[Computed tomography of the prostate: initial clinical trial of ACTA scanner (author's transl)].
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Aged↗
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Results for “Tomography Scanners, X-Ray Computed”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
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Performance of evaluation of computed tomography scanners using a phantom model.
A phantom was designed to test computed tomography (CT) scanner performance relative to spatial resolution, contrast resolution, field uniformity, spatial linearity, artifact resistance, and radiation dose. Translate/rotate, stationary detector with rotating x-ray tube, and rotate-only scanners were tested under conditions that produced the best possible results for each machine within the dose ranges used in clinical practice. Machines can be ranked according to results for each parameters tested. The range of performance exhibited on machines tested was unrelated to class of scanner. Further, machine dedication to a particular body region did not necessarily secure superior results for that region. Spatial resolution at low contrast levels (poor on most machines) seems to be the most sensitive test of performance.
Humans↗
Clinical experience with the E.M.I. scanner.
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Brain Diseases↗
Editorial: Another scanner from EMI.
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Brain↗
Efficiency of utilization of a computed tomography scanner.
Efficient utilization of diagnostically effective but expensive computed tomography (CT) brain scanners requires understanding of time factors influencing patient throughput. In a study at UCLA Medical Center using an EMI Mark I brain scanner, the average number of patients studied was 16.3 per 15.5 hr workday, for an average of 52.7 min per patient. Of the patients, 51.5% were inpatients at UCLA, 45% received intravenous iodinated constrast infusion, and 33% had studies showing significant abnormalities. The x-ray tube was on 51.1% of the time the scanner facility was open, with scanning averaging 34.6 min per patient. The average number of images obtained was 10.4 per patient at 3.4 min per image. Patient handling, including contrast infusion, accounted for an additional 16.2 min per patient or 34.4% of the total time utilization. Anesthesia lengthened the procedure by 1 hr but was needed in only 4.5% of the cases. Flexible scheduling was essential, since 14% of the patients failed to keep their appointments or had their studies cancelled. These timing data suggest that the faster, more expensive CT scanners being introduced, while having diagnostic advantage for body scanning, will not significantly decrease cost per patient when used for brain scanning compared with the first generation machine studied.
Appointments and Schedules↗
Computed tomographic scanning in children: comparison of radiation dose and resolving power of commercial CT scanners.
Surface and internal radiation doses for abdominal computed tomography (CT) of children were determined using child-sized phantoms and seven models of CT body scanners. Resolving power of each scanner was determined simultaneously with the radiation dose determination. The average surface skin dose for a complete CT body examination ranged from 0.39 to 5.60 rad, varying with patient size and model of CT scanner employed. A high contrast (12%) resolving power phantom of water-filled holes in acrylic showed a range of 1.75--2.25 mm.
Child↗
Comparison of E.M.I. and radioisotope imaging in neurological disease.
A comparison has been made between the information provided by isotope imaging--before and after the introduction of E.M.I.-scanning--and E.M.I.-scanning itself. E.M.I.-scanning is superior to isotope imaging (also called scintigraphy) with the gamma camera and the rectilinear scanner in the amount and quality of information provided.
Acute Disease↗
Neurologic computed tomography in a defined population group.
A total of 766 residents of Olmsted County, Minnesota, underwent neurologic computed tomography (CT) from June 1973 through 1976; 981 scans were performed. The number of CT scans per 1,000 population increased each year and, during the period studied, the average rate based on the initial scan in each case was 2.4 and the rate based on all scans was 3.1. The age-specific rates were greatest among patients 65 years old or older. If CT use plateaus at about 6 scans per 1,000 population, then under conditions similar to those in this community, a population of approximately 400,000 would be required to assure adequate use of a CT scanner for investigating neurologic disease.
Adolescent↗
Coronal computed tomography: indications and accuracy.
The application of wide aperture scanners to neuroradiology permits improved anatomic definition and localization of intracranial and intraorbital lesions. Coronal scans are most useful in demonstrating lesions of the skull base and apex, distinguishing between infra- and supratentorial lesions, and in determining if a lesion is intra- or extraaxial. Limitations of coronal scans include discomfort in positioning, high spatial frequency artifacts, and additional radiation exposure.
Adult↗
Evaluating cost-effectiveness of diagnostic equipment: the brain scanner case.
An approach to evaluating the cost-effectiveness of high-technology diagnostic equipment has been devised, using the introduction of computerised axial tomography (CAT) as a model. With the advent of CAT scanning, angiography and air encephalography have a reduced, though important, role in investigating intracranial disease, and the efficient use of conventional equipment requires the centralisation of neuroradiological services, which would result in major cash savings. In contrast, the pattern of demand for CAT scanning, in addition to the acknowledged clinical efficiency of the scanner and its unique role in the head-injured patient, ephasies the need for improved access to scanners. In the interest of the patients the pattern of service must change.
Brain↗
Computed tomographic evaluation of the breast.
Experience with a dedicated breast CT scanner (General Electric CT/M) using a contrast medium enhancement technique indicates that CT is superior to mammography, thermography, or physical examination for diagnosing both benign and malignant mammary disease especially in dense, thick, or fibrocystic breasts. CT is capable of diagnosing totally unsuspected early miniature carcinomas. It can identify and differentiate potential precancerous lesions from benign fibrocystic disease, and is the diagnostic tool of choice for evaluating and following severe fibrocystic disease. CT evaluation also affords definitive diagnostic help in instances where the mammographic, thermographic, and/or physical examinations are inconclusive. It can influence immediate surgical intervention or mitigate against an unnecessary biopsy. The study not only demonstrates morphologic changes in the breast but also accurately depicts an altered iodine pool in mammary tissues.
