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At least 1,099 records · Page 61Linked to original sources
PubMed1990

Blastic phase of chronic myeloid leukemia (blCML): a proposal for standardization of diagnostic and response criteria.

The selection of optimal treatment among the alternatives that are available is especially difficult in blastic phase of chronic myeloid leukemia (blCML) because of the absence of universally agreed upon criteria for the diagnosis of this phase and the absence of definitions of response. Variable response rates, from less than 10 to greater than 90% have been reported, but the highest response rates, in general, have not been reproducible. The application of strict morphologic, cytogenetic, and molecular biologic studies should provide the means for selection of optimal treatment among the new therapies that will be introduced in the future.

Blast Crisis↗
PubMedDate not supplied

[Photography schedule in x-ray diagnostic facilities using image intensifiers].

To provide optimal informativeness of fluorograms obtained with the help of radiodiagnostic complexes which are provided with luminance amplifiers of roentgen image (ARI), the magnitudes of X-ray radiation power dose, exposure dose on a photo film, roentgen radiation power dose in X-ray inspection regime worked out by the complex to the moment of a signal hit on photography, and tolerable ratio of their external magnitudes had to be chosen in accordance with ARI parameters: magnitude of conversion ratio, photography frequency, operation speed of exposure metering system and communication system of main power supply circuit.

Fluoroscopy↗
PubMed2005

EMBASE search strategies for identifying methodologically sound diagnostic studies for use by clinicians and researchers.

BACKGROUND: Accurate diagnosis by clinicians is the cornerstone of decision making for recommending clinical interventions. The current best evidence from research concerning diagnostic tests changes unpredictably as science advances. Both clinicians and researchers need dependable access to published evidence concerning diagnostic accuracy. Bibliographic databases such as EMBASE provide the most widely available entrée to this literature. The objective of this study was to develop search strategies that optimize the retrieval of methodologically sound diagnostic studies from EMBASE for use by clinicians. METHODS: An analytic survey was conducted, comparing hand searches of 55 journals with retrievals from EMBASE for 4,843 candidate search terms and 6,574 combinations. All articles were rated using purpose and quality indicators, and clinically relevant diagnostic accuracy articles were categorized as 'pass' or 'fail' according to explicit criteria for scientific merit. Candidate search strategies were run in EMBASE, the retrievals being compared with the hand search data. The proposed search strategies were treated as "diagnostic tests" for sound studies and the manual review of the literature was treated as the "gold standard." The sensitivity, specificity, precision and accuracy of the search strategies were calculated. RESULTS: Of the 433 articles about diagnostic tests, 97 (22.4%) met basic criteria for scientific merit. Combinations of search terms reached peak sensitivities of 100% with specificity at 70.4%. Compared with best single terms, best multiple terms increased sensitivity for sound studies by 8.2% (absolute increase), but decreased specificity (absolute decrease 6%) when sensitivity was maximized. When terms were combined to maximize specificity, the single term "specificity.tw." (specificity of 98.2%) outperformed combinations of terms. CONCLUSION: Empirically derived search strategies combining indexing terms and textwords can achieve high sensitivity and specificity for retrieving sound diagnostic studies from EMBASE. These search filters will enhance the searching efforts of clinicians.

Abstracting and Indexing↗
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↗
PubMed1983

A predictive value model for quality control: effects of the prevalence of errors on the performance of control procedures.

A predictive value model has been developed to describe the usefulness of results from quality control tests or procedures. The model shows that the critical parameters are the probability for false rejection, probability for error detection, and prevalence or frequency of occurrence of analytical errors. When prevalence is low, control procedures should have a low probability for false rejection. When prevalence is high, control procedures should have a high probability for error detection. The predictive value model for a quality control (QC) test is analogous to the predictive value model for a diagnostic test, thus suggesting new strategies for optimizing the performance of QC tests.

Diagnostic Errors↗
PubMed2006

In vitro ultrasound-mediated leakage from phospholipid vesicles.

