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Sample records for ct head scans

  1. Head CT scan

    Science.gov (United States)

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... hold your breath for short periods. A complete scan usually take only 30 seconds to a few ...

  2. Indications for CT scanning in minor head injuries: a review.

    Science.gov (United States)

    Żyluk, Andrzej

    2015-01-01

    To determine indications for performing head CT following minor head injuries, which allow reducing number of imaging. Based on 15 articles dedicated to this topic, the clinical decision rules were systematically analysed. The Canadian Computed Tomography Head Rule was found to be the most reliable instrument meeting these criteria, characterised by excellent sensitivity of 100% and fairly good specificity of 48-77%. Remaining scales, although very sensitive, showed poor ability to reduce number of "unnecessary" CT scans. Features most predictive for intracranial injuries included: disorientation, abnormal alertness, somnolentia and neurological deficits. Patients with no loss of consciousness and in normal physical condition need only clinical assessment. Indications to head CT scanning are determined by decision rules presented in the article. Use of clinical decision rules may have effect on reducing number of head CT scanning performed "just in a case". Copyright © 2015 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special ... the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT ...

  4. Dose profile study in head CT scans using radiochromic films

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    Ladino G, A. M.; Prata M, A., E-mail: amlgphys@gmail.com [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Diagnostic images of computed tomography generate higher doses than other methods of diagnostic radiology using X-ray beam attenuation. Clinical applications of CT have been increased by technological advances, what leads to a wide variety of scanner in the Brazilian technological pool. It has been difficult to implement dose reduction strategies because of the lack of proper guidance on computed tomography examinations. However, CT scanners allow adjusting acquisition parameter according to the patients physical profile and diagnostic application for which the scan is intended. The knowledge of the dose distribution is important because changes in image acquisition parameters may provide dose reduction. In this study, it was used a cylindrical head phantom in PMMA with 5 openings, what allows dose measurement in 5 regions. In a GE CT scanner, Discovery model of 64 channels, the central slice of the head phantom was irradiated and the absorbed doses were measured using a pencil ionization chamber. Radiochromic film strips were placed in the peripheral and in the central region of the head phantom and was performed a scan of 10 cm in the phantom central region. The scan was performed using the head scanning protocol of the radiobiology service, with a voltage of 120 kV. After scanning, the radiochromic film strips were digitalized and their digital images were used to have the dose longitudinal profiles. The dose values recorded have variation in a range of 18.66 to 23.57 mGy. In the results it was compared the dose index values obtained by the pencil chamber measurement to the dose longitudinal profiles recorded by the film strips. (Author)

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  6. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  7. Computed Tomography (CT) -- Head

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    Full Text Available ... limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, more ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

  8. The value of baseline CT head scans in the assessment of shunt complications in hydrocephalus

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    Cantrell, P. (Alder Hey Children' s Hospital, Liverpool (United Kingdom)); Fraser, F. (Alder Hey Children' s Hospital, Liverpool (United Kingdom)); Pilling, D. (Alder Hey Children' s Hospital, Liverpool (United Kingdom)); Carty, H. (Alder Hey Children' s Hospital, Liverpool (United Kingdom))

    1993-10-01

    The purpose of this study was to determine the value of a baseline CT head scan in the assessment of patients who subsequently presented with symptoms which may have been due to shunt complications (such as blockage or infection). In all these patients the shunt had been inserted in the treatment of hydrocephalus. We conclude that the presence of a baseline scan does not add to the interpretation of CT scans done when the patient presents with symptoms of possible shunt malfunction. (orig.)

  9. SU-F-I-32: Organ Doses from Pediatric Head CT Scan

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    Liu, H; Liu, Q; Qiu, J; Zhuo, W [Institute of Radiation Medicine Fudan University, Shanghai (China); Majer, M; Knezevic, Z; Miljanic, S [Radiation Chemistry and Dosimetry Laboratory, Ruder Boskovic Institute, Zagreb (Croatia); Hrsak, H [Clinical Hospital Centre Zagreb, Zagreb (Croatia)

    2016-06-15

    Purpose: To evaluate the organ doses of pediatric patients who undergoing head CT scan using Monte Carlo (MC) simulation and compare it with measurements in anthropomorphic child phantom.. Methods: A ten years old children voxel phantom was developed from CT images, the voxel size of the phantom was 2mm*2mm*2mm. Organ doses from head CT scan were simulated using MCNPX software, 180 detectors were placed in the voxel phantom to tally the doses of the represented tissues or organs. When performing the simulation, 120 kVp and 88 mA were selected as the scan parameters. The scan range covered from the top of the head to the end of the chain, this protocol was used at CT simulator for radiotherapy. To validate the simulated results, organ doses were measured with radiophotoluminescence (RPL) detectors, placed in the 28 organs of the 10 years old CIRS ATOM phantom. Results: The organ doses results matched well between MC simulation and phantom measurements. The eyes dose was showed to be as expected the highest organ dose: 28.11 mGy by simulation and 27.34 mGy by measurement respectively. Doses for organs not included in the scan volume were much lower than those included in the scan volume, thymus doses were observed more than 10 mGy due the CT protocol for radiotherapy covered more body part than routine head CT scan. Conclusion: As the eyes are superficial organs, they may receive the highest radiation dose during the CT scan. Considering the relatively high radio sensitivity, using shielding material or organ based tube current modulation technique should be encouraged to reduce the eye radiation risks. Scan range was one of the most important factors that affects the organ doses during the CT scan. Use as short as reasonably possible scan range should be helpful to reduce the patient radiation dose. This work was supported by the National Natural Science Foundation of China(11475047)

  10. Knowledge Representation Of CT Scans Of The Head

    Science.gov (United States)

    Ackerman, Laurens V.; Burke, M. W.; Rada, Roy

    1984-06-01

    We have been investigating diagnostic knowledge models which assist in the automatic classification of medical images by combining information extracted from each image with knowledge specific to that class of images. In a more general sense we are trying to integrate verbal and pictorial descriptions of disease via representations of knowledge, study automatic hypothesis generation as related to clinical medicine, evolve new mathematical image measures while integrating them into the total diagnostic process, and investigate ways to augment the knowledge of the physician. Specifically, we have constructed an artificial intelligence knowledge model using the technique of a production system blending pictorial and verbal knowledge about the respective CT scan and patient history. It is an attempt to tie together different sources of knowledge representation, picture feature extraction and hypothesis generation. Our knowledge reasoning and representation system (KRRS) works with data at the conscious reasoning level of the practicing physician while at the visual perceptional level we are building another production system, the picture parameter extractor (PPE). This paper describes KRRS and its relationship to PPE.

  11. Eye lens radiation exposure and repeated head CT scans: A problem to keep in mind

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    Michel, Morgane; Jacob, Sophie [Institute for Radiological Protection and Nuclear Safety, IRSN/DRPH/SRBE/Laboratoire d' Epidemiologie, BP 17, 92 262 Fontenay-aux-Roses (France); Roger, Gilles [Otolaryngology Department, Trousseau Hospital, Paris (France); Pelosse, Beatrice [Ophthalmology Department, Trousseau Hospital, Paris (France); Laurier, Dominique [Institute for Radiological Protection and Nuclear Safety, IRSN/DRPH/SRBE/Laboratoire d' Epidemiologie, BP 17, 92 262 Fontenay-aux-Roses (France); Le Pointe, Hubert Ducou [Radiology Department, Trousseau Hospital, Paris (France); Bernier, Marie-Odile, E-mail: marie-odile.bernier@irsn.fr [Institute for Radiological Protection and Nuclear Safety, IRSN/DRPH/SRBE/Laboratoire d' Epidemiologie, BP 17, 92 262 Fontenay-aux-Roses (France)

    2012-08-15

    Objectives: The deterministic character of radiation-induced cataract is being called into question, raising the possibility of a risk in patients, especially children, exposed to ionizing radiation in case of repeated head CT-scans. This study aims to estimate the eye lens doses of a pediatric population exposed to repeated head CTs and to assess the feasibility of an epidemiological study. Methods: Children treated for a cholesteatoma, who had had at least one CT-scan of the middle ear before their tenth birthday, were included. Radiation exposure has been assessed from medical records and telephone interviews. Results: Out of the 39 subjects contacted, 32 accepted to participate. A total of 76 CT-scans were retrieved from medical records. At the time of the interview (mean age: 16 years), the mean number of CT per child was 3. Cumulative mean effective and eye lens doses were 1.7 mSv and 168 mGy, respectively. Conclusion: A relatively high lens radiation dose was observed in children exposed to repeated CT-scans. Due to that exposure and despite the difficulties met when trying to reach patients' families, a large scale epidemiological study should be performed in order to assess the risk of radiation-induced cataracts associated with repeated head CT.

  12. The profile of CT scan findings in acute head trauma in Orotta ...

    African Journals Online (AJOL)

    disability and makes considerable demands on health services. In developing ... and gender distribution, and CT findings related to acute head ... Conclusion: The high prevalence of head trauma related CT findings justify the use of CT in acute head trauma in. Eritrea. .... education and to earn the livelihood are more prone.

  13. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than ...

  14. Computed Tomography (CT) -- Head

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    Full Text Available ... images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed information on head ...

  15. Alternative oblique head CT scanning technique reduces bone artifact and improves interpretability of brainstem anatomy

    Directory of Open Access Journals (Sweden)

    Sam Douglas Kampondeni

    2010-06-01

    Full Text Available Brainstem pathology due to infections, infarcts and tumors are common in developing countries, but neuroimaging technology in these resource-poor settings is often limited to single slice, and occasionally spiral, CT. Unlike multislice CT and MRI, single slice and spiral CT are compromised by bone artifacts in the posterior fossa due to the dense petrous bones, often making imaging of the brainstem non-diagnostic. With appropriate head positioning, the petrous ridges can be avoided with 40˚ sagittal oblique scans parallel to either petrous ridge. We describe an alternative sagittal oblique scanning technique that significantly reduces brainstem CT artifacts thereby improving clarity of anatomy. With Inst­itutional Ethical approval, 13 adult patients were enrolled (5 males; 39%. All patients had routine axial brain CT and sagittal oblique scans with no lesions found. Images were read by 2 readers who gave a score for amount of artefact and clarity of structures in the posterior fossa. The mean artifact score was higher for routine axial images compared to sagittal oblique (2.92 vs. 1.23; P<0.0001. The mean anatomical certainty scores for the brainstem were significantly better in the sagittal oblique views compared to routine axial (1.23 vs. 2.77; P<0.0001. No difference was found between the two techniques with respect to the fourth ventricle or the cerebellum (axial vs. sag oblique: 1.15 vs. 1.27; P=0.37. When using single slice CT, the sagittal oblique scanning technique is valuable in improving clarity of anatomy in the brainstem if axial images are non-diagnostic due to bone artifacts.

  16. Study of CT head scans using different voltages: image quality evaluation

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    Pacheco de Freitas C, I.; Prata M, A. [Centro Federal de Educacao Tecnologica de Minas Gerais, Centro de Engenharia Biomedica, Av. Amazonas 5253, 30421-169 Nova Suica, Belo Horizonte, Minas Gerais (Brazil); Alonso, T. C. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil); Santana, P., E-mail: iarapfcorrea@gmail.com [Universidade Federal de Minas Gerais, Departamento de Anatomia e Imagem, Av. Prof. Alfredo Balena 190, 30130-100 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography (CT) was introduced to medical practice in 1972. It generates images recognized by high diagnostic potential. CT allows investigation of structures in the human body inaccessible by conventional image methods, replacing invasive methods in many cases. Noise is a kind of variation of brightness observed on CT images, and it is inherent to this method. The magnitude of the noise is determined by the standard deviation of CT numbers of a region of interest in a homogeneous material. The aim of this study is to analyze the noise in head CT images generated by different acquisition protocols using four voltage values. Five different scans were performed using a female Alderson phantom and their images were analyzed with the RadiAnt software. With the average HU values and standard deviation of each scan, the values of noise were calculated in some region of interest. The obtained noise values were compared and it was observed that the 140 kV voltage promotes the in the lower noise in the image, resulting in better image quality. The results also show that the parameters, such as voltage and current, can be adjusted so that the noise can be decreased. Thus, acquisition protocols may be adapted to produce images with diagnostic quality and lower doses in patient. (Author)

  17. National Survey of Radiation Dose and Image Quality in Adult CT Head Scans in Taiwan.

    Directory of Open Access Journals (Sweden)

    Chung-Jung Lin

    Full Text Available The purpose of the present study was to evaluate the influence of different variables on radiation dose and image quality based on a national database.Taiwan's Ministry of Health and Welfare requested all radiology departments to complete a questionnaire for each of their CT scanners. Information gathered included all scanning parameters for CT head scans. For the present analysis, CT machines were divided into three subgroups: single slice CT (Group A; multi-detector CT (MDCT with 2-64 slices (Group B; and MDCT with more than 64 slices (Group C. Correlations between computed tomography dose index (CTDI and signal-to-noise ratio (SNR with cumulated tube rotation number (CTW(n and cumulated tube rotation time (CTW(s, and sub group analyses of CTDI and SNR across the three groups were performed.CTDI values demonstrated a weak correlation (r = 0.33 with CTW(n in Group A. SNR values demonstrated a weak negative correlation (r = -0.46 with CTW(n in Group C. MDCT with higher slice numbers used more tube potential resulting in higher effective doses. There were both significantly lower CTDI and SNR values in helical mode than in axial mode in Group B, but not Group C.CTW(n and CTW(s did not influence radiation output. Helical mode is more often used in MDCT and results in both lower CTDI and SNR compared to axial mode in MDCT with less than 64 slices.

  18. Autopsy Findings of Brainstem in Head Trauma in Comparison with CT Scan Findings in Brain Trauma Ward in Tabriz, Iran

    Directory of Open Access Journals (Sweden)

    Shakeri Bavil Moslem

    2009-10-01

    Full Text Available Computed tomography (CT is now the primary diagnostic method for head trauma because of its ability to demonstrate the nature, extent, sites, and multiplicity of brain injuries. Although there have been numerous reports on the CT findings of most types of intracranial injury, the findings in brainstem injury have not been well described. This study aimed at comparing the autopsy findings of brainstem in head trauma in comparison with CT scan results. Two hundred patients with head trauma, who expired after a period of time of hospitalization, were assessed in a diagnostic value study. Brain stem involvement was determined by autopsy as well as CT scanning of the brain during their hospitalization. The results of the two methods were compared with each other, emphasizing on the type and location of probable lesions in the brain stem. Considering the autopsy as the method of the choice, sensitivity, specificity, positive predictive value (PPV and negative predictive value (NPV of CT scan in brain stem lesions of patients with head trauma were calculated. The effect of primary cause of head trauma, survival time and Glasgow Coma Scale (GCS were evaluated, as well. Brain stem lesions were detected in 39 (19.5% patients in autopsy. However, CT scan revealed brain stem lesions in 23(11.5% cases. The sensitivity, specificity, PPV and NPV of CT scan was 59%, 100%, 100% and 91% respectively. The most common lesions of the brain stem region were as contusion of pons (8.5%, medulla (5% and midbrain (4.5%. There were 6 (3% cases of ponto-medullary junction tearing and 1 (0.5% case of cervico-medullary junction tearing. CT scan is a specific method of evaluating patients with probable brain stem injuries after head trauma, but low sensitivity limits its efficacy. Our results are in conformity with the reports in the literature.

  19. Construction and analysis of a head CT-scan database for craniofacial reconstruction.

    Science.gov (United States)

    Tilotta, Françoise; Richard, Frédéric; Glaunès, Joan; Berar, Maxime; Gey, Servane; Verdeille, Stéphane; Rozenholc, Yves; Gaudy, J F

    2009-10-30

    This paper is devoted to the construction of a complete database which is intended to improve the implementation and the evaluation of automated facial reconstruction. This growing database is currently composed of 85 head CT-scans of healthy European subjects aged 20-65 years old. It also includes the triangulated surfaces of the face and the skull of each subject. These surfaces are extracted from CT-scans using an original combination of image-processing techniques which are presented in the paper. Besides, a set of 39 referenced anatomical skull landmarks were located manually on each scan. Using the geometrical information provided by triangulated surfaces, we compute facial soft-tissue depths at each known landmark positions. We report the average thickness values at each landmark and compare our measures to those of the traditional charts of [J. Rhine, C.E. Moore, Facial Tissue Thickness of American Caucasoïds, Maxwell Museum of Anthropology, Albuquerque, New Mexico, 1982] and of several recent in vivo studies [M.H. Manhein, G.A. Listi, R.E. Barsley, et al., In vivo facial tissue depth measurements for children and adults, Journal of Forensic Sciences 45 (1) (2000) 48-60; S. De Greef, P. Claes, D. Vandermeulen, et al., Large-scale in vivo Caucasian facial soft tissue thickness database for craniofacial reconstruction, Forensic Science International 159S (2006) S126-S146; R. Helmer, Schödelidentifizierung durch elektronische bildmischung, Kriminalistik Verlag GmbH, Heidelberg, 1984].

  20. Open source deformable image registration system for treatment planning and recurrence CT scans : Validation in the head and neck region.

    Science.gov (United States)

    Zukauskaite, Ruta; Brink, Carsten; Hansen, Christian Rønn; Bertelsen, Anders; Johansen, Jørgen; Grau, Cai; Eriksen, Jesper Grau

    2016-08-01

    Clinical application of deformable registration (DIR) of medical images remains limited due to sparse validation of DIR methods in specific situations, e. g. in case of cancer recurrences. In this study the accuracy of DIR for registration of planning CT (pCT) and recurrence CT (rCT) images of head and neck squamous cell carcinoma (HNSCC) patients was evaluated. Twenty patients treated with definitive IMRT for HNSCC in 2010-2012 were included. For each patient, a pCT and an rCT scan were used. Median interval between the scans was 8.5 months. One observer manually contoured eight anatomical regions-of-interest (ROI) twice on pCT and once on rCT. pCT and rCT images were deformably registered using the open source software elastix. Mean surface distance (MSD) and Dice similarity coefficient (DSC) between contours were used for validation of DIR. A measure for delineation uncertainty was estimated by assessing MSD from the re-delineations of the same ROI on pCT. DIR and manual contouring uncertainties were correlated with tissue volume and rigidity. MSD varied 1-3 mm for different ROIs for DIR and 1-1.5 mm for re-delineated ROIs performed on pCT. DSC for DIR varied between 0.58 and 0.79 for soft tissues and was 0.79 or higher for bony structures, and correlated with the volumes of ROIs (r = 0.5, p elastix in HNSCC on planning and recurrence CT scans is feasible; an uncertainty of the method is close to the voxel size length of the planning CT images.

  1. Scatter radiation breast exposure during head CT: impact of scanning conditions and anthropometric parameters on shielded and unshielded breast dose

    Energy Technology Data Exchange (ETDEWEB)

    Klasic, B. [Hospital for pulmonary diseases, Zagreb (Croatia); Knezevic, Z.; Vekic, B. [Rudjer Boskovic Institute, Zagreb (Croatia); Brnic, Z.; Novacic, K. [Merkur Univ. Hospital, Zagreb (Croatia)

    2006-07-01

    Constantly increasing clinical requests for CT scanning of the head on our facility continue to raise concern regarding radiation exposure of patients, especially radiosensitive tissues positioned close to the scanning plane. The aim of our prospective study was to estimate scatter radiation doses to the breast from routine head CT scans, both with and without use of lead shielding, and to establish influence of various technical and anthropometric factors on doses using statistical data analysis. In 85 patient referred to head CT for objective medical reasons, one breast was covered with lead apron during CT scanning. Radiation doses were measured at skin of both breasts and over the apron simultaneously, by the use of thermo luminescent dosimeters. The doses showed a mean reduction by 37% due to lead shielding. After we statistically analyzed our data, we observed significant correlation between under-the-shield dose and values of technical parameters. We used multiple linear regression model to describe the relationships of doses to unshielded and shielded breast respectively, with anthropometric and technical factors. Our study proved lead shielding of the breast to be effective, easy to use and leading to a significant reduction in scatter dose. (author)

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... a stroke, especially with a new technique called Perfusion CT. brain tumors. enlarged brain cavities (ventricles) in ... X-Ray and CT Exams Blood Clots CT Perfusion of the Head CT Angiography (CTA) Stroke Brain ...

  3. Pediatric minor head trauma: do cranial CT scans change the therapeutic approach?

    Science.gov (United States)

    Andrade, Felipe P; Montoro, Roberto; Oliveira, Renan; Loures, Gabriela; Flessak, Luana; Gross, Roberta; Donnabella, Camille; Puchnick, Andrea; Suzuki, Lisa; Regacini, Rodrigo

    2016-01-01

    OBJECTIVES: 1) To verify clinical signs correlated with appropriate cranial computed tomography scan indications and changes in the therapeutic approach in pediatric minor head trauma scenarios. 2) To estimate the radiation exposure of computed tomography scans with low dose protocols in the context of trauma and the additional associated risk. METHODS: Investigators reviewed the medical records of all children with minor head trauma, which was defined as a Glasgow coma scale ≥13 at the time of admission to the emergency room, who underwent computed tomography scans during the years of 2013 and 2014. A change in the therapeutic approach was defined as a neurosurgical intervention performed within 30 days, hospitalization, >12 hours of observation, or neuro-specialist evaluation. RESULTS: Of the 1006 children evaluated, 101 showed some abnormality on head computed tomography scans, including 49 who were hospitalized, 16 who remained under observation and 36 who were dismissed. No patient underwent neurosurgery. No statistically significant relationship was observed between patient age, time between trauma and admission, or signs/symptoms related to trauma and abnormal imaging results. A statistically significant relationship between abnormal image results and a fall higher than 1.0 meter was observed (p=0.044). The mean effective dose was 2.0 mSv (0.1 to 6.8 mSv), corresponding to an estimated additional cancer risk of 0.05%. CONCLUSION: A computed tomography scan after minor head injury in pediatric patients did not show clinically relevant abnormalities that could lead to neurosurgical indications. Patients who fell more than 1.0 m were more likely to have changes in imaging tests, although these changes did not require neurosurgical intervention; therefore, the use of computed tomography scans may be questioned in this group. The results support the trend of more careful indications for cranial computed tomography scans for children with minor head trauma.

  4. Lumbar spine CT scan

    Science.gov (United States)

    CAT scan - lumbar spine; Computed axial tomography scan - lumbar spine; Computed tomography scan - lumbar spine; CT - lower back ... your breath for short periods of time. The scan should take only 10 to 15 minutes.

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... CT is less sensitive to patient movement than MRI. CT can be performed if you have an implanted medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  7. Dosimetric study on head CT scans using adult and newborn phantoms

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    Paiva de O, G. A.; Prata M, A., E-mail: giovanni_paiva@hotmail.com [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography is the radiodiagnostic method that most contributes to the dose deposition in population. Therefore, the dose reductions used in these tests are very important, especially for pediatric patients who have a life expectancy greater than the rest of the population. This study purpose to compare the doses generated from newborns compared to adult patients in head computed tomography scans. Two head phantoms in a cylindrical shape made in PMMA were used, one to adult and another to newborn patient dimensions. The pediatric routine scan protocol from a radiological service was used for the computed tomography scans. They were performed in General Electric Computed Tomography scanner, Bright Speed model with 4 channels. The absorbed dose measurements were performed with a pencil chamber placed into both phantoms. The newborn head phantom was developed in order to compare the amount of absorbed dose by the phantoms when it is used the same acquisition protocol. The dose found for newborn phantom was 29.9% higher than the adult phantom. (Author)

  8. Computed Tomography (CT) -- Head

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    Full Text Available ... CT scanner technique will be adjusted to their size and the area of interest to reduce the ... Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and ...

  9. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... which may be causing hearing problems. determine whether inflammation or other changes are present in the paranasal ... CT scans . CT is not sensitive in detecting inflammation of the meninges —the membranes covering the brain. ...

  10. Computed Tomography (CT) -- Head

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    Full Text Available ... additional view capabilities. Modern CT scanners are so fast that they can scan through large sections of ... remain still during the exam. Many scanners are fast enough that children can be scanned without sedation. ...

  11. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. Different ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  12. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... a sudden severe headache. a blood clot or bleeding within the brain shortly after a patient exhibits symptoms of a stroke. a ... CT scanning may eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a patient's body after a CT examination. X-rays used in CT ...

  13. SU-F-I-46: Optimizing Dose Reduction in Adult Head CT Protocols While Maintaining Image Quality in Postmortem Head Scans

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    Lipnharski, I; Carranza, C; Quails, N; Correa, N; Rajderkar, D; Bennett, J; Rill, L; Arreola, M [University of Florida, Gainesville, FL (United States)

    2016-06-15

    Purpose: To optimize adult head CT protocol by reducing dose to an appropriate level while providing CT images of diagnostic quality. Methods: Five cadavers were scanned from the skull base to the vertex using a routine adult head CT protocol (120 kVp, 270 mA, 0.75 s rotation, 0.5 mm × 32 detectors, 70.8 mGy CTDIvol) followed by seven reduced-dose protocols with varying combinations of reduced tube current, reduced rotation time, and increased detectors with CTDIvol ranging from 38.2 to 65.6 mGy. Organ doses were directly measured with 21 OSL dosimeters placed on the surface and implanted in the head by a neurosurgeon. Two neuroradiologists assessed grey-white matter differentiation, fluid space, ventricular size, midline shift, brain mass, edema, ischemia, and skull fractures on a three point scale: (1) Unacceptable, (2) Borderline Acceptable, and (3) Acceptable. Results: For the standard scan, doses to the skin, lens of the eye, salivary glands, thyroid, and brain were 37.55 mGy, 49.65 mGy, 40.67 mGy, 4.63 mGy, and 27.33 mGy, respectively. Two cadavers had cerebral edema due to changing dynamics of postmortem effects, causing the grey-white matter differentiation to appear less distinct. Two cadavers with preserved grey-white matter received acceptable scores for all image quality features for the protocol with a CTDIvol of 57.3 mGy, allowing organ dose savings ranging from 34% to 45%. One cadaver allowed for greater dose reduction for the protocol with a CTDIvol of 42 mGy. Conclusion: Efforts to optimize scan protocol should consider both dose and clinical image quality. This is made possible with postmortem subjects, whose brains are similar to patients, allowing for an investigation of ideal scan parameters. Radiologists at our institution accepted scan protocols acquired with lower scan parameters, with CTDIvol values closer to the American College of Radiology’s (ACR) Achievable Dose level of 57 mGy.

  14. CT scan of choristoma

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    Moriki, A.; Morimoto, M.; Sada, Y.; Kurisaka, M.; Mori, K.

    1987-02-01

    Choristoma is a rare tumor that occurs in the pituitary gland. The case presented here is a 44-year-old male. A plain CT scan demonstrated a slight high-density mass near the posterior clinoid of the sella turcica, while a moderate and homogeneous enhancing effect and a clear borderline were shown by an enhanced CT scan. A cornal CT scan study showed that the tumor extended from the intrasellar to the suprasellar region. The diagnosis of choristoma was made by means of histology.

  15. Absent or compressed basal cisterns on first CT scan: ominous predictors of outcome in severe head injury.

    Science.gov (United States)

    Toutant, S M; Klauber, M R; Marshall, L F; Toole, B M; Bowers, S A; Seelig, J M; Varnell, J B

    1984-10-01

    The relationship of outcome to the appearance of the basal cisterns as seen on initial computerized tomography (CT) scanning was assessed in 218 consecutive severely head-injured patients entered into the second phase of the National Pilot Traumatic Coma Data Bank. Outcome could be directly related to the status of the basal cisterns on the initial CT scan. The mortality rates were 77%, 39%, and 22% among those with absent, compressed, and normal basal cisterns, respectively. This association between cisterns and outcome was shown to be strong after adjusting for Glasgow Coma Scale (GCS) score (p less than 0.001). The state of the cisterns was more important for those with higher GCS scores (scores 6 to 8) than for those with lower scores (scores 3 to 5). Patients with GCS scores of 6 to 8, with cisterns absent or not visualized, suffered nearly a fourfold additional risk of poor outcome, compared to those with normal cisterns. This indicates that the status of the cisterns can be used as an early noninvasive method of identifying patients at high risk of death or severe disability, in whom the initial neurological examination would potentially suggest otherwise.

  16. Pediatric CT Scans

    Science.gov (United States)

    The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

  17. Cervical spine CT scan

    Science.gov (United States)

    ... defects of the cervical spine Bone problems Fracture Osteoarthritis Disc herniation Risks Risks of CT scans include: ... Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, ...

  18. Computed Tomography (CT) -- Head

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    Full Text Available ... liver, shows up in shades of gray, and air appears black. With CT scanning, numerous x-ray ... ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x- ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... liver, shows up in shades of gray, and air appears black. With CT scanning, numerous x-ray ... cause blurring of the images and degrade the quality of the examination the same way that it ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  1. Computed Tomography (CT) -- Head

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    Full Text Available ... See the Safety page for more information about pregnancy and x-rays. top of page What does ... See the Safety page for more information about pregnancy and x-rays. CT scanning is, in general, ...

  2. Computed Tomography (CT) -- Head

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    Full Text Available ... rays used in CT scans should have no immediate side effects. Risks There is always a slight ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  3. Computed Tomography (CT) -- Head

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    Full Text Available ... is reduced. Though the scanning itself causes no pain, there may be some discomfort from having to ... time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be ...

  4. Computed Tomography (CT) -- Head

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    Full Text Available ... or to plan radiation therapy for brain cancer. In emergency cases, it can reveal internal injuries and ... generated during a CT scan can be reformatted in multiple planes, and can even generate three-dimensional ...

  5. Computed Tomography (CT) -- Head

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    Full Text Available ... tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like ... contrast materials and a metallic taste in your mouth that lasts for at most a minute or ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may ... medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate the need ...

  7. Computed Tomography (CT) -- Head

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    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2017 Radiological ...

  8. Computed Tomography (CT) -- Head

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    Full Text Available ... therapy for brain cancer. In emergency cases, it can reveal internal injuries and bleeding quickly enough to ... cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can even ...

  9. Computed Tomography (CT) -- Head

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    Full Text Available ... you are pregnant and discuss any recent illnesses, medical conditions, medications you’re taking, and allergies. You ... a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple ...

  10. Computed Tomography (CT) -- Head

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    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

  11. Computed Tomography (CT) -- Head

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    Full Text Available ... you have a hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer you some medication to help you tolerate the CT scanning procedure. If an ...

  12. Computed Tomography (CT) -- Head

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    Full Text Available ... headaches, dizziness, and other symptoms of aneurysm, bleeding, stroke and brain tumors. It also helps your doctor ... scanning provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than regular ...

  13. Computed Tomography (CT) -- Head

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    Full Text Available ... headaches, dizziness, and other symptoms of aneurysm, bleeding, stroke and brain tumors. It also helps your doctor ... scanning provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than regular ...

  14. CT head in children

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Padma, E-mail: padma.rao@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia); Bekhit, Elhamy, E-mail: elhamy.bekhit@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia); Ramanauskas, Fiona, E-mail: fiona.ramanauskas@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia); Kumbla, Surekha, E-mail: surekha.kumbla@rch.org.au [Royal Children' s Hospital and the University of Melbourne, Medical Imaging Department, Flemington Road, Parkville, Melbourne, Victoria 3052 (Australia)

    2013-07-15

    The advances in computerized technology (CT) technique over the last few decades have greatly modified imaging protocols in children. The range of pathologies that can now be demonstrated has broadened with the advent of newer techniques such as CT perfusion and the ability to perform complex reconstructions. Increasing speed of scanning and reduction in scan time have influenced the need for sedation and general anaesthetic as well as impacting on motion artefact. Additionally, concerns about radiation safety and avoidance of unnecessary radiation have further impacted on the inclusion of CT in the imaging armamentarium. Justification and image optimisation are essential. It is important to familiarize oneself with the appearances of normal variants or age related developmental changes. CT does however remain an appropriate investigation in a number of conditions.

  15. Computed Tomography (CT) -- Head

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    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... at and passes through the part of the body being examined, recording an image on a special electronic image recording plate. Bones ...

  16. Computed Tomography (CT) -- Head

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    Full Text Available ... can be performed if you have an implanted medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a patient's body after ...

  17. Computed Tomography (CT) -- Head

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  18. Computed Tomography (CT) -- Head

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images ...

  19. Estimation of effective dose and lifetime attributable risk from multiple head CT scans in ventriculoperitoneal shunted children

    Energy Technology Data Exchange (ETDEWEB)

    Aw-Zoretic, J., E-mail: Jaw@luriechildrens.org [Department of Medical Imaging, Ann and Robert H. Lurie Children' s Hospital of Chicago, Chicago, IL (United States); Seth, D.; Katzman, G.; Sammet, S. [Department of Radiology, University of Chicago, Chicago, IL (United States)

    2014-10-15

    Purpose: The purpose of this review is to determine the averaged effective dose and lifetime attributable risk factor from multiple head computed tomography (CT) dose data on children with ventriculoperitoneal shunts (VPS). Method and materials: A total of 422 paediatric head CT exams were found between October 2008 and January 2011 and retrospectively reviewed. The CT dose data was weighted with the latest IRCP 103 conversion factor to obtain the effective dose per study and the averaged effective dose was calculated. Estimates of the lifetime attributable risk were also calculated from the averaged effective dose using a conversion factor from the latest BEIR VII report. Results: Our study found the highest effective doses in neonates and the lowest effective doses were observed in the 10–18 years age group. We estimated a 0.007% potential increase risk in neonates and 0.001% potential increased risk in teenagers over the base risk. Conclusion: Multiple head CTs in children equates to a slight potential increase risk in lifetime attributable risk over the baseline risk for cancer, slightly higher in neonates relative to teenagers. The potential risks versus clinical benefit must be assessed.

  20. A contrast enhancement and scanning techniques for CT angiography of head and neck. One phase injection method for simultaneous imaging of vessels and tumor

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Yasuhiko; Indo, Hiroko; Noikura, Takenori [Kagoshima Univ. (Japan). Dental School

    1999-09-01

    We report on a method of CT-Angiography useful for examining lesion of the head and neck using three-dimensional images and measured CT value. This study focused on some of the important blood vessels in the head and neck. The aim of this method was to obtain high-contrast enhancement for both vessels and tumors at same time. A total amount of 100 ml nonionic contrast media (Omnipaque 240, 240 mg iodine per milliliter, Daiichi seiyaku, Tokyo, Japan) was injected intravenously with a flow of 1.5 ml/sec. Spiral scans, 24 rotations with 24 seconds, were started at a time when remaining amount of contrast media had become 30 to 20 ml. All CT scans were performed using double speed spiral scan technique with a slice thickness of 2 to 3 mm and table speeds from 3 to 5 mm/rotation. The patients populations consisted of 9 men and 6 women who ranged in age from 37 to 85 years. Sixteen CT-angiography were performed according to this method. Mean CT values of major blood vessels were measured in order to find out threshold at the level of submandibular gland in 13 examinations for 12 subjects. Important vessels like the common, internal, and the external artery, internal and external jugular vein were clearly visible in all subjects. Three dimensional images of these vessels could also be reconstructed for 15 of the subjects. Mean CT values were 211 Hounsfield units (HU) and 209 HU for the right and left internal carotid artery, respectively, and 204 HU and 206 HU for the right and left external carotid artery, respectively. Mean CT values for right and left internal jugular vein were 195 HU and 194 HU respectively. Measured CT values at each important blood vessels showed this method could yields acceptable enhancements. Good enhancement effect of tumor and blood vessels in the same scan seems to be mutually incompatible. One very important trade-off is the early enhancement effect at blood vessels versus the late enhancement effect at tumors. The other important trade

  1. Gyral high density on CT scan after head injury; [sup 123]I-IMP SPECT and MRI findings in three children

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Takumi; Matsumoto, Kiyoshi (Showa Univ., Tokyo (Japan). School of Medicine); Sakamoto, Tetsuya; Aruga, Tohru

    1994-02-01

    The authors treated three children who had 'gyral high density' on plain CT scans after head injury with acute subdural hematoma. [sup 123]I-IMP SPECT (IMP) and MRI in the chronic stage were performed. All were males, about one year of age, with acute subdural hematoma. CT scan 48 hours after injury showed diffuse low density in the ipsilateral parenchyma with minimum midline shift, and IMP showed decreased activity in the same area. Plain CT scan 1 to 3 weeks after injury showed remarkably high density along the gyri in part of the same area. This area was markedly enhanced on CT with contrast medium and showed decreased blood flow on IMP. This high density area disappeared within 2 months after injury and the area concerned showed brain atrophy. In the chronic stage (after 6 months), only the high density area along the gyri seen in the CT scan showed MRI evidence of ishemia, but there was no definite evidence of hemorrhage. All three children had hemiplegia at the time of discharge. The gyral high density suggests ischemic brain, but the pathophysiological process might be different from that of so-called hemorrhagic infarction. Presumably, it is due to incomplete autoregulation, the incomplete blood-brain barrier and the sensitivity to stimulation of cerebral blood vessels in the brains of infants. The intensity and range of the gyral high density are considered to be important in estimating the future amount of atrophic change in the insulted brain and the resulting sequelae. (author).

  2. 轻微头部外伤后头部CT扫描对神经外科手术的预测%After Minor Head Trauma Head CT Scan Predict for Neurosurgery

    Institute of Scientific and Technical Information of China (English)

    许俊华

    2015-01-01

    Objective: There continues to be an ongoing debate regarding the utility of Head CT scans in patients with a normal Glasgow Coma Scale (GCS) after minor head injury.The objective of this study is to determine patient and injury characteristics that predict a positive head CT scan or need for a Neurosurgical Procedure (NSP) among patients with blunt head injury and a normal GCS. Methods:Retrospective analysis of adult patients with a history of blunt head injury and a normal GCS,the primary outcomes were a positive head CT scan or a NSP.Multivariate logistic regression controlling for patient and injury characteristics was used to determine predictors of each outcome.Results:Total of 835 patients,250 (29.9%) had a positive head CT scan and 38 (9.9%)underwent a NSP.Older patients and patients with a history of fall (as compared to a motor vehicle crash) were more likely to have a positive finding on a head CT scan.Male patients,and those who presented with a fall were more likely to have a NSP.Conclusion:Older age,male gender,and mechanism of injury are significant predictors of a positive finding on head CT scans and the need for neurosurgical procedures.This study highlights patient and injury specific characteristics that may help in identifying patients with supposedly minor head injury who will benefit from a head CT scan.%目的:本研究的目的是确定钝性颅脑损伤及正常格拉斯哥昏迷评分(GCS)患者采用头部CT扫描预测采取神经手术操作(Neurosurgical Procedure,NSP)的必要。方法:回顾分析钝性颅脑损伤成人患者的临床资料,主要结局为阳性头部CT扫描或NSP。采用多变量回归分析分析损伤特征确定预测因素。结果:835例患者中,250例(29.9%)头部CT阳性,38例(9.9%)经历NSP。年龄更大及跌倒史患者(与效能事故比较)CT阳性的可能性更大。男性跌倒患者更可能经历NSP。结论:年龄较大,男性的性别、损伤的机制

  3. Technical aspects of CT scanning.

    Science.gov (United States)

    Maravilla, K R; Pastel, M S

    1978-01-01

    The advent of computed tomography (CT) has initiated a technological revolution which continues to the present time. A brief review of basic principles of CT scanning is presented, and the evolution of modern CT scanner systems is traced. Some early indications of future trends are also presented.

  4. Cardiac CT Scan

    Science.gov (United States)

    ... combine these pictures to create a three-dimensional (3D) model of the whole heart. This imaging test ... findings from earlier chest x rays. Different CT scanners are used for different purposes. A multidetector CT ...

  5. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... lives. CT has been shown to be a cost-effective imaging tool for a wide range of ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  7. Computed Tomography (CT) -- Head

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  8. Computed Tomography (CT) -- Head

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    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  9. Computed Tomography (CT) -- Head

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    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in ...

  10. Computed Tomography (CT) -- Head

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    Full Text Available ... a stroke. a stroke, especially with a new technique called Perfusion CT. brain tumors. enlarged brain cavities ( ... brain. assess aneurysms or arteriovenous malformations through a technique called CT angiography. For more information, see the ...

  11. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... to urinate; however, this is actually a contrast effect and subsides quickly. When you enter the CT ...

  12. Chest CT Scan

    Science.gov (United States)

    ... can combine these pictures to create three-dimensional (3D) models to help show the size, shape, and ... a medical imaging facility or hospital. The CT scanner is a large, tunnel-like machine that has ...

  13. An optimal set of landmarks for metopic craniosynostosis diagnosis from shape analysis of pediatric CT scans of the head

    Science.gov (United States)

    Mendoza, Carlos S.; Safdar, Nabile; Myers, Emmarie; Kittisarapong, Tanakorn; Rogers, Gary F.; Linguraru, Marius George

    2013-02-01

    Craniosynostosis (premature fusion of skull sutures) is a severe condition present in one of every 2000 newborns. Metopic craniosynostosis, accounting for 20-27% of cases, is diagnosed qualitatively in terms of skull shape abnormality, a subjective call of the surgeon. In this paper we introduce a new quantitative diagnostic feature for metopic craniosynostosis derived optimally from shape analysis of CT scans of the skull. We built a robust shape analysis pipeline that is capable of obtaining local shape differences in comparison to normal anatomy. Spatial normalization using 7-degree-of-freedom registration of the base of the skull is followed by a novel bone labeling strategy based on graph-cuts according to labeling priors. The statistical shape model built from 94 normal subjects allows matching a patient's anatomy to its most similar normal subject. Subsequently, the computation of local malformations from a normal subject allows characterization of the points of maximum malformation on each of the frontal bones adjacent to the metopic suture, and on the suture itself. Our results show that the malformations at these locations vary significantly (p<0.001) between abnormal/normal subjects and that an accurate diagnosis can be achieved using linear regression from these automatic measurements with an area under the curve for the receiver operating characteristic of 0.97.

  14. Computed Tomography (CT) -- Head

    Science.gov (United States)

    ... of a stroke. a stroke, especially with a new technique called Perfusion CT. brain tumors. enlarged brain ... be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... does the equipment look like? The CT scanner is typically a ...

  15. External validation of the New Orleans Criteria (NOC), the Canadian CT Head Rule (CCHR) and the National Emergency X-Radiography Utilization Study II (NEXUS II) for CT scanning in pediatric patients with minor head injury in a non-trauma center

    Energy Technology Data Exchange (ETDEWEB)

    Schachar, Jennifer L. [Albert Einstein College of Medicine, Department of Radiology, Bronx, NY (United States); Zampolin, Richard L.; Miller, Todd S.; Farinhas, Joaquim M.; Taragin, Benjamin H. [Albert Einstein College of Medicine and Montefiore Medical Center, Department of Radiology, Bronx, NY (United States); Freeman, Katherine [Albert Einstein College of Medicine and Montefiore Medical Center, Department of Biostatistics, Bronx, NY (United States)

    2011-08-15

    Head CT scans are considered the imaging modality of choice to screen patients with head trauma for neurocranial injuries; however, widespread CT imaging is not recommended and much research has been conducted to establish objective clinical predictors of intracranial injury (ICI) in order to optimize the use of neuroimaging in children with minor head trauma. To evaluate whether a strict application of the New Orleans Criteria (NOC), Canadian CT Head Rule (CCHR) and National Emergency X-Radiography Utilization Study II (NEXUS II) in pediatric patients with head trauma presenting to a non-trauma center (level II) could reduce the number of cranial CT scans performed without missing clinically significant ICI. We conducted an IRB-approved retrospective analysis of pediatric patients with head trauma who received a cranial CT scan between Jan. 1, 2001, and Sept. 1, 2008, and identified which patients would have required a scan based on the criteria of the above listed decision instruments. We then determined the sensitivities, specificities and negative predictive values of these aids. In our cohort of 2,101 patients, 92 (4.4%) had positive head CT findings. The sensitivities for the NOC, CCHR and NEXUS II were 96.7% (95%CI 93.1-100), 65.2% (95%CI 55.5-74.9) and 78.3% (95%CI 69.9-86.7), respectively, and their negative predictive values were 98.7%, 97.6% and 97.2%, respectively. In contrast, the specificities for these aids were 11.2% (95%CI 9.8-12.6), 64.2% (95%CI 62.1-66.3) and 34.2% (95%CI 32.1-36.3), respectively. Therefore, in our population it would have been possible to scan at least 10.9% fewer patients. The number of cranial CT scans conducted in our pediatric cohort with head trauma would have been reduced had any of the three clinical decision aids been applied. Therefore, we recommend that further validation and adoption of pediatric head CT decision aids in non-trauma centers be considered to ultimately increase patient safety while reducing medical

  16. Body CT (CAT Scan)

    Science.gov (United States)

    ... You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... and surgical biopsy. No radiation remains in a patient's body after a CT ... side effects. Risks There is no conclusive evidence that radiation at ...

  17. A quantitative comparison of gross tumor volumes delineated on [18F]-FDG-PET/CT scan and contrast-enhanced computed tomography scan in locally advanced head and neck carcinoma treated with Intensity Modulated Radiotherapy

    Directory of Open Access Journals (Sweden)

    Nagarjuna Burela

    2017-05-01

    Full Text Available Accurate tumor diagnosis is important in highly conformal techniques such as Intensity Modulated Radiotherapy (IMRT, which aims for high therapeutic ratio. We compared Gross Tumor Volume (GTV (primary and nodal delineated on 18F-fluorodeoxyglucose positron emission tomography ([18F]-FDG-PET scan to those delineated on contrast-enhanced computed tomography (CECT scan and its impact on staging treated by IMRT. A total of 30 consecutive patients with locally advanced squamous cell carcinoma of head and neck were included in this study. FDG-PET and CECT scans were performed with dedicated positron emission tomography–computed tomography (PET/CT scanner in a single session as part of radiotherapy treatment planning for IMRT. After treatment with concurrent chemoradiotherapy, all patients were followed for one year. Three out of 30 patients were excluded from the final analysis, as there was complete remission in PET/CT after neoadjuvant chemotherapy. For remaining 27 cases, the primary sites were 17 oropharynx, 2 hypopharynx, 7 larynx and 1 unknown primary with secondary neck node. PET–CT resulted in changes of CT-based staging in 25% patients (up-staged in 3 and down-staged in 4. GTV delineated on PET vs CT scan was GTV-PET (primary of 20.15 cm3 vs GTV-CT (primary of 18.75 cm3, p = 0.803; and GTV-PET (nodes of 28.45 cm3 vs GTV-CT (nodes of 21.56 cm3, p = 0.589. The mismatch between two target volumes was statistically insignificant (p = 0.635 for GTV primary, p = 0.187 for nodes. The mean GTV-PET outside CT for primary was 5.83 cm3, and for node was 8.47 cm3. Median follow-up was 12 months. One-year loco-regional control was 92%. The target delineation of GTV can be improved with functional imaging [18F]-FDG-PET/CT.

  18. Computed Tomography (CT) -- Head

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    Full Text Available ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ... need for exploratory surgery and surgical biopsy. No radiation remains in a patient's body after a CT ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a patient's body after ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer ... to you, revolve around you during the imaging process. You will be alone in the exam room ...

  1. Computed Tomography (CT) -- Head

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    Full Text Available ... time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer ...

  2. Computed Tomography (CT) -- Head

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    Full Text Available ... hours prior to your exam. Leave jewelry at home and wear loose, comfortable clothing. You may be ... the CT images and should be left at home or removed prior to your exam. You may ...

  3. Computed Tomography (CT) -- Head

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    Full Text Available ... your exam. You should inform your physician of all medications you are taking and if you have ... body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a ...

  4. Computed Tomography (CT) -- Head

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    Full Text Available ... or thyroid problems. Any of these conditions may increase the risk of an unusual adverse effect. The ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  5. Computed Tomography (CT) -- Head

    Science.gov (United States)

    ... an image on a special electronic image recording plate. Bones appear white on the x-ray; soft ... which are then displayed on a monitor. CT imaging is sometimes compared to looking into a loaf ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... an image on a special electronic image recording plate. Bones appear white on the x-ray; soft ... which are then displayed on a monitor. CT imaging is sometimes compared to looking into a loaf ...

  7. Computed Tomography (CT) -- Head

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    Full Text Available ... 10 minutes. top of page What will I experience during and after the procedure? CT exams are ... at most a minute or two. You may experience a sensation like you have to urinate; however, ...

  8. Computed Tomography (CT) -- Head

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    Full Text Available ... during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and ... may increase the risk of an unusual adverse effect. The radiologist also should know if you have ...

  9. Computed Tomography (CT) -- Head

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    Full Text Available ... brain cancer. In emergency cases, it can reveal internal injuries and bleeding quickly enough to help save ... to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide ...

  10. Computed Tomography (CT) -- Head

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ...

  11. Computed Tomography (CT) -- Head

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    Full Text Available ... quickly. When you enter the CT scanner, special light lines may be seen projected onto your body, ... and its references. The risk of serious allergic reaction to contrast materials that contain iodine is extremely ...

  12. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... data suggest that it is safe to continue breastfeeding after receiving intravenous contrast. For further information please ...

  13. Computed Tomography (CT) -- Head

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    Full Text Available ... of electronic x-ray detectors rotate around you, measuring the amount of radiation being absorbed throughout your ... quickly. When you enter the CT scanner, special light lines may be seen projected onto your body, ...

  14. Computed Tomography (CT) -- Head

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    Full Text Available ... lives. CT has been shown to be a cost-effective imaging tool for a wide range of ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  15. Computed Tomography (CT) -- Head

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    Full Text Available ... to remove hearing aids and removable dental work. Women will be asked to remove bras containing metal ... have diabetes —particularly if you are taking Glucophage . Women should always inform their physician and the CT ...

  16. Computed Tomography (CT) -- Head

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    Full Text Available ... to wear a lead apron to minimize radiation exposure. After a CT exam, the intravenous line used ... always a slight chance of cancer from excessive exposure to radiation. However, the benefit of an accurate ...

  17. Computed Tomography (CT) -- Head

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    Full Text Available ... to plan radiation therapy for brain cancer. In emergency cases, it can reveal internal injuries and bleeding ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding ...

  18. CT Perfusion of the Head

    Science.gov (United States)

    ... physicians diagnose and treat medical conditions. CT scanning combines special x-ray equipment with sophisticated computers to ... The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... you! Do you have a personal story about radiology? Share your patient story here Images × Image Gallery ... Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to ...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... special x-ray equipment to help assess head injuries, severe headaches, dizziness, and other symptoms of aneurysm, ... cancer. In emergency cases, it can reveal internal injuries and bleeding quickly enough to help save lives. ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... special x-ray equipment to help assess head injuries, severe headaches, dizziness, and other symptoms of aneurysm, ... cancer. In emergency cases, it can reveal internal injuries and bleeding quickly enough to help save lives. ...

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... and surgical biopsy. No radiation remains in a patient's body after a CT ... side effects. Risks There is always a slight chance of cancer ...

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... circumstances. For example, sometimes a parent wearing a lead shield may stay in the room with their child. However, the technologist will always be able to see, hear and speak with you through ... to wear a lead apron to minimize radiation exposure. After a CT ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other ... another on an x-ray film or CT electronic image. In a conventional x-ray exam, a ...

  6. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... are present in the paranasal sinuses. plan radiation therapy for cancer of the brain or other tissues. guide the ... RTAnswers.org Radiation Therapy for Brain Tumors Radiation Therapy for Head and Neck Cancer Others American Stroke Association National Stroke Association top ...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... is reduced. Though the scanning itself causes no pain, there may be some discomfort from having to ...

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... be needed for children who cannot hold still. Motion will cause blurring of the images and degrade ... to hold your breath during the scanning. Any motion, whether breathing or body movements, can lead to ...

  9. Investigation of a method for generating synthetic CT models from MRI scans of the head and neck for radiation therapy

    Science.gov (United States)

    Hsu, Shu-Hui; Cao, Yue; Huang, Ke; Feng, Mary; Balter, James M.

    2013-12-01

    Magnetic resonance (MR) images often provide superior anatomic and functional information over computed tomography (CT) images, but generally are not used alone without CT images for radiotherapy treatment planning and image guidance. This study aims to investigate the potential of probabilistic classification of voxels from multiple MRI contrasts to generate synthetic CT (‘MRCT’) images. The method consists of (1) acquiring multiple MRI volumes: T1-weighted, T2-weighted, two echoes from a ultra-short echo time (UTE) sequence, and calculated fat and water image volumes using a Dixon method, (2) classifying tissues using fuzzy c-means clustering with a spatial constraint, (3) assigning attenuation properties with weights based on the probability of individual tissue classes being present in each voxel, and (4) generating a MRCT image volume from the sum of attenuation properties in each voxel. The capability of each MRI contrast to differentiate tissues of interest was investigated based on a retrospective analysis of ten patients. For one prospective patient, the correlation of skull intensities between CT and MR was investigated, the discriminatory power of MRI in separating air from bone was evaluated, and the generated MRCT image volume was qualitatively evaluated. Our analyses showed that one MRI volume was not sufficient to separate all tissue types, and T2-weighted images was more sensitive to bone density variation compared to other MRI image types. The short echo UTE image showed significant improvement in contrasting air versus bone, but could not completely separate air from bone without false labeling. Generated MRCT and CT images showed similar contrast between bone and soft/solid tissues. These results demonstrate the potential of the presented method to generate synthetic CT images to support the workflow of radiation oncology treatment planning and image guidance.

  10. Clinical predictors of abnormal head computed tomography scan in patients who are conscious after head injury

    Science.gov (United States)

    Mishra, Rakesh Kumar; Munivenkatappa, Ashok; Prathyusha, Vasuki; Shukla, Dhaval P.; Devi, Bhagavatula Indira

    2017-01-01

    Background: Indication of a head computed tomography (CT) scan in a patient who remains conscious after head injury is controversial. We aimed to determine the clinical features that are most likely to be associated with abnormal CT scan in patients with a history of head injury, and who are conscious at the time of presentation to casualty. Materials and Methods: This is a prospective observation study of patients presented to casualty with history of head injury, and who were conscious, i.e., Glasgow Coma Scale (GCS) 15 at the time of evaluation. All patients underwent head CT scan. The CT scan was reported as abnormal if it showed any pathology ascribed to trauma. The following variables were used: age, gender, mode of injury (road traffic accident, fall, assault, and others), duration since injury, and history of transient loss of consciousness, headache, vomiting, ear/nose bleeding, and seizures. Logistic regression analysis was used to identify the clinical features that predicted an abnormal CT scan. Results: During the observation period, a total of 1629 patients with head injury were evaluated, out of which 453 were in GCS 15. Abnormal CT scan was present in 195 (43%) patients. Among all the variables, the following were found significantly associated with abnormal CT scan: duration since injury (>12 h) P < 0.001; vomiting odds, ratio (OR) 1.89 (1.23, 2.80), P < 0.001; and presence of any symptom, OR 2.36 (1.52, 3.71), P < 0.001. Conclusion: A patient with GCS 15 presenting after 12 hours of injury with vomiting or combination of symptoms has a significant risk of abnormal head CT scan.

  11. Clinical predictors of abnormal head computed tomography scan in patients who are conscious after head injury

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Mishra

    2017-01-01

    Full Text Available Background: Indication of a head computed tomography (CT scan in a patient who remains conscious after head injury is controversial. We aimed to determine the clinical features that are most likely to be associated with abnormal CT scan in patients with a history of head injury, and who are conscious at the time of presentation to casualty. Materials and Methods: This is a prospective observation study of patients presented to casualty with history of head injury, and who were conscious, i.e., Glasgow Coma Scale (GCS 15 at the time of evaluation. All patients underwent head CT scan. The CT scan was reported as abnormal if it showed any pathology ascribed to trauma. The following variables were used: age, gender, mode of injury (road traffic accident, fall, assault, and others, duration since injury, and history of transient loss of consciousness, headache, vomiting, ear/nose bleeding, and seizures. Logistic regression analysis was used to identify the clinical features that predicted an abnormal CT scan. Results: During the observation period, a total of 1629 patients with head injury were evaluated, out of which 453 were in GCS 15. Abnormal CT scan was present in 195 (43% patients. Among all the variables, the following were found significantly associated with abnormal CT scan: duration since injury (>12 h P< 0.001; vomiting odds, ratio (OR 1.89 (1.23, 2.80, P< 0.001; and presence of any symptom, OR 2.36 (1.52, 3.71, P< 0.001. Conclusion: A patient with GCS 15 presenting after 12 hours of injury with vomiting or combination of symptoms has a significant risk of abnormal head CT scan.

  12. Cranial computed tomography scan findings in head trauma patients in Enugu, Nigeria

    OpenAIRE

    Ohaegbulam, Samuel C; Wilfred C Mezue; Ndubuisi, Chika A.; Erechukwu, Uwadiegwu A.; Ani, Chinenye O.

    2011-01-01

    Background: The choice of radiological investigations in head trauma in Africa is influenced by factors such as cost. Some patients who require computed tomography (CT) scan elsewhere are either managed blindly or do not present for it at the appropriate time. This paper evaluates the CT scan findings as they are obtained in cases of head trauma in a region of Nigeria. Methods: Prospectively recorded data of all head injury patients who presented for CT scan between January 2009 and April 201...

  13. Interpretation of head CT scans in the emergency department by fellows versus general staff non-neuroradiologists: a closer look at the effectiveness of a quality control program.

    Science.gov (United States)

    Le, Alexander H; Licurse, Adam; Catanzano, Tara M

    2007-10-01

    between the groups. The overall relatively low discrepant rate between fellowship trainees and generalist staffs, as well as the negligible change in clinical management, suggests little utility in over-reads of head CT scans by the neuroradiology service as part of a year-round quality control program. However, because of a relative high discrepant rate in the early months of fellowship training (>5%) in our study, it may be wise to implement a quality assurance program in the first few months to improve patient care. Increasing over-reading rate may reduce false negative rate, as the overall false positive rate is relatively low (<0.5%).

  14. Clinical Observation on Effect of Clearing the Governor Vessel and Refreshing the Mind Needling on Head SPECT and CT Scanning of Kids with Cerebral Palsy

    Institute of Scientific and Technical Information of China (English)

    刘振寰; 祁岩超; 潘佩光; 马美美; 钱旭光; 符文杰; 张宏雁

    2007-01-01

    目的:探讨针灸在脑瘫康复中的脑功能代偿作用.方法:100例脑瘫患儿随机分为治疗组(50例)和对照组(50例),治疗组采用通督补肾组穴:督脉穴13针配伍涌泉、阳陵泉、足三里、三阴交.和醒神头针(神庭透百会,百会透脑户和四神聪).配合康复训练.对照组单纯用康复训练.观察两组临床疗效以及头颅CT、SPECT病变恢复情况.结果:治疗组总有效率为84%,显著高于对照组总有效率的52%.治疗后发育商(DQ)治疗显著组高于对照组(P<0.01).头颅CT脑发育不良,脑萎缩的好转率和头颅SPECT脑神经元代谢功能恢复正常率,治疗组高于对照组(P<0.01)结论:针灸能促进脑功能的代偿作用.%To investigate the brain functional compensation of acupuncture in cerebral palsy rehabilitation. Method: All 100 cerebral palsy kids were randomized into a treatment group (50 cases) and a control group (50 cases). For cases in the treatment group,points of connecting the Governor Vessels and tonifying the kidney were selected: 13 points of the Governor Vessel, Yongquan (Kid 1), Yanglingquan (GB 34), Zusanli (ST 36) and Sanyinjiao (SP 6), and points of refreshing the mind were also selected: puncturing Shenting (GV 24) toward Baihui (GV 20) and puncturing Baihui (GV 20) toward Naohu (GV 17) and Sishencong (Ex-HN 1). In addition, rehabilitation training was also combined. For cases in the control group,rehabilitation training alone was adopted. Then the clinical effect and improvement through head CT scanning and SPECT were observed. Result: The total effective rate of the treatment group was 84%, significantly higher than 52% of the control group. After treatment, the DQ in the treatment group was significantly higher than the control group (P<0.01). Also, the improvement rate of brain maldevelopment and brain atrophy showed by CT scan and restoration rate of brain neuron metabolic function in the treatment group were higher than the control group

  15. CT scan findings in mild head trauma: a series of 2,000 patients Achados tomográficos no trauma cranioencefálico leve: análise de 2000 casos

    Directory of Open Access Journals (Sweden)

    Kelly C. Bordignon

    2002-06-01

    Full Text Available The present study describes the cranial computed tomography (CT scan findings of 2,000 cases of mild head trauma (HT in Curitiba, Southern Brazil. The mean age of the entire series was 30.8 ±19 years. The overall male to female ratio was 2:1. The most common causes of head injury were interpersonal aggression (17.9%, falls (17.4%, automobile accidents (16.2%, falls to the ground (13.1% and pedestrian injuries (13 %. Alcohol intoxication was associated with HT in 158 cases (7.9%. A normal CT scan was seen in 60.75% (1215 and an abnormal CT scan in 39.25% (785 of patients. Out of 785 abnormal CT scan, 518(65.9% lesions were related to HT. The most common CT scan HT related findings were: soft tissue swelling (8.9 %, skull fractures (4.3 %, intracranial and subgaleal hematomas (3.4% and 2.4 %, brain swelling (2 % and brain contusion (1.2%. Out of 785 abnormal CT scans, 267 (34.1% lesions were not related to head trauma. Incidental CT scan findings included brain atrophy (5.9%, one calcification (5.2% several calcifications (2.4% (probably neurocysticercosis in most cases, ischemic infarct (1.9% and leukoaraiosis (1.3%. These findings showed the importance of CT scan examination in mild head injuries. Further studies to identify mild HT patients at higher risk of significant brain injury are warranted in order to optimize its use.São descritos os achados de tomografia computadorizada craniana (TC de 2000 casos de trauma cranio-encefálico (TCE leve em Curitiba, Paraná. A idade média de toda série de pacientes foi 30,8 ± 19 anos. A razão homem/mulher foi 2:1. A causas mais comuns de TCE foram agressão interpessoal (17,9%, quedas de nível (17,4%, acidentes automobilísticos (16,2%, queda ao solo (13,1% e atropelamento (13%. Intoxicação por álcool foi um importante fator associado ao TCE e esteve presente em 158 casos (7,9% de 2000 pacientes. Uma TC normal ocorreu em 60,75% (1215 e uma TC anormal em 39,25% (785 dos pacientes. Das 785 TC

  16. The reproducibility of a HeadFix relocatable fixation system: analysis using the stereotactic coordinates of bilateral incus and the top of the crista galli obtained from a serial CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Kunieda, Etsuo; Oku, Yohei; Fukada, Junichi; Kawaguchi, Osamu; Kubo, Atsushi [Department of Radiology, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582 (Japan); Shiba, Hideyuki [Department of Dentistry and Oral Surgery, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582 (Japan); Takeda, Atsuya [Department of Radiation Oncology, Ofuna Chuo Hospital, 6-2-24 Ofuna, Kamakura City, Kanagawa 247-0056 (Japan)], E-mail: kunieda-mi@umin.ac.jp

    2009-05-21

    We analysed the repositioning accuracy of bite-plate fixations from serial QA-CT (quality-assurance CT) taken during the course of stereotactic radiotherapy. A total of 72 series of CT examinations from 15 consecutive patients, who underwent stereotactic radiotherapy for various intracranial tumours, were examined. Three or four CT scans were obtained for the purpose of QA for the right and left incus, as well as the crista galli. The stereotactic coordinates of the centres of the incus and the top of the crista galli were semi-automatically obtained for each QA-CT scan. Positional displacements for these anatomical reference points and the centre of the points were obtained. The mean displacements for these points in the 3D directions ranged from -0.10 to 0.08 mm (standard deviations: 0.44-0.94). The absolute positional displacement ranged from 0.93 to 1.09 mm (standard deviations: 0.52-0.88 mm). The rotations of the head were 0.49 {+-} 0.36 deg. Our 3D measurement technique using anatomical landmarks revealed excellent stability of the mouthpiece fixation system in terms of translational and rotational displacements. This technique can also be used as a QA method for other fixation devices. (note)

  17. Comparison of image quality between axial and spiral scan mode in routine head CT%常规头部CT螺旋扫描与轴扫描模式的影像质量对照

    Institute of Scientific and Technical Information of China (English)

    傅强; 刘晓菲; 于虹; 徐克

    2012-01-01

    目的 通过头部CT螺旋扫描和轴扫描两种不同扫描模式的影像质量对照,探讨常规头部CT采用螺旋扫描模式取代轴扫描模式的可行性.方法 40例患者,其中男性24例,女性16例;年龄18 ~ 74岁,平均年龄46岁.分别接受头部CT螺旋扫描和轴扫描两种不同模式扫描,轴扫描参数:140 kV、170 mA用于颅底部;120 kV、150 mA用于颅脑部,每周2s.螺旋扫描参数:120 kV,150 mA,每周0.6 s.扫描剂量直接取自设备剂量指示值(CTDI和DLP).影像质量分别由2位专家采用双盲法,对头部CT的颅底、脑灰-白质层面及全部影像逐层进行CT值测量评估.结果 常规头部CT螺旋扫描模式较轴扫描模式可有效去除颅底部伪影,并能减少扫描时间和扫描剂量(轴扫描模式与螺旋扫描模式对比,CTDI 55.43 mGy/37.80 mGy;DLP 662.10 mGy· cm/498.28 mGy· cm;扫描时间12.0 s/7.2 s)(P< 0.001).结论 常规头部CT螺旋扫描模式的影像质量完全可与轴扫描模式相媲美,并可取代轴扫描模式.同时常规头部CT螺旋扫描模式还具有可减少扫描时间和辐射剂量,并可进行影像的二维和三维后处理,有利于提高微小病灶正确诊断率的优越性.%Objective To assess the feasibility of replacing axial CT scan mode with spiral CT scan mode in routine head CT through comparing the image quality between spiral and routine axial (sequential) acquired head CT. Methods A total of 40 cases were enrolled, male 24, female 16; aged 18 - 74 years old, mean age 46 years old. They were performed spiral scan and axial scan, respectively. Scan parameter axial mode were 140 kV, 170 mA for petrou bone, and 120 kV, 150 mA for brain, scan time 2.0 s/rol; and spiral mode were 120 kV, 150 mA, scan time 0.6 s/rol. Radiation dose were measured directly from the CT scan indicated computed tomography dose index (CTDI) and dose-length product (DLP). The image quality at the level of the posterior fossa and grey -white matter

  18. Efficacy of breast shielding during CT of the head

    Energy Technology Data Exchange (ETDEWEB)

    Brnic, Z.; Hebrang, A.; Anic, P. [Department of Diagnostic and Interventional Radiology, University Hospital Merkur, Zajceva 19, 10000, Zagreb (Croatia); Vekic, B. [' ' Ruder Boskovic' ' Research Institute, 10000, Zagreb (Croatia)

    2003-11-01

    In light of increasing frequency of CT examinations in the past decades, the aims of this prospective study were to investigate scatter radiation breast exposure in head CT and its dependence upon body constitution, and to assess the efficacy of lead shielding as a means of breast dose reduction. In 49 women referred to head CT for objective medical reasons one breast was covered with lead apron during CT scanning. Radiation doses were measured by use of thermoluminescent dosimeters, at skin of both breasts and over the apron. The doses were then compared as well as correlated to body mass index and meatus acusticus externus-to-dosimeter distance, respectively. Average exposure at the skin of the unshielded breast was 0.28 mGy (range 0.15-0.41 mGy), compared with 0.13 mGy (range 0.05-0.29 mGy) at the shielded breast. The doses showed a mean reduction by 57% due to lead shielding. At least half of breast exposure was imparted to the breast from outside, whereas the remainder results from internal scatter. The higher the body mass index, the higher the percentage of internal scatter in total breast dose. Although the level of scatter radiation to the breast is generally low during head CT examination, the use of lead cover enables recognizable further reduction of the exposure, and is recommended as a feasible and effective procedure of breast protection during CT of the head. (orig.)

  19. Evaluation strategies in CT scanning

    DEFF Research Database (Denmark)

    uncertainty. This investigation includes measurements of two industrial items, an aluminum pipe connector and a plastic toggle, a hearing aid component. These are measured using a commercial CT scanner. Traceability is transferred using tactile and optical coordinate measuring machines, which are used...

