Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “diagnostic optimization”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,369 records · Page 76Linked to original sources
PubMed2002

Clinical relevance of viral dynamics and genotypes in hepatitis B virus.

Advances in molecular diagnostic technology make it possible to accurately measure viral loads and this has allowed the detailed study of viral dynamics of HIV, hepatitis C virus (HCV) and hepatitis B virus (HBV). Following antiviral therapy, there are at least two phases of viral load decay: one corresponding to clearance of free virions and a second, slower phase corresponding to eradication of infected cells. Application of mathematical models allows for the assessment of antiviral efficacy and improved design of therapeutic regimens. The clinical application of these tools should help optimize patient outcome. Another advantage of molecular diagnostics is characterization of the heterogeneity of viruses in particular patient populations under selective pressure situations. The HBV can be classified into seven major genotypes (A-G) that have mainly a geographic distribution. Recent genotypic studies have revealed the clinical and therapeutic relevance of viral genotyping in HBV infections.

Antiviral Agents↗
PubMed2004

Comparison of first void urine and urogenital swab specimens for detection of Mycoplasma genitalium and Chlamydia trachomatis by polymerase chain reaction in patients attending a sexually transmitted disease clinic.

OBJECTIVE: The objective of this study was to compare urogenital swab specimens and first void urine (FVU) specimens from male and female patients at a sexually transmitted disease clinic for the detection of Mycoplasma genitalium and Chlamydia trachomatis infections using in-house, inhibitor-controlled polymerase chain reaction (PCR). STUDY DESIGN: Urethral swabs and FVU were collected from 1856 men and 753 women who also had a cervical swab collected. A positive diagnosis of infection was made if any 1 of the specimens tested positive and were confirmed in a second PCR assay targeting independent genes. RESULTS: M. genitalium DNA and C. trachomatis DNA were detected in 126 (6.8%) and 246 (13.3%) of the male sample sets and in 51 (6.8%) and 73 (9.7%) of the female specimen sets, respectively. Using our in-house PCR and sample preparation methods, FVU was found to be the most sensitive diagnostic specimen for both pathogens, but for optimal sensitivity, it should be supplemented with a cervical specimen in women. In a small subset of female FVUs, storage at -20 degrees C led to false-negative M. genitalium PCR results in 27% of specimens found positive when a sample preparation was performed before freezing. The age-specific prevalence of M. genitalium in men was almost constant between 18 and 45 years of age in contrast to C. trachomatis infections, which were more common in younger men. CONCLUSION: Urine appeared to be a better diagnostic specimen than the urethral swab for M. genitalium and C. trachomatis detection by PCR in this cohort of sexually transmitted disease clinic attendees but should be supplemented with a cervical specimen in women.

Adolescent↗
PubMed1997

New approaches to the integrated management of early lung cancer.

We have briefly surveyed some the developments in the field of molecular diagnostics that provide a basis for cautious optimism about progress in population-based early lung cancer screening. The sound lung cancer management strategies that were formulated several decades ago failed in clinical trials because the necessary tools to implement the strategies were not yet available. Technology is beginning to emerge that makes population-based screening achievable. This same technology may be used to define a comprehensive marker panel including the most informative markers from the long list of candidate markers. Validation studies will define more clearly the strengths and limitations of new molecular diagnostics and provide leads for further research attention. The clinical community can expedite this process if these validation efforts are aggressively pursued. Parallel developments are clearly needed in refining the range of therapeutic intervention for early cancer management. The success of both diagnostic and intervention tools is interwoven in the ultimate goal of reducing lung cancer mortality. This article is an invitation to think expansively about new approaches to cancer care that integrate the fruits of our hard-learned lessons.

Humans↗
PubMed2004

Molecular diagnostics: current options.

Diagnostic medical bacteriology consists of two main components: identification and typing. Molecular biology has the potential to revolutionize the way in which diagnostic tests are delivered in order to optimize the care of infected patients, whether they are in hospital or in the community. Since the discovery of the polymerase chain reaction (PCR) in the late 1980s, an enormous amount of research has enabled the introduction of molecular tests into several areas of routine clinical microbiology. Molecular biology techniques continue to evolve rapidly, and many laboratories have been reluctant to introduce these new methods due to concerns that the technology would become outdated. In consequence, the vast majority of clinical bacteriology laboratories do not currently use any molecular diagnostics, although such technology is becoming more widespread in specialized regional laboratories, as well as in national reference laboratories. Presently, molecular biology offers a wide repertoire of techniques and permutations. This chapter is intended to explore the application of these in the diagnostic laboratory setting.