Interest in using ultrasound energy in wound management and intracellular drug delivery has been growing rapidly. Development and treatment optimization of such non-diagnostic applications requires a fundamental understanding of interactions between the acoustic wave and phospholipid membranes, be they cell membranes or liposome bilayers. This work investigates the changes in membrane permeation (leakage mimicking drug release) in vitro during exposure to ultrasound applied in two frequency ranges: "conventional" (1 MHz and 1.6 MHz) therapeutic ultrasound range and low (20 kHz) frequency range. Phospholipids vesicles were used as controllable biological membrane models. The membrane properties were modified by changes in vesicle dimensions and incorporation of poly(ethylene glycol) i.e. PEGylated lipids. Egg phosphatidylcholine vesicles with 5 mol% PEG were prepared with sizes ranging from 100 nm to 1 microm. Leakage was quantified in terms of temporal fluorescence intensity changes observed during carefully controlled ultrasound ON/OFF time intervals. Custom-built transducers operating at frequencies of 1.6 MHz (focused) and 1.0 MHz (unfocused) were used, the I(spta) of which were 46.9 W/cm2 and 3.0 W/cm2, respectively. A commercial 20 kHz, point-source, continuous wave transducer with an I(spta) of 0.13 W/cm2 was also used for comparative purposes. Whereas complete leakage was obtained for all vesicle sizes at 20 kHz, no leakage was observed for vesicles smaller than 100 nm in diameter at 1.6 or 1.0 MHz. However, introducing leakage at the higher frequencies became feasible when larger (greater than 300 nm) vesicles were used, and the extent of leakage correlated well with vesicle sizes between 100 nm and 1 microm. This observation suggests that physico-chemical membrane properties play a crucial role in ultrasound mediated membrane permeation and that low frequency (tens of kilohertz) ultrasound exposure is more effective in introducing permeability change than the "conventional" (1 MHz) therapeutic one. The experimental data also indicate that the leakage level is controlled by the exposure time. The results of this work might be helpful to optimize acoustic field and membrane parameters for gene or drug delivery. The outcome of this work might also be useful in wound management.

Dose-Response Relationship, Radiation↗
PubMed2006

Distinguishing benign and malignant pelvic masses: the value of different diagnostic methods in everyday clinical practice.

OBJECTIVE: To optimize referral to specialized gynaecologists for surgical treatment of ovarian cancer by improving preoperative discrimination between benign and malignant pelvic tumours. STUDY DESIGN: In a prospective multicentre study 143 patients with a pelvic mass were included. At several occasions during the diagnostic work-up the gynaecologist estimated the chance of malignancy (educated guess/expert opinion). MRI in the local setting was suggested for uncertain cases. All MRI images were reviewed by an expert radiologist. The datasheet designed for the study further allowed for determining the risk of malignancy index (RMI). RESULTS: The diagnostic accuracy of the gynaecologist's final estimation of the chance of malignancy and the calculated RMI were comparable (area under the ROC curve of 0.87 and 0.86). MRI did not improve the accuracy of the diagnostic work-up for the study population as a whole. Subgroup analysis did however show improved diagnostic accuracy in cases with an estimated chance of malignancy between 20 and 80% when the MRI was read by an expert radiologist. CONCLUSION: Patient selection for surgery of a pelvic mass should be based on the chance of malignancy as assigned by the referring gynaecologists. In case of uncertainty MRI improves diagnostic accuracy, when judged by an expert.

Adolescent↗
PubMed1999

[Performance assessment of mammographic diagnostic systems: evolution of methods and their application to a digital image study].