  20. The feasibility of endoscopy-CT image registration in the head and neck without prospective endoscope tracking

    National Research Council Canada - National Science Library

    W Scott Ingram; Jinzhong Yang; Beth M Beadle; Richard Wendt III; Arvind Rao; Xin A Wang; Laurence E Court

    2017-01-01

    Purpose Endoscopic examinations are frequently-used procedures for patients with head and neck cancer undergoing radiotherapy, but radiation treatment plans are created on computed tomography (CT) scans...

  1. Clinical Symptoms of Minor Head Trauma and Abnormal Computed Tomography Scan

    Directory of Open Access Journals (Sweden)

    Maghsoudi

    2015-11-01

    Full Text Available Background Minor head trauma accounts for 70% to 90% of all head traumas. Previous studies stated that minor head traumas were associated with 7% - 20% significant abnormal findings in brain computed tomography (CT-scans. Objectives The aim of this study was to reevaluate clinical criteria of taking brain CT scan in patients who suffered from minor head trauma. Patients and Methods We enrolled 680 patients presented to an academic trauma hospital with minor head trauma in a prospective manner. All participants underwent brain CT scan if they met the inclusion criteria and the results of scans were compared with clinical examination finding. Results Loss of consciousness (GCS drop or amnesia was markedly associated with abnormal brain CT scan (P < 0.05. Interestingly, we found 7 patients with normal clinical examination but significant abnormal brain CT scan. Conclusions According to the results of our study, we recommend that all patients with minor head trauma underwent brain CT scan in order not to miss any life-threatening head injuries.

  2. CT Perfusion of the Head

    Science.gov (United States)

    ... You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras ... and surgical biopsy. No radiation remains in a patient's body after a CT ... side effects. Risks There is always a slight chance of cancer ...

  3. Contextual Analysis of CT Scanned Pig Carcasses

    DEFF Research Database (Denmark)

    Lyckegaard, Allan; Larsen, Rasmus; Christensen, Lars Bager;

    2006-01-01

    Knowledge of the weight of tissue types in pig carcasses is generally only available after manual dissection. The use of computed tomography (CT) has demonstrated to be a promising approach to gain knowledge on the lean meat weight (Romvari, 2005), but less effort has been put into gaining...... knowledge about the weight of other tissue types from CT. Knowing the weight of individual tissue types will directly give access to other measures such as the weight of the carcass and the Lean Meat Percentage (LMP). Until now, most analyses of CT scans have been based on the Hounsfield spectra that does...... not consider the spatial context in CT scan. Applying contextual methods from the field of image analysis we hope to make a virtual dissection of pig carcasses....

  4. Incidental Findings on CT Scans in the Emergency Department

    Directory of Open Access Journals (Sweden)

    Ryan J. Thompson

    2011-01-01

    Full Text Available Objectives. Incidental findings on computed tomography (CT scans are common. We sought to examine rates of findings and disclosure among discharged patients who received a CT scan in the ED. Methods. Retrospective chart review (Aug-Oct 2009 of 600 patients age 18 and older discharged home from an urban Level 1 trauma center. CT reports were used to identify incidental findings and discharge paperwork was used to determine whether the patient was informed of these findings. Results. There were 682 CT scans among 600 patients: 199 Abdomen & Pelvis, 405 Head, and 78 Thorax. A total of 348 incidental findings were documented in 228/682 (33.4% of the scans, of which 34 (9.8% were reported to patients in discharge paperwork. Patients with 1 incidental finding were less likely to receive disclosure than patients with 2 or more (=.010. Patients age <60 were less likely to have incidental findings (<.001. There was no significant disclosure or incidental finding difference by gender. Conclusions. While previous research suggests that CT incidental findings are often benign, reporting to patients is recommended but this is rarely happening.

  5. Artifacts and pitfalls of high-resolution CT scans.

    Science.gov (United States)

    Hahn, F J; Chu, W K; Anderson, J C; Dobry, C A

    1985-01-01

    Artifacts on CT images have been observed since the introduction of CT scanners. Some artifacts have been corrected with the improvement of technology and better understanding of the image formation and reconstruction algorithms. Some artifacts, however, are still observable in state-of-the-art high-resolution scans. Many investigations on CT artifacts have been reported. Some artifacts are obvious and some are similar to patterns commonly associated with pathological conditions. The present report summarizes some of the causes of artifacts and presents some artifacts that mimic pathology on clinical scans of the head and spine. It is the intention of this report to bring these artifacts and potential pitfalls to the attention of the radiologists so that misinterpretation can be avoided.

  6. CT scan of bacterial and aseptic meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Takemoto, Kazumasa; Saiwai, Shigeo; Tamaoka, Koichi (Kobe Central Municipal Hospital (Japan))

    1983-01-01

    CT scans of the patients with aseptic and bacterial meningitis were reviewed and compared to previous reports. In aseptic meningitis, no abnormal CT findings were observed. In bacterial meningitis, CT findings were ventricular dilatation, subdural fluid collection, parenchymal low density, intracerebral hematoma and meningeal enhancement after contrast injection. Three patients among 48 suffered from status epileptics during the course of the illness. All of the 3 patients developed parenchymal inhomogeneous low density and progressive ventricular dilatation which did not improve after ventricular peritoneal shunt surgery. We believe that these changes are most likely due to hypoxic hypoxemia during epileptic seizure and meningitis itself seems to play a little role.

  7. Prognostic role of metabolic parameters of {sup 18}F-FDG PET-CT scan performed during radiation therapy in locally advanced head and neck squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Min, Myo; Forstner, Dion [Liverpool Hospital, Cancer Therapy Centre, Liverpool, NSW (Australia); University of New South Wales, Sydney, NSW (Australia); Ingham Institute of Applied Medical Research, Liverpool, NSW (Australia); Lin, Peter; Shon, Ivan Ho; Lin, Michael [University of New South Wales, Sydney, NSW (Australia); Liverpool Hospital, Department of Nuclear Medicine and Positron Emission Tomography, Liverpool, NSW (Australia); University of Western Sydney, Sydney, NSW (Australia); Lee, Mark T. [Liverpool Hospital, Cancer Therapy Centre, Liverpool, NSW (Australia); University of New South Wales, Sydney, NSW (Australia); Bray, Victoria; Fowler, Allan [Liverpool Hospital, Cancer Therapy Centre, Liverpool, NSW (Australia); Chicco, Andrew [Liverpool Hospital, Department of Nuclear Medicine and Positron Emission Tomography, Liverpool, NSW (Australia); Tieu, Minh Thi [Calvary Mater Newcastle, Department of Radiation Oncology, Newcastle, NSW (Australia); University of Newcastle, Newcastle, NSW (Australia)

    2015-12-15

    To evaluate the prognostic value of {sup 18}F-FDG PET-CT performed in the third week (iPET) of definitive radiation therapy (RT) in patients with newly diagnosed locally advanced mucosal primary head and neck squamous-cell-carcinoma (MPHNSCC). Seventy-two patients with MPHNSCC treated with radical RT underwent staging PET-CT and iPET. The maximum standardised uptake value (SUV{sub max}), metabolic tumour volume (MTV) and total lesional glycolysis (TLG) of primary tumour (PT) and index node (IN) [defined as lymph node(s) with highest TLG] were analysed, and results were correlated with loco-regional recurrence-free survival (LRFS), disease-free survival (DFS), metastatic failure-free survival(MFFS) and overall survival (OS), using Kaplan-Meier analysis. Optimal cutoffs (OC) were derived from receiver operating characteristic curves: SUV{sub max-PT} = 4.25 g/mL, MTV{sub PT} = 3.3 cm{sup 3}, TLG{sub PT} = 9.4 g, for PT, and SUV{sub max-IN} = 4.05 g/mL, MTV{sub IN} = 1.85 cm{sup 3} and TLG{sub IN} = 7.95 g for IN. Low metabolic values in iPET for PT below OC were associated with statistically significant better LRFS and DFS. TLG was the best predictor of outcome with 2-year LRFS of 92.7 % vs. 71.1 % [p = 0.005, compared with SUV{sub max} (p = 0.03) and MTV (p = 0.022)], DFS of 85.9 % vs. 60.8 % [p = 0.005, compared with SUV{sub max} (p = 0.025) and MTV (p = 0.018)], MFFS of 85.9 % vs. 83.7 % [p = 0.488, compared with SUV{sub max} (p = 0.52) and MTV (p = 0.436)], and OS of 81.1 % vs. 75.0 % [p = 0.279, compared with SUV{sub max} (p = 0.345) and MTV (p = 0.512)]. There were no significant associations between the percentage reduction of primary tumour metabolic parameters and outcomes. In patients with nodal disease, metabolic parameters below OC (for both PT and IN) were significantly associated with all oncological outcomes, while TLG was again the best predictor: LRFS of 84.0 % vs. 55.3 % (p = 0.017), DFS of 79.4 % vs. 38.6 % (p = 0.001), MFFS 86.4 % vs. 68.2 % (p = 0

  8. CT analysis of missile head injury

    Energy Technology Data Exchange (ETDEWEB)

    Besenski, N. [Dept. of Radiology, Zagreb Univ. Hospital Rebro (Croatia); Jadro-Santel, D. [Dept. of Neuropathology, Zagreb Univ. Hospital Rebro (Croatia); Jelavic-Koic, F. [Dept. of Radiology, General Hospital Sveti Duh, Zagreb (Croatia); Pavic, D. [Dept. of Neuropathology, Zagreb Univ. Hospital Rebro (Croatia); Mikulic, D. [Zagreb School of Medicine (Croatia); Glavina, K. [Dept. of Radiology, Clinical Hospital, Osijek (Croatia); Maskovic, J. [Dept. of Radiology, Clinical Hospital, Split (Croatia)

    1995-04-01

    Between August 1991 and December 1992, CT was performed in 154 patients who had suffered missile head injury during the war in the Republic of Croatia. In 54% CT was performed 1-24 h after injury, and in 27% follow-up CT was also obtained. The wounds were penetrating, tangential or perforating (45%, 34% and 21%, respectively). Haemorrhage was the most frequent lesion in the brain (84%). Follow-up CT evolution of haemorrhage, oedema, cerebritis, abscess, secondary vascular lesions, necrosis, encephalomalacia and hydrocephalus. The most dynamic changes occurred 7-14 days after injury. In 14% of cases, deep cerebral lesions were found in the corpus callosum, septum pellucidum periventricular region and pons, although bone and shell fragments were in a different part of the brain parenchyma. Such lesions were found in penetrating injuries only. CT proved very useful for assessing the extent and type of lesions. Although different mechanisms of brain damage in missile head injury are known, here they are, to the best of our knowledge, shown for the first time by CT. (orig.)

  9. Evolving brain lesions in the follow-up CT scans 12 h after traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    Muhammad Sohail Umerani; Asad Abbas; Saqib Kamran Bakhshi; Ujala Muhammad Qasim; Salman Sharif

    2016-01-01

    Objective: To establish the frequency of evolution in CT appearance from an initial scan to a subsequent scan within 12 h and the prognostic significance of such deterioration. Methods: All patients who presented to Department of Neurosurgery, Liaquat National Hospital and Medical College with traumatic brain injury and received their CT scan within the first 4 h of injury were included in the study. Indications for repeat CT scan were: any deterioration in neurological status after the initial scan, potentially deterio-rating lesion on initial scan with or without worsening neurology, worsening neurological status after the initial CT scan findings, or no neurological improvement after initial management in patients with normal CT scan with significant head injury. This compiled with the data of 107 patients. Results: There were 67 males and 40 females. The cause of trauma of the 70%patients was road traffic accident. In 11 patients, the lesion evolved towards resorption while 32 patients had no significant changes in the subsequent CT scan. Sixty four patients showed an increase in the size of the lesion and 65.6%of them were required surgical intervention subsequently. Conclusions: In case where the initial CT scan performed within 4 h of significant head injury was not correlated with the patient's neurology, it should be repeated within 12 h.

  10. Perfusion CT of head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Razek, Ahmed Abdel Khalek Abdel, E-mail: arazek@mans.edu.eg; Tawfik, Ahmed Mohamed, E-mail: ahm_m_tawfik@hotmail.com; Elsorogy, Lamiaa Galal Ali, E-mail: lamia2elsorogy@hotmail.com; Soliman, Nermin Yehia, E-mail: nermin_eid@hotmail.com

    2014-03-15

    We aim to review the technique and clinical applications of perfusion CT (PCT) of head and neck cancer. The clinical value of PCT in the head and neck includes detection of head and neck squamous cell carcinoma (HNSCC) as it allows differentiation of HNSCC from normal muscles, demarcation of tumor boundaries and tumor local extension, evaluation of metastatic cervical lymph nodes as well as determination of the viable tumor portions as target for imaging-guided biopsy. PCT has been used for prediction of treatment outcome, differentiation between post-therapeutic changes and tumor recurrence as well as monitoring patient after radiotherapy and/or chemotherapy. PCT has a role in cervical lymphoma as it may help in detection of response to chemotherapy and early diagnosis of relapsing tumors.

  11. PET/CT imaging in head and neck tumors; PET-CT-Bildgebung bei Kopf-Hals-Tumoren

    Energy Technology Data Exchange (ETDEWEB)

    Roedel, R.; Palmedo, H.; Reichmann, K.; Reinhardt, M.J.; Biersack, H.J. [Universitaetsklinikum Bonn, Klinik und Poliklinik fuer Nuklearmedizin (Germany); Straehler-Pohl, H.J. [Universitaetsklinikum Bonn, Klinik und Poliklinik fuer Hals-, Nasen- und Ohrenheilkunde (Germany); Jaeger, U. [Universitaetsklinikum Bonn, Radiologische Klinik (Germany)

    2004-11-01

    To evaluate the usefulness of combined PET/CT examinations for detection of malignant tumors and their metastases in head and neck oncology. 51 patients received whole body scans on a dual modality PET/CT system. CT was performed without i.v. contrast. The results were compared concerning the diagnostic impact of native CT scan on FDG-PET images and the additional value of fused imaging. From 153 lesions were 97 classified as malignant on CT and 136 on FDG/PET images, as suspicious for malignancy in 33 on CT and 7 on FDG-PET and as benign in 23 on CT and 10 on FDG-PET. With combined PET/CT all primary and recurrent tumors could be found, the detection rate in patients with unknown primary tumors was 45%. Compared to PET or CT alone the sensitivity, specifity and accuracy could be significantly improved by means of combined PET/CT. Fused PET/CT imaging with [F18]-FDG and native CT-scanning enables accurate diagnosis in 93% of lesions and 90% of patients with head and neck oncology. (orig.) [German] Die Bestimmung der Wertigkeit der kombinierten PET-CT-Untersuchung zum Nachweis maligner Kopf-Hals-Tumoren und ihrer Metastasen. Bei 51 Patienten wurden Ganzkoerperuntersuchungen mit dem kombiniertem PET-CT-System durchgefuehrt. Die CT erfolgte ohne i.v. Kontrastmittelgabe. Die Ergebnisse wurden in ihrer diagnostischen Aussage einerseits getrennt fuer native CT- und FDG-PET-Bildgebung und andererseits fuer das fusionierte Bild verglichen. Von 153 Laesionen wurden 97 im CT und 136 im FDG-PET als maligne, 33 im CT und 7 im FDG-PET als malignitaetsverdaechtig, 23 im CT und 10 in der FDG-PET als benigne beurteilt. Die Anzahl der konkordanten Ergebnisse betrug 94 (61%), die der diskordanten 59 (39 %). Mit der PET-CT konnten alle Primaertumoren und Rezidive entdeckt werden, die Nachweisrate eines unbekannten Primaertumors betrug 45%. Im Vergleich zur alleinigen PET- oder CT-Untersuchung erhoehen sich bei der kombinierten PET-CT Sensitivitaet, Spezifitaet sowie die

  12. CT scan range estimation using multiple body parts detection: let PACS learn the CT image content.

    Science.gov (United States)

    Wang, Chunliang; Lundström, Claes

    2016-02-01

    The aim of this study was to develop an efficient CT scan range estimation method that is based on the analysis of image data itself instead of metadata analysis. This makes it possible to quantitatively compare the scan range of two studies. In our study, 3D stacks are first projected to 2D coronal images via a ray casting-like process. Trained 2D body part classifiers are then used to recognize different body parts in the projected image. The detected candidate regions go into a structure grouping process to eliminate false-positive detections. Finally, the scale and position of the patient relative to the projected figure are estimated based on the detected body parts via a structural voting. The start and end lines of the CT scan are projected to a standard human figure. The position readout is normalized so that the bottom of the feet represents 0.0, and the top of the head is 1.0. Classifiers for 18 body parts were trained using 184 CT scans. The final application was tested on 136 randomly selected heterogeneous CT scans. Ground truth was generated by asking two human observers to mark the start and end positions of each scan on the standard human figure. When compared with the human observers, the mean absolute error of the proposed method is 1.2% (max: 3.5%) and 1.6% (max: 5.4%) for the start and end positions, respectively. We proposed a scan range estimation method using multiple body parts detection and relative structure position analysis. In our preliminary tests, the proposed method delivered promising results.

  13. Clinical utility and cost analysis of routine postoperative head CT in elective aneurysm clippings.

    Science.gov (United States)

    Zygourakis, Corinna C; Winkler, Ethan; Pitts, Lawrence; Hannegan, Lisa; Franc, Benjamin; Lawton, Michael T

    2017-02-01

    OBJECTIVE Postoperative head CT scanning is performed routinely at the authors' institution on all neurosurgical patients after elective aneurysm clippings. The goal of this study was to determine how often these scans influence medical management and to quantify the associated imaging costs. METHODS The authors reviewed the medical records and accounting database of 304 patients who underwent elective (i.e., nonruptured) aneurysm clipping performed by 1 surgeon (M.T.L.) from 2010 to 2014 at the University of California, San Francisco. Specifically, the total number of postoperative head CT scans, radiographic findings, and the effect of these studies on patient management were determined. The authors obtained the total hospital costs for these patients, including the cost of imaging studies, from the hospital accounting database. RESULTS Overall, postoperative CT findings influenced clinical management in 3.6% of cases; specifically, they led to permissive hypertension in 4 patients for possible ischemia, administration of mannitol for edema and high-flow oxygen for pneumocephalus in 2 patients each, seizure prophylaxis in 1 patient, Plavix readjustment in 1 patient, and return to the operating room for an asymptomatic epidural hematoma evacuation in 1 patient. When patients were stratified on the basis of postoperative neurological examination, findings on CT scans altered management in 1.1%, 4.8%, and 9.0% of patients with no new neurological deficits, a nonfocal examination, and focal deficits, respectively. The mean total hospital cost for treating patients who undergo elective aneurysm clipping was $72,227 (± $53,966) (all values are US dollars), and the cost of obtaining a noncontrast head CT scan was $292. Neurologically intact patients required 99 head CT scans, at a cost of $28,908, to obtain 1 head CT scan that influenced medical management. In contrast, patients with a focal neurological deficit required only 11 head CT scans, at a cost of $3212, to

  14. CT scan correlates of gesture recognition.

    Science.gov (United States)

    Ferro, J M; Martins, I P; Mariano, G; Caldas, A C

    1983-10-01

    The ability to recognise gestures was studied in 65 left-hemispheric stroke patients whose lesions were located by CT scan. In the acute stage (first month) frontal lobe and basal ganglia were frequently involved in patients showing inability to recognise gestures. In the later (third to fourth month) and chronic stages (greater than 6 months) parietal lobe involvement was important; lesions causing gesture recognition impairment were larger, had more extensive and frequent parietal involvement and produced less temporal lobe damage than those causing aural comprehension defects. These findings are discussed in the light of recent models of cerebral localisation of complex functions.

  15. Acquired tracheomalacia: detection by expiratory CT scan.

    Science.gov (United States)

    Aquino, S L; Shepard, J A; Ginns, L C; Moore, R H; Halpern, E; Grillo, H C; McLoud, T C

    2001-01-01

    The purpose of this work was to determine whether cross-sectional area and coronal and sagittal diameter measurements of the trachea between inspiration and end-expiration on CT are significantly different between patients with acquired tracheomalacia and those without this condition. Inspiratory and end-expiratory CT scans of the trachea of 23 normal patients and 10 patients with acquired tracheomalacia were analyzed. Percent changes in cross-sectional area, coronal, and sagittal diameters were calculated. For patients with tracheomalacia, mean percent changes in the upper and middle trachea between inspiration and expiration were 49 and 44%; mean changes in the coronal and sagittal diameters in the upper and middle tracheal were 4 and 10% and 39 and 54%, respectively. Control group mean percent changes in the upper and middle tracheal area were 12 and 14%, respectively, and mean changes in the coronal and sagittal diameters in the upper and middle trachea were 4 and 4% and 11 and 13%, respectively. Significant differences were calculated for changes in cross-sectional area and sagittal diameter between groups (p 18% change in the upper trachea and 28% change in the midtrachea between inspiration and expiration were observed; the probability of tracheomalacia was 89-100%. The probability of tracheomalacia was > 89%, especially if the change in sagittal diameter was > 28%. By measuring changes in tracheal cross-sectional area and sagittal diameters between inspiratory and end-expiratory CT, a significant difference can be identified between normal patients and those with acquired tracheomalacia.

  16. Diagnosis of pituitary microadenomas by CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Sakoda, K.; Gen, M.; Yonezawa, M.; Ohta, M.; Matsumura, S. (Hiroshima Univ. (Japan). School of Medicine)

    1981-10-01

    The presence of pituitary microadenomas can be established by the detection of minor changes on polytomograms of the sella turcica. However, as this method is a procedure for detecting secondary changes due to adenoma, it is understandable that microadenomas which fail to present secondary changes cannot be picked up. From this point of view, we investigated the possibility detecting changes in the pituitary itself by means of CT. An axial scan of pituitary microadenomas by EMI-1010 showed that some of the PRL secreting adenomas and all of the GH secreting adenomas showed areas of high density, and that some of PRL secreting adenomas and all the ACTH secreting adenomas showed areas of low density at the site of the adenomas. On a coronal scan with GE/X2, the normal pituitary is highly enhanced, and an absorption coefficient of 70 - 80 is demonstrated, but on an axial scan the coefficient becomes 25 - 35 due to the partial-volume effect. On a coronal scan pituitary microadenomas are shown as hypodense-lucent or isodense as a normal pituitary. However, the absorption coefficient of the hypodense-lucent area was 50 - 60; this is not low, but is, rather, a high density. At present, it is our belief that it is most effective to use a coronal angle with a high-resolution scanner in the diagnosis of pituitary microadenomas.

  17. CT and MRI matching for radiotherapy planning in head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rasch, C.; Keus, R.; Touw, A.; Lebesque, J.; Van Herk, M. [Nederlands Kanker Inst. `Antoni van Leeuwenhoekhuis`, Amsterdam (Netherlands)

    1995-12-01

    The objective of this study was to evaluate the impact of matched CT and MRI information on target delineation in radiotherapy planning for head and neck tumors. MRI images of eight patients with head and neck cancer in supine position, not necessarily obtained in radiotherapy treatment position were matched to the CT scans made in radiotherapy position using automatic three-dimensional chamfer-matching of bony structures. Four independent observers delineated the Gross Tumor Volume (GTV) in CT scans and axial and sagittal MR scans. The GTV`s were compared, overlapping volumes and non-overlapping volumes between the different datasets and observers were determined. In all patients a good match of CT and MRI information was accomplished in the head region. The combined information provided a better visualisation of the GTV, oedema and normal tissues compared with CT or MRI alone. Determination of overlapping and non-overlapping volumes proved to be a valuable tool to measure uncertainties in the determination of the GTV. CT-MRI matching in patients with head and neck tumors is feasible and makes a more accurate irradiation with higher tumor doses and less normal tissue complications possible. Remaining uncertainties in the determination of the GTV can be quantified using the combined information of MRI and CT.

  18. Operation of the preclinical head scanner for proton CT

    Science.gov (United States)

    Sadrozinski, H. F.-W.; Geoghegan, T.; Harvey, E.; Johnson, R. P.; Plautz, T. E.; Zatserklyaniy, A.; Bashkirov, V.; Hurley, R. F.; Piersimoni, P.; Schulte, R. W.; Karbasi, P.; Schubert, K. E.; Schultze, B.; Giacometti, V.

    2016-09-01

    We report on the operation and performance tests of a preclinical head scanner developed for proton computed tomography (pCT). After extensive preclinical testing, pCT is intended to be employed in support of proton therapy treatment planning and pre-treatment verification in patients undergoing particle-beam therapy. In order to assess the performance of the scanner, we have performed CT scans with 200 MeV protons from both the synchrotron of the Loma Linda University Medical Center (LLUMC) and the cyclotron of the Northwestern Medicine Chicago Proton Center (NMCPC). The very high sustained rate of data acquisition, exceeding one million protons per second, allowed a full 360° scan to be completed in less than 7 min. The reconstruction of various phantoms verified accurate reconstruction of the proton relative stopping power (RSP) and the spatial resolution in a variety of materials. The dose for an image with better than 1% uncertainty in the RSP is found to be close to 1 mGy.

  19. Operation of the preclinical head scanner for proton CT

    Energy Technology Data Exchange (ETDEWEB)

    Sadrozinski, H.F.-W., E-mail: hartmut@ucsc.edu [SCIPP, U.C. Santa Cruz, Santa Cruz, CA 95064 (United States); Geoghegan, T.; Harvey, E.; Johnson, R.P.; Plautz, T.E.; Zatserklyaniy, A. [SCIPP, U.C. Santa Cruz, Santa Cruz, CA 95064 (United States); Bashkirov, V.; Hurley, R.F.; Piersimoni, P.; Schulte, R.W. [Division of Radiation Research, Loma Linda University, Loma Linda, CA 92354 (United States); Karbasi, P.; Schubert, K.E.; Schultze, B. [School of Engineering and Computer Science, Baylor University, Waco, TX 76798 (United States); Giacometti, V. [Center for Medical Radiation Physics, University of Wollongong, NSW (Australia)

    2016-09-21

    We report on the operation and performance tests of a preclinical head scanner developed for proton computed tomography (pCT). After extensive preclinical testing, pCT is intended to be employed in support of proton therapy treatment planning and pre-treatment verification in patients undergoing particle-beam therapy. In order to assess the performance of the scanner, we have performed CT scans with 200 MeV protons from both the synchrotron of the Loma Linda University Medical Center (LLUMC) and the cyclotron of the Northwestern Medicine Chicago Proton Center (NMCPC). The very high sustained rate of data acquisition, exceeding one million protons per second, allowed a full 360° scan to be completed in less than 7 min. The reconstruction of various phantoms verified accurate reconstruction of the proton relative stopping power (RSP) and the spatial resolution in a variety of materials. The dose for an image with better than 1% uncertainty in the RSP is found to be close to 1 mGy.

  20. High speed printing with polygon scan heads

    Science.gov (United States)

    Stutz, Glenn

    2016-03-01

    To reduce and in many cases eliminate the costs associated with high volume printing of consumer and industrial products, this paper investigates and validates the use of the new generation of high speed pulse on demand (POD) lasers in concert with high speed (HS) polygon scan heads (PSH). Associated costs include consumables such as printing ink and nozzles, provisioning labor, maintenance and repair expense as well as reduction of printing lines due to high through put. Targets that are applicable and investigated include direct printing on plastics, printing on paper/cardboard as well as printing on labels. Market segments would include consumer products (CPG), medical and pharmaceutical products, universal ID (UID), and industrial products. In regards to the POD lasers employed, the wavelengths include UV(355nm), Green (532nm) and IR (1064nm) operating within the repetition range of 180 to 250 KHz.

  1. A STUDY OF CORRELATION BETWEEN NASAL ENDOSCOPY AND CT SCAN IN CASES OF CHRONIC RHINOSINUSITIS

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2015-07-01

    Full Text Available BACKGROUND: The accurate diagnosis of Chronic Rhinosinusitis (CRS is still a challenge therefore, the American Academy of Otorhinolaryngology - Head and Neck Surgery (AAO - HNS 1 has met in a multidisciplinary encounter and formulated a consensus based on only clinical symptoms. The computed tomography (CT scan and the nasal endoscopy (NE were introduced to make an accurate diagnosis of CRS and verify the disease severity. AIM: The aim of this study is to make a correlation between nasal endoscopy and CT scan in cases of clinically diagnosed Chronic Rhinosinusitis patients. METHOD: A study was carried out on 90 patients at Jhalawar Medical College, Jhalawar (Raj. during Sept. 20 12 to Dec. 2014. Diagnostic Nasal Endoscopy and CT Scan PNS done in patients, suffering from Chronic Rhinosinusitis. As a classification instruments, Metson / Gliklich's classification was used to evaluate the tomographic diagnosis and the Stankiewicz / Chow' s classification to evaluate the endoscopic diagnosis of Chronic Rhinosinusitis. RESULTS: Our study showed high specificity of endoscopy in comparison to CT scan though CT scan results are more sensitive. CONCLUSION: Endoscopy can confirm a Chronic Rhinosi nusitis diagnosis, but cannot rule it out, and that CT should be performed in cases of suspected CRS even if mucopurulence is not noted on endoscopy. The CT scan and the nasal endoscopy making easier the treatment planning and the disease resolution.

  2. Segmentation of anatomical structures in chest CT scans

    NARCIS (Netherlands)

    van Rikxoort, E.M.

    2009-01-01

    In this thesis, methods are described for the automatic segmentation of anatomical structures from chest CT scans. First, a method to segment the lungs from chest CT scans is presented. Standard lung segmentation algorithms rely on large attenuation differences between the lungs and the surrounding

  3. Automatic segmentation of pulmonary segments from volumetric chest CT scans.

    NARCIS (Netherlands)

    Rikxoort, E.M. van; Hoop, B. de; Vorst, S. van de; Prokop, M.; Ginneken, B. van

    2009-01-01

    Automated extraction of pulmonary anatomy provides a foundation for computerized analysis of computed tomography (CT) scans of the chest. A completely automatic method is presented to segment the lungs, lobes and pulmonary segments from volumetric CT chest scans. The method starts with lung segmenta

  4. Patient dose estimation from CT scans at the Mexican National Neurology and Neurosurgery Institute

    Science.gov (United States)

    Alva-Sánchez, Héctor; Reynoso-Mejía, Alberto; Casares-Cruz, Katiuzka; Taboada-Barajas, Jesús

    2014-11-01

    In the radiology department of the Mexican National Institute of Neurology and Neurosurgery, a dedicated institute in Mexico City, on average 19.3 computed tomography (CT) examinations are performed daily on hospitalized patients for neurological disease diagnosis, control scans and follow-up imaging. The purpose of this work was to estimate the effective dose received by hospitalized patients who underwent a diagnostic CT scan using typical effective dose values for all CT types and to obtain the estimated effective dose distributions received by surgical and non-surgical patients. Effective patient doses were estimated from values per study type reported in the applications guide provided by the scanner manufacturer. This retrospective study included all hospitalized patients who underwent a diagnostic CT scan between 1 January 2011 and 31 December 2012. A total of 8777 CT scans were performed in this two-year period. Simple brain scan was the CT type performed the most (74.3%) followed by contrasted brain scan (6.1%) and head angiotomography (5.7%). The average number of CT scans per patient was 2.83; the average effective dose per patient was 7.9 mSv; the mean estimated radiation dose was significantly higher for surgical (9.1 mSv) than non-surgical patients (6.0 mSv). Three percent of the patients had 10 or more brain CT scans and exceeded the organ radiation dose threshold set by the International Commission on Radiological Protection for deterministic effects of the eye-lens. Although radiation patient doses from CT scans were in general relatively low, 187 patients received a high effective dose (>20 mSv) and 3% might develop cataract from cumulative doses to the eye lens.

  5. Patient dose estimation from CT scans at the Mexican National Neurology and Neurosurgery Institute

    Energy Technology Data Exchange (ETDEWEB)

    Alva-Sánchez, Héctor, E-mail: halva@ciencias.unam.mx [Unidad de Imagen Molecular PET/CT, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Insurgentes Sur 3877 Col. La Fama, 14269, México D.F. (Mexico); Reynoso-Mejía, Alberto [Unidad de Imagen Molecular PET/CT, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Insurgentes Sur 3877 Col. La Fama, 14269, México D.F., Mexico and Departamento de Neuroimagen, Instituto Nacional de (Mexico); Casares-Cruz, Katiuzka; Taboada-Barajas, Jesús [Departamento de Neuroimagen, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Insurgentes Sur 3877 Col. La Fama, 14269, México D.F. (Mexico)

    2014-11-07

    In the radiology department of the Mexican National Institute of Neurology and Neurosurgery, a dedicated institute in Mexico City, on average 19.3 computed tomography (CT) examinations are performed daily on hospitalized patients for neurological disease diagnosis, control scans and follow-up imaging. The purpose of this work was to estimate the effective dose received by hospitalized patients who underwent a diagnostic CT scan using typical effective dose values for all CT types and to obtain the estimated effective dose distributions received by surgical and non-surgical patients. Effective patient doses were estimated from values per study type reported in the applications guide provided by the scanner manufacturer. This retrospective study included all hospitalized patients who underwent a diagnostic CT scan between 1 January 2011 and 31 December 2012. A total of 8777 CT scans were performed in this two-year period. Simple brain scan was the CT type performed the most (74.3%) followed by contrasted brain scan (6.1%) and head angiotomography (5.7%). The average number of CT scans per patient was 2.83; the average effective dose per patient was 7.9 mSv; the mean estimated radiation dose was significantly higher for surgical (9.1 mSv) than non-surgical patients (6.0 mSv). Three percent of the patients had 10 or more brain CT scans and exceeded the organ radiation dose threshold set by the International Commission on Radiological Protection for deterministic effects of the eye-lens. Although radiation patient doses from CT scans were in general relatively low, 187 patients received a high effective dose (>20 mSv) and 3% might develop cataract from cumulative doses to the eye lens.

  6. Combined bilateral idiopathic necrosis of the humerus and femur heads: Bone scan, X-ray, CT, and MRI findings. Kombinierte beidseitige idiopathische Nekrose der Humerus- und Femurkoepfe: Skelettszintigraphie, Roentgen-, CT- und MRT-Befunde

    Energy Technology Data Exchange (ETDEWEB)

    Piepenburg, R.; Hahn, K. (Mainz Univ. (Germany). Klinik fuer Nuklearmedizin); Doll, G. (Mainz Univ. (Germany). Klinik fuer Roentgendiagnostik); Grimm, J. (Mainz Univ. (Germany). Orthopaedische Klinik)

    1992-12-01

    Untreated aseptic bone necroses close to a joint commonly leads to severe secondary arthrosis and destruction of the joint within a short time. Therefore, only a diagnosis in an early stage of the disease offers the chance of a successful joint- preserving therapy. In cases of clinically suspected aseptic bone necrosis but still negative or doubtful X-ray findings, bone scans or MRI are reliable methods of verifying the diagnosis. (orig./MG).

  7. CT scans in young people in Northern England: trends and patterns 1993-2002

    Energy Technology Data Exchange (ETDEWEB)

    Pearce, Mark S.; Salotti, Jane A.; Metcalf, Wenhua [Newcastle University, Sir James Spence Institute, Royal Victoria Infirmary, Institute of Health and Society, Newcastle upon Tyne (United Kingdom); McHugh, Kieran [Great Ormond Street Hospital for Children NHS Trust, London (United Kingdom); Kim, Kwang P. [Kyung Hee University, Department of Nuclear Engineering, Gyeongi-Do (Korea, Republic of); Craft, Alan W. [Newcastle University, Northern Institute of Cancer Research, Sir James Spence Institute, Royal Victoria Infirmary, Newcastle upon Tyne (United Kingdom); Parker, Louise [Dalhousie University and Cancer Care Nova Scotia, Departments of Medicine and Paediatrics, Population Cancer Research Program, Halifax, NS (Canada); Ron, Elaine [National Cancer Institute, Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, Bethesda, MD (United States)

    2011-07-15

    Although CT can be greatly beneficial, its relatively high radiation doses have caused public health concerns. To assess patterns in CT usage among patients aged less than 22 years in Northern England during the period 1993-2002. Electronic data were obtained from radiology information systems of all nine National Health Service trusts in the region. A total of 38,681 scans had been performed in 20,483 patients aged less than 22 years. The number of CT examinations rose, with the steepest increase between 1997 and 2000. The number of patients scanned per year increased less dramatically, with 2.24/1,000 population aged less than 22 years having one scan or more in 1993 compared to 3.54/1,000 in 2002. This reflects an increase in the median number of scans per patient, which rose from 1 in 1993 to 2 by 1999. More than 70% of CT examinations were of the head, with the number of head examinations varying with time and patient age. The frequency of CT scans in this population more than doubled during the study period. This is partly, but not wholly, explained by an increase in the number of scans per patient. (orig.)

  8. 头颈部肿瘤检查中能谱CT虚拟平扫替代常规平扫的可行性研究%Feasibility study on application of gemstone spectral CT material suppressed iodine as virtual non-contrast CT scan in head and neck neoplasms

    Institute of Scientific and Technical Information of China (English)

    杨亮; 罗德红; 赵燕风; 李琳; 林蒙; 冯世超; 周纯武

    2015-01-01

    Objective To evaluate the feasibility of applying spectral CT material suppressed iodine (MSI) imaging as virtual plain CT scan to replace traditional non-contrast (TNC) CT in head and neck neoplasms. Methods A total of 52 patients with initial diagnosis of head and neck neoplasms underwent TNC CT scanning and spectrum mode enhanced scanning in the head and neck with spectral CT. With GSI Volume Viewer software from GE AW4.6 workstation, the enhanced scanning data were processed and MSI images were acquired. The CT values of different tissues (fat, erector spinae, cervical vertebrae, thyroid, and brain parenchyma) and the enhancement rate in erector spinae, carotid sinus were compared between MSI and TNC images. Image quality was objectively evaluated in noise and SNR for MSI and TNC images, while the subjective evaluation included the visibility of lesions, subjective acceptance rate, diagnostic efficacy (with/without lesions or lesion calcification, necrosis). Radiation dose including volume CT dose index (CTDIvol) and effective dose (ED) was compared between MSI and TNC. Results (1) CT values of erector spinae on MSI and TNC imaging were(52 ± 6)and(52 ± 7)HU respectively, and the difference between the two image modes was not significant(t=0.39,P>0.05). CT values on MSI and TNC Imaging were[-74 (-86,-59)HU]and[-79(-73,-61)HU]for fat (Z=-2.71, P0.05). The difference of carotid sinus enhancement rate was significant 5.75(4.70,6.73) and 4.37(3.91,5.61) respectively, Z=-5.50, P0.05).Unacceptable and acceptable cases in imaging quality of MSI were 3 and 49 respectively, while those were 2 and 50 in TNC group. Subjective acceptance rate between MST and TNC images was not significantly different(2=0.01,P>0.05). (5) Diagnostic performance evaluation showed that the consistency of two observers was good in detecting lesions, necrosis and calcification between MSI and TNC image, with K value 0.93, 0.83 and 0.90 respectively (P0.05);脂肪分别为-74(-86,

  9. Preoperative CT scanning of 70 cases of rheumatic valvular disease

    Energy Technology Data Exchange (ETDEWEB)

    Take, Akira; Matuzaki, Shigeru; Oki, Shinichi (Jichi Medical School, Minamikawachi, Tochigi (Japan)) (and others)

    1992-05-01

    Seventy patients with rheumatic valvular disease were evaluated with preoperative CT scanning. The correlation of the obtained CT images to the operative findings were examined. Left atrial thrombi were found in 24 cases at the operation. CT scan had detected thrombi in 19 cases (79.2%) and echocardiography in 15 (62.5%). CT failed to find them in 5 cases in which the left atrial thrombi were less than 3 g. Echocardiogram, however, failed to detect thrombi in 9 cases, the largest being 14 g. There were 15 cases with left atrial calcification, in which 10 cases had left atrial thrombi. Nine cases out of these 10 cases had rough left atrial surface after thrombectomy. Early postoperative CT of 10 with left atrial calcification showed recurrent left atrial thrombi in 4 (40%) cases. Mitral valve calcification was found in 42 cases during operation. CT scan was able to detect it in 40 (95.2%), while echocardiogram detected in 34 cases (81.0%) (p<0.05). All mitral valves with calcification required replacement. Out of 30 cases with non calcified mitral valves, 9 underwent OMC, and the other 21 underwent mitral valve replacement. Aortic valve calcification was found in 9 out of 11 cases of aortic stenosis. All has been diagnosed by CT scan. In conclusion, 1. in detecting the left atrial thrombi, CT scan was superior to echo-cardiography, and provided useful information for planning the operative procedure including atrial approach and valvular manipulation, 2. CT scan could detect calcification of left atrial wall which had high incidence of thrombus formation and rough left atrial surface, 3. CT scan could detect calcification of both mitral and aortic valve, and showed the severity of valvular structural changes. (author).

  10. CT SCAN: THE TOUR GUIDE FOR THE MANAGEMENT OF THE EDH

    Directory of Open Access Journals (Sweden)

    Somashekhar

    2015-02-01

    Full Text Available EDH is considered as common and one of the important preventable complications in head injury. This condition may require aggressive management depending on the various clinical and radiological factors on continuous assessment of the patients. This study was carried out to evaluate the presentation of patients with extradural haematoma secondary to head injury an d to assess the factors influencing the mode of management and also the outcome. 50 patients with cranial extradural haematoma were admitted in the neurosurgical department during the period of 2 years. All the patients with head injury on CT scan diagnose d to have EDH were included in the study. The management includes conservative measures and/or decompressive craniotomy. Temporo - parietal (20% and temporal region(20% was the most common location of EDH. The most significant factors which influences surg ical mode of management were higher age group, lower GCS and the CT scan variables showing greater clot volume and thickness. Increased interval between the times of trauma to surgery and lower GCS was very significantly associated with unfavourable outcom e along with CT scan variables irrespective of mode of management. From this study we concluded that neurological status of the patients on presentation and the volumetric details of EDH are the most important factors in management and outcome of EDH. With early detection and treatment due to better connectivity of the patients to hospitals, with the help of CT scan and good hospital care, we can expect a decrease in the number of unfavorable outcomes.

  11. Diagnostic accuracy of CT scan in abdominal blunt trauma

    Institute of Scientific and Technical Information of China (English)

    Javad Salimi; Khadyjeh Bakhtavar; Mehdi Solimani; Patrcia Khashayar; Ali Pasha Meysamie; Moosa Zargar

    2009-01-01

    Obiective: To evaluate the sensitivity and specificity of CT scan findings in Patients ith blunt abdominal trauma admitted to the university hospital.Methods: All the atients ith blunt abdominal trauma admitted at a tertiary teaching trauma center in Iran between 2005 and 2007 were enrolled in this study.In the absence of any clinical anifestations,he patients underwent a diagnostic CT scan.Laparatomy was performed in those with positive CT results.Others were observed for 48 hours and discharged in case no problem as reported;otherwise they underwent laparatomy.Information on patients'demographic ata,mechanism of trauma,indication for CT scan,CT scan findings,results of laparotomy ere gathered.The sensitivity,specificity and accuracy of the CT-scan images in regard ith the organ injured were calculated.The sensitivity,specificity and accuracy of the T scan were calculated in each case.Results: CT Scan had the highest sensitivity for etecting the injuries to liver (100%) and spleen (86.6%).The specificity of the method or detecting retroperitoneal hematoma (100%) and injuries to kidney (93.5%) was higher han other organs.The accuracy of CT images to detect the injuries to spleen,liver,idney and retroperitoneal hematoma was reported to be 96.1%,94.4%,91.6% and 91.6% espectively.Conclusion: The findings of the present study reveal that CT scan could econsidered as a good choice,especially for patients with blunt abdominal trauma in eaching hospitals where the radiologic academic staff is not present in the hospital in the night shifts.

  12. A method to quantify and visualize femoral head intraosseous arteries by micro-CT.

    Science.gov (United States)

    Qiu, Xing; Shi, Xiaotian; Ouyang, Jun; Xu, Dachuan; Zhao, Dewei

    2016-08-01

    We describe a technique for perfusing a barium sulphate suspension into the intraosseous artery. Following the perfusion of abarium sulphate suspension into 14 fresh lower limbs of Chinese cadavers, micro-CT scanning was applied to digitize, quantify and visualize the intraosseous arteries in the human femoral heads. Then, the femoral heads were removed and subjected to micro-CT scanning. The data were imported into the amira and mimics programs to reconstruct and quantify the intraosseous arteries. The femoral head intraosseous artery lengths, areas, volumes, and femoral head bone volumes were quantified. The artery densities and artery ratios were calculated and analysed with independent-samples t-tests. The intraosseous vasculature volume renderings were displayed as screenshots and videos made with amira. Many intraosseous artery study technologies were compared. The barium sulphate suspension was milky white in colour. The perfusion of the barium sulphate suspension followed by micro-CT scanning provided a good representation of the intraosseous artery. The femoral head intraosseous artery lengths, areas and volumes, and the femoral head bone volumes were displayed as the X¯±S . No differences were observed between the left and right femoral head intraosseous arteries in terms of the artery densities or artery ratios. The volume renderings and 3-D orthogonal projections displayed the overall distributions of the intraosseous arteries. The videos clearly demonstrated the entry sites of the nutrition-carrying arteries, their courses and branches, and the intraosseous arterial anastomoses. Our technique is the simplest and least time-consuming method of producing accurate vascular three-dimensional reconstructions. The perfusion of a barium sulphate suspension into intraosseous arteries combined with micro-CT scanning can deliver high-resolution 3-D digitized data and images of intraosseous arteries. This technique does not require bone decalcification or bone

  13. Relationship between Hounsfield unit in CT scan and gray scale in CBCT

    Science.gov (United States)

    Kamaruddin, Noorshaida; Rajion, Zainul Ahmad; Yusof, Asilah; Aziz, Mohd Ezane

    2016-12-01

    Cone-beam computed tomography (CBCT) is an imaging system which has advantages over computed tomography (CT). Recently, CBCT has become widely used for oral and maxillofacial imaging. In CT scan, Hounsfield Unit (HU) is proportional to the degree of x-ray attenuation by the tissue. In CBCT, the degree of x-ray attenuation is shown by gray scale (voxel value). The aim of the present (in vitro) study was to investigate the relationship between gray scale in CBCT and HU in CT scan. In this descriptive study, the anthropomorphic head phantom was scanned with CBCT and CT scanner. Gray scales and HUs were detected on images at the crown of the teeth, trabecular and cortical bone of mandible. The images were analyzed to obtain the gray scale value and HU value. The obtained value then used to investigate the relationship between CBCT gray scales and HUs. For the statistical analysis, t-test, Pearson's correlation and regression analysis were used. The differences between the gray scale of CBCT and HU of CT were statistically not significant, whereas the Pearson's correlation coefficients demonstrated a statistically significant correlation between gray scale of CBCT and HU of CT values. Considering the fact that gray scale in CBCT is important in pre assessment evaluation of bone density before implant treatments, it is recommended because of the lower dose and cost compared to CT scan.

  14. Multimodal imaging of the human temporal bone: A comparison of CT and optical scanning techniques

    Science.gov (United States)

    Voie, Arne H.; Whiting, Bruce; Skinner, Margaret; Neely, J. Gail; Lee, Kenneth; Holden, Tim; Brunsden, Barry

    2003-10-01

    A collaborative effort between Washington University in St. Louis and Spencer Technologies in Seattle, WA has been undertaken to create a multimodal 3D reconstruction of the human cochlea and vestibular system. The goal of this project is to improve the accuracy of in vivo CT reconstructions of implanted cochleae, and to expand the knowledge of high-resolution anatomical detail provided by orthogonal-plane optical sectioning (OPFOS). At WUSL, computed tomography (CT) images of the cochlea are used to determine the position of cochlear implant electrodes relative to target auditory neurons. The cochlear implant position is determined using pre- and post-operative CT scans. The CT volumes are cross-registered to align the semicircular canals and internal auditory canal, which have a unique configuration in 3-D space. The head of a human body donor was scanned with a clinical CT device, after which the temporal bones were removed, fixed in formalin and trimmed prior to scanning with a laboratory Micro CT scanner. Following CT, the temporal bones were sent to the OPFOS Imaging Lab at Spencer Technologies for a further analysis. 3-D reconstructions of CT and OPFOS imaging modalities were compared, and results are presented. [Work supported by NIDCD Grants R44-03623-5 and R01-00581-13.

  15. CT scan findings in cerebral paragonimiasis

    Energy Technology Data Exchange (ETDEWEB)

    Udaka, Fukashi; Okuda, Bungo; Okada, Masako; Okae, Shunji; Kameyama, Masakuni (Chikamori Hospital, Kochi (Japan))

    1982-12-01

    Computed tomography was performed on 5 patients with chronic cerebral paragonimiasis. CT showed solitary or multiple, amorphous, round, or oval calcifications, and ventricular enlargement in all 5 cases. A large low-density area is also found in 4 of the 5 cases. These CT findings are compatible with previously reported findings of simple X-ray films of the skull, pneumoencephalography, and pathological studies.

  16. Relationship between Hounsfield Unit in CT Scan and Gray Scale in CBCT

    Directory of Open Access Journals (Sweden)

    Tahmineh Razi

    2014-06-01

    Full Text Available Background and aims. Cone-beam computed tomography (CBCT is an imaging system which has many advantages over computed tomography (CT. In CT scan, Hounsfield Unit (HU is proportional to the degree of x-ray attenuation by the tissue. In CBCT, the degree of x-ray attenuation is shown by gray scale (voxel value. The aim of the present study was to investigate the relationship between gray scale in CBCT and Hounsfield Unit (HU in CT scan. Materials and methods. In this descriptive study, the head of a sheep was scanned with 3 CBCT and one medical CT scanner. Gray scales and HUs were detected on images. Reconstructed data were analyzed to investigate relationship between CBCT gray scales and HUs. Results. A strong correlation between gray scales of CBCT and HUs of CT scan was determined. Conclusion. Considering the fact that gray scale in CBCT is the criteria in measurement of bone density before implant treatments, it is recommended because of the lower dose and cost compared to CT scan.

  17. Relationship between Hounsfield Unit in CT Scan and Gray Scale in CBCT.

    Science.gov (United States)

    Razi, Tahmineh; Niknami, Mahdi; Alavi Ghazani, Fakhri

    2014-01-01

    Background and aims. Cone-beam computed tomography (CBCT) is an imaging system which has many advantages over computed tomography (CT). In CT scan, Hounsfield Unit (HU) is proportional to the degree of x-ray attenuation by the tissue. In CBCT, the degree of x-ray attenuation is shown by gray scale (voxel value). The aim of the present study was to investigate the relationship between gray scale in CBCT) and Hounsfield Unit (HU) in CT scan. Materials and methods. In this descriptive study, the head of a sheep was scanned with 3 CBCT and one medical CT scanner. Gray scales and HUs were detected on images. Reconstructed data were analyzed to investigate relationship between CBCT gray scales and HUs. Results. A strong correlation between gray scales of CBCT and HUs of CT scan was determined. Conclusion. Considering the fact that gray scale in CBCT is the criteria in measurement of bone density before implant treatments, it is recommended because of the lower dose and cost compared to CT scan.

  18. CT scan of the hypopharynx and larynx. Value of phonation scans

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Naoko; Anno, Hirofumi; Takahashi, Masaki; Koga, Sukehiko; Mori, Shigeki; Iwata, Shigenobu; Ikuta, Katsumi; Mashita, Shinichi.

    1988-08-01

    29 patients with hypopharyngeal or laryngeal disorders were sustained phonation of vowel /E/ at their comfortable pitch and intensity levels on their CT scans. These images were compared with CT scans during quiet breathing or breath holding. The pyriform sinuses and the aryepiglottic folds were better visualized and the details of the glottis and the laryngeal ventricles were demonstrable during phonation.

  19. Solitary pulmonary granuloma with marked enhancement on dynamic CT scanning

    Energy Technology Data Exchange (ETDEWEB)

    Stark, P.; Wong, V.; Gold, P.

    1988-10-01

    A patient is described who presented with a vividly enhancing solitary pulmonary nodule during dynamic CT scanning. This mass proved to represent a granuloma due to coccidioidomycosis. The presumptive mechanism of enhancement as well as the differential diagnosis are discussed.

  20. CT Scans Might Help Gauge Heart Attack Risk

    Science.gov (United States)

    ... html CT Scans Might Help Gauge Heart Attack Risk Researchers aim to identify vulnerable patients before damage becomes irreversible To use ... significantly narrowed, Antoniades said. No currently available test identifies ... journal Science Translational Medicine . About 750,000 Americans have ...

  1. [Direct total body CT scan in multi-trauma patients

    NARCIS (Netherlands)

    Sierink, J.C.; Saltzherr, T.P.; Edwards, M.J.R.; Beuker, B.J.; Patka, P.; Goslings, J.C.; studiegroep, R.

    2012-01-01

    BACKGROUND: Immediate total body computed tomography (CT) scanning has become important in the early diagnostic phase of trauma care because of its high diagnostic accuracy. However, literature provides limited evidence whether immediate total body CT leads to better clinical outcome then convention

  2. 小儿颅内血肿的CT诊断及其对治疗的意义%The Value of CT Scanning in the Management of Children's Head Injury

    Institute of Scientific and Technical Information of China (English)

    夏佐中; 薛启苏; 魏光辉; 罗思维

    1988-01-01

    本院由CT诊断的小儿颅内血肿33例,行手术治疗22例,非手术治疗11例.颅伤后的意识状况、血肿的大小、位置和是否伴有开放性颅脑损伤等是小儿颅内血肿治疗方式的选择依据.CT可测定血肿的大小,结合患儿意识状况对选择治疗方式起重要作用.%Reviewing 33 cases of intracranial hematoma found by CT scanning,the authors made the following indications of craniotomy.Progressive mental deterioration is the vital important indication for operation.Besides.A hematoma combined with an open cranial wound,a depression cranial fracture deeper than 0.5cm,and/or a hematoma in the posterior cranial fossa are also indications for operation.11 cases of intracranial hematoma recovered without operation.These patients showed no mental deterioration and their CT showed a hematoma smal ler than 40ml.10 of them had CT follow-up,which showed a total resolution in 1-9 months.

  3. Abdominal CT scanning in critically ill surgical patients.

    Science.gov (United States)

    Norwood, S H; Civetta, J M

    1985-01-01

    Clinical parameters, intensive care unit (ICU) course, abdominal computed tomography (CT) scans, and the clinical decisions of 53 critically ill patients were reviewed to determine the influence of the CT scan. No scans were positive before the eighth day. Sensitivity was 48% and specificity, 64%. Seventeen (23%) scans of the 72 provided beneficial results: eight localized abscesses that were drained; nine were negative and not operated on. Five (7%) scans provided detrimental information: scan negative with abscess discovered or scan positive but negative laparotomy. Fifty (70%) scans were either of no help or not used in management. The mortality rate was 50% when CT led to an intervention, and 47% in the entire group. Hospital charges were +33,408. Personnel time and cost were 497 hours and +3658; of the total +37,066, 77% (+28,541) could be considered wasted. From these data, it was concluded that CT scans should be used to confirm abscesses, not to search for a source of sepsis. PMID:4015222

  4. A Neonatal Bimodal MR-CT Head Template

    Science.gov (United States)

    Mohtasebi, Mehrana; Abrishami Moghaddam, Hamid; Grebe, Reinhard; Gity, Masoumeh; Wallois, Fabrice

    2017-01-01

    Neonatal MR templates are appropriate for brain structural analysis and spatial normalization. However, they do not provide the essential accurate details of cranial bones and fontanels-sutures. Distinctly, CT images provide the best contrast for bone definition and fontanels-sutures. In this paper, we present, for the first time, an approach to create a fully registered bimodal MR-CT head template for neonates with a gestational age of 39 to 42 weeks. Such a template is essential for structural and functional brain studies, which require precise geometry of the head including cranial bones and fontanels-sutures. Due to the special characteristics of the problem (which requires inter-subject inter-modality registration), a two-step intensity-based registration method is proposed to globally and locally align CT images with an available MR template. By applying groupwise registration, the new neonatal CT template is then created in full alignment with the MR template to build a bimodal MR-CT template. The mutual information value between the CT and the MR template is 1.17 which shows their perfect correspondence in the bimodal template. Moreover, the average mutual information value between normalized images and the CT template proposed in this study is 1.24±0.07. Comparing this value with the one reported in a previously published approach (0.63±0.07) demonstrates the better generalization properties of the new created template and the superiority of the proposed method for the creation of CT template in the standard space provided by MR neonatal head template. The neonatal bimodal MR-CT head template is freely downloadable from https://www.u-picardie.fr/labo/GRAMFC. PMID:28129340

  5. Hybrid detection of lung nodules on CT scan images

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Lin; Tan, Yongqiang; Schwartz, Lawrence H.; Zhao, Binsheng, E-mail: bz2166@columbia.edu [Department of Radiology, Columbia University Medical Center, 630 West 168th Street, New York, New York 10032 (United States)

    2015-09-15

    Purpose: The diversity of lung nodules poses difficulty for the current computer-aided diagnostic (CAD) schemes for lung nodule detection on computed tomography (CT) scan images, especially in large-scale CT screening studies. We proposed a novel CAD scheme based on a hybrid method to address the challenges of detection in diverse lung nodules. Methods: The hybrid method proposed in this paper integrates several existing and widely used algorithms in the field of nodule detection, including morphological operation, dot-enhancement based on Hessian matrix, fuzzy connectedness segmentation, local density maximum algorithm, geodesic distance map, and regression tree classification. All of the adopted algorithms were organized into tree structures with multi-nodes. Each node in the tree structure aimed to deal with one type of lung nodule. Results: The method has been evaluated on 294 CT scans from the Lung Image Database Consortium (LIDC) dataset. The CT scans were randomly divided into two independent subsets: a training set (196 scans) and a test set (98 scans). In total, the 294 CT scans contained 631 lung nodules, which were annotated by at least two radiologists participating in the LIDC project. The sensitivity and false positive per scan for the training set were 87% and 2.61%. The sensitivity and false positive per scan for the testing set were 85.2% and 3.13%. Conclusions: The proposed hybrid method yielded high performance on the evaluation dataset and exhibits advantages over existing CAD schemes. We believe that the present method would be useful for a wide variety of CT imaging protocols used in both routine diagnosis and screening studies.

  6. An evaluation of cranial CT scanning in clinical psychiatry.

    Science.gov (United States)

    Colohan, H; O'Callaghan, E; Larkin, C; Waddington, J L

    1989-07-01

    From 6,300 psychiatric admissions over a 37 month period, all 54 patient referrals for CT were identified and their charts reviewed. CT influenced diagnosis, management or prognosis in 11.7 percent of patients scanned. There was poor correlation between organicity on CT scan and findings on physical examination, laboratory testing, EEG and psychological testing. The mental state examination was the single significant correlate of CT abnormality. We suggest that the use of a formalised mental state examination such as the Mini Mental State, in addition to the usual clinical assessment of mental state, may improve the accuracy of prediction of abnormality on CT scan. The introduction of X-ray computed tomography (CT) is recognised to be one of the most important innovations in the recent history of clinical medicine. In neurology the value of a non-invasive technique for examining the intracranial contents was quickly realised in the areas of diagnosis, particularly in the detection of vascular accidents and tumours. CT has also attained a significant place in psychiatry. In research studies, it has provided important information on schizophrenia, alcoholism and chronic organic reactions. The place of CT in clinical psychiatry is less clear. As its availability has increased, such scans are being requested with increasing frequency in psychiatric patients. Cranial CT is a highly sensitive diagnostic procedure which, when used unselectively, may result in the discovery of incidental findings. Until recently, a function of the psychiatrist in relation to diagnosis was to first seek to distinguish symptoms produced by organic pathology from those produced by functional illness.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Thin-section CT scan of the pituitary gland

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, T.; Inoue, Y.; Taniguchi, S. (Osaka City Univ. (Japan). Faculty of Medicine)

    1982-02-01

    Topographic anatomy of the pituitary fossa was studied by 2 mm thin-section CT scan (Somatom II). Nineteen with normal pituitary (control group) and 20 with suspected pituitary abnormality were selected. Plain and contrast CT were performed in all cases. Contrast CT was carried out immediately after the rapid infusion of 220 ml of 30% iodinated contrast medium. In all of control group but two, pituitary gland was detected as homogeneous density and its density was the same as the density of normal brain tissues, and was enhanced in degree of about 25 CT number. In 2 cases, small low density was visualized in the pituitary gland. Pituitary gland was differentiated from cavernous sinus was usually higher than the pituitary gland. In the abnormal group, microadenoma of the pituitary gland was diagnosed in 5 cases and 3 out of 5 cases was proved by surgery. All 3 microadenomas proved slightly dense by plain CT and enhanced higher than normal pituitary gland by contrast CT. Polytomograms showed no abnormality of the sella turcica in one of these 3 cases. Although 3 microadenomas were detected by the abnormal enhancement, we are not sure whether all microadenoma can be detected by CT alone. Arachnoid herniation into the pituitary fossa was diagnosed in 7 of the control group and 2 of the abnormal group. Four out of these 9 cases were verified by using Metrizamide CT. By plain thin-section CT, the diagnosis of arachnoid herniation seems to be possible without Metrizamide CT.

  8. Neurological ct Scan Value for Ictus in Cienfuegos Province

    Directory of Open Access Journals (Sweden)

    Idaylí Pérez Rodríguez

    2007-05-01

    Full Text Available Backgrounds: CT scan constitutes a very important technique in the diagnosis of the cerebrovascular disease. The impact this transcendental event had and will continue having in the medicine area is impossible to state in terms of dimensions during the next years. Objective: To determine the neurological CT scan value for ictus in our milieu. Methods: A retrospective, prospective, longitudinal study of a series of cases performed during a review of statistical reports as well as that of Stroke data base which stores information of patients with neurocitus in our province, and which is based on others aspects founds by means of neurological CT scan. Results: CT scan allowed us to diagnose the type of cerebrovascular event (75.55 % ischemic events, 24.45% hemorrhagic events. It also contributed to the necessary data such as the localization (with predominium of 35.55% in more than one area, and 7.40 % in the parietal area. The presence of cerebral edema was verified in 16.29% of the cases as well as displacement of the midline in 7.40 % both associated to a torpid evolution. It incorporated the Fisher and Le Roux scales showing their prognosis value with elevated measures for deceased patients and decreased values for survivors without disability. Conclusions: The diagnosis and prognosis value were proved as well as CT scan behavior in our milieu. These aspects permit the reliable introduction of new therapeutic modalities in our province.

  9. CT scan of the brain (image)

    Science.gov (United States)

    ... CAT scan (computed tomography) is a much more sensitive imaging technique than x-ray, allowing high definition not only of the bony structures, but of the soft tissues. Clear images of organs such as the brain, muscles, joint structures, veins ...

  10. Classication Methods for CT-Scanned Carcass Midsections

    DEFF Research Database (Denmark)

    Skytte, Jacob Lercke; Dahl, Anders Lindbjerg; Larsen, Rasmus

    2011-01-01

    Computed tomography (CT) has successfully been applied in medical environments for decades. In recent years CT has also made its entry to the industrial environments, including the slaughterhouses. In this paper we investigate classication methods for an online CT system, in order to assist...... in the segmentation of the outer fat layer in the mid- section of CT-scanned pig carcasses. Prior information about the carcass composition can potentially be applied for a fully automated solution, in order to optimize the slaughter line. The methods comprise Markov Random Field and contextual Bayesian classication......, and are adapted to use neighbourhood information in 2D and 3D. Articial Poisson noise is added to the provided dataset to determine how well each of the methods handles noise. Good noise handling will allow lower dose scannings. The investigated methods did not perform better than the reference model in terms...

  11. MRI of patients with cerebral palsy and normal CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Bogaert, P. van; Szliwowski, H.B. (Hopital Erasme, Brussels (Belgium). Dept. of Neurology); Baleriaux, D.; Christophe, C. (Hopital Erasme, Brussels (Belgium). Dept. of Radiology (Neuroradiology))

    1992-02-01

    Three children with clinical evidence of cerebral palsy (CP) and normal cerebral computed tomography (CT) scans were evaluated by magnetic resonance imaging (MRI) to identify CT-undetectable white matter lesions in the watershed zones of arterial territories. The two patients with spastic diplegia showed bilateral lesions either in the subcortical regions or in the occipital periventricular regions. The patient with congenital hemiplegia exhibited unilateral lesions in the periventricular region. We conclude that MRI is more informative than CT for the evaluation of patients with CP. (orig.).

  12. Comparison of intracranial computed tomographic (CT) findings in pediatric abusive and accidental head trauma

    Energy Technology Data Exchange (ETDEWEB)

    Hymel, K.P. [University of Colorado Health Sciences Center, 1056 East 19th Avenue, Denver, CO 80218 (United States); Rumack, C.M. [University of Colorado Health Sciences Center, 1056 East 19th Avenue, Denver, CO 80218 (United States); Hay, T.C. [University of Colorado Health Sciences Center, 1056 East 19th Avenue, Denver, CO 80218 (United States); Strain, J.D. [University of Colorado Health Sciences Center, 1056 East 19th Avenue, Denver, CO 80218 (United States); Jenny, C. [University of Colorado Health Sciences Center, 1056 East 19th Avenue, Denver, CO 80218 (United States)

    1997-09-01

    Background. Child abuse specialists rely heavily on diagnostic neuroimaging. Objectives. Study objectives were: (1) to compare the frequencies of six specific intracranial CT abnormalities in accidental and non-accidental pediatric head trauma, and (2) to assess interobserver agreement regarding these CT findings. Materials and methods. Three pediatric radiologists blindly and independently reviewed cranial CT scans of pediatric patients who sustained closed head trauma between 1991 and 1994. All patients were less than 4 years of age. Study cases included thirty-nine (50 %) with non-accidental head trauma and thirty-nine (50 %) with accidental head trauma. Each scan was evaluated for the presence or absence of the following six intracranial findings: (1) interhemispheric falx hemorrhage, (2) subdural hemorrhage, (3) large (non-acute) extra-axial fluid, (4) basal ganglia edema, (5) posterior fossa hemorrhage, and (6) frontal-parietal shearing tear(s). Interobserver agreement was calculated as the percentage of total cases in which all reviewers agreed a specific CT finding was present or absent. Diagnosis required independent agreement by all three pediatric radiologists. The frequencies of these six intracranial CT abnormalities were compared between the two study groups by Chi-square analysis and Fisher`s exact test. Results. Interobserver agreement between radiologists was greater than 80 % for all lesions evaluated, with the exception of frontal-parietal shearing tear(s). Interhemispheric falx hemorrhage, subdural hemorrhage, large (non-acute) extra-axial fluid, and basal ganglia edema were discovered significantly more frequently in non-accidental trauma (P {<=}.05). Conclusion. Although not specific for child abuse, discovery of these intracranial CT abnormalities in young patients should prompt careful evaluation of family and injury circumstances for indicators of non-accidental trauma. (orig.). With 6 figs., 2 tabs.

  13. CT-scanning of ancient Greenlandic Inuit temporal bones

    DEFF Research Database (Denmark)

    Homøe, P; Lynnerup, N; Videbaek, H

    1992-01-01

    bones. The CT-scans showed sclerosing and obliteration of the air cells and even destruction of the cellular septae, and a high degree of irregularity of the cells. Sclerosing of the surrounding bone tissue was also found. The findings in one cranium were dubious and could both be regarded...... as a congenital malformation or an infection in infanthood. CT-scan confirms and even adds to the results of conventional X-ray of temporal bones making hypotheses of paleopathology more reliable. The findings also support the environmental theory of pneumatization of the air cell system in the temporal bones....

  14. Analysis of cranial CT-scan findings in cerebral palsy

    Energy Technology Data Exchange (ETDEWEB)

    Wada, F.; Andoh, T.; Une, K.; Takamatsu, T. (Kitakyushu Municipal Sogo-Ryoiku Center (Japan))

    1981-06-01

    CT-scan findings of 87 cerebral palsied children were studied. They consist of 23 cases of spastic quadriplegia, 9 cases of diplegia, 12 cases of paraplegia, 24 cases of athetosis and mixed type, and 19 cases of hemiplegia. In the former four types, ventricular dilatation and cortical atrophy were measured and abnormal changes in cerebral substance and cerebellar atrophy were observed. Spastic quadriplegia showed most intense changes in every aspect of the abnormalities, while paraplegia had almost normal appearance. Athetosis and mixed type had moderate changes. Hemiplegia always showed asymmetrical view on CT-scan, dilatation of lateral ventricle or atrophy of hemisphere in contralateral side being observed.

