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Results for “object detection”

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PubMed2026

Human-AI Interaction With AI-Assisted Tumor Overlays in Pediatric Whole-Body Magnetic Resonance Imaging: Exploratory Reader Study.

BACKGROUND: AI tools have the potential to enhance personalized clinical care, particularly in radiology. However, their integration into clinical workflows remains complex, especially in pediatric oncology, where early cancer detection is critical. Children with Li-Fraumeni syndrome (LFS), a rare cancer predisposition disorder, undergo regular surveillance whole-body magnetic resonance imaging (wbMRI), which presents an opportunity for AI-assisted tumor detection. OBJECTIVE: We evaluated the feasibility of an AI-assisted overlay for highlighting tumor-like regions in pediatric surveillance wbMRI and explored how access to the overlay influenced radiologist workflow, candidate-lesion marking behavior, follow-up recommendations, and perceived workload. METHODS: We developed a patch-based AI segmentation model trained on augmented 2D slices from 675 surveillance wbMRI volumes of pediatric patients with LFS. The model was designed to highlight regions with high tumor probability. A reader study was conducted with 2 radiologists who independently reviewed wbMRI cases both with and without AI assistance. We measured evaluation time, number and location of reader-marked candidate lesions, type of follow-up recommendation, and subjective feedback using structured questionnaires. RESULTS: AI assistance altered interpretation workflows for both radiologists, with mixed effects. On average, the time required to evaluate each case increased when using the AI tool for both radiologists. However, one radiologist had an increase in the number of candidate lesion locations selected with the tool, and one had a decrease in the number of candidate lesion locations selected with the tool. Subjective feedback indicated that one of the radiologists reported lower mental demand with the AI tool, while both radiologists reported lower stress with the AI tool. Interrater variability was evident, underscoring the need for personalized calibration of AI tools. CONCLUSIONS: AI-assisted wbMRI interpretation can improve tumor detection in pediatric cancer surveillance by reducing false negatives. However, its influence on workflow efficiency and interradiologist variability highlights the importance of careful implementation. Successful integration requires addressing challenges such as improving the predictive precision of AI models, offering intuitive end-user designs and instructions, and building trust in AI outputs. AI outputs can influence workflow and behavior in reader-specific ways. Clinical translation will require larger, randomized, multireader studies and model refinement to reduce false positives and quantify lesion-level reader performance. This can help ensure better patient outcomes in addition to reduced clinician burnout.

Humans↗

PubMed2025

Noninvasive detection and differentiation of gastric malignancy using cell-free DNA biomarkers.

INTRODUCTION: Gastric cancer remains a major global health burden, with high mortality driven by late-stage diagnoses that limit treatment options and reduce survival. Current diagnostic methods such as endoscopy and biopsy are invasive, resource-intensive, and impractical for large-scale early detection. OBJECTIVES: This study aimed to develop and validate an ensemble machine learning model integrating four cell-free DNA (cfDNA) fragmentomic feature classes derived from 5 × whole genome sequencing (WGS) data to non-invasively differentiate malignant gastric cancer from benign gastric lesions in high-risk or symptomatic patients. METHODS: A total of 681 plasma samples were prospectively collected, comprising 329 from patients with gastric cancer or high-grade intraepithelial neoplasia (HGIN) and 352 from individuals with benign gastric conditions. The dataset was divided into a training cohort (n = 333) and a temporally independent validation cohort (n = 348). An external validation cohort of 305 participants was also included. RESULTS: The ensemble model achieved an AUROC of 0.920 in cross-validation testing on the training cohort, 0.912 in the independent validation cohort, and 0.896 (95% CI 0.860-0.932) in the external cohort. At a pre-specified prediction threshold of 0.402, the model demonstrated 93.3% sensitivity and 71.9% specificity in the validation cohort, yielding a PPV of 71.3% and an NPV of 93.5%. In the external cohort, sensitivity and specificity were 91.7% and 69.1%, respectively (PPV 75.7%, NPV 88.8%). Model scores correlated with clinical stage, tumor grade, and histopathological subtype. Approximately 71% of non-cancer patients could have been spared unnecessary endoscopy. CONCLUSIONS: The cfDNA fragmentomics-based ensemble model enables accurate, non-invasive differentiation between gastric cancer and benign gastric lesions in high-risk or symptomatic patients. This approach demonstrates strong potential as a pre-endoscopy triage tool, supporting earlier detection and more efficient use of diagnostic resources.

