based microfluidic platforms are reviewed and compared with other popular microfluidic propulsion methods. The underlying physical principles of centrifugal pumping in microfluidic systems are presented and the various centrifuge fluidic functions, such as valving, decanting, calibration, mixing, metering, heating, sample splitting, and separation, are introduced. Those fluidic functions have been combined with analytical measurement techniques, such as optical imaging, absorbance, and fluorescence spectroscopy and mass spectrometry, to make the centrifugal platform a powerful solution for medical and clinical diagnostics and high throughput screening (HTS) in drug discovery. Applications of a compact disc (CD)-based centrifuge platform analyzed in this review include two-point calibration of an optode-based ion sensor, an automated immunoassay platform, multiple parallel screening assays, and cellular-based assays. The use of modified commercial CD drives for high-resolution optical imaging is discussed as well. From a broader perspective, we compare technical barriers involved in applying microfluidics for sensing and diagnostic use and applying such techniques to HTS. The latter poses less challenges and explains why HTS products based on a CD fluidic platform are already commercially available, whereas we might have to wait longer to see commercial CD-based diagnostics.

Biological Assay↗

PubMed1993

Bone mass measurement: how, where, when and why?

Low bone mass, by far the major causal factor in osteoporotic fractures, cannot be predicted from the clinical evaluation of risk factors for osteoporosis. Measurement of bone mass is commonly achieved by using dual-energy X-ray absorptiometry (DXA), which has replaced dual-photon absorptiometry (DPA); single-energy X-ray absorptiometry (SXA), which is likely to replace I-125 single-photon absorptiometry; and by using quantitative computed tomography (QCT). Measurement of ultrasound speed and attenuation across the calcaneum is another promising method still under investigation. Each method may have some advantage or disadvantage relating to practical aspects (cost, scanning time, availability) and technical aspects (radiation dose, accuracy, precision). Several clinical situations have been identified in which measurement of bone mass will be useful, including women after the menopause to select those who should receive bone-sparing agents, and patients with x-ray vertebral deformity to confirm the diagnosis of osteoporosis. DXA allows measurement of bone mass at different skeletal sites, including the lumbar spine (by anteroposterior and lateral view), the hip, the forearm, and the total skeleton. The choice of the site to be screened will often be dictated by clinical considerations such as age and associated osteoarthritis, but, in theory, should be oriented by the ability of bone mass measurement at each site to predict osteoporotic fractures. Several prospective studies have shown that a decrease of 1 standard deviation of bone mass is associated with a 1.5- to 3-fold increase of the relative risk of fracture. Measuring any site is probably equally predictive of the risk of all osteoporotic fractures, while measurement of the hip appears to be a better predictor of the risk of hip fracture.

Absorptiometry, Photon↗

PubMed2004

Clinical utility of rapid prescreening magnetic resonance angiography of peripheral vascular disease prior to cardiac catheterization.

PURPOSE: The presence of peripheral vascular disease, in particular iliofemoral disease, is responsible in part for vascular complications from femoral artery cannulation. We investigated whether prescreening for vascular obstructions with magnetic resonance angiography (MRA) in high-risk patients with peripheral vascular disease (PVD) would provide useful information to angiographers seeking to improve the safety and efficiency of femoral artery access at cardiac catheterization. METHODS: Twelve consecutive patients with known or suspected PVD underwent contrast-enhanced, aorto-iliofemoral MRA using a real-time BolusTrak technique. Contrast-to-noise ratios for each patient were calculated. The cardiac angiographer reviewed the MRA prior to catheterization and selected an access site. The patients' subsequent clinical course was evaluated, and a postprocedure questionnaire was completed by the angiographer to define the value of the prescreening MRA. RESULTS: No significant vascular complications occurred in these patients as defined by failure of initially chosen access site, arterial dissection, limb ischemia, pseudoaneurysm formation, hemorrhage (including retroperitoneal hematoma), or need for blood transfusion or emergency vascular surgical repair. Statistical frequency analysis of the responses in the postprocedure questionnaire demonstrated that the MR data were clinically valuable in (1) influencing the initial choice of access site; (2) influencing technical alterations to the standard access; and, (3) enhancing confidence in the selection of access site. CONCLUSIONS: MRA prescreening in patients with PVD is an effective, novel adjunct to cardiac catheterization in selected patients that improves physician confidence and influences technical choices during coronary angiography from the femoral artery approach.

Adult↗

PubMed1987

[Evaluation of the detection of phenylketonuria and hypothyroidism at the Lille Regional Center].

During the past 20 years, neonatal screening for metabolic diseases has been developed and implemented in the Nord-Pas de Calais region. The regional centre (established in 1972) has screened more than 1,000,000 babies for phenylketonuria (PKU) and more than 700,000 for congenital hypothyroidism (CH). Ninety-two PKU and 182 CH patients were discovered and treated. The recent introduction of a computerised system for the clerical works in the centre has allowed a systematic survey of some parameters linked to the screening practices: collection, handling and follow-up of samples. The analysis of these parameters showed that 50% of samples were collected on the 5th day of life but 35% were collected after that date, and that 4.7% of specimen reached the laboratory 10 days or more after the day of collection. These delays can introduce a significant delay in the final diagnosis of affected children. The average age at which the diagnosis was suspected was 12.2 days in PKU and 20.6 days in CH. The difference was not only explained by the technical delay for TSH measurement but also by a later date of sampling. This observation suggests that, if blood collection was performed before nursery discharge, there were some pathologic factors justifying a later discharge. Of the control specimen (second test) which have been requested, 16% were not received; this represents a high risk of missing a case.

Congenital Hypothyroidism↗

PubMed1997

Spiral noncontrast CT versus combined plain radiography and renal US after extracorporeal shock wave lithotripsy: cost-identification analysis.

PURPOSE: To investigate the costs of spiral computed tomography (CT) versus those of combined plain radiography and renal ultrasound (US) in screening for postprocedural complications after extracorporeal shock wave lithotripsy (ESWL). MATERIALS AND METHODS: Twenty-five adult patients who had undergone ESWL were prospectively examined with spiral CT, renal US, and plain abdominal radiography. Each examination was timed, and direct technical costs were calculated by using a procedural-based cost-accounting system. The combined cost of US and plain radiography was compared with the cost of spiral CT. RESULTS: The average time for spiral CT was 15.3 minutes compared with 37.2 minutes for combined US and plain radiography. The direct technical cost of spiral CT was $36.86 compared with $57.60 for combined US and plain radiography. Average examination times were varied to assess the effect on overall costs. Within reasonable time ranges, combined US and plain radiography cannot be cost equivalent to spiral CT. CONCLUSION: Spiral CT is faster and is associated with less direct technical cost than combined US and plain radiography when used to examine patients after ESWL, given the dependence of this model on time of examination. Further studies are needed to assess the relative accuracy of these alternative approaches.

Adult↗

PubMed1989

[A fermenter dialysis cultivation technic for encapsulated pathogenic bacteria. II. Group B streptococci].

For mass cultivation of group B streptococci (B-III and B-variant streptococci), a fermenter dialysis culture technique is described and compared to conventional shaking culture and fermenter batch culture techniques. The influence of two kinds of cultivation media on the bacterial yield is demonstrated. The growth rate of the bacteria and the yield of the microbes is higher in modified POPE medium than that observed with Nährbouillon I. The type-specific polysaccharide of B-III-streptococci prepared by phenol-water extraction followed by gel-chromatography can be used as a screening antigen for the production of monoclonal antibodies against B-III-streptococci.

Antigens, Bacterial↗