  15. 多层螺旋CT增强扫描在胰头肿块性胰腺炎及胰头癌鉴别诊断中的价值%Multislice CT Enhanced Scan in the Pancreatic Head Tumor Pancreatitis and Pancreatic Head Carcinoma in the Differential Diagnosis Value

    Institute of Scientific and Technical Information of China (English)

    王志刚; 周宇; 葛攀; 赵德官; 李建江

    2015-01-01

    目的分析多层螺旋CT动态增强扫描在胰头肿块性胰腺炎及胰头癌的CT表现,探讨鉴别要点,提高诊断准确率。方法回顾分析我院23例经手术病理证实或临床随访证实胰头部肿块型胰腺炎与胰头癌患者,采用多层螺旋CT增强扫描、薄层重建及图像后处理,多种重组模式观察,分析其影像学特点,比较统计学差异。结果①肿块型胰腺炎与胰腺癌增强后动脉期、胰腺实质期CT值分别采用配对检验,差异有统计学意义(动脉期=6.45;胰腺实质期=5.72,均0.05);悠假囊肿发生率差异无统计学意义(=2.61,>0.05);忧胰胆管扩张情况差异有统计学意义(=5.37,2.78);②Incidence of pseudocyst there was no statistical y significant dif erenceχ²=2.61, >2.61);③The expansion of pancreatic and dif erence was statistical y significant (χ²=5.37, <0.05);④Fascia around the kidney thickening of the dif erence was statistical y significant (χ²=9.27, <0.05). Conclusion Enhanced CT scan in the pancreatic head tumor sex pancreatitis and pancreatic head carcinoma have certain dif erences in performance, as an important clinical basis for the dif erential diagnosis.

  16. Optimization of megavoltage CT scan registration settings for brain cancer treatments on tomotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Woodford, Curtis; Yartsev, Slav; Van Dyk, Jake [London Regional Cancer Program, London Health Sciences Centre, 790 Commissioners Road East, London, Ontario (Canada)

    2007-04-21

    This study aims to determine the settings that provide the optimal clinical accuracy and consistency for the registration of megavoltage CT (MVCT) with planning kilovoltage CT image sets on the Hi-ART tomotherapy system. The systematic offset between the MVCT and the planning kVCT was determined by registration of multiple MVCT scans of a head phantom aligned with the planning isocentre. Residual error vector lengths and components were used to quantify the alignment quality for the phantom shifted by 5 mm in different directions obtained by all 27 possible combinations of MVCT inter-slice spacing, registration techniques and resolution. MVCT scans with normal slices are superior to coarse slices for registration of shifts in the superior-inferior, lateral and anterior-posterior directions. Decreasing the scan length has no detrimental effect on registration accuracy as long as the scan lengths are larger than 24 mm. In the case of bone technique and fine resolution, normal and fine MVCT scan slice spacing options give similar accuracy, so normal mode is preferable due to shorter procedure and less delivered dose required for patient set-up. A superior-inferior field length of 24-30 mm, normal slice spacing, bone technique, and fine resolution is the optimum set of registration settings for MVCT scans of a Rando head phantom acquired with the Hi-ART tomotherapy system, provided the registration shifts are less than 5 mm. (note)

  17. Clinical predictors of abnormal computed tomography scan in minor head trauma in children under 2 years old

    Directory of Open Access Journals (Sweden)

    Sepideh Lotfi Sadigh

    2015-03-01

    Full Text Available Introduction: Minor blunt head trauma is a common reason for children to present to the emergency department (ED. Crania computed tomography (CT is the choice for evaluating children with blunt head trauma in the ED, but few shows abnormal findings. In this study, we aim to evaluate CT findings in children with blunt head trauma and clinical symptoms to identify clinical predictors of abnormal CT scans. Methods: In this prospective study, 218 children under 2 years of age (121 male and 97 female with mean age of 11.24 ± 4.31 months with compliant of minor blunt head trauma visiting the ED between April 2011 and April 2014 were included. Physical examination and clinical symptoms, as well as CT findings and patients’ outcome were evaluated. Results: Physical examinations were normal in 95.9%, and clinical symptoms were present only in 25.7% including vomiting in 16.1%, loss of consciousness (LOC in 8.3%, ear/nose bleeding in 4.1% and seizure in 5.5%. CT scan was requested in 189 cases (86.7% of which, 7.9% were abnormal including linear fracture in 5.3%, subgaleal hematoma in 1.1% and depressed fracture, subcutaneous hematoma and intracranial hemorrhage (ICH each in 0.5%. Among all cases, 89.0% were discharged from ED with no further observation, 6.0% discharged after 48 h observation and 5.0% were hospitalized. There was a significant correlation between abnormal CT findings and having any clinical symptoms, vomiting and Ear/nose bleeding. Conclusion: In children under 2 years old with minor blunt head trauma, most CT scans are unnecessary. Considering clinical symptoms as predictors of abnormal CT scans we can reduce unnecessary ones.

  18. Automated lung segmentation of low resolution CT scans of rats

    Science.gov (United States)

    Rizzo, Benjamin M.; Haworth, Steven T.; Clough, Anne V.

    2014-03-01

    Dual modality micro-CT and SPECT imaging can play an important role in preclinical studies designed to investigate mechanisms, progression, and therapies for acute lung injury in rats. SPECT imaging involves examining the uptake of radiopharmaceuticals within the lung, with the hypothesis that uptake is sensitive to the health or disease status of the lung tissue. Methods of quantifying lung uptake and comparison of right and left lung uptake generally begin with identifying and segmenting the lung region within the 3D reconstructed SPECT volume. However, identification of the lung boundaries and the fissure between the left and right lung is not always possible from the SPECT images directly since the radiopharmaceutical may be taken up by other surrounding tissues. Thus, our SPECT protocol begins with a fast CT scan, the lung boundaries are identified from the CT volume, and the CT region is coregistered with the SPECT volume to obtain the SPECT lung region. Segmenting rat lungs within the CT volume is particularly challenging due to the relatively low resolution of the images and the rat's unique anatomy. Thus, we have developed an automated segmentation algorithm for low resolution micro-CT scans that utilizes depth maps to detect fissures on the surface of the lung volume. The fissure's surface location is in turn used to interpolate the fissure throughout the lung volume. Results indicate that the segmentation method results in left and right lung regions consistent with rat lung anatomy.

  19. Incidental cranial CT findings in head injury patients in a Nigerian tertiary hospital

    Directory of Open Access Journals (Sweden)

    Godwin I Ogbole

    2015-01-01

    Full Text Available Background: Incidental findings on computed tomography (CT scans are occasionally noted in patients presenting with head injury. Since it can be assumed that head injured patients are of normal health status before the accident, these findings may be a representation of their frequency in the general population. Our aim was to determine the prevalence of such incidental findings among head injured patients in Nigeria′s foremost center of clinical neurosciences. Materials and Methods: We conducted a retrospective review of CT scan images of 591 consecutive eligible patients over a 5-year period (2006-2010 to identify incidental findings. The images were evaluated by consensus agreement of two radiologists. Associations with gender and age were explored using appropriate statistical tests with an alpha level of 0.05. Results: The mean patient age was 34.6 ± 21.2 years, and male to female ratio was 3.2: 1. Incidental findings were noted in 503/591 (85.1 % of the scans. Intracranial calcification was the commonest finding occurring in 61.8% of patients. Over 90% of the findings were benign. Compared with older ones, patients under the age of 60 were less likely, (P < 0.001, to have incidental findings. Conclusion: Although the majority of incidental findings in this African cohort of head injury patients are benign some clinically significant lesions were detectable. It is therefore recommended that such findings be adequately described in the radiological reports for proper counseling and follow-up.

  20. Serial CT scans and Menkes' kinky hair disease

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    Nakada, Eizo; Kameyama, Junji; Yoshimitsu, Hajime; Mori, Mikio; Tanaka, Mutsuo; Yoshimitsu, Kazunori.

    1988-02-01

    Menkes' kinky hair disease is a sex-linked recessive disorder of copper metabolism, characterized by progressive psychomotor deterioration, seizures, and peculiar hair structure. We examined serial CT scans of patients with this disease. A 2,210-g male infant was delivered after an uneventful gestation of 36 weeks. His one-minute Apgar score was 9. His uncle had died at 1 year of age. His first cousin was also diagnosed as having Menkes' kinky hair disease when our patient was 2 years old. Shortly after birth he had mild respiratory distress. At 5 days of age, he developed setting-sun signs. The first CT scan, at 10 days of age, revealed mild posterior fossa hemorrhages. At 3 months of age, myoclonic seizures began, and the CT scan revealed subdural effusion and mild brain atrophy. The seizures were controllable by using phenobarbital, valproic acid, and nitrazepam. He did not follow light or a fixate, but the fundi were normal. He was diffusely hypotonic. At 9 months of age, the seizures became uncontrollable. The CT scans at 15 and 31 months of age showed subdural hemorrhage and/or brain atrophy. At 15 months of age, the serum copper level was 42 ..mu.. g/dl, while the serum ceruloplasmin level was 3.2 mg/dl. He exhibited severe developmental failure. At 4 years of age, he died.

  1. Diagnostic Utility of CT Scan for Acute Headache

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2009-08-01

    Full Text Available ED records for 364 children 2 to 5 years of age who presented to the Children’s National Medical Center ED, Washington, DC, between July 1, 2003, and June 30, 2006, with headache as their chief complaint, were examined to determine whether CT scans led to better acute management, justifying the risk of radiation.

  2. An anatomically shaped lower body model for CT scanning of cadaver femurs

    Energy Technology Data Exchange (ETDEWEB)

    Tanck, Esther; Deenen, J C W; Verdonschot, Nico [Orthopaedic Research Laboratory, Radboud University Nijmegen Medical Center, PO Box 9101, 6500 HB Nijmegen (Netherlands); Huisman, Henk Jan [Department of Radiology, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Kooloos, Jan G [Department of Anatomy, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Huizenga, Henk [Department of Radiotherapy, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands)], E-mail: e.tanck@orthop.umcn.nl

    2010-01-21

    Bone specific, CT-based finite element (FE) analyses have great potential to accurately predict the fracture risk of deteriorated bones. However, it has been shown that differences exist between FE-models of femora scanned in a water basin or scanned in situ within the human body, as caused by differences in measured bone mineral densities (BMD). In this study we hypothesized that these differences can be reduced by re-creating the patient CT-conditions by using an anatomically shaped physical model of the lower body. BMD distributions were obtained from four different femora that were scanned under three conditions: (1) in situ within the cadaver body, (2) in a water basin and (3) in the body model. The BMD of the three scanning protocols were compared at two locations: proximally, in the trabecular bone of the femoral head, and in the cortical bone of the femoral shaft. Proximally, no significant differences in BMD were found between the in situ scans and the scans in the body model, whereas the densities from the water basin scans were on average 10.8% lower than in situ. In the femoral shaft the differences between the three scanning protocols were insignificant. In conclusion, the body model better approached the in situ situation than a water basin. Future studies can use this body model to mimic patient situations and to develop protocols to improve the performance of the FE-models in actual patients. (note)

  3. Head and neck imaging with PET and PET/CT: artefacts from dental metallic implants

    Energy Technology Data Exchange (ETDEWEB)

    Goerres, Gerhard W.; Hany, Thomas F.; Kamel, Ehab; von Schulthess, Gustav K.; Buck, Alfred [Division of Nuclear Medicine, Department of Radiology, University Hospital Zurich (Switzerland)

    2002-03-01

    Germanium-68 based attenuation correction (PET{sub Ge68}) is performed in positron emission tomography (PET) imaging for quantitative measurements. With the recent introduction of combined in-line PET/CT scanners, CT data can be used for attenuation correction. Since dental implants can cause artefacts in CT images, CT-based attenuation correction (PET{sub CT}) may induce artefacts in PET images. The purpose of this study was to evaluate the influence of dental metallic artwork on the quality of PET images by comparing non-corrected images and images attenuation corrected by PET{sub Ge68} and PET{sub CT}. Imaging was performed on a novel in-line PET/CT system using a 40-mAs scan for PET{sub CT} in 41 consecutive patients with high suspicion of malignant or inflammatory disease. In 17 patients, additional PET{sub Ge68} images were acquired in the same imaging session. Visual analysis of fluorine-18 fluorodeoxyglucose (FDG) distribution in several regions of the head and neck was scored on a 4-point scale in comparison with normal grey matter of the brain in the corresponding PET images. In addition, artefacts adjacent to dental metallic artwork were evaluated. A significant difference in image quality scoring was found only for the lips and the tip of the nose, which appeared darker on non-corrected than on corrected PET images. In 33 patients, artefacts were seen on CT, and in 28 of these patients, artefacts were also seen on PET imaging. In eight patients without implants, artefacts were seen neither on CT nor on PET images. Direct comparison of PET{sub Ge68} and PET{sub CT} images showed a different appearance of artefacts in 3 of 17 patients. Malignant lesions were equally well visible using both transmission correction methods. Dental implants, non-removable bridgework etc. can cause artefacts in attenuation-corrected images using either a conventional {sup 68}Ge transmission source or the CT scan obtained with a combined PET/CT camera. We recommend that the

  4. An automatic approach for 3D registration of CT scans

    Science.gov (United States)

    Hu, Yang; Saber, Eli; Dianat, Sohail; Vantaram, Sreenath Rao; Abhyankar, Vishwas

    2012-03-01

    CT (Computed tomography) is a widely employed imaging modality in the medical field. Normally, a volume of CT scans is prescribed by a doctor when a specific region of the body (typically neck to groin) is suspected of being abnormal. The doctors are required to make professional diagnoses based upon the obtained datasets. In this paper, we propose an automatic registration algorithm that helps healthcare personnel to automatically align corresponding scans from 'Study' to 'Atlas'. The proposed algorithm is capable of aligning both 'Atlas' and 'Study' into the same resolution through 3D interpolation. After retrieving the scanned slice volume in the 'Study' and the corresponding volume in the original 'Atlas' dataset, a 3D cross correlation method is used to identify and register various body parts.

  5. Radiation Dose to the Lens of the Eye from Computed Tomography Scans of the Head

    Science.gov (United States)

    Januzis, Natalie Ann

    While it is well known that exposure to radiation can result in cataract formation, questions still remain about the presence of a dose threshold in radiation cataractogenesis. Since the exposure history from diagnostic CT exams is well documented in a patient's medical record, the population of patients chronically exposed to radiation from head CT exams may be an interesting area to explore for further research in this area. However, there are some challenges in estimating lens dose from head CT exams. An accurate lens dosimetry model would have to account for differences in imaging protocols, differences in head size, and the use of any dose reduction methods. The overall objective of this dissertation was to develop a comprehensive method to estimate radiation dose to the lens of the eye for patients receiving CT scans of the head. This research is comprised of a physics component, in which a lens dosimetry model was derived for head CT, and a clinical component, which involved the application of that dosimetry model to patient data. The physics component includes experiments related to the physical measurement of the radiation dose to the lens by various types of dosimeters placed within anthropomorphic phantoms. These dosimeters include high-sensitivity MOSFETs, TLDs, and radiochromic film. The six anthropomorphic phantoms used in these experiments range in age from newborn to adult. First, the lens dose from five clinically relevant head CT protocols was measured in the anthropomorphic phantoms with MOSFET dosimeters on two state-of-the-art CT scanners. The volume CT dose index (CTDIvol), which is a standard CT output index, was compared to the measured lens doses. Phantom age-specific CTDIvol-to-lens dose conversion factors were derived using linear regression analysis. Since head size can vary among individuals of the same age, a method was derived to estimate the CTDIvol-to-lens dose conversion factor using the effective head diameter. These conversion

  6. Analysis of the acetabulum by CT scan in Japanese with osteoarthritis of the hip

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, Masanori [Keio Univ., Tokyo (Japan). School of Medicine

    1997-11-01

    The morphology of the acetabulum was analyzed by CT scan in 66 Japanese patients with osteoarthritis of the hip mainly following congenital dislocation or dysplasia. The CT scan data was analyzed to standardize the pelvic inclination in all directions. In these patients, the acetabular floor had thickened and the acetabulum was located in the anterolateral portion. The bilateral difference in the acetabular anteversion angle was not different between patients and normal individuals, but the acetabular sector angle in patients was smaller than in the normal subjects. As the stage of osteoarthritis of the hip advanced, the thickness of the acetabular floor in the center and posterior portions and the anterior sector angle increased, and the lateralization of the acetabulum advanced, but the anteversion angle decreased. A bone-forming change is characteristic of the anterior acetabulum and acetabular fossa in the center and posterior portions in Japanese patients with osteoarthritis of the hip. In comparison with data obtained by standard radiography, these changes detected by CT scan corresponded to an increase of the width of a tear drop, the lateralization of the femoral head and the lack of the support of the femoral head from the acetabulum. (author)

  7. Brain CT scanning of children with purulent meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Mishima, M.; Suzuki, M.; Nagata, M.; Kawamura, G.

    1986-12-01

    Nine of 21 children with purulent meningitis showed abnormal findings in brain CT when admitted. All of the abnormal group were less than 12 months of age, but 75 % of the normal group were more than 1 year old. The period of positive CRP was longer and the level of sugar in CSF was lower in abnormal group when compared with normal group. Because convulsion and EEG abnormalities were observed similarly in both groups, it may be difficult to determine the organic changes of the brain clinically. Brain CT scanning is recommended as soon as possible after the onset of purulent meningitis.

  8. Segmentation of organs at risk in CT volumes of head, thorax, abdomen, and pelvis

    Science.gov (United States)

    Han, Miaofei; Ma, Jinfeng; Li, Yan; Li, Meiling; Song, Yanli; Li, Qiang

    2015-03-01

    Accurate segmentation of organs at risk (OARs) is a key step in treatment planning system (TPS) of image guided radiation therapy. We are developing three classes of methods to segment 17 organs at risk throughout the whole body, including brain, brain stem, eyes, mandible, temporomandibular joints, parotid glands, spinal cord, lungs, trachea, heart, livers, kidneys, spleen, prostate, rectum, femoral heads, and skin. The three classes of segmentation methods include (1) threshold-based methods for organs of large contrast with adjacent structures such as lungs, trachea, and skin; (2) context-driven Generalized Hough Transform-based methods combined with graph cut algorithm for robust localization and segmentation of liver, kidneys and spleen; and (3) atlas and registration-based methods for segmentation of heart and all organs in CT volumes of head and pelvis. The segmentation accuracy for the seventeen organs was subjectively evaluated by two medical experts in three levels of score: 0, poor (unusable in clinical practice); 1, acceptable (minor revision needed); and 2, good (nearly no revision needed). A database was collected from Ruijin Hospital, Huashan Hospital, and Xuhui Central Hospital in Shanghai, China, including 127 head scans, 203 thoracic scans, 154 abdominal scans, and 73 pelvic scans. The percentages of "good" segmentation results were 97.6%, 92.9%, 81.1%, 87.4%, 85.0%, 78.7%, 94.1%, 91.1%, 81.3%, 86.7%, 82.5%, 86.4%, 79.9%, 72.6%, 68.5%, 93.2%, 96.9% for brain, brain stem, eyes, mandible, temporomandibular joints, parotid glands, spinal cord, lungs, trachea, heart, livers, kidneys, spleen, prostate, rectum, femoral heads, and skin, respectively. Various organs at risk can be reliably segmented from CT scans by use of the three classes of segmentation methods.

  9. Head CT: Image quality improvement of posterior fossa and radiation dose reduction with ASiR - comparative studies of CT head examinations

    Energy Technology Data Exchange (ETDEWEB)

    Guzinski, Maciej; Waszczuk, Lukasz; Sasiadek, Marek J. [Wroclaw Medical University, Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw (Poland)

    2016-10-15

    To evaluate head CT protocol developed to improve visibility of the brainstem and cerebellum, lower bone-related artefacts in the posterior fossa and maintain patient radioprotection. A paired comparison of head CT performed without Adaptive Statistical Iterative Reconstruction (ASiR) and a clinically indicated follow-up with 40 % ASiR was acquired in one group of 55 patients. Patients were scanned in the axial mode with different scanner settings for the brain and the posterior fossa. Objective image quality analysis was performed with signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Subjective image quality analysis was based on brain structure visibility and evaluation of the artefacts. We achieved 19 % reduction of total DLP and significantly better image quality of posterior fossa structures. SNR for white and grey matter in the cerebellum were 34 % to 36 % higher, respectively, CNR was improved by 142 % and subjective analyses were better for images with ASiR. When imaging parameters are set independently for the brain and the posterior fossa imaging, ASiR has a great potential to improve CT performance: image quality of the brainstem and cerebellum is improved, and radiation dose for the brain as well as total radiation dose are reduced. (orig.)

  10. Dynamic CT head phantom for perfusion and angiography studies

    Science.gov (United States)

    Russell, K.; Blazeski, A.; Dannecker, K.; Lee, Q. Y.; Holscher, C.; Donahue, C.; van Kampen, W.

    2010-03-01

    Contrast imaging is a compelling enhancement for the portable, flat panel-based brain CT scanner currently under development at Xoran. Due to the relative low temporal resolution of flat panel detectors, enabling tomographic imaging on such platform requires optimizing the imaging and injection protocols. A dynamic CT head phantom was designed to facilitate this task. The Dynamic Perfusion and Angiography Model (PAM), mimics tissue attenuation in CT images, provides physiological timing for angiography and perfusion studies, and moves fluid with properties similar to those of blood. The design consists of an arterial system, which contains bifurcating vessels that feed into perfusion chambers, mimicking blood flow through capillaries and smaller vessels, and a venous system, which is symmetrical to the arterial side and drains the perfusion chambers. The variation of geometry and flow rate in the phantom provides the physiological total time that fluid spends in the head, and the difference in material densities correlates to CT numbers for biological tissues. This paper discusses the design of Dynamic PAM and shows experimental results demonstrating its ability to realistically simulate blood flow. Results of dynamic imaging studies of the phantom are also presented.

  11. CT scan findings of patients with Rett syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Hisaharu; Takanashi, Aiko; Hirayama, Yoshito; Sakuragawa, Norio; Arima, Masataka; Tateno, Akihiko; Koide, Hiroyoshi.

    1989-05-01

    CT findings and clinical features were analyzed in 16 female patients with Rett syndrome, whose ages were between 4 and 20. Fifteen patients had microcrania. Twelve patients were able to stand and run; however, the remaining 4 patients had the only ability to sit. CT revealed an atrophy of the ponse and various degrees of dilatation in the Silvian fissure, frontal sulcus, and space between the cranium and the frontal polar lobe. An atrophy in the frontal lobe, cerebral cortex surrounding the Silvian fissure, and white matter directly below the cortex seemed to have an important role in the occurrence of this syndrome. There was, however, no definitive correlation between the degree of atrophy and both the patient's age and motor function. Serial CT scannings with clinical process are required. (Namekawa, K).

  12. Progression of CT scan findings in Rett syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Hisaharu; Hirayama, Yoshito; Sakuragawa, Norio; Arima, Masataka (National Center of Neurology and Psychiatry, Kodaira, Tokyo (Japan))

    1989-07-01

    Progression of the lesions revealed by CT scan was observed in five girls with Rett syndrome. The most distinct and common finding was progressive dilatation of Sylvian fissures, frontal extracerebral space, interhemispheric fissure, and sulci mainly in frontal lobe. It may indicate progressive lesion in the frontal and the temporal lobes. In addition, dilatation of the anterior horns of the lateral ventricles and the third ventricle was noted in some cases. Brainstem and cerebellum were small at any age with some morphological development as the patients became elder. Neither malformations nor abnormalities in density were found in any case. It is concluded that the main lesion of Rett syndrome on CT scan is progressive and localized in the frontal and the temporal lobes. (author).

  13. Role of high resolution multislice CT scan in otosclerosis

    Directory of Open Access Journals (Sweden)

    Atef EL Maraghy

    2015-11-01

    Full Text Available This prospective study was carried out to assess the radiological findings in patients with otosclerosis using high resolution multislice CT scan and to correlate these findings with audiological findings in those patients. This study was done at Al Azhar University hospitals during the period from Jan 2012 to Jun 2014. Thirty-two patients were enrolled in this study; 13 (40.63% males and 19 (59.37% females. Their age ranged from 13 to 55 with a mean of 36.21 ± 8.7 years. Written consent was taken from all patients. Multislice CT scan was done to all patients and reports were done by computer assisted analysis with thorough audiological assessment including pure tone audiometry, tympanometry and stapedial reflex. Positive findings were present in 40/58 ears (69% while negative findings were present in 18/58 ears (31%. Otosclerotic foci were more detected when slice thickness was lesser than one millimeter especially at fissula ante fenestrum and round window region. There was a good correlation between air bone gap and CT score (p = 0.002. High resolution multislice CT helps in the diagnosis of otosclerosis with sensitivity (69% and it aids in the diagnosis of doubtful cases. Otosclerosis has a special predilection to affect certain sites mainly the fissula ante fenestrum followed by the round window and the cochlear promontory.

  14. Evaluation in the use of bismuth shielding on cervical spine CT scan using a male phantom

    Energy Technology Data Exchange (ETDEWEB)

    Aleme, C.; Mourao, A. P. [Centro Federal de Educacion Tecnologica de Minas Gerais, Biomedical Engineering Center, Belo Horizonte - MG (Brazil); Lyra, M. A., E-mail: carolinaaleme@gmail.com [Universidad Federal de Minas Gerais, Department of Nuclear Engineering, Av. Pdte. Antonio Carlos 6627, Pampulha, 31270-91 Belo Horizonte - MG (Brazil)

    2014-08-15

    The cervical spine is the region of the column that articulates the head and chest. The tests of computed tomography (CT) performed in this region have as main objectives to diagnose fractures, dislocations and tumors. In CT scans the cervical spine volume is limited by the foramen Magnum and the first thoracic vertebra. In this region is the thyroid that is directly irradiated by X-ray beam during cervical scan. Based on this information, it was studied the dose variation deposited in thyroid and in nearby organs, such as: lenses, spinal cord in the foramen Magnum region and breasts, with and without the use of bismuth protector. In this study was used a male anthropomorphic phantom and thermoluminescent s dosimeters (TLD-100) were required to register the individual doses in the organs of interest. CT scans were performed on a GE Bright Speed scanner of 32 channels. With the data obtained, it was found the organ dose variation. The largest recorded dose was in the thyroid. Comparing two scans it was possible to note that the use of the bismuth protector promoted a 26% reduction in the thyroid dose and an increase in the lens dose. (Author)

  15. Analysis of functional CT scan in cervical vertebral disease

    Energy Technology Data Exchange (ETDEWEB)

    Hirofuji, Eiichi; Tanaka, Seisuke; Tomihara, Mitsuo; Kita, Hiroshi; Yamasaki, Hiroyuki

    1982-12-01

    The atlantoaxial joint showed displacement in various directions in rheumatoid arthritis and cervical spondylosis. The displacements were promoted by anterior flexion and rotatory movements, exerting great influences on the spnial cord. The intervertebral space between the 5th and 6th vertebra showed narrowing of the vertebral canal in cervical spondylosis and was promoted by posterior flexion to affect the spinal cord to a great extent. Functional CT scan was useful for observation of pathologic conditions of vertebral diseases.

  16. Combination of CT scanning and fluoroscopy imaging on a flat-panel CT scanner

    Science.gov (United States)

    Grasruck, M.; Gupta, R.; Reichardt, B.; Suess, Ch.; Schmidt, B.; Stierstorfer, K.; Popescu, S.; Brady, T.; Flohr, T.

    2006-03-01

    We developed and evaluated a prototype flat-panel detector based Volume CT (fpVCT) scanner. The fpVCT scanner consists of a Varian 4030CB a-Si flat-panel detector mounted in a multi slice CT-gantry (Siemens Medical Solutions). It provides a 25 cm field of view with 18 cm z-coverage at the isocenter. In addition to the standard tomographic scanning, fpVCT allows two new scan modes: (1) fluoroscopic imaging from any arbitrary rotation angle, and (2) continuous, time-resolved tomographic scanning of a dynamically changing viewing volume. Fluoroscopic imaging is feasible by modifying the standard CT gantry so that the imaging chain can be oriented along any user-selected rotation angle. Scanning with a stationary gantry, after it has been oriented, is equivalent to a conventional fluoroscopic examination. This scan mode enables combined use of high-resolution tomography and real-time fluoroscopy with a clinically usable field of view in the z direction. The second scan mode allows continuous observation of a timeevolving process such as perfusion. The gantry can be continuously rotated for up to 80 sec, with the rotation time ranging from 3 to 20 sec, to gather projection images of a dynamic process. The projection data, that provides a temporal log of the viewing volume, is then converted into multiple image stacks that capture the temporal evolution of a dynamic process. Studies using phantoms, ex vivo specimens, and live animals have confirmed that these new scanning modes are clinically usable and offer a unique view of the anatomy and physiology that heretofore has not been feasible using static CT scanning. At the current level of image quality and temporal resolution, several clinical applications such a dynamic angiography, tumor enhancement pattern and vascularity studies, organ perfusion, and interventional applications are in reach.

  17. Colitis detection on abdominal CT scans by rich feature hierarchies

    Science.gov (United States)

    Liu, Jiamin; Lay, Nathan; Wei, Zhuoshi; Lu, Le; Kim, Lauren; Turkbey, Evrim; Summers, Ronald M.

    2016-03-01

    Colitis is inflammation of the colon due to neutropenia, inflammatory bowel disease (such as Crohn disease), infection and immune compromise. Colitis is often associated with thickening of the colon wall. The wall of a colon afflicted with colitis is much thicker than normal. For example, the mean wall thickness in Crohn disease is 11-13 mm compared to the wall of the normal colon that should measure less than 3 mm. Colitis can be debilitating or life threatening, and early detection is essential to initiate proper treatment. In this work, we apply high-capacity convolutional neural networks (CNNs) to bottom-up region proposals to detect potential colitis on CT scans. Our method first generates around 3000 category-independent region proposals for each slice of the input CT scan using selective search. Then, a fixed-length feature vector is extracted from each region proposal using a CNN. Finally, each region proposal is classified and assigned a confidence score with linear SVMs. We applied the detection method to 260 images from 26 CT scans of patients with colitis for evaluation. The detection system can achieve 0.85 sensitivity at 1 false positive per image.

  18. Leigh syndrome. A comparison of CT scanning and pathological findings

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Y.; Okamoto, K.; Somiya, K. (Hamamatsu Medical Center, Shizuoka (Japan)); Hokazono, Y.; Tozuka, S.

    1981-11-01

    A male infant developed hypotonia at 5 months, vomiting, diarrhea, fever, generalized clonic convulsion, tonic spasm and periodical opisthotonus at 8 months, swallowing difficulty at 10 months, pes equinovarus and optic atrophy at 11 months, and then tachypnea, and died at 14 months of age. Parents were consanguinous. Laboratory studies revealed elevated serum LDH, CPK, lactate and Pyruvate. TPP-ATP phosphoryl transferase inhibitor was negative in urine. EEG showed irregular and diffuse slow waves and periodic diffuse spike and waves. CT scan at 9 months of age showed slightly low attenuation areas in the putamen bilaterally. At 11 months, a diffuse cerebral atrophy was found, and the low attenuation of the basal ganglia became more definite. No enhanced lesion was seen at 13 months of age. Thiamine tetra-hydrofurfuryl disulfide and lipoic acid were tried without success. The pathological findings of the brain were astrogliosis and proliferation of capillaries in putamen, thalamus, caudate nucleus, substantia nigra, pontine brachium and cerebral cortex, which were symmetrically involved. The symmetrical cavitation was found in putamen. Optic nerve and mamillary body were spared. CT scan findings corresponded well with the pathology of the necrotic lesions of the brain. It was concluded that these CT scan pictures described above may be diagnostic of Leigh syndrome.

  19. Effect of CT contrast on volumetric arc therapy planning (RapidArc and helical tomotherapy) for head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Alan J.; Vora, Nayana [Department of Radiation Oncology, City of Hope National Medical Center, Duarte, CA (United States); Suh, Steve [Department of Radiation Physics, City of Hope National Medical Center, Duarte, CA (United States); Liu, An, E-mail: aliu@coh.org [Department of Radiation Physics, City of Hope National Medical Center, Duarte, CA (United States); Schultheiss, Timothy E. [Department of Radiation Physics, City of Hope National Medical Center, Duarte, CA (United States); Wong, Jeffrey Y.C. [Department of Radiation Oncology, City of Hope National Medical Center, Duarte, CA (United States)

    2015-04-01

    The objectives of the study were to evaluate the effect of intravenous contrast in the dosimetry of helical tomotherapy and RapidArc treatment for head and neck cancer and determine if it is acceptable during the computed tomography (CT) simulation to acquire only CT with contrast for treatment planning of head and neck cancer. Overall, 5 patients with head and neck cancer (4 men and 1 woman) treated on helical tomotherapy were analyzed retrospectively. For each patient, 2 consecutive CT scans were performed. The first CT set was scanned before the contrast injection and secondary study set was scanned 45 seconds after contrast. The 2 CTs were autoregistered using the same Digital Imaging and Communications in Medicine coordinates. Tomotherapy and RapidArc plans were generated on 1 CT data set and subsequently copied to the second CT set. Dose calculation was performed, and dose difference was analyzed to evaluate the influence of intravenous contrast media. The dose matrix used for comparison included mean, minimum and maximum doses of planning target volume (PTV), PTV dose coverage, and V{sub 45} {sub Gy}, V{sub 30} {sub Gy}, and V{sub 20} {sub Gy} organ doses. Treatment planning on contrasted images generally showed a lower dose to both organs and target than plans on noncontrasted images. The doses for the points of interest placed in the organs and target rarely changed more than 2% in any patient. In conclusion, treatment planning using a contrasted image had insignificant effect on the dose to the organs and targets. In our opinion, only CT with contrast needs to be acquired during the CT simulation for head and neck cancer. Dose calculations performed on contrasted images can potentially underestimate the delivery dose slightly. However, the errors of planning on a contrasted image should not affect the result in clinically significant way.

  20. Diagnosis of pituitary microadenomas by CT scan. Detection of the microadenoma by high resolution coronal scan

    Energy Technology Data Exchange (ETDEWEB)

    Sakoda, K.; Uozumi, T. (Hiroshima Univ. (Japan). School of Medicine)

    1981-10-01

    Following a detection of abnormality of pituitary hormone, it is very important to know whether the abnormality is due to pituitary microadenoma for deciding treatment methods. To diagnose pituitary microadenoma, polytomography of the sella turcica has been used. The recently developed high resolution coronal CT scan is prone to be more valuable in diagnosing microadenoma. New findings by this method were reported.

  1. Smart laser scanning sampling head design for image acquisition applications.

    Science.gov (United States)

    Amin, M Junaid; Riza, Nabeel A

    2013-07-10

    A smart laser scanning sampling head design is presented using an electronically controlled variable focal length lens to achieve the smallest sampling laser spot possible at target plane distances reaching 8 m. A proof-of-concept experiment is conducted using a 10 mW red 633 nm laser coupled with beam conditioning optics that includes an electromagnetically actuated deformable membrane liquid lens to demonstrate sampling laser spot radii under 1 mm over a target range of 20-800 cm. Applications for the proposed sampling head are diverse and include laser machining and component inspection.

  2. Complications in CT-guided Procedures: Do We Really Need Postinterventional CT Control Scans?

    Energy Technology Data Exchange (ETDEWEB)

    Nattenmüller, Johanna, E-mail: johanna.nattenmueller@med.uni-heidelberg.de; Filsinger, Matthias, E-mail: Matthias_filsinger@web.de; Bryant, Mark, E-mail: mark.bryant@med.uni-heidelberg.de; Stiller, Wolfram, E-mail: Wolfram.Stiller@med.uni-heidelberg.de; Radeleff, Boris, E-mail: boris.radeleff@med.uni-heidelberg.de; Grenacher, Lars, E-mail: lars.grenacher@med.uni-heidelberg.de; Kauczor, Hans-Ullrich, E-mail: hu.kauczor@med.uni-heidelberg.de; Hosch, Waldemar, E-mail: waldemar.hosch@urz.uni-heidelberg.de [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology (Germany)

    2013-06-19

    PurposeThe aim of this study is twofold: to determine the complication rate in computed tomography (CT)-guided biopsies and drainages, and to evaluate the value of postinterventional CT control scans.MethodsRetrospective analysis of 1,067 CT-guided diagnostic biopsies (n = 476) and therapeutic drainages (n = 591) in thoracic (n = 37), abdominal (n = 866), and musculoskeletal (ms) (n = 164) locations. Severity of any complication was categorized as minor or major. To assess the need for postinterventional CT control scans, it was determined whether complications were detected clinically, on peri-procedural scans or on postinterventional scans only.ResultsThe complication rate was 2.5 % in all procedures (n = 27), 4.4 % in diagnostic punctures, and 1.0 % in drainages; 13.5 % in thoracic, 2.0 % in abdominal, and 3.0 % in musculoskeletal procedures. There was only 1 major complication (0.1 %). Pneumothorax (n = 14) was most frequent, followed by bleeding (n = 9), paresthesia (n = 2), material damage (n = 1), and bone fissure (n = 1). Postinterventional control acquisitions were performed in 65.7 % (701 of 1,067). Six complications were solely detectable in postinterventional control acquisitions (3 retroperitoneal bleeds, 3 pneumothoraces); all other complications were clinically detectable (n = 4) and/or visible in peri-interventional controls (n = 21).ConclusionComplications in CT-guided interventions are rare. Of these, thoracic interventions had the highest rate, while pneumothoraces and bleeding were most frequent. Most complications can be detected clinically or peri-interventionally. To reduce the radiation dose, postinterventional CT controls should not be performed routinely and should be restricted to complicated or retroperitoneal interventions only.

  3. Investigating CT to CBCT image registration for head and neck proton therapy as a tool for daily dose recalculation

    Energy Technology Data Exchange (ETDEWEB)

    Landry, Guillaume, E-mail: g.landry@lmu.de [Department of Medical Physics, Ludwig-Maximilians-University, Munich D85748, Germany and Department of Radiation Oncology, Ludwig-Maximilians-University, Munich D81377 (Germany); Nijhuis, Reinoud; Thieke, Christian; Reiner, Michael; Ganswindt, Ute; Belka, Claus [Department of Radiation Oncology, Ludwig-Maximilians-University, Munich D81377 (Germany); Dedes, George; Handrack, Josefine; Parodi, Katia [Department of Medical Physics, Ludwig-Maximilians-University, Munich D85748 (Germany); Janssens, Guillaume; Orban de Xivry, Jonathan [ICTEAM, Université Catholique de Louvain, Louvain-La-Neuve B1348 (Belgium); Kamp, Florian; Wilkens, Jan J. [Department of Radiation Oncology, Technische Universität München, Klinikum rechts der Isar, Munich D81675, Germany and Physik-Department, Technische Universität München, Garching D85748 (Germany); Paganelli, Chiara; Riboldi, Marco; Baroni, Guido [Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano, Milan 20133 (Italy)

    2015-03-15

    Purpose: Intensity modulated proton therapy (IMPT) of head and neck (H and N) cancer patients may be improved by plan adaptation. The decision to adapt the treatment plan based on a dose recalculation on the current anatomy requires a diagnostic quality computed tomography (CT) scan of the patient. As gantry-mounted cone beam CT (CBCT) scanners are currently being offered by vendors, they may offer daily or weekly updates of patient anatomy. CBCT image quality may not be sufficient for accurate proton dose calculation and it is likely necessary to perform CBCT CT number correction. In this work, the authors investigated deformable image registration (DIR) of the planning CT (pCT) to the CBCT to generate a virtual CT (vCT) to be used for proton dose recalculation. Methods: Datasets of six H and N cancer patients undergoing photon intensity modulated radiation therapy were used in this study to validate the vCT approach. Each dataset contained a CBCT acquired within 3 days of a replanning CT (rpCT), in addition to a pCT. The pCT and rpCT were delineated by a physician. A Morphons algorithm was employed in this work to perform DIR of the pCT to CBCT following a rigid registration of the two images. The contours from the pCT were deformed using the vector field resulting from DIR to yield a contoured vCT. The DIR accuracy was evaluated with a scale invariant feature transform (SIFT) algorithm comparing automatically identified matching features between vCT and CBCT. The rpCT was used as reference for evaluation of the vCT. The vCT and rpCT CT numbers were converted to stopping power ratio and the water equivalent thickness (WET) was calculated. IMPT dose distributions from treatment plans optimized on the pCT were recalculated with a Monte Carlo algorithm on the rpCT and vCT for comparison in terms of gamma index, dose volume histogram (DVH) statistics as well as proton range. The DIR generated contours on the vCT were compared to physician-drawn contours on the rpCT

  4. Normal SUV values measured from NaF18- PET/CT bone scan studies.

    Directory of Open Access Journals (Sweden)

    Aung Zaw Win

    Full Text Available Cancer and metabolic bone diseases can alter the SUV. SUV values have never been measured from healthy skeletons in NaF18-PET/CT bone scans. The primary aim of this study was to measure the SUV values from normal skeletons in NaF18-PET/CT bone scans.A retrospective study was carried out involving NaF18- PET/CT bone scans that were done at our institution between January 2010 to May 2012. Our excluding criteria was patients with abnormal real function and patients with past history of cancer and metabolic bone diseases including but not limited to osteoporosis, osteopenia and Paget's disease. Eleven studies met all the criteria.The average normal SUVmax values from 11 patients were: cervical vertebrae 6.84 (range 4.38-8.64, thoracic vertebrae 7.36 (range 6.99-7.66, lumbar vertebrae 7.27 (range 7.04-7.72, femoral head 2.22 (range 1.1-4.3, humeral head 1.82 (range 1.2-2.9, mid sternum 5.51 (range 2.6-8.1, parietal bone 1.71 (range 1.3-2.4.According to our study, various skeletal sites have different normal SUV values. SUV values can be different between the normal bones and bones with tumor or metabolic bone disease. SUV can be used to quantify NaF-18 PET/CT studies. If the SUV values of the normal skeleton are known, they can be used in the characterization of bone lesions and in the assessment of treatment response to bone diseases.

  5. Role of SPECT-CT in sentinel lymph node biopsy in patients diagnosed with head and neck melanoma.

    Science.gov (United States)

    López-Rodríguez, E; García-Gómez, F J; Álvarez-Pérez, R M; Martínez-Castillo, R; Borrego-Dorado, I; Fernández-Ortega, P; Zulueta-Dorado, T

    2016-01-01

    Assess the role of SPECT-CT in sentinel lymph node (SLN) biopsy in the accurate anatomical location of the SNL in patients with cutaneous head and neck melanoma. A retrospective study was conducted from February 2010 to June 2013 on 22 consecutive patients with a diagnosis of cutaneous head and neck melanoma (9 female, 13 male), with a mean age of 55 years old and who met the inclusion criteria for SLN biopsy. Patients underwent preoperative scanning after peri-scar injection of (99m)Tc-labeled-nanocolloid. Planar images of the injection-site, whole-body, and SPECT-CT scanning were acquired. Detection rate of SLN reached up to 91% (20/22 patients) by planar lymphoscintigraphy and 95.4% (21/22 patients) by SPECT-CT. SPECT-CT provided an accurate location of SLN in 14/22 patients, enabling to improve the surgical approach (clinical impact: 63.6%). SLN was positive for metastatic cells in 9.1% patients. SPECT-CT provides detailed anatomical SLN location and allows detecting a higher number of SLN than planar lymphoscintigraphy. Routine use of SPECT-CT is recommended in order to optimise the SLN detection and location in patients with head and neck melanoma. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

  6. Soft-tissue changes after head and neck radiation: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Bronstein, A.D.; Nyberg, D.A.; Schwartz, A.N.; Shuman, W.P.; Griffin, B.R.

    1989-01-01

    To identify possible soft-tissue changes of the head and neck after radiation therapy, 102 CT scans from 78 patients with head and neck tumors were reviewed to assess (1) skin thickening, (2) epiglottic thickening, (3) stranding of subcutaneous fat, and (4) stranding of deep cervical fat. Scans were obtained after radiation therapy alone (10 cases), after radiation and surgery (27 cases), after surgery alone (24 cases), or before either surgery or radiation (41 cases). Skin thickening, epiglottic thickening, and stranding of subcutaneous fat were seen more frequently after radiation therapy than before such treatment. However, skin thickening and stranding of subcutaneous fat were sometimes also associated with tumor involvement and/or previous surgery, while epiglottic thickening was only occasionally associated with tumor involvement. Stranding of deep cervical fat was noted with increased frequency after radiation or surgery, but postradiation effects could not be reliably distinguished from postsurgical or tumor effects. We conclude that soft-tissue changes of the head and neck on CT may commonly be associated with previous radiation therapy, but these postradiation effects are not always distinguishable from postsurgical effects or tumor.

  7. Spindle cell lipoma of the head and neck: CT and MR imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Wook [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Ajou University School of Medicine, Department of Radiology, Suwon (Korea, Republic of); Kim, Hyung-Jin; Kim, Hye Jung; Cha, Ji Hoon; Kim, Sung Tae [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Kim, Jinna [Yonsei University College of Medicine, Department of Radiology, Seoul (Korea, Republic of)

    2013-01-15

    Spindle cell lipoma (SCL) is an uncommon benign lipomatous tumor, most commonly occurring in the posterior neck and shoulder. The purpose of this study was to investigate the CT and MR imaging features of SCL in the head and neck. CT (n = 5) and MR (n = 3) images of seven patients (five men and two women; mean age, 54 years) with surgically proven SCL in the head and neck were retrospectively reviewed. The location and morphologic characteristics of SCL were documented as well. Six lesions were well-defined and located in the subcutaneous fat of the posterior neck (n = 4), anterior neck (n = 1), and buccal space (n = 1). One lesion was ill-defined and located deeply in the supraclavicular fossa, infiltrating the adjacent shoulder muscles. Intratumoral fat was identified in five lesions in various amounts. Compared with the adjacent subcutaneous fat, intratumoral fat was slightly hyperattenuated on CT scans and slightly hypointense on T1-weighted MR images. In five of six lesions in which postcontrast CT and/or MR images were obtained, significant enhancement was seen in the nonadipose component of the lesion. Various components of the adipose and nonadipose tissues may cause difficulty differentiating between SCL and other adipocytic tumors including liposarcoma radiologically. Although nonspecific, the radiologist should know the various imaging features of SCL, because the tumor can be cured by simple excision. (orig.)

  8. A multicenter, randomized controlled trial of immediate total-body CT scanning in trauma patients (REACT-2

    Directory of Open Access Journals (Sweden)

    Sierink Joanne C

    2012-03-01

    Full Text Available Abstract Background Computed tomography (CT scanning has become essential in the early diagnostic phase of trauma care because of its high diagnostic accuracy. The introduction of multi-slice CT scanners and infrastructural improvements made total-body CT scanning technically feasible and its usage is currently becoming common practice in several trauma centers. However, literature provides limited evidence whether immediate total-body CT leads to better clinical outcome then conventional radiographic imaging supplemented with selective CT scanning in trauma patients. The aim of the REACT-2 trial is to determine the value of immediate total-body CT scanning in trauma patients. Methods/design The REACT-2 trial is an international, multicenter randomized clinical trial. All participating trauma centers have a multi-slice CT scanner located in the trauma room or at the Emergency Department (ED. All adult, non-pregnant, severely injured trauma patients according to predefined criteria will be included. Patients in whom direct scanning will hamper necessary cardiopulmonary resuscitation or who require an immediate operation because of imminent death (both as judged by the trauma team leader are excluded. Randomization will be computer assisted. The intervention group will receive a contrast-enhanced total-body CT scan (head to pelvis during the primary survey. The control group will be evaluated according to local conventional trauma imaging protocols (based on ATLS guidelines supplemented with selective CT scanning. Primary outcome will be in-hospital mortality. Secondary outcomes are differences in mortality and morbidity during the first year post trauma, several trauma work-up time intervals, radiation exposure, general health and quality of life at 6 and 12 months post trauma and cost-effectiveness. Discussion The REACT-2 trial is a multicenter randomized clinical trial that will provide evidence on the value of immediate total-body CT scanning

  9. Computed tomographic (CT) scans in cerebral palsy (CP)

    Energy Technology Data Exchange (ETDEWEB)

    Kolawole, T.M.; Patel, P.J. (King Saud Univ., Riyadh (Saudi Arabia). Dept. of Radiology); Mahdi, A.H. (King Saud Univ., Riyadh (Saudi Arabia). Dept. of Paediatrics)

    1989-11-01

    The CT findings in 120 cerebral palsied children are analysed. The 72.5% positive findings are correlated with the clinical types, as well as the aetiological basis for the cerebral palsy. The spastic type, 83.3% of the total number of children, had the highest positive findings. The yield was increased in children with seizures (91.3%) and those in the postnatal group (90%), as well as those with birth trauma and neonatal asphyxia (94%). The findings were those of atrophy in 30.8%, hydrocephalus, in 10%, infarct in 11.6%, porencephaly in 8.3% and others. The atropic changes and their patterns are explained. Treatable lesions, such as tumour, hydrocephalus, subdural haematoma, porencephaly and hygroma were identified in 22.5% of cases. It is concluded that CT scan is definitely efficacious in the management of cerebral palsied children. (orig.).

  10. Treatment of alzheimer disease with CT scans - a case report

    Energy Technology Data Exchange (ETDEWEB)

    Cuttler, J.M. [Cuttler & Associates Inc., Vaughan, Ontario (Canada); Moore, E.R. [Dow Chemical Co., Midland, MI (United States); Hosfeld, V.D. [MidMichigan Health, Midland, MI (United States); Nadolski, D.L. [Midland Internal Medicine Associates PC, Midland, MI (United States)

    2016-03-15

    Alzheimer disease (AD) primarily affects older adults. This neurodegenerative disorder is the most common cause of dementia and is a leading source of their morbidity and mortality. U.S. patient care costs are about 200 billion dollars and will more than double by 2040. This case report describes the remarkable improvement of an advanced AD patient in hospice, who received five CT scans of the brain, about 40 mGy each, over a period of three months. The mechanism appears to be radiation-induced up-regulation of the patient's adaptive protection systems against AD, which partially restored cognition, memory, speech, movement, and appetite. (author)

  11. Reducing radiation dose in adult head CT using iterative reconstruction. A clinical study in 177 patients

    Energy Technology Data Exchange (ETDEWEB)

    Kaul, D. [Charite School of Medicine and University Hospital, Berlin (Germany). Dept. of Radiology; Charite School of Medicine and University Hospital, Berlin (Germany). Dept. of Radiation Oncology; Kahn, J.; Huizing, L.; Wiener, E.; Grupp, U.; Boening, G.; Streitparth, F. [Charite School of Medicine and University Hospital, Berlin (Germany). Dept. of Radiology; Ghadjar, P. [Charite School of Medicine and University Hospital, Berlin (Germany). Dept. of Radiation Oncology; Renz, D.M. [Jena University Hospital (Germany). Dept. of Radiology

    2016-02-15

    To assess how ASIR (adaptive statistical iterative reconstruction) contributes to dose reduction and affects image quality of non-contrast cranial computed tomography (cCT). Non-contrast emergency CT scans of the head acquired in 177 patients were evaluated. The scans were acquired and processed using four different protocols: Group A (control): 120 kV, FBP (filtered back projection) n=71; group B1: 120 kV, scan and reconstruction performed with 20 % ASIR (blending of 20 % ASIR and 80 % FBP), n=86; group B2: raw data from group B1 reconstructed using a blending of 40 % ASIR and 60 % FBP, n=74; group C1: 120 kV, scan and reconstruction performed with 30 % ASIR, n=20; group C2: raw data from group C1 reconstructed using a blending of 50 % ASIR and 50 % FBP, n=20. The effective dose was calculated. Image quality was assessed quantitatively and qualitatively. Compared to group A, groups B1/2 and C1/2 showed a significantly reduced effective dose of 40.4 % and 73.3 % (p < 0.0001), respectively. Group B1 and group C1/2 also showed significantly reduced quantitative and qualitative image quality parameters. In group B2, quantitative measures were comparable to group A, and qualitative scores were lower compared to group A but higher compared to group B1. Diagnostic confidence grading showed groups B1/2 to be adequate for everyday clinical practice. Group C2 was considered acceptable for follow-up imaging of severe acute events such as bleeding or subacute stroke. Conclusion: Use of ASIR makes it possible to reduce radiation significantly while maintaining adequate image quality in non-contrast head CT, which may be particularly useful for younger patients in an emergency setting and in follow-up.

  12. SU-F-SPS-03: Direct Measurement of Organ Doses Resulting From Head and Cervical Spine Trauma CT Protocols

    Energy Technology Data Exchange (ETDEWEB)

    Carranza, C; Lipnharski, I; Quails, N; Correa, N; Rill, L; Arreola, M [University of Florida, Gainesville, FL (United States)

    2016-06-15

    Purpose: This retrospective study analyzes the exposure history of emergency department (ED) patients undergoing head and cervical spine trauma computed tomography (CT) studies. This study investigated dose levels received by trauma patients and addressed any potential concerns regarding radiation dose issues. Methods: Under proper IRB approval, a cohort of 300 trauma cases of head and cervical spine trauma CT scans received in the ED was studied. The radiological image viewing software of the hospital was used to view patient images and image data. The following parameters were extracted: the imaging history of patients, the reported dose metrics from the scanner including the volumetric CT Dose Index (CTDIvol) and Dose Length Product (DLP). A postmortem subject was scanned using the same scan techniques utilized in a standard clinical head and cervical spine trauma CT protocol with 120 kVp and 280 mAs. The CTDIvol was recorded for the subject and the organ doses were measured using optically stimulated luminescent (OSL) dosimeters. Typical organ doses to the brain, thyroid, lens, salivary glands, and skin, based on the cadaver studies, were then calculated and reported for the cohort. Results: The CTDIvol reported by the CT scanner was 25.5 mGy for the postmortem subject. The average CTDIvol from the patient cohort was 34.1 mGy. From these metrics, typical average organ doses in mGy were found to be: Brain (44.57), Thyroid (33.40), Lens (82.45), Salivary Glands (61.29), Skin (47.50). The imaging history of the cohort showed that on average trauma patients received 26.1 scans over a lifetime. Conclusion: The average number of scans received on average by trauma ED patients shows that radiation doses in trauma patients may be a concern. Available dose tracking software would be helpful to track doses in trauma ED patients, highlighting the importance of minimizing unnecessary scans and keeping doses ALARA.

  13. The use of brain CT Scan in craniocerebral trauma with Glasgow coma scale scores of 13 – 15 in Dr. Cipto Mangunkusumo Hospital 1999-2001

    Directory of Open Access Journals (Sweden)

    Jofizal Jannis

    2004-09-01

    Full Text Available There is still a controversy among the neurologists whether brain CT scan must be performed on the mild head trauma patients. This study was executed to find out the correlation between the brain CT scan image findings and its clinical impairment among the mild head trauma patients with Glasgow coma scale (GCS score of 13 to 15. The study was a retrospective study by analyzing the uniform medical records of the head trauma patients hospitalized at the Neurology ward of Dr. Cipto Mangunkusumo Hospital within the period of 1999 to 2001. During that period 1,663 patients were hospitalized due to head trauma, and 1,166 of them (70.1 % were suffered from mild head trauma patients with GCS score of 13-15. Among those with brain CT scan examinations (N: 271, the neurological abnormalities were found on 144 (53.1% of patients, consisted of cerebral edema (11,4%, intracerebral hemorrhage (5.5%, epidural hemorrhage (16.2%, subdural hemorrhage (18.1%, subarachnoid hemorrhage (5.5%, and combination (13.8%. The further analysis showed that cranial nerves disturbance, amnesia, loss of conciousness for more than 10 minutes, and vomiting are significantly correlated to the brain CT scan abnormality. Combination of the above four clinical signs and symptoms have sensitivity of 90 % in predicting brain insults. This findings may be used as a simple set of clinical criteria for identifying mild head trauma patients who need undergo CT scan examination. (Med J Indones 2004; 13: 156-60 Keywords: mild head injury, brain CT scan

  14. Light scattering in optical CT scanning of Presage dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y; Adamovics, J; Cheeseborough, J C; Chao, K S; Wuu, C S, E-mail: yx2010@columbia.ed

    2010-11-01

    The intensity of the scattered light from the Presage dosimeters was measured using a Thorlabs PM100D optical power meter (Thorlabs Inc, Newton, NJ) with an optical sensor of 1 mm diameter sensitive area. Five Presage dosimeters were made as cylinders of 15.2 cm, 10 cm, 4 cm diameters and irradiated with 6 MV photons using a Varian Clinac 2100EX. Each dosimeter was put into the scanning tank of an OCTOPUS' optical CT scanner (MGS Research Inc, Madison, CT) filled with a refractive index matching liquid. A laser diode was positioned at one side of the water tank to generate a stationary laser beam of 0.8 mm width. On the other side of the tank, an in-house manufactured positioning system was used to move the optical sensor in the direction perpendicular to the outgoing laser beam from the dosimeters at an increment of 1 mm. The amount of scattered photons was found to be more than 1% of the primary light signal within 2 mm from the laser beam but decreases sharply with increasing off-axis distance. The intensity of the scattered light increases with increasing light attenuations and/or absorptions in the dosimeters. The scattered light at the same off-axis distance was weaker for dosimeters of larger diameters and for larger detector-to-dosimeter distances. Methods for minimizing the effect of the light scattering in different types of optical CT scanners are discussed.

  15. Head-to-head comparison between {sup 18}F-FDOPA PET/CT and MR/CT angiography in clinically recurrent head and neck paragangliomas

    Energy Technology Data Exchange (ETDEWEB)

    Heimburger, Celine; Hubele, Fabrice; Namer, Izzie Jacques [University Hospitals of Strasbourg, Department of Biophysics and Nuclear Medicine, Strasbourg (France); CNRS/University of Strasbourg, ICube, UMR 7357, Strasbourg (France); University of Strasbourg, FMTS, Faculty of Medicine, Strasbourg (France); Veillon, Francis; Riehm, Sophie; Cavalcanti, Marcela [University Hospitals of Strasbourg, Department of Radiology, Strasbourg (France); Taieb, David [Aix-Marseille University, Department of Nuclear Medicine, La Timone University Hospital, Marseille (France); Aix-Marseille University, European Center for Research in Medical Imaging, Marseille (France); Institut Paoli-Calmettes, Inserm UMR1068 Marseille Cancerology Research Center, Marseille (France); Goichot, Bernard; Chabrier, Gerard [University Hospitals of Strasbourg, Department of Internal Medicine, Strasbourg (France); Petit-Thomas, Julie; Charpiot, Anne [University Hospitals of Strasbourg, Department of Otolaryngology and Maxillofacial Surgery, Strasbourg (France); Averous, Gerlinde [University Hospitals of Strasbourg, Department of Pathology, Strasbourg (France); Imperiale, Alessio [University Hospitals of Strasbourg, Department of Biophysics and Nuclear Medicine, Strasbourg (France); CNRS/University of Strasbourg, ICube, UMR 7357, Strasbourg (France); University of Strasbourg, FMTS, Faculty of Medicine, Strasbourg (France); Hautepierre University Hospital, Biophysics and Nuclear Medicine, Strasbourg Cedex (France)

    2017-06-15

    Head and neck paragangliomas (HNPGLs) can relapse after primary treatment. Optimal imaging protocols have not yet been established for posttreatment evaluation. The aim of the present study was to assess the diagnostic value of {sup 18}F-FDOPA PET/CT and MR/CT angiography (MRA/CTA) in HNPGL patients with clinical relapse during their follow-up. Sixteen consecutive patients presenting with local pain, tinnitus, dysphagia, hoarse voice, cranial nerve involvement, deafness, or retrotympanic mass appearing during follow-up after the initial treatment of HNPGLs were retrospectively evaluated. Patients underwent both {sup 18}F-FDOPA PET/CT and MRA (15 patents) or CTA (1 patent). Both methods were first assessed under blinded conditions and afterwards correlated. Head and neck imaging abnormalities without histological confirmation were considered true-positive results based on a consensus between radiologists and nuclear physicians and on further {sup 18}F-FDOPA PET/CT and/or MRA. {sup 18}F-FDOPA PET/CT and MRA/CTA were concordant in 14 patients and in disagreement in 2 patients. {sup 18}F-FDOPA PET/CT and MRA/CTA identified, respectively, 12 and 10 presumed recurrent HNPGLs in 12 patients. The two lesions diagnosed by PET/CT only were confirmed during follow-up by otoscopic examination and MRA performed 29 and 17 months later. {sup 18}F-FDOPA PET/CT images were only slightly influenced by the posttreatment sequelae, showing a better interobserver reproducibility than MRA/CTA. Finally, in 2 of the 16 studied patients, {sup 18}F-FDOPA PET/CT detected two additional synchronous primary HNPGLs. {sup 18}F-FDOPA PET/CT is highly sensitive in posttreatment evaluation of patients with HNPGLs, and also offers better interobserver reproducibility than MRA/CTA and whole-body examination. We therefore suggest that {sup 18}F-FDOPA PET/CT is performed as the first diagnostic imaging modality in symptomatic patients with suspicion of HNPGL relapse after primary treatment when {sup 68

  16. Head movement during CT brain perfusion acquisition of patients with suspected acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Fahmi, F., E-mail: f.fahmi@amc.uva.nl [Department of Biomedical Engineering and Physics, AMC, Amsterdam (Netherlands); Beenen, L.F.M., E-mail: l.f.beenen@amc.uva.nl [Department of Radiology, AMC, Amsterdam (Netherlands); Streekstra, G.J., E-mail: g.j.streekstra@amc.uva.nl [Department of Biomedical Engineering and Physics, AMC, Amsterdam (Netherlands); Janssen, N.Y., E-mail: n.n.janssen@amc.uva.nl [Department of Biomedical Engineering and Physics, AMC, Amsterdam (Netherlands); Jong, H.W. de, E-mail: H.W.A.M.deJong@umcutrecht.nl [Department of Radiology, UMC Utrecht, 3584CX, Utrecht (Netherlands); Riordan, A., E-mail: alan.riordan@gmail.com [Department of Radiology, UMC Utrecht, 3584CX, Utrecht (Netherlands); Roos, Y.B., E-mail: y.b.roos@amc.uva.nl [Department of Neurology, AMC, Amsterdam (Netherlands); Majoie, C.B., E-mail: c.b.majoie@amc.uva.nl [Department of Radiology, AMC, Amsterdam (Netherlands); Bavel, E. van, E-mail: e.vanbavel@amc.uva.nl [Department of Biomedical Engineering and Physics, AMC, Amsterdam (Netherlands); Marquering, H.A., E-mail: h.a.marquering@amc.uva.nl [Department of Biomedical Engineering and Physics, AMC, Amsterdam (Netherlands); Department of Radiology, AMC, Amsterdam (Netherlands)

    2013-12-01

    Objective: Computed Tomography Perfusion (CTP) is a promising tool to support treatment decision for acute ischemic stroke patients. However, head movement during acquisition may limit its applicability. Information of the extent of head motion is currently lacking. Our purpose is to qualitatively and quantitatively assess the extent of head movement during acquisition. Methods: From 103 consecutive patients admitted with suspicion of acute ischemic stroke, head movement in 220 CTP datasets was qualitatively categorized by experts as none, minimal, moderate, or severe. The movement was quantified using 3D registration of CTP volume data with non-contrast CT of the same patient; yielding 6 movement parameters for each time frame. The movement categorization was correlated with National Institutes of Health Stroke Scale (NIHSS) score and baseline characteristic using multinomial logistic regression and student's t-test respectively. Results: Moderate and severe head movement occurred in almost 25% (25/103) of all patients with acute ischemic stroke. The registration technique quantified head movement with mean rotation angle up to 3.6° and 14°, and mean translation up to 9.1 mm and 22.6 mm for datasets classified as moderate and severe respectively. The rotation was predominantly in the axial plane (yaw) and the main translation was in the scan direction. There was no statistically significant association between movement classification and NIHSS score and baseline characteristics. Conclusions: Moderate or severe head movement during CTP acquisition of acute stroke patients is quite common. The presented registration technique can be used to automatically quantify the movement during acquisition, which can assist identification of CTP datasets with excessive head movement.

  17. Radiation exposure from pediatric head CT: a bi-institutional study

    Energy Technology Data Exchange (ETDEWEB)

    King, Mary A. [University of Washington, Department of Pediatrics, Harborview Medical Center, Seattle, WA (United States); Seattle Children' s Hospital, Seattle, WA (United States); Kanal, Kalpana M.; Relyea-Chew, Annemarie [University of Washington, Department of Radiology, Harborview Medical Center, Seattle, WA (United States); Bittles, Mark [Vanderbilt Children' s Hospital, Department of Radiology, Nashville, TN (United States); Vavilala, Monica S. [University of Washington, Departments of Anesthesiology and Pediatrics, Harborview Medical Center, 325 Ninth Avenue, Box 359724, Seattle, WA (United States); Hollingworth, William [University of Bristol, Department of Social Medicine, Bristol (United Kingdom)

    2009-10-15

    Medical radiation from CT should be kept as low as reasonably achievable (ALARA), particularly in young patients. To examine radiation dose from head CT in children in a trauma center (TC) and a regional children's hospital (RCH). A random sample of 240 children (0-3, 4-9, 10-14 years of age) from the TC were compared with a similar cohort from the RCH. All children had undergone at least one head CT scan without contrast enhancement; data from PACS and Department of Radiology Information System were used to estimate normalized effective dose (ED). Lifetime attributable risk of cancer incidence was estimated using the Biologic Effects of Ionizing Radiation (BEIR) VII report. The mean normalized ED was significantly higher in the youngest children at the TC (2.74 mSv in those aged 0-3 years vs. 2.23 mSv in those aged 10-14 years; P<0.001) and at the RCH (2.44 mSv in those aged 0-3 years vs. 1.71 mSv in those aged 10-14 years; P<0.001). Each decreasing year of age was independently associated with a 0.06 mSv higher mean normalized ED (P<0.001). After adjusting for the age difference between the institutions, the mean normalized ED was 0.44 mSv lower at the RCH than at the TC across all ages (95% CI 0.31-0.58, P<0.001). A higher lifetime attributable risk of cancer was associated with younger age. The radiation dose from head CT in children as defined by the normalized ED was highest in the youngest children and varied significantly between institutions in this bi-institutional study. (orig.)

  18. Multiplanar CT assessment of femoral head displacement in slipped capital femoral epiphysis

    Energy Technology Data Exchange (ETDEWEB)

    Monazzam, Shafagh [Rady Children' s Hospital and Health Center, Department of Orthopedics, San Diego, CA (United States); Dwek, Jerry R. [Rady Children' s Hospital and Health Center, Department of Radiology, San Diego, CA (United States); Hosalkar, Harish S. [Center for Hip Preservation, Department of Orthopedic Surgery, TriCity Medical Center, Oceanside, CA (United States)

    2013-12-15

    With recent changing approaches to the management of slipped capital femoral epiphysis (SCFE), the accurate radiographic assessment of maximum extent of displacement is crucial for planning surgical treatment. To determine what plane best represents the maximum SCFE displacement as quantified by the head-neck angle difference (HNAD), whether HNAD can quantitatively differentiate the SCFE cohort from the normal cohort, based on CT, and how Southwick slip angle (SSA) compares to HNAD. We reviewed 19 children with SCFE (23 affected hips) with preoperative CT scans and 27 age- and sex-matched children undergoing abdominal CT for non-orthopedic problems. Head-neck angle (HNA), the angle between the femoral epiphysis and the neck axis, was measured in three planes on each hip and the HNAD (affected - unaffected hip) was determined. SSA was measured on radiographs. The coronal HNAD (mean 8.7 ) was less than both the axial-oblique (mean 30.7 ) and sagittal (mean 37.4 ) HNADs, which were also greater than the HNADs of the normal cohort. Grouping HNAD measurements by SSA severity classification did not consistently distinguish between SCFE severity levels. Axial-oblique and sagittal planes best represent the maximum SCFE displacement while biplanar radiograph may underestimate the extent of the displacement, thereby potentially altering the management between in situ pinning and capital realignment. (orig.)

  19. Acoustic property reconstruction of a neonate Yangtze finless porpoise's (Neophocaena asiaeorientalis) head based on CT imaging.