Humans↗

PubMed1991

Relationship between head circumference and height in normal adults and in the nevoid basal cell carcinoma syndrome and neurofibromatosis type I.

Occipitofrontal circumference (OFC) was strongly correlated with height in 72 normal Caucasian men (r = 0.28, P = 0.018) and 78 women (r = 0.53, P less than 0.0001). OFC:height ratios were approximately normally distributed in each sex with a mean of 0.326 (standard deviation [sd] = 0.0139) in males and 0.335 (sd = 0.0177) in females. Relative macrocephaly (an OFC greater than the 95th centile for height) was seen in seven of nine probands with the nevoid basal cell carcinoma syndrome (NBCC), eight of 32 non-probands with NBCC, three of four neurofibromatosis type 1 (NF1) probands, and six of nine non-probands with NF1. Thirty-one percent of the non-proband NBCC cases had OFC less than the 50th centile for height, while none of the NF1 cases had this finding. Head size appears to be related to proband status in NBCC, while the evidence suggests that NF1 is a true macrocephaly syndrome. Objective detection of relative abnormalities in head size may aid in syndrome delineation and diagnosis.

Adult↗

PubMed1986

Paucity of subtle myocardial injury after angioplasty delineated with MB CK.

To determine the extent to which PTCA elicits subtle myocardial ischemic injury, 28 patients were studied prospectively. The presence of myocardial injury was assessed by analysis of frequent (q4 hours) serial samples of MB CK, a sensitive and specific marker of myocardial injury. Immediately prior to angioplasty, baseline 12-lead ECGs and blood samples for evaluation of total CK and MB CK were obtained. Additional ECGs were obtained immediately after the procedure and on the following morning, and serial samples for total and MB CK were obtained at 4-hour intervals for 24 hours. Patients requiring cardiac surgery within 24 hours after PTCA were excluded. Samples (n = 203) were assayed by the glass bead method. Total CK rose by more than 20 IU/L in only five patients, four of whom had received intramuscular premedication. Mean MB CK was 3.4 +/- 6.1 IU/L at 12 hours and 4.1 +/- 4.7 IU/L at 24 hours compared to 3.1 +/- 1.7 IU/L prior to angioplasty. Only one patient with obvious infarction had a value for MB CK above the normal range. Thus, uncomplicated PTCA is not accompanied by objectively detectable subtle myocardial injury.

Angioplasty, Balloon↗

PubMed1988

Imaging system for morphometric assessment of absorption or fluorescence in stained cells.

An image acquisition and processing system has been developed for quantitative microscopy of absorption or fluorescence in stained cells. Three different light transducers are used in the system to exploit the best characteristics of these sensors for different biological measurements. A digital scanner, in the form of a linear array charge-coupled device (CCD), acquires data with high spatial and photometric resolution. A color (RGB) camera is employed when spectral information is required for the segmentation of cellular subcomponents. An image-intensified charged-injection device (CID) camera provides for very low light intensity measurements, primarily for fluorescence-labeled cells. Properties of these transducers, such as contrast transfer function, linearity, and photo-response nonuniformity, have been measured. Two dedicated image processing units were incorporated into the system. The front-end processor, based on a digital signal processor, provides functions such as object detection, raw image calibration, compression, artifact removal, and filtering. The second image processor is associated with the frame memory and includes a histogram processor, a dedicated arithmetic logic unit for image processing functions, and a graphics module for one-bit overlay functions. An interactive program was developed to acquire cell images and to experiment with a range of segmentation algorithms, feature extractions, and other image processing functions. The results of any image operation are displayed on the video monitor. Once a desired processing sequence is determined, the sequence may be stored to become part of a command library and can be executed thereafter as a single instruction.

