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At least 1,621 records · Page 90Linked to original sources
PubMed2003

Computed tomography of acute pulmonary embolism.

Pulmonary embolism (PE) is a common condition in which diagnostic and therapeutic delays contribute to substantial morbidity and mortality. Advances in spiral computed tomography (CT) scanner technology over the past 10 years have been paralleled by progressive improvement in the ability to identify and accurately evaluate the pulmonary arteries for acute PE using CT pulmonary angiography (CTPA). Preliminary studies indicate multi-detector CT (MDCT) scanners offer improved accuracy for distal segmental and subsegmental PE. The ability to directly visualize emboli using CTPA has led to its widespread implementation. Published studies using optimal techniques have found sensitivity and specificity of approximately 90%. Clinical signs and symptoms are nonspecific. Only 20% to 30% of those patients evaluated for acute PE are found to harbor emboli. Previous imaging algorithms offered limited diagnostic value for the remaining 70% to 80% of patients who proved not to have PE. It has been shown that spiral CT identifies an alternate diagnosis in approximately 70% of these patients, which, along with its rapid and widespread availability, largely accounts for its popularity with referring clinicians. It is noted that meta-analysis studies of the existing data regarding spiral CT in acute PE have shown deficiencies in study designs, indicating that further research is required. However, at this time, spiral CT is being widely employed in the diagnostic work-up of patients with suspected acute PE. This review will discuss the use of spiral CT for acute PE, including scan acquisition parameters, radiation dose, diagnostic findings, interpretive pitfalls and the role of leg vein studies.

Acute Disease↗
PubMed2001

Erectile dysfunction in uremic dialysis patients: diagnostic evaluation in the sildenafil era.

The two words that mean sexual dysfunction, impotence and erectile dysfunction (ED), express two different concepts. Impotence is a general male sexual dysfunction that includes libidinal, orgasmic, and ejaculatory dysfunction. ED is the inability to achieve or maintain an erection sufficient to allow satisfactory sexual intercourse and is part of the general male sexual dysfunction termed impotence that includes libidinal, orgasmic, and ejaculatory dysfunction. Uremic men of different ages report a variety of sexual problems, including sexual hormonal pattern alterations, reduction in or loss of libido, infertility, and impotence, conditioning their well-being status. In evaluating and treating sexual dysfunction, a nephrologist must consider factors involved in its pathogenesis, such as hypothalamic-pituitary-gonadal axis alterations, psychological problems related to chronic disease, secondary hyperparathyroidism, anemia, autonomic neuropathy, derangements in arterial supply or venous outflow, and the normal structure of cavernous body smooth muscle cells. The introduction of sildenafil to treat impotent patients has completely changed the approach to evaluating these subjects because this drug is considered an effective well-tolerated treatment for men with ED. In the past, we proposed an algorithm that gave the opportunity to explore the previously mentioned factors using such instrumental interventions as the nocturnal penile tumescence test, penile echo color Doppler, nervous conduction velocity, and cavernous body biopsy, addressed to prescribe needed surgical or medical interventions. The complexity of the proposed algorithm requires many diagnostic procedures and much time and economic resources to localize the pathological lesions responsible for ED. Because of the new oral drug sildenafil, we propose a new algorithm to test the possibility of obtaining an erection and classify patients as responders or nonresponders to the sildenafil test.

Bromocriptine↗
PubMed2004

Computer-aided diagnosis of mammographic microcalcification clusters.

Computer-aided diagnosis techniques in medical imaging are developed for the automated differentiation between benign and malignant lesions and go beyond computer-aided detection by providing cancer likelihood for a detected lesion given image and/or patient characteristics. The goal of this study was the development and evaluation of a computer-aided detection and diagnosis algorithm for mammographic calcification clusters. The emphasis was on the diagnostic component, although the algorithm included automated detection, segmentation, and classification steps based on wavelet filters and artificial neural networks. Classification features were selected primarily from descriptors of the morphology of the individual calcifications and the distribution of the cluster. Thirteen such descriptors were selected and, combined with patient's age, were given as inputs to the network. The features were ranked and evaluated for the classification of 100 high-resolution, digitized mammograms containing biopsy-proven, benign and malignant calcification clusters. The classification performance of the algorithm reached a 100% sensitivity for a specificity of 85% (receiver operating characteristic area index Az = 0.98 +/- 0.01). Tests of the algorithm under various conditions showed that the selected features were robust morphological and distributional descriptors, relatively insensitive to segmentation and detection errors such as false positive signals. The algorithm could exceed the performance of a similar visual analysis system that was used as basis for development and, combined with a simple image standardization process, could be applied to images from different imaging systems and film digitizers with similar sensitivity and specificity rates.