    Science.gov (United States)

    Wei, Chong; Wang, Zhitao; Song, Zhongchang; Wang, Kexiong; Wang, Ding; Au, Whitlow W L; Zhang, Yu

    2015-01-01

    The reconstruction of the acoustic properties of a neonate finless porpoise's head was performed using X-ray computed tomography (CT). The head of the deceased neonate porpoise was also segmented across the body axis and cut into slices. The averaged sound velocity and density were measured, and the Hounsfield units (HU) of the corresponding slices were obtained from computed tomography scanning. A regression analysis was employed to show the linear relationships between the Hounsfield unit and both sound velocity and density of samples. Furthermore, the CT imaging data were used to compare the HU value, sound velocity, density and acoustic characteristic impedance of the main tissues in the porpoise's head. The results showed that the linear relationships between HU and both sound velocity and density were qualitatively consistent with previous studies on Indo-pacific humpback dolphins and Cuvier's beaked whales. However, there was no significant increase of the sound velocity and acoustic impedance from the inner core to the outer layer in this neonate finless porpoise's melon.

  20. Decreasing the effective radiation dose in pediatric craniofacial CT by changing head position

    Energy Technology Data Exchange (ETDEWEB)

    Didier, Ryne A. [Oregon Health and Science University, School of Medicine, Portland, OR (United States); Kuang, Anna A. [Oregon Health and Science University, Department of Plastic and Reconstructive Surgery, Portland, OR (United States); Schwartz, Daniel L. [Oregon Health and Science University, Department of Psychiatry, Portland, OR (United States); Selden, Nathan R. [Oregon Health and Science University, Department of Neurological Surgery, Portland, OR (United States); Stevens, Donna M. [Oregon Health and Science University, Department of Diagnostic Radiology, Portland, OR (United States); Bardo, Dianna M.E. [Oregon Health and Science University, Department of Diagnostic Radiology, Portland, OR (United States); Oregon Health and Science University, Department of Neuroradiology, Portland, OR (United States)

    2010-12-15

    Children are exposed to ionizing radiation during pre- and post-operative evaluation for craniofacial surgery. The primary purpose of the study was to decrease effective radiation dose while preserving the diagnostic quality of the study. In this prospective study 49 children were positioned during craniofacial CT (CFCT) imaging with their neck fully extended into an exaggerated sniff position, parallel to the CT gantry, to eliminate the majority of the cervical spine and the thyroid gland from radiation exposure. Image-quality and effective radiation dose comparisons were made retrospectively in age-matched controls (n = 49). When compared to CT scans reviewed retrospectively, the prospective examinations showed a statistically significant decrease in z-axis length by 16% (P < 0.0001) and delivered a reduced effective radiation dose by 18% (P < 0.0001). The subjective diagnostic quality of the exams performed in the prospective arm was maintained despite a slight decrease in the quality of the brain windows. There was statistically significant improvement in the quality of the bone windows and three-dimensional reconstructed images. Altering the position of the head by extending the neck during pediatric craniofacial CT imaging statistically reduces the effective radiation dose while maintaining the diagnostic quality of the images. (orig.)

  1. Evaluation of Radiation Dose Reduction during CT Scans Using Oxide Bismuth and Nano-Barium Sulfate Shields

    CERN Document Server

    Seoung, Youl-Hun

    2015-01-01

    The purpose of the present study was to evaluate radiation dose reduction and image quality during CT scanning by using a new dose reduction fiber sheet (DRFS) with commercially available bismuth shields. These DRFS were composed of nano-barium sulfate (BaSO4), filling the gaps left by the large oxide bismuth (Bi2O3) particle sizes. The radiation dose was measured five times at directionss of 12 o'clock from the center of the polymethyl methacrylate (PMMA) head phantom to calculate an average value using a CT ionization chamber. The image quality measured CT transverse images of the PMMA head phantom depending on X-ray tube voltages and the type of shielding. Two regions of interest in CT transverse images were chosen from the right and left areas under the surface of the PMMA head phantom and from ion chamber holes located at directions of 12 o'clock from the center of the PMMA head phantom. The results of this study showed that the new DRFS shields could reduce dosages to 15.61%, 23.05%, and 22.71% more in ...

  2. Quality assurance of CT scanning for industrial applications

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch

    ClassWeb through volume comparisons to real dissections of pig carcasses. For the real dissections, volumes of tissue types such as bone, lean meat and fat, are estimated using commercial VolumeGraphics software. It is detected that the ANOVA and the residuals from the virtual dissection fail the normality test...... to 158 μm, compared to average uncertainties below 5.5 μm using CMMs. A test was performed to check if X-ray contrast modalities can be applied for metrological purposes. Traditionally, segmentation between multi-materials in CT scanning is done by using different edge detection techniques and threshold...... to 1348 mL, compared to average uncertainties below 10 mL using the gravimetric method. DMRI and DTU Compute have previously developed advanced image analysis software (PigClassWeb) which performs virtual dissections in pig carcasses. A DOE was carried out to document the performance of Pig...

  3. 基于256层螺旋CT头颈部扫描的最优辐射剂量节省模式的实验研究%The experimental study of optimal radiation dosage saving mode based on the scan of head and neck using 256-slice CT

    Institute of Scientific and Technical Information of China (English)

    马恩森; 马国林; 王武; 任安

    2013-01-01

    目的 探讨在保证影像质量前提下的头颈部256层CT最优低剂量节省模式.方法 应用组织等效头颈部模型置于Philips Brilliance256层CT机以标准模式(400mAs)和低剂量节省模式进行分别扫描,其中低剂量节省模式包括自动管电流选择(ACS)、螺旋剂量节省(Helical Dose Saving)、X-Y平面动态电流调节(D-DOM)、Z轴动态电流调节技术(Z-DOM)等进行组合,测量、记录模型蝶鞍、下颌骨和胸骨柄各部位CT值、CT值噪声标准差(SD),分别行方差分析.结果 共有8种组合模式可降低辐射剂量.即:①ACS;②ACS+ Helical;③ACS+ (D-DOM);④ACS+ (Z-DOM);⑤ACS+ Helical +(D-DOM);⑥ACS+ (D-DOM)+ (Z-DOM);⑦ACS+ Helical--(Z-DOM);③ACS+ Helical+ (D-DOM)+(Z-DOM).与标准剂量CTDI26.5mGy,DLP1276.8 mGy* cm相比,CT不同剂量节省方式扫描时,在保证图像质量的同时,辐射剂量可节省11.21%~68.12%.采用最优剂量节省模式ACS+ Helical+(D-DOM)+(Z-DOM),CTDI从26mGy降低到11.8mGy,DLP从1134.6mGy* cm降低到504.9mGy* cm.蝶鞍、下颌骨和胸骨柄水平相同部位软组织和骨骼的CT值在各组间差异均无统计学意义(P≥0.05).蝶鞍、下颌骨水平骨骼结构测量的SD值有统计学差别(P<0.01),而胸骨柄水平骨骼SD值和蝶鞍、下颌骨、胸骨柄水平相同部位软组织SD值间差异均无统计学意义(P>0.05).结论 在头颈部螺旋CT扫描中,恰当运用螺旋CT剂量节省模式,辐射剂量可大大降低.%Objective To investigate the optimal low dose 256-slice CT scan mode of the head and neck on the promise to ensure image quality. Methods A head and neck phantom equivalent to human tissue was scaned by Philips Brilliance 256 slice-CT at standard dose(400 mAs)and low dose saving mode scanning, the low-dose saving mode includes automatic current selection (ACS), helical dose saving, dynamic angular dose modulation (D-DOM), Z-axis dose modulation (Z-DOM), and the combination of the above mode. The CT

  4. Intrapartum FHR monitoring and neonatal CT brain scan

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Yoshiki; Ukita, Masahiko; Nakada, Eizo (Kurashiki Central Hospital, Okayama (Japan))

    1982-12-01

    The effect of fetal distress on the neonatal brain was investigated by neonatal CT brain scan, FHR monitoring and mode of delivery. This study involved 11 cases of full term vertex delivery in which FHR was recorded by fetal direct ECG during the second stage labor. All infants weighed 2,500 g or more. FHR monitoring was evaluated by Hon's classification. Neonatal brain edema was evaluated by cranial CT histgraphic analysis (Nakada's method). 1) Subdural hemorrhage was noted in 6 of 7 infants delivered by vacuum extraction or fundal pressure (Kristeller's method). 2) Intracranial hemorrhage was demonstrated in all of 3 infants with 5-min. Apgar score 7 or less. 3) Two cases with prolonged bradycardia and no variability had intraventricular or intracerebral hemorrhage which resulted in severe central nervous system damage. 4) The degree of neonatal brain edema correlated with 5-min. Apgar score. 5) One case with prolonged bradycardia and no variability resulted in severe neonatal brain edema. Four cases with variable deceleration and increased variability resulted in mild neonatal brain edema. Two cases with late deceleration and decreased variability resulted in no neonatal brain edema.

  5. Clinical evaluation of dynamic CT scan of the pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Tokuda, Masamichi

    1984-09-01

    The clinical usefulness of dynamic CT scans (DCT) of the pancreas was evaluated in 62 normal cases, 9 cases of acute pancreatitis, 24 cases of chronic pancreatitis and 43 cases of carcinoma of the pancreas. The normal pancreas was intensely and homogeneously enhanced on DCT, and peripancreatic vessels were clearly demonstrated, especially the gastroduodenal artery (98.4%). DCT was useful to demonstrate vascular lesions, associated with pancreatitis such as pseudoaneurysm. Although the carcinoma of the pancreas showed poor contrast enhancement on conventional enhanced CT (CCT), 37.2% showed intense contrast enhancement on DCT. Visualization of the gastroduodenal artery by DCT is helpful to decide the extent of tumor. DCT is superior to CCT in demonstrating collateral veins caused by tumor invasion to the portal system in carcinoma. DCT was approximately as accurate as angiography (92.6%) in evaluating tumor invasion to the portal system. DCT is a useful and minimally invasive modality in assessing the resectability of pancreatic carcinoma. DCT may eliminate angiography and surgery in unresectable cases. (author).

  6. Validation of CT brain perfusion methods using a realistic dynamic head phantom

    NARCIS (Netherlands)

    Riordan, A.J.; Prokop, M.; Viergever, M.A.; Dankbaar, J.W.; Smit, E.J.; Jong, H.W. de

    2011-01-01

    PURPOSE: Development and evaluation of a realistic hybrid head phantom for the validation of quantitative CT brain perfusion methods. METHODS: A combination, or hybrid, of CT images of an anthropomorphic head phantom together with clinically acquired MRI brain images was used to construct a dynamic

  7. A study of the short- to long-phantom dose ratios for CT scanning without table translation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xinhua; Zhang, Da; Liu, Bob, E-mail: bliu7@mgh.harvard.edu [Division of Diagnostic Imaging Physics, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114 and Webster Center for Advanced Research and Education in Radiation, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Yang, Jie [Pinnacle Health - Fox Chase Regional Cancer Center, Harrisburg, Pennsylvania 17109 (United States)

    2014-09-15

    Purpose: For CT scanning in the stationary-table modes, AAPM Task Group 111 proposed to measure the midpoint dose on the central and peripheral axes of sufficiently long phantoms. Currently, a long cylindrical phantom is usually not available in many clinical facilities. The use of a long phantom is also challenging because of the heavy weight. In order to shed light on assessing the midpoint dose in CT scanning without table movement, the authors present a study of the short- to long-phantom dose ratios, and perform a cross-comparison of CT dose ratios on different scanner models. Methods: The authors performed Geant4-based Monte Carlo simulations with a clinical CT scanner (Somatom Definition dual source CT, Siemens Healthcare), and modeled dosimetry measurements using a 0.6 cm{sup 3} Farmer type chamber and a 10-cm long pencil ion chamber. The short (15 cm) to long (90 cm) phantom dose ratios were computed for two PMMA diameters (16 and 32 cm), two phantom axes (the center and the periphery), and a range of beam apertures (3–25 cm). The results were compared with the published data of previous studies with other multiple detector CT (MDCT) scanners and cone beam CT (CBCT) scanners. Results: The short- to long-phantom dose ratios changed with beam apertures but were insensitive to beam qualities (80–140 kV, the head and body bowtie filters) and MDCT and CBCT scanner models. Conclusions: The short- to long-phantom dose ratios enable medical physicists to make dosimetry measurements using the standard CT dosimetry phantoms and a Farmer chamber or a 10 cm long pencil chamber, and to assess the midpoint dose in long phantoms. This method provides an effective approach for the dosimetry of CBCT scanning in the stationary-table modes, and is useful for perfusion and interventional CT.

  8. CT evaluation of solitary pulmonary nodule : value of additional HRCT scan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeung Sook; Kwak Jin Young; Lee, Seung Ik; Ha, Doo Hoe [Pundang CHA General Hospital, Pochon CHA Univ. College of Medicine, Sungnam (Korea, Republic of); Kim, Tae Sung; Hwang, Jung Hwa; Lee, Kyung Soo [Samsung Medical Center, Sungkyunkwan Univ. College of Medicine, Seoul (Korea, Republic of); Kim, Yook Yung [Ewha Womans Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-04-01

    The aim of our study was to evaluate the usefulness of high-resolution CT scans in addition to helical CT for characterizing a solitary pulmonary nodule. Our study included 49 patients with a solitary pulmonary nodule ; in each patient this was evaluated by both additional high-resolution CT and helical scanning. Images were evaluated by three independent observers, each of whom read them twice : initially with helical CT images only and then with helical images plus high-resolution CT images. After analysis, the observers recorded the following : histologic diagnosis, benignancy or malignancy of a nodule, and confidence in their diagnosis (three scales). In differentiating benign and malignant nodules, the accuracy of helical scans only was 75% (110/147 readings) whereas that of helical plus high-resolution CT scans was 82% (121/147 readings)({rho}=0.001). Correct histologic diagnosis was made in 47% of cases (69/147 readings) when helical scans only had been evaluated and in 48% of cases (71/147 readings) for which both helical and high-resolotion CT scans were available ({rho}=0.815). Diagnosis was more often highly confident on the basis of additional high-resolution CT scans (25%) than helical scans only (5%) ({rho}=0.001). By enhancing differential diagnostic accuracy between benign and malignant nodules and by increasing confidence in the histologic diagnosis of a pulmonary nodule, additional high-resolution CT scans are valuable for the evaluation of a solitary pulmonary nodule.

  9. Cardiac CT angiography after coronary artery surgery in children using 64-slice CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Marini, Davide; Agnoletti, Gabriella [Centre de Reference Malformations Cardiaques Congenitales Complexes-M3C, Universite Paris Descartes, UFR Necker-Enfants Malades, Paris (France); Brunelle, Francis [University Paris Descartes, UFR Necker-Enfants Malades, Department of Pediatric Radiology, APHP, Paris (France); Sidi, Daniel; Bonnet, Damien [Centre de Reference Malformations Cardiaques Congenitales Complexes-M3C, Universite Paris Descartes, UFR Necker-Enfants Malades, Paris (France); Ou, Phalla [Centre de Reference Malformations Cardiaques Congenitales Complexes-M3C, Universite Paris Descartes, UFR Necker-Enfants Malades, Paris (France); University Paris Descartes, UFR Necker-Enfants Malades, Department of Pediatric Radiology, APHP, Paris (France)], E-mail: phalla.ou@nck.aphp.fr

    2009-09-15

    Objective: The purpose of this study was to compare the diagnostic accuracy of 64-slice CT with that of invasive angiography in the detection of graft and/or coronary angioplasty stenosis in children who had undergone coronary artery surgery. Population and methods: Fifteen consecutive children (8 male and 7 female; age 9.2 {+-} 6.1 years) underwent 64-slice CT because of chest pain or ECG changes mean 4.8 {+-} 3.7 years after surgical coronary artery surgery; 10 patients had coronary angioplasty using a patch from the saphenous vein, four had mammary artery bypass, and one had saphenous vein bypass. Six main segments of the coronary arteries and all the bypass graft considered as a single segment were analyzed and compared with invasive angiography used as the reference standard. Results: CT correctly identified the four children with coronary angioplasty and mammary graft lesions that were confirmed by conventional angiography: one patient had a significant stenosis (>50% stenosis) at the mammary bypass graft anastomosis site; three other had non-significant stenosis (<50% stenosis) including a mild lesion of the saphenous vein patch in two patients and a mild lesion at the anastomosis site of the mammary bypass in one. All segments identified as normal by CT in the other 11 children were also found to be normal by conventional angiography. Conclusion: In centers expert in this technique, 64-slice CT scanning is a promising, rapid, and useful diagnostic technique for evaluating both coronary angioplasty and bypass graft lesions in children who had undergone coronary artery surge0008.

  10. Not a NICE CT protocol for the acutely head injured child

    Energy Technology Data Exchange (ETDEWEB)

    Willis, A.P.; Latif, S.A.A.; Chandratre, S.; Stanhope, B. [Birmingham Children' s Hospital, Steelhouse Lane, Birmingham, B4 6NH (United Kingdom); Johnson, K. [Birmingham Children' s Hospital, Steelhouse Lane, Birmingham, B4 6NH (United Kingdom)], E-mail: karl.johnson@bch.nhs.uk

    2008-02-15

    Aim: To assess the impact of the introduction of the Birmingham Children's Hospital (BCH) head injury computed tomography (CT) guidelines, when compared with the National Institute of Health and Clinical Excellence (NICE) guidelines, on the number of children with head injuries referred from the Emergency Department (ED) undergoing a CT examination of the head. Material and methods: All children attending BCH ED over a 6-month period with any severity of head injury were included in the study. ED case notes were reviewed and data were collected on a specifically designed proforma. Indications for a CT examination according to both NICE and BCH head injury guidelines and whether or not CT examinations were performed were recorded. Results: A total of 1428 children attended the BCH ED following a head injury in the 6-month period. The median age was 4 years (range 6 days to 15 years) and 65% were boys. Four percent of children were referred for a CT using BCH guidelines and were appropriately examined. If the NICE guidelines had been strictly adhered to a further 8% of children would have undergone a CT examination of the head. All of these children were discharged without complication. The remaining 88% had no indication for CT examination by either BCH or NICE and appropriately did not undergo CT. Conclusions: Adherence to the NICE head injury guidelines would have resulted in a three-fold increase in the total number of CT examinations of the head. The BCH head injury guidelines are both safe and appropriate in the setting of a large children's hospital experienced in the management of children with head injuries.

  11. Childhood CT scans linked to leukemia and brain cancer later in life

    Science.gov (United States)

    Children and young adults scanned multiple times by computed tomography (CT), a commonly used diagnostic tool, have a small increased risk of leukemia and brain tumors in the decade following their first scan.

  12. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT scanning procedure. For exams (excluding head and neck) your head will remain outside the hole in ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: ...

  13. Dual-time FDG-PET/CT in patients with potential breast cancer recurrence: Head-to-head comparison with CT and bone scintigraphy

    DEFF Research Database (Denmark)

    Baun, Christina; Falch Braas, Kirsten; Gerke, Oke

    Dual-time FDG-PET/CT in patients with potential breast cancer recurrence: Head-to-head comparison with CT and bone scintigraphy  Kirsten Falch, Christina Baun, Oke Gerke, , Ziba A. Farahani, Poul F. Høilund-Carlsen, Lisbet B. Larsen*, Marianne Ewertz**, Katrine Søe*** and Malene G. Hildebrandt...... Departments of Nuclear Medicine, *Radiology, **Oncolocy, and ***Surgery, Odense University Hospital, Odense, Denmark Purpose: Breast cancer (BC) is the most common type of cancer among women in Denmark and about 1/3 of the affected women experience recurrence. The prognosis is good if loco regional recurrence...... FDG PET/CT, routine bone scintigraphy and CT of the chest and upper abdomen within 2 weeks. Patients with other malignancies, pregnant or lactating women, patients younger than 18 years and patients with confirmed metastatic disease were not eligible FDG PET/CT. All patients fasted for a minimum...

  14. Evaluating applicability of metal artifact reduction algorithm for head and neck radiation treatment planning CT

    Energy Technology Data Exchange (ETDEWEB)

    Son, Sang Jun; Park, Jang Pil; Kim, Min Jeong; Yoo, Suk Hyun [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-06-15

    The purpose of this study is evaluation for the applicability of O-MAR(Metal artifact Reduction for Orthopedic Implants)(ver. 3.6.0, Philips, Netherlands) in head and neck radiation treatment planning CT with metal artifact created by dental implant. All of the in this study's CT images were scanned by Brilliance Big Bore CT(Philips, Netherlands) at 120 kVp, 2 mm sliced and Metal artifact reduced by O-MAR. To compare the original and reconstructed CT images worked on RTPS(Eclipse ver 10.0.42, Varian, USA). In order to test the basic performance of the O-MAR, The phantom was made to create metal artifact by dental implant and other phantoms used for without artifact images. To measure a difference of HU in with artifact images and without artifact images, homogeneous phantom and inhomogeneous phantoms were used with cerrobend rods. Each of images were compared a difference of HU in ROIs. And also, 1 case of patient's original CT image applied O-MAR and density corrected CT were evaluated for dose distributions with SNC Patient(Sun Nuclear Co., USA). In cases of head and neck phantom, the difference of dose distribution is appeared 99.8% gamma passing rate(criteria 2 mm / 2%) between original and CT images applied O-MAR. And 98.5% appeared in patient case, among original CT, O-MAR and density corrected CT. The difference of total dose distribution is less than 2% that appeared both phantom and patient case study. Though the dose deviations are little, there are still matters to discuss that the dose deviations are concentrated so locally. In this study, The quality of all images applied O-MAR was improved. Unexpectedly, Increase of max. HU was founded in air cavity of the O-MAR images compare to cavity of the original images and wrong corrections were appeared, too. The result of study assuming restrained case of O-MAR adapted to near skin and low density area, it appeared image distortion and artifact correction simultaneously. In O-MAR CT, air cavity area

  15. Centre for Industrial Application of CT scanning (CIA-CT) – Four years of results 2009-2013

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Andreasen, Jan Lasson; Christensen, Lars Bager;

    as a centre of excellence for industrial CT scanning, both nationally and internationally. A network with approx. 40 participants has been established, and a total of 22 students have been educated. Dissemination activities have encompassed: a web page www.cia-ct.mek.dtu.dk , 8 newsletters, 4 topical...

  16. Clinical Applications of FDG PET and PET/CT in Head and Neck Cancer

    Directory of Open Access Journals (Sweden)

    Akram Al-Ibraheem

    2009-01-01

    Full Text Available 18F-FDG PET plays an increasing role in diagnosis and management planning of head and neck cancer. Hybrid PET/CT has promoted the field of molecular imaging in head and neck cancer. This modality is particular relevant in the head and neck region, given the complex anatomy and variable physiologic FDG uptake patterns. The vast majority of 18F-FDG PET and PET/CT applications in head and neck cancer related to head and neck squamous cell carcinoma. Clinical applications of 18F-FDG PET and PET/CT in head and neck cancer include diagnosis of distant metastases, identification of synchronous 2nd primaries, detection of carcinoma of unknown primary and detection of residual or recurrent disease. Emerging applications are precise delineation of the tumor volume for radiation treatment planning, monitoring treatment, and providing prognostic information. The clinical role of 18F-FDG PET/CT in N0 disease is limited which is in line with findings of other imaging modalities. MRI is usually used for T staging with an intense discussion concerning the preferable imaging modality for regional lymph node staging as PET/CT, MRI, and multi-slice spiral CT are all improving rapidly. Is this review, we summarize recent literature on 18F-FDG PET and PET/CT imaging of head and neck cancer.

  17. [CT/MRI image characteristics of iliopsoas bursitis in avascular necrosis of femoral head].

    Science.gov (United States)

    Gong, Ennian; Jia, Baoliang; Shi, Zhichao; Zhou, Liping; Xu, Guojuan; Tian, Zaichao

    2008-03-01

    To investigate the spectrum of CT and MR imaging and surgical operation findings in iliopsoas bursitis in patients with avascular necrosis of femoral head so as to enhance the diagnostic ability. A total of 1,415 patients with avascular necrosis of the femoral head were analyzed retrospectively; of them, 15 patients were complicated by iliopsoas bursitis surgically or aspiration of synovial fluid between May 2005 and May 2007. Fifteen cases were all necrosis of the bilateral femoral head and 17 hips were combined with iliopsoas bursitis. There were 14 males and 1 female, aging 29-58 years. The course of disease was 1 month to 3 years. All 15 patients had limitation of ability of the hips and the "4" type sign was positive. The Harris score of hip's function was 54-78 (mean 62.7). Five patients of them can be touched a palpable cystic mass and tenderness in the inguinal area, and 3 of them associated with femoral neuropathy and 2 patients presented slight atrophy of the thigh muscle in suffering side. All these cases were taken X-ray films of positive and frog-leg lateral position, helical CT scan with 5 mm thinness, and MRI was performed in 6 patients with TlWI, T2WI, T2WI and fat-saturated inversion recovery sequence. The radiographs were the primary basis evidences for diagnosis and degrees of the avascular necrosis of femoral head. According to the standards of Association Research Circulation Osseuse, there were 2 hips at stage II (II C 2), 6 hips at stage III ( II B 1, III C 5 and 9 hips at stage IV. The X-ray films showed the bulging of the fat pad and soft tissue swelling in 6 patients. CT analysis disclosed that the enlarged iliopsoas bursae appeared as hypodense, well-defined, thin-walled (bursitis presented as low signal on T1WI and water-like high signal on T2WI and markedly higher signal on STIR in 6 cases. The demonstration of the extent, size, mass effects and its relation and subsequent affection to surrounding anatomical structures were clearly

  18. Improving CT scan capabilities with a new trauma workflow concept: Simulation of hospital logistics using different CT scanner scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Fung Kon Jin, P.H.P., E-mail: p.fungkonjin@amc.uva.nl [Trauma Unit Department of Surgery, Academic Medical Center, Amsterdam (Netherlands); Dijkgraaf, M.G.W., E-mail: m.dijkgraaf@amc.uva.nl [Department of Clinical Epidemiology, Biostatistics, and Bioinformatics, Academic Medical Center, Amsterdam (Netherlands); Alons, C.L., E-mail: clalons@few.vu.nl [Department of Mathematics, VU University Amsterdam, Amsterdam (Netherlands); Kuijk, C. van, E-mail: c.vankuijk@vumc.nl [Department of Radiology, VU Medical Center, Amsterdam (Netherlands); Beenen, L.F.M., E-mail: l.beenen@amc.uva.nl [Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Koole, G.M., E-mail: koole@few.vu.nl [Department of Mathematics, VU University Amsterdam, Amsterdam (Netherlands); Goslings, J.C., E-mail: j.c.goslings@amc.uva.nl [Trauma Unit Department of Surgery, Academic Medical Center, Amsterdam (Netherlands)

    2011-11-15

    Introduction: The Amsterdam Trauma Workflow (ATW) concept includes a sliding gantry CT scanner serving two mirrored (trauma) rooms. In this study, several predefined scenarios with a varying number of CT scanners and CT locations are analyzed to identify the best performing patient flow management strategy from an institutional perspective on process quality. Materials and methods: A total of six clinically relevant scenarios with variables that included the number of CT scanners, CT scanner location, and different patient categories (regular, urgent, and trauma patients) were evaluated using computer simulation. Each scenario was simulated using institutional data and was assessed for patient waiting times, idle time of CT scanners, and overtime due to scheduling. The best 2- and 3-scanner scenarios were additionally evaluated with the ATW-concept. Results: Based on institutional data, the best 2-scanner scenario distributes all 3 patient categories over both scanners and plans 4 urgent patients per hour while locating both scanners outside of the trauma room. The best 3-scanner scenario distributes urgent and regular patients over all 3 scanners and trauma patients on only 1 scanner and locates all CT scanners outside of the trauma room. The ATW concept reduces waiting times and overtime, while increasing idle time. Conclusion: Choosing the optimal planning and distribution strategies depends on the number and location of available CT scanners, along with number of trauma, urgent and regular patients. The Amsterdam Trauma Workflow concept could provide institutions with the ability of early CT scanning in trauma patients without influencing regular and urgent CT scanning.

  19. Total-body CT scanning in trauma patients: Benefits and boundaries

    NARCIS (Netherlands)

    Sierink, J.C.

    2015-01-01

    Computed tomography (CT) scanning has become essential in the early diagnostic phase of trauma care. It is a fast and highly accurate modality for the identification of various injuries and it enables a rapid response to life-threatening problems. Especially total-body CT (TBCT) scanning is increasi

  20. The diagnostic value of PET/CT scanning in patients with cervical cancer

    DEFF Research Database (Denmark)

    Loft, Annika; Berthelsen, Anne Kiil; Roed, Henrik

    2007-01-01

    OBJECTIVE: To investigate the clinical value of PET/CT as a supplement to FIGO staging in patients with cervical cancer stage >or=1B. METHODS: This prospective study included 120 consecutive patients. After staging, a whole-body PET/CT scan was performed and these examinations were divided into two....../CT scanning for newly diagnosed cervical cancer FIGO stage >or=1B has a high sensitivity and specificity, and can be a valuable supplement to the FIGO staging procedure....

  1. Open source deformable image registration system for treatment planning and recurrence CT scans

    DEFF Research Database (Denmark)

    Zukauskaite, Ruta; Brink, Carsten; Hansen, Christian Rønn

    2016-01-01

    manually contoured eight anatomical regions-of-interest (ROI) twice on pCT and once on rCT. METHODS: pCT and rCT images were deformably registered using the open source software elastix. Mean surface distance (MSD) and Dice similarity coefficient (DSC) between contours were used for validation of DIR...... on pCT. DSC for DIR varied between 0.58 and 0.79 for soft tissues and was 0.79 or higher for bony structures, and correlated with the volumes of ROIs (r = 0.5, p elastix in HNSCC on planning and recurrence CT scans is feasible...

  2. 18F-Fluorodeoxyglucose-PET/CT in locally advanced head and neck cancer can influence the stage migration and nodal radiation treatment volumes.

    Science.gov (United States)

    Mazzola, Rosario; Alongi, Pierpaolo; Ricchetti, Francesco; Fiorentino, Alba; Fersino, Sergio; Giaj-Levra, Niccolò; Salgarello, Matteo; Alongi, Filippo

    2017-08-28

    To analyze the impact of 18F-fluorodeoxyglucose-PET/CT (PET/CT) in the radiotherapy (RT) planning strategy in HNC, correlating CT-scan and PET/CT performances. Inclusion criteria were: age >18 years old, histologically proven head and neck cancer (HNC), patients candidate to definitive RT ± chemotherapy, stage of disease by means of PET/TC and CT-scan performed at our Cancer Care Center. Sixty patients were analyzed. The following primary tumor sites were investigated: nasopharynx (13%), oropharynx (42%), oral cavity (32%) and larynx non-glottic (13%). Globally, PET/CT findings caused changes on nodal radiation treatment volumes in 10% of all the population of study. Specifically, in 5 cases out of 19 oral cavity tumors (26%), PET/CT detected neck-nodes positive (not detected at CT-scan). These findings have allowed to change the patients management, including PET/CT neck-nodes positive in the high-risk RT volumes. In the RT planning strategy, the present findings support the use of PET/CT to improve upfront regional staging of HNC disease, particularly for oral cavity tumors. Further investigations are advocated to evaluate if this strategy could impact on long-term outcomes in terms of local control and overall survival.

  3. Migratory birds use head scans to detect the direction of the earth's magnetic field.

    Science.gov (United States)

    Mouritsen, Henrik; Feenders, Gesa; Liedvogel, Miriam; Kropp, Wiebke

    2004-11-09

    Night-migratory songbirds are known to use a magnetic compass , but how do they detect the reference direction provided by the geomagnetic field, and where is the sensory organ located? The most prominent characteristic of geomagnetic sensory input, whether based on visual patterns or magnetite-mediated forces , is the predicted symmetry around the north-south or east-west magnetic axis. Here, we show that caged migratory garden warblers perform head-scanning behavior well suited to detect this magnetic symmetry plane. In the natural geomagnetic field, birds move toward their migratory direction after head scanning. In a zero-magnetic field , where no symmetry plane exists, the birds almost triple their head-scanning frequency, and the movement direction after a head scan becomes random. Thus, the magnetic sensory organ is located in the bird's head, and head scans are used to locate the reference direction provided by the geomagnetic field.

  4. A new method of CT scanning for the diagnosis of mandibular fractures; A preliminary report: diagnosis of condyle fractures

    Energy Technology Data Exchange (ETDEWEB)

    Tsukagoshi, Taku; Satoh, Kaneshige; Onizuka, Takuya (Showa Univ., Tokyo (Japan). School of Medicine)

    1990-08-01

    The condylar neck of the mandible is one of the most common fracture sites in the facial skeleton. Such a fracture is routinely diagnosed by A-P, lateral oblique, and Towne projection roentgenography or orthopantomography. Despite the combination of these films, fracture of the neck of the mandible is still difficult to diagnose definitely. Therefore, a new CT scanning method was developed for diagnosing fractures of the neck of the condylar mandible. The CT axis is projected along the length of the mandible, extending from the condyle to the symphysis. This projection visualizes both the condyle and the mandibular symphysis in the same plane. The patient is placed in a supine position with the head fully extended. The base line, a line extending from the midpoint of the glenoid fossa to the menton, is determined with a lateral facial cephalogram. CT scanning with a 5 mm window is performed in parallel with and 2 cm anterior to and 2 cm posterior to the base line. When CT scanning was performed in a healthy volunteer, the condition of the condyle and the condylar neck of the mandible was clearly shown, and the view extended from the condyle to the symphysis. For automobile accident patients in whom fracture of the neck of the mandible was associated with fracture of the symphysis, two fractures were found in the same plane. A newly developed CT scanning technique is useful in the diagnosis of fractures of the condylar neck of the mandible and in the identification of fractures at other mandibular sites. It also allows scanning of patients in a supine position, which may aid in managing patients with multiple traumas. (N.K.).

  5. Optimized Temporal Window for Detection and Characterization of Renal Cell Carcinomas with Dynamic CT Scanning

    Institute of Scientific and Technical Information of China (English)

    Jinhong Wang; Peijun Wang; Xiaohu Zhao; Xinqin Mao; Xiaolong Gao; Jun Liu

    2005-01-01

    OBJECTIVE To investigate the optimized time period for detection and characterization of renal cell carcinomas (RCC) when the specific CT features appear during spiral dynamic CT scanning, and to optimize an effective scanning protocol of spiral CT for evaluating RCC.METHODS Twenty-four patients with RCC verified by pathology had undergone a dynamic CT (D-CT) scan. A plain scan was employed to select the target slice. Single-level dynamic scanning started at 14-17 s after the intravenous contrast media had been administered, with a scan interval of 4.9 s acquiring a total number of 17~24 frames. A regular CT scan of the whole kidney followed by a delayed single slice acquisition through the target slice in the excretory phase was performed. Images were assessed in two ways: (1) A group of experienced radiologists reviewed the CT images to find when the specific signs appeared and when the CT features of RCC were optimally displayed; (2) Data measurement of the time-density curves (T-DC) of RCC. The exact time was obtained when the densities of the tumor, renal parenchyma, medulla and aorta reached their peak enhancement, thus also the time when the density difference between tumor and parenchyma was at maximum (Max T-M). Based on the slope of the contrast media uptake curve, T-DC types were ranked from the smallest to the biggest of slope as type A, B and C.RESULTS 1. The review of the CT images by the radiologists showed that the CT features of RCC were optimally demonstrated at 70.2 s. The earliest time at which RCC CT features were examined was at 23.9 s. 2. Image data analysis: the time that the density (or CT value) of the tumor mass reached peak enhancement was at 54 s and peak value was at 80.4 Hu for RCC. The time of the maximal difference of densities between tumor and renal parenchyma was at 102 s.CONCLUSION The following proposal is the scanning protocol for detecting RCC recommended by our research: After a plain scan to determine the target level, a

  6. Spinal CT scan, 2. Lumbar and sacral spines

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Hiroshi (Aichi Medical Univ., Aichi (Japan))

    1982-08-01

    Plain CT described fairly accurately the anatomy and lesions of the lumbar and sacral spines on their transverse sections. Since hernia of the intervertebral disc could be directly diagnosed by CT, indications of myelography could be restricted. Spinal-canal stenosis of the lumbar spine occurs because of various factors, and CT not only demonstrated the accurate size and morphology of bony canals, but also elucidated thickening of the joints and yellow ligament. CT was also useful for the diagnosis of tumors in the lumbar and sacral spines, visualizing the images of bone changes and soft tissues on the trasverse sections. But the diagnosis of intradural tumors required myelography and metrizamide CT. CT has become important for the diagnosis of spinal and spinal-cord diseases and for selection of the route of surgical arrival.

  7. Course and variation of the intercostal artery by CT scan.

    Science.gov (United States)

    Helm, Emma J; Rahman, Najib M; Talakoub, Omid; Fox, Danial L; Gleeson, Fergus V

    2013-03-01

    It is conventionally taught that the intercostal artery is shielded in the intercostal groove of the superior rib. The continuous course and variability of the intercostal artery, and factors that may influence them, have not been described in a large number of arteries in vivo. Maximal intensity projection reformats in the coronal plane were produced from CT scan pulmonary angiograms to identify the posterolateral course of the intercostal artery (seventh to 11th rib spaces). A novel semiautomated computer segmentation algorithm was used to measure distances between the lower border of the superior rib, the upper border of the inferior rib, and the position of the intercostal artery when exposed in the intercostal space. The position and variability of the artery were analyzed for association with clinical factors. Two hundred ninety-eight arteries from 47 patients were analyzed. The mean lateral distance from the spine over which the artery was exposed within the intercostal space was 39 mm, with wide variability (SD, 10 mm; 10th-90th centile, 28-51 mm). At 3 cm lateral distance from the spine, 17% of arteries were shielded by the superior rib, compared with 97% at 6 cm. Exposed artery length was not associated with age, sex, rib space, or side. The variability of arterial position was significantly associated with age (coefficient, 0.91; P intercostal artery is exposed within the intercostal space in the first 6 cm lateral to the spine. The variability of its vertical position is greater in older patients and in more cephalad rib spaces.

  8. Value of the post-operative CT in predicting delayed flap failures following head and neck cancer surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bitna; Yoon, Dae Young; Seo, Young Lan; Park, Min Woo; Kwon, Kee Hwan; Rho, Young Soo; Chung, Chul Hoon [Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of)

    2017-06-15

    To identify post-operative computed tomography (CT) findings associated with delayed flap failures following head and neck cancer surgery. We retrospectively reviewed 60 patients who underwent flap reconstruction after head and neck cancer surgery and post-operative (3–14 days) contrast-enhanced CT scans for suspected complications. Patients were divided into two groups: delayed flap failure patients (patients required flap revision) (n = 18) and flap success patients (n = 42). Clinical data (age, sex, T-stage, type of flap, and time interval between reconstruction surgery and CT) and post-operative CT findings of flap status (maximum dimension of the flap, intra- or peri-flap fluid collection and intra- or peri-flap air collection, fat infiltration within the flap, fistula to adjacent aerodigestive tract or skin, and enhanced vascular pedicle) were assessed and compared between the two groups. CT findings showed that the following flap anomalies were observed more frequently in the delayed flap failure group than in the flap success group: intra- or peri-flap fluid collection > 4 cm (61.1% vs. 23.8%, p < 0.05), intra- or peri-flap air collection > 2 cm (61.1% vs. 2.4%, p < 0.001), and fistula to adjacent aerodigestive tract or skin (44.4% vs. 0%, p < 0.001). The maximum dimension of the flap, fat infiltration within the flap, and enhanced vascular pedicle were not associated with delayed flap failures. A large amount of fluid or air collection and fistula are the CT findings that were associated with delayed flap failures in patients with suspected post-operative complications after head and neck cancer surgery.

  9. Cervical spine evaluation in urban trauma centers: lowering institutional costs and complications through helical CT scan.

    Science.gov (United States)

    Grogan, Eric L; Morris, John A; Dittus, Robert S; Moore, Derek E; Poulose, Benjamin K; Diaz, Jose J; Speroff, Theodore

    2005-02-01

    In the evaluation of the cervical spine (c-spine), helical CT scan has higher sensitivity and specificity than plain radiographs in the moderate- and high-risk trauma population, but is more costly. We hypothesize that institutional costs associated with missed injuries make helical CT scan the least costly approach. A cost-minimization study was performed using decision analysis examining helical CT scan versus radiographic evaluation of the c-spine. Parameter estimates were obtained from the literature for probability of c-spine injury, probability of paralysis after missed injury, plain film sensitivity and specificity, CT scan sensitivity and specificity, and settlement cost of missed injuries resulting in paralysis. Institutional costs of CT scan and plain radiography were used. Sensitivity analyses tested robustness of strategy preference, accounted for parameter variability, and determined threshold values for individual parameters on strategy preference. C-spine evaluation with helical CT scan has an expected cost of US 554 dollars per patient compared with US 2,142 dollars for plain films. CT scan is the least costly alternative if threshold values exceed US 58,180 dollars for institutional settlement costs, 0.9% for probability of c-spine fracture, and 1.7% for probability of paralysis. Plain films are least costly if CT scan costs surpass US 1,918 dollars or plain film sensitivity exceeds 90%. Helical CT scan is the preferred initial screening test for detection of cervical spine fractures among moderate- to high-risk patients seen in urban trauma centers, reducing the incidence of paralysis resulting from false-negative imaging studies and institutional costs, when settlement costs are taken into account.

  10. Vascular anatomy of the liver and porta hepatis with dynamic CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Hiramatsu, Yoshihiro; Wada, Mitsuyoshi; Nakajima, Teiichi; Tonooka, Reiko; Matsumoto, Kunihiko

    1983-01-01

    Vascular anatomy of the liver and porta heaptis demonstrated by dynamic CT scan was studied Identification of the individual vessels was sometimes difficult due to slight differencies in respiratory depths among the scans. Limitation in the number of slices also made the evalution of the vascular anatomy difficult. Angiography was therefore utilized for comparison in identifying the vessels. Dynamic CT scan was proved to be usefull in demonstrating the anteroposterior relationship of the vessels and surrounding structures, which is difficult with convetional angiography without multiple projections. Three dimensional understanding of the vessels was then possible with dynamic CT scan and angiography. When combined with recently advancing digital subtraction angiography, dynamic CT scan might reduce the necessity for conventional angiography with Seldinger's technique. (author).

  11. The relevance of MRI for patient modeling in head and neck hyperthermia treatment planning: A comparison of CT and CT-MRI based tissue segmentation on simulated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Verhaart, René F., E-mail: r.f.verhaart@erasmusmc.nl; Paulides, Margarethus M. [Hyperthermia Unit, Department of Radiation Oncology, Erasmus MC - Cancer Institute, Groene Hilledijk 301, Rotterdam 3008 AE (Netherlands); Fortunati, Valerio; Walsum, Theo van; Veenland, Jifke F. [Biomedical Imaging Group of Rotterdam, Department of Medical Informatics and Radiology, Erasmus MC, Dr. Molewaterplein 50/60, Rotterdam 3015 GE (Netherlands); Verduijn, Gerda M. [Department of Radiation Oncology, Erasmus MC - Cancer Institute, Groene Hilledijk 301, Rotterdam 3008 AE (Netherlands); Lugt, Aad van der [Department of Radiology, Erasmus MC, Dr. Molewaterplein 50/60, Rotterdam 3015 GE (Netherlands)

    2014-12-15

    Purpose: In current clinical practice, head and neck (H and N) hyperthermia treatment planning (HTP) is solely based on computed tomography (CT) images. Magnetic resonance imaging (MRI) provides superior soft-tissue contrast over CT. The purpose of the authors’ study is to investigate the relevance of using MRI in addition to CT for patient modeling in H and N HTP. Methods: CT and MRI scans were acquired for 11 patients in an immobilization mask. Three observers manually segmented on CT, MRI T1 weighted (MRI-T1w), and MRI T2 weighted (MRI-T2w) images the following thermo-sensitive tissues: cerebrum, cerebellum, brainstem, myelum, sclera, lens, vitreous humor, and the optical nerve. For these tissues that are used for patient modeling in H and N HTP, the interobserver variation of manual tissue segmentation in CT and MRI was quantified with the mean surface distance (MSD). Next, the authors compared the impact of CT and CT and MRI based patient models on the predicted temperatures. For each tissue, the modality was selected that led to the lowest observer variation and inserted this in the combined CT and MRI based patient model (CT and MRI), after a deformable image registration. In addition, a patient model with a detailed segmentation of brain tissues (including white matter, gray matter, and cerebrospinal fluid) was created (CT and MRI{sub db}). To quantify the relevance of MRI based segmentation for H and N HTP, the authors compared the predicted maximum temperatures in the segmented tissues (T{sub max}) and the corresponding specific absorption rate (SAR) of the patient models based on (1) CT, (2) CT and MRI, and (3) CT and MRI{sub db}. Results: In MRI, a similar or reduced interobserver variation was found compared to CT (maximum of median MSD in CT: 0.93 mm, MRI-T1w: 0.72 mm, MRI-T2w: 0.66 mm). Only for the optical nerve the interobserver variation is significantly lower in CT compared to MRI (median MSD in CT: 0.58 mm, MRI-T1w: 1.27 mm, MRI-T2w: 1.40 mm

  12. CT scan evaluation of glenoid bone and pectoralis major tendon: interest in shoulder prosthesis

    Science.gov (United States)

    Obert, Laurent; Peyron, Christelle; Boyer, Etienne; Menu, Gauthier; Loisel, François; Aubry, Sébastien

    2016-01-01

    Introduction: The shoulder arthroplasty brings satisfaction to patients in terms of quality of life and indolence. However whether anatomic implant or reverse, it does not escape from the loosening of the glenoid component. Moreover, optimal implantation is required to ensure the functional outcome without shortening of the arm. The purpose of this study is obtain CT scan evaluation of the glenoid bone stock in order to optimize glenoid component implantation and obtain a reference to determine optimal humeral component placement in case of humeral proximal fracture. Materials and methods: Between 2010 and 2011 we have analyzed 200 intact shoulder’s CT. We measured maximal and minimal width in the transverse plane of the glenoid, the distance from the pectoralis major (PM) tendon to the humeral head, the greater tubercle, change of curvature and the anatomical neck. Results: Mean maximum width was 27.4 ± 3.4 mm and mean minimum width was 15.5 ± 2.8 mm. Distances between upper edge of PM tendon to: humeral head, greater tubercle, change of curvature and anatomical neck were respectively: 67.6 ± 9.98 mm, 57.8 ± 10.3 mm, 28.7 ± 9 mm, and 34.2 ± 9.7 mm. Conclusion: Our study has produced an assessment of glenoid bone stock for optimal positioning of the glenoid implant but also to obtain a reference to determine the ideal location of the humeral component in the case of proximal humerus fracture. PMID:27716461

  13. Is It Possible to Predict Heart Rate and Range during Enhanced Cardiac CT Scan from Previous Non-enhanced Cardiac CT?

    OpenAIRE

    Horiguchi, Jun; Yamamoto, Hideya; Arie, Ryuichi; Kiguchi, Masao; Fujioka, Chikako; Ohtaki, Megu; Kihara, Yasuki; Awai, Kazuo

    2010-01-01

    The effect of heart rate and variation during cardiac computed tomography (CT) on the examination quality. The purpose of this study is to investigate whether it is possible to predict heart rate and range during enhanced cardiac computed CT scan from previous non-enhanced cardiac CT scan. Electrocardiograph (ECG) files from 112 patients on three types of cardiac 64-slice CT (non-enhanced, prospective ECG-triggered and retrospective ECG-gated enhanced scans) were recorded. The mean heart rate...

  14. Brain tumors and CT scan in infants and children, (1). The impact on pediatric neuroradiology

    Energy Technology Data Exchange (ETDEWEB)

    Ohi, S.; Velasco, J.M. (Northwestern Univ., Chicago, IL (USA). Medical School)

    1980-10-01

    The dramatic change in the neuroradiological procedures have been noted after CT scan was introduced in the last several years. Remarkable decreasing numbers of angiographic, pneumoencephalographic and other invasive neuroradiologic studies as well as nuclear brain scan were also found in the pediatric neuroradiology. The authors analyzed the total numbers of these studies performed in the last several years in pediatric neurological/neurosurgical practice in the light of the impact of CT scan especially in the diagnostic procedures and treatments of brain tumor in children. Although the number of these procedures decreased up to 49% in plain skull X-ray, 54% in cerebral angiography, 70% in pneumoencephalography/ventriculography and 79% in nuclear brain scan after CT scan was installed in our results, it is extremely important to renew understanding of those characteristics in each special procedures. Cerebral angiography as well as pneumoencephalography may give the surgeon more precise ideas of the anatomical relationship between the lesion and other normal structures, especially in the posterior fossa tumor in which CT scan occassionally demonstrates only a gross finding. A case with false negative result and another case with a complicated anatomical structure in CT scan were presented. The significance of cerebral angiography and other invasive studies in the diagnosis and follow up of brain tumor in CT scan were discussed.

  15. The Beatles, the Nobel Prize, and CT scanning of the chest.

    Science.gov (United States)

    Goodman, Lawrence R

    2010-01-01

    From its first test scan on a mouse, in 1967, to current medical practice, the CT scanner has become a core imaging tool in thoracic diagnosis. Initially financed by money from Beatles' record sales, the first patient scan was performed in 1971. Only 8 years later, a Nobel Prize in Physics and Medicine was awarded to Hounsfield and Cormack for their discovery. This article traces the history of CT scanner development and how each technical advance expanded chest diagnostic frontiers. Chest imaging now accounts for 30% of all CT scanning.

  16. Value of CT scan in the diagnosis of primary large bowel lymphoma

    Institute of Scientific and Technical Information of China (English)

    赵修义; 张雪林; 王劲; 郑卫权; 文戈

    2003-01-01

    Objective:To study the CT imaging of primary large bowel lymphoma and evaluate the value of CT scan.Methods:CT reports of 8 patients with proven primary large bowel lymphoma were retrospectively reviewed.Plain CT scans were done on all patients,enhanced CT scans simultaneously with 5 - 10 mm section thickness,and 5 - 10 mm table increments in 6 cases.Results:Primary involved sites were on the cecum(n = 3),the ascending colon(n = 2),and the rectum(n = 1).The tumor was found in multiple areas of the large bowel in 2 cases.CT appearance fell into 3 typical patterns in our study.The first was focal mass type in 2 cases,with one combined with intussusception and retroperitoneal adenopathy; the second was segmental annular involvement type in 3 cases,with one of them combined with mesenteric adenopathy; the last was diffuse involvement type in 2 cases.Multiple nodules were seen in the rectum in 1 case.Conclusion:CT was found to be accurate in detecting the primary sites and complications of lymphoma,and evaluating invasion of adjacent structures; Focal mass type,segmental annular involvement type and diffuse involvement type are the main patterns of CT features in the primary large bowel lymphoma; The features revealed by CT scan are suggestive of primary large bowel lymphoma in some cases.

  17. [Metal artefact on head and neck cone-beam CT images].

    Science.gov (United States)

    Kovacs, Miklós; Fejérdy, Pál; Dobó, Nagy Csaba

    2008-10-01

    There are only a few factors, where the properties of the CBCT is inferior compared to conventional CT. One of these properties is the low contrast resolution, which has an importance in the discrimination of different soft tissues. Another difference is the image quality degrading effect by metal objects. This latter factor has much higher importance in head and neck region CBCT application. The metal artifact is closely related to other types of artifacts, like beam-hardening and x-ray photon scattering artifacts. In some of the cases, metal artifacts can be avoided by the proper adjustment of the scanning parameters, but sometimes the problem overgrows the possibilities. The current pre- and post-processing algorithms used for the correction of different artifacts can improve the image quality, but these algorithms are not the ultimate solution to the problem. The introduction of iterative reconstruction algorithms into the CBCT market will effectively reduce the most CT artifacts, however, the spread of this algorithms are set back because of the insufficient computational power of today's PCs. Another advantage of the use of iterative algorithms is that the patient dose could be significantly reduced.

  18. MR tomography after head and brain trauma: Comparison with CT, EEG and neurological examination

    Energy Technology Data Exchange (ETDEWEB)

    Dewes, W.; Moskopp, D.; Kurthen, M.; Solymosi, L.; Harder, T.; Kersting, G.

    1989-03-01

    56 patients with head and brain trauma and in coma were studied prospectively by means of MRT, CT, EEG and neurological examination. All patients had initial CT and EEG admission. MRT showed that in our patients morphological return to normal was the exception. Patients with head and brain injuries should be examined by MRT during the course of their illness. The use of special sequences, such as gradient-echo sequences for the diagnosis of haemorrhagic contusions, is indicated. CT should be retained for evaluating bone injury and cerebral damage during the acute stage.

  19. The use of CT-scanning at the medicolegal external postmortem examination and at the forensic autopsy

    DEFF Research Database (Denmark)

    Leth, Peter Mygind

    2006-01-01

    Introduction: Can CT-scanning of deceased at the medico legal external examination improve the selection of cases to autopsy? Is CT-scanning a substitute or a supplement to the traditional forensic autopsy? Material: In 2006 60 deceased individuals from Southern Denmark (counties of Fyn and Sønde......Introduction: Can CT-scanning of deceased at the medico legal external examination improve the selection of cases to autopsy? Is CT-scanning a substitute or a supplement to the traditional forensic autopsy? Material: In 2006 60 deceased individuals from Southern Denmark (counties of Fyn...... and Sønderjylland) (15 females and 45 males) were CT-scanned before autopsy. Method: A double-blind prospective investigation of CT-scanning in autopsy cases. A multislice spiral CT-scanner (Siemens Somatom Spirit) was used. Data from the CT-scanning and the autopsy were registered in a computer database...

  20. An Effort to Develop an Algorithm to Target Abdominal CT Scans for Patients After Gastric Bypass.

    Science.gov (United States)

    Pernar, Luise I M; Lockridge, Ryan; McCormack, Colleen; Chen, Judy; Shikora, Scott A; Spector, David; Tavakkoli, Ali; Vernon, Ashley H; Robinson, Malcolm K

    2016-10-01

    Abdominal CT (abdCT) scans are frequently ordered for Roux-en-Y gastric bypass (RYGB) patients presenting to the emergency department (ED) with abdominal pain, but often do not reveal intra-abdominal pathology. We aimed to develop an algorithm for rational ordering of abdCTs. We retrospectively reviewed our institution's RYGB patients presenting acutely with abdominal pain, documenting clinical and laboratory data, and scan results. Associations of clinical parameters to abdCT results were examined for outcome predictors. Of 1643 RYGB patients who had surgery between 2005 and 2015, 355 underwent 387 abdCT scans. Based on abdCT, 48 (12 %) patients required surgery and 86 (22 %) another intervention. No clinical or laboratory parameter predicted imaging results. Imaging decisions for RYGB patients do not appear to be amenable to a simple algorithm, and patient work-up should be based on astute clinical judgment.

  1. CT muscle scanning in the evaluation of patients with spinal muscular atrophy (SMA)

    Energy Technology Data Exchange (ETDEWEB)

    Sambrook, P.; Rickards, D.; Cumming, W.J.K.

    1988-12-01

    One hundred with spinal muscular atrophy (SMA) were assessed by CT scanning using a standardised technique. The spectrum of CT abnormality occurring in SMA was observed and by overall analysis the patients were divided into 4 groups. While the CT appearances of these groups correlated well with clinical assessment of severity of disease, the disease process was usually much more widespread than clinical examination suggested. CT abnormality was first observed in the leg and gluteal muscles, progressing to the posterior spinal, thigh, shoulder girdle and sternomastoid muscles. Hypertrophy of sartorius and gracilis was observed in a significant number of patients. Fascial planes were preserved in involved muscles in over half of the patients, even in late-stage disease. Asymmetrical muscle involvement was seen with increasing frequency as the disease process increased in extent as evaluated by CT scanning. There was no discernible difference in the CT appearances in those patients who clinically had limb-girdle, facioscapulohumeral or scapuloperoneal distribution of weakness.

  2. A low density area along the ventricular catheter on CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Yasuo; Ishii, Ryoji; Watanabe, Akira; Hirano, Kazuhiro; Kamada, Masaki; Okamura, Hironari (Kawasaki Medical School, Kurashiki, Okayama (Japan))

    1990-12-01

    Ten patients with hydrocephalus due to various causes, such as subarachnoid or intraventricular hemorrhage, had low density area (LDA) along the ventricular catheter on CT scans. This is an analysis of the 10 patients, with a discussion of the etiology. Ventriculoperitoneal (VS) shunt was performed in 8 patients, and 3 underwent ventricular drainage. None of the patients had postoperative hemorrhage. According to CT findings, the patients were divided into three groups. The first group consisted of 3 patients whose CT scans showed progressive ventricular dilatation and a presence of LDA along the ventricular catheter. After surgical resolution of high intraventricular pressure, repeated CT scans showed a remarkably decreased ventricles and LDA. In this group, an increased intraventricular pressure may play an important role in the formation of LDA. In the second group consisting of 3 patients, there was no postoperative CT evidence of progressive ventricular dilatation, but LDA was present. Follow-up CT scans revealed a decreased lesion. A slightly increased intraventricular pressure may result in LDA. In the last group of 4 patients, CT scans showed a small, irregular, marginal LDA along the ventricular catheter, with no evidence of increased ventricle. On repeated CT scans after conservative treatment, the lesion persisted for several years after VP shunt. There was a good correlation between CT findings and patient age. Children seemed to have a large porencephalic cyst. In conclusion, LDA may be an accumulation of CSF within the unresisting white matter along the ventricular catheter due to increased intraventricular pressure. Various CT patterns seem to depend on the increased degree of intraventricular pressure and the compliance of the surrounding white matter. (N.K.).

  3. Value of PET/CT in the approach to head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Curioni, Otavio Alberto; Amar, Ali; Viana, Debora [Hospital Heliopolis, Sao Paulo, SP (Brazil). Service of Head and Neck Surgery and Otorhynolaryngology; Souza, Ricardo Pires de [Hospital Heliopolis, Sao Paulo, SP (Brazil). Service of Radiology; Rapoport, Abrao [Hospital Heliopolis, Sao Paulo, SP (Brazil); Dedivitis, Rogerio Aparecido [Universidade de Sao Paulo (HC-FMUSP), SP (Brazil). Hospital das Clinicas. Group of Larynx and Hypopharynx; Cernea, Claudio Roberto; Brandao, Lenine Garcia [Universidade de Sao Paulo (FMUSP), SP (Brazil). Fac. de Medicina. Dept. of Head and Neck Surgery

    2012-11-15

    Objective: To evaluate the role of PET/CT in the approach to patients with head and neck cancer. Materials and Methods: Retrospective study of medical records and PET/CT images of 63 patients with head and neck cancer. Results: Alterations were observed in 76% of the cases. Out of these cases, 7 (11%) were considered as false-positive, with SUV < 5.0. PET/CT demonstrated negative results in 15 cases (24%). Among the 14 cases where the method was utilized for staging, 3 (22%) had their stages changed. Conclusion: PET/CT has shown to be of potential value in the routine evaluation of patients with head and neck cancer, but further studies of a higher number of cases are required to define a protocol for utilization of the method. (author)

  4. Coronal CT scan of paranasal sinuses; Long survey after Caldwell-Luc operation

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Atsuko (Tokyo Metropolitan Komagome Hospital (Japan)); Ikeda, Motohisa; Watanabe, Isamu; Komatsuzaki, Atsushi

    1994-03-01

    The clinical features were correlated with the coronal CT scan appearance of the paranasal sinuses of 49 patients who had received the Caldwell-Luc operation 16 to 58 years ago. The clinical diagnosis at the time of the CT scan was postoperative maxillary cyst in 22 patients, chronic sinusitis in 21 patients, trigeminal neuralgia in 3 patients, radicular cyst, postoperative ethmoid cyst and inverted papilloma in one patient each. The CT scans of the 91 operated maxillary sinuses showed obliterated cavity in 21 cases, small cavity in 46 cases, and cystic formation in 24 cases. The authors speculated that some maxillary sinuses which appeared in CT scans as small cavities might cause the clinical symptoms of postoperative maxillary cyst in the future. (author).

  5. Definitive role of CT scanning of the pancreas. The second year's experience.

    Science.gov (United States)

    Haaga, J R; Alfidi, R J; Havrilla, T R; Tubbs, R; Gonzalez, L; Meaney, T F; Corsi, M A

    1977-09-01

    In a group of 188 patients, 192 computed tomographic (CT) scans of the pancreas were done, and the diagnostic accuracy of CT determined relative to other modalities. CT was the most effective method of detecting neoplastic and inflammatory diseases. The full extent of the disease process, including involvement of the retroperitoneum and metastasis to the liver, was visualized with one examination. Calcification and cystic collections associated with pancreatitis were also clearly seen.

  6. Micro computed tomography (CT) scanned anatomical gateway to insect pest bioinformatics

    Science.gov (United States)

    An international collaboration to establish an interactive Digital Video Library for a Systems Biology Approach to study the Asian citrus Psyllid and psyllid genomics/proteomics interactions is demonstrated. Advances in micro-CT, digital computed tomography (CT) scan uses X-rays to make detailed pic...

  7. The presence and progression of emphysema in COPD as determined by CT scanning and biomarker expression

    DEFF Research Database (Denmark)

    Coxson, Harvey O; Dirksen, Asger; Edwards, Lisa D

    2013-01-01

    Emphysema is a key contributor to airflow limitation in chronic obstructive pulmonary disease (COPD) and can be quantified using CT scanning. We investigated the change in CT lung density in a longitudinal, international cohort of patients with COPD. We also explored the potential relation betwee...

  8. Patient-centered clinical impact of incidentally detected abnormalities on chest CT scans

    Directory of Open Access Journals (Sweden)

    Sherine G. Moftah

    2014-09-01

    Conclusion: The clinically significant different incidental abnormalities on chest CT scans represented 10.4% of all incidental findings, 3.3% were due to malignancies. The clinical impact of incidental abnormalities on chest CT may be of utmost importance on patient care.

  9. Evaluation of the use of automatic exposure control and automatic tube potential selection in low-dose cerebrospinal fluid shunt head CT

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Adam N.; Bagade, Swapnil; Chatterjee, Arindam; Hicks, Brandon; McKinstry, Robert C. [Barnes Jewish Hospital, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Washington University School of Medicine, St. Louis, MO (United States); Vyhmeister, Ross [Washington University School of Medicine, St. Louis, MO (United States); Ramirez-Giraldo, Juan Carlos [Siemens Healthcare, Malvern, PA (United States)

    2015-03-17

    Cerebrospinal fluid shunts are primarily used for the treatment of hydrocephalus. Shunt complications may necessitate multiple non-contrast head CT scans resulting in potentially high levels of radiation dose starting at an early age. A new head CT protocol using automatic exposure control and automated tube potential selection has been implemented at our institution to reduce radiation exposure. The purpose of this study was to evaluate the reduction in radiation dose achieved by this protocol compared with a protocol with fixed parameters. A retrospective sample of 60 non-contrast head CT scans assessing for cerebrospinal fluid shunt malfunction was identified, 30 of which were performed with each protocol. The radiation doses of the two protocols were compared using the volume CT dose index and dose length product. The diagnostic acceptability and quality of each scan were evaluated by three independent readers. The new protocol lowered the average volume CT dose index from 15.2 to 9.2 mGy representing a 39 % reduction (P < 0.01; 95 % CI 35-44 %) and lowered the dose length product from 259.5 to 151.2 mGy/cm representing a 42 % reduction (P < 0.01; 95 % CI 34-50 %). The new protocol produced diagnostically acceptable scans with comparable image quality to the fixed parameter protocol. A pediatric shunt non-contrast head CT protocol using automatic exposure control and automated tube potential selection reduced patient radiation dose compared with a fixed parameter protocol while producing diagnostic images of comparable quality. (orig.)

  10. Optimal arrangements of scanning heads for self-calibration of angle encoders

    Science.gov (United States)

    Jiao, Yang; Dong, Zeguang; Ding, Ye; Liu, Pinkuan

    2017-10-01

    The calibration of the angle encoder is necessary to improve the accuracy of angle measurement in precision rotating devices. Due to the characteristics of in situ calibration of encoders, self-calibration methods depending on special arrangements of multiple scanning heads have been widely used. Conventional works usually arrange the scanning heads in a regularly distributed way, generally involving too many scanning heads, especially when more high order Fourier components of the encoder error are calibrated. This paper presents an optimization-based arrangement method for self-calibration of angle encoders. Fourier approaches are used to determine the error of encoder from the angle differences measured between scanning heads. The relations between detectable Fourier components of the error and angular intervals of the heads are obtained from the properties of transfer functions. The optimal arrangements for two and three scanning heads, including the adjustment tolerances of the heads with the range of tested Fourier orders, are presented. The results of simulations and experiments demonstrate that the proposed optimal schemes can realize the same performance of calibration but with fewer scanning heads, compared to the conventional methods.

  11. Increase in dicentric chromosome formation after a single CT scan in adults.

    Science.gov (United States)

    Abe, Yu; Miura, Tomisato; Yoshida, Mitsuaki A; Ujiie, Risa; Kurosu, Yumiko; Kato, Nagisa; Katafuchi, Atsushi; Tsuyama, Naohiro; Ohba, Takashi; Inamasu, Tomoko; Shishido, Fumio; Noji, Hideyoshi; Ogawa, Kazuei; Yokouchi, Hiroshi; Kanazawa, Kenya; Ishida, Takashi; Muto, Satoshi; Ohsugi, Jun; Suzuki, Hiroyuki; Ishikawa, Tetsuo; Kamiya, Kenji; Sakai, Akira

    2015-09-09

    Excess risk of leukemia and brain tumors after CT scans in children has been reported. We performed dicentric chromosome assay (DCAs) before and after CT scan to assess effects of low-dose ionizing radiation on chromosomes. Peripheral blood (PB) lymphocytes were collected from 10 patients before and after a CT scan. DCA was performed by analyzing either 1,000 or 2,000 metaphases using both Giemsa staining and centromere-fluorescence in situ hybridization (Centromere-FISH). The increment of DIC formation was compared with effective radiation dose calculated using the computational dosimetry system, WAZA-ARI and dose length product (DLP) in a CT scan. Dicentric chromosome (DIC) formation increased significantly after a single CT scan, and increased DIC formation was found in all patients. A good correlation between the increment of DIC formation determined by analysis of 2,000 metaphases using Giemsa staining and those by 2,000 metaphases using Centromere-FISH was observed. However, no correlation was observed between the increment of DIC formation and the effective radiation dose. Therefore, these results suggest that chromosome cleavage may be induced by one CT scan, and we recommend 2,000 or more metaphases be analyzed in Giemsa staining or Centromere-FISH for DCAs in cases of low-dose radiation exposure.

  12. Advantage of CT scan in muscular pathology. Personal cases and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Laroche, M.; Rousseau, H.; Mazieres, B.; Bonafe, A.; Joffre, F.; Arlet, J.

    1989-05-01

    The advantage of CT scans in muscular pathology is studied. The scan, in addition to the diagnosis of tumors and muscular abscesses, permits to differentiate primary myopathies from neurogenic atrophies: in the course of myopathies, the muscle volume is preserved and they appear as a hypodensity; in neurogenic atrophies, the muscle volume is reduced with preserved density. The CT scan permits to determine the extension of these lesions. In the course of polymyositis, certain forms of rheumatid arthritis, the scan discloses a trabecular and 'worm-eaten' aspect of the muscles. This is also observed after long-term steroid therapy and other endocrine diseases (hyperthyroidism, osteomalacia) indicating an infra-clinical myopathy. In vertebral osteoporosis with fractures and patients with chronic lumbalgia, very ofter, an atrophy of the spinal muscle is observed. Finally, in the course of acquired kyphosis of the adult patient (camptocormia), the CT scan suggest an isolated myopathy, with late manifestations, of the paravertebral muscles.

