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Sample records for dcta

  1. Three dimensional CT angiography (3D-CTA) in ruptured aneurysm surgery on acute stage

    International Nuclear Information System (INIS)

    Matsumoto, Masato; Endo, Yuji; Nakano, Masayuki

    1998-01-01

    We evaluated three-dimensional CT angiography (3D-CTA) for the treatment of acutely ruptured cerebral aneurysms. Sixty patients with subarachnoid hemorrhage from cerebral aneurysms were investigated both by 3D-CTA and conventional angiography and 26 patients were studied using 3D-CTA without conventional angiography. In the 60 cases, both 3D-CTA and the conventional angiography revealed 100% accuracy in diagnosing ruptured aneurysms, and 3D-CTA and the conventional angiography showed 96% and 92% accuracy for unruptured aneurysms respectively. 3D-CTA was equal or superior to the conventional angiography. Based on these data, since December, 1996, we have operated on 26 consecutive patients with ruptured aneurysms located in the anterior circulation of the circle of Willis, using 3D-CTA without conventional angiography. Thirty-one aneurysms, including 5 associated unruptured aneurysms, were visualized by 3D-CTA and verified at surgery. All aneurysms were clipped successfully. We think that it will be possible to operate on most ruptured aneurysms using only 3D-CTA without the conventional angiography except for the cases of the following situations: if a cerebral infarction is present, conventional angiography is required to evaluate for a stenotic or occlusive lesion of the intracranial arteries, cervical carotid, or vertebral arteries; in cases of giant or large aneurysms, the dynamic information provided by the conventional angiography is needed in case bypass surgery is necessary; and for aneurysms close to bony structures, such as an internal carotid-ophthalmic artery aneurysm, conventional angiography is necessary. (author)

  2. The use of 4D-CTA in the diagnostic work-up of brain arteriovenous malformations

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    Willems, Peter W.A. [Toronto Western Hospital, UHN, Division of Neuroradiology, Department of Medical Imaging, Toronto, Ontario (Canada); Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Taeshineetanakul, Patamintita; Terbrugge, Karel G.; Krings, Timo [Toronto Western Hospital, UHN, Division of Neuroradiology, Department of Medical Imaging, Toronto, Ontario (Canada); Schenk, Barry; Brouwer, Patrick A. [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands)

    2012-02-15

    We aimed to evaluate the use of time-resolved whole-head CT angiography (4D-CTA) in patients with an untreated arteriovenous malformation of the brain (bAVM), as demonstrated by catheter angiography (DSA). Seventeen patients with a DSA-proven bAVM were enrolled. These were subjected to 4D-CTA imaging using a 320 detector row CT scanner. Using a standardized scoring sheet, all studies were analyzed by a panel of three readers. This panel was blind to the DSA results at the time of reading the 4D-CTA. 4D-CTA detected all bAVMs. With regard to the Spetzler-Martin grade, 4D-CTA disagreed with DSA in only one case, where deep venous drainage was missed. Further discrepancies between 4D-CTA and DSA analyses included underestimation of the nidus size in small lesions (four cases), misinterpretation of a feeding vessel (one case), misinterpretation of indirect feeding through pial collaterals (three cases) and oversight of mild arterial enlargement (two cases). 4D-CTA correctly distinguished low-flow from high-flow lesions and detected dural/transosseous feeding (one case), venous narrowing (one case) and venous pouches (nine cases). In this series, 4D-CTA was able to detect all bAVMs. Although some angioarchitectural details were missed or misinterpreted when compared to DSA, 4D-CTA evaluation was sufficiently accurate to diagnose the shunt and classify it. Moreover, 4D-CTA adds cross-sectional imaging and perfusion maps, helpful in treatment planning. 4D-CTA appears to be a valuable new adjunct in the non-invasive diagnostic work-up of bAVMs and their follow-up when managed conservatively. (orig.)

  3. The use of 4D-CTA in the diagnostic work-up of brain arteriovenous malformations

    International Nuclear Information System (INIS)

    Willems, Peter W.A.; Taeshineetanakul, Patamintita; Terbrugge, Karel G.; Krings, Timo; Schenk, Barry; Brouwer, Patrick A.