Algorithms↗
PubMed2003

Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative.

OBJECTIVE: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy in order to allow readers to assess the potential for bias in a study and to evaluate the generalisability of its results. METHODS: The Standards for Reporting of Diagnostic Accuracy (STARD) steering committee searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies and extracted potential items into an extensive list. Researchers, editors, and members of professional organisations shortened this list during a 2-day consensus meeting with the goal of developing a checklist and a generic flow diagram for studies of diagnostic accuracy. RESULTS: The search for published guidelines about diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. At the consensus meeting, participants shortened the list to a 25-item checklist, by using evidence whenever available. A prototype of a flow diagram provides information about the method of recruitment of patients, the order of test execution and the numbers of patients undergoing the test under evaluation, the reference standard, or both. CONCLUSIONS: Evaluation of research depends on complete and accurate reporting. If medical journals adopt the checklist and the flow diagram, the quality of reporting of studies of diagnostic accuracy should improve to the advantage of clinicians, researchers, reviewers, journals, and the public.

Algorithms↗
PubMed2007

Pancreatic cancer imaging: the new role of endoscopic ultrasound.

Pancreatic cancer is the most deadly of all gastrointestinal malignancies and has a very poor prognosis. Unfortunately, most patients present late in the course of their disease and, at the time of diagnosis, only 10 to 25% of patients will be eligible for potentially curative resection. Efforts must be oriented towards an early diagnosis and towards reliably identifying patients who can really benefit from major surgery. A suspected pancreatic tumor can be a difficult challenge for the clinician. In the last ten years, we have witnessed notable technological improvements in radiological and nuclear imaging. Taking this into account, we will try to delineate the new role of endoscopic ultrasound (EUS) in pancreatic tumor imaging and to place EUS in a shareable diagnostic and staging algorithm. To date, the most accurate imaging techniques for pancreatic neoplasms remain contrast-enhanced computed tomography and EUS. EUS has the highest accuracy in detecting small lesions, in assessing tumor size and lymph node involvement, but helical CT must still be the first choice in patients with a suspected pancreatic tumor. However, after this first step, there is a place for EUS as a second diagnostic level in several cases: negative results on CT scan and persistent strong clinical suspicion of pancreatic cancer, doubtful results on CT scans or the need for cytohistological confirmation. In the near future, there will be great opportunities for the development of diagnostic and therapeutic EUS and pancreatic cancer could be the best testing ground.

Biopsy, Fine-Needle↗
PubMed2006

Individualized selection of pacing algorithms for the prevention of recurrent atrial fibrillation: Results from the VIP registry.

OBJECTIVES: The VIP registry investigated the efficacy of preventive pacing algorithm selection in reducing atrial fibrillation (AF) burden. BACKGROUND: There are few data identifying which patients might benefit most from which preventive pacing algorithms. METHODS: Patients, with at least one documented AF episode and a conventional antibradycardia indication for pacemaker therapy, were enrolled. They received pacemakers with AF diagnostics and four preventive algorithms (Selection and PreventAF series, Vitatron). A 3-month Diagnostic Phase with conventional pacing identified a Substrate Group (>70% of AF episodes with <2 premature atrial contractions [PACs] before AF onset) and a Trigger Group (< or =70% of AF episodes with <2 PACs before AF onset). This was followed by a 3-month Therapeutic Phase where in the Trigger Group algorithms were enabled aimed at avoiding or preventing a PAC and in the Substrate Group continuous atrial overdrive pacing was enabled. RESULTS: One hundred and twenty-six patients were evaluated. In the Trigger Group (n = 73), there was a statistically significant 28% improvement in AF burden (median AF burden: 2.06 hours/day, Diagnostic Phase vs 1.49 hours/day, Therapy Phase; P = 0.03304 signed-rank test), and reduced PAC activity. There was no significant improvement in AF burden in the Substrate Group (median AF burden: 1.82 hours/day, Diagnostic Phase vs 2.38 hours/day, Therapy Phase; P = 0.12095 signed-rank test), and little change in PAC activity. CONCLUSIONS: We identified a subgroup of patients for whom the selection of appropriate pacing algorithms, based on individual diagnostic data, translated into a reduced AF burden. Trigger AF patients were more likely responders to preventive pacing algorithms as a result of PAC suppression.

