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At least 253 records · Page 14Linked to original sources
PubMed2006

[Differential diagnosis of benign and malignant solitary pulmonary nodule with computer-aided detection].

OBJECTIVE: To investigate the morphological features of benign and malignant solitary pulmonary nodules (SPNs) and explore the radiological evidences for the differentiation of SPNs. METHODS: With SPN Dicom View software, we analyzed and compared images obtained from 23 patients with malignant SPNs and 22 patients with benign SPNs who received CT scanning with or without contrast medium injection. RESULTS: The enhancement in malignant SPNs group was significantly higher than in the benign SPNs group (P < 0.0001). The irregular enhancement in malignant SPNs group was significantly higher than in the benign SPNs group (P = 0. 0084). The mean range of enhancement was (45.04 +/- 26.76) HU in malignant SPNs group, which was significantly higher than that in the benign SPNs group [(15.70 +/- 17.84) HU, P = 0.033]. The mean peak enhancement value was (136.09 +/- 41.72) HU in malignant SPNs group, which was significantly higher than in benign SPNs group [ (60.60 +/- 60.27) HU, P = 0.007]. The mean enhancement area was (21.69 +/- 21.01)% in malignant SPNs group and (8.61 +/- 10.83)% in benign SPNs group (P = 0.203). CONCLUSION: The enhancement range and peak enhancement value as well as the morphologically irregular enhancement of SPNs may provide useful information in the clinical radiological diagnosis of SPNs.

Adult↗
PubMed1997

Bacterial endophthalmitis following extracapsular cataract extraction: recommendations for early detection.

OBJECTIVE: To determine the time between the onset of symptoms of endophthalmitis after cataract extraction and presentation to an ophthalmologist and to determine the spectrum of organisms responsible for postoperative endophthalmitis. DESIGN: Case series. SETTING: Tertiary care vitreoretinal service in Toronto. PATIENTS: Thirty-three patients with early (presentation within 2 weeks of surgery) endophthalmitis following extracapsular cataract extraction and intraocular lens implantation performed between January 1989 and December 1992. OUTCOME MEASURES: Time to presentation to an ophthalmologist, duration of symptoms, culture results. RESULTS: Twenty-two patients (66.7%) were documented to experience identifiable symptoms of endophthalmitis before presentation to their ophthalmologist; the mean time of onset of symptoms was 3.6 (standard deviation [SD] 1.7) days after surgery. Of the 22 patients 16 (72.7%) became symptomatic by the fourth postoperative day, and 21 (95.4%) experienced symptoms by the fifth postoperative day. The mean delay between onset of symptoms and presentation was 1.9 (SD 1.6) days. Bacteria were identified in 27 cases (81.8%), confirmed by culture in 23 cases (69.7%). The organisms were gram-positive in 25 (92.6%) of the 27 cases, and coagulase-negative Staphylococcus predominated. CONCLUSIONS: In our series a considerable delay existed between the development of symptoms of endophthalmitis following extracapsular cataract extraction and clinical diagnosis. This delay could be minimized by scheduling routine postoperative visits at 1 and 4 days following cataract surgery.

Adult↗
PubMed1997

Five-year follow-up of asymptomatic patients with negative fecal occult blood test results in whom clinically significant colorectal pathology was detected.

OBJECTIVES: To determine from a 5-yr longitudinal study (a) rate of compliance with follow-up, (b) number of new clinically significant colorectal lesions discovered by sigmoidoscopy or colonoscopy at later examination, (c) number and causes of deaths, and (d) rate of diagnosis of new cancers among 36 asymptomatic patients with negative fecal occult blood tests in whom clinically significant colorectal lesions were found initially by 60-cm flexible sigmoidoscope. METHODS: For the 36 patients, medical records were reviewed throughout the 5-yr study period. These records included pathology reports, results from 60-cm sigmoidoscopy and colonoscopy examinations, and notations from visits to health facilities for reasons other than colorectal examinations. RESULTS: Seventy-one clinically significant lesions were removed during the 5-yr period; 58 were discovered by sigmoidoscopy and 13 by colonoscopy. Also, during the 5-yr period, noncolorectal cancer was diagnosed in six patients, and two patients died of cardiac disease. CONCLUSIONS: Patients who have clinically significant colorectal pathology found by 60-cm sigmoidoscope have a high prevalence of lesions beyond the view of this instrument. Therefore, colonoscopy should be performed when sigmoidoscopy shows clinically significant pathology. Because subsequent examinations show a high incidence of new lesions, rescreening is indicated.

Aged↗
PubMed1997

[The monitoring of post cesarean section uterine scal with B-ultrasonographic and clinical detections].