    2012-01-01

    We aimed to evaluate the use of time-resolved whole-head CT angiography (4D-CTA) in patients with an untreated arteriovenous malformation of the brain (bAVM), as demonstrated by catheter angiography (DSA). Seventeen patients with a DSA-proven bAVM were enrolled. These were subjected to 4D-CTA imaging using a 320 detector row CT scanner. Using a standardized scoring sheet, all studies were analyzed by a panel of three readers. This panel was blind to the DSA results at the time of reading the 4D-CTA. 4D-CTA detected all bAVMs. With regard to the Spetzler-Martin grade, 4D-CTA disagreed with DSA in only one case, where deep venous drainage was missed. Further discrepancies between 4D-CTA and DSA analyses included underestimation of the nidus size in small lesions (four cases), misinterpretation of a feeding vessel (one case), misinterpretation of indirect feeding through pial collaterals (three cases) and oversight of mild arterial enlargement (two cases). 4D-CTA correctly distinguished low-flow from high-flow lesions and detected dural/transosseous feeding (one case), venous narrowing (one case) and venous pouches (nine cases). In this series, 4D-CTA was able to detect all bAVMs. Although some angioarchitectural details were missed or misinterpreted when compared to DSA, 4D-CTA evaluation was sufficiently accurate to diagnose the shunt and classify it. Moreover, 4D-CTA adds cross-sectional imaging and perfusion maps, helpful in treatment planning. 4D-CTA appears to be a valuable new adjunct in the non-invasive diagnostic work-up of bAVMs and their follow-up when managed conservatively. (orig.)

  4. Minimally invasive vascular imaging using 3D-CTA and 3D-MRA. Update

    International Nuclear Information System (INIS)

    Hayashi, Hiromitsu; Kawamata, Hiroshi; Takagi, Ryo; Amano, Yasuo; Wakabayashi, Hiroyuki; Ichikawa, Kazuo; Kumazaki, Tatsuo

    1998-01-01

    Conventional angiography is considered the standard of reference for diagnostic imaging of vascular diseases with respect to its temporal and spatial resolution. This procedure, however is invasive and repeated studies are difficult, and arterial complications are occasionally associated in catheter-based conventional angiography. Recent advances in diagnostic imaging have facilitated three-dimensional CT angiography (3D-CTA) using the volumetric acquisition capabilities inherent in spiral CT and three-dimensional MR angiography (3D-MRA) using the 3D gradient-echo sequence with a bolus injection of Gd-DTPA. These techniques can provide vascular images exceedingly similar to conventional angiograms within a short acquisition time. 3D-CTA and 3D-MRA are considered to be promising, minimally invasive methods for obtaining images of the vasculature, and alternatives to catheter angiography. This study reviews the current status of 3D-CTA and 3D-MRA, with emphasis on the clinical usefulness of three-dimensional diagnostic imaging for the evaluation of diverse vascular pathologies. (author)

  5. Differentiation of DctA and DcuS function in the DctA/DcuS sensor complex of Escherichia coli: function of DctA as an activity switch and of DcuS as the C4-dicarboxylate sensor.

    Science.gov (United States)

    Steinmetz, Philipp Aloysius; Wörner, Sebastian; Unden, Gottfried

    2014-10-01

    The C4-dicarboxylate responsiveness of the sensor kinase DcuS is only provided in concert with C4-dicarboxylate transporters DctA or DcuB. The individual roles of DctA and DcuS for the function of the DctA/DcuS sensor complex were analysed. (i) Variant DctA(S380D) in the C4-dicarboxylate site of DctA conferred C4-dicarboxylate sensitivity to DcuS in the DctA/DcuS complex, but was deficient for transport and for growth on C4-dicarboxylates. Consequently transport activity of DctA is not required for its function in the sensor complex. (ii) Effectors like fumarate induced expression of DctA/DcuS-dependent reporter genes (dcuB-lacZ) and served as substrates of DctA, whereas citrate served only as an inducer of dcuB-lacZ without affecting DctA function. (iii) Induction of dcuB-lacZ by fumarate required 33-fold higher concentrations than for transport by DctA (Km  = 30 μM), demonstrating the existence of different fumarate sites for both processes. (iv) In titration experiments with increasing dctA expression levels, the effect of DctA on the C4-dicarboxylate sensitivity of DcuS was concentration dependent. The data uniformly show that C4-dicarboxylate sensing by DctA/DcuS resides in DcuS, and that DctA serves as an activity switch. Shifting of DcuS from the constitutive ON to the C4-dicarboxylate responsive state, required presence of DctA but not transport by DctA. © 2014 John Wiley & Sons Ltd.

  6. Optimization of the Reconstruction Interval in Neurovascular 4D-CTA Imaging

    Science.gov (United States)

    Hoogenboom, T.C.H.; van Beurden, R.M.J.; van Teylingen, B.; Schenk, B.; Willems, P.W.A.