Algorithms↗

PubMed1989

Reciprocal relationship between mouse germ-cell mutagenesis and basic genetics: from early beginnings to future opportunities.

The scientific foundations for several mammalian germ-line mutagenesis tests in common use today were laid in the 1930s, 1940s, and early 1950s. Subsequent developments in the field have had multiple objectives: detection of mutagenicity of environmental agents (which has led to the development of numerous methodologies), identification of biological and physical factors that affect mutation yield, analysis of the structural nature of the genetic alterations, and assessment of the organismic effects of various types of mutations. Mutagenesis studies have made numerous contributions to basic genetics by generating mutant types that led to elucidation of sex-determining mechanisms in mammals; formulation of the single-active-, or inactive-, X-chromosome hypothesis; correlation of genetic and cytological maps; discovery of genetic "imprinting" phenomena; study of developmental pathways and cell lineages, etc. Particularly useful are sets of complexly overlapping deletions that have been recovered in radiation mutagenesis studies, propagated in breeding stocks, and genetically analyzed; these have constituted prerequisites for molecular genetic studies aimed at development of the DNA structure-function relationships for important genomic regions. Mutagenesis experiments have also served to identify mutagens that are particularly effective in inducing specific types of genetic lesions desired for basic studies. Reciprocally, basic genetics has contributed to the development of mutagenesis tests and has enhanced the value of the specific-locus test by adding to its quantitative capabilities the capability for qualitatively characterizing the actions of mutagens.

Animals↗

PubMed1979

Cytostatic treatment of meningeal blastoses.

Intrathecal treatment with MTX was attempted in patients with diffuse meningeal blastoses. As a rule, symptoms and clinical findings improved rapidly. As objective parameters, the differential cell pictures of the CSF showed dissimilar results during therapy (25 mg MTX weekly i.t.). In leukoses (n = 10) and malignant lymphomas (n = 12), the CSF could be cleared with three exceptions which concerned differentiated tumors. The success was similarly good with meningeal dissemination of a seminoma. Meningeal carcinoses with mammary carcinoma (n = 7) and melanoma (n = 2) showed dissimilar results. No alteration of the cytograms of four bronchial carcinomas and one colon carcinoma was demonstrable. Besides the growth form, the degree of differentiation appears to be decisive for the success of therapy. The labeling index appears to be a useful indicator. Since symptoms and clinical findings often markedly improve even when a success cannot be objectively detected cytologically, an attempt at therapy is always to be recommended.

Breast Neoplasms↗

PubMed1989

Melatonin administered systemically alters the properties of visual cortex cells in cat: further evidence for a role in visual information processing.

The effects of melatonin given systemically at night-time were investigated in the visual system of cats by means of electrophysiological recordings from single cells in the striate cortex (area 17). Following intravenous injection of melatonin, the spontaneous discharge rate (SDR) was found to decrease in the majority of units when compared to control situations. In addition, the amplitude of responses to photic stimulation (moved light bars on a dark background) was augmented. These results reveal that, following application of melatonin, an improved signal-to-noise ratio is found in response to visual stimuli. The physiological source and putative action sites of melatonin are discussed with regard to its physiological role as a neuromodulating substance. The present data, in addition to previous work, suggest that melatonin is involved in visual information processing such as object detection and dark adaptation.

Action Potentials↗

PubMed1989

Knowledge-based approach to sleep EEG analysis--a feasibility study.