OBJECTIVE: To find out an effective method for monitoring the healing of uterine incision after cesarean section. METHODS: 1,145 patients with cesarean section were monitored by B-ultrasonography. In 19 patients who revealed fluid mass in uterine incision, 10 cases were treated by percutaneous drainage under sonographic guidance and 9 cases as control. RESULTS: According to sonographic characteristics, uterine incision healing can be divided into three conditions: normal type revealing a smooth strong echo's light band in uterine incision (93.97%), inflammatory type revealing an uneven parenchymatous light mass (3.67%), and fluid mass with inflammation revealing a complex light mass with low echo's or anechoic area (2.36%). There were abnormal clinical signs in most cases of inflammation. The percutaneous drainage therapy showed marked effect. CONCLUSIONS: The monitoring of uterine incision healing by B-ultrasonography plays an important role in preventing late post-partum hemorrhage.

Cesarean Section↗
PubMed1998

[An analysis of the care for a tubercular patient. Problem detection].

OBJECTIVE: Make a epidemiological and descriptive analysis of the tuberculosis patients care, researching problems which may be the etiology of the increase of illness. DESIGN: Descriptive observing retrospective study. SETTING: Soria County. PATIENTS: 186 cases with positive Mycobacterium tuberculosis culture, since January 1, 1983 until December 31, 1993. RESULTS: The 65.4% of patients were hospitalized to make the diagnostic and/or to begin treatment. We found delayed diagnostics much as 5.5 years. The mean was 120.9 +/- 244.7 days until the diagnostic was performed, 1991 y 1992 were the highest delayed time to diagnostic years of the study. The diagnostic and control of the 99.5% of patients was done at hospital. Only a 64% of patients could be considered as healthy at the onset of his control. CONCLUSIONS: Most of physicians consider the tuberculosis as a hospital illness, so there are delayed diagnostic and therapeutics and worse control of evolution, therapy compliance and contacts study.

Antitubercular Agents↗
PubMed2003

Detection of object resonances by vibro-acoustography and numerical vibrational mode identification.

Chalk sphere and cylinder resonance frequencies related to compressional and bending modes were detected in water, using vibro-acoustography, a relatively new imaging technique. The variable (radiation) force of low-frequency excitation, produced by intersecting two primary focused ultrasound waves with slightly different frequencies, forces the object to vibrate. The low-frequency acoustic emission field, resulting from object vibration, was detected by a hydrophone. By fixing the object at the focus of the ultrasound beam and sweeping the frequency of one of the primary beams within a chosen bandwidth, it was possible to detect some of the resonance frequencies (those related to compressional and bending modes) via variations in acoustic emission amplitude. Experimental results showed excellent agreement with finite element calculations. This method can be used to characterize the presence of heterogeneities in various media, in the field of materials science or biology.

Journal Article↗
PubMed1999

Time-resolved analysis and visualization of dynamic processes in living cells.

Recent development of in vivo microscopy techniques, including green fluorescent proteins, has allowed the visualization of a wide range of dynamic processes in living cells. For quantitative and visual interpretation of such processes, new concepts for time-resolved image analysis and continuous time-space visualization are required. Here, we describe a versatile and fully automated approach consisting of four techniques, namely highly sensitive object detection, fuzzy logic-based dynamic object tracking, computer graphical visualization, and measurement in time-space. Systematic model simulations were performed to evaluate the reliability of the automated object detection and tracking method. To demonstrate potential applications, the method was applied to the analysis of secretory membrane traffic and the functional dynamics of nuclear compartments enriched in pre-mRNA splicing factors.

Animals↗
PubMed2001

Repetition related ERP effects in a visual object target detection task.

ERP responses to initial and repeated presentations of possible and impossible objects were recorded from 61 recording sites in a simple target detection task. In Experiment 1, the non-target objects were line drawings of possible and impossible 3-D geometric figures and the targets were line drawings of familiar everyday objects or combinations of parts of everyday objects. In Experiment 2, the non-target objects were everyday objects and the targets were possible and impossible 3-D geometric figures. In both experiments, at frontal sites, the repeated possible and impossible non-target items elicited less negative ERP waveforms relative to first presentations between 250 and 350-400 ms. At parieto-occipital sites, in both experiments, the repeated possible and impossible non-target items elicited less positive ERP waveforms than did first presentations beginning at about 300 ms. The briefly reduced frontal negativity to repeated items is consistent with familiarity arising from a facilitation of access to conceptual, semantic and visuo-spatial representations during object categorization. The polarity of the parieto-occipital effect was the reverse of what is usually found in stimulus repetition tasks, although it is consistent with earlier work using similar visual stimuli. It is interpreted as reflecting the availability of a newly formed representation (i.e., token) of the object just experienced.

Adolescent↗
PubMed1993

Sensitivity of manual palpation in testing the neonatal hip.