INTRODUCTION: "Receiver Operating Characteristic" (ROC) curves are one of the most efficient analysis tools for the complete evaluation of a diagnostic system performance. However this method is limited in visualizing and locating abnormal structures, such as clusters of microcalcifications on mammographic images. Other more refined and complex techniques have also been suggested, where particular statistical hypotheses are assumed, namely the "Free-response ROC" (FROC), the "Alternative FROC" (AFROC) and the "Free-response Forced Error" (FFE) analyses. We studied the theoretical bases of these different methods and their experimental applications to assess the correctness of the hypothetical statistical distributions. MATERIAL AND METHODS: We considered two statistical hypotheses: first, that the false-positive response distribution follows the Poissonian statistics; second, that "signal" and "noise" distributions have a Gaussian trend with different means and variances. Thus, we applied the different methods to the responses given by 8 observers (5 radiologists and 3 medical physicists) who independently evaluated 3 digital mammographic samples. Every sample consisted of 39 images, with 1-15 clusters each (total: 100 clusters). The samples were obtained from 39 images available in an Internet database (sample 1); 2 different digital filters were applied to each image (samples 2 and 3). To collects responses, we provided for two phases: first, every observer visualized and located the clusters at a given confidence level; second, when a false-positive response was given, spontaneously or after forcing, the responses were ordered by decreasing conspicuity. Finally, data were analyzed with a "home-made" software by applying the FROC and AFROC analyses to the data collected in phase 1 and the FFE analysis to those collected in phase 2. RESULTS: We considered the area under the AFROC curve as the most important parameter: the values obtained with the 3 types of analysis are well in agreement within their uncertainties. In particular, the FROC-AFROC agreement did not exceed 5.9% (10 of 14 cases within 2.5%), while the FFE analysis had higher standard deviations associated with the area value (about 10%). The interpolated curves from both FROC and AFROC data were very similar. The three methods had various advantages: the FFE is very simple to calculate and makes the most of the information given by the observer; FROC and AFROC can provide true-positive and false-positive responses on the same image, which permits to optimize the evaluation of a diagnostic system performance. The statistical tools used in the simplest methods are usually integrated with the completeness characteristics of the location of multiple signals on mammograms. CONCLUSIONS: In theory, every method is necessary because it provides additional information to validate the statistical hypotheses under investigation. In fact, when the methods are used to evaluate and compare several diagnostic systems, the results of the three techniques are equivalent. Therefore, choosing a specific technique depends on both available resources and response type all the hypothetical statistical distributions in our study proved correct.

Mammography↗
PubMed2026

Development and validation of a plasma miRNA-CEA biomarker panel for early detection of lung cancer.

Lung cancer remains a leading cause of cancer-related mortality worldwide, underscoring the critical need for early detection to improve patient outcomes. This study aimed to develop and validate a plasma microRNA biomarker panel for the early detection of non-small cell lung cancer in a Japanese cohort. We enrolled 525 participants, comprising 261 LC cases and 264 non-LC controls, divided into optimization and validation cohorts. A 12-miRNA panel was optimized and further combined with CEA to enhance diagnostic performance. The miRNA-alone model demonstrated robust performance in both the optimization (AUC = 77.0%) and validation cohorts (AUC = 77.9%). Integration with CEA significantly improved accuracy, achieving AUCs of 86.2% in optimization and 84.9% in validation, with particularly high performance in late-stage cancers (AUC = 94.4%) and squamous cell carcinoma (AUC = 90.7%). Sensitivity and specificity thresholds were evaluated, enabling model customization for diverse clinical scenarios. These findings highlight the potential of the miRNA-CEA panel as a minimally invasive tool for early LC detection, especially in non-smoking populations.

Humans↗
PubMed2000

[Technique of abdominal ultrasonography in newborn foals and normal findings].