Aged↗
PubMed2004

Lupus-like disease with anticardiolipin antibodies and lupus anticoagulant as a cause for atypical Eaton-Lambert syndrome and peripheral nerve disease: a case report.

In the practice of neurology, the type of clinical involvement suggests the site of the lesion and the mechanism beneath. Sometimes, the symptoms can be delusive, turning the diagnostic approach to a wrong path and raising the necessity of an algorithm considering the less probable entities. Dysimmunity as mechanism of neurological disease involving both the neuromuscular junction and peripheral nerves is frequently insidious and difficult to suspect on clinical basis alone. We report the case of a 67-year-old male with atypical Eaton-Lambert syndrome and mononeuropathy probably in relation with lupus-like entity. The patient has also high titers of anticardiolipin antibodies and lupus anticoagulant. We are considering the diagnostic algorithm before an isolated and atypical neurological presentation and reviewing the main neurological manifestations in lupus-like and autoimmune systemic disease. We raise the difficulty to classify an inflammatory connective tissue disease in the absence of other pathologic features than autoantibodies and isolated neurological symptoms and discussing the main therapeutic issues.

Aged↗
PubMed2001

Comparison of image reconstruction algorithms in myocardial perfusion scintigraphy.

The purpose of this study was to compare the clinical utility of two image reconstruction algorithms in myocardial perfusion SPECT (single-photon emission computed tomography): filtered back-projection (FBP) and ordered subset expectation maximization (OSEM). A rest/stress one-day protocol with 99mTc-MIBI or tetrofosmin was performed on 102 consecutive patients who underwent coronary angiography. After SPECT data acquisition, images were reconstructed with FBP and OSEM algorithms. We assessed diagnostic performance (sensitivity, specificity and accuracy) in detecting coronary artery stenosis and evaluated regional tracer uptake with a 4-point scoring system. Although there were no significant differences in diagnostic performance between FBP and OSEM reconstruction, the OSEM method yielded higher uptake in the RCA area than the FBP method by reducing the count-loss artifact due to hepatic uptake of the tracers. In addition, regional uptake in the LCX area was significantly lower in the OSEM image than in the FBP image; this phenomenon was observed mainly in patients with coronary stenosis and/or infarction in the LCX territory. In conclusion, OSEM and FBP offered comparable diagnostic performance in stress myocardial perfusion SPECT. The OSEM method contributed to reduction of the count-loss artifact in inferior and posterior walls and to easy recognition of hypoperfusion in the LCX area.

Algorithms↗
PubMed1981

Selective management of penetrating neck trauma. Cost implications.

Many authors advocate mandatory surgical exploration for all patients with penetrating neck trauma, while other maintain that with careful diagnostic evaluation some patients safely can be spared an operation. From our hospitals, 65 cases of penetrating neck trauma were reviewed, 27 of which showed no mortality without operation. Surgical exploration of the neck showing no injury added $1,930 to the cost of hospitalization. Review of the surgical literature discloses that mortalities reported by authors advocating selective and mandatory exploration are similar. The incidence of missed significant injury is low among patients observed selectively. A management algorithm for the diagnostic evaluation and treatment of patients with penetrating neck trauma is advocated. All stable patients should undergo four-vessel angiography. Studies of the cervical esophagus may be performed. Patients with entirely normal diagnostic evaluations may be observed safely, sparing unnecesary operation.

Adolescent↗
PubMed1994

Orbital emphysema. Staging and acute management.