Developmental dysplasia of the hip (DDH) is a term used to describe a group of disorders of the neonatal hip in which the head of the femur is unstable or incongruous in relation to the acetabulum. Early detection and treatment of the condition generally results in normal development, whereas late diagnosis has poor success. In Northern Ireland, despite all neonates being manually examined for hip disorders by a medical officer before hospital discharge, there is an unacceptable late diagnostic rate of almost 50% of all cases. To help reduce the number of late presentations, vibration arthrometry, a noninvasive form of screening for DDH, has been used to record hip vibration events during clinical testing. In a comparative study, 300 infants were examined by nurses and medical officers to establish the sensitivity of manual palpation to neonatal hip vibrations detected by the objective detection system. Experienced research nurses detected 86% of the signals; doctors in training detected less than 10%. This suggests that objective, noninvasive screening by vibration arthrometry would detect a higher proportion of vibration events in neonates during the early stages of DDH. More time should be invested in training medical officers and others involved in DDH screening.

Hip Dislocation, Congenital↗
PubMedDate not supplied

Objective response detection in the frequency domain: comparison of several q-sample tests.

The objective assessment of the hearing threshold requires a suitable statistical test for response detection. For checking the q spectral lines of an auditory-evoked potential spectrum in the frequency domain, a q-sample test seems to be more favourable compared to q applications of a one-sample test. The response detection performance of three q-sample tests (q-sample analogue of Watsons U2 test, q-sample uniform scores test and a modified q-sample uniform scores test) has been checked by extensive Monte Carlo simulations. To compare the performance of the three test statistics, sensitivity was calculated and receiver-operating characteristics were constructed from the probability density functions estimated by the Monte Carlo simulations. In addition, a comparison on the basis of real near-threshold auditory brainstem response data was carried out. The modified q-sample uniform scores test appeared to be the most powerful test. Some aspects of the practical application of this test are discussed in this paper.

Auditory Perception↗
PubMed1998

Detection of object orientation and spatial changes by mice: importance of local views.

This study examines the types of information used by mice to detect changes in their environment. After a period of habituation to an open field containing three bicolored cube-shaped objects, we modified the spatial configuration of the objects or rotated the objects 180 degrees, or both. We noted that whatever the modification, mice reexplored the objects. This shows that mice are able to detect both topological changes and, in particular, changes in the orientation of objects. This is possible only if mice can establish a local view of the objects in relation to a stable element of their environment. A second experiment showed that this stable element is in fact a pattern within the open field and not an element of the distal environment. These two experiments demonstrate the importance of local views in spatial representation for rodents.

Animals↗
PubMed2005

Evaluation of opa-based real-time PCR for detection of Neisseria gonorrhoeae.

OBJECTIVES: Detection of Neisseria gonorrhoeae by commercial and in-house-based assays has been hampered by false-positive and false-negative results. The current study describes a sensitive and specific real-time 5'-nuclease PCR assay targeting a 90-bp region of the multicopy opa gene. GOAL: To evaluate the sensitivity and specificity of this assay in detection of gonococcus. STUDY: Sensitivity and specificity were determined by testing a panel of 173 microorganisms. In addition, 135 clinical samples previously evaluated by 4 nucleic acid amplification methods were also tested. RESULTS: A sensitivity of 1 copy per reaction was achieved. Positive results were only obtained for N gonorrhoeae strains including 20 cppB-negative strains. Overall, 134 of 135 clinical sample results agreed with the consensus nucleic amplification methods. CONCLUSION: This study demonstrates opa-based target can be used as an accurate and rapid PCR assay for the detection of N gonorrhoeae in clinical specimens.

Bacterial Outer Membrane Proteins↗
PubMed2006

System for deep venous thrombosis detection using objective compression measures.

A system for objective vessel compression assessment for deep venous thrombosis characterization using ultrasound image data and a sensorized ultrasound probe is presented. Two new objective measures calculated from applied force and transverse vessel area are also presented and used to describe vessel compressibility. A modified star-Kalman algorithm is used for feature detection in acquired ultrasound images, and objective measures of vessel compressibility are calculated from the detected features and acquired force and location data from the sensorized probe. A three-dimensional shape model of the examined vessel that includes compressibility measures mapped as colors to its surface is presented on the user interface, as well as a virtual representation of the image plane. The compressibility measures were validated using expert segmentation of healthy and diseased vessels and compared using paired t-tests, which showed a significant difference between healthy and diseased cases for both measures. 100% sensitivity and specificity were obtained for both measures. The system was implemented in real-time (16 Hz) and evaluated using a tissue phantom and on healthy human subjects. Sensitivity was 100% and 60%, while specificity was 97% for both measures when implemented. The initial results for the system and its components are promising.

Algorithms↗
PubMed1987

Automation of routine clinical chromosome analysis. II. Metaphase finding.