Bacteria↗
PubMed2026

Development of Electrocardiography Standards for Evaluating Myocardial Infarction and Ischemia-Reperfusion Injury in Mice.

BACKGROUND: Acute and chronic heart failure secondary to myocardial infarction (MI) and cardiac ischemia-reperfusion injury (IRI) are leading causes of death in ischemic heart disease. A mouse model is indispensable for investigating MI and IRI, and the development of reliable mouse MI and IRI models is essential for advancing research in this field. The clear early diagnostic criteria for confirming successful induction of MI and IRI in mice remain lacking. METHODS: Adult C57BL/6J background mice underwent left anterior descending coronary artery ligation to induce acute MI, or ligation followed by reperfusion to induce IRI. The success of the MI and IRI model establishment was confirmed by 2,3,5-triphenyltetrazolium chloride staining and echocardiography. Electrocardiography was used to monitor the electric activity in the mice. CONCLUSIONS: Electrocardiography demonstrated that ST-segment elevation in ECG lead II and corrected QTc interval prolongation at 30 minutes following left anterior descending ligation as 2 key early indicators of successful MI. Echocardiography analysis revealed that the magnitude of ST-segment elevation strongly correlated with the left anterior descending ligation site, where a more proximal ligation produced a greater ST-segment elevation amplitude and more severe ischemia. In IRI models, ST-segment elevation typically resolved and returned to baseline within 20 minutes of reperfusion. This study developed quantifiable early diagnostic criteria for successful MI and IRI induction based on characteristic ECG changes. These quantifiable ECG parameters provide early diagnostic standards that can significantly streamline and optimize modeling procedures.

Animals↗
PubMed2004

[Comparison of efficacy of three test-systems for identification of Staphylococcus: PBDS (Russia), "STAPHYtest-16" (Check Republic), "API-STAPH" (France)].

The diagnostic efficiency of three test-systems designed for staphylococci identification including the definition of opportunistic errors was comparatively studied. The identification results coincidence (IRC) made, versus the reference method, 57 +/- 14% for Staphylococci Differentiation Biochemical Plate (SDBP--Russia) 73.83 +/- 3.6% for STAPHYtest-16 (Check Republic) and 58.33 +/- 5.03% for API-Staph (France). The diagnostic efficiency of the studied test-systems was found to be in proportion with the total information density of the identification tests belonging to each of them, which could be used for determining an optimal test list that would ensure the maximum diagnostic effect with minimal cost.

Bacteriological Techniques↗
PubMed1999

Spiral CT of the abdomen: increased diagnostic potential.

Over the last 10 years, spiral CT has become the optimal method of performing all CT within the abdomen and pelvis. Not only has the technique improved the quality of individual examinations, it has also opened up many new diagnostic possibilities which are currently being evaluated and compared with the concurrent advances in ultrasound and MRI. These new diagnostic possibilities are discussed in this review article. So too are the economic advantages of the shorter data-acquisition times which also make the examination much better tolerated by the patient.

Acute Disease↗
PubMed2004

Acquisition protocol considerations for combined PET/CT imaging.

UNLABELLED: Since its introduction in 1998, dual-modality PET/CT imaging has received great attention in the medical community. For the first time, patients can be examined with both CT and PET in a single examination. A whole-body survey is the standard mode of acquisition. The CT images are used for anatomic reference of the tracer uptake patterns imaged in PET, as well as for attenuation correction of the PET data. The routine use of CT-based attenuation correction and user preferences for the quality and type of the CT examination have led to the introduction of different PET/CT scanning protocols. DISCUSSION: Two general approaches to PET/CT imaging can be distinguished today. One uses CT as a fast transmission source with little additional information for anatomic labeling. The other uses CT as a fast transmission source as well as a state-of-the-art diagnostic tool to maximize image quality using optimal acquisition parameters together with oral and intravenous contrast agents. Variations of these approaches share common concerns about image artifacts that result from mismatches in respiration and patient positioning between the CT and the PET examinations. Protocol requirements for the more complex radiologic PET/CT scenario also include alternative contrast application schemes or modifications to the attenuation correction procedure to handle CT contrast agents appropriately. CONCLUSION: High-quality PET/CT studies can be provided routinely with existing PET/CT technology that is used efficiently by trained and motivated technologists and physicians. Only then will the potential diagnostic benefit of this new imaging modality be explored fully.