Under field conditions, the diagnosis of foal's diseases relies almost exclusively on the physical examination. As the signs of illness in the equine neonate are frequently vage and non-localizing, the diagnosis of diseases may be problematic. This often causes misinterpretations and leads to ineffective prophylaxis and treatment. The purpose of this study was to evaluate the usefulness of diagnostic ultrasonography of the foal's abdomen under field conditions to provide an optimized technique and to describe the normal findings. Diagnostic ultrasonography of the abdomen was performed after obtaining clinical history and passing the physical examination of 25 foals without signs of abdominal problems. The foals were scanned in a stable box, being restrained by three persons in semi-lateral recumbency. Usually, sedation was not necessary. The ventral abdominal wall was clipped, a generous amount of ultrasound coupling gel was applied and massaged on the skin surface. The ultrasonographic examination was carried out using a portable sector scanner ("Microimager 2000", Ausonics) with 5.0 and 7.5-MHz transducers or a combined 5.0 and 7.5-MHz transrectal linear-array scanner ("450 Enhanced", Pie Medical). Employing the 5.0-MHz sector scanner first, the abdomen was explored from caudal to cranial in left and right semi-lateral recumbency. The 7.5-MHz scanner was used to attain higher resolution of certain structures. The sector scanner turned out to be suitable under field conditions and adequate to examine the abdominal organs. The transrectal linear-array scanner also provided the most important informations, although it was difficult to maintain a good contact area of the scan head. By ultrasonography it was possible to identify the urinary bladder, kidneys, spleen, liver and part of the gastrointestinal tract. Thus, application of ultrasound could successfully be performed on newborn foals under field conditions.

Abdomen↗
PubMed2000

Diagnostic errors in interactive telepathology.

Telepathology (TP) as a service in pathology at a distance is now widely used. It is integrated in the daily workflow of numerous pathologists. Meanwhile, in Germany 15 departments of pathology are using the telepathology technique for frozen section service; however, a common recognised quality standard in diagnostic accuracy is still missing. In a first step, the working group Aurich uses a TP system for frozen section service in order to analyse the frequency and sources of errors in TP frozen section diagnoses for evaluating the quality of frozen section slides, the important components of image quality and their influences an diagnostic accuracy. The authors point to the necessity of an optimal training program for all participants in this service in order to reduce the risk of diagnostic errors. In addition, there is need for optimal cooperation of all partners involved in TP service.

Breast Neoplasms↗
PubMed2006

Robust rigid registration of retinal angiograms through optimization.

Retinal fundus photographs are employed as standard diagnostic tools in ophthalmology. Serial photographs of the flow of fluorescein and indocyanine green (ICG) dye are used to determine the areas of the retinal lesions. For objective measurements of features, the registration of the images is a necessity. In this paper, we employ optimization techniques for registration with the help of 2-parameter translational motion model of retinal angiograms, based on non-linear pre-processing (Wiener filtering and morphological gradient) and computation of the similarity criteria for the alignment of the two gradient images for any given rigid transformation. The optimization methods are effectively employed to minimize the similarity criterion. The presence of noise, the variations in the background and the temporal variation of the fluorescence level pose serious problems in obtaining a robust registration of the retinal images. Moreover, local search strategies are not robust in the case of ICG angiograms, even if one uses a multiresolution approach. The present work makes a systematic comparison of different optimization techniques, namely the minimization method derived from the optical flow formulation, the Nelder-Mead local search and the HCIAC ant colony metaheuristic, each optimizing a similarity criterion for the gradient images. The impact of the resolution and median filtering of gradient image is studied and the robustness of the approaches is tested through experimental studies, performed on macular fluorescein and ICG angiographies. Our proposed optimization techniques have shown interesting results especially for high resolution difficult registration problems. Moreover, this approach seems promising for affine (6-parameter motion model) or elastical registrations.

Algorithms↗
PubMed1984

[Basis for the discreteness of delay and frequency in diagnostic cardiostimulation].

The article presents the metrological, electrophysiological and economic aspects of the substantiation of the choice of the optimal discreteness of impulses and their frequency in diagnostic programmed cardiostimulation. It has been shown that in conducting the intracardiac electrophysiological examination the traditional choice of the discreteness of the interval delta T3 = 10 msec, and the discreteness of the frequency delta Fc = 10 impulses/min does not meet the metrological requirements. From the metrological viewpoint, the minimal values of the discreteness constitute delta T3 = 20 msec and delta Fc = 20 impulses/min, which are compatible with obtaining diagnostic information and thus justified from the clinical and expedient from the economic point of view.