A knowledge-based approach to automated sleep EEG (electroencephalogram) analysis is described. In this system, an object-oriented approach is followed in which specific waveforms and sleep stages ("objects") are represented in terms of frames. The latter capture the morphological and spatio-temporal information for each object. An object detection module ("frame matcher"), operating on the frames, is employed to identify what features need to be extracted from the EEG and to trigger the appropriate "specialist"--specialized signal processing modules--to obtain values for these features. This leads to an opportunistic approach to EEG interpretation with quantitative information being extracted from the signal only when needed by the reasoning processes. The system has been tested on the detection of K complexes and sleep spindles. Its performance indicates that the approach followed is feasible and can become a powerful tool for automated EEG interpretation.

Electroencephalography↗

PubMed1977

Echolocation performance of the vampire bat (Desmodus rotundus).

The neotropical vampire bats (Desmodus rotundus) echolocate using ultrasonic pulses like those of the Latin American phyllostomatid bats. In this paper the orally produced echolocation sounds of Desmodus are analysed and the performance of the echolocation system is studied in two-choice training experiments on two vampire bats. Ability to detect objects is relatively limited; both animals were capable of discerning the presence of a 1 cm wide metal strip at a distance of 50 cm, but they failed with 0.5 cm wide strips. The ultrasonic pulses produced at a distance of 50 cm appear to sample an area with a diameter of 2.5 to 3.0 cm (i.e., the solid angle tested with each pulse is 3 degrees to 3 degrees 40' in extent).

Animals↗

PubMedDate not supplied

Arthroscopic treatment of osteochondritis dissecans in the canine shoulder.

Twenty-three shoulders of 21 dogs were treated arthroscopically for osteochondritis dissecans (OCD). Thirteen dogs had bilateral lesions detectable radiographically; however, only two dogs had arthroscopic surgery on both shoulders. Arthroscopic procedures included removal of the osteochondral flap, curettage of the subchondral defect, and partial synovectomy. Fourteen dogs were using the treated limb within 1 day and eight dogs within 2 days, although some lameness may have persisted for several weeks. Force plate evaluation was effective for comparison of preoperative and postoperative mean peak force/body weight (PF/BW) values. Improvement was detected objectively in 9 of the 10 dogs returned for postoperative force plate analysis. All owners were satisfied with the cosmetic results and the rapid return to function.

Animals↗

PubMed1989

Gating of retinal transmission by afferent eye position and movement signals.

Vision in most vertebrates is an active process that requires the brain to combine retinal signals with information about eye movement. Eye movement information may feed forward from the motor control areas of the brain or feed back from the extrinsic eye muscles. Feedback signals elicited by passive eye movement selectively gate retinal outflow at the first relay, the dorsal lateral geniculate nucleus. The gating predominantly facilitates retinogeniculate transmission immediately after eye movement and inhibits transmission when a new steady-state eye position is achieved. These two gating effects are distributed in a complementary fashion across the dorsal lateral geniculate nucleus such that the spatiotemporal activity profile could contribute to object detection and localization.

Action Potentials↗

PubMed1991

Immunofluorescence and morphology of Giardia lamblia cysts exposed to chlorine.

Giardia cyst-like objects detected by immunofluorescence in chlorinated water samples often cannot be positively identified by their morphological appearance. To determine the effect of chlorine on cyst immunofluorescence and morphology, Giardia lamblia cysts were exposed to chlorine for 48 h. The majority of cysts exposed to chlorine concentrations of 1 to 11 mg/liter at 5 and 15 degrees C lost their internal morphological characteristics necessary for identification, but most of them were still detectable by immunofluorescence.

Animals↗

PubMed1975

Receptive fields of cerebellar cells receiving exteroceptive input in a Gymnotid fish.