BACKGROUND: Orbital emphysema is usually a benign, transient phenomenon. Rarely, the intraorbital air mass can cause central retinal artery occlusion. Because of the potential for severe visual loss, the rapid diagnosis and management of this condition are essential. Currently, there is no standard protocol for the treatment and management of severe orbital emphysema. To develop a management algorithm, the authors reviewed the records of eight patients with orbital emphysema, in addition to nine other reported patients with ocular dysfunction. METHODS: Retrospective review of patients with orbital emphysema who have proptosis, diplopia, or loss of vision. RESULTS: Orbital emphysema is associated with small orbital fractures. The location of the intraorbital air mass usually correlates with the fracture location. A four-stage classification system of orbital emphysema is developed. This staging system is helpful in constructing an acute diagnostic and management algorithm for orbital emphysema. CONCLUSION: Understanding the pathophysiology of orbital emphysema is important in developing a rational approach to manage this potentially sight-threatening condition. Treatment using a needle-coupled open syringe filled with saline allows direct monitoring of the air mass during decompression.

Adult↗
PubMed2024

A corpus of GA4GH phenopackets: Case-level phenotyping for genomic diagnostics and discovery.

The Global Alliance for Genomics and Health (GA4GH) Phenopacket Schema was released in 2022 and approved by ISO as a standard for sharing clinical and genomic information about an individual, including phenotypic descriptions, numerical measurements, genetic information, diagnoses, and treatments. A phenopacket can be used as an input file for software that supports phenotype-driven genomic diagnostics and for algorithms that facilitate patient classification and stratification for identifying new diseases and treatments. There has been a great need for a collection of phenopackets to test software pipelines and algorithms. Here, we present Phenopacket Store. Phenopacket Store v.0.1.19 includes 6,668 phenopackets representing 475 Mendelian and chromosomal diseases associated with 423 genes and 3,834 unique pathogenic alleles curated from 959 different publications. This represents the first large-scale collection of case-level, standardized phenotypic information derived from case reports in the literature with detailed descriptions of the clinical data and will be useful for many purposes, including the development and testing of software for prioritizing genes and diseases in diagnostic genomics, machine learning analysis of clinical phenotype data, patient stratification, and genotype-phenotype correlations. This corpus also provides best-practice examples for curating literature-derived data using the GA4GH Phenopacket Schema.

Humans↗
PubMed1989

The role of imaging in the diagnostic evaluation of impotence.

This article serves to highlight the recent advances that have been made in the workup and differential diagnosis of erectile dysfunction, focusing particularly on the role of imaging in this diagnostic assessment. Intracavernosal injection of vasoactive agents, duplex sonography with pulsed Doppler analysis, penile arteriography, and dynamic infusion pharmacocavernosometry/cavernosography are among the techniques discussed. With the development and availability of nonprosthetic treatment options, identification of the specific underlying cause of a patient's impotence (as determined by these methods) allows the formulation and institution of a therapeutic plan based on the patient's underlying pathophysiology and appropriate for the individual's case. On the basis of our experience, we present a practical and cost-effective algorithm for the diagnostic evaluation of the impotent patient.

Angiography↗
PubMed2005

Pulmonary nodule.

A pulmonary nodule is a frequent and often incidental finding, and still represents a diagnostic challenge for radiologists. Although most solitary nodules are related to benign disease, some represent stage I lung cancers. and need to be distinguished from benign nodules in a cost-effective manner. The aim of diagnostic assessment should be to allow early treatment of small malignant nodules but avoid unnecessary biopsy or surgery, with their attendant risks, in patients with benign disease. The advent of Multislice Computed Tomography (MSCT) technology has sparked new interest in the non-invasive assessment of pulmonary nodules. Thanks to its ability to scan the whole thoracic volume with thinner collimations, this technology allows a more accurate identification and characterisation of pulmonary nodules, as well as the determination of perfusion patterns and growth rates. In this paper we present an algorithm for the diagnostic workup of incidentally detected small pulmonary nodules in subjects without known malignancy.

Humans↗
PubMed2003

[The role of hormone analysis in the nosologic diagnosis and in the control of treatment of congenital primary hypothyroidism].