Adult↗
Bone-mineral estimation by computer-assisted transverse axial tomography.
The technique of computer-assisted transverse axial tomography has been exploited by minor modification of an E.M.I. brain scanner to determine measurements of bone-mineral content in distal radius and ulna. Such measurements are possible independent of adipose tissue subcutaneously or within the bone and irrespective of bony contour. Preliminary studies suggest that the accuracy and precision justify further longitudinal studies in the exploration of trabecular bone within vertebral bodies by whole-body computer-assisted tomography.
Adult↗
A Foundation Model Based CT Biomarker for Non-Invasive Prediction of Response to Neoadjuvant Immunochemotherapy in Non-Small Cell Lung Cancer.
Predicting pathological complete response (pCR) to neoadjuvant immunochemotherapy in non-small cell lung cancer (NSCLC) is clinically important yet remains challenging. Here, we introduce a foundation model-derived computed tomography (CT) imaging biomarker established from a multi-center cohort of 702 patients. Specifically, we developed and validated a non-invasive baseline CT-based model for risk stratification of pathological response. To address scanner and protocol heterogeneity, we first built a 3D Vision Mamba-based CT super-resolution model trained on 2494 cases for image standardization. We then fine-tuned a lung cancer-specific CT foundation model from a pretrained 3D model (VoCo) using 6643 chest CT scans. Finally, we constructed a multi-task Swin Transformer that jointly performs risk stratification and segments tumors to generate the imaging biomarker. Across five centers, the model achieved consistently strong generalization (AUC: 0.75-0.87) for pCR prediction. Genomic analysis revealed that the biomarker was independent of tumor mutational burden but significantly associated with TP53 mutations, suggesting an association with a radiogenomic phenotype related to this alteration. Together, these results demonstrate a generalizable and biologically meaningful foundation model-based biomarker for non-invasive risk stratification of pathological response in NSCLC.
Female↗
Effect of CT noise on detectability of test objects.
Three types of test objects were superimposed on noisy backgrounds and observed by 58 subjects: large low-contrast disks to simulate tumors, small disks to simulate calcifications, and bars to simulate blood vessels. Three types of noise were used: random noise, CT noise (reconstructed random noise), and an actual water scan taken with an EMI CT1010 scanner. In addition, each image was smoothed by a factor of two, giving six test patterns altogether. Photographic images were presented to 25 lay observers, while 25 other lay observers and eight radiologists used a viewing console. The photographs produced a slightly lower true positive rate than the console, although the degree of confidence in the identifications was slightly greater. The anticorrelation property of CT noise gives it a "lumpy" structure, which aided the identification of bars but impeded the identification of small disks. Smoothing did not significantly affect the detectability with random noise, but with CT noise, smoothing improved the detectability of bars and large disks.
Humans↗
Associations of High Attenuation Area-Related Proteomic Biomarkers with Fibrotic or Subpleural Interstitial Lung Abnormalities.
Rationale: High-attenuation area (HAA) is a computed tomography (CT) tool that correlates with lung inflammation and fibrosis. Systemic molecular correlates of HAA (e.g., plasma proteins) may inform biological processes involved in interstitial lung disease. Objectives: To identify plasma proteins that associate with HAA and correlate with a higher probability of developing new-onset fibrotic or subpleural interstitial lung abnormalities (ILAs). Methods: Plasma protein levels were measured using a semiquantitative aptamer-based platform in MESA (the Multi-Ethnic Study of Atherosclerosis; N = 5,486) and SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study; N = 1,781). Linear regression models identified HAA-associated proteins after adjustment for demographic and socioeconomic factors, CT scanner parameters, study center, and batch. Associations of HAA-related proteins with new-onset fibrotic or subpleural ILAs were examined in MESA participants with ILA assessments on full-lung CT 10 years later. Immunohistochemical staining of select proteins was performed in lung tissue from pulmonary fibrosis cases. Measurements and Main Results: There were 75 proteins detected that were significantly associated with HAA in MESA and SPIROMICS. Gene Ontology analysis of these proteins identified processes involved in immune cell chemotaxis and cellular growth and apoptosis. Seven proteins were associated with a higher probability of new-onset fibrotic or subpleural ILAs in MESA, and two of these, junctional adhesion molecule-like protein and GTP cyclohydrolase 1 feedback regulatory protein, stained in areas of fibrosis in lung tissue from patients with interstitial lung disease. Conclusions: Plasma proteins associated with more HAA are involved in immune and cellular processes and associate with new-onset fibrotic-subpleural ILA.
Humans↗
Efficacy of computed tomography of the head in changing patient care and health costs: a retrospective study.
Detailed analysis of all neurologic and neurosurgical admissions at Johns Hopkins Hospital for 6 months prior to the second 6 months after installation of a CT head scanner was undertaken in an attempt to identify the effect CT had on health care decisions, costs, and morbidity. Data showed decreased cost of more than $2,000 per patient and shorter length of stay by 7 days in patients with extracerebral collections, and more than $2,500 and 8 days reduction in patients with tumors after CT was in use. A group matched by computer for age, diagnosis, and physician showed decreased costs of more than $2,000 and shortened stay by more than 3 days per hospitalization. Increased costs were shown in patients with cerebrovascular disease after CT. Change in method of workup with fewer invasive studies for all patients (P less than .001) and significant increases in cost of diagnostic workup were demonstrated (P less than .001). There was no change in morbidity and mortality between the two groups. These data suggest that CT of the head may reduce cost and length of hospitalization in certain patient groups and frequently alters patient workup.
Brain Neoplasms↗