    2012-01-01

    Summary Time resolved whole brain CT angiography (4D-CTA) is a novel imaging technology providing information regarding blood flow. One of the factors that influence the diagnostic value of this examination is the temporal resolution, which is affected by the gantry rotation speed during acquisition and the reconstruction interval during post-processing. Post-processing determines the time spacing between two reconstructed volumes and, unlike rotation speed, does not affect radiation burden. The data sets of six patients who underwent a cranial 4D-CTA were used for this study. Raw data was acquired using a 320-slice scanner with a rotation speed of 2 Hz. The arterial to venous passage of an intravenous contrast bolus was captured during a 15 s continuous scan. The raw data was reconstructed using four different reconstruction-intervals: 0.2, 0.3, 0.5 and 1.0 s. The results were rated by two observers using a standardized score sheet. The appearance of each lesion was rated correctly in all readings. Scoring for quality of temporal resolution revealed a stepwise improvement from the 1.0 s interval to the 0.3 s interval, while no discernable improvement was noted between the 0.3 s and 0.2 s interval. An increase in temporal resolution may improve the diagnostic quality of cranial 4D-CTA. Using a rotation speed of 0.5 s, the optimal reconstruction interval appears to be 0.3 s, beyond which, changes can no longer be discerned. PMID:23217631

  7. Four-dimensional CT angiography (4D-CTA) in the evaluation of juvenile nasopharyngeal angiofibromas: comparison with digital subtraction angiography (DSA) and surgical findings.

    Science.gov (United States)

    Xiao, Zebin; Zheng, Yingyan; Li, Jian; Chen, Dehua; Liu, Fang; Cao, Dairong

    2017-12-01

    To explore the value of four-dimensional CT angiography (4D-CTA) in the preoperative evaluation of juvenile nasopharyngeal angiofibromas (JNAs) using 320-row volume CT. 4D-CTA and DSA data of 18 patients with histopathologically proven JNAs were retrospectively reviewed. The location, extent, feeding vessels and stage of JNAs were assessed by two radiologists independently and blindly. The agreements between both reviewers and between 4D-CTA and surgical findings for assessing the above indicators were analysed, respectively. The radiation dose and the number of feeding arteries between 4D-CTA and digital subtraction angiography (DSA) were also compared. 4D-CTA showed high diagnostic consistency with surgical pathology for JNAs with consistent rates of 96.2 and 100% in both reviewers, respectively. The effective dose of 4D-CTA was significantly less than that of DSA (p 0.05). 4D-CTA can provide a reliable preoperative diagnosis and assessment of JNAs, which is useful for determining the surgical strategy and management of this condition.

  8. Helical CT for emergency patients with cerebrovascular diseases. Diagnosis of cerebral aneurysms with subarachnoid hemorrhage (SAH) by three-dimensional CT angiography (3D-CTA)

    International Nuclear Information System (INIS)

    Matsumoto, Masato; Satoh, Naoki; Kobayashi, Touru; Kodama, Namio; Nakano, Masayuki; Watanabe, Youichi; Fujii, Masayuki

    1996-01-01

    Recently, the usefulness of three-dimensional CT angiography (3D-CTA) using helical CT has been reported. Although 3D-CTA has been applied for neurosurgical diseases, especially for surgical planning, it has not done for emergency patients because of the long time required for image reconstruction and location of a helical CT scanner. We studied emergency patients with SAH, and compared the 3D-CTA with angiography and surgical findings, using TOSHIBA X vigor. Twenty-two patients with SAH were evaluated. The helical CT was performed for 55 seconds with a bolus injection of 90 ml non-ionic, iodinated contrast medium at a rate of 3 ml/sec with a delay of 20 sec. Angiography was carried out immediately after the helical CT. Eighteen of 22 cases were operated on urgently. We were able to create the 3D-CTA in about 7 minutes, and diagnose aneurysms by the 3D-CTA before angiography. The 3D-CTA was able to demonstrate 30 of 31 aneurysms including 9 unruptured aneurysms. An unruptured internal carotid-posterior communicating artery aneurysm 1.3 mm in diameter and associated with a ruptured aneurysm was not detected by either the 3D-CTA or angiography. On the other hand, an unruptured Acom aneurysm 0.8 mm in diameter and associated with a ruptured aneurysm could be detected by the: 3D-CTA, but not by angiography. The 3D-CTA gave us useful information concerning the anatomical relationship of the aneurysm, its neck and parent artery, and the surrounding branches. There were no complications or side effects associated with the helical CT scan. Although the 3D-CTA requires further development of visualization of small arteries less than 1 mm in diameter, such as perforating arteries, subtraction technique of bony structure, and a method for checking cervical arteries, it is useful for diagnosis of emergency patients with SAH and urgent operations. We believe that an operation might be performed by only the 3D-CTA without the angiography in the near future. (author)

  9. Helical CT for emergency patients with cerebrovascular diseases. Diagnosis of cerebral aneurysms with subarachnoid hemorrhage (SAH) by three-dimensional CT angiography (3D-CTA)

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    Matsumoto, Masato; Satoh, Naoki; Kobayashi, Touru; Kodama, Namio; Nakano, Masayuki; Watanabe, Youichi; Fujii, Masayuki [Fukushima Medical School (Japan)