A total of 125 children and teenagers, aged 1 to 15 (including 74 patients with primary congenital hypothyroidism--CH--and 51 healthy children), were investigated in the city of Moscow for the purpose of elaborating new approaches towards the differentiated diagnostics of CH and of optimizing the assessment of the adequacy of its substitutive hormonal therapy (SHT). The concentrations of the thyrotropic hormone (TTH), free fractions of triiodothyronine and thyroxin (cT3 and cT4), thyreoglobulin (Tg) and of thyreoid peroxidase (hard-phase test-tube method, electro-chemiluminescent reaction, i.e. magnetic microparticles, based on the streptovidin-biotin technology; ruthenium mark at the "Elecsys 1010" analyzer with reagents manufactured by "F. Hoffman--La Rosh Ltd.", Switzerland.) were determined early in the morning on the empty stomach. On the basis of the above mentioned, the thyroid reserve index (TRI = Tg/TG), integral thyroid index (ITI = [cT3 + cT4]/TTG), and the integral of peripheral conversion (IPC = cT3/cT4) were calculated. The thyroid gland (TG) was visualized by the "Acuson-128 XP" ultrasonic device, "Acuson Corp.", USA, with a linear sensor of 10 Mhz, as well as by the "Toshiba-90B" gamma-chamber, Japan, with a low-energy collimator in 24 hours after an oral intake of sodium iodide marked by the iodine 123-isotope with an activity of 50 Mbc and after the cessation of SHT 3 to 5 weeks before. The complex diagnosis revealed 8 variations of primary CH; aplasia and TG dystopia and defects of the synthesis of the sodium-iodine symporter or Tg-concentration were found to belong to the most severe disease types according to hormonal parameters. As for Tg, in 52% of cases it was normal, undeterminable--23% and higher--25%. A simultaneously implemented ultrasonic scanning (USS) ensured a final diagnosis in subgroups, respectively, in all cases, in 25% and in 75% of patients. On the whole, after the two diagnostic stages (Tg + USS/ITR), the indications for isotope scanning left only for 23% of CH patients, i.e. a) if the Tg values could not be determined because the organ was not located in its typical place (17%); or b) if the Tg level was higher or if there was a goiter at the TG normal volume (6%). An in-depth hormonal analysis showed that, should CHT be monitored less than once in three months, it failed to secure a total compensation of the disease in above one third of CH children (39%). Therefore, a three-stage algorithm of nosological diagnostics is recommended for primary CH; it should comprise the determination of Tg level, and USS (for all patients) as well as TG scanning (according to rare indications). The result point at the necessity of hormonal monitoring of CH children and teenagers at least one in 2-3 months. The objectivity degree of CHT goes up as a number of estimated indices, i.e. ITI and IPC, are used alongside with absolute hormonal values.

Adolescent↗
PubMedDate not supplied

[Development and evaluation of screening algorithms for sexually transmitted diseases in pregnant women at Libreville, Gabon].

The struggle against sexually transmitted diseases (STD) constitutes a priority of public health in developing countries: STD cause complications, particularly in pregnant women, and facilitate the transmission of HIV. One of the strategies in the struggle against STD is the diagnosis and the early treatment of these infections. The STD, and in particular infections of Neisseria gonorrhea and Chlamydia trachomatis, are difficult to diagnose in women without complementary analyses, which primary health care may not be able to supply. Health care provided to patients could be standardized and improved by considering the signs and symptoms. We studied the prevalence and risk factors of STD among 192 pregnant women consulting the health clinic in Libreville, Gabon, in September 1993. The prevalence of STD was high (13.5% rate of cervical infection with gonorrhea or Chlamydia trachomatis). We then evaluated the different diagnostic strategies or algorithms. Regardless of the type of examination (medical interview, simple clinical examination or examination with a speculum), the use of scores integrating risk factors, the clinical signs and symptoms outperformed hierarchical algorithms. This approach was more sensitive and specific and easy to perform. Use of this method may enable more effective screening of STD and also avoid most maternal and perinatal complications.

Adolescent↗
PubMed1996

Algorithms for verbal autopsies: a validation study in Kenyan children.