Artifacts↗
PubMed1997

Adrenal cortical carcinoma associated with venous tumour thrombus extension.

OBJECTIVE: To report the diagnosis and treatment of six patients with adrenocortical adenocarcinoma and venous tumour thrombus extension. PATIENTS AND METHODS: All six patients (four female and two male, age range 14-83 years) were approached surgically through a thoracoabdominal incision and all underwent radical ablative surgery with removal of the primary tumour, regional retroperitoneal lymphadenectomy and en bloc extraction of the venous tumour thrombus. RESULTS: Five patients with right-sided tumours had vena caval tumour thrombus involvement and one patient with a left-sided tumour had extension of tumour thrombus into the splenic vein. All patients had appropriate radiographic evaluation pre-operatively and all underwent successful radical surgery with en bloc resection of the venous tumour thrombus. CONCLUSION: For optimal management of this rare neoplasm, it is paramount that accurate diagnostic imaging be performed pre-operatively to help dictate the ideal surgical approach and to optimize successful treatment of this disease.

Adolescent↗
PubMed1995

Image quality, the ideal observer, and human performance of radiologic decision tasks.

The quality of medical images must be quantified with reference to specific diagnostic tasks. Image quality is limited by fundamental physics, engineering limitations, radiation safety concerns, and imaging time constraints (among other things). There is now a gold standard for assessing human visual decision performance: the ideal Bayesian observer. Unfortunately, there are no mathematical tools to use this gold standard for realistically complex tasks. As an alternative, one can use the optimum linear discriminator (Fisher-Hotelling) model as a silver standard while en route to clinical realism. The goal of scientists working in the area is to develop mathematical models of human observers that will help equipment designers to optimize design trade-offs for specific diagnostic tasks. The current strategy is to modify the Fisher-Hotelling model to include certain limitations of the human observer visual system. The model must be both robust enough and mathematically tractable enough to be used to predict performance for clinical classification and estimation tasks. Statistical models also must be developed that describe realistic signals (lesions and abnormalities) and the normal patient structure that is the background in which these signals must be detected or identified.

Decision Making↗
PubMedDate not supplied

The clinicopathologic significance of vitreous fluid cytology examinations in a series of 38 patients.

The authors systematically analyze a series of 38 patients having a total of 40 vitreous fluid cytology determinations. Nine of the 38 patients (23.7%) have cytologic results diagnostic for, or at least highly suggestive of, a specific disease process. These include two cases of bacterial endophthalmitis; two cases of fungal endophthalmitis; one case of vitreal amyloidosis; and four cases called positive for intraocular lymphoma. There are no vitreous fluid cytology determinations falsely positive or falsely negative for malignancy in this series. Intraocular lymphoma and the increasingly important role of vitreous fluid cytology examination in its diagnosis are discussed. The authors conclude that a strong commitment to quality control concepts, including detailed clinical follow-up, is essential in order to develop clinician trust and help achieve optimal patient care benefit from this valuable diagnostic modality.

Adolescent↗
PubMed2003

Quantification of left ventricular mechanical dyssynchrony by conductance catheter in heart failure patients.

Mechanical dyssynchrony is an important codeterminant of cardiac dysfunction in heart failure. Treatment, either medical, surgical, or by pacing, may improve cardiac function partly by improving mechanical synchrony. Consequently, the quantification of ventricular mechanical (dys)synchrony may have important diagnostic and prognostic value and may help to determine optimal therapy. Therefore, we introduced new indexes to quantify temporal and spatial aspects of mechanical dyssynchrony derived from online segmental conductance catheter signals obtained during diagnostic cardiac catheterization. To test the feasibility and usefulness of our approach, we determined cardiac function and left ventricular mechanical dyssynchrony by the conductance catheter in heart failure patients with intraventricular conduction delay (n = 12) and in patients with coronary artery disease (n = 6) and relatively preserved left ventricular function. The heart failure patients showed depressed systolic and diastolic function. However, the most marked hemodynamic differences between the groups were found for mechanical dyssynchrony, indicating a high sensitivity and specificity of the new indexes. Comparison of conductance catheter-derived indexes with septal-to-lateral dyssynchrony derived by tissue-Doppler velocity imaging showed highly significant correlations. The proposed indexes provide additional, new, and quantitative information on temporal and spatial aspects of mechanical dyssynchrony. They may refine diagnosis of cardiac dysfunction and evaluation of interventions, and ultimately help to select optimal therapy.