  13. 3D Reconstruction in Spiral Multislice CT Scans

    Directory of Open Access Journals (Sweden)

    M. Ghafouri

    2005-08-01

    Full Text Available Introduction & Background: The rapid development of spiral (helical computed tomography (CT has resulted in exciting new applications for CT. One of these applications, three-dimensional (3D CT with volume ren-dering, is now a major area of clinical and academic interest. One of the greatest advantages of spiral CT with 3D volume rendering is that it provides all the necessary information in a single radiologic study (and there-fore at the lowest possible price in cases that previously required two or more studies. Three-dimensional vol-ume rendering generates clinically accurate and immediately available images from the full CT data set with-out extensive editing. It allows the radiologist and clinician to address specific questions concerning patient care by interactively exploring different aspects of the data set. Three-dimensional images integrate a series of axial CT sections into a form that is often easier to interpret than the sections themselves and can be made to appear similar to other more familiar images such as catheter angiograms. The data are organized into a 3D matrix of volume elements (voxels. The screen of the computer monitor is a 2D-surface composed of discrete picture elements (pixels. Presenting what is stored in memory (ie, floating within the monitor on a 2D-screen is a challenge, but it is the very problem that 3D reconstruc-tion software has creatively solved. Voxel selection is usually accomplished by projecting lines (rays through the data set that correspond to the pixel matrix of the desired 2D image. Differences in the images produced with various 3D rendering techniques are the result of variations in how voxels are selected and weighted. In this article, I compare 3D volume rendering of spiral CT data with other rendering techniques (shaded surface display, maximum intensity projection and present a brief history of 3D volume rendering and discuss the im-plementation of this promising technology in terms of

  14. Dual energy CT with one full scan and a second sparse-view scan using structure preserving iterative reconstruction (SPIR)

    Science.gov (United States)

    Wang, Tonghe; Zhu, Lei

    2016-09-01

    Conventional dual-energy CT (DECT) reconstruction requires two full-size projection datasets with two different energy spectra. In this study, we propose an iterative algorithm to enable a new data acquisition scheme which requires one full scan and a second sparse-view scan for potential reduction in imaging dose and engineering cost of DECT. A bilateral filter is calculated as a similarity matrix from the first full-scan CT image to quantify the similarity between any two pixels, which is assumed unchanged on a second CT image since DECT scans are performed on the same object. The second CT image from reduced projections is reconstructed by an iterative algorithm which updates the image by minimizing the total variation of the difference between the image and its filtered image by the similarity matrix under data fidelity constraint. As the redundant structural information of the two CT images is contained in the similarity matrix for CT reconstruction, we refer to the algorithm as structure preserving iterative reconstruction (SPIR). The proposed method is evaluated on both digital and physical phantoms, and is compared with the filtered-backprojection (FBP) method, the conventional total-variation-regularization-based algorithm (TVR) and prior-image-constrained-compressed-sensing (PICCS). SPIR with a second 10-view scan reduces the image noise STD by a factor of one order of magnitude with same spatial resolution as full-view FBP image. SPIR substantially improves over TVR on the reconstruction accuracy of a 10-view scan by decreasing the reconstruction error from 6.18% to 1.33%, and outperforms TVR at 50 and 20-view scans on spatial resolution with a higher frequency at the modulation transfer function value of 10% by an average factor of 4. Compared with the 20-view scan PICCS result, the SPIR image has 7 times lower noise STD with similar spatial resolution. The electron density map obtained from the SPIR-based DECT images with a second 10-view scan has an

  15. Accuracy of cancellous bone volume fraction measured by micro-CT scanning

    DEFF Research Database (Denmark)

    Ding, Ming; Odgaard, A; Hvid, I

    1999-01-01

    Volume fraction, the single most important parameter in describing trabecular microstructure, can easily be calculated from three-dimensional reconstructions of micro-CT images. This study sought to quantify the accuracy of this measurement. One hundred and sixty human cancellous bone specimens...... which covered a large range of volume fraction (9.8-39.8%) were produced. The specimens were micro-CT scanned, and the volume fraction based on Archimedes' principle was determined as a reference. After scanning, all micro-CT data were segmented using individual thresholds determined by the scanner...

  16. Is the Canadian CT head rule for minor head injury applicable for patients in Germany?; Laesst sich die Canadian CT Head Rule fuer das leichte Schaedel-Hirn-Trauma auf Deutschland uebertragen?

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, P.M.; Walter, M.A.; Kloska, S.P.; Heindel, W. [Inst. fuer Klinische Radiologie, Universitaetsklinikum Muenster (Germany); Rieger, B.; Wassmann, H. [Klinik und Poliklinik fuer Neurochirurgie, Universitaetsklinikum Muenster (Germany); Fischer, R.J. [Inst. fuer Medizinische Informatik und Biomathematik, Universitaetsklinikum Muenster (Germany)

    2005-06-01

    Purpose: to evaluate the applicability of the Canadian CT head rule (CCHR) on head trauma patients in a German university hospital. Methods: 122 patients (m = 74; f = 48; 40 {+-} 19 years) were examined with cranial CT due to minor head trauma. The need for cranial CT according to the CCHR was evaluated retrospectively. Results: with a sensitivity of 98.9% and a specificity of 46.6% all patients with the need for neurosurgical intervention were detected by applying the major criteria of the CCHR. Also, every patient with severe brain injury was detected by the extended criteria with a sensitivity of 99.6% and a specificity of 34.1%. This would have led to a reduction in the rate of cranial CT examinations by 45.1% for the major and 22.1% for the extended criteria. No patient with severe brain injury would have been missed by application of the criteria. Conclusion: the Canadian CT head rule for patients with minor head trauma is applicable with a very high sensitivity and the potential of significantly reducing the rate of cranial CT examinations in these patients. (orig.)

  17. Adherence to follow-up CT scans in patients with small pulmonary nodules, a retrospective study

    DEFF Research Database (Denmark)

    Johansson, Sofie Lock; Gerner Hansen, Niels-Christian

    2010-01-01

    Adherence to follow-up CT scans in patients with small pulmonary nodules, a retrospective study The Danish National guidelines have since 2008 suggested serial follow-up CT scans at 3, 6, 12, and 24 months for nodules between 5 and 10 mm and at 12 and 24 months for nodules less than 5 mm in accor...... is that management of the follow-up of small nodules did improve in 2008-2009, but adherence to the guidelines was still limited. We will now implement a prospective program for monitoring the adherence to the follow-up CTs.......Adherence to follow-up CT scans in patients with small pulmonary nodules, a retrospective study The Danish National guidelines have since 2008 suggested serial follow-up CT scans at 3, 6, 12, and 24 months for nodules between 5 and 10 mm and at 12 and 24 months for nodules less than 5 mm...... in the four year period 2006-2009. In 72 cases, 19 in 2006-2007 and 51 in 2008-2009, one or more small nodules, with diameter ≤ 10 mm, were detected on CT in patients with no known recent malignant disease. For these patients follow-up was suggested, either with CT or PET-CT. One of the 70 patients from 2008...

  18. Potential cancer risk associated to CT scan. State of the art of epidemiological studies

    Energy Technology Data Exchange (ETDEWEB)

    Bernier, Marie-Odile; Baysson, Neige Joumy Helene; Jacob, Sophie; Laurier, Dominique [Institute for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses (France). Lab. of Epidemiology

    2013-07-01

    Introduction: The increasing use of computed tomography (CT) scans in paediatric population raises the question of a possible health impact of ionizing radiation exposure associated with CT scans. Material and methods: Two large cohort studies have been recently published that assessed the risk of cancer related to CT examinations of children and young adults. Methodology and results of these studies are presented. Results: The UK cohort included over 176,000 young people, who underwent one or more CT scans between 1985 and 2002. The Australian study compared the risk of cancer and leukaemia in a population of 680,000 young people exposed to CT scans between 1985 and 2005 to non-exposed similar age people. Both studies showed a significant dose-response relation between exposure to CT and leukaemia or brain tumour risks. These results are consistent with predictions from A-bomb survivors' data. However, uncertainties in dosimetric estimation and potential bias linked to underlying medical conditions should be considered. Conclusion and perspectives: Further studies with more accurate dosimetry and assessment of potential bias and uncertainties are needed. Ongoing national studies and the European collaborative EPI-CT study will help to better understand the relation between low level radiation exposure and cancer and to support recommendations for patients'' radiation protection. (orig.)

  19. Evaluation of Helical CT Scanning in Judging the Invasion and Metastasis of Gastric Carcinoma

    Institute of Scientific and Technical Information of China (English)

    GAOJianbo; KONGXiangquan; GUOHua; LIShuxin; YANGXuehua; LIYintai; ZHANGZhixu

    2004-01-01

    To determine the accuracy of triphase enhanced helical CT in judging the invasion and metastasis of gastric carcinoma, and to discuss the relation between imaging signs and pathological findings. Methods: Triphase enhanced helical CT scanning was performed in 46 patients with gastric carcinoma. Imaging findings were compared with postoperative pathologic results. Results: (1) The accuracy of helical CT for diagnosing involvement of tunica serosa, lymph node metastasis and distant metastasis was 84.8%, 87.0% and 100~ respectively. (2) CT signs of serosal involvement, lymph node metastasis and distant metastasis were in good accordance with pathological findings (P<0.05). Conclusion: Triphase enhanced helical CT scans can comprehensively and precisely reflect the pathologic characteristics of gastric carcinoma, thus it is a reliable technique for the diagnosis of this disease.

  20. Body surface area determined by whole-body CT scanning: need for new formulae?

    DEFF Research Database (Denmark)

    Villa, Chiara; Primeau, Charlotte; Hesse, Ulrik

    2017-01-01

    Calculation of the estimated body surface area (BSA) by body height and weight has been a challenge in the past centuries due to lack of a well-documented gold standard. More recently, available techniques such as 3D laser surface scanning and CT scanning may be expected to quantify the BSA...... Mimics software, and BSA values were automatically extracted from the program. They were compared with nine predictive equations from the literature. Remarkably, close correlations (r > 0·90) were found between BSA values from CT scans and those from the predictive formulae. A mean BSA of the 54 cadavers...

  1. 'Out of hours' adult CT head interpretation by senior emergency department staff following an intensive teaching session: a prospective blinded pilot study of 405 patients.

    Science.gov (United States)

    Jamal, Karim; Mandel, Laura; Jamal, Leila; Gilani, Shamim

    2014-06-01

    Cranial CT is the gold standard for the investigation of intracranial emergencies. The aim of this pilot study was to audit whether senior emergency physicians were able to report CT head scans accurately and reliably having attended structured teaching. Senior emergency physicians attended a 3 h teaching session. Following this, they independently reported adult CT head scans between 22:00 and 08:00 using a pro forma. CT head examinations performed in this 'out of hours' period were formally reported by a consultant radiologist on the following morning. Data were collected in a blinded fashion over an 8-month period. 405 adult CT head examinations were performed. 360 pro formas were available for analysis, and the rest were excluded either because a consultant radiologist had been rung to discuss the results (five patients) or because the pro forma was not completed (40 patients). Concordance between consultant radiologists and emergency physicians was found in 339 (94%) of the cases (κ coefficient 0.78). None of the discordant cases was managed inappropriately or had an adverse clinical outcome. All cases of extradural, subdural and subarachnoid haemorrhage were detected by emergency physicians. In conclusion, we feel that this model can be employed as a safe and long-term alternative provided that the radiology department are committed to providing ongoing teaching and that a database is maintained to highlight problem areas. Emergency physicians need to remember that the clinical status of the patient must never be ignored, irrespective of their CT head findings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  2. Gambaran CT Scan Toraks Sesuai dengan Jenis Sitologi/Histologi pada Pasien Kanker Paru yang Merokok

    Directory of Open Access Journals (Sweden)

    Rosa Tatun

    2016-03-01

    Full Text Available Kanker paru merupakan  penyebab kematian paling banyak akibat keganasan. Kanker paru memberikan gambaran CT scan yang berbeda sesuai dengan jenis sitologi/histologinya. Pemeriksaan CT scan  toraksdengan teknik high resolution computed tomography (HRCT dapat memperlihatkan kelainan kanker parusecara rinci. Penelitian dilakukan di Instalasi Radiologi RSU Persahabatan, Jakarta bekerja sama denganDepartemen Pulmonologi dan Respirasi RSU Persahabatan terhadap 100 sampel yang diperoleh pada bulanNovember 2014 hingga Maret 2015. Berdasarkan jenis sitologi/histologi kanker paru (adenokarsinoma dankarsinoma sel skuamosa/KSS tidak ditemukan  variabel yang bermakna secara statistik  (bentuk, letak, tepispikulasi, tepi lobulasi, nodul satelit. Variabel yang paling banyak ditemukan pada adenokarsinoma maupunKSS adalah bentuk massa, lokasi di sentral dan paru sebelah kanan. Gambaran kanker paru adenokarsinomadan KSS pada pasien merokok paling banyak berupa massa, lokasi di sentral dan lobus kanan paru. Kata kunci: kanker paru, merokok, CT scan toraks   Lung Cancer CT Scan Findings in Smoker Patients Basedon Cytology/Histology Abstract Lung cancer is the leading cause of most deaths due to malignancy. Lung cancer CT scan provides an overview according to the type of cytology / histology. Thorax CT scan with high resolution technique (HRCT may revealdetail lung cancer abnormalities. This study was conducted between Department of Radiology and Departmentof Pulmonology Respiratory, Persahabatan Hospital Jakarta based on 100 samples, November 2014 until March2015. Based on cytological/histological type (adenocarcinoma and squamous cell carcinoma/KSS, it was not found significant meaningfull variables (shape, location, spiculate edge, lobulate edge, satellite nodules. Most commonly variables found in adenocarcinomas and KSS were mass forming, central location, right lung location.Most of adenocarcinoma and SCC in smoked patients were mass forming, central

  3. Three-Dimensions Segmentation of Pulmonary Vascular Trees for Low Dose CT Scans

    Science.gov (United States)

    Lai, Jun; Huang, Ying; Wang, Ying; Wang, Jun

    2016-12-01

    Due to the low contrast and the partial volume effects, providing an accurate and in vivo analysis for pulmonary vascular trees from low dose CT scans is a challenging task. This paper proposes an automatic integration segmentation approach for the vascular trees in low dose CT scans. It consists of the following steps: firstly, lung volumes are acquired by the knowledge based method from the CT scans, and then the data are smoothed by the 3D Gaussian filter; secondly, two or three seeds are gotten by the adaptive 2D segmentation and the maximum area selecting from different position scans; thirdly, each seed as the start voxel is inputted for a quick multi-seeds 3D region growing to get vascular trees; finally, the trees are refined by the smooth filter. Through skeleton analyzing for the vascular trees, the results show that the proposed method can provide much better and lower level vascular branches.

  4. CT scan findings and EEG in systemic lupus erythematodes patients with neuro-psychiatric disorders

    Energy Technology Data Exchange (ETDEWEB)

    Kan, Rumiko; Hagiwara, Mariko; Katayose, Keiko; Yashima, Yuko; Kumashiro, Hisashi

    1988-06-01

    In 14 patients with systemic lupus erythematodes presenting with neuro-psychiatric disorders, CT scans were compared with encephalographic (EEG) findings. CT findings were markedly abnormal in 6, slight with a sulcal enlargement in 3, and normal in 5. In the group of markedly abnormal CT findings, focal abnormal low density areas were detected in 2, severe generalized cerebral atrophy in one, and severe atrophy of the right hemisphere in one. EEG findings included focal paroxysmal abnormality of high voltage slow burst at the left frontal dominance and positive spike on the right hemisphere. Epileptic seizure and depressed sensorium seemed to be related to CT abnormality. In 3 patients with epileptic seizures, their symptoms were closely related to CT abnormality. Parkinsonisms and depressed sensorium were also related to CT abnormality. (Namekawa, K).

  5. A multicenter, randomized controlled trial of immediate total-body CT scanning in trauma patients (REACT-2).

    NARCIS (Netherlands)

    Sierink, J.C.; Saltzherr, T.P.; Beenen, L.F.; Luitse, J.S.; Hollmann, M.W.; Reitsma, J.B.; Edwards, M.J.R.; Hohmann, J.; Beuker, B.J.; Patka, P.; Suliburk, J.W.; Dijkgraaf, M.G.; Goslings, J.C.

    2012-01-01

    BACKGROUND: Computed tomography (CT) scanning has become essential in the early diagnostic phase of trauma care because of its high diagnostic accuracy. The introduction of multi-slice CT scanners and infrastructural improvements made total-body CT scanning technically feasible and its usage is curr

  6. A multicenter, randomized controlled trial of immediate total-body CT scanning in trauma patients (REACT-2)

    NARCIS (Netherlands)

    J.C. Sierink (Joanne); T.P. Saltzherr (Teun); L.F.M. Beenen (Ludo); J.S.K. Luitse; M.W. Hollmann (Markus); J.B. Reitsma (Johannes); M.J.R. Edwards (Michael); J. Hohmann (Joachim); B.J.A. Beuker (Benn); P. Patka (Peter); J.W. Suliburk (James); M.G.W. Dijkgraaf (Marcel); J.C. Goslings (Carel)

    2012-01-01

    textabstractBackground: Computed tomography (CT) scanning has become essential in the early diagnostic phase of trauma care because of its high diagnostic accuracy. The introduction of multi-slice CT scanners and infrastructural improvements made total-body CT scanning technically feasible and its u

  7. Measurement of radiation dose to ovaries from CT of the head and trunk

    Energy Technology Data Exchange (ETDEWEB)

    Al-Habdhan, M.A.M.; Kinsara, A.R. [King Abdul Aziz Univ., Nuclear Engineering Dept., Jeddah (Saudi Arabia)

    2001-07-01

    With the rise in concern about doses received by patients over recent years, there has been a growing requirement for information on typical doses and the range of dose received during Computerized Tomography (CT). This study was performed for the assessment of radiation dose to the ovaries from various CT protocols for head and trunk imaging. Thermo luminescent dosimeters (TLD) were used for the dosimetry measurement in an anthropomorphic Rando Alderson phantom. The wanted (obligatory) and unwanted (non-useful) radiation doses delivered to the ovaries during CT examinations of head, facial bone, orbits, abdomen, chest, pelvis, neck, nasopharynx, cervical spine, lumber spine and sacroiliac joint were assessed. The results are compared with the corresponding values published in the literature. A comparison of the received dose from CT examinations and general radiography examinations by the ovaries was made. It is found that relatively high doses of unwanted radiation are delivered with computerized tomography. (author)

  8. Kernohan’s Notch: A Forgotten Cause of Hemiplegia—CT Scans Are Useful in This Diagnosis

    Directory of Open Access Journals (Sweden)

    Ragesh Panikkath

    2013-01-01

    Full Text Available Hemiparesis ipsilateral to a cerebral lesion can be a false localizing sign. This is due to midline shift of the midbrain resulting in compression of the contralateral pyramidal fibers on the tough dural reflection tentorium cerebelli. This may result in partial or complete damage to these fibers. Since these fibers are destined to cross in the medulla and innervate the opposite side of the body, this causes hemiparesis ipsilateral to the site of cerebral lesion. Computed tomography (CT scans have not been used to support the diagnosis of this entity until now. We report a 68-year-old woman with a subdural hematoma who developed ipsilateral hemiparesis without any other explanation (Kernohan’s notch. The CT of the head showed evidence of compression of the midbrain contralateral to the hematoma and was useful in the diagnosis. The purpose of this report is to increase the awareness of this presentation and to emphasize the utility of CT scans to support the diagnosis.

  9. Automated segmentation of acetabulum and femoral head from 3-D CT images.

    Science.gov (United States)

    Zoroofi, Reza A; Sato, Yoshinobu; Sasama, Toshihiko; Nishii, Takashi; Sugano, Nobuhiko; Yonenobu, Kazuo; Yoshikawa, Hideki; Ochi, Takahiro; Tamura, Shinichi

    2003-12-01

    This paper describes several new methods and software for automatic segmentation of the pelvis and the femur, based on clinically obtained multislice computed tomography (CT) data. The hip joint is composed of the acetabulum, cavity of the pelvic bone, and the femoral head. In vivo CT data sets of 60 actual patients were used in the study. The 120 (60 x 2) hip joints in the data sets were divided into four groups according to several key features for segmentation. Conventional techniques for classification of bony tissues were first employed to distinguish the pelvis and the femur from other CT tissue images in the hip joint. Automatic techniques were developed to extract the boundary between the acetabulum and the femoral head. An automatic method was built up to manage the segmentation task according to image intensity of bone tissues, size, center, shape of the femoral heads, and other characters. The processing scheme consisted of the following five steps: 1) preprocessing, including resampling 3-D CT data by a modified Sinc interpolation to create isotropic volume and to avoid Gibbs ringing, and smoothing the resulting images by a 3-D Gaussian filter; 2) detecting bone tissues from CT images by conventional techniques including histogram-based thresholding and binary morphological operations; 3) estimating initial boundary of the femoral head and the joint space between the acetabulum and the femoral head by a new approach utilizing the constraints of the greater trochanter and the shapes of the femoral head; 4) enhancing the joint space by a Hessian filter; and 5) refining the rough boundary obtained in step 3) by a moving disk technique and the filtered images obtained in step 4). The above method was implemented in a Microsoft Windows software package and the resulting software is freely available on the Internet. The feasibility of this method was tested on the data sets of 60 clinical cases (5000 CT images).

  10. Impact of low-dose CT scan in dual timepoint investigations: a phantom study

    DEFF Research Database (Denmark)

    Micheelsen, M A; Jensen, Mikael

    2011-01-01

    with a CT image and also use the CT for attenuation correction. In any practical hospital setting, 1 hour is too long to occupy the scanner bed and a second CT procedure thus becomes necessary. This study tries to validate to what extent the dose/quality of the second CT scan can be lowered, without...... compromising attenuation correction, lesion detection and quantification. Using a standard NEMA phantom with the GE Discovery PET/CT scanner, taken in and out between scan sessions, we have tried to find the minimal CT dose necessary for the second scan while still reaching tissue activity quantification...... within predetermined error limits. For a hot sphere to background activity concentration ratio of 1:5, the average uptake (normalised by the time corrected input activity concentration) in a sphere of 6 cm3 was found to be 0.90 ± 0.08 for the standard scan, yielding a dose of 5.5 mGy, and 0.90 ± 0...

  11. Trends in CT scan rates in children and pregnant women: teaching, private, public and nonprofit facilities

    Energy Technology Data Exchange (ETDEWEB)

    Hoshiko, Sumi; Smith, Daniel; Fan, Cathyn; Jones, Carrie R.; McNeel, Sandra V. [Environmental Health Investigations Branch, California Department of Public Health, Richmond, CA (United States); Cohen, Ronald A. [Children' s Hospital and Research Center Oakland, Department of Radiology, Oakland, CA (United States)

    2014-05-15

    Radiation exposure from medical sources now equals or exceeds that from natural background sources, largely attributable to a 20-fold increase in CT use since 1980. Increasing exposure to children and fetuses is of most concern due to their heightened susceptibility. More recently, CT use may be leveling or decreasing, but it is unclear whether this change is widespread or varies by type of institution. We sought to characterize trends in CT utilization in California hospitals and emergency departments among children and pregnant women, looking at different types of facilities, such as teaching, private, public and nonprofit institutions. We examined frequency of CT examinations by year from 229 facilities reporting CT usage in routinely collected California statewide data for 2005-2012. We modeled trends overall and by facility type. CT scans for pediatric and pregnant patient visits in the emergency department increased initially, then started to decline after 2008. Among hospital admissions, rates declined or leveled after 2005. In the emergency department, CT rates varied between types of facilities, with teaching hospitals reducing use sooner and more sharply than other types of facilities. CT utilization in California among children and pregnant women has begun to level or decline. Still, population exposure remains at historically high levels, warranting consideration of potential public health implications. Further examination of reasons for trends among hospital types, particularly how teaching hospitals have reduced rates of CT utilization, may help identify strategies for CT reduction without compromising patient care. (orig.)

  12. Practice of CT scanning;Pratique de la tomodensitometrie

    Energy Technology Data Exchange (ETDEWEB)

    Kerviler, E. de [Assistance Publique - Hopitaux de Paris, Saint Louis, 75 - Paris (France)

    2009-10-15

    The proliferation of CT examinations necessitates the use of indicators of standard dose and reference levels. The dose.length product calculated from the computed tomography dose index (C.T.D.I.) is available on every recent machine and must appeared in the radiological report. Several techniques easily accessible to the console as the dose modulation, allow to reduce the dose to the patient. The combined use of these techniques allows dose reductions of more than 50%. The most important dose reductions are got in the organs with a strong contrast (lungs, sinus of the face). (N.C.)

  13. Pancreas tumor model in rabbit imaged by perfusion CT scans

    Science.gov (United States)

    Gunn, Jason; Tichauer, Kenneth; Moodie, Karen; Kane, Susan; Hoopes, Jack; Stewart, Errol E.; Hadway, Jennifer; Lee, Ting-Yim; Pereira, Stephen P.; Pogue, Brian W.

    2013-03-01

    The goal of this work was to develop and validate a pancreas tumor animal model to investigate the relationship between photodynamic therapy (PDT) effectiveness and photosensitizer drug delivery. More specifically, this work lays the foundation for investigating the utility of dynamic contrast enhanced blood perfusion imaging to be used to inform subsequent PDT. A VX2 carcinoma rabbit cell line was grown in the tail of the pancreas of three New Zealand White rabbits and approximately 3-4 weeks after implantation the rabbits were imaged on a CT scanner using a contrast enhanced perfusion protocol, providing parametric maps of blood flow, blood volume, mean transit time, and vascular permeability surface area product.

  14. Single energy micro CT SkyScan 1173 for the characterization of urinary stone

    Science.gov (United States)

    Fitri, L. A.; Asyana, V.; Ridwan, T.; Anwary, F.; Soekersi, H.; Latief, F. D. E.; Haryanto, F.

    2016-08-01

    A urinary stone is a solid piece of material produced from crystallization of excreted substances in the urine. Knowledge of the composition of urinary stones is essential to determine the suitable treatment for the patient. The aim of this research was to characterize urinary stones using single energy micro CT SkyScan 1173. Six human urinary stones were scanned in vitro using 80 kV in micro CT SkyScan 1173. The produced projection, images, were reconstructed using NRecon (in-house software from SkyScan). The images of urinary stones were analyzed using CT Analyser (CT An) to obtain information of the internal structure and the Hounsfield Unit (HU) value to determine the information regarding the composition of the urinary stones, respectively. The average HU values from certain region of interests in the same slice were compared with spectral curves of known materials from National Institute of Standards and Technology (NIST). From the analysis, the composition of the six scanned stones were obtained. Two stones are composed of cystine, two are composed of struvite, two other stones are composed of struvite+cystine. In conclusion, the single energy micro CT with 80 kV can be used identifying cystine and struvite urinary stone.

  15. Clinical utility of 18 Fluorodeoxyglucose (FDG-PET/CT scans in patients with suspect ocular tuberculosis

    Directory of Open Access Journals (Sweden)

    Salil Mehta

    2013-01-01

    Full Text Available Systemic imaging of patients with suspect ocular tuberculosis include chest X-rays and computed tomography (CT scans. Reports have suggested a role for 18 fluorodeoxyglucose-positron emission tomography/CT (FDG-PET/CT scans. We report on the clinical utility of 18 FDG PET/CT in two patients. Case 1: A 38-year-old female patient presented with recurrent anterior uveitis. A 18 FDG-PET scan revealed metabolically active supraclavicular and chest lymph nodes. An aspiration cytology of the cervical lymph node revealed caseating granulomas suggestive of tuberculosis. Case 2: A 58-year-old female patient presented with recurrent anterior uveitis. A 18 FDG-PET scan revealed metabolically active lymph nodes in the neck. A biopsy of the cervical lymph node revealed epithelioid granulomas suggestive of tuberculosis. Both patients were started on standard antitubercular therapy with a subsequent marked reduction of activity. PET/CT scans may suggest the sites of safe high-yield biopsies.

  16. Optimization in the relation between image quality and patient dose in head CT

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Diaz, M.; Paz-Viera, J.E., E-mail: mperez@uclv.edu.cu [Center for Studies on Eletronics and Info. Tech., Universidad Central ' Marta Abreu' , Santa Clara (Cuba); Carvalho Filho, A.E. [Universidade Estadual de Santa Cruz, Ilheus, BA (Brazil). Departamento de Ciencias Exatas e Tecnologicas; Andrade, M.E.A.; Khoury, H.J. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear

    2013-08-15

    Thirty-two head CT scans were acquired employing an anthropomorphic phantom containing lesions in the posterior fossa, using 2 scanners: Siemens Sensation with 64 slices and Philips Brilliance with 6 slices. Parameters as tube current (mA), slice thickness (mm), collimation (mm), tube potential (kVp) and dynamic range were changed during studies, looking for the optimal acquisition/processing conditions which permit both good lesion detectability and the lowest dose. The CT air kerma index (mGy) was measured with a pencil ionization chamber. Image quality was analyzed by 5 radiologists using a 5 points-scale criteria (1=poor, 2=fair, 3=good, 4=very good, 5=excellent) and also using 5 figure of merit in the spatial and frequency domains: Contrast (C [%]), Contrast to Noise Ratio (CNR), Signal to Noise Ratio (SNR), Normalized Mean Square Error (NMSE) and Spectral Distance (SD). Objective and subjective results were correlated. We observed that doses could be reduced by up to 25% respect to the usual practice with both scanners, mainly reducing the mAs, without affecting lesion detection. As a result, we propose an optimized protocol for each scanner as follow: 250 mAs, 120 kVp and the collimation of 6 slices x 1.50 mm per rotation the same reconstructed slice thickness to detect the lesions in the posterior fossa with good image quality for the Philips Brilliance 6, while 150 mAs, 100 kVp, collimation of 30 x 1.2 mm and reconstructed slice thickness of 3.0 mm were needed with the Siemens Sensation 64. (author)

  17. COEXISTENCE OF OSTEOARTHRITIS AND OSTEOPOROSIS INFEMORAL HEAD: A SCANNING ELECTRONMICROSCOPIC STUDY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To ascertain the coexistence of osteoarthritis and osteoporosis in the femoral head . Methods During total hip replacement for osteoarthritis of hip joint in 12 female patients with an average age of 56 years, the femoral heads were procured. After processing the femoral head, specimens were studied under scanning electron microscope. Results Different degrees of osteoarthritic lesions (characterized by degeneration of articular cartilage and hyperplasia of subchondral bone tissues) could coexist with osteoporotic lesions (characterized by icicle-like trabeculae ) in the femoral head. The hyperplas tic bone tissues of osteoarthritis lay in the vicinity of icicle-like trabeculae. However, they did not come into contact, nor did they exert influence on each other. Coexistence of these two different lesions covered a broad territory extending from the deep surface of subchondral bone plate to the head-neck junction of femoral head. Conclusion The results suggest that os teoarthritis and osteoporosis do coexist in the femoral head.

  18. Feasibility of low-dose contrast medium high pitch CT angiography for the combined evaluation of coronary, head and neck arteries.

    Directory of Open Access Journals (Sweden)

    Zhiwei Wang

    Full Text Available PURPOSE: To evaluate the image quality and radiation dose of combined heart, head, and neck CT angiography (CTA using prospectively electrocardiography (ECG-triggered high-pitch spiral scan protocol, compared with single coronary CTA. MATERIALS AND METHODS: 151 consecutive patients were prospectively included and randomly divided into three groups. Group 1 (n = 47 underwent combined heart, neck, and head CTA using prospectively ECG-triggered high-pitch spiral (Flash scan protocol with a single-phase intravenous injection of iodinated contrast and saline flush; Group 2 (n = 51 underwent single coronary CTA with Flash scan protocol; and Group 3 (n = 53 underwent single coronary CTA with prospective sequence scan protocol. All patients were examined on a dual source CT (Definition FLASH. The image quality was determined for each CT study. RESULTS: Patients of scanning protocol Group 1, 2, and 3 showed no significant differences in age, sex, heart rates, and BMI. Evaluation of coronary artery image quality showed comparable results in the three scanning protocol groups on a per patient-based analysis. In group 1, image quality was found to be sufficient to be diagnostic in all arterial segments of carotid arteries. The mean dose-length product (DLP for group 1 was 256.3±24.5 mGy×cm and was significantly higher in comparison with group 2 (93.4±19.9 mGy×cm; p < 0.001. However, there was no significant difference of DLP between group 1 and group 3 (254.1±69.9 mGy×cm. CONCLUSIONS: The combined heart, neck, and head arteries scan using prospectively electrocardiography (ECG-triggered high-pitch spiral scan protocol in 1 single examination resulted in an excellent opacification of the aorta, the carotid arteries, and the coronary arteries and provided a good image quality with low radiation dose.

  19. It's not a cervical lymph node, it's a vein: CT and MR imaging findings in the veins of the head and neck.

    Science.gov (United States)

    Escott, Edward J; Branstetter, Barton F

    2006-01-01

    The anatomy and imaging appearances of the veins of the head and neck can vary considerably, and normal veins may mimic disease processes at computed tomography (CT) and magnetic resonance (MR) imaging. On unenhanced CT scans, aberrant veins may be difficult to differentiate from lymph nodes or other pathologic conditions. Even at contrast material-enhanced CT, differences in venous enhancement or the mixing of opacified with nonopacified blood can lead to confusion, particularly if the vein is focally dilated. Similarly, the size and signal intensity of head and neck veins may vary at MR imaging due to slow or turbulent flow or variable enhancement, resulting in misdiagnosis. A thorough understanding of the normal venous anatomy and common variants is necessary to properly differentiate an unopacified or focally dilated vein from lymphadenopathy or some other disease entity and can help the radiologist avoid the erroneous interpretation of findings.

  20. Nonconcordance between Clinical and Head CT Findings: The Specter of Overdiagnosis

    Directory of Open Access Journals (Sweden)

    Kelli N. O'Laughlin

    2013-01-01

    Full Text Available Background. It is unclear whether history and physical examination findings can predict abnormalities on head computed tomography (CT believed to indicate increased risk of lumbar-puncture- (LP- induced brain herniation. The objectives of this study were to (1 identify head CT findings felt to be associated with increased risk of brain herniation and (2 to assess the ability of history and physical examination to predict those findings. Methods. Using a modified Delphi survey technique, an expert panel defined CT abnormalities felt to predict increased risk of LP-induced brain herniation. Presence of such findings on CT was compared with history and physical examination (H&P variables in 47 patients. Results. No H&P variable predicted “high-risk” CT; combining H&P variables to improve sensitivity led to extremely low specificity and still failed to identify all patients with high-risk CT. Conclusions. “High-risk” CT is not uncommon in patients with clinical characteristics known to predict an absence of actual risk from LP, and thus it may not be clinically relevant. “Overdiagnosis” will be increasingly problematic as technological advances identify increasingly subtle deviations from “normal.”

  1. A novel reconstruction tool (syngo DynaCT Head Clear) in the post-processing of DynaCT images to reduce artefacts and improve image quality.

    Science.gov (United States)

    Lescher, Stephanie; Reh, Christina; Hoelter, Maya Christina; Czeppan, Katja; Porto, Luciana; Blasel, Stella; Berkefeld, Joachim; Wagner, Marlies

    2016-01-19

    Latest generations of flat detector (FD) neuroangiography systems are able to obtain CT-like images of the brain parenchyma. Owing to the geometry of the C-arm system, cone beam artifacts are common and reduce image quality, especially at the periphery of the field of view. An advanced reconstruction algorithm (syngo DynaCT Head Clear) tackles these artifacts by using a modified interpolation-based 3D correction algorithm to improve image quality. Eleven volumetric datasets from FD-CT scans were reconstructed with the standard algorithm as well as with the advanced algorithm. In a two-step data analysis process, two reviewers compared dedicated regions of the skull and brain in both reconstruction modes using a 5-point scale (1, much better; 5, much worse; advanced vs standard algorithm). Both reviewers were blinded to the reconstruction mode. In a second step, two additional observers independently evaluated image quality of the 3D data (non-comparative evaluation) in dedicated regions also using a 5-point scale (1, not diagnostically evaluable; 5, good quality, perfectly usable for diagnosis) for both reconstruction algorithms. Both in the comparative evaluation of dedicated brain regions and in the independent analysis of the FD-CT datasets the observers rated a better image quality if the advanced algorithm was used. The improvement in image quality was statistically significant at both the supraganglionic (p=0.018) and the infratentorial (p=0.002) levels. The advanced reconstruction algorithm reduces typical artifacts in FD-CT images and improves image quality at the periphery of the field of view. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  2. CT120A Acts as an Oncogene in Head and Neck Squamous Cell Carcinoma

    Science.gov (United States)

    Baltaci, Elif; Ekizoglu, Seda; Sari, Elif; Karaman, Emin; Ulutin, Turgut; Buyru, Nur

    2015-01-01

    Squamous cell carcinoma of the head and neck (HNSCC) is among the most frequent cancers worldwide. The etiology and pathogenesis of HNSCC are influenced by multiple genetic factors in addition to environmental and lifestyle-related factors. However, the mechanism underlying the HNSCC is still far from clear. The membrane associated gene CT120 was previously identified from chromosome 17p13.3 as a lung cancer-associated gene. Its function as an activator of the Erk and Akt signaling pathways in human lung cancer cell lines suggested that CT120 has an oncogenic function. However, there is no data in the literature on the role of CT120 in any other cancer type. Therefore, the aim of this study was to determine the expression rate and probable function of CT120 in HNSCC. Tumor tissues from 50 patients were analyzed by real-time quantitative RT-PCR to investigate the expression rate and by direct sequencing to differentiate the CT120A and CT120B variants. CT120 overexpression was observed in 58% of tumors compared to non-cancerous tissue samples and this up-regulation was directly associated with the upregulation of the CT120A variant and with the stage of the disease (p=0.001). Our results indicate that the CT120 gene may function in the development of HNSCC. PMID:26535067

  3. EFEKTIFITAS VARIASI NILAI WINDOW LEVEL TERHADAP KUALITAS HASIL CT SCAN THORAX LUNG WINDOW

    OpenAIRE

    dani, Rahma

    2014-01-01

    EFEKTIFITAS VARIASI NILAI WINDOW LEVEL TERHADAP KUALITAS HASIL CT SCAN THORAX LUNG WINDOW Rahmadani Jurusan Fisika, FMIPA, Universitas Hasanuddin, Makassar 90245, Indonesia Pembimbing Utama : Prof. Dr. H. Halmar Halide, M.Sc Pembimbing Pertama : Dahlang Tahir, M.Sc. Phd ABSTRAK Telah dilakukan penelitian untuk mengetahui efek variasi nilai window level terhadap kualitas hasil CT Scann thorax lung window dengan pengaturan window width 1000,1500, 2000 dengan varias...

  4. Detection of Dental Pathologies in Routine Paranasal CT Scans: A Retrospective Study.

    Science.gov (United States)

    Bulbul, Erdogan; Yanik, Bahar; Demirpolat, Gulen

    2017-07-01

    Multidetector Computed Tomography (MDCT) is a widespread method for evaluating paranasal sinuses and nasal cavity in daily practice. The maxillary teeth are in field of view in a paranasal sinus CT scan and it is possible to detect dental pathologies with CT. To determine the incidence of maxillary teeth pathologies in routine paranasal sinus CT scans. A retrospective study was conducted. Consecutive 395 paranasal sinus CT scans were evaluated. All CT images were obtained with a 64 detector-CT. Patients with previous facial trauma, operation, invasive tumors and repeated exams were excluded. Detected findings were classified as "tooth loss, dental restorations or procedures and dental pathologies (carious lesions, dental developmental anomalies, periapical lesions and periodontal diseases). The proportion of findings was reported as simple percentiles. Three hundred and eighty-four CT scans were included in the study. Dental restorations or procedures were determined in 129 (33.5%) patients. A total of 34 (8.8%) patients had normal teeth count and morphology. A total of 264 (64.3%) patients had at least one tooth loss. A total of 195 (51%) patients had at least one or more dental pathology. Number of dental carious lesions, dental developmental anomalies, periapical lesions and periodontal disease were 104 (27.0%), 78 (14.3%), 46 (11.9%), 44 (11.4%), respectively. Dental pathologies were encountered in more than half of the patients. Detecting dental pathologies may prevent tooth loss and improve oral health. The radiologist should keep in mind dental pathologies while evaluating paranasal sinus CT in daily practice.

  5. Efficacy of CT scanning in a group of 174 patients with orthopedic and musculoskeletal problems

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, H.J.; Hamlin, D.J.; Kiss, S.; Lovelock, J.

    1981-11-01

    One hundred and seventy-four patients with orthopedic and musculoskeletal problems received computed tomography (CT) scans between January 1979 and July 1980. There were 34 trauma patients, 35 patients with known or suspected primary tumors, 20 patients with metastases, 18 patients with suspected spinal stenosis, 25 patients with disc problems, five patients with infections, 13 children with congenital anomalies, and 24 patients with miscellaneous problems. The CT scans proved useful in all the pediatric cases, 97% of the trauma patients, and in the majority of patients with tumors. It appears that absolute indications for CT scanning in orthopedic patients include acute trauma to the spine, pelvis, hip, and shoulder girdles as well as in children with congenital spinal anomalies. Relative indications include determining the extent of the tumor and also aiding in the correct approach for biopsying a lesion.

  6. Serial CT scans of cerebral hypoxia due to prolonged status epilepticus

    Energy Technology Data Exchange (ETDEWEB)

    Saiwai, Shigeo; Matsumura, Yasumasa; Tamaoka, Koichi; Fukuda, Teruo; Miyamoto, Takeshi (Kobe Central Municipal Hospital, Kobe (Japan))

    1983-04-01

    Serial computed tomography (CT) scans of 5 infants with status epilepticus were reviewed. Four out of the 5 infants fortunately had CT scans before status epilepticus because of a convulsion. There was a diffuse and mild low density in the hemisphere, with small ventricles and tight sulci (brain swelling) at 1 to 2 days after ictus. Thereafter, a diffuse low density became apparent except for the cerebellum, the brain stem, the thalamus, and the basal ganglia. Two to 4 weeks after ictus, a localized, mottled low density was demonstrated on the cerebral mantle and atrophic changes became progressively clear. In 3 cases, no abnormal enhancement was elicited on contrast CT scans performed between 5 to 16 days after status epilepticus. We discussed the possible pathophysiological aspects of the brain damage due to ''prolonged status epilepticus.''

  7. Drusen of the optic nerve head in CT imaging; Druzy tarczy nerwu wzrokowego w obrazie tomografii komputerowej

    Energy Technology Data Exchange (ETDEWEB)

    Kabula, S.; Stefaniak, E.; Burzynska-Makuch, M.; Boron, Z. [Akademia Medyczna, Bydgoszcz (Poland)

    1994-12-31

    The optic nerve head drusen are non-cell formations, which are almost always calcified. They have a characteristic feature in CT examination, what can be helpful in differentiation from calcifications of the other origin, located in the posterior globe. Authors present cases of the optic nerve head drusen with typical feature in CT examination. (author). 4 refs, 1 fig.

  8. Relationship between lower third molar and mandibular canal; Preoperative evaluation using CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Itou, Masaki; Miyagishima, Toshio; Onizuka, Hiroyuki (Fujieda City Shida General Hospital, Shizuoka (Japan)); Takagi, Norio

    1994-01-01

    The mandibular canal is often closely related to the lower third molars. During the surgical removal of the third molar, the inferior alveolar nerve in the canal is sometimes damaged leading to impaired sensation in the lower lip. This is one of the most unpleasant postoperative complications. The buccolingual relationship between the lower third molar and the mandibular canal cannot be diagnosed by ortho-pantomography although preoperative evaluation must be carried out radiologically. In present study, the relationship was determined by using CT scan. Forty-seven lower third molars of 35 patients were evaluated preoperatively by CT scan. The mandibular canal of all cases overlapped with the third molar on ortho-pantomography. CT scan was taken in two ways. The first was the Tragion-Menton plane which was nearly parallel to the canal at the apex of the third molar. The second was the plane of the axis of the third molar. Axial CT scan was taken when the third molar erupted horizontally, and coronal CT scan was done when the molar erupted vertically. CT scan examination exactly revealed the position of the mandibular canal in relation to the root of the third molar. The canal was located buccally to the roots in 55 percent of cases, apicobuccally in 6 percent, apically in 23 percent, apicolingually in 6 percent, lingually in 2 percent, and between roots in 6 percent. The results of the present study were consistent with previous reports. In 12 cases, the inferior alveolar neurovascular bundle was visible during operation. It was visible in only 2 of 22 cases when the canal was located buccally. It was visible, on the other hand, in all cases in which the canal was located apicolingually, lingually, and between roots. It also tended to be visible when the canal overlapped more strongly with the third molar on preoperative ortho-pantomography. (author).

  9. Initial brain CT scan and shunting outcomes in children with hydrocephalus

    Directory of Open Access Journals (Sweden)

    Andi Anita Utami

    2013-04-01

    Full Text Available Background Hydrocephalus is one of the most common clinical conditions affecting the central nervous system, with a congenital hydrocephalus incidence of 3-4 per 1000 births. Incidence of acquired types of hydrocephalus is unknown. Brain computerised tomography (CT scan can be used to assess the size of ventricles and other structures. Shunting has long been performed to alleviate hydrocephalus. Shunting has dramatically changed the outlook of children with hydrocephalus, with many of them having normal life expectancies and attaining normal intelligence. Objective To determine the outcomes of shunting in children with hydrocephalus based on initial brain CT scan. Methods We performed a cross-sectional study in Dr. Kariadi Hospital. Initial brain CT scan data were collected from the medical records of children admitted to the Neurosurgery Ward for ventriculoperitoneal (VP shunt surgery from January 2009 to December 2010. We studied the brain CT scan findings before VP shunt surgery and the outcomes of the children after VP shunt surgery. Radiological findings were determined by a radiologist responsible at that time. Results This study consisted of 30 subjects, 19 boys and 11 girls. Initial brain CT scans to assess disease severity revealed the following conditions: lateral ventricle dilatation in 7 subjects, lateral and third ventricle dilatation in 16 subjects, and lateral, third and fourth ventricle dilatation in 7 subjects. After VP shunt surgery, 3 subjects in the lateral, third and fourth ventricle dilatation category died. They were grouped according to their condition. Group 1 consisted of subjects with only lateral ventricle dilatation and subjects with lateral and third ventricle dilatation (23 subjects, while group 2 consisted of subjects with lateral, third and fourth ventricle dilatation (7 subjects. More survivors were found in group 1 than those in group 2. Conclusion Less severe initial brain CT scan findings are associated with

  10. Body surface area determined by whole-body CT scanning: need for new formulae?

    Science.gov (United States)

    Villa, Chiara; Primeau, Charlotte; Hesse, Ulrik; Hougen, Hans Petter; Lynnerup, Niels; Hesse, Birger

    2017-03-01

    Calculation of the estimated body surface area (BSA) by body height and weight has been a challenge in the past centuries due to lack of a well-documented gold standard. More recently, available techniques such as 3D laser surface scanning and CT scanning may be expected to quantify the BSA in an easier and more accurate way. This study provides the first comparison between BSA obtained from post-mortem whole-body CT scans and BSA calculated by nine predictive formulae. The sample consisted of 54 male cadavers ranging from 20 to 87 years old. 3D reconstructions were generated from CT scans using Mimics software, and BSA values were automatically extracted from the program. They were compared with nine predictive equations from the literature. Remarkably, close correlations (r > 0·90) were found between BSA values from CT scans and those from the predictive formulae. A mean BSA of the 54 cadavers of 1·84-1·87 m(2) was calculated by all formulae except one, SD values varying between 0·171 and 0·223 m(2) . T-tests revealed significant differences between mean BSA values calculated with CT and three of the formulae. Regression analyses showed intercepts >(0;0) and slopes <1·0 using all predictive equations, with the CT scan determination as gold standard. It is concluded that DuBois and DuBois' equation can be safely used in normal-weight male subjects with high accuracy, but it seems likely that BSA is underestimated in underweight subjects and overestimated in overweight individuals. Creation of new formulae specific for overweight subjects and children may be needed.

  11. Advanced material separation technique based on dual energy CT scanning

    Science.gov (United States)

    Zamyatin, Alexander A.; Natarajan, Anusha; Zou, Yu

    2009-02-01

    We propose a method for material separation using dual energy data. Our method is suitable to separation of three or more materials. In this work we describe our method and show results of numerical simulation and with real dual-energy data of a head phantom. The proposed method of constructing the material separation map consists of the following steps: Data-domain dual energy decomposition - Vector plot - Density plot - Clustering - Color assignment. Density plots are introduced to allow automatic cluster separation. We use special image processing methods, including Gaussian decomposition, to improve the accuracy of material separation. We also propose using the HSL color model for better visualization and to bring a new dimension in material separation display. We study applications of bone removal and virtual contrast removal. Evaluation shows improved accuracy compared to standard methods.

  12. CT scan findings of fungal pneumonia; Diagnose der Pilzpneumonie in der Thorax-CT

    Energy Technology Data Exchange (ETDEWEB)

    Heckmann, M.; Uder, M.; Bautz, W.; Heinrich, M. [Erlangen-Nuernberg Univ., Erlangen (Germany). Inst. fuer Diagnostische Radiologie

    2008-07-01

    The importance of fungal infection of the lung in immunocompromised patients has increased substantially during the last decades. Numerically the most patients are those with neutropenia, e.g. patients with malignancies or solid organ and stem cell transplantation, chemotherapy, corticosteroid use and HIV infection. Although fungal infections can occur in immunocompetent patients, their frequency in this population is rare. The clinical symptoms such as fever accompanied with non-productive cough are unspecific. In some patients progression to hypoxemia and dyspnea may occur rapidly. In spite of improved antifungal therapy morbidity and mortality of these infections are still high. Therefore an early and non-invasive diagnosis is very important. That is why CT and even better High-Resolution-CT (HR-CT) is a very important modality in examining immunocompromised patients with a probability of fungal infection. CT is everywhere available and, as a non-invasive method, able to give the relevant diagnose efficiently. This paper should give an overview about the radiologic findings and possible differential diagnosis of diverse pulmonary fungal infections in CT. Pneumonias caused by Aspergillus, Cryptococcus, Candida, Histoplasma, Mucor and Geotrichum capitatum are illustrated. (orig.)

  13. A vast increase in the use of CT scans for investigating occult hip fractures

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Robert, E-mail: Robert.jordan@doctors.org.uk; Dickenson, Edward, E-mail: edwarddickenson@doctors.org.uk; Westacott, Daniel, E-mail: dan_westacott@hotmail.com; Baraza, Njalalle, E-mail: njaleb@Doctors.Org.Uk; Srinivasan, Kuntrapka, E-mail: bijusri@Yahoo.Co.Uk

    2013-08-15

    Background: Early diagnosis in neck of femur fractures has been shown to improve outcome. The National Institute for Clinical Excellence recommends if an occult hip fracture is suspected then an MRI should be performed and if not available within 24 h a CT should be considered. At our centre, emergency MRI is rarely available and so CT is commonly used. Objectives: Our study aims to analyse the trends in CT use over a five year period for the diagnosis of neck of femur fractures. Methods: Both the number of patients with a hip fracture and those undergoing a CT hip to diagnose an occult injury were identified across two district general hospitals between 2006–2007 and 2010–2011. The time from initial radiograph to CT and initial radiograph to operation were calculated. Results: In 2006–2007, of 547 hip fractures, 20 CT hips were performed and 6 reported as a fractured neck of femur (30%). In 2010–2011, of 499 hip fractures, 239 CT hips were performed and 65 fractures were recognised (27%). The mean time from radiograph until CT scan was 2.0 days in 2007 and 3.2 days in 2011, which was a statistically significant difference (p < 0.001). For those diagnosed using a CT scan the mean time from admission X-ray to surgery was 1.2 days in 2007 and 3.6 days in 2011. Conclusion: Clinicians are becoming increasingly reliant on CT for the diagnosis of hip fractures with our data suggesting further imaging is one factor that can delay time to diagnosis and theatre.

  14. A comparative study of the diagnostic accuracy on Waters view with CT scan in detecting midface fractures

    OpenAIRE

    Panjnoush M.; Shirani Gh.; Jozghanbari P.

    2006-01-01

    Background and Aim: In recent years, CT scan has become available as an alternative to conventional radiography. To date, the utility of Waters view in detecting midface fractures has been rarely evaluated. The aim of this study was to compare the diagnostic accuracy and reliability of Waters radiography with CT scan in detecting midface fractures. Materials and Methods: In this tests evaluation study, waters view and CT scan were performed for 42 patients with midface fracture admitted to ma...

  15. Utility of head CT in the evaluation of vertigo/dizziness in the emergency department.

    Science.gov (United States)

    Lawhn-Heath, Courtney; Buckle, Christopher; Christoforidis, Gregory; Straus, Christopher

    2013-01-01

    Acute dizziness (including vertigo) is a common reason to visit the emergency room, and imaging with head CT is often performed initially to exclude a central cause. In this study, consecutive patients presenting with dizziness and undergoing head CT were retrospectively reviewed to determine diagnostic yield. Four hundred forty-eight consecutive head CTs in a representative sample of dizzy emergency room (ER) patients, including patients with other neurological symptoms, were reviewed to identify an acute or subacute cause for acute dizziness along with the frequency and modalities used in follow-up imaging. The diagnostic yield for head CT ordered in the ER for acute dizziness is low (2.2 %; 1.6 % for emergent findings), but MRI changes the diagnosis up to 16 % of the time, acutely in 8 % of cases. Consistent with the American College of Radiology appropriateness criteria and the literature, this study suggests a low diagnostic yield for CT in the evaluation of acute dizziness but an important role for MRI in appropriately selected cases.

  16. Congenital Pyloric Atresia with Distal Duodenal Atresia- Role of CT Scan

    Directory of Open Access Journals (Sweden)

    Yogender Singh Kadian

    2014-07-01

    Full Text Available The mainstay of diagnosis of congenital pyloric atresia is by plain X-ray of the abdomen showing a large gas bubble with no gas distally. But very rarely it can be associated with distal duodenal atresia when the baby may present as lump abdomen. In such a situation apart from the X-ray, another radiological investigation is needed to delineate the exact nature of the lump. Since the role of ultrasonography is limited in intestinal pathologies and contrast studies are not informative in atresias, the CT scan is the ideal choice. We had managed a case of pyloric atresia with similar presentation with preoperative CT scan.

  17. Subperiosteal chondroma. Diagnostic value of CT scan imaging in two cases

    Energy Technology Data Exchange (ETDEWEB)

    Lerais, J.M.; Auquier, F.; Baudrillard, J.C.; Durot, J.F.; Laugareil, P.; Wallays, C.; Lefort, G.; Daoud, S.; Gaillard, D.

    1988-01-01

    Results of CT scan exploration are reported in two cases of subperiosteal chondroma, one in a 4 year old child affecting the anterior tibial tuberosity the other in a 9 year old child involving the upper end of humerus. Data from CT scan imaging were undoubtedly superior to those of conventional radiography and appear to be characteristic of this benign cartilaginous tumor, greatly facilitating correlation between clinical, radiological and pathologic findings. The scanner should allow certain situations to be dedramatized and the surgical attitude adapted when the functional prognosis is involved.

  18. CT-scanning of the temporal bone in an inner ear malformation

    Energy Technology Data Exchange (ETDEWEB)

    Murata, K.; Hosoi, H.; Isono, M.; Ohta, F. (Kinki Univ., Higashi-Osaka, Osaka (Japan))

    1982-05-01

    CT-scanning of the temporal bone revealed a fine contour of the inner ear anomaly in a 8-year-old boy with total deafness on the right. In the inner ear there was a globular mass with a small protrusion anteriorly and with a probably immature superior semi-circular canal. The globular mass was considered to be the utriculosaccular capsule, and the anterior protrusion to be an incipient cochlear duct. CT-scanning of the temporal bone may bring significant progress in diagnosis of inner ear anomalies. Detailed configuration of an inner ear may be shown before histological examination.

  19. Adaptive statistical iterative reconstruction: reducing dose while preserving image quality in the pediatric head CT examination

    Energy Technology Data Exchange (ETDEWEB)

    McKnight, Colin D.; Watcharotone, Kuanwong; Ibrahim, Mohannad; Christodoulou, Emmanuel; Baer, Aaron H.; Parmar, Hemant A. [University of Michigan, Department of Radiology, Ann Arbor, MI (United States)

    2014-08-15

    Over the last decade there has been escalating concern regarding the increasing radiation exposure stemming from CT exams, particularly in children. Adaptive statistical iterative reconstruction (ASIR) is a relatively new and promising tool to reduce radiation dose while preserving image quality. While encouraging results have been found in adult head and chest and body imaging, validation of this technique in pediatric population is limited. The objective of our study was to retrospectively compare the image quality and radiation dose of pediatric head CT examinations obtained with ASIR compared to pediatric head CT examinations without ASIR in a large patient population. Retrospective analysis was performed on 82 pediatric head CT examinations. This group included 33 pediatric head CT examinations obtained with ASIR and 49 pediatric head CT examinations without ASIR. Computed tomography dose index (CTDI{sub vol}) was recorded on all examinations. Quantitative analysis consisted of standardized measurement of attenuation and the standard deviation at the bilateral centrum semiovale and cerebellar white matter to evaluate objective noise. Qualitative analysis consisted of independent assessment by two radiologists in a blinded manner of gray-white differentiation, sharpness and overall diagnostic quality. The average CTDI{sub vol} value of the ASIR group was 21.8 mGy (SD = 4.0) while the average CTDI{sub vol} for the non-ASIR group was 29.7 mGy (SD = 13.8), reflecting a statistically significant reduction in CTDI{sub vol} in the ASIR group (P < 0.01). There were statistically significant reductions in CTDI for the 3- to 12-year-old ASIR group as compared to the 3- to 12-year-old non-ASIR group (21.5 mGy vs. 30.0 mGy; P = 0.004) as well as statistically significant reductions in CTDI for the >12-year-old ASIR group as compared to the >12-year-old non-ASIR group (29.7 mGy vs. 49.9 mGy; P = 0.0002). Quantitative analysis revealed no significant difference in the

  20. Colon distension and scan protocol for CT-colonography: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Boellaard, Thierry N., E-mail: t.n.boellaard@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Haan, Margriet C. de, E-mail: m.c.dehaan@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Venema, Henk W., E-mail: h.w.venema@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Stoker, Jaap, E-mail: j.stoker@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands)

    2013-08-15

    This article reviews two important aspects of CT-colonography, namely colonic distension and scan parameters. Adequate distension should be obtained to visualize the complete colonic lumen and optimal scan parameters should be used to prevent unnecessary radiation burden. For optimal distension, automatic carbon dioxide insufflation should be performed, preferably via a thin, flexible catheter. Hyoscine butylbromide is – when available – the preferred spasmolytic agent because of the positive effect on insufflation and pain/burden and its low costs. Scans in two positions are required for adequate distension and high polyp sensitivity and decubitus position may be used as an alternative for patients unable to lie in prone position. The great intrinsic contrast between air or tagging and polyps allows the use of low radiation dose. Low-dose protocol without intravenous contrast should be used when extracolonic findings are deemed unimportant. In patients suspected for colorectal cancer, normal abdominal CT scan protocols and intravenous contrast should be used in supine position for the evaluation of extracolonic findings. Dose reduction can be obtained by lowering the tube current and/or voltage. Tube current modulation reduces the radiation dose (except in obese patients), and should be used when available. Iterative reconstructions is a promising dose reducing tool and dual-energy CT is currently evaluated for its applications in CT-colonography. This review also provides our institution's insufflation procedure and scan parameters.

  1. Edema in the retropharyngeal space associated with head and neck tumors: CT imaging characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Kurihara, Noriko; Nakamura, Mamoru; Tsuda, Masashi; Saito, Haruo [National Hospital Organization Sendai Medical Center, Department of Radiology, Sendai, Miyagi (Japan); Takahashi, Shoki; Higano, Shuichi [Tohoku University, Department of Diagnostic Radiology, Sendai, Miyagi (Japan)

    2005-08-01

    To determine computed tomographic (CT) imaging characteristics of retropharygeal edema, we reviewed CT images in 18 patients with head and neck tumors. Retropharyngeal edema spread craniocaudally between soft palate and upper half of thyroid cartilage in all patients. No edema fluid extended above soft palate and below thyroid cartilage. Horizontally, it spread symmetrically in ten and asymmetrically in eight patients. Predominance in asymmetrical retropharyngeal edema was found on the same side as that of unilateral predominance both in lymph nodes enlargement and jugular vein stenosis/occlusion. All patients had edema also in other cervical spaces. Edema of retropharyngeal and other spaces fluctuated synchronously. In 14 patients, as primary lesion and/or cervical lymph nodes regressed, retropharyngeal edema disappeared or decreased. Retropharyngeal edema had some imaging characteristics. With knowledge of that, we could avoid diagnostic confusion when evaluating head and neck CT images. (orig.)

  2. Incidence of combined cranial and cervical spine injuries in patients with blunt minor trauma: are combined CT examinations of the head and cervical spine justified?

    Science.gov (United States)

    Vahldiek, Janis L; Thieme, Stefan; Hamm, Bernd; Niehues, Stefan M

    2017-07-01

    Background The use of computed tomography (CT) scans of the head and cervical spine has markedly increased in patients with blunt minor trauma. The actual likelihood of a combined injury of head and cervical spine following a minor trauma is estimated to be low. Purpose To determine the incidence of such combined injuries in patients with a blunt minor trauma in order to estimate the need to derive improved diagnostic guidelines. Material and Methods A total of 1854 patients were retrospectively analyzed. All cases presented to the emergency department and in all patients combined CT scans of head and cervical spine were conducted. For the following analysis, only 1342 cases with assured blunt minor trauma were included. Data acquisition covered age, sex, and presence of a head injury as well as presence of a cervical spine injury or both. Results Of the 1342 cases, 46.9% were men. The mean age was 65.6 years. CT scans detected a head injury in 116 patients; of these, 70 cases showed an intracranial hemorrhage, 11 cases a skull fracture, and 35 cases an intracranial hemorrhage as well as a skull fracture. An injury of the cervical spine could be detected in 40 patients. A combined injury of the head and cervical spine could be found in one patient. Conclusion The paradigm of the coincidence of cranial and cervical spine injuries should be revised in patients with blunt minor trauma. Valid imaging decision algorithms are strongly needed to clinically detect high-risk patients in order to save limited resources.

  3. An experience of detection brain disease by roentgenographic CT on head

    Energy Technology Data Exchange (ETDEWEB)

    Kobata, Daikichi [Minami Osaka Total Health Screening Center (Japan)

    1996-08-01

    MRI and MRA are recommended today from the standpoint of sensitivity for the detraction of asymptomatic brain disease, and roentgenographic CT on head is not recommended. Under certain circumstances, however, having recently been given an opportunity of detecting brain disease by means of roentgenographic CT on head, we make a report of the diagnostic results. The examinees were the staff members of a non-profit organization consisting of 62 men and 56 women whose age was 48.6 years on the average. Asymptomatic brain disease was found in 6 cases including 1 case of cerebral infarction, 1 case of calcification of cerebral vascular wall and 1 case of cranial osteoma with a suspicion of Gardner syndrome. Incidentally, there were 31 cases with a complaint of headache, 20 cases of hypertension and 3 cases with a past history of head trauma. After such findings were obtained, guidance was provided to each of them. (author)

  4. Accessible or Inaccessible? Diagnostic Efficacy of CT-Guided Core Biopsies of Head and Neck Masses

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, Jane D., E-mail: janecunningham0708@gmail.com; McCusker, Mark W.; Power, Sarah; PearlyTi, Joanna; Thornton, John; Brennan, Paul; Lee, Michael J.; O’Hare, Alan; Looby, Seamus [Beaumont Hospital, Department of Radiology (Ireland)

    2015-04-15

    PurposeTissue sampling of lesions in the head and neck is challenging due to complex regional anatomy and sometimes necessitates open surgical biopsy. However, many patients are poor surgical candidates due to comorbidity. Thus, we evaluated the use of CT guidance for establishing histopathological diagnosis of head and neck masses.MethodsAll consecutive patients (n = 22) who underwent CT-guided core biopsy of head or neck masses between April 2009 and August 2012 were retrospectively reviewed using the departmental CT interventional procedures database. The indication for each biopsy performed was to establish or exclude a diagnosis of neoplasia in patients with suspicious head or neck lesions found on clinical examination or imaging studies. Patients received conscious sedation and 18 G, semiautomated core needle biopsies were performed by experienced neuroradiologists using 16-slice multidetector row CT imaging guidance (Somatom Definition Siemens Medical Solutions, Germany). Histopathology results of each biopsy were analysed.ResultsSixteen of 22 biopsies that were performed (73 %) yielded a pathological diagnosis. Anatomic locations biopsied included: masticator (n = 7), parapharyngeal (n = 3), parotid (n = 3), carotid (n = 3), perivertebral (n = 3), pharyngeal (n = 2), and retropharyngeal (n = 1) spaces. Six biopsies (27 %) were nondiagnostic due to inadequate tissue sampling, particularly small biopsy sample size and failure to biopsy the true sampling site due to extensive necrosis. No major complications were encountered.ConclusionsThe use of CT guidance to perform core biopsies of head and neck masses is an effective means of establishing histopathological diagnosis and reduces the need for diagnostic open surgical biopsy and general anaesthesia.

  5. CT scan in diagnosis of pituitary adenomas, 5. CT findings of GH secreting adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Sakoda, K.; Yonezawa, M.; Gen, M. (Hiroshima Univ. (Japan). School of Medicine)

    1981-10-01

    Clinical findings and radiological findings in 19 cases of GH secreting adenoma were reported. In diagnosis of GH secreting adenoma, conventional radiography and computed tomography of the sella turcica are useful. The CT of this kind of adenomas shows a characteristically higher x-ray absorption coefficient than other adenomas.

  6. The Impact of Sources of Variability on Parametric Response Mapping of Lung CT Scans.

    Science.gov (United States)

    Boes, Jennifer L; Bule, Maria; Hoff, Benjamin A; Chamberlain, Ryan; Lynch, David A; Stojanovska, Jadranka; Martinez, Fernando J; Han, Meilan K; Kazerooni, Ella A; Ross, Brian D; Galbán, Craig J

    2015-09-01

    Parametric response mapping (PRM) of inspiration and expiration computed tomography (CT) images improves the radiological phenotyping of chronic obstructive pulmonary disease (COPD). PRM classifies individual voxels of lung parenchyma as normal, emphysematous, or nonemphysematous air trapping. In this study, bias and noise characteristics of the PRM methodology to CT and clinical procedures were evaluated to determine best practices for this quantitative technique. Twenty patients of varying COPD status with paired volumetric inspiration and expiration CT scans of the lungs were identified from the baseline COPD-Gene cohort. The impact of CT scanner manufacturer and reconstruction kernels were evaluated as potential sources of variability in PRM measurements along with simulations to quantify the impact of inspiration/expiration lung volume levels, misregistration, and image spacing on PRM measurements. Negligible variation in PRM metrics was observed when CT scanner type and reconstruction were consistent and inspiration/expiration lung volume levels were near target volumes. CT scanner Hounsfield unit drift occurred but remained difficult to ameliorate. Increasing levels of image misregistration and CT slice spacing were found to have a minor effect on PRM measurements. PRM-derived values were found to be most sensitive to lung volume levels and mismatched reconstruction kernels. As with other quantitative imaging techniques, reliable PRM measurements are attainable when consistent clinical and CT protocols are implemented.

  7. "Bottle Brush Sign"-Spinal Meningeal Disease on 18F-FDG PET-CT Scan.

    Science.gov (United States)

    Riaz, Saima; Naz, Fozia; Bashir, Humayun; Niazi, Imran Khalid

    2016-09-01

    A 30-year-old man with a history of stage IV AE diffuse large cell lymphoma of left proximal humerus presented with new onset lower limb weakness at completion of chemotherapy. The F-FDG PET-CT scan showed increased intraspinal uptake from T12 to S1 vertebrae with unique "bottle brush" appearance in keeping with spinal meningeal disease. The leptomeningeal disease was further confirmed on correlative MRI scan.