Metaphase finding is an essential activity in chromosome analysis, and there is much to gain from its automation. This paper describes software for automatic metaphase finding developed for use as part of a routine clinical chromosome analysis system, principally for samples from blood and amniotic fluid. Since the metaphase finding and analysis programs were intended to be used widely in clinical laboratories, cost and portability were important design features. The metaphase finder has been implemented on a moderately priced, general-purpose image analyzer (Magiscan 2), which controls a standard research microscope with motorized stage and focus. Metaphases are detected using fast gray-level processing on whole fields of view, followed by binary processing to produce a figure of merit for each detected object. Clinical experience has shown that this ability to rank detected objects on the basis of their suitability for analysis is a critical feature in determining the usefulness of an automatic metaphase finder.

Amniotic Fluid↗
PubMed1990

Coordinate frame for symmetry detection and object recognition.

Can subjects voluntarily set an internal coordinate frame in such a way as to facilitate the detection of symmetry about an arbitrary axis? If so, is this internal coordinate frame the same as that involved in determining perceived top and bottom in object recognition and shape perception? Subjects were required to determine whether dot patterns were symmetric. Cuing the subjects in advance about the orientation of the axis of symmetry produced a substantial speedup in performance (Experiments 1 and 3) and an increase in accuracy with brief displays (Experiment 2). The effects appeared roughly additive, with an overall advantage for vertical symmetry; thus, the vertical axis effect is not due to a tendency to prepare for the vertical axis. The cuing advantage was found to depend upon the subject's knowing in advance the spatial location as well as orientation of the frame of reference (Experiment 4). The fifth experiment provided evidence that the frame of reference responsible for these effects is the same as the one that determines shape perception: Subjects viewed displays containing a letter (at an unpredictable orientation) and a dot pattern, rapidly naming the letter and then determining whether the dots were symmetric about a prespecified axis. When the top-bottom axis of the letter was oriented the same way as the axis of symmetry for the dots, symmetry judgments were significantly more accurate. Thus, the results suggest a single frame of reference for both types of judgment. The General Discussion proposes a theory of how visual symmetry may be computed, which might account for these phenomena and also characterize their relation to "mental rotation" effects.

Attention↗
PubMed2002

Limitations of attentional orienting. Effects of abrupt visual onsets and offsets on naming two objects in a patient with simultanagnosia.

It has been proposed that the underlying deficit for some simultanagnosics is the inability to bilaterally orient attention in space due to parietal damage. In five experiments, we examine the performance of a patient with simultanagnosia secondary to bilateral occipito-parietal lesions, IC, in naming pairs of line-drawings. With simultaneous presentation and disappearance of objects (Experiment 1), IC typically named a single object. IC's performance dramatically improved when the two drawings alternated every 500 ms (Experiment 2). This improvement was not due to the abrupt onset of the second drawing "capturing attention", as indicated by the results of Experiment 3. Experiments 4 and 5 demonstrated that the crucial factor in improving IC's performance with simultaneous presentation of visual objects was the offset of one of the two stimuli. We propose that IC's impairment in naming two objects is attributable to the inability to "unlock" attention from the first object detected to other objects in the array. Visual offset of the first object disengages attention from the first object, allowing it to be allocated to the second object.

Aged↗
PubMed1998

Does consistent scene context facilitate object perception?

The conclusion that scene knowledge interacts with object perception depends on evidence that object detection is facilitated by consistent scene context. Experiment 1 replicated the I. Biederman, R. J. Mezzanotte, and J. C. Rabinowitz (1982) object-detection paradigm. Detection performance was higher for semantically consistent versus inconsistent objects. However, when the paradigm was modified to control for response bias (Experiments 2 and 3) or when response bias was eliminated by means of a forced-choice procedure (Experiment 4), no such advantage obtained. When an additional source of biasing information was eliminated by presenting the object label after the scene (Experiments 3 and 4), there was either no effect of consistency (Experiment 4) or an inconsistent object advantage (Experiment 3). These results suggest that object perception is not facilitated by consistent scene context.

Adult↗
PubMed1979

A screening system for cervical cancer cytology.

A system for screening cervical cytological preparations is described which employs the Leitz Texture Analyzer System (E. Leitz, Rockleigh, N. J.) quantitative staining with acridine orange, and a fluorescence standard. The instrumentation scans cells on microscope slides and detects objects which it interprets to be nuclei with excess total nuclear green fluorescence intensity (Previous results employing manual measurements have indicated that normal nuclei do not produce total nuclear green fluorescence greater than a specific absolute intensity level). Detected objects are identified by visual observation. Cells (102,000) from 65 patients (29 normal, 36 abnormal) have been examined. In each abnormal sample, at least one abnormal cell was detected. In over half of the samples, three or fewer other objects (e.g. clumps of polymorphonuclear leukocytes) were detected. These are easily distinguishable from single nuclei, and could be discarded by someone with minimal cytological training.

Cervix Uteri↗