Aged↗
PubMed1988

Effect of image enhancement for detectability of bone lesions in digitized intraoral radiographs.

Digital image enhancement is concerned with the computer-controlled manipulation of image information. The aim of this study was to evaluate whether diagnostic accuracy would improve in digitally enhanced images of radiographs with impaired density. Each of 83 dry mandibles was divided into four regions. By random assignment it was decided for each region whether or not a hole should be drilled. Three intraoral radiographs (3 x 4 cm) were performed of each region at different exposure times: 2.0 s, 0.60 s, and 0.16 s and interpreted. The radiographs were thereafter recorded by a video camera connected to an IBM-PC. The personal computer held a hardware digitization card defined at a 512 x 512 x 8 matrix resolution on the basis of which a software program with image enhancement facilities was developed. The light and dark radiographs were digitally enhanced by the use of contrast stretching and smoothing filters. The light (0.16 s) original radiographs were less accurate than the ones with optimal density (0.60 s) while no significant differences were found between dark (2.0 s) and optimal density original radiographs. No significant differences were found between original and digitized radiographs of optimal density and digitally enhanced images of light or dark radiographs. The diagnostic accuracy obtained from optimal density radiographs can thus be maintained in digitized dark radiographs and in light radiographs with a four-times dose reduction after digital image enhancement.

Animals↗
PubMed1984

[Complex diagnosis of bronchial cancer].

The necessity and the value of early complex diagnostics of the bronchial carcinoma as a supposition for an optimal treatment is discussed. To avoid any delay, an immediate admission to a high specialized clinic, where all necessary diagnostic methods are available, must be desired. Our own investigations show the importance of several symptoms often neglected. A view of the diagnostic methods in use since many years and their results are given. Endoscopy and endoscopic biopsies are further indispensable methods with a high diagnostic yield in the diagnosis of bronchial carcinoma. The use and the efficiency of different methods depend on an exact clinical and radiological localization of the tumor.

Biopsy↗
PubMed2005

Molecular imaging in the clinical arena.

Molecular imaging is an emerging field that aims to integrate patient-specific and disease-specific molecular information with traditional anatomical imaging readouts. The information provided by this field may ultimately allow for noninvasive or minimally invasive molecular diagnostic capabilities, better clinical risk stratification, more optimal selection of disease therapy, and improved assessment of treatment efficacy. In this update, we first provide an overview of clinically relevant molecular imaging technologies and imaging agents. Next, their applications to disease detection, drug discovery, and biomedical research are discussed. To specifically demonstrate the potential of molecular imaging, we highlight recent advances in clinical and preclinical molecular imaging of cancer and atherosclerosis.

Biotechnology↗
PubMed2006

Guidance for National Tuberculosis Programmes on the management of tuberculosis in children. Chapter 1: introduction and diagnosis of tuberculosis in children.

About one million children develop tuberculosis (TB) annually worldwide, accounting for about 11% of all TB cases. Children with TB differ from adults in their immunological and pathophysiological response in ways that may have important implications for the prevention, diagnosis and treatment of TB in children. There is an urgent need to improve the diagnosis and management of children with TB, and the prevention of TB in children, by ensuring their inclusion under the implementation of the Stop TB strategy by National TB Programmes. Critical areas for further research include a better understanding of the epidemiology of childhood TB, vaccine development, the development of better diagnostic techniques, new drug development, and the optimal formulations and dosing of first- and second-line TB drugs in children. Specifically regarding the diagnosis of TB in children, this relies on a careful and thorough assessment of all the evidence derived from a careful history, clinical examination and relevant investigations, e.g., tuberculin skin test, chest radiograph and sputum smear microscopy. Although bacteriological confirmation of TB is not always possible, it should be sought whenever possible, e.g., by sputum microscopy in children with suspected pulmonary TB who are old enough to produce a sputum sample. A trial of treatment with TB medications is not generally recommended as a method to diagnose TB in children. New, improved diagnostic tests are urgently needed.