  8. Interactive lung segmentation in abnormal human and animal chest CT scans

    Energy Technology Data Exchange (ETDEWEB)

    Kockelkorn, Thessa T. J. P., E-mail: thessa@isi.uu.nl; Viergever, Max A. [Image Sciences Institute, University Medical Center Utrecht, 3584 CX Utrecht (Netherlands); Schaefer-Prokop, Cornelia M. [Department of Radiology, Meander Medical Centre, 3813 TZ Amersfoort, The Netherlands and Diagnostic Image Analysis Group, Radboud University Nijmegen Medical Centre, 6525 GA Nijmegen (Netherlands); Bozovic, Gracijela [Center for Diagnostic Imaging and Physiology, Skåne University Hospital, Lund University, SE-221 85 Lund (Sweden); Muñoz-Barrutia, Arrate [Cancer Imaging Laboratory, Center for Applied Medical Research, University of Navarra, ES-31008 Pamplona, Navarra (Spain); Rikxoort, Eva M. van [Diagnostic Image Analysis Group, Radboud University Nijmegen Medical Centre, 6525 GA Nijmegen (Netherlands); Brown, Matthew S. [Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, David Geffen School of Medicine at UCLA, University of California, Los Angeles, California 90024 (United States); Jong, Pim A. de [Department of Radiology, University Medical Center Utrecht, 3584 CX Utrecht (Netherlands); Ginneken, Bram van [Diagnostic Image Analysis Group, Radboud University Nijmegen Medical Centre, 6525 GA Nijmegen (Netherlands); Image Sciences Institute, University Medical Center Utrecht, 3584 CX Utrecht (Netherlands)

    2014-08-15

    Purpose: Many medical image analysis systems require segmentation of the structures of interest as a first step. For scans with gross pathology, automatic segmentation methods may fail. The authors’ aim is to develop a versatile, fast, and reliable interactive system to segment anatomical structures. In this study, this system was used for segmenting lungs in challenging thoracic computed tomography (CT) scans. Methods: In volumetric thoracic CT scans, the chest is segmented and divided into 3D volumes of interest (VOIs), containing voxels with similar densities. These VOIs are automatically labeled as either lung tissue or nonlung tissue. The automatic labeling results can be corrected using an interactive or a supervised interactive approach. When using the supervised interactive system, the user is shown the classification results per slice, whereupon he/she can adjust incorrect labels. The system is retrained continuously, taking the corrections and approvals of the user into account. In this way, the system learns to make a better distinction between lung tissue and nonlung tissue. When using the interactive framework without supervised learning, the user corrects all incorrectly labeled VOIs manually. Both interactive segmentation tools were tested on 32 volumetric CT scans of pigs, mice and humans, containing pulmonary abnormalities. Results: On average, supervised interactive lung segmentation took under 9 min of user interaction. Algorithm computing time was 2 min on average, but can easily be reduced. On average, 2.0% of all VOIs in a scan had to be relabeled. Lung segmentation using the interactive segmentation method took on average 13 min and involved relabeling 3.0% of all VOIs on average. The resulting segmentations correspond well to manual delineations of eight axial slices per scan, with an average Dice similarity coefficient of 0.933. Conclusions: The authors have developed two fast and reliable methods for interactive lung segmentation in

  9. Reduction scan time pitch for media measurement procedures ITV in lung cancer with CT-CT fusion; Reduccion de pitch para scantime medios en procedimientos de medida de ITV en cancer de pulmon con fusion CT-CT

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez Miranda, S.; Ramirez Gutierrez, Y.; Rodriguez Alarcon, C.; Herrador Cordoba, M.

    2011-07-01

    The evolution of CT technology has led to the non-specific scanners for radiotherapy the scan time maximum is reduced to 2 seconds. This forces us to change the procedure for obtaining similar results.

  10. Investigation of the potential causes of partial scan artifacts in dynamic CT myocardial perfusion imaging

    Science.gov (United States)

    Tao, Yinghua; Speidel, Michael; Szczykutowicz, Timothy; Chen, Guang-Hong

    2014-03-01

    In recent years, there have been several findings regarding CT number variations (partial scan artifact or PSA) across time in dynamic myocardial perfusion studies with short scan gated reconstruction. These variations are correlated with the view angle range corresponding to the short scan acquisition for a given cardiac phase, which can vary from one cardiac cycle to another due to the asynchrony between heart rate and gantry rotation speed. In this study, we investigate several potential causes of PSA, including noise, beam hardening and scatter, using numerical simulations. In addition, we investigate partial scan artifact in a single source 64-slice diagnostic CT scanner in vivo data sets, and report its effect on perfusion analysis. Results indicated that among all three factors investigated, scatter can cause obvious partial scan artifact in dynamic myocardial perfusion imaging. Further, scatter is a low frequency phenomenon and is not heavily dependent on the changing contrasts, as both the frequency method and the virtual scan method are effective in reducing partial scan artifact. However, PSA does not necessarily lead to different blood volume maps compared to the full scan, because these maps are usually generated with a curve fitting procedure.

  11. Dissecting aneurysm of the cervical internal carotid artery. Cervical CT scan findings and treatment - case report

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Yoshihiro; Itoyama, Youichi; Fukumura, Akinobu; Matsukado, Yasuhiko; Kodama, Takafumi

    1987-06-01

    On lifting a heavy case, a 51-year-old male experienced a sudden onset of headache with giddiness and clouded vision. A week later, vertigo and right hand numbness were added to his symptoms. The next day anisocoria (right > left) and dilation of the left retinal veins were noted. Cranial computed tomography (CT) scan appeared normal and there were no other remarkable neurological findings. The patient was treated conservatively for cerebral infarction, however, the headache worsened and diplopia occurred. Neurological examination on admission revealed nothing unusual except for left Horner's syndrome. Physical examination showed a palpable sausage-like painless tumor on the left side of the neck. Angiography showed a narrowing of the internal carotid artery in the cervical region with a small dissecting aneurysm at the C3 level. Cervical CT scan at the upper C3 level showed a low density lunar defect in the high density section of the enlarged left internal carotid artery. The patient was operated on by superficial temporal artery-middle cerebral artery anastomosis to increase the intracranial blood flow. Postoperatively the symptoms were quickly relieved. Angiography 1 month later showed less narrowing of the carotid artery, though the dissecting aneurysm still remained. Postoperative cervical CT scan showed the left internal carotid artery to be of normal size. The patient returned to his work in normal condition 2 months later. It is emphasized that cervical CT scan may be useful in the diagnosis of this unusual type of cervical dissecting aneurysm.

  12. Preliminary report on a new mode of CT-scanning of the thorax

    NARCIS (Netherlands)

    Veiga-Pires, J.A.; Kaiser, M.C.

    1980-01-01

    The A.A. advocate a “longitudino-axial” mode of CT-scanning in examinations of the thorax and suggest it as the standard mode in children and adults of small stature. The full development of the method is at present limited by the design of both hardware and software of the current generations of

  13. 3D quantification of soil structure and functioning based on PET and CT scanning techniques

    DEFF Research Database (Denmark)

    Garbout, Amin

    . The processed measurements show some expected and a few unexpected effects (or lack of effects) on different characteristics of soil structure. The combination of CT and PET scanning in an air plant soil controller system revealed some very interesting research possibilities. Interactions between soil structure...

  14. Study Finds Small Increase in Cancer Risk after Childhood CT Scans

    Science.gov (United States)

    A study published in the June 6, 2012, issue of The Lancet shows that radiation exposure from computed tomography (CT) scans in childhood results in very small but increased risks of leukemia and brain tumors in the first decade after exposure.

  15. CT-scan bij stomp buiktrauma bij kinderen : veel stralen en weinig opbrengst?

    NARCIS (Netherlands)

    Nellensteijn, David R; El Moumni, Mostafa; Greuter, Marcel J W; Kneyber, Martin C J; Hulscher, Jan B F

    2013-01-01

    Blunt abdominal trauma in children occurs fairly frequently. Although computed tomography scanning is considered by many to be the gold standard, in children who are hemodynamically stable, CT images do not usually result in new perspectives that lead to changes in treatment management. However, the

  16. Utility of CT scan for the diagnosis of chest wall tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, A.; Le Breton, C.; Tassart, M.; Korzec, J.; Bigot, J.M.; Carette, M.F. [Department of Radiology, Tenon Hospital, Paris (France)

    1999-10-01

    The objective of this study was to determine the utility of CT scan findings for the diagnosis of chest wall tuberculosis, excluding the spine. We reviewed 15 patients (13 Africans and 2 Indians) with chest wall tuberculosis, retrospectively. The radiologic examination consisted of a plain X-ray and a CT scan of the chest for each patient. The site of disease was the rib in 13 patients or the body of the sternum in 2 patients. One rib was involved in 11 patients, 2 contiguous ribs (one site) in 2 patients, and bilateral disease (two sites) was observed in the remaining patient. The 14 rib sites involved the posterior arc or costovertebral joint in 11 cases, the anterior arc in 2 cases, and the anterior and middle arc in 1 case. The CT scan findings were an abscess (n = 14) or a soft tissue mass (n = 2), osteolytic lesions (n = 13), periosteal reaction (n = 10), and sequestrum (n = 14). Bone sclerosis was observed only in 3 cases of rib involvement. The association of a soft tissue abscess, an osteolytic lesion, and sequestrum, especially in immigrants to France, suggests chest wall tuberculosis on CT scan. (orig.) With 5 figs., 2 tabs., 11 refs.

  17. Implant planning and placement using optical scanning and cone beam CT technology

    NARCIS (Netherlands)

    J.M. van der Zel

    2008-01-01

    There is a growing interest in minimally invasive implant therapy as a standard prosthodontic treatment, providing complete restoration of occlusal function. A new treatment method (CADDIMA), which combines both computerized tomographic (CT) and optical laser-scan data for planning and design of sur

  18. Influence of cone beam CT scanning parameters on grey value measurements at an implant site

    NARCIS (Netherlands)

    Parsa, A.; Ibrahim, N.; Hassan, B.; Motroni, A.; van der Stelt, P.; Wismeijer, D.

    2013-01-01

    Objectives: The aim of this study was to determine the grey value variation at the implant site with different scan settings, including field of view (FOV), spatial resolution, number of projections, exposure time and dose selections in two cone beam CT (CBCT) systems and to compare the results with

  19. Virtual teeth: a 3D method for editing and visualizing small structures in CT scans

    DEFF Research Database (Denmark)

    Bro-Nielsen, Morten; Larsen, Per; Kreiborg, Sven

    1996-01-01

    The paper presents an interactive method for segmentation and visualization of small structures in CT scans. A combination of isosurface generation, spatial region growing and interactive graphics tools are used to extract small structures interactively. A practical example of segmentation of the...

  20. Selection of colon cancer patients for neoadjuvant chemotherapy by preoperative CT scan

    DEFF Research Database (Denmark)

    Nørgaard, Anne; Dam, Claus; Jakobsen, Anders

    2014-01-01

    invasion (ETI), nodal stage (N-stage), extramural venous invasion (EVI) and the distance from tumor to nearest retroperitoneal fascia (DRF) were retrospectively assessed on the CT scan and compared blindly with the results of the pathological examination, including evaluation of the criteria for adjuvant...

  1. Correlation between the Degree and Severity of Symptoms and CT scan Changes in Chronic Rhinosinusitis (CRS

    Directory of Open Access Journals (Sweden)

    H. Moghaddasi

    2008-01-01

    Full Text Available Background/Objective: find out whether any correlation exists between the degree and severity of symptoms as assessed by the SNOT-20 questionnaire and CT scan changes as graded by Lund-Mackay scoring system in chronic rhinosinusitis (CRS."nPatients and Methods: Fifties patients attending the otolaryngology department and diagnosed with CRS were prospectively entered in this study. All patients had their CT scans graded by using the Lund-Mackay  with the sino-nasal outcome questionnaire (SNOT-20. Correlation analysis was conducted to determine whether the CT scan stage as assigned by Lund Mackay staging system correlated with the SNOT-20 scores."nResults: The mean age of our patients was 32.4±8.5 and 32(64% of them were male and 18(36% were female. The mean SNOT-20 was 45±8.7 (29-67 and the mean Lund-Mackay sinus score was 18.5±5 (8- 24.The mean SNOT-20 score was higher for postnasal drip (PND and facial pain, and the lowest mean scores were for dizziness and ear pain. The Pearson's correlation coefficient confirmed that there was a good correlation between SNOT-20 scores and CT scores (Pearson correlation coefficient 0.77; P value, 0.0001."nConclusion: Patients with higher symptom scores are more likely to have CT imaging evidence of rhinosinusitis. In patients with isolated sleep or systematic symptoms, the likelihood of rhinosinusitis is less, even if symptoms are severe. Therefore, in these patients, sinus CT-scan should be considered before treatment to establish the diagnosis of chronic rhinosinusitis due to that a number of these patients may be doing not have rhinosinusitis.

  2. Automated Segmentation and Retrieval System for CT Head Images

    Science.gov (United States)

    Tong, Hau-Lee; Ahmad Fauzi, Mohammad Faizal; Komiya, Ryoichi

    In this paper, automatic segmentation and retrieval of medical images are presented. For the segmentation, different unsupervised clustering techniques are employed to partition the Computed Tomography (CT) brain images into three regions, which are the abnormalities, cerebrospinal fluids (CSF) and brain matters. The novel segmentation method proposed is a dual level segmentation approach. The first level segmentation, which purpose is to acquire abnormal regions, uses the combination of fuzzy c-means (FCM) and k-means clustering. The second level segmentation performs either the expectation-maximization (EM) technique or the modified FCM with population-diameter independent (PDI) to segment the remaining intracranial area into CSF and brain matters. The system automatically determines which algorithm to be utilized in order to produce optimum results. The retrieval of the medical images is based on keywords such as "no abnormal region", "abnormal region(s) adjacent to the skull" and "abnormal region(s) not adjacent to the skull". Medical data from collaborating hospital are experimented and promising results are observed.

  3. 实验猕猴头颈部CT影像学观察%Observation of head CT tomography the laboratorial rhesus monkey

    Institute of Scientific and Technical Information of China (English)

    范春梅; 李志雄; 周建华

    2012-01-01

    5 male and 5 female health adult monkeys aged 6-10 years were selected for head CT tomography. After general anesthesia, the monkeys were placed on the table-board of CT in supine position and the volume data were collected. Scanned images of head were obtained by CT tomography.The scan obtained volume data were restructured into 2D or 3D images using CT image post-processing technology. Results The head structure Continuous CT tomography images and restructured images of living rhesus monkey were obtained, From the CT images the structure of tissues and organs of rhesus monkey's head can be clearly displayed and distinguished, such as cervical spine, skull and optic nerve. But the distinction between the cerebral gray matter and white matter and soft tissue are not so well. The basic information of the head CT tomography images of healthy adult rhesus monkey is established, which provides a reference for research of CT imaging of rhesus monkey, research of anatomy, the clinical diagnosis of the disease and the scientific experiments.%选择实验猕猴10只,雌雄各半,年龄6~10岁;全身麻醉后,置于CT诊断床上,取头前尾后仰卧位,采用平扫进行容积数据采集,获取正常猕猴头颈部CT影像图片。利用CT图像后处理技术对扫描获得的容积数据进行2D或3D的图像重组处理获得了实验猕猴头部结构CT连续断层扫描图像和重建图像。CT影像能够较好的显示及分辨猕猴头颈部的组织器官结构,如颈椎、颅骨、视神经等;但对脑的灰、白质的区分和软组织的分辨不够理想。试验获得了正常成年猕猕头颈部的影像学基础资料,为CT技术在猕猴影像学研究、解剖学研究、疾病的临床诊断及科学实验方面的应用,提供了参考。

  4. Value of Bone Scan in Addition to F-18 FDG PET/CT and Characteristics of Discordant Lesions between F-18 FDG PET/CT and Bone Scan in the Spinal Bony Metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Sung Min; Nam, Hyun Yeol; Kim, In Ju; Kim, Yong Ki [Pusan National University Hospital, Pusan (Korea, Republic of); Kim, Ju Sung [College of Medical Life Science, Silla University, Pusan (Korea, Republic of)

    2008-06-15

    Our purpose was to evaluate spinal bony metastasis which could be missed on an F-18 FDG PET/CT (FDG PET/CT) alone, and to characterize discordant metastatic lesions between FDG PET/CT and bone scan. FDG PET/CT and bone scans of 43 patients with spinal bony metastasis were analyzed retrospectively. A McNemar test was performed comparing the FDG PET/CT alone to the FDG PET/CT plus bone scan in the spinal bony metastases. A one-way chi-square test was performed to characterize the metastases that were missed on the FDG PET/CT alone. To evaluate discordant lesions between FDG PET/CT and bone scan, we performed logistic regression analyses. The independent variables were sites (cervical, thoracic, and lumbar), size (large and small), and maximum SUVs, and the dependant variable was bone scan uptake (positive and negative MDP uptake). A significant difference was found between the FDG PET/CT alone and the FDG PET/CT combined with the bone scan (p<0.01). Using the FDG PET/CT only, diffuse osteoblastic metastasis was missed with a significantly higher frequency (p=0.04). In the univariate analysis, cervical vertebra and small size were related to negative MDP uptake, and thoracic vertebra and large size were related to positive MDP uptake. However, in the multivariate analysis, only the large size was related to positive MDP uptake. A bone scan in addition to the FDG PET/CT increased the ability to evaluate spinal bony metastases, especially for diffuse osteoblastic metastasis. Large metastasis was related to positive bone scan uptake in spinal bony metastasis.

  5. Contrast enhancement characteristics of hepatocellular carcinoma on two-phase dynamic scan with spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Dae Young; Choi, Byung Ihn; Han, Joon Koo; Han, Man Chung [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

    1994-12-15

    The purpose of this study was to characterize the enhancing patterns of hepatocellular carcinoma (HCC) on two-phase dynamic incremental liver scan with spiral CT. Two-phase dynamic incremental liver scan using spiral CT was performed on 230 lesions in 107 patients with HCC. CT scanning was performed with a table speed of 13 mm/sec and a section thickness of 10 mm; 120 mL of contrast medium was injected intravenously with a automatic injector at the rate of 3 mL/sec. CT scans were started 35 sec(early phase) and 3 min(delayed phase) after beginning injection of contrast medium. The tumors were divided into 2 groups according to size({<=}3cm and > 3cm), the contrast enhancement patterns of HCCs and capsules in the early and delayed phases were analyzed in each group. Most of HCCs appeared as high-attenuating lesions in the early phase(75% in tumors smaller than 3cm and 61 % in tumors larger than 3cm), and as low-attenuating lesions in the delayed phase(68% in tumors smaller than 3cm and 90% in tumors larger than 3cm). Forty-eight percent of HCCs smaller than 3cm and 58% of HCCs larger than 3 cm were high-attenuating in the early phase and low-attenuating in the delayed phase. Thirty-two percent of capsules were low- or iso-attenuating in the early phase and high-attenuating in the delayed phase. Capsules were demonstrated in 22% in HCCs smaller than 3cm and 67% in HCCs larger than 3 cm (p <. 01). Two-phase dynamic scan with spiral CT is useful in the diagnosis of HCC because of a precise display of hemodynamic characteristics of HCCs.

  6. Analysis of chromosome translocation frequency after a single CT scan in adults.

    Science.gov (United States)

    Abe, Yu; Miura, Tomisato; Yoshida, Mitsuaki A; Ujiie, Risa; Kurosu, Yumiko; Kato, Nagisa; Katafuchi, Atsushi; Tsuyama, Naohiro; Kawamura, Fumihiko; Ohba, Takashi; Inamasu, Tomoko; Shishido, Fumio; Noji, Hideyoshi; Ogawa, Kazuei; Yokouchi, Hiroshi; Kanazawa, Kenya; Ishida, Takashi; Muto, Satoshi; Ohsugi, Jun; Suzuki, Hiroyuki; Ishikawa, Tetsuo; Kamiya, Kenji; Sakai, Akira

    2016-06-01

    We recently reported an increase in dicentric chromosome (DIC) formation after a single computed tomography (CT) scan (5.78-60.27 mSv: mean 24.24 mSv) and we recommended analysis of 2000 metaphase cells stained with Giemsa and centromere-FISH for dicentric chromosome assay (DCA) in cases of low-dose radiation exposure. In the present study, we analyzed the frequency of chromosome translocations using stored Carnoy's-fixed lymphocyte specimens from the previous study; these specimens were from 12 patients who were subject to chromosome painting of Chromosomes 1, 2 and 4. Chromosomes 1, 2 and 4 were analyzed in ∼5000 cells, which is equivalent to the whole-genome analysis of almost 2000 cells. The frequency of chromosome translocation was higher than the number of DICs formed, both before and after CT scanning. The frequency of chromosome translocations tended to be higher, but not significantly higher, in patients with a treatment history compared with patients without such a history. However, in contrast to the results for DIC formation, the frequency of translocations detected before and after the CT scan did not differ significantly. Therefore, analysis of chromosome translocation may not be a suitable assay for detecting chromosome aberrations in cases of low-dose radiation exposure from a CT scan. A significant increase in the frequency of chromosome translocations was not likely to be detected due to the high baseline before the CT scan; the high and variable frequency of translocations was probably due to multiple confounding factors in adults.

  7. Thromboembolic Complications Following Spine Surgery Assessed with Spiral CT Scans: DVT/PE Following Spine Surgery.

    Science.gov (United States)

    Kim, Han Jo; Walcott-Sapp, Sarah; Adler, Ronald S; Pavlov, Helene; Boachie-Adjei, Oheneba; Westrich, Geoffrey H

    2011-02-01

    Spine surgery is associated with a significant risk of postoperative pulmonary embolism (PE) and/or deep vein thrombosis (DVT). The goal of this study was to determine which symptoms and risk factors were associated with spiral CT scans positive for PE and/or DVT in the postoperative spine surgery patient. We conducted a retrospective review of all spine patients who underwent a postoperative CT to rule out PE during the period of March 2004-February 2006. The type of surgical procedure, risk factors, symptoms prompting scan ordering, anticoagulation, and treatment were recorded. Logistic regression models were used to determine significant predictors of a positive CT in this patient population. Of the 3,331 patients that had spine surgery during the study period, 130 (3.9%) had a spiral CT scan to rule out PE and/or proximal DVT. Thirty-three of the 130 (25.4%) CT scans were positive for PE only, five (3.8%) for PE and DVT, and three (2.3%) for DVT only. Only 24.5% (32) patients had risk factors for thromboembolic disease, and of these, a history of PE and/or DVT was the only significant risk factor for a positive scan (p = 0.03). No presenting symptoms or demographic variables were noted to have a significant association with PE and/or DVT. The type of surgical procedure (i.e., anterior, posterior, and percutaneous) was not associated with an increased risk for PE and/or DVT. Patients who are undergoing spine surgery with a history of thromboembolic disease should be carefully monitored postoperatively and may benefit from more aggressive prophylaxis.

  8. Self-guided clinical cases for medical students based on postmortem CT scans of cadavers.

    Science.gov (United States)

    Bohl, Michael; Francois, Webster; Gest, Thomas

    2011-07-01

    In the summer of 2009, we began full body computed tomography (CT) scanning of the pre-embalmed cadavers in the University of Michigan Medical School (UMMS) dissection lab. We theorized that implementing web-based, self-guided clinical cases based on postmortem CT (PMCT) scans would result in increased student appreciation for the clinical relevance of anatomy, increased knowledge of cross-sectional anatomy, and increased ability to identify common pathologies on CT scans. The PMCT scan of each cadaver was produced as a DICOM dataset, and then converted into a Quicktime movie file using Osirix software. Clinical cases were researched and written by the authors, and consist of at least one Quicktime movie of a PMCT scan surrounded by a novel navigation interface. To assess the value of these clinical cases we surveyed medical students at UMMS who are currently using the clinical cases in their coursework. Students felt the clinical cases increased the clinical relevance of anatomy (mean response 7.77/10), increased their confidence finding anatomical structures on CT (7.00/10), and increased their confidence recognizing common pathologies on CT (6.17/10). Students also felt these clinical cases helped them synthesize material from numerous courses into an overall picture of a given disease process (7.01/10). These results support the conclusion that our clinical cases help to show students why the anatomy they are learning is foundational to their other coursework. We would recommend the use of similar clinical cases to any medical school utilizing cadaver dissection as a primary teaching method in anatomy education.

  9. Have CT--will travel: to boldly go where no scan has gone before.

    Science.gov (United States)

    Schwamm, Lee H; Starkman, Sidney

    2013-01-08

    In 1962, a new English rock-and-roll band named The Beatles signed a recording contract with Electric & Music Industries (EMI). The Beatles were so financially successful that EMI was able to fund research and development in other divisions of the company; in particular, the work of an enterprising young engineer named Godfrey Hounsfield. His groundbreaking work in x-ray imaging produced the first commercially available head-only CT scanner, and a Nobel Prize.

  10. WE-EF-207-05: Monte Carlo Dosimetry for a Dedicated Cone-Beam CT Head Scanner

    Energy Technology Data Exchange (ETDEWEB)

    Sisniega, A; Zbijewski, W; Xu, J; Dang, H; Stayman, J W; Aygun, N; Koliatsos, V E; Siewerdsen, J H [Johns Hopkins University, Balitmore, MD (United States); Wang, X; Foos, D H [Carestream Health, Rochester, NY (United States)

    2015-06-15

    Purpose: Cone-Beam CT (CBCT) is an attractive platform for point-of-care imaging of traumatic brain injury and intracranial hemorrhage. This work implements and evaluates a fast Monte-Carlo (MC) dose estimation engine for development of a dedicated head CBCT scanner, optimization of acquisition protocols, geometry, bowtie filter designs, and patient-specific dosimetry. Methods: Dose scoring with a GPU-based MC CBCT simulator was validated on an imaging bench using a modified 16 cm CTDI phantom with 7 ion chamber shafts along the central ray for 80–100 kVp (+2 mm Al, +0.2 mm Cu). Dose distributions were computed in a segmented CBCT reconstruction of an anthropomorphic head phantom with 4×10{sup 5} tracked photons per scan (5 min runtime). Circular orbits with angular span ranging from short scan (180° + fan angle) to full rotation (360°) were considered for fixed total mAs per scan. Two aluminum filters were investigated: aggressive bowtie, and moderate bowtie (matched to 16 cm and 32 cm water cylinder, respectively). Results: MC dose estimates showed strong agreement with measurements (RMSE<0.001 mGy/mAs). A moderate (aggressive) bowtie reduced the dose, per total mAs, by 20% (30%) at the center of the head, by 40% (50%) at the eye lens, and by 70% (80%) at the posterior skin entrance. For the no bowtie configuration, a short scan reduced the eye lens dose by 62% (from 0.08 mGy/mAs to 0.03 mGy/mAs) compared to full scan, although the dose to spinal bone marrow increased by 40%. For both bowties, the short scan resulted in a similar 40% increase in bone marrow dose, but the reduction in the eye lens was more pronounced: 70% (90%) for the moderate (aggressive) bowtie. Conclusions: Dose maps obtained with validated MC simulation demonstrated dose reduction in sensitive structures (eye lens and bone marrow) through combination of short-scan trajectories and bowtie filters. Xiaohui Wang and David Foos are employees of Carestream Health.

  11. Benefit of cerebrospinal fluid spectrophotometry in the assessment of CT scan negative suspected subarachnoid haemorrhage: a diagnostic accuracy study.

    Science.gov (United States)

    Hann, Angus; Chu, Kevin; Greenslade, Jaimi; Williams, Julian; Brown, Anthony

    2015-01-01

    This study aimed to determine if performing cerebrospinal fluid spectrophotometry in addition to visual inspection detects more ruptured cerebral aneurysms than performing cerebrospinal fluid visual inspection alone in patients with a normal head CT scan but suspected of suffering an aneurysmal subarachnoid haemorrhage (SAH). We performed a single-centre retrospective study of patients presenting to the emergency department of a tertiary hospital who underwent both head CT scan and lumbar puncture to exclude SAH. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of an approach utilising both spectrophotometry and visual inspection (combined approach) was compared to visual inspection alone. A total of 409 patients (mean age 37.8 years, 56.2% female) were recruited and six (1.5%) had a cerebral aneurysm on angiography. The sensitivity of visual inspection was 50% (95% confidence interval [CI]: 12.4-82.6%), specificity was 99% (95% CI: 97.5-99.7%), PPV was 42.9% (95% CI: 10.4-81.3%) and NPV was 99.2% (95% CI: 97.8-99.8%). The combined approach had a sensitivity of 100% (95% CI: 54.1-100%), specificity of 79.7% (95% CI: 75.4-83.5%), PPV of 6.8% (95% CI: 2.6-14.3%) and a NPV of 100% (95% CI: 98.8-100%). The sensitivity of the combined approach was not significantly different to that of visual inspection alone (p=0.25). Visual inspection had a significantly higher specificity than the combined approach (p<0.01). The combined approach detected more cases of aneurysmal SAH than visual inspection alone, however the difference in sensitivity was not statistically significant. Visual xanthochromia should prompt angiography because of a superior specificity and PPV. Due to its reduced sensitivity, caution should be applied when using only visual inspection of the supernatant.

  12. Assessment value of quantitative indexes of pancreatic CT perfusion scanning for malignant degree of pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Jiang-Xia Lei

    2016-01-01

    Objective:To analyze the assessment value of the quantitative indexes of pancreatic CT perfusion scanning for malignant degree of pancreatic cancer.Methods:A total of 58 patients with space-occupying pancreatic lesions were divided into 20 patients with pancreatic cancer and 38 patients with benign pancreatic lesions after pancreatic CT perfusion. Patients with pancreatic cancer received palliative surgery, and the cancer tissue and para-carcinoma tissue specimens were collected during operation. The differences in pancreatic CT perfusion scanning parameter values and serum tumor marker levels were compared between patients with pancreatic cancer and patients with benign pancreatic lesions, mRNA expression levels of malignant molecules in pancreatic cancer tissue and para-carcinoma tissue were further determined, and the correlation between pancreatic CT perfusion scanning parameter values and malignant degree of pancreatic cancer was analyzed.Results:CT perfusion scanning BF, BV and Per values of patients with pancreatic cancer were lower than those of patients with benign pancreatic lesions; serum CA19-9, CEA, CA125 and CA242 levels were higher than those of patients with benign pancreatic lesions (P<0.05); mRNA expression levels of Bcl-2, Bcl-xL andsurvivin in pancreatic cancer tissue samples were higher than those in para-carcinoma tissue samples, and mRNA expression levels ofP53 andBax were lower than those in para-carcinoma tissue samples (P<0.05); CT perfusion scanning parameters BF, BV and Per values of patients with pancreatic cancer were negatively correlated with CA19-9, CEA, CA125 and CA242 levels in serum as well as mRNA expression levels ofBcl-2, Bcl-xL and survivinin pancreatic cancer tissue, and positively correlated with mRNA expression levels ofP53andBaxin pancreatic cancer tissue (P<0.05).Conclusions:Pancreatic CT perfusion scanning is a reliable way to judge the malignant degree of pancreatic cancer and plays a positive role in guiding clinical

  13. CT Diagnosis of Fitz-Hugh and Curtis Syndrome: Value of the Arterial Phase Scan

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Seung Ho; Kim, Myeong Jin; Lim, Joon Seok; Kim, Joo Hee; Kim, Ki Whang [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2007-02-15

    We wanted to evaluate the role of the arterial phase (AP) together with the portal venous phase (PP) scans in the diagnosis of Fitz-Hugh-Curtis syndrome (FHCS) with using computed tomography (CT). Twenty-five patients with FHCS and 25 women presenting with non-specifically diagnosed acute abdominal pain and who underwent biphasic CT examinations were evaluated. The AP scan included the upper abdomen, and the PP scan included the whole abdomen. Two radiologists blindly and retrospectively reviewed the PP scans first and then they reviewed the AP plus PP scans. The diagnostic accuracy of FHCS on each image set was compared for each reader by analyzing the area under the receiver operating characteristic curve (Az). Weighted kappa (wk) statistics were used to measure the interobserver agreement for the presence of CT signs of the pelvic inflammatory disease (PID) on the PP images and FHCS as the diagnosis based on the increased perihepatic enhancement on both sets of images. The individual diagnostic accuracy of FHCS was higher on the biphasic images (Az = 0.905 and 0.942 for reader 1 and 2, respectively) than on the PP images alone (Az = 0.806 and 0.706, respectively). The interobserver agreement for the presence of PID on the PP images was moderate (wk = 0.530). The interobserver agreement for FHCS as the diagnosis was moderate on only the PP images (wk = 0.413), but it was substantial on the biphasic images (wk 0.719). Inclusion of the AP scan is helpful to depict the increased perihepatic enhancement, and it improves the diagnostic accuracy of FHCS on CT.

  14. CT analysis of the upper end of the femur: the asterisk sign and ischaemic bone necrosis of the femoral head.

    Science.gov (United States)

    Dihlmann, W

    1982-01-01

    In computed tomography (CT) of the head of the femur, a star-shaped structure can be seen which we refer to as the asterisk or asterisk sign. The asterisk is formed by thickened weight-bearing bone trabeculae. It can be shown by CT that the asterisk exhibits a characteristic change in ischaemic bone necrosis of the femoral head, even when the disease is in an early stage. CT of the hip joint is therefore an important examination for early diagnosis of ischaemic disease of the femoral head.

  15. A new objective method for CT triage after minor head injury--serum S100B

    DEFF Research Database (Denmark)

    Undén, Johan; Rommer, Bertil Roland

    2009-01-01

    , may be compromised by patient factors such as intoxication. Clinical studies from several research groups have shown the potential of brain biomarker S100B in this patient category. The specificity of S100B is poor, but a high sensitivity for brain damage effectively rules out relevant complications...... after MHI. Used in conjunction with existing guidelines, serum levels of S100B can accurately identify patients who do not need a CT scan after MHI. Based on 6 prospective studies comprising almost 2,000 patients with MHI, the sensitivity and negative predictive value of S100B for CT findings were 98.......2% and 99.5%, respectively, and for clinically relevant intracranial complications 100% and 100%, respectively. Integration of S100B within existing management routines can reduce the need for CT scans by 30%, resulting in improved and more efficient patient care....

  16. Pancreatic Head Mass: What Can Be Done? Diagnosis: Computed Tomography Scan

    Directory of Open Access Journals (Sweden)

    Winternitz T

    2000-09-01

    Full Text Available The diagnosis of different pancreatic diseases has recently become a recurrent problem. In cases with pancreatic head mass the main question is the differentiation between malignant and benign lesions. When a neoplasm is suspected, the main task is to judge operability. The usefulness of computed tomography imaging in the evaluation of pancreatic carcinoma has been well established. In this article the authors discuss the possibilities of computed tomography (CT in diagnostic work-up.

  17. Aphasia caused by intracerebral hemorrhage; CT-scan findings and prognosis

    Energy Technology Data Exchange (ETDEWEB)

    Furuya, Kazuhide; Segawa, Hiromu; Shiokawa, Yoshiaki; Hasegawa, Isao; Sano, Keiji (Fuji Brain Institute and Hospital, Shizuoka (Japan))

    1992-10-01

    It is generally accepted that cases of aphasia can be divided into several groups according to verbal fluency, auditory comprehension, and repetition abilities. Although many authors have studied aphasia and its location by means of a CT scan, the primary lesion on a CT scan with regard to the subtypes of aphasia still remains controversial. In this report we present our new CT classification for the syndromes of aphasia and the prognosis. Twenty-one patients with intracerebral hematoma (ICH) were followed up for more than 3 months after onset. ICH was classified according to the mode of the horizontal extension of the hematoma on a CT scan. Four lines were decided as follows: Line (a) is between the anterior horn of the lateral ventricle and the midpoint of the third ventricle; Line (b) is the vertical line to the saggital line which originates from the midpoint of the third ventricle; Line (c) is between the trigone of the lateral ventricle and the midpoint of the third ventricle. The CT classification consisted of 4 types: in Type A, ICH was located anterior to line (a); in Type B, ICH was located between line (a) and line (b); in Type C, ICH was located between line (b) and line (c); Type B+C, was a combination of Type B and Type C. Transcortical motor aphasia belonged to the Type A group. Transcortical sensory aphasia belonged to the Type B and Type B+C groups. Wernicke's and anomic aphasia belonged to the Type C group. Conduction and global aphasia belonged to the Type B+C group. Pure Broca's aphasia could not be observed in this series. Several relationships between the syndromes of aphasia and its CT findings were evident. On the other hand, the syndromes of aphasia and the degree of recovery were not correlated, except for global aphasia. (author).

  18. Noncontrast perfusion single-photon emission CT/CT scanning: a new test for the expedited, high-accuracy diagnosis of acute pulmonary embolism.

    Science.gov (United States)

    Lu, Yang; Lorenzoni, Alice; Fox, Josef J; Rademaker, Jürgen; Vander Els, Nicholas; Grewal, Ravinder K; Strauss, H William; Schöder, Heiko

    2014-05-01

    Standard ventilation and perfusion (V˙/Q˙) scintigraphy uses planar images for the diagnosis of pulmonary embolism (PE). To evaluate whether tomographic imaging improves the diagnostic accuracy of the procedure, we compared noncontrast perfusion single-photon emission CT (Q˙-SPECT)/CT scans with planar V˙/Q˙scans in patients at high risk for PE. Between 2006 and 2010, most patients referred for diagnosis of PE underwent both Q˙-SPECT/CT scan and planar V˙/Q˙scintigraphy. All scans were reviewed retrospectively by four observers; planar scans were read with modified Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) II and Prospective Investigative Study of Pulmonary Embolism Diagnosis (PISA-PED) criteria. On Q˙-SPECT/CT scan, any wedge-shaped peripheral perfusion defect occupying > 50% of a segment without corresponding pulmonary parenchymal or pleural disease was considered to show PE. The final diagnosis was established with a composite reference standard that included ECG, ultrasound of lower-extremity veins, D-dimer levels, CT pulmonary angiography (when available), and clinical follow-up for at least 3 months. One hundred six patients with cancer and mean Wells score of 4.4 had sufficient follow-up; 22 patients were given a final diagnosis of PE, and 84 patients were given a final diagnosis of no PE. According to PIOPED II, 13 studies were graded as intermediate probability. Sensitivity and specificity for PE were 50% and 98%, respectively, based on PIOPED II criteria; 86% and 93%, respectively, based on PISA-PED criteria; and 91% and 94%, respectively, based on Q˙-SPECT/CT scan. Seventy-six patients had additional relevant findings on the CT image of the Q˙-SPECT/CT scan. Noncontrast Q˙-SPECT/CT imaging has a higher accuracy than planar V˙/Q˙imaging based on PIOPED II criteria in patients with cancer and a high risk for PE.

  19. Influence of cone beam CT scanning parameters on grey value measurements at an implant site.

    Science.gov (United States)

    Parsa, A; Ibrahim, N; Hassan, B; Motroni, A; van der Stelt, P; Wismeijer, D

    2013-01-01

    The aim of this study was to determine the grey value variation at the implant site with different scan settings, including field of view (FOV), spatial resolution, number of projections, exposure time and dose selections in two cone beam CT (CBCT) systems and to compare the results with those obtained from a multislice CT system. A partially edentulous human mandibular cadaver was scanned by three CT modalities: multislice CT (MSCT) (Philips, Best, the Netherlands), and two CBCT systems: (Accuitomo 170(®), Morita, Japan) and (NewTom 5G(®), QR, Verona, Italy). Using different scan settings 36 and 24 scans were obtained from the Accuitomo and the NewTom, respectively. The scans were converted to digital imaging and communications in medicine 3 format. The analysis of the data was performed using 3Diagnosys(®) software (v. 3.1, 3diemme, Cantù, Italy) and Geomagic studio(®) 2012 (Morrisville, NC). On the MSCT scan, one probe designating the site for pre-operative implant placement was inserted. The inserted probe on MSCT was transformed to the same region on each CBCT scan using a volume-based three-dimensional registration algorithm. The mean voxel grey value of the region around the probe was derived separately for each CBCT. The influence of scanning parameters on the measured mean voxel grey values was assessed. Grey values in both CBCT systems significantly deviated from Hounsfield unit values measured with MSCT (p = 0.0001). In both CBCT systems, scan FOV and spatial resolution selections had a statistically significant influence on grey value measurements (p = 0.0001). The number of projections selection had a statistically significant influence in the Accuitomo system (p = 0.0001) while exposure time and dose selections had no statistically significant influence on grey value measurements in the NewTom (p = 0.43 and p = 0.37, respectively). Grey-level values from CBCT images are influenced by device and scanning settings.

  20. Analytic image reconstruction from partial data for a single-scan cone-beam CT with scatter correction

    Energy Technology Data Exchange (ETDEWEB)

    Min, Jonghwan; Pua, Rizza; Cho, Seungryong, E-mail: scho@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Insoo; Han, Bumsoo [EB Tech, Co., Ltd., 550 Yongsan-dong, Yuseong-gu, Daejeon 305-500 (Korea, Republic of)

    2015-11-15

    Purpose: A beam-blocker composed of multiple strips is a useful gadget for scatter correction and/or for dose reduction in cone-beam CT (CBCT). However, the use of such a beam-blocker would yield cone-beam data that can be challenging for accurate image reconstruction from a single scan in the filtered-backprojection framework. The focus of the work was to develop an analytic image reconstruction method for CBCT that can be directly applied to partially blocked cone-beam data in conjunction with the scatter correction. Methods: The authors developed a rebinned backprojection-filteration (BPF) algorithm for reconstructing images from the partially blocked cone-beam data in a circular scan. The authors also proposed a beam-blocking geometry considering data redundancy such that an efficient scatter estimate can be acquired and sufficient data for BPF image reconstruction can be secured at the same time from a single scan without using any blocker motion. Additionally, scatter correction method and noise reduction scheme have been developed. The authors have performed both simulation and experimental studies to validate the rebinned BPF algorithm for image reconstruction from partially blocked cone-beam data. Quantitative evaluations of the reconstructed image quality were performed in the experimental studies. Results: The simulation study revealed that the developed reconstruction algorithm successfully reconstructs the images from the partial cone-beam data. In the experimental study, the proposed method effectively corrected for the scatter in each projection and reconstructed scatter-corrected images from a single scan. Reduction of cupping artifacts and an enhancement of the image contrast have been demonstrated. The image contrast has increased by a factor of about 2, and the image accuracy in terms of root-mean-square-error with respect to the fan-beam CT image has increased by more than 30%. Conclusions: The authors have successfully demonstrated that the

  1. Combined {sup 18}F-FDG-PET/CT imaging of the head and neck. An approach to metal artifact correction

    Energy Technology Data Exchange (ETDEWEB)

    Schaefers, K.P. [Univ. Hospital Muenster (Germany). Dept. of Nuclear Medicine; Raupach, R. [Univ. Hospital Essen (Germany); Beyer, T. [Siemens Medical Solutions, Computed Tomography, Forchheim (Germany); Timaq medical imaging Inc, Zuerich (Switzerland)

    2006-07-01

    PET/CT imaging is particularly promising for head/neck malignancies, but dental implants lead to biased CT attenuation and PET activity values following CT-based attenuation correction (CT-AC). Objective: Here, we implement a metal artifact correction procedure (MAR) as part of the CT-AC for PET/CT imaging. Results: Phantom studies indicate a maximum quantitative bias in CT and PET of 1000 HU and 30%, which is reduced to 230 HU and 6%, respectively following MAR. These results were verified in selected patients. Conclusion: Artifacts and biases from dental implants can be reduced in PET/CT imaging by applying a simple MAR as part of the CT-AC. (orig.)

  2. Evaluation of the image quality of chest CT scans: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Martins N, P. I.; Prata M, A., E-mail: priscillainglid@gmail.com [Centro Federal de Educacao Tecnologica de Minas Gerais, Centro de Engenharia Biomedica, Av. Amazonas 5253, 30421-169 Nova Suica, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography (CT) is considered one of the most important methods of medical imaging employed nowadays, due to its non-invasiveness and the high quality of the images it is able to generate. However, the diagnostic radiation dose received by an individual over the year often exceeds the dose received on account of background radiation. Therefore, it is important to know and to control the dose distribution in the patient by varying the image acquisition parameters. The aim of this study is to evaluate the variation of the image quality of chest CT scans performed by two phantoms. In this paper, a cylindrical Polymethyl Methacrylate (PMMA) chest phantom was used and a second PMMA phantom has been developed with the same volume but an oblong shape, based on the actual dimensions of a male human thorax, in the axillary region. Ten-centimeter scans of the central area of each phantom were performed by a 16-channel Toshiba CT scanner, model Alexion. The scanning protocol employed was the radiology service protocol for chest scans. The noise survey was conducted within the image of the center slice, in five regions: one central and four peripheral areas close to the edge of the object (anterior, posterior, left and right). The recorded values showed that the oblong phantom, with a shape that is more similar to the actual human chest, has a considerably smaller noise, especially in the anterior, posterior and central regions. (Author)

  3. Combining generative and discriminative models for semantic segmentation of CT scans via active learning.

    Science.gov (United States)

    Iglesias, Juan Eugenio; Konukoglu, Ender; Montillo, Albert; Tu, Zhuowen; Criminisi, Antonio

    2011-01-01

    This paper presents a new supervised learning framework for the efficient recognition and segmentation of anatomical structures in 3D computed tomography (CT), with as little training data as possible. Training supervised classifiers to recognize organs within CT scans requires a large number of manually delineated exemplar 3D images, which are very expensive to obtain. In this study, we borrow ideas from the field of active learning to optimally select a minimum subset of such images that yields accurate anatomy segmentation. The main contribution of this work is in designing a combined generative-discriminative model which: i) drives optimal selection of training data; and ii) increases segmentation accuracy. The optimal training set is constructed by finding unlabeled scans which maximize the disagreement between our two complementary probabilistic models, as measured by a modified version of the Jensen-Shannon divergence. Our algorithm is assessed on a database of 196 labeled clinical CT scans with high variability in resolution, anatomy, pathologies, etc. Quantitative evaluation shows that, compared with randomly selecting the scans to annotate, our method decreases the number of training images by up to 45%. Moreover, our generative model of body shape substantially increases segmentation accuracy when compared to either using the discriminative model alone or a generic smoothness prior (e.g. via a Markov Random Field).

  4. A novel sedimentological method based on CT-scanning: Use for tomographic characterization of the Galicia Interior Basin

    Science.gov (United States)

    Mena, Anxo; Francés, Guillermo; Pérez-Arlucea, Marta; Aguiar, Pablo; Barreiro-Vázquez, José Daniel; Iglesias, Alfredo; Barreiro-Lois, Andrés

    2015-05-01

    Non-destructive techniques of core analysis, especially of marine cores, are being broadly employed for sedimentary, paleoceanographic and paleoclimate research. In particular, Computed Tomography scanning (CT-scanning) allows acquisition of 3D and 2D images, according to desired planes, and thus the identification of sedimentary structures, large grains and their distributions as well as direct measurements of material densities. The most significant contribution of this technique is the possibility of getting results before opening the core. In this work CT-scan data obtained for five cores from the Galicia Interior Basin (GIB, NW Peninsula Iberia) are presented and discussed, focussing on (1) methodology of the CT-scan use, (2) tomographic description of sedimentary facies identified in the GIB, (3) treatment of the numeric data obtained with CT-scanning using specific software (anidoC), and (4) comparison of tomographic data with data obtained by conventional methodologies of core analysis. The most singular feature of GIB cores is the presence of Ice Rafted Debris (IRD) deposited during late Pleistocene Heinrich Events (HE), which can be easily recognized using the CT-scan by the presence of high radio-density grains immersed in a low radio-density matrix. Comparison of CT-scan data with analytical sedimentary data and HE proxies performed on the cores validates the CT-scanning method as a powerful tool to improve correlations, identify well-constrained events, and make more accurate basin reconstructions without opening all the cores in an oceanographic study.

  5. The use of the eyes protection for dose reduction in CT scans of skull; O uso do protetor de olhos para reducao da dose varreduras de TC de cranio

    Energy Technology Data Exchange (ETDEWEB)

    Mourao, Arnaldo P. [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil); Silva, Teogenes A. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Alonso, Thessa C., E-mail: alonso@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2013-11-01

    The technique for imaging the brain scans of the skull by computed tomography (CT) scanning is the volume bounded by the foramen magnum and the apex of the skull. The lenses are radiosensitive tissues and CT scans of the head deposited significant doses on them, since they are in the region of incidence of the primary beam of X-rays. Thus, the variation of the dose deposited in the crystalline skull CT scans for diagnostic imaging of the brain was investigated. Cranial scans were performed using the acquisition protocol routine with or without the use of bismuth to shield the eyes. To carry out the scans we used a male anthropomorphic phantom, Alderson Rando model and dosimeters (TLD-100) were used to record the doses. These TLDs were used to record specific doses internally to the phantom in specific organs (crystalline, pituitary, thyroid, spinal cord and breasts). The scans were performed on a GE machine, model 64 Discovery channels. The data obtained allowed to observe the variation of dose in organs. The highest dose was recorded in the lens (26,18 mGy), followed by spinal cord (17,79 mGy). Comparing the doses of the two scans it was significant variation in the crystal. Scan using bismuth shield generated smaller doses in the eyes and in the eyes occurred the higher dose reduction, about 37%. The results may contribute to spread a suitable procedure for the optimization of CT scans of the skull.

  6. Scanning laser topography and scanning laser polarimetry: comparing both imaging methods at same distances from the optic nerve head.

    Science.gov (United States)

    Kremmer, Stephan; Keienburg, Marcus; Anastassiou, Gerasimos; Schallenberg, Maurice; Steuhl, Klaus-Peter; Selbach, J Michael

    2012-01-01

    To compare the performance of scanning laser topography (SLT) and scanning laser polarimetry (SLP) on the rim of the optic nerve head and its surrounding area and thereby to evaluate whether these imaging technologies are influenced by other factors beyond the thickness of the retinal nerve fiber layer (RNFL). A total of 154 eyes from 5 different groups were examined: young healthy subjects (YNorm), old healthy subjects (ONorm), patients with normal tension glaucoma (NTG), patients with open-angle glaucoma and early glaucomatous damage (OAGE) and patients with open-angle glaucoma and advanced glaucomatous damage (OAGA). SLT and SLP measurements were taken. Four concentric circles were superimposed on each of the images: the first one measuring at the rim of the optic nerve head (1.0 ONHD), the next measuring at 1.25 optic nerve head diameters (ONHD), at 1.5 ONHD and at 1.75 ONHD. The aligned images were analyzed using GDx/NFA software. Both methods showed peaks of RNFL thickness in the superior and inferior segments of the ONH. The maximum thickness, registered by the SLT device was at the ONH rim where the SLP device tended to measure the lowest values. SLT measurements at the ONH were influenced by other tissues besides the RNFL like blood vessels and glial tissues. SLT and SLP were most strongly correlated at distances of 1.25 and 1.5 ONHD. While both imaging technologies are valuable tools in detecting glaucoma, measurements at the ONH rim should be interpreted critically since both methods might provide misleading results. For the assessment of the retinal nerve fiber layer we would like to recommend for both imaging technologies, SLT and SLP, measurements in 1.25 and 1.5 ONHD distance of the rim of the optic nerve head.

  7. Patellar subluxation syndrome. Observation of the patellofemoral joint using CT-scan

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, Tomonori; Sasaki, Tetsuto; Susuda, Koichi; Moji, Junichi (Hokkaido Univ., Sapporo (Japan). School of Medicine)

    1983-10-01

    Clinical symptoms of patellar subluxation syndrome associated with pain were investigated for 24 knees of 20 patients, and the state of patella dislocation was observed by CT-scan. The patients had high incidence of an apprehension sign, showing their fear of patellar luxation. Many of them complained of patello-femoral joint pain due to chondromalacia patellae. In order to derive patellar subluxation, the method of CT-Q-contraction was carried out at the extended position of the patellar joint. In patients with patellar subluxation syndrome, the rate of shift in the diseased side was significantly higher than that of the other side, suggesting decreased muscular strength of the musculus vastus of the diseased side. Improvement of the symptoms was seen in all except one of 12 knees operated by the combined method of Green's method with Blauth's more than 6 months before. Availability of this operation was verified by the CT-Q-contraction.

  8. Hawk eyes II: diurnal raptors differ in head movement strategies when scanning from perches.

    Directory of Open Access Journals (Sweden)

    Colleen T O'Rourke

    Full Text Available BACKGROUND: Relatively little is known about the degree of inter-specific variability in visual scanning strategies in species with laterally placed eyes (e.g., birds. This is relevant because many species detect prey while perching; therefore, head movement behavior may be an indicator of prey detection rate, a central parameter in foraging models. We studied head movement strategies in three diurnal raptors belonging to the Accipitridae and Falconidae families. METHODOLOGY/PRINCIPAL FINDINGS: We used behavioral recording of individuals under field and captive conditions to calculate the rate of two types of head movements and the interval between consecutive head movements. Cooper's Hawks had the highest rate of regular head movements, which can facilitate tracking prey items in the visually cluttered environment they inhabit (e.g., forested habitats. On the other hand, Red-tailed Hawks showed long intervals between consecutive head movements, which is consistent with prey searching in less visually obstructed environments (e.g., open habitats and with detecting prey movement from a distance with their central foveae. Finally, American Kestrels have the highest rates of translational head movements (vertical or frontal displacements of the head keeping the bill in the same direction, which have been associated with depth perception through motion parallax. Higher translational head movement rates may be a strategy to compensate for the reduced degree of eye movement of this species. CONCLUSIONS: Cooper's Hawks, Red-tailed Hawks, and American Kestrels use both regular and translational head movements, but to different extents. We conclude that these diurnal raptors have species-specific strategies to gather visual information while perching. These strategies may optimize prey search and detection with different visual systems in habitat types with different degrees of visual obstruction.

  9. A computational framework for cancer response assessment based on oncological PET-CT scans.

    Science.gov (United States)

    Sampedro, Frederic; Escalera, Sergio; Domenech, Anna; Carrio, Ignasi

    2014-12-01

    In this work we present a comprehensive computational framework to help in the clinical assessment of cancer response from a pair of time consecutive oncological PET-CT scans. In this scenario, the design and implementation of a supervised machine learning system to predict and quantify cancer progression or response conditions by introducing a novel feature set that models the underlying clinical context is described. Performance results in 100 clinical cases (corresponding to 200 whole body PET-CT scans) in comparing expert-based visual analysis and classifier decision making show up to 70% accuracy within a completely automatic pipeline and 90% accuracy when providing the system with expert-guided PET tumor segmentation masks. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. The prognostic value of brain CT scan in infants with periventricular leukomalacia

    Energy Technology Data Exchange (ETDEWEB)

    Okumura, Akihisa; Hayakawa, Fumio; Kuno, Kuniyoshi (Anjo Kosei Hospital, Aichi (Japan)); Natsume, Jun; Watanabe, Kazuyoshi

    1994-11-01

    Brain CT scan was performed at 40 weeks of conceptional age in 17 preterm infants with periventricular leukomalacia (PVL). The finding of periventricular low density was not useful in differentiating patients with PVL from normal infants, because this finding was seen in 40% of normal infants. The following findings were characteristic of PVL : (1) a marked low density area in centrum semioval, (2) an irregular outline of ventricular wall, and (3) low density spots in periventricular white matter. The findings of ventricular dilation with irregular wall and marked low density area in centrum semioval were correlated with a finding of volume loss on MRI during late infancy and the severity of neurological impairment, especially in severely affected patients. Marked low density area in centrum semioval was characteristic of severe PVL as demonstrated on brain CT scan. (author).

  11. Semiautomatic methods for segmentation of the proliferative tumour volume on sequential FLT PET/CT images in head and neck carcinomas and their relation to clinical outcome

    Energy Technology Data Exchange (ETDEWEB)

    Arens, Anne I.J.; Grootjans, Willem; Oyen, Wim J.G.; Visser, Eric P. [Radboud University Medical Center, Department of Nuclear Medicine, P.O. Box 9101, Nijmegen (Netherlands); Troost, Esther G.C. [Radboud University Medical Center, Department of Radiation Oncology, Nijmegen (Netherlands); Maastricht University Medical Centre, MAASTRO clinic, GROW School for Oncology and Developmental Biology, Maastricht (Netherlands); Hoeben, Bianca A.W.; Bussink, Johan; Kaanders, Johannes H.A.M. [Radboud University Medical Center, Department of Radiation Oncology, Nijmegen (Netherlands); Lee, John A.; Gregoire, Vincent [St-Luc University Hospital, Department of Radiation Oncology, Universite Catholique de Louvain, Brussels (Belgium); Hatt, Mathieu; Visvikis, Dimitris [Laboratoire de Traitement de l' Information Medicale (LaTIM), INSERM UMR1101, Brest (France)

    2014-05-15

    Radiotherapy of head and neck cancer induces changes in tumour cell proliferation during treatment, which can be depicted by the PET tracer {sup 18}F-fluorothymidine (FLT). In this study, three advanced semiautomatic PET segmentation methods for delineation of the proliferative tumour volume (PV) before and during (chemo)radiotherapy were compared and related to clinical outcome. The study group comprised 46 patients with 48 squamous cell carcinomas of the head and neck, treated with accelerated (chemo)radiotherapy, who underwent FLT PET/CT prior to treatment and in the 2nd and 4th week of therapy. Primary gross tumour volumes were visually delineated on CT images (GTV{sub CT}). PVs were visually determined on all PET scans (PV{sub VIS}). The following semiautomatic segmentation methods were applied to sequential PET scans: background-subtracted relative-threshold level (PV{sub RTL}), a gradient-based method using the watershed transform algorithm and hierarchical clustering analysis (PV{sub W} and {sub C}), and a fuzzy locally adaptive Bayesian algorithm (PV{sub FLAB}). Pretreatment PV{sub VIS} correlated best with PV{sub FLAB} and GTV{sub CT}. Correlations with PV{sub RTL} and PV{sub W} and {sub C} were weaker although statistically significant. During treatment, the PV{sub VIS}, PV{sub W} and {sub C} and PV{sub FLAB} significant decreased over time with the steepest decline over time for PV{sub FLAB}. Among these advanced segmentation methods, PV{sub FLAB} was the most robust in segmenting volumes in the third scan (67 % of tumours as compared to 40 % for PV{sub W} and {sub C} and 27 % for PV{sub RTL}). A decrease in PV{sub FLAB} above the median between the pretreatment scan and the scan obtained in the 4th week was associated with better disease-free survival (4 years 90 % versus 53 %). In patients with head and neck cancer, FLAB proved to be the best performing method for segmentation of the PV on repeat FLT PET/CT scans during (chemo)radiotherapy. This may

  12. Cystic Fibrosis: Are Volumetric Ultra-Low-Dose Expiratory CT Scans Sufficient for Monitoring Related Lung Disease?

    DEFF Research Database (Denmark)

    Loeve, Martine; Lequin, Maarten H; Bruijne, Marleen de

    2009-01-01

    that differences in scores were independent of score magnitude. Conclusion: In this pilot study, CT scores from end-expiratory and end-inspiratory CT match closely, suggesting that ultra-low-dose end-expiratory CT alone may be sufficient for monitoring CF-related lung disease. This would help reduce radiation dose......Purpose: To assess whether chest computed tomography (CT) scores from ultra-low-dose end-expiratory scans alone could suffice for assessment of all cystic fibrosis (CF)-related structural lung abnormalities. Materials and Methods: In this institutional review board–approved study, 20 patients...... with CF aged 6–20 years (eight males, 12 females) underwent low-dose end-inspiratory CT and ultra-low-dose end-expiratory CT. Informed consent was obtained. Scans were randomized and scored by using the Brody-II CT scoring system to assess bronchiectasis, airway wall thickening, mucus plugging...

  13. Automatic segmentation and quantification of the cardiac structures from non-contrast-enhanced cardiac CT scans

    Science.gov (United States)

    Shahzad, Rahil; Bos, Daniel; Budde, Ricardo P. J.; Pellikaan, Karlijn; Niessen, Wiro J.; van der Lugt, Aad; van Walsum, Theo

    2017-05-01

    Early structural changes to the heart, including the chambers and the coronary arteries, provide important information on pre-clinical heart disease like cardiac failure. Currently, contrast-enhanced cardiac computed tomography angiography (CCTA) is the preferred modality for the visualization of the cardiac chambers and the coronaries. In clinical practice not every patient undergoes a CCTA scan; many patients receive only a non-contrast-enhanced calcium scoring CT scan (CTCS), which has less radiation dose and does not require the administration of contrast agent. Quantifying cardiac structures in such images is challenging, as they lack the contrast present in CCTA scans. Such quantification would however be relevant, as it enables population based studies with only a CTCS scan. The purpose of this work is therefore to investigate the feasibility of automatic segmentation and quantification of cardiac structures viz whole heart, left atrium, left ventricle, right atrium, right ventricle and aortic root from CTCS scans. A fully automatic multi-atlas-based segmentation approach is used to segment the cardiac structures. Results show that the segmentation overlap between the automatic method and that of the reference standard have a Dice similarity coefficient of 0.91 on average for the cardiac chambers. The mean surface-to-surface distance error over all the cardiac structures is 1.4+/- 1.7 mm. The automatically obtained cardiac chamber volumes using the CTCS scans have an excellent correlation when compared to the volumes in corresponding CCTA scans, a Pearson correlation coefficient (R) of 0.95 is obtained. Our fully automatic method enables large-scale assessment of cardiac structures on non-contrast-enhanced CT scans.

  14. Atlantoaxial Ankylosis Detected on Neck CT Scans in a Patient with Ankylosing Spondylitis: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Ah; Lee, Seung Hun; Joo, Kyung Bin [Dept. of Radiology, Seoul Hospital, Hanyang University College of Medicine, Seoul (Korea, Republic of); Ryu, Jeong Ah [Dept. of Radiology, Guri Hospital, Hanyang University College of Medicine, Guri (Korea, Republic of); Kim, Tae Hwan [Dept. of Rheynmatology, Seoul Hospital, Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2011-07-15

    Ankylosing spondylitis is a chronic inflammatory disorder of unknown cause that principally affects the axial skeleton. The cervical spine is also vulnerable to this disease process and the characteristic feature of cervical involvement is atlantoaxial subluxation. However, only a few cases of atlantoaxial ankylosis have been reported to date. We report a case of atlantoaxial ankylosis in a patient with ankylosing spondylitis with radiologic findings incidentally detected on neck CT scans.

  15. Renal Tumor Cryoablation Planning. The Efficiency of Simulation on Reconstructed 3D CT Scan

    Directory of Open Access Journals (Sweden)

    Ciprian Valerian LUCAN

    2010-12-01

    Full Text Available Introduction & Objective: Nephron-sparing surgical techniques risks are related to tumor relationships with adjacent anatomic structures. Complexity of the renal anatomy drives the interest to develop tools for 3D reconstruction and surgery simulation. The aim of the article was to assess the simulation on reconstructed 3D CT scan used for planning the cryoablation. Material & Method: A prospective randomized study was performed between Jan. 2007 and July 2009 on 27 patients who underwent retroperitoneoscopic T1a renal tumors cryoablation (RC. All patients were assessed preoperatively by CT scan, also used for 3D volume rendering. In the Gr.A, the patients underwent surgery planning by simulation on 3D CT scan. In the Gr.B., patients underwent standard RC. The two groups were compared in terms of surgical time, bleeding, postoperative drainage, analgesics requirement, hospital stay, time to socio-professional reintegration. Results: Fourteen patients underwent preoperative cryoablation planning (Gr.A and 13 patients underwent standard CR (Gr.B. All parameters analyzed were shorter in the Gr.A. On multivariate logistic regression, only shortens of the surgical time (138.79±5.51 min. in Gr.A. vs. 140.92±5.54 min in Gr.B. and bleeding (164.29±60.22 mL in Gr.A. vs. 215.38±100.80 mL in Gr.B. achieved statistical significance (p<0.05. The number of cryoneedles assessed by simulation had a 92.52% accuracy when compared with those effectively used. Conclusions: Simulation of the cryoablation using reconstructed 3D CT scan improves the surgical results. The application used for simulation was able to accurately assess the number of cryoneedles required for tumor ablation, their direction and approach.

  16. Intraventricular tuberculoma. Report of four cases in children. [CT scan findings described

    Energy Technology Data Exchange (ETDEWEB)

    Berthier, M.; Sierra, J.; Leiguarda, R.

    1987-03-01

    Four cases of intraventricular tuberculoma (IVT) in children are here reported. In none of the patients was there clinical evidence pointing to the intraventricular location. CT scan findings comprised three stages of development, namely: immature, mature and old. Ependymal attachment and asymmetric hydrocephalus were present in three cases, meningitis in two and ependymitis in one. Septum pellucidum traction was clearly observed in two patients, strongly supporting an adhesive process characteristic of intraventricular tuberculosis. Following specific treatment, the tuberculomas remitted partially or entirely.

  17. Lumbar spine joint synovial cysts of intraspinal development. CT scan imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vallee, C.; Chevrot, A.; Benhamouda, M. and others

    CT scan imaging findings are described in 22 patients with lumbar spine joint synovial cysts, of intraspinal development, provoking sciatica or lumbosciatica from nerve compression in spinal canal. Diagnosis was suggested by a mass at the posterior joint level, of variable density, sometimes with peripheral calcification, presenting a vacuum appearance on occasions, and with enhanced image with contrast. Differential diagnosis is from excluded hernia and postoperative fibrosis. Posterior intra-articular arthrography can confirm diagnosis and allow treatment with prolonged action corticoid infiltrations.

  18. Anatomical basis for the interpretation of CT-scan imaging of the lumbar spine. Pitfalls

    Energy Technology Data Exchange (ETDEWEB)

    Laredo, J.D.; Bard, M.

    1988-01-01

    A good understanding of the normal anatomy of the lumbar spine is required for the interpretation of CT-scans obtained for ischiatic or crural neuralgia. An attempt has been made to rely on precise terminology to designate each anatomical region pertaining to the lumbar canal. Examples of tomodensitometric investigations of the normal intervertebral space are given, and criteria allowing for the identification of normal anatomical variations are also provided.

  19. Thoracic CT

    Science.gov (United States)

    ... lungs; CT scan - chest Images CT scan Thyroid cancer - CT scan Pulmonary nodule, solitary - CT scan Lung mass, right upper ... Chest Injuries and Disorders CT Scans Emphysema Lung Cancer Lung Diseases Pleural Disorders Pneumonia Pulmonary Embolism Tuberculosis Browse the Encyclopedia A.D.A. ...

  20. Prevalence of incidental findings in paranasal sinus in brain and orbital CT scans in pediatric patients

    Directory of Open Access Journals (Sweden)

    Adriano Ferreira da Silva

    2011-09-01

    Full Text Available In emergency services a significant amount of pediatric patients undergoa brain or orbit CT scans for suspicion other than sinusitis. Assuming thispremise, this study was held to show the incidental findings of the paranasalsinuses of children with nonspecific symptoms such as fever, headache andvomiting that underwent brain or orbits CT scans, without the initial suspicion of sinusitis. In a retrospective study, we evaluated 70 CT scans of the brainand orbits of children between 0 and 12 years. The incidental findings of theparanasal sinuses occurred in 32 cases (45.7%. Mucosal thickening was themost common incidental finding, being observed in 35% of patients, followed bycomplete opacification observed in 28% of cases and incomplete opacificationobserved in 28% of patients. Bilateral involvement occurred in 78% patients.The sinuses most frequently affected were the maxillary sinus followed byethmoid sinuses. The abnormalities were more severe in children under theage of three years. The prevalence of incidental tomographic abnormalities inpatients without an initial diagnosis of sinusitis is high. The predominance ofthese findings are mild abnormalities.

  1. Case of primary pontine hemorrhage of the young adult followed by CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Mashiyama, Shoji; Higuchi, Hiroshi; Takahashi, Akira

    1985-01-01

    A case of primary pontine hemorrhage of the young was reported. He was 22 years of age, who did not have the history of hypertension. He suddenly noticed disturbance of skilled act of his right hand and speech disturbance. He was admitted to our clinic two days after the onset. Neurological examination revealed right facial palsy, disturbance of delicate movement of his right hand and slight dysarthria. Lumbar puncture, after six days from the onset, yielded watery clear cerebrospinal fluid containing 6/3 cells/mm/sup 3/, 27mg/dl of protein and 65.1 mg/dl of sugar. An opening pressure was 75 mmH/sub 2/O. The vertebral angiography revealed no evidence of mass lesion and vascular anomalies. CT scan demonstrated a pontine hematoma, the size of this hematoma sequentially enlarged in follow-up CT scan. His clinical symptoms were gradually aggravated, i.e. cerebellar sign, urinary disturbance and involuntary movement. Conservative therapy was performed and his symptoms gradually improved. The size of hematoma was reduced in follow-up CT scan. The genesis, diagnosis and treatment of primary pontine hemorrhage of the young were discussed. (author).