Arrhythmias, Cardiac↗
PubMed1990

Clinical and pathologic correlations in patients with periampullary tumors.

Perioperative data on 87 patients undergoing pancreatoduodenectomy for periampullary tumors were correlated with pathologic study of operative specimens to identify the accuracy of diagnosis and the factors affecting survival. Accuracy of endoscopic retrograde cholangiopancreatography and computed tomography in locating lesions was 75% and 44%, respectively. Histologic diagnosis before or at the time of resection was available in only 61% of the patients. Carcinoma was correctly diagnosed clinically by the pathologist or the surgeon in 95% (83/87) of patients with 4 patients found to have benign disease on final pathologic examination. Intraoperative diagnosis of site of origin was incorrect in 18% (16/87) of patients. In 28% (23/83) of patients, pathologists identified nodal metastatic disease missed by the surgeon. Survival correlated with nodal and margin status and tumor grade. Tumor size demonstrated no predictive capacity. Although preoperative diagnostic accuracy is less than optimal, surgeons can usually diagnose malignant lesions but more often fail to identify tumor origin and nodal disease. We continue to advocate resection for patients with periampullary lesions thought to be malignant and resectable without a positive histologic diagnosis.

Adult↗
PubMed2001

Paget disease of the breast--an easily overlooked disease?

BACKGROUND AND OBJECTIVES: Paget disease of the breast has long been recognized as a distinct clinical disease. The clinical manifestations and outcomes of Paget disease of the breast were reviewed to understand its earlier diagnostic clues and achieve an optimal treatment plan. Patients and Methods Thirty-one patients with Paget disease of the breast were included in this study. The postoperative outcomes and possible related prognostic factors were reviewed and analyzed. RESULTS: The 5-year overall survival was 69%. Nineteen patients (61%, Group A) did not have a palpable breast mass and 12 patients (39%, Group B) had a palpable breast mass. There was significant difference (P < 0.01) in the 5-year overall survival between Group A (94%) and Group B (19%). Group A patients had significantly higher incidences of underlying noninvasive breast carcinoma (73% vs. 8%, P < 0.01) and n0 lymph nodes status (84%vs. 50%, P = 0.043) than those of Group B. CONCLUSIONS: Paget disease of the breast without a palpable breast mass carries a more favorable prognosis. Patients with any nipple complaints deserve a detailed evaluation even in the absence of a palpable breast mass in order not to overlook a favorable disease.

Adult↗
PubMed1989

Magnetic resonance imaging of para-articular and ectopic ganglia.

This study was undertaken to evaluate the efficacy of magnetic resonance imaging in (1) improving preoperative identification of soft tissue ganglia and in (2) enhancing management by defining their origins, attachments, and extensions. Magnetic resonance images of 17 ganglia were evaluated for intrinsic signal, internal structure, overall shape, and relationship to joints and tendon sheaths using a Philips 0.5 Tesla superconductive magnet with receiver dedicated surface coils. Magnetic resonance imaging proved particularly well suited to delineating soft tissue ganglia and characterizing several of their distinctive diagnostic features which are not optimally imaged by other modalities such as computed tomography and ultrasound.

Adolescent↗
PubMed1979

Superficial lesions in Crohn's disease of the small bowel.

Double-contrast examinations of the small bowel were compared with operative specimens obtained within 4 weeks after X-ray evaluation of 20 patients with Crohn's disease. Objective evidence of superficial lesions was submucosal edema and superficial ulcerations observed in the operative specimens. Edema was seen radiographically in 18 of 20 patients. Superficial ulcerations were seen radiographically in 8 of 14 patients. These ulcerations were either single with edematous edges or smaller, multiple, and more uniformly spread. The diagnosis demands a high-quality technique and even then the diagnostic accuracy is not always optimal.

Crohn Disease↗