Single neurons in the caudal lobe of the cerebellum of the weakly electric fish Apteronotus albifrons respond to distortions in the normal electric field produced by the animal. Moving plastic or metal objects as well as a simpler stimulus, a moving electrical dipole, produce adequate distortions of the fish's field to cause the cerebellar cells to respond. The moving dipole stimulated small enough areas of the fish's skin, as determined by the responses of single electroreceptors, to allow maps of the receptive fields of single cerebellar cells to be produced. The receptive fields seen varied widely in complexity from relatively small excitatory or inhibitory areas to larger fields containing multiple excitatory and inhibitory areas usually bordering one another. Most cells studied displayed directional responses. Usually qualitatively different responses resulted from opposite directions of movement, and less frequently units were seen in which no response resulted from movement opposite the direction which caused responses; Varying the rate of stimulus movement caused only small changes in the responses of cerebellar cells; however, motionless stimuli applied over areas of skin known to respond to moving stimuli produced weaker responses of the appropriate sign for that area. Movement seems to be an important component of the stimulus for these cells. Cells were also seen which responded to visual as well as to electroreceptive input. Responses to each of these two modalities presented above were quite different. The cells recorded from frequently displayed burst discharges similar to those produced by Purkinje cells in other lower vertebrates, and most of the cells studied are believed to be Purkinje cells. A somatotopic relationship was found between the position of the center of a receptive field on the fish's body and the position of the cell in the brain. All of the results obtained are compatible with the hypothesis that the caudal lobe of the cerebellum is processing electroreceptive information related to object detection.

Animals↗

PubMed1990

Synodontid catfish: a new group of weakly electric fish. Behavior and anatomy.

Three species of synodontid catfish can produce weak biphasic electric discharges in either continuous or burst-like fashion. The peak-power frequency of these electric organ discharges is around 100 Hz. The electric organ appears to have originated from a sonic muscle: the organ lies dorsal to the swim bladder, contains modified muscle tissue, and is innervated from a motor nucleus located in the caudal medulla. It is possible that synodontid catfish use electric signals in communication and/or object detection.

Animals↗

PubMed1990

Transient lowering of mental activity during performance of a mental task.

To objectively detect the lowering in mental activity during mental tasks, twenty-five male students were given the calculating tasks of adding or subtracting two 2-digit numbers at three grades of task load for 1 hr each. At any task load there was little variation in the percentage of correct responses in successive 5-min periods. There was no difference among the three task loads in the mood states of stress or arousal rated at the end of the task. Among the six bands in eight leads the amplitude of the beta-2 band in the Oz-A1 lead (Oz beta 2) showed the greatest fall corresponding to a drowsy state in one subject. It was judged from this pattern that mental activity might decrease sporadically in half of the subjects, irrespective of the task load. The mean Oz beta 2 amplitudes for all the task loads decreased with work time.

Adult↗

PubMed1992

Coupling of fetal movement and fetal heart rate accelerations as an indicator of fetal health.

OBJECTIVE: The purpose of this study was to determine the clinical value of identified coupling of fetal heart rate (FHR) accelerations (more than five beats per minute for any duration) with objectively detected fetal movements. METHODS: One hundred sixty-six patients underwent routine fetal testing using a Doppler device that recognized both FHR and fetal movements. The coupling index was determined to be the percentage of fetal movements associated with FHR accelerations, and various coupling indices were compared with nonstress test (NST) results. RESULTS: A coupling index above 25% and below 75% compared well with the traditional NST by standard epidemiologic criteria and by the kappa statistic. CONCLUSION: Coupling of even small FHR accelerations and fetal movements could substitute for or replace the NST in antenatal screening.

Female↗

PubMed1992

Cervical rotation lateral flexion test in brachialgia.

The cervical rotation lateral flexion test (CRLF test), developed earlier, was used to examine patients with brachialgia and thoracic outlet syndrome (TOS) symptoms to detect possible restriction of the movement of the first rib. The test was performed for 23 patients, five of them both before and after treatment. The patients were assessed independently by two clinicians to analyze the interobserver reliability. A cineradiographic examination was performed so that any restriction of the movement of the first rib during expiration and inspiration could be detected objectively. The interobserver repeatability of the test was excellent, thus making the cineradiographic examination unnecessary. It is recommended that this test be included in the clinical investigation of all patients with brachialgia with or without radicular pain.

Adult↗