  2. Differentiation between eclampsia and cerebrovascular disorders by brain CT scan in pregnant patients with convulsive seizures

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, Katsuto; Lin, Yaw-Tyng; Noda, Kiyofumi; Saeki, Kazuhiko; Yonezawa, Masaru; Sekiba, Kaoru; Ochiai, Youji

    1987-06-01

    Six pregnant women with convulsions between 25 to 40 weeks of gestation were experienced. Among them, 4 patients were diagnosed as having intracranial hemorrhage and two as simple eclampsia. With the aid of brain CT scan, one case of arteriovenous malformation was detected and treated surgically with good prognosis for both the mother and the fetus. Two patients were diagnosed to have cerebral hemorrhage with subsequent penetration into the lateral ventricles and were treated conservatively. Their fetuses were delivered alive by cesarean section, but the mothers expired. The other patient with cerebral hemorrhage was treated surgically, and both the mother and the fetus survived. One of the simple eclampsia patients was noted to have a growth retarded fetus at 32 weeks of pregnancy with subsequent intra-uterine death, but the mother recovered after conservative treatment. Another patient at 40 weeks of pregnancy was also treated conservatively and both the fetus and the mother survived. Brain CT scan findings differed between these two eclampsia patients; local brain edema for the second patient and generalized brain edema for the first patient. Thus more active application of brain CT scan is recommended in managing pregnant patients with convulsions.

  3. 3D segmentation of abdominal aorta from CT-scan and MR images.

    Science.gov (United States)

    Duquette, Anthony Adam; Jodoin, Pierre-Marc; Bouchot, Olivier; Lalande, Alain

    2012-06-01

    We designed a generic method for segmenting the aneurismal sac of an abdominal aortic aneurysm (AAA) both from multi-slice MR and CT-scan examinations. It is a semi-automatic method requiring little human intervention and based on graph cut theory to segment the lumen interface and the aortic wall of AAAs. Our segmentation method works independently on MRI and CT-scan volumes and has been tested on a 44 patient dataset and 10 synthetic images. Segmentation and maximum diameter estimation were compared to manual tracing from 4 experts. An inter-observer study was performed in order to measure the variability range of a human observer. Based on three metrics (the maximum aortic diameter, the volume overlap and the Hausdorff distance) the variability of the results obtained by our method is shown to be similar to that of a human operator, both for the lumen interface and the aortic wall. As will be shown, the average distance obtained with our method is less than one standard deviation away from each expert, both for healthy subjects and for patients with AAA. Our semi-automatic method provides reliable contours of the abdominal aorta from CT-scan or MRI, allowing rapid and reproducible evaluations of AAA.

  4. Spinal uptake mimicking metastasis in SPECT/CT bone scan in a patient with superior vena cava obstruction.

    Science.gov (United States)

    Rager, Olivier; Nkoulou, René; Garibotto, Valentina; Boudabbous, Sana; Arditi, Daniel

    2013-11-01

    A 46-year-old female patient with a mediastinal neuroendocrine carcinoma complicated by superior vena cava syndrome was referred for a bone metastatic workup. Bone scan with SPECT/CT showed several vertebral fixations without alterations on the unenhanced CT, but a CT scan with injection of contrast media showed vertebral densities matched to the lesions described on the SPECT/CT. This pattern confirmed presence of collateral paths through vertebral veins due to superior vena cava syndrome. Lack of metastases was confirmed by MRI.

  5. FDG-PET/contrast-enhanced CT as a post-treatment tool in head and neck squamous cell carcinoma: comparison with FDG-PET/non-contrast-enhanced CT and contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Suenaga, Yuko; Kitajima, Kazuhiro; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Ishihara, Takeaki; Sasaki, Ryohei [Kobe University Graduate, School of Medicine, Department of Radiology, Division of Radiation Oncology, Kobe (Japan); Otsuki, Naoki; Nibu, Ken-ichi [Kobe University Graduate, School of Medicine, Department of Otolaryngology-Head and Neck Surgery, Kobe (Japan); Minamikawa, Tsutomu [Kobe University Graduate School of Medicine, Department of Oral and Maxillofacial Surgery, Kobe (Japan); Kiyota, Naomi [Kobe University Hospital, Department of Medical Oncology and Hematology, Kobe (Japan)

    2016-04-15

    To evaluate the accuracy of PET/CT using {sup 18}F-fluorodeoxyglucose (FDG) with IV contrast for suspected recurrent head and neck squamous cell carcinoma (HNSCC). One hundred and seventy patients previously treated for HNSCC underwent PET/CT, consisting of non-contrast-enhanced and contrast-enhanced CT, to investigate suspected recurrence. Diagnostic performance of PET/contrast-enhanced CT (PET/ceCT), PET/non-contrast-enhanced CT (PET/ncCT) and contrast-enhanced CT (ceCT) for local or regional recurrence, distant metastasis, overall recurrence and second primary cancer was evaluated. The reference standard included histopathology, treatment change and imaging follow-up. The patient-based areas under the receiver operating characteristic curves (AUC) for ceCT, PET/ncCT and PET/ceCT were 0.82, 0.96 and 0.98 for local recurrence, 0.73, 0.86 and 0.86 for regional recurrence, 0.86, 0.91 and 0.92 for distant metastasis, 0.72, 0.86 and 0.87 for overall recurrence, and 0.86, 0.89 and 0.91 for a second primary cancer. Both PET/ceCT and PET/ncCT statistically showed larger AUC than ceCT for recurrence, and the difference between PET/ceCT and PET/ncCT for local recurrence reached a significant level (p = 0.039). The accuracy of PET/ceCT for diagnosing overall recurrence was high, irrespective of the time interval after the last treatment (83.3-94.1 %). FDG-PET/CT was a more accurate HNSCC restaging tool than ceCT. The added value of ceCT at FDG-PET/CT is minimal. (orig.)

  6. TIPS bilateral noise reduction in 4D CT perfusion scans produces high-quality cerebral blood flow maps

    NARCIS (Netherlands)

    Mendrik, A.M.; Vonken, E.J.; Ginneken, B. van; Jong, H.W. de; Riordan, A.; Seeters, T. van; Smit, E.J.; Viergever, M.A.; Prokop, M.

    2011-01-01

    Cerebral computed tomography perfusion (CTP) scans are acquired to detect areas of abnormal perfusion in patients with cerebrovascular diseases. These 4D CTP scans consist of multiple sequential 3D CT scans over time. Therefore, to reduce radiation exposure to the patient, the amount of x-ray radiat

  7. TIPS bilateral noise reduction in 4D CT perfusion scans produces high-quality cerebral blood flow maps

    NARCIS (Netherlands)

    A. Mendrik (Adrienne); E.J.P.A. Vonken; B.T.J. van Ginneken (Berbke); J.R. Riordan (John ); H.W.A.M. de Jong (Hugo); T. van Seeters (Tom); E.J. Smit (Ewoud); M.A. Viergever (Max); M. Prokop (Mathias)

    2011-01-01

    textabstractCerebral computed tomography perfusion (CTP) scans are acquired to detect areas of abnormal perfusion in patients with cerebrovascular diseases. These 4D CTP scans consist of multiple sequential 3D CT scans over time. Therefore, to reduce radiation exposure to the patient, the amount of

  8. Multidetector row computed tomography of acute pancreatitis: Utility of single portal phase CT scan in short-term follow up

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Yongwonn [Department of Radiology, Konkuk University Medical Center, 4-12, Hwayang-dong, Gwangjin-gu, Seoul 143-729 (Korea, Republic of); Park, Hee Sun, E-mail: heesun.park@gmail.com [Department of Radiology, Konkuk University Medical Center, 4-12, Hwayang-dong, Gwangjin-gu, Seoul 143-729 (Korea, Republic of); Kim, Young Jun; Jung, Sung Il; Jeon, Hae Jeong [Department of Radiology, Konkuk University Medical Center, 4-12, Hwayang-dong, Gwangjin-gu, Seoul 143-729 (Korea, Republic of)

    2012-08-15

    Objective: The purpose of this study is to evaluate the question of whether nonenhanced CT or contrast enhanced portal phase CT can replace multiphasic pancreas protocol CT in short term monitoring in patients with acute pancreatitis. Materials and methods: This retrospective study was approved by the Institutional Review Board. From April 2006 to May 2010, a total of 52 patients having acute pancreatitis who underwent initial dual phase multidetector row CT (unenhanced, arterial, and portal phase) at admission and a short term (within 30 days) follow up dual phase CT (mean interval 10.3 days, range 3-28 days) were included. Two abdominal radiologists performed an independent review of three sets of follow up CT images (nonenhanced scan, single portal phase scan, and dual phase scan). Interpretation of each image set was done with at least 2-week interval. Radiologists evaluated severity of acute pancreatitis with regard to pancreatic inflammation, pancreatic necrosis, and extrapancreatic complication, based on the modified CT severity index. Scores of each image set were compared using a paired t-test and interobserver agreement was evaluated using intraclass correlation coefficient statistics. Results: Mean scores of sum of CT severity index on nonenhanced scan, portal phase scan, and dual phase scan were 5.7, 6.6, and 6.5 for radiologist 1, and 5.0, 5.6, and 5.8 for radiologist 2, respectively. In both radiologists, contrast enhanced scan (portal phase scan and dual phase scan) showed significantly higher severity score compared with that of unenhanced scan (P < 0.05), while portal phase and dual phase scan showed no significant difference each other. The trend was similar regarding pancreatic inflammation and extrapancreatic complications, in which contrast enhanced scans showed significantly higher score compared with those of unenhanced scan, while no significant difference was observed between portal phase scan and dual phase scan. In pancreatic necrosis

  9. Repeat CT-scan assessment of lymph node motion in locally advanced cervical cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Bondar, Luiza; Velema, Laura; Mens, Jan Willem; Heijmen, Ben; Hoogeman, Mischa [Erasmus Medical Center Cancer Institute, Department of Radiation Oncology, 3008 AE, Rotterdam (Netherlands); Zwijnenburg, Ellen [Radboud University Medical Center, Department of Radiation Oncology, Nijmegen (Netherlands)

    2014-12-15

    In cervical cancer patients the nodal clinical target volume (CTV, defined using the major pelvic blood vessels and enlarged lymph nodes) is assumed to move synchronously with the bony anatomy. The aim of this study was to verify this assumption by investigating the motion of the major pelvic blood vessels and enlarged lymph nodes visible in CT scans. For 13 patients treated in prone position, four variable bladder-filling CT scans per patient, acquired at planning and after 40 Gy, were selected from an available dataset of 9-10 CT scans. The bladder, rectum, and the nodal-vessels structure containing the iliac vessels and all visible enlarged nodes were delineated in each selected CT scan. Two online patient setup correction protocols were simulated. The first corrected bony anatomy translations and the second corrected translations and rotations. The efficacy of each correction was calculated as the overlap between the nodal-vessels structure in the reference and repeat CT scans. The motion magnitude between delineated structures was quantified using nonrigid registration. Translational corrections resulted in an average overlap of 58 ± 13% and in a range of motion between 9.9 and 27.3 mm. Translational and rotational corrections significantly improved the overlap (64 ± 13%, p value = 0.007) and moderately reduced the range of motion to 7.6-23.8 mm (p value = 0.03). Bladder filling changes significantly correlated with the nodal-vessels motion (p < 0.001). The motion of the nodal-vessels was large, nonrigid, patient-specific, and only moderately synchronous with the bony anatomy. This study highlights the need for caution when reducing the CTV-to-PTV (PTV planning target volume) margin of the nodal CTV for highly conformal radiation techniques. (orig.) [German] Bei Zervixkarzinompatientinnen wird davon ausgegangen, dass das nodale klinische Zielvolumen (CTV, definiert anhand der grossen Blutgefaesse des Beckens und vergroesserter Lymphknoten) sich synchron mit

  10. Planned FDG PET-CT Scan in Follow-Up Detects Disease Progression in Patients With Locally Advanced NSCLC Receiving Curative Chemoradiotherapy Earlier Than Standard CT

    DEFF Research Database (Denmark)

    Pan, Yi; Brink, Carsten; Schytte, Tine;

    2015-01-01

    The role of positron emission tomography-computed tomography (PET-CT) in surveillance of patients with nonsmall cell lung cancer (NSCLC) treated with curatively intended chemoradiotherapy remains controversial. However, conventional chest X-ray and computed tomography (CT) are of limited value...... in discriminating postradiotherapy changes from tumor relapse. The aim of this study was to evaluate the clinical value of PET-CT scan in the follow-up for patients with locally advanced (LA) NSCLC receiving concomitant chemoradiotherapy (CCRT).Between 2009 and 2013, eligible patients with stages IIB-IIIB NSCLC...... were enrolled in the clinical trial NARLAL and treated in Odense University Hospital (OUH). All patients had a PET-CT scan scheduled 9 months (PET-CT9) after the start of the radiation treatment in addition to standard follow-up (group A). Patients who presented with same clinical stage of NSCLC...

  11. Value of MR and CT Imaging for Assessment of Internal Carotid Artery Encasement in Head and Neck Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    W. L. Lodder

    2013-01-01

    Full Text Available Objective. This study was conducted to assess the value of CT and MR imaging in the preoperative evaluation of ICA encasement. Methods. Based upon three patient groups this study was performed. Retrospective analysis of 260 neck dissection reports from 2001 to 2010 was performed to determine unexpected peroperative-diagnosed encasement. Two experienced head and neck radiologists reviewed 12 scans for encasement. Results. In four out of 260 (1.5% patients undergoing neck dissection, preoperative imaging was false negative as there was peroperative encasement of the ICA. Of 380 patients undergoing preoperative imaging, the radiologist reported encasement of the ICA in 25 cases. In 342 cases no encasement was described, 125 of these underwent neck dissection, and 2 had encasement peroperatively. The interobserver variation kappa varied from 0.273 to 1 for the different characteristics studied. Conclusion. These retrospectively studied cohorts demonstrate that preoperative assessment of encasement of the ICA using MRI and/or CT was of value in evaluation of ICA encasement and therefore contributively in selecting operable patients (without ICA encasement, since in only 1.5% encasement was missed. However, observer variation affects the reliability of this feature.

  12. Prognostic value of FDG PET/CT in head and neck squamous cell carcinomas

    Directory of Open Access Journals (Sweden)

    Dequanter D

    2015-08-01

    Full Text Available D Dequanter,1,2 M Shahla,2 C Aubert,2 Y Deniz,2 P Lothaire2 1Department of Oncology, Laboratory of Experimental Radiotherapy, KU Leuven, Leuven, Belgium; 2Head and Neck Department, Hôpital André Vésale, CHU de Charleroi, Montigny le Tilleul, Belgium Introduction: The purpose of this study was to evaluate the use of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT to identify the presence of cervical lymph nodes metastases and extracapsular spread with histologic correlations in head and neck squamous cell carcinoma.Methods: The medical records of 54 patients who underwent 18F-FDG PET/CT for head and neck squamous cell carcinoma before surgery were reviewed. Receiver operating characteristic (ROC analysis was performed to differentiate patients with cervical lymph node metastasis from those without lymph node metastasis. The same statistical analysis was done to differentiate cervical lymph nodes with extracapsular spread from those without extracapsular spread.Results: Metastatic disease was diagnosed histologically in 49% (26 of 54 of the patients. Extracapsular spread was present in ten of the 54 patients (19%. When ROC curve analysis and maximum standardized uptake (SUVmax values were used to detect cervical lymph node metastasis, the area under the ROC curve was 0.96 and the optimal cutoff value for SUVmax was 4.05 based on ROC curve analysis. The sensitivity and specificity of SUVmax for the detection of cervical lymph node metastasis using this cutoff point were 92% and 88%, respectively. When ROC curve analysis and SUVmax values were used in order to detect extracapsular spread, the area under the ROC curve was 0.86, and the optimal cutoff value for SUVmax was 4.15 based on ROC curve analysis. Using this cutoff value, the sensitivity and specificity of SUVmax for the detection of extracapsular spread were 83% and 88%, respectively.Conclusion: In our study, a median 18F-FDG PET/CT SUVmax cutoff

  13. A measurement-based generalized source model for Monte Carlo dose simulations of CT scans

    Science.gov (United States)

    Ming, Xin; Feng, Yuanming; Liu, Ransheng; Yang, Chengwen; Zhou, Li; Zhai, Hezheng; Deng, Jun

    2017-03-01

    The goal of this study is to develop a generalized source model for accurate Monte Carlo dose simulations of CT scans based solely on the measurement data without a priori knowledge of scanner specifications. The proposed generalized source model consists of an extended circular source located at x-ray target level with its energy spectrum, source distribution and fluence distribution derived from a set of measurement data conveniently available in the clinic. Specifically, the central axis percent depth dose (PDD) curves measured in water and the cone output factors measured in air were used to derive the energy spectrum and the source distribution respectively with a Levenberg–Marquardt algorithm. The in-air film measurement of fan-beam dose profiles at fixed gantry was back-projected to generate the fluence distribution of the source model. A benchmarked Monte Carlo user code was used to simulate the dose distributions in water with the developed source model as beam input. The feasibility and accuracy of the proposed source model was tested on a GE LightSpeed and a Philips Brilliance Big Bore multi-detector CT (MDCT) scanners available in our clinic. In general, the Monte Carlo simulations of the PDDs in water and dose profiles along lateral and longitudinal directions agreed with the measurements within 4%/1 mm for both CT scanners. The absolute dose comparison using two CTDI phantoms (16 cm and 32 cm in diameters) indicated a better than 5% agreement between the Monte Carlo-simulated and the ion chamber-measured doses at a variety of locations for the two scanners. Overall, this study demonstrated that a generalized source model can be constructed based only on a set of measurement data and used for accurate Monte Carlo dose simulations of patients’ CT scans, which would facilitate patient-specific CT organ dose estimation and cancer risk management in the diagnostic and therapeutic radiology.

  14. Computer-assisted solid lung nodule 3D volumetry on CT : influence of scan mode and iterative reconstruction: a CT phantom study

    NARCIS (Netherlands)

    Coenen, Adriaan; Honda, Osamu; van der Jagt, Eric J.; Tomiyama, Noriyuki

    2013-01-01

    To evaluate the effect of high-resolution scan mode and iterative reconstruction on lung nodule 3D volumetry. Solid nodules with various sizes (5, 8, 10 and 12 mm) were placed inside a chest phantom. CT images were obtained with various tube currents, scan modes (conventional mode, high-resolution m

  15. CT SCAN FINDINGS IN PATIENTS WITH SEIZURES IN NOTHERN CHHATTISGARH : A RETROSPECTIVE STUDY

    Directory of Open Access Journals (Sweden)

    Archana

    2015-09-01

    Full Text Available A five years study of CT scan findings in seizure patients is carried out to know the different etiology. Seizure is a finite event of altered cerebral function because of excessive and abnormal electrical discharges of the brain cells. Epilepsy is a chronic condition predisposing a person to recurrent seizures. This study is designed to establish usefulness of CT in defining the etiology of seizures in various age groups in people of Northern Chhattisgarh. This is a retrospective hospital - based study conducted in Radio - diagnosis Department of Chhattisgarh Institute of Medical Sciences, Bilaspur, Chhattisgarh. The study was carried out over a 5 year period. Hospital admissions with history of seizures are very common. Almost 3 - 9% p er 1000 population of total hospital emergencies is seizure cases. Epilepsy is an important health problem in developing countries, where its prevalence can be up to 57 per 1000 population. This study has high prevalence of seizures in First, second, third and fourth decades with decreasing pattern with increasing age. Prevalence in first decade is low as compare to second and third decades. Tuberculoma (9.39% and Neurocysticercosis (3.60% has highest prevalence in partial seizures followed by Focal Cereb ral Edema (6.22% whereas Diffuse Cerebral edema (4.91% seen with Generalised Seizures Cerebral infarct has equally seen in both types of seizures. Brain tumour presented mostly with Generalised seizure (2.07% than in partial seizures (0.98% . Other abno rmal findings like Cerebral calcifications, Diffuse cortical atrophy, Focal cortical atrophy, Sub Arachnoid hemorrhage, Intracerebral Hemorrhage, Hypoxic Ischemic Encephalopathy, Hydrocephalus and few rare diseases like Fahr disease and Tuberous sclerosis have also seen in CT scan in seizure patients. CT scan is valuable in making a diagnosis particularly in Indian subcontinent, where infective causes in form of space occupying lesions and infections are most

  16. [The Difference of CT Value Related to Monitor Position in the Head CT-angiography Bolus Tracking Method for Patients with Subarachnoid Hemorrhage].

    Science.gov (United States)

    Mizui, Masato; Mizoguchi, Yuji; Tashiro, Takao

    2016-01-01

    The head computed tomography-angiography (head CT-A) examination is excellent for the detection and diagnosis of cerebral artery aneurysm. If we use bolus tracking method when implementing this examination, we must choose a monitoring point. We investigated the influence which the monitoring point (MCA or carotid-A) exerts on the CT value. As for the result, MCA monitoring point method was more excellent than the carotid artery monitoring point method. The CT value was higher about 50 HU in the MCA monitoring point than in the carotid artery monitoring point (average;carotid artery: 349.6±57.8 HU, MCA: 413.2±67.9 HU). So, we conclude that in the bolus tracking method of monitoring point of head CTA, MCA monitoring point should be used.

  17. Enhancement characteristics of the hepatic parenchyma in CT scanning during splenoportography

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiu-yi; ZHANG Xue-lin; ZHENG Wei-quan; WANG Jin; WEN Ge

    2002-01-01

    Objective: To evaluate the enhancement characteristics of the hepatic parenchyma during scanning with computed tomography (CT) during splenoportography (CTSP). Methods.. Thirty patients refferred for CTSP were included in the study. Attenuation was measured at different time after contrast medium injection, and time-attenuation curves were created. Enhancement characteristics were evaluated, and the parenchyma-to-tumor difference of attenuation were compared. Results.. CTSP led to high parenchymal enhancement. The highest enhancement value in the left lobe was (218. 0±53. 2) Hu and (246.0± 60. 2) Hu in the right lobe. The difference between the right and left lobes was statistically significant (P<0. 05); The parenchyma-to-tumor difference of (65.3± 25.6) Hu was observed during scanning after injection. Conclusion: The high levels of liver parenchymal enhancement and parenchyma-to-lesion contrast can be achieved within the scanning time with CTSP.

  18. Estimation of absorbed dose of radiosensitive organs and effective sose in patients underwent abdominopelvic spiral CT scan using impact CT patient dosimetry

    Directory of Open Access Journals (Sweden)

    Ayoub Amirnia

    2017-05-01

    Full Text Available Background: Due to the presence of radiosensitive organs in the abdominopelvic region and increasing the number of requests for CT scan examinations, concerns about increasing radiation doses in patients has been greatly elevated. Therefore, the goal of this study was to determine the absorbed dose of radiosensitive organs and the effective dose in patients underwent abdominopelvic CT scan using ImPACT CT patient dosimetry Calculator (version 1.0.4, Imaging Performance Assessment on Computed Tomography, www.impactscan.org. Methods: This prospective cross-sectional study was conducted in Imam Reza Hospital from November to February 2015 February 2015 in the Imam Reza Hospital, in Urmia, Iran. The demographic and dosimetric information of 100 patients who underwent abdominopelvic CT scan in a 6-slice CT scanner were obtained through the data collection forms. The demographic data of the patients included age, weight, gender, and BMI. The dosimetric parameters included pitch value, CT dose volume index (CTDIvol, dose-length product (DLP, tube voltage, tube current, exposure time, collimation size, scan length, and scan time. To determine the absorbed dose of radiosensitive organs and also the effective dose in patients, ImPACT CT patient dosimetry calculator was used. Results: The results of this study demonstrated that the mean and standard deviation (SD of patients' effective dose in abdominopelvic CT scan was 4.927±0.164 mSv. The bladder in both genders had the greatest mean organ dose, which was 64.71±17.15 mGy for men and 77.56±18.48 mGy for women (P<0.001. Conclusion: The effective dose values of this examination are in the same range as previous studies, as well as International Commission on Radiological Protection (ICRP recommendations. However, the radiation dose from CT scan has the largest contribution to the medical imaging. According to the ALARA principle, it is recommended that the scan parameters, especially mAs, should be

  19. Head CT: Image quality improvement with ASIR-V using a reduced radiation dose protocol for children.

    Science.gov (United States)

    Kim, Hyun Gi; Lee, Ho-Joon; Lee, Seung-Koo; Kim, Hyun Ji; Kim, Myung-Joon

    2017-09-01

    To investigate the quality of images reconstructed with adaptive statistical iterative reconstruction V (ASIR-V), using pediatric head CT protocols. A phantom was scanned at decreasing 20% mA intervals using our standard pediatric head CT protocols. Each study was then reconstructed at 10% ASIR-V intervals. After the phantom study, we reduced mA by 10% in the protocol for V and by 30% in the protocol for 3- to 15-year-old patients and applied 40% ASIR-V. Increasing the percentage of ASIR-V resulted in lower noise and higher contrast-to-noise ratio (CNR) and preserved spatial resolution in the phantom study. Compared to a conventional-protocol, reduced-dose protocol with ASIR-V achieved 12.8% to 34.0% of dose reduction and showed images of lower noise (9.22 vs. 10.73, P = 0.043) and higher CNR in different levels (centrum semiovale, 2.14 vs. 1.52, P = 0.003; basal ganglia, 1.46 vs. 1.07, P = 0.001; and cerebellum, 2.18 vs. 1.33, P V. Use of ASIR-V allowed a 12.8% to 34.0% dose reduction in each age group with potential to improve image quality. • It is possible to reduce radiation dose and improve image quality with ASIR-V. • We improved noise and CNR and decreased radiation dose. • Sharpness improved with ASIR-V. • Total radiation dose was decreased by 12.8% to 34.0%.

  20. Improved image quality of cone beam CT scans for radiotherapy image guidance using fiber-interspaced antiscatter grid

    Energy Technology Data Exchange (ETDEWEB)

    Stankovic, Uros; Herk, Marcel van; Ploeger, Lennert S.; Sonke, Jan-Jakob, E-mail: j.sonke@nki.nl [Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam 1066 CX (Netherlands)

    2014-06-15

    Purpose: Medical linear accelerator mounted cone beam CT (CBCT) scanner provides useful soft tissue contrast for purposes of image guidance in radiotherapy. The presence of extensive scattered radiation has a negative effect on soft tissue visibility and uniformity of CBCT scans. Antiscatter grids (ASG) are used in the field of diagnostic radiography to mitigate the scatter. They usually do increase the contrast of the scan, but simultaneously increase the noise. Therefore, and considering other scatter mitigation mechanisms present in a CBCT scanner, the applicability of ASGs with aluminum interspacing for a wide range of imaging conditions has been inconclusive in previous studies. In recent years, grids using fiber interspacers have appeared, providing grids with higher scatter rejection while maintaining reasonable transmission of primary radiation. The purpose of this study was to evaluate the impact of one such grid on CBCT image quality. Methods: The grid used (Philips Medical Systems) had ratio of 21:1, frequency 36 lp/cm, and nominal selectivity of 11.9. It was mounted on the kV flat panel detector of an Elekta Synergy linear accelerator and tested in a phantom and a clinical study. Due to the flex of the linac and presence of gridline artifacts an angle dependent gain correction algorithm was devised to mitigate resulting artifacts. Scan reconstruction was performed using XVI4.5 augmented with inhouse developed image lag correction and Hounsfield unit calibration. To determine the necessary parameters for Hounsfield unit calibration and software scatter correction parameters, the Catphan 600 (The Phantom Laboratory) phantom was used. Image quality parameters were evaluated using CIRS CBCT Image Quality and Electron Density Phantom (CIRS) in two different geometries: one modeling head and neck and other pelvic region. Phantoms were acquired with and without the grid and reconstructed with and without software correction which was adapted for the different

  1. CT120: A New Potential Target for c-Myc in Head and Neck Cancers.

    Science.gov (United States)

    Baltaci, Elif; Seyhan, Betül; Baykara, Onur; Buyru, Nur

    2017-01-01

    Background: CT120 is a universally expressed protein with seven transmembrane domains. It functions in cell proliferation, survival and apoptosis by activating Raf/MEK/ERK and PI3K/Akt signaling pathways. Evidence suggests that CT120 plays important roles in lung carcinogenesis and oncogenic pathway activation. c-Myc is an important transcription factor modulating cell progression, apoptosis and cellular transformation. Previous studies have shown that MYC gene is amplified in many types of cancer including head and neck squamous cell carcinoma (HNSCC). Myc can regulate expression of many genes by binding to E-boxes. The aim of this study was to investigate the relationship between c-Myc protein and CT120 gene. Methods: Tumor and normal tissue samples from 50 patients with HNSCC were investigated with chromatin immunoprecipitation assay (ChIP), Illumina MiSeq, bisulphite sequencing and qRT-PCR. Results: c-Myc binds to all E-boxes except E-box 5 on CT120 promoter. The CpG dinucleotides were found to be partially methylated in all tumor and normal tissue samples. Bisulphite sequencing showed a 10% down-regulation in the methylation levels of the tumor tissues. CT120 gene was hypomethylated and up-regulated in 56% of the tumor tissue samples. Expression of c-Myc was significantly higher in tumor tissues than in non-cancerous tissue samples. MYC was overexpressed in 68% of the tumor tissue samples compared to normal tissues. The mean MYC levels were 2.42-fold higher in the tumor tissue samples. In 48% of the tumor tissues, MYC and CT120A mRNA were up- or down-regulated simultaneously (pc-Myc and it contributes to cancer progression in HNSCC.

  2. In vitro dose measurements in a human cadaver with abdomen/pelvis CT scans

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Da; Padole, Atul; Li, Xinhua; Singh, Sarabjeet; Khawaja, Ranish Deedar Ali; Lira, Diego; Shi, Jim Q.; Otrakji, Alexi; Kalra, Mannudeep K.; Liu, Bob, E-mail: bliu7@mgh.harvard.edu [Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Liu, Tianyu; Xu, X. George [Nuclear Engineering Program, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2014-09-15

    Purpose: To present a study of radiation dose measurements with a human cadaver scanned on a clinical CT scanner. Methods: Multiple point dose measurements were obtained with high-accuracy Thimble ionization chambers placed inside the stomach, liver, paravertebral gutter, ascending colon, left kidney, and urinary bladder of a human cadaver (183 cm in height and 67.5 kg in weight) whose abdomen/pelvis region was scanned repeatedly with a multidetector row CT. The flat energy response and precision of the dosimeters were verified, and the slight differences in each dosimeter's response were evaluated and corrected to attain high accuracy. In addition, skin doses were measured for radiosensitive organs outside the scanned region with OSL dosimeters: the right eye, thyroid, both nipples, and the right testicle. Three scan protocols were used, which shared most scan parameters but had different kVp and mA settings: 120-kVp automA, 120-kVp 300 mA, and 100-kVp 300 mA. For each protocol three repeated scans were performed. Results: The tube starting angle (TSA) was found to randomly vary around two major conditions, which caused large fluctuations in the repeated point dose measurements: for the 120-kVp 300 mA protocol this angle changed from approximately 110° to 290°, and caused 8% − 25% difference in the point dose measured at the stomach, liver, colon, and urinary bladder. When the fluctuations of the TSA were small (within 5°), the maximum coefficient of variance was approximately 3.3%. The soft tissue absorbed doses averaged from four locations near the center of the scanned region were 27.2 ± 3.3 and 16.5 ± 2.7 mGy for the 120 and 100-kVp fixed-mA scans, respectively. These values were consistent with the corresponding size specific dose estimates within 4%. The comparison of the per-100-mAs tissue doses from the three protocols revealed that: (1) dose levels at nonsuperficial locations in the TCM scans could not be accurately deduced by simply scaling

  3. A Survey of Pediatric CT Protocols and Radiation Doses in South Korean Hospitals to Optimize the Radiation Dose for Pediatric CT Scanning.

    Science.gov (United States)

    Hwang, Jae-Yeon; Do, Kyung-Hyun; Yang, Dong Hyun; Cho, Young Ah; Yoon, Hye-Kyung; Lee, Jin Seong; Koo, Hyun Jung

    2015-12-01

    Children are at greater risk of radiation exposure than adults because the rapidly dividing cells of children tend to be more radiosensitive and they have a longer expected life time in which to develop potential radiation injury. Some studies have surveyed computed tomography (CT) radiation doses and several studies have established diagnostic reference levels according to patient age or body size; however, no survey of CT radiation doses with a large number of patients has yet been carried out in South Korea. The aim of the present study was to investigate the radiation dose in pediatric CT examinations performed throughout South Korea. From 512 CT (222 brain CT, 105 chest CT, and 185 abdominopelvic CT) scans that were referred to our tertiary hospital, a dose report sheet was available for retrospective analysis of CT scan protocols and dose, including the volumetric CT dose index (CTDIvol), dose-length product (DLP), effective dose, and size-specific dose estimates (SSDE). At 55.2%, multiphase CT was the most frequently performed protocol for abdominopelvic CT. Tube current modulation was applied most often in abdominopelvic CT and chest CT, accounting for 70.1% and 62.7%, respectively. Regarding the CT dose, the interquartile ranges of the CTDIvol were 11.1 to 22.5 (newborns), 16.6 to 39.1 (≤1 year), 14.6 to 41.7 (2-5 years), 23.5 to 44.1 (6-10 years), and 31.4 to 55.3 (≤15 years) for brain CT; 1.3 to 5.7 (≤1 year), 3.9 to 6.8 (2-5 years), 3.9 to 9.3 (6-10 years), and 7.7 to 13.8 (≤15 years) for chest CT; and 4.0 to 7.5 (≤1 year), 4.2 to 8.9 (2-5 years), 5.7 to 12.4 (6-10 years), and 7.6 to 16.6 (≤15 years) for abdominopelvic CT. The SSDE and CTDIvol were well correlated for patients CT in South Korea. The CTDIvol, DLP, and effective dose were generally lower than in German and UK surveys, except in certain age groups.

  4. Cervical CT scan-guided epidural blood patches for spontaneous intracranial hypotension.

    Science.gov (United States)

    Maingard, Julian; Giles, Lauren; Marriott, Mark; Phal, Pramit M

    2015-12-01

    We describe two patients with spontaneous intracranial hypotension (SIH), presenting with postural headache due to C1-C2 cerebrospinal fluid (CSF) leak. Both patients were refractory to lumbar epidural blood patching (EBP), and subsequently underwent successful CT scan-guided cervical EBP. SIH affects approximately 1 in 50,000 patients, with females more frequently affected. Its associated features are variable, and as such, misdiagnosis is common. Therefore, imaging plays an important role in the diagnostic workup of SIH and can include MRI of the brain and spine, CT myelogram, and radionuclide cisternography. In patients with an established diagnosis and confirmed CSF leak, symptoms will usually resolve with conservative management. However, in a select subgroup of patients, the symptoms are refractory to medical management and require more invasive therapies. In patients with cervical leaks, EBP in the cervical region is an effective management approach, either in close proximity to, or directly targeting a dural defect. CT scan-guided cervical EBP is an effective treatment approach in refractory SIH, and should be considered in those patients who are refractory to conservative management.

  5. MRI and brain spect findings in patients with unilateral temporal lobe epilepsy and normal CT scan

    Directory of Open Access Journals (Sweden)

    P.G. Carrilho

    1994-06-01

    Full Text Available 26 patients with temporal lobe epilepsy clinically documented by several abnormal interictal surface EEGs with typical unitemporal epileptiform activity and a normal CT scan were studied. Interictal99mTC HMPAO brain SPECT and MRI were performed in all subjects. Abnormalities were shown in 61.5% of MRI (n=16 and 65.4% of SPECT (n=17. Hippocampal atrophy associated to a high signal on T2-weighted MRI slices suggesting mesial temporal sclerosis was the main finding (n=12; 75% of abnormal MRI. MRI correlated well to surface EEG in 50% (n=13. There was also a good correlation between MRI and SPECT in 30.7% (n=8. SPECT and EEG were in agreement in 57.7% (n=l5. MRI, SPECT and EEG were congruent in 26.9% (n=7. These results support the usefulness of interictal brain SPECT and MRI in detecting lateralized abnormalities in temporal lobe epilepsy. On the other hand, in two cases, interictal SPECT correlated poorly with surface EEG. This functional method should not be used isolately in the detection of temporal lobe foci. MRI is more useful than CT as a neuroimaging technique in temporal lobe epilepsy. It may detect small structural lesions and mesial temporal lobe sclerosis which are not easily seen with traditional CT scanning.

  6. Automatic Calibration Method of Voxel Size for Cone-beam 3D-CT Scanning System

    CERN Document Server

    Yang, Min; Liu, Yipeng; Men, Fanyong; Li, Xingdong; Liu, Wenli; Wei, Dongbo

    2013-01-01

    For cone-beam three-dimensional computed tomography (3D-CT) scanning system, voxel size is an important indicator to guarantee the accuracy of data analysis and feature measurement based on 3D-CT images. Meanwhile, the voxel size changes with the movement of the rotary table along X-ray direction. In order to realize the automatic calibration of the voxel size, a new easily-implemented method is proposed. According to this method, several projections of a spherical phantom are captured at different imaging positions and the corresponding voxel size values are calculated by non-linear least square fitting. Through these interpolation values, a linear equation is obtained, which reflects the relationship between the rotary table displacement distance from its nominal zero position and the voxel size. Finally, the linear equation is imported into the calibration module of the 3D-CT scanning system, and when the rotary table is moving along X-ray direction, the accurate value of the voxel size is dynamically expo...

  7. [Lung cancer screening with low-dose thoracic CT-scan in the Somme area].

    Science.gov (United States)

    Leleu, O; Auquier, M; Carre, O; Chauffert, B; Dubreuil, A; Petigny, V; Trancart, B; Berna, P; Jounieaux, V

    2017-03-01

    This feasibility trial proposes to set up in the department of the Somme an annual screening for lung cancer with low-dose thoracic CT. It responds to the first objective of the third cancer plan and follows the publication of the results of the National Lung Screening Trial in 2011. The method of this study is to use the existing networks among and between healthcare professionals and the departmental cancer screening structure. The inclusion criteria will be those of the National Lung Screening Trial. Screening will be proposed by treating physicians and chest physicians. The CT-scan will be performed in radiological centers that adhere to the good practice charter for low radiation scanning. A copy of CT results will be sent to the departmental structure of cancer screening (ADEMA80) which will ensure traceability and will perform statistical analysis. The study received funding from the Agence régionale de santé de la Picardie and la ligue contre le cancer. The primary endpoints of this screening will be the number of cancers diagnosed and the survival of the patients. The follow-up of positive examinations, delays in management and the level of participation will also be assessed. Copyright © 2016 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  8. Case report of subcapsular hemorrhage of the liver in the newborn. Diagnosed and observed by CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Masao; Matsumura, Takafumi; Esumi, Noriko; Tsunamoto, Kentaro; Iino, Shigeru (Kyoto Prefectural Univ. of Medicine (Japan))

    1982-11-01

    A recent case of subcapsular hemorrhage of the liver in a newborn showed that abdominal CT scan was highly useful in the diagnosis of this disease and the follow-up of the healing mechanism of the intrahepatic hemorrhagic lesion.

  9. Challenges in integrating 18FDG PET-CT into radiotherapy planning of head and neck cancer.

    Science.gov (United States)

    Dandekar, P; Partridge, M; Kazi, R; Nutting, C; Harrington, K; Newbold, K

    2010-01-01

    Radiotherapy forms one of the major treatment modalities for head and neck cancers (HNC), and precision radiotherapy techniques, such as intensity-modulated radiotherapy require accurate target delineation to ensure success of the treatment. Conventionally used imaging modalities, such as X-ray computed tomography (CT) and magnetic resonance imaging are used to delineate the tumor. Imaging, such as positron emission tomography (PET)-CT, which combines the functional and anatomic modalities, is increasingly being used in the management of HNC. Currently, 18-fluorodeoxyglucose is the most commonly used radioisotope, which is accumulated in areas of high glucose uptake, such as the tumor tissue. Because most disease recurrences are within the high-dose radiotherapy volume, defining a biological target volume for radiotherapy boost is an attractive approach to improve the results. There are many challenges in employing the PET-CT for radiotherapy planning, such as patient positioning, target edge definition, and use of new PET tracers, which represent various functional properties, such as hypoxia, protein synthesis, and proliferation. The role of PET-CT for radiotherapy planning is ever expanding and more clinical data underlining the advantages and challenges in this approach are emerging. In this article, we review the current clinical evidence for the application of functional imaging to radiotherapy planning and discuss some of the current challenges and possible solutions that have been suggested to date.

  10. PET/CT in Radiotherapy Planning for Head and Neck Cancer

    Directory of Open Access Journals (Sweden)

    Katie eNewbold

    2012-12-01

    Full Text Available The use of PET/CT as an adjunct in radiotherapy planning is an attractive option in head and neck cancer (HNC for several reasons. First, with potentially better identification of the disease extent i.e. staging, the risk of geographical miss of radiation delivery to the gross tumour volume (GTV is reduced. Second, in characterising the biological behaviour of the disease for example, areas of hypoxia, rich or poor vascularity or high cell proliferation, PET/CT can identify biological target volumes (BTVs either for escalation of radiation dose or to predict the requirement for the addition of a radiosensitiser or alternative treatment strategies. 18F-FDG is the most common tracer used in oncology studies, but many other tracers have been investigated with several entering clinical practice, although these remain predominantly in the research domain in HNC. These issues will be discussed in this review.

  11. Low-Dose and Scatter-Free Cone-Beam CT Imaging Using a Stationary Beam Blocker in a Single Scan: Phantom Studies

    Directory of Open Access Journals (Sweden)

    Xue Dong

    2013-01-01

    Full Text Available Excessive imaging dose from repeated scans and poor image quality mainly due to scatter contamination are the two bottlenecks of cone-beam CT (CBCT imaging. Compressed sensing (CS reconstruction algorithms show promises in recovering faithful signals from low-dose projection data but do not serve well the needs of accurate CBCT imaging if effective scatter correction is not in place. Scatter can be accurately measured and removed using measurement-based methods. However, these approaches are considered unpractical in the conventional FDK reconstruction, due to the inevitable primary loss for scatter measurement. We combine measurement-based scatter correction and CS-based iterative reconstruction to generate scatter-free images from low-dose projections. We distribute blocked areas on the detector where primary signals are considered redundant in a full scan. Scatter distribution is estimated by interpolating/extrapolating measured scatter samples inside blocked areas. CS-based iterative reconstruction is finally carried out on the undersampled data to obtain scatter-free and low-dose CBCT images. With only 25% of conventional full-scan dose, our method reduces the average CT number error from 250 HU to 24 HU and increases the contrast by a factor of 2.1 on Catphan 600 phantom. On an anthropomorphic head phantom, the average CT number error is reduced from 224 HU to 10 HU in the central uniform area.

  12. Acute pyelonephritis: role of enhanced CT scan in the prediction of clinical outcome

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Byung June; Kim, Ki Whang; Yu, Jeong Sik; Kim, Jai Keun; Yoon, Sang Wook; Ha, Sung Kyu; Park, Chong Hoon [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-04-01

    To correlate the CT findings of acute pyelonephritis with its outcome and with clinical data. Thirty five contrast enhanced CT scans in patients diagnosed as suffering from acute pyelonephritis were retrospectively analyzed. Findings based on the morphology of perfusion defect in the renal parenchyma were classified as normal, focal wedge, multifocal wedge, focal mass, or mixed form composed of wedge and mass. These findings were correlated with clinical data such as degree of fever, leukocytosis, the period after antibiotic treatment during which fever was reduced, and the presence of pyuria in each group Analysis was then performed. Perfusion defects were seen in 23 of 35 cases, and their morphology was classified as follow; focal wedge (n=2), multifocal wedge (n=8), focal mass (n=4), and mixed form (n=9). Twelve cases (34.3%) showed no perfusion defect. The duration of fever was significantly prolonged in patients with focal mass form (p < .05). There was no significant correlation between the morphology of perfusion defect, bilaterality, and other clinical factors. The present study shows that the clinical course of the focal mass form of perfusion defect, as seen on CT, is different from that of other types. CT could be effective in predicting clinical progress and the outcome of treatment in cases of acute pyelonephritis.

  13. Reduction of Cone-Beam CT scan time without compromising the accuracy of the image registration in IGRT

    DEFF Research Database (Denmark)

    Westberg, Jonas; Jensen, Henrik R; Bertelsen, Anders;

    2010-01-01

    In modern radiotherapy accelerators are equipped with 3D cone-beam CT (CBCT) which is used to verify patient position before treatment. The verification is based on an image registration between the CBCT acquired just before treatment and the CT scan made for the treatment planning. The purpose...... of this study is to minimise the scan time of the CBCT without compromising the accuracy of the image registration in IGRT....

  14. Pharmacological control of head motion during cerebral blood flow imaging with CT or MRI.

    Science.gov (United States)

    Sesay, M; Jeannin, A; Moonen, C T W; Dousset, V; Maurette, P

    2009-06-01

    Uncontrolled head motion during CT/MRI cerebral blood flow (CBF) imaging has been estimated between 3 and 15% of the cases. We present a pharmacological approach which permitted us to maintain the incident at 0.06% with few side effects. The protocol involves the systematic use of general anesthesia (sevoflurane) in children below five years and those with mental retardation. In anxious, claustrophobic or agitated adults, mild sedation with propofol, midazolam or hydroxyzine was used with mild effects on CBF. We strongly recommend the availability of basic cardiorespiratory resuscitation equipment and a recovery room before any sedation or general anesthesia is undertaken.

  15. Lens of the eye dose calculation for neuro-interventional procedures and CBCT scans of the head

    Science.gov (United States)

    Xiong, Zhenyu; Vijayan, Sarath; Rana, Vijay; Jain, Amit; Rudin, Stephen; Bednarek, Daniel R.

    2016-03-01

    The aim of this work is to develop a method to calculate lens dose for fluoroscopically-guided neuro-interventional procedures and for CBCT scans of the head. EGSnrc Monte Carlo software is used to determine the dose to the lens of the eye for the projection geometry and exposure parameters used in these procedures. This information is provided by a digital CAN bus on the Toshiba Infinix C-Arm system which is saved in a log file by the real-time skin-dose tracking system (DTS) we previously developed. The x-ray beam spectra on this machine were simulated using BEAMnrc. These spectra were compared to those determined by SpekCalc and validated through measured percent-depth-dose (PDD) curves and half-value-layer (HVL) measurements. We simulated CBCT procedures in DOSXYZnrc for a CTDI head phantom and compared the surface dose distribution with that measured with Gafchromic film, and also for an SK150 head phantom and compared the lens dose with that measured with an ionization chamber. Both methods demonstrated good agreement. Organ dose calculated for a simulated neuro-interventional-procedure using DOSXYZnrc with the Zubal CT voxel phantom agreed within 10% with that calculated by PCXMC code for most organs. To calculate the lens dose in a neuro-interventional procedure, we developed a library of normalized lens dose values for different projection angles and kVp's. The total lens dose is then calculated by summing the values over all beam projections and can be included on the DTS report at the end of the procedure.

  16. CT Scan Features of Presumptive Haemorrhagic Stroke in a Dog with Cushing’s Disease

    Directory of Open Access Journals (Sweden)

    A. Liotta

    2014-01-01

    Full Text Available A 9-year-old, intact male, Brie’s shepherd dog, with a 10-day history of depression and tachypnoea developed signs of central neurological dysfunction. 16 Multislice Computed Tomography (CT pre- and postcontrast studies of the brain revealed a single intra-axial homogeneous well-circumscribed hyperattenuating (+/− 62 HU and noncontrast-enhancing area, 5 mm in diameter, in the caudal part of the mesencephalon. This finding was highly suggestive of a haemorrhagic event. A pituitary-dependent hyperadrenocorticism (PDH was identified and is considered likely to be the underlying cause. A repeat CT scan examination, 2 months later, showed almost complete resolution of the brain lesion. The present case describes a solitary 5 mm diameter lesion: the result of intracranial haemorrhage in a dog with presumed PDH.

  17. Observation on local and/or unilateral pathologic changes in renal cortex by CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Isao; Shinoda, Akira (Kanazawa Medical Univ. (Japan)); Onouchi, Zengoro; Saito, Yasuhito; Matsuura, Hajime

    1984-03-01

    Renal cortex visualization after bolus injection of contrast medium using computed tomography (CT), was obtained in 132 consecutive patients with renal disease. Local pathological changes in the functioning cortex of the kidney were easily recognized in 37 cases and unilateral cortical thinning was found in 17 cases. Unilateral poor enhancement of the cortex with bilateral equal cortex thickness was noted in 4 cases. Several representative cases are reported with CT scans. The cortex at the posterior aspect of the renal graft compressed on psoas muscle was thinner than that at the anterior aspect in renal transplant cases. The macroscopic observation on the renal cortex presented here is far superior to the nephrogram or pyelogram seen through conventional radiographic examination. In vivo cortex visualization will correlate renal biopsy findings with the state of the whole kidney.

  18. Initial experience with optical-CT scanning of RadBall Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Oldham, M; Clift, C; Thomas, A; Farfan, E; Foley, T; Jannik, T; Adamovics, J; Holmes, C; Stanley, S, E-mail: Mark.Oldham@Duke.ed

    2010-11-01

    The RadBall dosimeter is a novel device for providing 3-D information on the magnitude and distribution of contaminant sources of unknown radiation in a given hot cell, glovebox, or contaminated room. The device is presently under evaluation by the National Nuclear Lab (NNL, UK) and the Savannah River National Laboratory (SRNL, US), for application as a diagnostic device for such unknown contaminants in the nuclear industry. A critical component of the technique is imaging the dose distribution recorded in the RadBall using optical-CT scanning. Here we present our initial investigations using the Duke Mid-sized Optical-CT Scanner (DMOS) to image dose distributions deposited in RadBalls exposed to a variety of radiation treatments.

  19. Giant aneurysm of the distal anterior cerebral artery simulating brain tumor on CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Shigemori, Minoru; Kawaba, Tomoyuki; Kuramoto, Shinken (Kurume Univ., Fukuoka (Japan). School of Medicine); Ogata, Takeyuki; Yoshimura, Kyoko

    1982-08-01

    A successfully treated case with a giant aneurysm of the distal anterior cerebral artery which simulated brain tumor on computerized tomography (CT) is reported. In a 69-year-old woman suffering with a mild headache and a weakness in the left leg, a plain skull film revealed a ballooning of the sella turcica and an erosion of the dorsum. A CT scan showed a round or oval high-density area at the medial site of the right frontal lobe which was associated with an extensive low-density area. Curviliner calcification was also noted. A marked attenuation of the medial site of the mass lesion was demonstrated with contrast enhancement. A left-carotid angiogram demonstrated a large aneurysm at the distal-branching point of the anterior cerebral artery. Radical treatment for the aneurysm was performed. The postoperative course was uneventful, and the low-density area around the aneurysm disappeared within 6 weeks after the operation.

  20. Automated Detection of Healthy and Diseased Aortae from Images Obtained by Contrast-Enhanced CT Scan

    Directory of Open Access Journals (Sweden)

    Michael Gayhart

    2013-01-01

    Full Text Available Purpose. We developed the next stage of our computer assisted diagnosis (CAD system to aid radiologists in evaluating CT images for aortic disease by removing innocuous images and highlighting signs of aortic disease. Materials and Methods. Segmented data of patient’s contrast-enhanced CT scan was analyzed for aortic dissection and penetrating aortic ulcer (PAU. Aortic dissection was detected by checking for an abnormal shape of the aorta using edge oriented methods. PAU was recognized through abnormally high intensities with interest point operators. Results. The aortic dissection detection process had a sensitivity of 0.8218 and a specificity of 0.9907. The PAU detection process scored a sensitivity of 0.7587 and a specificity of 0.9700. Conclusion. The aortic dissection detection process and the PAU detection process were successful in removing innocuous images, but additional methods are necessary for improving recognition of images with aortic disease.

  1. Low-dose computed tomography scans with automatic exposure control for patients of different ages undergoing cardiac PET/CT and SPECT/CT.

    Science.gov (United States)

    Yang, Ching-Ching; Yang, Bang-Hung; Tu, Chun-Yuan; Wu, Tung-Hsin; Liu, Shu-Hsin

    2017-06-01

    This study aimed to evaluate the efficacy of automatic exposure control (AEC) in order to optimize low-dose computed tomography (CT) protocols for patients of different ages undergoing cardiac PET/CT and single-photon emission computed tomography/computed tomography (SPECT/CT). One PET/CT and one SPECT/CT were used to acquire CT images for four anthropomorphic phantoms representative of 1-year-old, 5-year-old and 10-year-old children and an adult. For the hybrid systems investigated in this study, the radiation dose and image quality of cardiac CT scans performed with AEC activated depend mainly on the selection of a predefined image quality index. Multiple linear regression methods were used to analyse image data from anthropomorphic phantom studies to investigate the effects of body size and predefined image quality index on CT radiation dose in cardiac PET/CT and SPECT/CT scans. The regression relationships have a coefficient of determination larger than 0.9, indicating a good fit to the data. According to the regression models, low-dose protocols using the AEC technique were optimized for patients of different ages. In comparison with the standard protocol with AEC activated for adult cardiac examinations used in our clinical routine practice, the optimized paediatric protocols in PET/CT allow 32.2, 63.7 and 79.2% CT dose reductions for anthropomorphic phantoms simulating 10-year-old, 5-year-old and 1-year-old children, respectively. The corresponding results for cardiac SPECT/CT are 8.4, 51.5 and 72.7%. AEC is a practical way to reduce CT radiation dose in cardiac PET/CT and SPECT/CT, but the AEC settings should be determined properly for optimal effect. Our results show that AEC does not eliminate the need for paediatric protocols and CT examinations using the AEC technique should be optimized for paediatric patients to reduce the radiation dose as low as reasonably achievable.

  2. Self-directed learning modules of CT scan images to improve students' perception of gross anatomy.

    Science.gov (United States)

    Kumar, Pananghat Achutha; Jothi, Ramakrishnan; Mathivanan, Dharmalingam

    2016-01-01

    A contemporary anatomy curriculum that aims to be clinically relevant requires medical students to be introduced to radiological anatomy in the preclinical years. Ideally, the curriculum should also support self-directed learning, a habit best instilled early. Based on these educational requirements, we designed an interesting and clinically-meaningful program of self-learning modules in radiological anatomy to augment students' learning of gross anatomy. The program is guided by current theories of learning, which emphasize an individualized learning pace for students. This program uses enlarged computerized tomography (CT) scan images and associated resource materials. Scans are posted on the first day of the week in a public area for students to review on their own time. On the second day penciled outlines of important structures are provided to help students identify structures, and students are encouraged to discuss the images with faculty. On the last day of the week the identity of the structures are revealed to students. An open-ended questionnaire used to evaluate the program revealed that 95.5% of students used the program and a great majority recommended the program should be continued for future students. The present program enhances learning of gross anatomical relations through having students use visual clues in logically interpreting unlabeled CT scans in an organized and sequential way. The program promotes self-directed learning. In addition to its use with preclinical students, the modules might also help students in the clinical phase of the curriculum bolster their knowledge of spatial anatomy.

  3. Synchrotron scanning reveals the palaeoneurology of the head-butting Moschops capensis (Therapsida, Dinocephalia

    Directory of Open Access Journals (Sweden)

    Julien Benoit

    2017-08-01

    Full Text Available Dinocephalian therapsids are renowned for their massive, pachyostotic and ornamented skulls adapted for head-to-head fighting during intraspecific combat. Synchrotron scanning of the tapinocephalid Moschops capensis reveals, for the first time, numerous anatomical adaptations of the central nervous system related to this combative behaviour. Many neural structures (such as the brain, inner ear and ophthalmic branch of the trigeminal nerve were completely enclosed and protected by bones, which is unusual for non-mammaliaform therapsids. The nearly complete ossification of the braincase enables precise determination of the brain cavity volume and encephalization quotient, which appears greater than expected for such a large and early herbivore. The practice of head butting is often associated with complex social behaviours and gregariousness in extant species, which are known to influence brain size evolution. Additionally, the plane of the lateral (horizontal semicircular canal of the bony labyrinth is oriented nearly vertically if the skull is held horizontally, which suggests that the natural position of the head was inclined about 60–65°to the horizontal. This is consistent with the fighting position inferred from osteology, as well as ground-level browsing. Finally, the unusually large parietal tube may have been filled with thick conjunctive tissue to protect the delicate pineal eye from injury sustained during head butting.

  4. Adaptive statistical iterative reconstruction and bismuth shielding for evaluation of dose reduction to the eye and image quality during head CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myeong Seong [The Korean National Cancer Center, Goyang (Korea, Republic of); Seoul National University, Seoul (Korea, Republic of); Choi, Ji Won [Jeonju University, Jeonju (Korea, Republic of); Kim, Sun Young [Hallym University of Graduate Studies, Seoul (Korea, Republic of); The Korean National Cancer Center, Goyang (Korea, Republic of); Kweon, Dae Cheol [Shinhan University, Uijeongbu (Korea, Republic of)

    2014-03-15

    There is a concern regarding the adverse effects of increasing radiation doses due to repeated computed tomography (CT) scans, especially in radiosensitive organs and portions thereof, such as the lenses of the eyes. Bismuth shielding with an adaptive statistical iterative reconstruction (ASIR) algorithm was recently introduced in our clinic as a method to reduce the absorbed radiation dose. This technique was applied to the lens of the eye during CT scans. The purpose of this study was to evaluate the reduction in the absorbed radiation dose and to determine the noise level when using bismuth shielding and the ASIR algorithm with the GE DC 750 HD 64-channel CT scanner for CT of the head of a humanoid phantom. With the use of bismuth shielding, the noise level was higher in the beam-hardening artifact areas than in the revealed artifact areas. However, with the use of ASIR, the noise level was lower than that with the use of bismuth alone; it was also lower in the artifact areas. The reduction in the radiation dose with the use of bismuth was greatest at the surface of the phantom to a limited depth. In conclusion, it is possible to reduce the radiation level and slightly decrease the bismuth-induced noise level by using a combination of ASIR as an algorithm process and bismuth as an in-plane hardware-type shielding method.

  5. Multiplanar reconstructed CT images increased depiction of intracranial hemorrhages in pediatric head trauma

    Energy Technology Data Exchange (ETDEWEB)

    Langford, Stacey; Panigrahy, Ashok; Narayanan, Srikala; Hwang, Misun; Fitz, Charles; Flom, Lynda; Lee, Vincent Kyu; Zuccoli, Giulio [Children' s Hospital of Pittsburgh of UPMC, Department of Radiology, Section of Neuroradiology, Pittsburgh, PA (United States)

    2015-12-15

    The benefits of multiplanar reconstructed images (MPR) of unenhanced axial head computed tomography (CT) data have not been established in trauma patients younger than 3 years old, a population in which a reliable history and physical examination may be most difficult. We retrospectively evaluated unenhanced head CTs in pediatric trauma patients to investigate the various benefits of MPR in this age group. A total of 221 unenhanced head CTs performed for any case of head trauma (HT) on children younger than 3 years old were independently reviewed by two radiologists. Studies were reviewed first in the standard axial plane alone and then with the addition of MPR. Reviewers were asked to determine if the MPR affected the ability to make findings of hemorrhage, incidental findings, and artifacts. MPR improved the detection of hemorrhage in 14 cases (6.5 %, p-value < 0.01) and incidental findings in five cases (2.3 %, p-value < 0.05) as well as helped prove artifacts in five cases (2.3 %, p-value < 0.05). Routine use of MPR in HT patients younger than 3 years old has the potential to increase the detection of acute and incidental imaging findings. (orig.)

  6. Semi-automated method to measure pneumonia severity in mice through computed tomography (CT) scan analysis

    Science.gov (United States)

    Johri, Ansh; Schimel, Daniel; Noguchi, Audrey; Hsu, Lewis L.

    2010-03-01

    Imaging is a crucial clinical tool for diagnosis and assessment of pneumonia, but quantitative methods are lacking. Micro-computed tomography (micro CT), designed for lab animals, provides opportunities for non-invasive radiographic endpoints for pneumonia studies. HYPOTHESIS: In vivo micro CT scans of mice with early bacterial pneumonia can be scored quantitatively by semiautomated imaging methods, with good reproducibility and correlation with bacterial dose inoculated, pneumonia survival outcome, and radiologists' scores. METHODS: Healthy mice had intratracheal inoculation of E. coli bacteria (n=24) or saline control (n=11). In vivo micro CT scans were performed 24 hours later with microCAT II (Siemens). Two independent radiologists scored the extent of airspace abnormality, on a scale of 0 (normal) to 24 (completely abnormal). Using the Amira 5.2 software (Mercury Computer Systems), a histogram distribution of voxel counts between the Hounsfield range of -510 to 0 was created and analyzed, and a segmentation procedure was devised. RESULTS: A t-test was performed to determine whether there was a significant difference in the mean voxel value of each mouse in the three experimental groups: Saline Survivors, Pneumonia Survivors, and Pneumonia Non-survivors. It was found that the voxel count method was able to statistically tell apart the Saline Survivors from the Pneumonia Survivors, the Saline Survivors from the Pneumonia Non-survivors, but not the Pneumonia Survivors vs. Pneumonia Non-survivors. The segmentation method, however, was successfully able to distinguish the two Pneumonia groups. CONCLUSION: We have pilot-tested an evaluation of early pneumonia in mice using micro CT and a semi-automated method for lung segmentation and scoring system. Statistical analysis indicates that the system is reliable and merits further evaluation.

  7. SU-D-217A-06: Impact of Anterior-Posterior (AP) and Posterior-Anterior (PA) Scout Scans on the CT Radiation Dose in the Whole Body PET/CT Scan.

    Science.gov (United States)

    Luo, D; Pan, T

    2012-06-01

    CT can contribute over 50% of radiation dose in the whole body (WB) PET/CT scan. Tube current modulation (TCM) is a standard technique for reducing CT radiation dose to the patient by changing the tube current with the patient size, and is controlled by a very low-dose scoutscan, which assumes the patient is positioned at the center of the CT gantry opening. However, most patients are not positioned at the center due to practicality or to avoid claustrophobic or to reduce time of radiation exposure from the patient to the technologist. We study the impact of the AP and PA scout scans to the patient radiation exposure from CT. Ina retrospective study of 200 patients, each received two WB PET/CT scans: one with AP, and the other one with PA. The helical CT with TCM and PET acquisitions were identical in both scans. Separation of the two scans was about 10 months in average. The scans were performed on four GE PET/CT scanners: three 16- and one 64-slice with the same TCM settings. The 200patients were selected for the same scan coverage and similar body weight (difference = 3 kg). The tube current in each slice and average exposure tothe patient were recorded and compared. The AP scout caused lower radiation dose on 94% of the patients. Both the tube current, and radiation exposure were reduced by 46±30 mA and 1.6±1.0 mGy, respectively. The effective radiation dose is reduced by 1.7±1.2 mSv. These results were statistically significant (p<0.00001). The AP scout caused significantly less radiation dose than the PA scout in the CT scan of the whole-body PET/CT scan. Care should be taken to select theorientation of the scout scan to achieve appropriate radiation exposure to the patient when TCM is applied. © 2012 American Association of Physicists in Medicine.

  8. The application of metal artifact reduction (MAR) in CT scans for radiation oncology by monoenergetic extrapolation with a DECT scanner

    Energy Technology Data Exchange (ETDEWEB)

    Schwahofer, Andrea [German Cancer Research Center, Heidelberg (Germany). Dept. of Medical Physics in Radiation Oncology; Clinical Center Vivantes, Neukoelln (Germany). Dept. of Radiotherapy and Oncology; Baer, Esther [German Cancer Research Center, Heidelberg (Germany). Dept. of Medical Physics in Radiation Oncology; Kuchenbecker, Stefan; Kachelriess, Marc [German Cancer Research Center, Heidelberg (Germany). Dept. of Medical Physics in Radiology; Grossmann, J. Guenter [German Cancer Research Center, Heidelberg (Germany). Dept. of Medical Physics in Radiation Oncology; Ortenau Klinikum Offenburg-Gengenbach (Germany). Dept. of Radiooncology; Sterzing, Florian [Heidelberg Univ. (Germany). Dept. of Radiation Oncology; German Cancer Research Center, Heidelberg (Germany). Dept. of Radiotherapy

    2015-07-01

    Metal artifacts in computed tomography CT images are one of the main problems in radiation oncology as they introduce uncertainties to target and organ at risk delineation as well as dose calculation. This study is devoted to metal artifact reduction (MAR) based on the monoenergetic extrapolation of a dual energy CT (DECT) dataset. In a phantom study the CT artifacts caused by metals with different densities: aluminum (ρ{sub Al} = 2.7 g/cm{sup 3}), titanium (ρ{sub Ti} = 4.5 g/cm{sup 3}), steel (ρ{sub steel} = 7.9 g/cm{sup 3}) and tungsten (ρ{sub W} = 19.3 g/cm{sup 3}) have been investigated. Data were collected using a clinical dual source dual energy CT (DECT) scanner (Siemens Sector Healthcare, Forchheim, Germany) with tube voltages of 100 kV and 140 kV (Sn). For each tube voltage the data set in a given volume was reconstructed. Based on these two data sets a voxel by voxel linear combination was performed to obtain the monoenergetic data sets. The results were evaluated regarding the optical properties of the images as well as the CT values (HU) and the dosimetric consequences in computed treatment plans. A data set without metal substitute served as the reference. Also, a head and neck patient with dental fillings (amalgam ρ = 10 g/cm{sup 3}) was scanned with a single energy CT (SECT) protocol and a DECT protocol. The monoenergetic extrapolation was performed as described above and evaluated in the same way. Visual assessment of all data shows minor reductions of artifacts in the images with aluminum and titanium at a monoenergy of 105 keV. As expected, the higher the densities the more distinctive are the artifacts. For metals with higher densities such as steel or tungsten, no artifact reduction has been achieved. Likewise in the CT values, no improvement by use of the monoenergetic extrapolation can be detected. The dose was evaluated at a point 7 cm behind the isocenter of a static field. Small improvements (around 1%) can be seen with 105 ke

  9. The application of metal artifact reduction (MAR) in CT scans for radiation oncology by monoenergetic extrapolation with a DECT scanner.

    Science.gov (United States)

    Schwahofer, Andrea; Bär, Esther; Kuchenbecker, Stefan; Grossmann, J Günter; Kachelrieß, Marc; Sterzing, Florian

    2015-12-01

    Metal artifacts in computed tomography CT images are one of the main problems in radiation oncology as they introduce uncertainties to target and organ at risk delineation as well as dose calculation. This study is devoted to metal artifact reduction (MAR) based on the monoenergetic extrapolation of a dual energy CT (DECT) dataset. In a phantom study the CT artifacts caused by metals with different densities: aluminum (ρ Al=2.7 g/cm(3)), titanium (ρ Ti=4.5 g/cm(3)), steel (ρ steel=7.9 g/cm(3)) and tungsten (ρ W=19.3g/cm(3)) have been investigated. Data were collected using a clinical dual source dual energy CT (DECT) scanner (Siemens Sector Healthcare, Forchheim, Germany) with tube voltages of 100 kV and 140 kV(Sn). For each tube voltage the data set in a given volume was reconstructed. Based on these two data sets a voxel by voxel linear combination was performed to obtain the monoenergetic data sets. The results were evaluated regarding the optical properties of the images as well as the CT values (HU) and the dosimetric consequences in computed treatment plans. A data set without metal substitute served as the reference. Also, a head and neck patient with dental fillings (amalgam ρ=10 g/cm(3)) was scanned with a single energy CT (SECT) protocol and a DECT protocol. The monoenergetic extrapolation was performed as described above and evaluated in the same way. Visual assessment of all data shows minor reductions of artifacts in the images with aluminum and titanium at a monoenergy of 105 keV. As expected, the higher the densities the more distinctive are the artifacts. For metals with higher densities such as steel or tungsten, no artifact reduction has been achieved. Likewise in the CT values, no improvement by use of the monoenergetic extrapolation can be detected. The dose was evaluated at a point 7 cm behind the isocenter of a static field. Small improvements (around 1%) can be seen with 105 keV. However, the dose uncertainty remains of the order of 10

  10. Improved image quality and radiation dose reduction in liver dynamic CT scan with the protocol change

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yu Jin; Cho, Pyong Kon [Radiological Science, Catholic University of Daegu, Daegu (Korea, Republic of)

    2015-06-15

    The purpose is reducing radiation dose while maintaining of image quality in liver dynamic CT(LDCT) scan, by protocols generally used and the tube voltage set at a low level protocol compared to the radiation dose and image quality. The target is body mass index, 18.5-24 patients out of 40 patients who underwent the ACT(abdominal CT). Group A(tube voltage : 120 kVp, SAFIRE strength 1) of 20 people among 40 people, to apply the general abdominal CT scan protocol, group B(tube voltage : 100 kVp, apply SAFIRE strength 0-5) was 20 people, set a lower tube voltage. Image quality evaluation was setting a region of interest(ROI) in the liver parenchyma, aorta, superior mesenteric artery (SMA), celiac trunk, visceral fat of arterial phase. In the ROI were compared by measuring the noise, signal to noise ratio(SNR), contrast to noise ratio(CNR), CT number. In addition, qualitative assessments to evaluate two people in the rich professional experience in Radiology by 0-3 points. We compared the total radiation dose, dose length product(DLP) and effective dose, volume computed tomography dose index(CTDIvol). The higher SAFIRE in the tube voltage 100 kVp, noise is reduced, CT number was increased. Thus, SNR and CNR was increased higher the SAFIRE step. Compared with the tube voltage 120 kVp, noise, SNR, CNR was most similar in SAFIRE strength 2 and 3. Qualitative assessment SAFIRE strength 2 is the most common SAFIRE strength 2 the most common qualitative assessment, if the tube voltage of 100 kVp when the quality of the images better evaluated was SAFIRE strength 1. Dose was reduced from 21.69%, in 100 kVp than 120 kVp. In the case of a relatively high BMI is not LDCT scan, When it is shipped from the factory tube voltage is set higher, unnecessary radiation exposure when considering the reality that is concerned, when according to the results of this study, set a lower tube voltage and adjust the SAFIRE strength to 1 or 2, the radiation without compromising image quality

  11. Development of 1-year-old computational phantom and calculation of organ doses during CT scans using Monte Carlo simulation.