The verbal autopsy (VA) questionnaire is a widely used method for collecting information on cause-specific mortality where the medical certification of deaths in childhood is incomplete. This paper discusses review by physicians and expert algorithms as approaches to ascribing cause of deaths from the VA questionnaire and proposes an alternative, data-derived approach. In this validation study, the relatives of 295 children who had died in hospital were interviewed using a VA questionnaire. The children were assigned causes of death using data-derived algorithms obtained under logistic regression and using expert algorithms. For most causes of death, the data-derived algorithms and expert algorithms yielded similar levels of diagnostic accuracy. However, a data-derived algorithm for malaria gave a sensitivity of 71% (95% Cl: 58-84%), which was significantly higher than the sensitivity of 47% obtained under an expert algorithm. The need for exploring this and other ways in which the VA technique can be improved are discussed. The implications of less-than-perfect sensitivity and specificity are explored using numerical examples. Misclassification bias should be taken into consideration when planning and evaluating epidemiological studies.

Algorithms↗
PubMed2003

Should family planning clinics provide clinical services for sexually transmitted infections? A case study from Côte d'Ivoire.

OBJECTIVES: To evaluate the quality and usefulness of integrated sexually transmitted infection (STI) care at non-governmental family planning (FP) clinics in Côte d'Ivoire. METHODS: Evaluation components included: (1) a survey measuring the prevalence of STI and the predictive value of the Ivorian vaginal discharge treatment algorithm, (2) client exit interviews, (3) direct observations of client-provider contacts, (4) the monitoring of the clinics' workload and available equipment and supplies and (5) interviews of programme managers and FP providers. RESULTS: Among 368 FP clients surveyed, the prevalence of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, B. vaginosis and Candida albicans were respectively 1.6, 5.7, 7.1, 44.8 and 5.2%. The positive predictive value of the national algorithm for the detection of cervicitis was only 6.3%, and was 17.9% among a subgroup of young, single women. Of 200 clients interviewed, 96% were satisfied with the services and 95% would return to the FP clinic if they had genital problems. In 215 observed client-provider contacts, 88% of 94 STI cases were correctly managed. Programme managers and providers reported no substantial work overload as a result of the integration of STI services. CONCLUSIONS: The prevalence of cervical infections is relatively low in this population and the Ivorian algorithm that treats all women with vaginal discharge performs poorly. Over-treatment of cervicitis can be reduced by modifying the algorithm, although improved diagnostic tools are urgently needed to detect cervicitis in this population. Continued STI case management at the FP clinics is nevertheless justified because there exists an easily identifiable group of higher risk women who need STI care; and because of the demand by a large proportion of clients, the high prevalence of vaginal pathogens, and the limited costs to the FP programme.

Adolescent↗
PubMed2005

Detection of mild emphysema by computed tomography density measurements.

PURPOSE: To assess the ability of a conventional density mask method to detect mild emphysema by high-resolution computed tomography (HRCT); to analyze factors influencing quantification of mild emphysema; and to validate a new algorithm for detection of mild emphysema. MATERIAL AND METHODS: Fifty-five healthy male smokers and 34 never-smokers, 61-62 years of age, were examined. Emphysema was evaluated visually, by the conventional density mask method, and by a new algorithm compensating for the effects of gravity and artifacts due to motion and the reconstruction algorithm. Effects of the reconstruction algorithm, slice thickness, and various threshold levels on the outcome of the density mask area were evaluated. RESULTS: Forty-nine percent of the smokers had mild emphysema. The density mask area was higher the thinner the slice irrespective of the reconstruction algorithm and threshold level. The sharp algorithm resulted in increased density mask area. The new reconstruction algorithm could discriminate between smokers with and those without mild emphysema, whereas the density mask method could not. The diagnostic ability of the new algorithm was dependent on lung level. At about 90% specificity, sensitivity was 65-100% in the apical levels, but low in the rest of the lung. CONCLUSION: The conventional density mask method is inadequate for detecting mild emphysema, while the new algorithm improves the diagnostic ability but is nevertheless still imperfect.

Absorptiometry, Photon↗