Child↗
PubMed1996

Scales, diagnoses, and child psychopathology: II. Comparing the CBCL and the DISC against external validators.

Using a multimethod multistage screening procedure, the authors interviewed 201 parents and their children with the Diagnostic Interview Schedule for Children (DISC 2.1). In addition, parents completed the Child Behavior Checklist (CBCL) and other survey measures, while their children completed self-report scales. Receiver operating characteristic (ROC) analyses were done to determine optimal cutpoints on the CBCL, referenced to DISC diagnostic "caseness." DISC diagnoses, DISC "stem" symptoms, CBCL scores, and CBCL ROC-outpoints were compared against "external validators," in order to determine the comparative advantages of each approach for assessing child psychopathology. Overall findings suggest that the controversies about "best" assessment strategies may be artificial: When both assessment approaches are compared using similar methods, they are reasonably comparable. However, highly specific diagnostic categories may show fewer relationships with external validators and may therefore need more systematic validational studies.

Adolescent↗
PubMed2004

Pre-operative localisation of hyperfunctional parathyroid tissue with 11C-methionine PET.

PURPOSE: Previous studies have shown high sensitivity of positron emission tomography (PET) with 11C-methionine in the pre-operative localisation of parathyroid adenoma and hyperplasia. Nonetheless, in secondary and tertiary hyperparathyroidism (HPT) and in patients with recurrent disease, pre-operative localisation of adenomatous (PTA) or hyperplastic tissue is still a problem with all available methods. The aim of this study was to define the optimal imaging protocol and to compare the diagnostic value of 11C-methionine PET and 99mTc-methoxyisobutylisonitrile (MIBI) single-photon emission computed tomography (SPECT): in particular, we wished to define the benefit of 11C-methionine in those patients with inconclusive or negative conventional imaging. METHODS: Thirty highly pre-selected patients with HPT were enrolled. Sixteen patients had primary HPT, 12 patients had secondary HPT, and two patients had recurrences of parathyroid carcinomas. All patients had ultrasound of the neck, dual-phase scintigraphy with 99mTc-MIBI and PET with 11C-methionine. SUV(parathyroid)/SUV(cervical soft tissue) (target-to-background) and SUV(parathyroid tissue)/SUV(thyroid tissue) (target-to-non-target) ratios were calculated. After surgery, histology of specimens was obtained in all patients but one. RESULTS: In 12 patients with secondary or tertiary HPT, 36 hyperplastic parathyroid glands were histologically verified. Twenty-five of 36 lesions (69%) were detected with 11C-methionine PET and 17 (47%) with 99mTc-MIBI scintigraphy. PET studies were positive in 17/18 (94%) cases in which HPT was related to adenomas or carcinomas. 99mTc-MIBI scintigraphy/SPECT yielded pathological lesions in 9/18 cases (50%). All eight atypical localisations of parathyroid glands were detected with PET but only six of the eight were detected with 99mTc-MIBI scintigraphy/SPECT. In 10/11 patients with recurrent HPT and non-diagnostic scintigraphy/SPECT, hyperfunctional parathyroid tissue was identified with 11C-methionine PET. The highest SUV(parathyroid)/SUV(cervical soft tissue) ratio was found 10 min, and the highest SUV(parathyroid tissue)/SUV(thyroid tissue) ratio 40 min post injection. In three patients clear delineation of hyperfunctional tissue was only achieved after 40 min post injection. CONCLUSION: 11C-methionine PET is a clinically useful method in highly pre-selected patients with recurrent primary HPT as well as in secondary and tertiary HPT if ultrasound and 99mTc-MIBI SPECT are inconclusive or negative. PET imaging of atypical PTA localisations is more accurate than conventional scintigraphy. In order to achieve optimal contrast of parathyroid glands versus thyroid tissue and adjacent soft tissue, imaging at both 10 min and 40 min is recommended.

Adult↗