    Science.gov (United States)

    Pan, Yuxi; Qiu, Rui; Gao, Linfeng; Ge, Chaoyong; Zheng, Junzheng; Xie, Wenzhang; Li, Junli

    2014-09-21

    With the rapidly growing number of CT examinations, the consequential radiation risk has aroused more and more attention. The average dose in each organ during CT scans can only be obtained by using Monte Carlo simulation with computational phantoms. Since children tend to have higher radiation sensitivity than adults, the radiation dose of pediatric CT examinations requires special attention and needs to be assessed accurately. So far, studies on organ doses from CT exposures for pediatric patients are still limited. In this work, a 1-year-old computational phantom was constructed. The body contour was obtained from the CT images of a 1-year-old physical phantom and the internal organs were deformed from an existing Chinese reference adult phantom. To ensure the organ locations in the 1-year-old computational phantom were consistent with those of the physical phantom, the organ locations in 1-year-old computational phantom were manually adjusted one by one, and the organ masses were adjusted to the corresponding Chinese reference values. Moreover, a CT scanner model was developed using the Monte Carlo technique and the 1-year-old computational phantom was applied to estimate organ doses derived from simulated CT exposures. As a result, a database including doses to 36 organs and tissues from 47 single axial scans was built. It has been verified by calculation that doses of axial scans are close to those of helical scans; therefore, this database could be applied to helical scans as well. Organ doses were calculated using the database and compared with those obtained from the measurements made in the physical phantom for helical scans. The differences between simulation and measurement were less than 25% for all organs. The result shows that the 1-year-old phantom developed in this work can be used to calculate organ doses in CT exposures, and the dose database provides a method for the estimation of 1-year-old patient doses in a variety of CT examinations.

  12. Development of automated quantification of visceral and subcutaneous adipose tissue volumes from abdominal CT scans

    Science.gov (United States)

    Mensink, Sanne D.; Spliethoff, Jarich W.; Belder, Ruben; Klaase, Joost M.; Bezooijen, Roland; Slump, Cornelis H.

    2011-03-01

    This contribution describes a novel algorithm for the automated quantification of visceral and subcutaneous adipose tissue volumes from abdominal CT scans of patients referred for colorectal resection. Visceral and subcutaneous adipose tissue volumes can accurately be measured with errors of 1.2 and 0.5%, respectively. Also the reproducibility of CT measurements is good; a disadvantage is the amount of radiation. In this study the diagnostic CT scans in the work - up of (colorectal) cancer were used. This implied no extra radiation. For the purpose of segmentation alone, a low dose protocol can be applied. Obesity is a well known risk factor for complications in and after surgery. Body Mass Index (BMI) is a widely accepted indicator of obesity, but it is not specific for risk assessment of colorectal surgery. We report on an automated method to quantify visceral and subcutaneous adipose tissue volumes as a basic step in a clinical research project concerning preoperative risk assessment. The outcomes are to be correlated with the surgery results. The hypothesis is that the balance between visceral and subcutaneous adipose tissue together with the presence of calcifications in the major bloodvessels, is a predictive indicator for post - operatieve complications such as anastomotic leak. We start with four different computer simulated humanoid abdominal volumes with tissue values in the appropriate Hounsfield range at different dose levels. With satisfactory numerical results for this test, we have applied the algorithm on over a 100 patient scans and have compared results with manual segmentations by an expert for a smaller pilot group. The results are within a 5% difference. Compared to other studies reported in the literature, reliable values are obtained for visceral and subcutaneous adipose tissue areas.

  13. ANATOMICAL VARIATIONS IN SINONASAL REGION IN CASES OF SINUS HEADACHE - CT SCAN - PNS STUDY

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2015-08-01

    Full Text Available BACKGROUND: Sinus headache secondary to Chronic Rhinosinusitis refers to episode of pain over the sinus area of the face and is often associated with nasal congestion, rhinorrhea, facial pressure, lacrimation, nausea and sensory sensitivity. Any small lesions or anatomical variations over lateral wall of nose may giv e rise to sinus headache. CT scan play a vital role in accurate assessment of osteomeatal complex area and anatomical variations at this site. AIM: To study anatomical variations of osteomeatal complex area and deviated septum in cases of chronic sinus hea dache secondary to Chronic Rhinosinusitis. MATERIALS AND METHODS : This study was conducted in Jhalawar Medical College, ENT Department between Sept. 2012 to Dec. 2014. In this study 75 patients withchronic sinus headache was selected who had chronic headac he for more than 3 months duration not responding to medical line of treatment and who were willing to undergo function endoscopic sinus surgery. All patients underwent for CT scan para nasal sinus. RESULT: In this study deviated nasal septum was found in 77.33% patients, apart from that it was observed that 54.66% of the sinus headache cases had two or more anatomical variations and 28% had single anatomical variations, out of them commonest finding is concha bullosa followed by enlarge bulla ethmoid, para doxical middle turbinate, medialiseduncinate process, lateraliseduncinate process, prominent aggar nasi cells, haller cells and onodi cells in decreasing order . CONCLUSION: The study of CT scan PNS conclude that Deviated Nasal Septum and anatomical variati ons at lateral wall of nose causes narrowing of osteomeatal complex area which predisposed patients to sino nasal disease and sinus headache

  14. CT scan-based modelling of anastomotic leak risk after colorectal surgery.

    Science.gov (United States)

    Gervaz, P; Platon, A; Buchs, N C; Rocher, T; Perneger, T; Poletti, P-A

    2013-01-01

    Prolonged ileus, low-grade fever and abdominal discomfort are common during the first week after colonic resection. Undiagnosed anastomotic leak carries a poor outcome and computed tomography (CT) scan is the best imaging tool for assessing postoperative abdominal complications. We used a CT scan-based model to quantify the risk of anastomotic leak after colorectal surgery. A case-control analysis of 74 patients who underwent clinico-radiological evaluation after colorectal surgery for suspicion of anastomotic leak was undertaken and a multivariable analysis of risk factors for leak was performed. A logistic regression model was used to identify determinant variables and construct a predictive score. Out of 74 patients with a clinical suspicion of anastomotic leak, 17 (23%) had this complication confirmed following repeat laparotomy. In multivariate analysis, three variables were associated with anastomotic leak: (1) white blood cells count > 9 × 10(9) /l (OR = 14.8); (2) presence of ≥ 500 cm(3) of intra- abdominal fluid (OR = 13.4); and (3) pneumoperitoneum at the site of anastomosis (OR = 9.9). Each of these three parameters contributed one point to the risk score. The observed risk of leak was 0, 6, 31 and 100%, respectively, for patients with scores of 0, 1, 2 and 3. The area under the receiver operating characteristic curve for the score was 0.83 (0.72-0.94). This CT scan-based model seems clinically promising for objective quantification of the risk of a leak after colorectal surgery. Colorectal Disease © 2013 The Association of Coloproctology of Great Britain and Ireland.

  15. A longitudinal study of neurocysticercosis through CT scan of the brain

    Directory of Open Access Journals (Sweden)

    Abhiram Chakraborty

    2011-09-01

    Full Text Available Objective: To find out the role of CT scan in the diagnosis of neurocysticercosis (NC and also to get an idea of the nature and extent of this disease in a definite geographical ethnic location. Methods: CT scan of the brain of altogether 4 762 persons residing in a congested area of central Kolkata, was performed between 2004 and 2010, in an imaging centre in central Kolkata (Calcutta, of whom 1 114 (23.39% suspected patients were investigated for NC, having complaints of convulsion (472, headache (272, right sided weakness (98, loss of consciousness (84, left sided weakness (61, abnormal behavior (48, slurring of speech (34, difficulty with keeping balance (33 and dementia (12. Results: NC was detected in 45, 1, 0, 2, 1, 0, 0, 1 and 0, respectively consisting 4.48% (50/1 114 of the suspected cases varying from as low as 2 (in 2006 to as high as 23 (in 2005 in different years indicating this parasitic infection is perennial. The age of patients varied from 6 to 59 years of whom 28 (56% were vegan. We were also able to detect 4 types of lesions viz. calcified lesions (14, small hypodense i.e. vesicle (12, bright central spot i.e. vesicular lesion with central spot (2 and ring enhancement (22. For 3 patients, further imaging investigation (MRI was needed to confirm the diagnosis. We calculated the specificity and sensitivity of CT scan of brain diagnosing NC which was found to be 64% and 100%, respectively. Conclusions: Although, the sample may not be the representatives of the whole community, the findings suggest that cysticercosis is a significant but under-recognized public health concern in Kolkata.

  16. Anatomic Variation of Sphenoid Sinus and Related Structures in Libyan Population: CT Scan Study

    Directory of Open Access Journals (Sweden)

    Hewaidi GH

    2008-01-01

    Full Text Available Background: Sphenoid sinus is the most inaccessible paranasal sinus, enclosed within the sphenoid bone and intimately related to numerous vital neural and vascular structures. Anatomic variation of the sphenoid sinus is well documented and may complicate surgery in such a place. Objective: To outline the surgically risky anatomic variants of the sphenoid sinus as well as the variable relationships between the sinus and related neurovascular structures, for the safe removal of intrasphenoid and pituitary lesions. Materials and Methods: We undertook a prospective review of 300 paranasal sinus CT scans of Libyan patients; coronal CT scans were obtained by special parameter techniques. We assessed pneumatization of pterygoid process (PP, anterior clinoid process (ACP, and greater wing of sphenoid (GWS; we also examined protrusion and dehiscence of internal carotid artery (ICA, optic nerve (ON, maxillary nerve (MN, and vidian nerve (VN into the sphenoid sinus cavity. Results: Pneumatization of PP, ACP, and GWS were seen in 87 (29%, 46 (15.3%, and 60 patients (20%, respectively. Protrusion of ICA, ON, MN, and VN were noticed in 123 (41%, 107 (35.6%, 73 (24.3%, and 81 patients (27%, respectively; dehiscence of these structures was encountered in 90 (30%, 92 (30.6%, 39 (13%, and 111 patients (37%, respectively. Statistically, there was a highly significant association between ACP pneumatization and ICA protrusion, ACP pneumatization and ON protrusion, PP pneumatization and VN protrusion; and GWS pneumatization and MN protrusion (p-value < 0.001. Conclusion: The sphenoid sinus is highly variable; this variability necessitates a comprehensive understanding of the regional sphenoid sinus anatomy by a detailed CT scan sinus examination before surgery in and around the sinus. This study indicates the possibility of a racial anatomical variation of the sphenoid sinus in the Libyan population.

  17. High Dose MicroCT Does Not Contribute Toward Improved MicroPET/CT Image Quantitative Accuracy and Can Limit Longitudinal Scanning of Small Animals

    Directory of Open Access Journals (Sweden)

    Wendy A. McDougald

    2017-10-01

    Full Text Available Obtaining accurate quantitative measurements in preclinical Positron Emission Tomography/Computed Tomography (PET/CT imaging is of paramount importance in biomedical research and helps supporting efficient translation of preclinical results to the clinic. The purpose of this study was two-fold: (1 to investigate the effects of different CT acquisition protocols on PET/CT image quality and data quantification; and (2 to evaluate the absorbed dose associated with varying CT parameters.Methods: An air/water quality control CT phantom, tissue equivalent material phantom, an in-house 3D printed phantom and an image quality PET/CT phantom were imaged using a Mediso nanoPET/CT scanner. Collected data was analyzed using PMOD software, VivoQuant software and National Electric Manufactures Association (NEMA software implemented by Mediso. Measured Hounsfield Unit (HU in collected CT images were compared to the known HU values and image noise was quantified. PET recovery coefficients (RC, uniformity and quantitative bias were also measured.Results: Only less than 2 and 1% of CT acquisition protocols yielded water HU values < −80 and air HU values < −840, respectively. Four out of 11 CT protocols resulted in more than 100 mGy absorbed dose. Different CT protocols did not impact PET uniformity and RC, and resulted in <4% overall bias relative to expected radioactive concentration.Conclusion: Preclinical CT protocols with increased exposure times can result in high absorbed doses to the small animals. These should be avoided, as they do not contributed toward improved microPET/CT image quantitative accuracy and could limit longitudinal scanning of small animals.

  18. CT Scan and Pulmonary Sequestration%CT扫描与肺隔离症

    Institute of Scientific and Technical Information of China (English)

    刘秀梅

    2015-01-01

    目的:分析CT增强扫描对肺隔离症的价值。方法回顾性分析经手术病理证实的17例肺隔离症患者。结果手术病理证实2例为叶外型,15例为叶内型,均位于两肺下叶。呈实性肿块的4例,呈囊性的5例(其中2例可见气液平面),呈囊实性肿块的7例。CT增强扫描均可见异常的供血动脉。结论 CT增强扫描清晰显示肺隔离症的异常体动脉血供,在鉴别诊断中具有重大价值。%Objective To analyse the value of constrast-enhanced Routine CT in pulmonary sequestration.Methods The contrast-enhanced Routine CT of 17 patients of pulmonary sequestration were retrospectively studied. They were al proved by surgery.Results There were 2 extra-lober sequestration and 15 intra-lober sequestration in the 17 patients. The lesions of the17 cases located in both lower lobar. 4 of them were solid and 5 were cystic,(2 of 5 cases had air fluid level.),and 7 were cystic and soild.contrast-enhanced Routine CT successfuly delineated abnormal systemic artery.Conclusion Contrast-enhanced Routine CT scan display abnormal systemic artery. Contrast-enhanced Routine CT have important evalution in the distinguish of pulmonary sequestration.

  19. Clinical manifestations that predict abnormal brain computed tomography (CT in children with minor head injury

    Directory of Open Access Journals (Sweden)

    Nesrin Alharthy

    2015-01-01

    Full Text Available Background: Computed tomography (CT used in pediatric pediatrics brain injury (TBI to ascertain neurological manifestations. Nevertheless, this practice is associated with adverse effects. Reports in the literature suggest incidents of morbidity and mortality in children due to exposure to radiation. Hence, it is found imperative to search for a reliable alternative. Objectives: The aim of this study is to find a reliable clinical alternative to detect an intracranial injury without resorting to the CT. Materials and Methods: Retrospective cross-sectional study was undertaken in patients (1-14 years with blunt head injury and having a Glasgow Coma Scale (GCS of 13-15 who had CT performed on them. Using statistical analysis, the correlation between clinical examination and positive CT manifestation is analyzed for different age-groups and various mechanisms of injury. Results: No statistically significant association between parameteres such as Loss of Consciousness, ′fall′ as mechanism of injury, motor vehicle accidents (MVA, more than two discrete episodes of vomiting and the CT finding of intracranial injury could be noted. Analyzed data have led to believe that GCS of 13 at presentation is the only important clinical predictor of intracranial injury. Conclusion: Retrospective data, small sample size and limited number of factors for assessing clinical manifestation might present constraints on the predictive rule that was derived from this review. Such limitations notwithstanding, the decision to determine which patients should undergo neuroimaging is encouraged to be based on clinical judgments. Further analysis with higher sample sizes may be required to authenticate and validate findings.

  20. Interapophyseal joint synovial cyst of lumbar spine. CT scan and MR imaging correlation in two cases

    Energy Technology Data Exchange (ETDEWEB)

    Granat, O.; Jeanbourquin,D.; Perfettini, C.; Pernot, P.; Ducolombier, A.; Cosnard, G.

    1987-05-01

    Two patients presenting with L5 radiculagia were investigated by CT scan imaging. The origin of the pain was determined with certitude as arising from intraspinal development of an interapophyseal synovial cyst. Examination of the two cases by MR imaging provided conflicting results: in one patient images obtained by MR were not contributive and the synovial cyst would probably have been missed while in the other patient images were specific and very sensitive for diagnosis of interapophyseal synovial lesions. Treatment was surgical in both cases.

  1. Image reconstruction for view-limited x-ray CT in baggage scanning

    Science.gov (United States)

    Mandava, Sagar; Coccarelli, David; Greenberg, Joel A.; Gehm, Michael E.; Ashok, Amit; Bilgin, Ali

    2017-05-01

    X-ray CT based baggage scanners are widely used in security applications. Recently, there has been increased interest in view-limited systems which can improve the scanning throughput while maintaining the threat detection performance. However as very few view angles are acquired in these systems, the image reconstruction problem is challenging. Standard reconstruction algorithms such as the filtered backprojection create strong artifacts when working with view-limited data. In this work, we study the performance of a variety of reconstruction algorithms for both single and multi-energy view-limited systems.

  2. CT scans of Sts 14 provide the potential for manufacturing casts

    CSIR Research Space (South Africa)

    Kirkbride, AN

    1997-04-01

    Full Text Available : To place article links in an external web document, simply copy and paste the HTML below, starting with "CT scans for Sts 14 provide the potential for manufacturing casts. Authors: Yates, Simon C. Kirkbride, Anthony N. Source...

  3. Evaluating soft tissue simulation in maxillofacial surgery using pre and post-operative CT scan

    CERN Document Server

    Chabanas, M; Chouly, F; Boutault, F; Payan, Y; Chabanas, Matthieu; Marecaux, Christophe; Chouly, Franz; Boutault, Franck; Payan, Yohan

    2004-01-01

    One of the most important issue in soft tissue modeling is to assess the quality of the simulations. A validation protocol is presented based on two CT scans of the patient acquired before and after cranio-maxillofacial surgery. The actual bones repositioning realized during the intervention are accurately measured and reproduced. A evaluation of the soft tissue deformation is then computed using a finite element model of the face. The simulations are therefore compared, qualitatively and quantitatively, with the actual outcome of the surgery. This protocol enable to rigorously evaluate different modeling methods, and to assess the clinical relevance of soft tissue simulation in maxillofacial surgery.

  4. 18F-FDG PET/CT Scan Can Predate Clinical Presentation in Acute Appendicitis.

    Science.gov (United States)

    Ali, Syed Zama; Yin, Loi Hoi; Kin, Khor Lih; Sinha, Arvind Kumar; Poon, Li Mei

    2017-09-01

    Acute appendicitis is a clinical diagnosis typically presenting with right lower quadrant pain. We describe the case of an asymptomatic 53-year-old man with stage 2A diffuse large B-cell lymphoma, who underwent F-FDG PET/CT at the completion of chemotherapy. The scan showed complete lymphomatous disease remission. Incidentally, there was increased FDG uptake in a tubular structure adjacent to the cecum. Clinical examination was negative. Subsequently, the patient presented 6 days later with typical acute appendicitis symptoms. This case is interesting wherein increased FDG uptake in the appendix predated the appearance of clinical symptoms.

  5. SU-E-J-219: A Dixon Based Pseudo-CT Generation Method for MR-Only Radiotherapy Treatment Planning of the Pelvis and Head and Neck

    Energy Technology Data Exchange (ETDEWEB)

    Maspero, M.; Meijer, G.J.; Lagendijk, J.J.W.; Berg, C.A.T. van den [Department of Radiotherapy, UMC Utrecht (Netherlands); Seevinck, P.R.; Viergever, M.A. [Image Science Institute, UMC Utrecht (Netherlands)

    2015-06-15

    Purpose: To develop an image processing method for MRI-based generation of electron density maps, known as pseudo-CT (pCT), without usage of model- or atlas-based segmentation, and to evaluate the method in the pelvic and head-neck region against CT. Methods: CT and MRI scans were obtained from the pelvic region of four patients in supine position using a flat table top only for CT. Stratified CT maps were generated by classifying each voxel based on HU ranges into one of four classes: air, adipose tissue, soft tissue or bone.A hierarchical region-selective algorithm, based on automatic thresholding and clustering, was used to classify tissues from MR Dixon reconstructed fat, In-Phase (IP) and Opposed-Phase (OP) images. First, a body mask was obtained by thresholding the IP image. Subsequently, an automatic threshold on the Dixon fat image differentiated soft and adipose tissue. K-means clustering on IP and OP images resulted in a mask that, via a connected neighborhood analysis, allowing the user to select the components corresponding to bone structures.The pCT was estimated through assignment of bulk HU to the tissue classes. Bone-only Digital Reconstructed Radiographs (DRR) were generated as well. The pCT images were rigidly registered to the stratified CT to allow a volumetric and voxelwise comparison. Moreover, pCTs were also calculated within the head-neck region in two volunteers using the same pipeline. Results: The volumetric comparison resulted in differences <1% for each tissue class. A voxelwise comparison showed a good classification, ranging from 64% to 98%. The primary misclassified classes were adipose/soft tissue and bone/soft tissue. As the patients have been imaged on different table tops, part of the misclassification error can be explained by misregistration. Conclusion: The proposed approach does not rely on an anatomy model providing the flexibility to successfully generate the pCT in two different body sites. This research is founded by Zon

  6. Head and neck squamous cell carcinoma (HNSCC) - detection of synchronous primaries with {sup 18}F-FDG-PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, Klaus; Schrank, Madeleine; Soyka, Jan D.; Veit-Haibach, Patrick; Hany, Thomas F. [University Hospital Zurich, Division of Nuclear Medicine, Department of Medical Radiology, Zurich (Switzerland); Haerle, Stephan K.; Stoeckli, Sandro J. [University Hospital Zurich, Department of Otorhinolaryngology, Head and Neck Surgery, Zurich (Switzerland)

    2009-06-15

    The aim of the study was to evaluate {sup 18}F-FDG-PET/CT for the detection of synchronous primaries at initial staging of patients with head and neck squamous cell carcinoma (HNSCC). FDG-PET/CT images acquired between March 2001 and October 2007 in 589 consecutive patients (147 women, 442 men; mean age 61.5 years, age range 32-97 years) with proven HNSCC were reviewed for the presence of synchronous primaries. Cytology, histology and/or clinical and imaging follow-up served as reference standard. FDG-PET/CT showed 69 suspected synchronous primaries in 62 patients of which 56 were finally confirmed in 44 patients. Of the 56 second cancers, 46 (82%) were found in the aerodigestive tract in the following locations: lung (26, 46%), head and neck (15, 17%), oesophagus (5, 9%). Ten second cancers (18%) were located outside the aerodigestive tract (colon, five; stomach, lymphoma, breast, thymus and kidney, one each). Six patients had three synchronous primaries and three patients had four synchronous cancers. Nine synchronous cancers were not detected by PET/CT (four head and neck, two lung, two oesophageal, one gastric). False-positive PET/CT findings were mainly related to benign FDG uptake in the intestine due to benign or precancerous polyps or physiological FDG uptake in other head and neck regions. Overall the prevalence of synchronous second primaries according to the reference standard was 9.5%, of which 84% were detected with FDG-PET/CT. In 80% of the patients, therapy was changed because of the detection of a synchronous primary. FDG-PET/CT detects a considerable number of synchronous primaries (8.0% prevalence) at initial staging of patients with HNSCC. Synchronous cancers were predominantly located in the aerodigestive tract, primarily in the lung, head and neck and oesophagus. Detection of second primaries has an important impact on therapy. PET/CT should be performed before panendoscopy. (orig.)

  7. Perfusion CT of head and neck cancer: effect of arterial input selection.

    Science.gov (United States)

    Tawfik, Ahmed M; Razek, Ahmed A Abdel; Elsorogy, Lamiaa G; Soliman, Nermin Y; Kerl, J Matthias; Mack, Martin G; Vogl, Thomas J

    2011-06-01

    The purpose of this study is to evaluate the effect of arterial input selection on perfusion CT parameters of head and neck tumors. Perfusion calculations were done for 50 cases using deconvolution-based software. Peak enhancement values of the ipsilateral internal carotid artery (ICA) and external carotid artery (ECA) were recorded. Blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface area product were calculated using ipsilateral ECA, ipsilateral ICA, and contralateral ICA as input arteries. Values were compared using Wilcoxon's matched pair test and Pearson's correlation coefficients (r). A highly significant correlation was observed between peak enhancement values of the ICA and ECA (r = 0.97; p 0.05). Arterial input selection has no significant effect on perfusion CT calculation of head and neck cancer. For standardization and simplification of postprocessing, we recommend the use of the ICA instead of the ECA as the arterial input because of its better visualization, perpendicular course, and larger caliber, all of which decrease partial volume effects.

  8. The pros and cons of intraoperative CT scan in evaluation of deep brain stimulation lead implantation: A retrospective study

    Science.gov (United States)

    Servello, Domenico; Zekaj, Edvin; Saleh, Christian; Pacchetti, Claudio; Porta, Mauro

    2016-01-01

    Background: Deep brain stimulation (DBS) is an established therapy for movement disorders, such as Parkinson's disease (PD), dystonia, and tremor. The efficacy of DBS depends on the correct lead positioning. The commonly adopted postoperative radiological evaluation is performed with computed tomography (CT) scan and/or magnetic resonance imaging (MRI). Methods: We conducted a retrospective study on 202 patients who underwent DBS from January 2009 to October 2013. DBS indications were PD, progressive supranuclear palsy, tremor, dystonia, Tourette syndrome, obsessive compulsive disorder, depression, and Huntington's disease. Preoperatively, all patients underwent brain MRI and brain CT scan with the stereotactic frame positioned. The lead location was confirmed intraoperatively with CT. The CT images were subsequently transferred to the Stealth Station Medtronic and merged with the preoperative planning. On the first or second day after, implantation we performed a brain MRI to confirm the correct position of the lead. Results: In 14 patients, leads were in suboptimal position after intraoperative CT scan positioning. The cases with alteration in the Z-axis were corrected immediately under fluoroscopic guidance. In all the 14 patients, an immediate repositioning was done. Conclusions: Based on our data, intraoperative CT scan is fast, safe, and a useful tool in the evaluation of the position of the implanted lead. It also reduces the patient's discomfort derived from the transfer of the patient from the operating room to the radiological department. However, intraoperative CT should not be considered as a substitute for postoperative MRI. PMID:27583182

  9. Clinical significance of multislice spiral CT scans in hepatic veins occlusion in Budd-Chiari syndrome

    Institute of Scientific and Technical Information of China (English)

    MENG Xiao-chun; ZHU Kang-shun; QIN Jie; ZHANG Jian-sheng; WANG Xiao-hong; ZOU Yan; ZHANG Ya-qin; SHAN Hong

    2007-01-01

    Background Budd-Chiari syndrome with hepatic vein occlusion (HVBCS) can induce severe portal hypertension and liver damage. We retrospectively analyzed hepatic CT features of HVBCS and evaluated the usefulness of triphasic enhancement of CT examinations and CT angiography (CTA) in its diagnosis.Methods Twenty-five cases with HVBCS, confirmed by digital subtraction angiography (DSA), received a triphasic enhancement CT scan within one week before DSA. The CTA images of the relevant blood vessels were reconstructed with maximum intensity projection, volume rendering and oblique reformat techniques.Results Compared with DSA, the detection rate of transverse CT and CTA images for abnormal hepatic vein were 81.7% (58/71) and 95.8% (68/71) (χ2=7.044, P=0.008), for membranous obstruction were 47.4% (9/19) and 84.2% (16/19) respectively (χ2 =5.729, P=0.017 ), for segmental obstruction were 88.0% (22/25) and 100% (25/25) respectively (χ2=1.418, P=0.234). The detection rates for hepatic vein stenosis were 100% with each method. Diffuse hepatomegaly was found in all 6 cases in acute phase and 3 of 19 cases in chronic phase who had severe obstruction of three hepatic veins without patent intrahepatic collaterals. The other 16 cases in chronic phase had hepatatrophia to different extents related to the obstructed hepatic vein. All in acute phase and 15 in chronic phase presented typical patchy enhancement initially in caudate lobe and perihilar areas and enlarged with time delay. In all cases, parenchyma areas with atrophy, necrosis and congestion demonstrated lower and later enhancement. In all the parts, which had normal enhancement at least one patent outflow hepatic vein, accessory hepatic vein or collateral vessel was detected. Conclusion Dynamic enhancement CT examination by multislice spiral CT not only could improve the diagnosis of HVBCS by CTA technique, but also could noninvasively provide anatomical information and reveal damage to the hepatic parenchyma.

  10. Adapted Treatment Guided by Interim PET-CT Scan in Advanced Hodgkin's Lymphoma.

    Science.gov (United States)

    Johnson, Peter; Federico, Massimo; Kirkwood, Amy; Fosså, Alexander; Berkahn, Leanne; Carella, Angelo; d'Amore, Francesco; Enblad, Gunilla; Franceschetto, Antonella; Fulham, Michael; Luminari, Stefano; O'Doherty, Michael; Patrick, Pip; Roberts, Thomas; Sidra, Gamal; Stevens, Lindsey; Smith, Paul; Trotman, Judith; Viney, Zaid; Radford, John; Barrington, Sally

    2016-06-23

    We tested interim positron-emission tomography-computed tomography (PET-CT) as a measure of early response to chemotherapy in order to guide treatment for patients with advanced Hodgkin's lymphoma. Patients with newly diagnosed advanced classic Hodgkin's lymphoma underwent a baseline PET-CT scan, received two cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapy, and then underwent an interim PET-CT scan. Images were centrally reviewed with the use of a 5-point scale for PET findings. Patients with negative PET findings after two cycles were randomly assigned to continue ABVD (ABVD group) or omit bleomycin (AVD group) in cycles 3 through 6. Those with positive PET findings after two cycles received BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone). Radiotherapy was not recommended for patients with negative findings on interim scans. The primary outcome was the difference in the 3-year progression-free survival rate between randomized groups, a noninferiority comparison to exclude a difference of 5 or more percentage points. A total of 1214 patients were registered; 937 of the 1119 patients (83.7%) who underwent an interim PET-CT scan according to protocol had negative findings. With a median follow-up of 41 months, the 3-year progression-free survival rate and overall survival rate in the ABVD group were 85.7% (95% confidence interval [CI], 82.1 to 88.6) and 97.2% (95% CI, 95.1 to 98.4), respectively; the corresponding rates in the AVD group were 84.4% (95% CI, 80.7 to 87.5) and 97.6% (95% CI, 95.6 to 98.7). The absolute difference in the 3-year progression-free survival rate (ABVD minus AVD) was 1.6 percentage points (95% CI, -3.2 to 5.3). Respiratory adverse events were more severe in the ABVD group than in the AVD group. BEACOPP was given to the 172 patients with positive findings on the interim scan, and 74.4% had negative findings on a third PET-CT scan; the 3-year progression

  11. Adapted Treatment Guided by Interim PET-CT Scan in Advanced Hodgkin’s Lymphoma

    Science.gov (United States)

    Johnson, Peter; Federico, Massimo; Kirkwood, Amy; Fosså, Alexander; Berkahn, Leanne; Carella, Angelo; d’Amore, Francesco; Enblad, Gunilla; Franceschetto, Antonella; Fulham, Michael; Luminari, Stefano; O’Doherty, Michael; Patrick, Pip; Roberts, Thomas; Sidra, Gamal; Stevens, Lindsey; Smith, Paul; Trotman, Judith; Viney, Zaid; Radford, John; Barrington, Sally

    2016-01-01

    Background We tested interim positron-emission tomography–computed tomography (PET-CT) as a measure of early response to chemotherapy in order to guide treatment for patients with advanced Hodgkin’s lymphoma. Methods Patients with newly diagnosed advanced classic Hodgkin’s lymphoma underwent a baseline PET-CT scan, received two cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapy, and then underwent an interim PET-CT scan. Images were centrally reviewed with the use of a 5-point scale for PET findings. Patients with negative PET findings after two cycles were randomly assigned to continue ABVD (ABVD group) or omit bleomycin (AVD group) in cycles 3 through 6. Those with positive PET findings after two cycles received BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone). Radiotherapy was not recommended for patients with negative findings on interim scans. The primary outcome was the difference in the 3-year progression-free survival rate between randomized groups, a noninferiority comparison to exclude a difference of 5 or more percentage points. Results A total of 1214 patients were registered; 937 of the 1119 patients (83.7%) who underwent an interim PET-CT scan according to protocol had negative findings. With a median follow-up of 41 months, the 3-year progression-free survival rate and overall survival rate in the ABVD group were 85.7% (95% confidence interval [CI], 82.1 to 88.6) and 97.2% (95% CI, 95.1 to 98.4), respectively; the corresponding rates in the AVD group were 84.4% (95% CI, 80.7 to 87.5) and 97.6% (95% CI, 95.6 to 98.7). The absolute difference in the 3-year progression-free survival rate (ABVD minus AVD) was 1.6 percentage points (95% CI, −3.2 to 5.3). Respiratory adverse events were more severe in the ABVD group than in the AVD group. BEACOPP was given to the 172 patients with positive findings on the interim scan, and 74.4% had negative findings on a third

  12. CT synthesis in the head & neck region for PET/MR attenuation correction: an iterative multi-atlas approach

    Energy Technology Data Exchange (ETDEWEB)

    Burgos, Ninon [Translational Imaging Group, Centre for Medical Image Computing, University College London, London (United Kingdom); Cardoso, M Jorge; Modat, Marc [Translational Imaging Group, Centre for Medical Image Computing, University College London, London (United Kingdom); Dementia Research Centre, University College London, London (United Kingdom); Punwani, Shonit [Division of Imaging, University College London Hospitals, London (United Kingdom); Centre for Medical Imaging, University College London, London (United Kingdom); Atkinson, David [Centre for Medical Imaging, University College London, London (United Kingdom); Arridge, Simon R [Centre for Medical Image Computing, University College London, London (United Kingdom); Hutton, Brian F [Institute of Nuclear Medicine, University College London Hospitals, London (United Kingdom); Ourselin, Sébastien [Translational Imaging Group, Centre for Medical Image Computing, University College London, London (United Kingdom); Dementia Research Centre, University College London, London (United Kingdom)

    2015-05-18

    In this work, we propose to tackle the problem of attenuation correction in the head and neck by synthesising CT from MR images using an iterative multi-atlas approach. The proposed method relies on pre-acquired T2-weighted MRI and CT images of the neck. For each subject, the MRI is non-rigidly mapped to the CT. To synthesise a pseudo CT, all the MRIs in the database are first registered to the target MRI. This registration consists of a robust affine followed by a non-rigid registration. The pseudo CT is obtained by fusing the mapped atlases according to their morphological similarity to the target. In contrast to CTs, T2 images do not provide a good estimate of the bone location. Combining multiple modalities at both the registration and image similarity stages is expected to provide more realistic mappings and to reduce the bias. An initial pseudo CT (pCT) is combined with the target MRI to form a MRI-pCT pair. The MRI-pCT pair is registered to all the MRI-CT pairs from the database. An improved pseudo CT is obtained by fusing the mapped MRI-CT pairs according to their morphological similarity to the target MRI-pCT pair. Results showed that the proposed CT synthesis algorithm based on a multi-atlas information propagation scheme and iterative process is able to synthesise pseudo CT images in a region challenging for registration algorithms. The results also demonstrate that the robust affine decreases the absolute error compared to the classic approach and that the bone refinement process reduces the bias in the bone region. The proposed method could be used to correct for attenuation PET/MR data, but also for dosimetry calculations in the context of MR-based radiotherapy treatment planning.

  13. Using the fourth dimension to distinguish between structures for anisotropic diffusion filtering in 4D CT perfusion scans

    NARCIS (Netherlands)

    Mendrik, AM; Vonken, EPA; Witkamp, TD; Prokop, Mathias; Van Ginneken, Bram; Viergever, Max A.

    2015-01-01

    High resolution 4D (3D+time) cerebral CT perfusion (CTP) scans can be used to create 3D arteriograms (showing only arteries) and venograms (only veins). However, due to the low X-ray radiation dose used for acquiring the CTP scans, they are inherently noisy. In this paper, we propose a time intensit

  14. Sensitivity calibration procedures in optical-CT scanning of BANG 3 polymer gel dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y.; Wuu, Cheng-Shie; Maryanski, Marek J. [Department of Radiation Oncology, Columbia University, New York, New York 10032 (United States); Department of Radiation Oncology, Columbia University, New York, New York 10032 and MGS Research Inc., Madison, Connecticut 06443 (United States)

    2010-02-15

    The dose response of the BANG 3 polymer gel dosimeter (MGS Research Inc., Madison, CT) was studied using the OCTOPUS laser CT scanner (MGS Research Inc., Madison, CT). Six 17 cm diameter and 12 cm high Barex cylinders, and 18 small glass vials were used to house the gel. The gel phantoms were irradiated with 6 and 10 MV photons, as well as 12 and 16 MeV electrons using a Varian Clinac 2100EX. Three calibration methods were used to obtain the dose response curves: (a) Optical density measurements on the 18 glass vials irradiated with graded doses from 0 to 4 Gy using 6 or 10 MV large field irradiations; (b) optical-CT scanning of Barex cylinders irradiated with graded doses (0.5, 1, 1.5, and 2 Gy) from four adjacent 4x4 cm{sup 2} photon fields or 6x6 cm{sup 2} electron fields; and (c) percent depth dose (PDD) comparison of optical-CT scans with ion chamber measurements for 6x6 cm{sup 2}, 12 and 16 MeV electron fields. The dose response of the BANG 3 gel was found to be linear and energy independent within the uncertainties of the experimental methods (about 3%). The slopes of the linearly fitted dose response curves (dose sensitivities) from the four field irradiations (0.0752{+-}3%, 0.0756{+-}3%, 0.0767{+-}3%, and 0.0759{+-}3% cm{sup -1} Gy{sup -1}) and the PDD matching methods (0.0768{+-}3% and 0.0761{+-}3% cm{sup -1} Gy{sup -1}) agree within 2.2%, indicating a good reproducibility of the gel dose response within phantoms of the same geometry. The dose sensitivities from the glass vial approach are different from those of the cylindrical Barex phantoms by more than 30%, owing probably to the difference in temperature inside the two types of phantoms during gel formation and irradiation, and possible oxygen contamination of the glass vial walls. The dose response curve obtained from the PDD matching approach with 16 MeV electron field was used to calibrate the gel phantom irradiated with the 12 MeV, 6x6 cm{sup 2} electron field. Three-dimensional dose distributions

  15. Risk stratification of non-contrast CT beyond the coronary calcium scan.

    Science.gov (United States)

    Madaj, Paul; Budoff, Matthew J

    2012-01-01

    Coronary artery calcification (CAC) is a well-known marker for coronary artery disease and has important prognostic implications. CAC is able to provide clinicians with a reliable source of information related to cardiovascular atherosclerosis, which carries incremental information beyond Framingham risk. However, non-contrast scans of the heart provide additional information beyond the Agatston score. These studies are also able to measure various sources of fat, including intrathoracic (eg, pericardial or epicardial) and hepatic, both of which are thought to be metabolically active and linked to increased incidence of subclinical atherosclerosis as well as increased prevalence of type 2  diabetes. Testing for CAC is also useful in identifying extracoronary sources of calcification. Specifically, aortic valve calcification, mitral annular calcification, and thoracic aortic calcium (TAC) provide additional risk stratification information for cardiovascular events. Finally, scanning for CAC is able to evaluate myocardial scaring due to myocardial infarcts, which may also add incremental prognostic information. To ensure the benefits outweigh the risks of a scanning for CAC for an appropriately selected asymptomatic patient, the full utility of the scan should be realized. This review describes the current state of the art interpretation of non-contrast cardiac CT, which clinically should go well beyond coronary artery Agatston scoring alone.

  16. Angiogenesis in tissue-engineered nerves evaluated objectively using MICROFIL perfusion and micro-CT scanning

    Institute of Scientific and Technical Information of China (English)

    Hong-kui Wang; Ya-xian Wang; Cheng-bin Xue; Zhen-mei-yu Li; Jing Huang; Ya-hong Zhao; Yu-min Yang; Xiao-song Gu

    2016-01-01

    Angiogenesis is a key process in regenerative medicine generally, as well as in the speciifc ifeld of nerve regeneration. However, no conve-nient and objective method for evaluating the angiogenesis of tissue-engineered nerves has been reported. In this study, tissue-engineered nerves were constructedin vitro using Schwann cells differentiated from rat skin-derived precursors as supporting cells and chitosan nerve conduits combined with silk ifbroin ifbers as scaffolds to bridge 10-mm sciatic nerve defects in rats. Four weeks after surgery, three-di-mensional blood vessel reconstructions were made through MICROFIL perfusion and micro-CT scanning, and parameter analysis of the tissue-engineered nerves was performed. New blood vessels grew into the tissue-engineered nerves from three main directions: the prox-imal end, the distal end, and the middle. The parameter analysis of the three-dimensional blood vessel images yielded several parameters, including the number, diameter, connection, and spatial distribution of blood vessels. The new blood vessels were mainly capillaries and microvessels, with diameters ranging from 9 to 301µm. The blood vessels with diameters from 27 to 155µm accounted for 82.84% of the new vessels. The microvessels in the tissue-engineered nerves implantedin vivo were relatively well-identiifed using the MICROFIL perfusion and micro-CT scanning method, which allows the evaluation and comparison of differences and changes of angiogenesis in tis-sue-engineered nerves implantedin vivo.

  17. Evaluating 3D registration of CT-scan images using crest lines

    Science.gov (United States)

    Ayache, Nicholas; Gueziec, Andre P.; Thirion, Jean-Philippe; Gourdon, A.; Knoplioch, Jerome

    1993-06-01

    We consider the issue of matching 3D objects extracted from medical images. We show that crest lines computed on the object surfaces correspond to meaningful anatomical features, and that they are stable with respect to rigid transformations. We present the current chain of algorithmic modules which automatically extract the major crest lines in 3D CT-Scan images, and then use differential invariants on these lines to register together the 3D images with a high precision. The extraction of the crest lines is done by computing up to third order derivatives of the image intensity function with appropriate 3D filtering of the volumetric images, and by the 'marching lines' algorithm. The recovered lines are then approximated by splines curves, to compute at each point a number of differential invariants. Matching is finally performed by a new geometric hashing method. The whole chain is now completely automatic, and provides extremely robust and accurate results, even in the presence of severe occlusions. In this paper, we briefly describe the whole chain of processes, already presented to evaluate the accuracy of the approach on a couple of CT-scan images of a skull containing external markers.

  18. Comparative analysis of realistic CT-scan and simplified human airway models in airflow simulation.

    Science.gov (United States)

    Johari, Nasrul Hadi; Osman, Kahar; Helmi, Nor Harris N; Abdul Kadir, Mohammed A Rafiq

    2015-01-01

    Efforts to model the human upper respiratory system have undergone many phases. Geometrical proximity to the realistic shape has been the subject of many research projects. In this study, three different geometries of the trachea and main bronchus were modelled, which were reconstructed from computed tomography (CT) scan images. The geometrical variations were named realistic, simplified and oversimplified. Realistic refers to the lifelike image taken from digital imaging and communications in medicine format CT scan images, simplified refers to the reconstructed image based on natural images without realistic details pertaining to the rough surfaces, and oversimplified describes the straight wall geometry of the airway. The characteristics of steady state flows with different flow rates were investigated, simulating three varied physical activities and passing through each model. The results agree with previous studies where simplified models are sufficient for providing comparable results for airflow in human airways. This work further suggests that, under most exercise conditions, the idealised oversimplified model is not favourable for simulating either airflow regimes or airflow with particle depositions. However, in terms of immediate analysis for the prediction of abnormalities of various dimensions of human airways, the oversimplified techniques may be used.

  19. AIDS complicated with intestinal lymphoma: X-ray radiology,CT scan and pathological findings

    Institute of Scientific and Technical Information of China (English)

    LI Hong-jun; CHENG Jing-liang

    2011-01-01

    Background The non-Hodgkin's lymphoma is the AIDS symbol of tumor, with high incidence and poor prognosis. The purpose of this study was to investigate the radiological demonstrations of AIDS complicated by intestinal lymphoma and its pathological mechanism.Methods CT scan and pathological data of 3 cases of AIDS complicated by intestinal lymphoma were retrospectively analyzed. All the 3 cases received CT diagnostic scanning, including 2 receiving barium enema radiography after lower gastrointestinal tract cleansing, 1 receiving laporotomy to obtain partial thickened intestinal canal for histopathology and 1with autopsy for histopathological analysis.Results Intestinal canal lymphoma occurred at the left intestinal canal in 2 cases and at the right intestinal canal in the other case, with manifestations of unevenly thickened intestinal canal wall, narrowed canal lumen and filling defect. It was pathologically classified as B cell lymphoma.Conclusions AIDS complicated by B cell lymphoma has manifestations of unevenly thickened intestinal canal wall and narrowed canal lumen, which are non-specific. It should be differentiated from other tumors of intestinal canal in its diagnosis.

  20. Radiological Appearance of Extrapulmonary Lesions in Rradiography (CT scan-MRI

    Directory of Open Access Journals (Sweden)

    A. Soltani Shirazi

    2005-08-01

    Full Text Available Introduction & Background: To make the diagnosis of chest lesions in chest radiography or CT scan easier, lesions are divided into three main groups: lesions of lung parenchyma, lesions of the heart and mediasti-num and lesions with origins of the protective tissues in the chest. Extrapulmonary lesions have various origins ranging from hard tissues like the bone, to soft tissues such as bone marrow or fatty tissue; they usu-ally present with diverse and sometimes misleading signs and symptoms. Knowledge about the radiologic semiolology of these instances helps to prevent mis-taking these lesions with lesions of pulmonary origin. Consequently timely and appropriate treatment can be provided. Here a study of five thousand chest radi-ographies of extrapulmonary lesions with primary diagnosis of pulmonary lesions is presented and the approach to diagnosis is discussed. According to the present study, 56% of extrapulmonary lesions are de-tectable by means of simple primary radiography and by considering radiologic semiology. We reached definite diagnosis by means of lung CT scan. Other lesions were diagnosed after performing biopsy or surgery.

  1. CT Scan Mapping of Splenic Flexure in Relation to Spleen and its Clinical Implications.

    Science.gov (United States)

    Saber, Alan A; Dervishaj, Ornela; Aida, Samer S; Christos, Paul J; Dakhel, Mahmoud

    2016-05-01

    Splenic flexure mobilization is a challenging step during left colon resection. The maneuver places the spleen at risk for injury. To minimize this risk, we conducted this study for CT scan mapping of splenic flexure in relation to the spleen. One hundred and sixty CT scans of abdomen were reviewed. The level of the splenic flexure was determined in relation to hilum and lower pole of spleen. These levels were compared with patient demographics. Statistical analysis was performed using Fisher's exact test. The splenic flexure was above the hilum of the spleen in 95 patients (67.86%), at the splenic hilum level in 11 patents (7.88%), between the hilum and lower pole of the spleen in 12 (8.57%), at the lower pole of the spleen in 15 (10.7%) patients and 7 (5%) patients has a splenic flexure that lied below the lower pole of the spleen. Patient demographics showed no statistical significance in regard to splenic flexure location. Splenic flexure lies above the hilum of the spleen in majority of patients. This should be considered as part of operative strategies for left colon resection.

  2. CT scan findings in three cases of multiple sclerosis with homonymous hemianopsia

    Energy Technology Data Exchange (ETDEWEB)

    Arikado, Takuji; Ariga, Hiroko; Kase, Manabu; Nagata, Renpei; Tashiro, Kunio (Hokkaido Univ., Sapporo (Japan). School of Medicine)

    1983-11-01

    Three cases of clinically definite multiple sclerosis manifested homonymous hemianopsia. A 35-year-old female, in whom right optic neuritis developed as the initial symptom, manifested right homonymous hemianopsia 4 months later followed by cerebral symptoms another 4 months later. A 25-year-old male developed sudden brain stem and cerebellar symptoms associated with right abducens palsy and right homonymous hemianopsia. In a 26-year-old female developed right homonymous hemianopsia 13 years after the first attack of recurrent optic neuritis. CT-scan in these three cases revealed the presence of a ''plaque'' located in the white matter of the left occipital lobe in cases 1 and 2 and in the left peririgone white matter in case 3 as the causative lesion for the right homonymous hemianopsia. These findings indicate that the optic radiation may be involved in multiple sclerosis resulting in homonymous hemianopsia. CT scan is of value in determining the location of the affected intracranial lesion in multiple sclerosis.

  3. Axial segmentation of lungs CT scan images using canny method and morphological operation

    Science.gov (United States)

    Noviana, Rina; Febriani, Rasal, Isram; Lubis, Eva Utari Cintamurni

    2017-08-01

    Segmentation is a very important topic in digital image process. It is found simply in varied fields of image analysis, particularly within the medical imaging field. Axial segmentation of lungs CT scan is beneficial in designation of abnormalities and surgery planning. It will do to ascertain every section within the lungs. The results of the segmentation are accustomed discover the presence of nodules. The method which utilized in this analysis are image cropping, image binarization, Canny edge detection and morphological operation. Image cropping is done so as to separate the lungs areas, that is the region of interest. Binarization method generates a binary image that has 2 values with grey level, that is black and white (ROI), from another space of lungs CT scan image. Canny method used for the edge detection. Morphological operation is applied to smoothing the lungs edge. The segmentation methodology shows an honest result. It obtains an awfully smooth edge. Moreover, the image background can also be removed in order to get the main focus, the lungs.

  4. Computer-aided detection and quantification of cavitary tuberculosis from CT scans

    Science.gov (United States)

    Xu, Ziyue; Bagci, Ulas; Kubler, Andre; Luna, Brian; Jain, Sanjay; Bishai, William R.; Mollura, Daniel J.

    2013-01-01

    Purpose: To present a computer-aided detection tool for identifying, quantifying, and evaluating tuberculosis (TB) cavities in the infected lungs from computed tomography (CT) scans. Methods: The authors’ proposed method is based on a novel shape-based automated detection algorithm on CT scans followed by a fuzzy connectedness (FC) delineation procedure. In order to assess interaction between cavities and airways, the authors first roughly identified air-filled structures (airway, cavities, esophagus, etc.) by thresholding over Hounsfield unit of CT image. Then, airway and cavity structure detection was conducted within the support vector machine classification algorithm. Once airway and cavities were detected automatically, the authors extracted airway tree using a hybrid multiscale approach based on novel affinity relations within the FC framework and segmented cavities using intensity-based FC algorithm. At final step, the authors refined airway structures within the local regions of FC with finer control. Cavity segmentation results were compared to the reference truths provided by expert radiologists and cavity formation was tracked longitudinally from serial CT scans through shape and volume information automatically determined through the authors’ proposed system. Morphological evolution of the cavitary TB were analyzed accordingly with this process. Finally, the authors computed the minimum distance between cavity surface and nearby airway structures by using the linear time distance transform algorithm to explore potential role of airways in cavity formation and morphological evolution. Results: The proposed methodology was qualitatively and quantitatively evaluated on pulmonary CT images of rabbits experimentally infected with TB, and multiple markers such as cavity volume, cavity surface area, minimum distance from cavity surface to the nearest bronchial-tree, and longitudinal change of these markers (namely, morphological evolution of cavities) were

  5. Time-resolved scanning Kerr microscopy of flux beam formation in hard disk write heads

    Science.gov (United States)

    Valkass, Robert A. J.; Spicer, Timothy M.; Burgos Parra, Erick; Hicken, Robert J.; Bashir, Muhammad A.; Gubbins, Mark A.; Czoschke, Peter J.; Lopusnik, Radek

    2016-06-01

    To meet growing data storage needs, the density of data stored on hard disk drives must increase. In pursuit of this aim, the magnetodynamics of the hard disk write head must be characterized and understood, particularly the process of "flux beaming." In this study, seven different configurations of perpendicular magnetic recording (PMR) write heads were imaged using time-resolved scanning Kerr microscopy, revealing their detailed dynamic magnetic state during the write process. It was found that the precise position and number of driving coils can significantly alter the formation of flux beams during the write process. These results are applicable to the design and understanding of current PMR and next-generation heat-assisted magnetic recording devices, as well as being relevant to other magnetic devices.

  6. Case of asymmetrical arthrogryposis. A clinical study and a preliminary report on the value of CT-scanning

    Energy Technology Data Exchange (ETDEWEB)

    Hageman, G.; Vette, J.K.; Willemse, J. (University Hospital, Utrecht (Netherlands))

    1983-01-01

    Following the introduction of the conception that arthrogryposis is a symptom and not a clinical entity, a case of the very rare asymmetric form of neurogenic arthrogryposis is presented. The asymmetry of congenital contractures and weakness is associated with hemihypotrophy. The value of muscular CT-scanning prior to muscle biopsy is demonstrated. Muscular CT-scanning shows the extension of adipose tissue, which has replaced damaged muscles and therby indicates the exact site for muscle biopsy. Since orthopaedic treatment in arthrogryposis can be unrewarding due to severe muscular degeneration, preoperative scanning may provide additional important information on muscular function and thus be of benefit for surgery. The advantage of muscular CT-scanning in other forms of arthrogryposis requires further determination. The differential diagnosis with Werdnig-Hoffmann disease is discussed.

  7. Intracranial carotid artery calcification on head CT and its association with ischemic changes on brain MRI in patients presenting with stroke-like symptoms: retrospective analysis

    Energy Technology Data Exchange (ETDEWEB)

    Erbay, S.; Han, R.; Baccei, S.; Bhadelia, R.; Polak, J. [Tufts-New England Medical Center, Department of Radiology, Boston, MA (United States); Krakov, W. [Boston University, Department of Radiology, Boston, MA (United States); Zou, K.H. [Brigham and Women' s Hospital, Department of Radiology, Boston, MA (United States)

    2007-01-15

    Our purpose was to study the association between the intracranial arterial calcifications observed on head CT and brain infarcts demonstrated by MRI in patients presenting with acute stroke symptoms. Institutional review board approval was obtained for this retrospective study which included 65 consecutive patients presenting acutely who had both head CT and MRI. Arterial calcifications of the vertebrobasilar system and the intracranial cavernous carotid arteries (intracranial carotid artery calcification, ICAC) were assigned a number (1 to 4) in the bone window images from CT scans. These four groups were then combined into high calcium (grades 3 and 4) and low calcium (grades 1 and 2) subgroups. Brain MRI was independently evaluated to identify acute and chronic large-vessel infarcts (LVI) and small-vessel infarcts (SVI). The relationship between ICAC and infarcts was evaluated before and after adjusting for demographics and cardiovascular risk factors. Statistical analysis could not be performed for the vertebrobasilar system due to an insufficient number of patients in the high calcium group. Of the 65 patients, 46 (71%) had a high ICAC grade on head CT. They were older and had a higher prevalence of cardiovascular risk factors. Acute SVI (P = 0.006), chronic SVI (P = 0.006) and acute LVI (P = 0.04) were associated with a high ICAC grade. After adjustment for age and other risk factors, only acute SVI was associated with a high ICAC grade (P = 0.002). Although age emerged as the most important determinant of ischemic cerebral changes, there were rather complex interactions among multiple risk factors with different infarct types. A high ICAC grade demonstrated a correlation with acute SVI in our patients independent of these risk factors. (orig.)

  8. CT scan suggesting lesions of the both lateral geniculate bodies and the calcarine corteces in a case of traumatic blindness

    Energy Technology Data Exchange (ETDEWEB)

    Mizoi, K.; Nishijima, M. (Tohoku Univ., Sendai (Japan). Shool of Medicine); Onuma, T.

    1981-09-01

    A 29-year-old man fell down the stairs and suffered impact in the left temporo-parietal region. On the following day, although he was stuporous, motor disturbances and anisocoria were not observed, and both pupils normally reacted to light. Carotid angiography showed an avascular area in the left temporal area. Four days after the head injury he showed a generalized tonic-clonic convulsion. He became semicomatose with dilatation of bilateral pupils and decerebrate rigidity of all extremities. An immediate craniotomy was carried out and 100 g. of epidural hematoma was removed. He became fully conscious 6 days after the operation, and he complained of blindness. A CT scan performed 15 days after the operation revealed low density areas occupying the bilateral lateral geniculate bodies and the visual corteces, and these areas were enhanced by contrast medium. These lesions were diagnosed as infarction caused by compression of the posterior cerebral arteries resulting from tentorial herniation. This is the first case reported in the literature.

  9. Survey regarding the clinical practice of cardiac CT in Germany. Indications, scanning technique and reporting

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, Marc H.; Hamm, B.; Dewey, M. [Inst. fuer Radiologie, Charite - Universitaetsmedizin Berlin (Germany)

    2009-12-15

    Purpose: to obtain an overview of the current clinical practice of cardiac computed tomography (CT) in Germany. Materials and methods: a 30-item question-naire was mailed to 149 providers of cardiac CT in Germany. The items asked about indications, scanning technique and reporting, data storage, and cost of the examination. Results: overall 45 questionnaires could be analyzed (30%). The majority of centers (76%, 34 of 45 centers) used CT scanners of the latest generation (at least 64 rows). The most common appropriate indications were exclusion of coronary artery disease (91%, 41/45), coronary anomalies (80%, 36/45), and follow-up after coronary artery bypass grafting (53%, 24/45). Each center examined on average 243 {+-} 310 patients in 2007 and the number of centers performing cardiac CT increased significantly in 2007 (p = 0.035) compared with the preceding year. Most used sublingual nitroglycerin (84%, 38/45; median of 2 sprays = 0.8 mg) and/or a beta blocker (86%, 39/44; median of 5 mg IV, median heart rate threshold: 70 beats/min). Many providers used ECG-triggered tube current modulation (65%, 29/44) and/or adjusted the tube current to the body mass index or body weight (63%, 28/44). A median slice thickness of 0.75 mm with a 0.5 mm increment and a 20 cm field-of-view was most commonly used. Source images in orthogonal planes (96%, 43/45), curved MPRs (93%, 42/45), and thin-slice MIPs (69%, 31/45) were used most frequently for interpretation. Extracardiac structures were also evaluated by 84% of the centers (38/45). The mean examination time was 16.2 min and reporting took an average of 28.8 min. (orig.)

  10. Multiple bony lesions other than femoral heads on {sup 99m}Tc-MDP bone scan in patients with avascular necrosis of the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yun Young; Yang, Seoung Oh; Moon, Dae Hyuk; Ryu, Jin Sook; Weon, Young Cheol; Shin, Myung Jin; Lee, Soo Ho; Lee, Hee Kyung [Asan Medical Center, Ulsan Univ. College of Medicine, Ulsan (Korea, Republic of); Chun, Hae Kyung [St. Francisco Hospital, Seoul (Korea, Republic of)

    1997-03-01

    To evaluate the clinical significance of the multiple increased uptake lesions other than in femoral heads as seen on whole body bone scan in patients with avascular necrosis of femoral heads. One hundred and seventy three patients with clinical diagnosis of avascular necrosis of the emoral head underwent a bone scan using Tc-99m MDP. Increased uptake lesions other than in femoral heads were evaluated, including frequency and common sites of in volvement, and correlated with clinical information and plain radiographic findings. Two hundred patients without AVN, who had undergone a bone scan, were included as a control group. Increased uptake lesions in extrafemoral head locations were found in 36 of 173 patients(20.8%); the location of 79 lesions was other than the femoral head. This result is statistically different from patients without avascular necrosis of femoral head(p<0.0001). The most common site of involvement was the knee joint area(62.5%). Other lesions were located in the mid-shafts of the long bones of the lower extremities, calcaneus, proximal humerus, etc., in order of decreasing frequency. Plain radiographs of 17 lesions were nonspecific, except for three lesions showing definite changes associated with avascular necrosis. The risk factors included alcoholism, the prolonged use of steroids, renal transplantation, herbal medication and working as a working as deep-sea diver. Most patients did not complain of pain, except for two with irreversible osteonecrotic changes as seen on plain radiograph. in patients with avascular necrosis of the femur, increased uptake lesions other than in the femoral head as seen on bone scan, may represent the early stage of osteonecrosis, which shows a characteristic appearance on bone scan. In order to aveid possible misdiagnoses of multiple extrafemoral lesions as bony metastasis or traumatic lesions, in patients with avascular necrosis of the femur these should be carefully evaluated.

  11. [Exposure to CT scans in childhood and long-term cancer risk: A review of epidemiological studies].

    Science.gov (United States)

    Baysson, Hélène; Journy, Neige; Roué, Tristan; Ducou-Lepointe, Hubert; Etard, Cécile; Bernier, Marie-Odile

    2016-02-01

    Amongst medical exams requiring ionizing radiation, computed tomography (CT) scans are used more frequently, including in children. These CT examinations are associated with absorbed doses that are much higher than those associated with conventional radiology. In comparison to adults, children have a greater sensitivity to radiation and a longer life span with more years at cancer risks. Five epidemiological studies on cancer risks after CT scan exposure during childhood were published between 2012 and 2015. The results of these studies are consistent and show an increase of cancer risks in children who have been exposed to several CT scans. However, methodological limits due to indication bias, retrospective assessment of radiation exposure from CT scans and lack of statistical power are to be taken into consideration. International projects such as EPI-CT (Epidemiological study to quantify risks for pediatric computerized tomography and to optimize dose), with a focus on dosimetric reconstruction and minimization of bias will provide more precise results. In the meantime, available results reinforce the necessity of justification and optimization of doses.

  12. Digital forensic osteology: morphological sexing of skeletal remains using volume-rendered cranial CT scans.

    Science.gov (United States)

    Ramsthaler, Frank; Kettner, Mattias; Gehl, Axel; Verhoff, M A

    2010-02-25

    Because of the increasing lack of recent bone collections, ethical issues concerning maceration procedures, and progress in radiological imaging techniques, computed tomography (CT) scans offer an alternative to traditional anthropological bone collection. The present study examined volume-rendered cranial CT (CCT) scans from 50 crania to morphologically evaluate sex characteristics. CCT scans were performed and scored by two teams (Teams A and B) of two examiners each (2x50=100 examinations) to evaluate the occurrence and/or absence of morphological traits. Altogether, 60 of 100 crania (31 Team A+29 Team B) crania were determined to be male, and 40 (19 Team A+21 Team B) were determined to be female when using the scoring system adapted from Knussmann. These results imply a sex determination accuracy rate of 96%. Only in one case was recalculation of weighting factors necessary to determine one additional correct classification. As a single parameter, arcus superciliaris evaluation permitted the most accurate sex determination (female, 84.2%; male, 85.5%). No significant difference in accuracy rates was observed between the two sexes (p<0.65, chi(2)=0.39, Fisher's exact test). Interobserver bias rates for both teams were very low (kappa=0.83). The present study shows that volume-rendered CCT images are suitable for the collection of data concerning morphologic sex determination of skulls. Thus, this method may be helpful in both actual forensic casework and the systematic reevaluation and improvement of classical anthropological methods and their adaptation to changing populations.

  13. Multiphase CT scanning and different intravenous contrast media concentrations in combined F-18-FDG PET/CT: Effect on quantitative and clinical assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rebiere, Marilou, E-mail: Marilou.Rebiere@rwth-aachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Verburg, Frederik A., E-mail: fverburg@ukaachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Department of Nuclear Medicine, Maastricht University Medical Center, P. Debeylaan 25, 6202 AZ Maastricht (Netherlands); Palmowski, Moritz, E-mail: mpalmowski@ukaachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Department of Radiology, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Department of Experimental Molecular Imaging, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Krohn, Thomas, E-mail: tkrohn@ukaachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Pietsch, Hubertus, E-mail: hubertus.pietsch@bayer.com [Contrast Media Research, Bayer Pharma AG, Muellerstr. 178, 13353 Berlin (Germany); Kuhl, Christiane K., E-mail: ckuhl@ukaachen.de [Department of Radiology, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Mottaghy, Felix M., E-mail: fmottaghy@ukaachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Department of Nuclear Medicine, Maastricht University Medical Center, P. Debeylaan 25, 6202 AZ Maastricht (Netherlands); Behrendt, Florian F., E-mail: fbehrendt@ukaachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany)

    2012-08-15

    Purpose: To evaluate the influence of multiphase CT scanning and different intravenous contrast media on contrast enhancement, attenuation correction and image quality in combined PET/CT. Material and methods: 140 patients were prospectively enrolled for F-18-FDG-PET/CT including a low-dose unenhanced, arterial and venous contrast enhanced CT. The first (second) 70 patients, received contrast medium with 370 (300) mg iodine/ml. The iodine delivery rate (1.3 mg/s) and total iodine load (44.4 g) were identical for both groups. Contrast enhancement and maximum and mean standardized FDG uptake values (SUVmax and SUVmean) were determined for the un-enhanced, arterial and venous PET/CT at multiple anatomic sites and PET reconstructions were visually evaluated. Results: Arterial contrast enhancement was significantly higher for the 300 mg/ml contrast medium compared to 370 mg I/ml at all anatomic sites. Venous enhancement was not different between the two contrast media. SUVmean and SUVmax were significantly higher for the contrast enhanced compared to the non-enhanced PET/CT at all anatomic sites (all P < 0.001). Tracer uptake was significantly higher in the arterial than in the venous PET/CT in the arteries using both contrast media (all P < 0.001). No differences in tracer uptake were found between the contrast media (all P > 0.05). Visual assessment revealed no relevant differences between the different PET reconstructions. Conclusions: There is no relevant qualitative influence on the PET scan from the use of different intravenous contrast media in its various phases in combined multiphase PET/CT. For quantitative analysis of tracer uptake it is required to use an identical PET/CT protocol.

  14. Verification of CTDI and Dlp values for a head tomography reported by the manufacturers of the CT scanners, using a CT dose profiler probe, a head phantom and a piranha electrometer

    Energy Technology Data Exchange (ETDEWEB)

    Castillo C, E.; Garcia F, I. B.; Garcia H, J.; Roman L, S. [Servicios de Salud de Michoacan, Centro Estatal de Atencion Oncologica, Gertrudis Bocanegra No. 300, Col. Cuauhtemoc, 58020 Morelia, Michoacan (Mexico); Salmeron C, O., E-mail: edithcastillocorona@gmail.com [Servicios de Salud de Michoacan, Hospital General Dr. Miguel Silva, Isidro Huarte s/n, Centro Historico, 58000 Morelia, Michoacan (Mexico)

    2015-10-15

    The extensive use of Computed Tomography (CT) and the associated increase in patient dose calls for an accurate dose evaluation technique. The CT contributes up to 70% of the total dose given to patients during X-ray examinations. The rapid advancements in CT technology are placing new demands on the methods and equipment that are used for quality assurance. The wide beam widths found in CT scanners with multiple beam apertures make it impossible to use existing CT ionization chambers to measure the total dose given to the patient. Using a standard 10 cm CT ionization chamber may result in inaccurate measurements due to underestimation of the dose profile for wide beams. The use a CT dose profiler based on solid-state technology and the Piranha electrometer from RTI electronics provides a potential solution to the arising concerns over patient dose. This study intend to evaluate the feasibility and accuracy of CT Dose Index (CTDI) and Dose Length Product (Dlp) values for a head tomography reported by the manufacturers of the CT scanners at each study. (Author)

  15. Moving metal artifact reduction in cone-beam CT scans with implanted cylindrical gold markers

    Energy Technology Data Exchange (ETDEWEB)

    Toftegaard, Jakob, E-mail: jaktofte@rm.dk; Fledelius, Walther; Worm, Esben S.; Poulsen, Per R. [Department of Oncolog