    1996-05-01

    Recently, the usefulness of three-dimensional CT angiography (3D-CTA) using helical CT has been reported. Although 3D-CTA has been applied for neurosurgical diseases, especially for surgical planning, it has not done for emergency patients because of the long time required for image reconstruction and location of a helical CT scanner. We studied emergency patients with SAH, and compared the 3D-CTA with angiography and surgical findings, using TOSHIBA X vigor. Twenty-two patients with SAH were evaluated. The helical CT was performed for 55 seconds with a bolus injection of 90 ml non-ionic, iodinated contrast medium at a rate of 3 ml/sec with a delay of 20 sec. Angiography was carried out immediately after the helical CT. Eighteen of 22 cases were operated on urgently. We were able to create the 3D-CTA in about 7 minutes, and diagnose aneurysms by the 3D-CTA before angiography. The 3D-CTA was able to demonstrate 30 of 31 aneurysms including 9 unruptured aneurysms. An unruptured internal carotid-posterior communicating artery aneurysm 1.3 mm in diameter and associated with a ruptured aneurysm was not detected by either the 3D-CTA or angiography. On the other hand, an unruptured Acom aneurysm 0.8 mm in diameter and associated with a ruptured aneurysm could be detected by the: 3D-CTA, but not by angiography. The 3D-CTA gave us useful information concerning the anatomical relationship of the aneurysm, its neck and parent artery, and the surrounding branches. There were no complications or side effects associated with the helical CT scan. Although the 3D-CTA requires further development of visualization of small arteries less than 1 mm in diameter, such as perforating arteries, subtraction technique of bony structure, and a method for checking cervical arteries, it is useful for diagnosis of emergency patients with SAH and urgent operations. We believe that an operation might be performed by only the 3D-CTA without the angiography in the near future. (author)

  10. Microsurgical management of cerebral aneurysms based in CT angiography with three-dimensional reconstruction (3D-CTA) and without preoperative cerebral angiography

    International Nuclear Information System (INIS)

    Gonzalez-Darder, J.M.; Pesudo-Martinez, J.V.; Feliu-Tatay, R.A.

    2001-01-01

    Objective. To study the possibilities of the microsurgical management of ruptured intracranial aneurysms with the sole preoperative information provided by computed tomography angiography with three-dimensional reconstruction (3D-CTA). Methods. Patients were studied with 3D-CTA after diagnosis of subarachnoid hemorrhage. If the study had an adequate quality and revealed an aneurysm congruent with the clinical findings or neurological examination and/or with the location of the bleeding on computed tomography (CT) scan an early microsurgical clipping of the lesion was done. When the quality of the 3D-CTA study was not adequate or the quality being adequate displayed no lesions or the findings were not accurate enough to warrant direct microsurgical treatment, the patient was studied with cerebral digital substraction (DS) angiography. A total of 44 consecutive patients harboring a total of 47 intracranial aneurysms diagnosed by 3D-CTA and without preoperative DS angiography were submitted to microsurgical clipping and included in the study. Results. The overall mortality was 15.9 % and the favorable results evaluated 6 months after discharge by means of the Glasgow outcome scale reached 70.4 %. All lesions were successfully clipped. Surgery was done a mean of 4.1 days after the admission bleeding. A total of four microlesions undiagnosed by 3D-CTA were found at surgery and clipped. Postoperative DS angiography and necropsy findings were also used as control of the 3D-CTA findings but no additional information was provided excepting the finding in DS angiography of an asymptomatic intracavemous aneurysm. Therefore the sensitivity of the 3D-CTA for diagnosis of symtomatic aneurysms was 100 % and the overall sensitivity 90.4 %. Conclusions. We have reached similar results in patients operated on with or without preoperative angiography. 3D-CTA provides very valuable anatomical information, which has an additional value in the microsurgical treatment of aneurysms of the

  11. Differential diagnosis between aneurysm and infundibular dilatation in the IC-PC region with 3D-CTA

    International Nuclear Information System (INIS)

    Kubota, Tsukasa; Niwa, Jun; Tanigawara, Tetsuya; Chiba, Masahiko; Akiyama, Yukinori; Inamura Shigeru

    2000-01-01

    In cases of asymptomatic internal carotid-posterior communicating artery (IC-PC) protrusions, it is sometimes difficult to differentiate infundibular dilatation (ID) from aneurysm by digital subtraction angiography. We applied three-dimensional CT angiography (3D-CTA) in 32 cases of these IC-PC protrusions. SOMATOM PLUS 4 was used under such conditions as to provide images with high spatial resolution. The shaded surface display (SSD) method was adopted to reconstruct the 3D images because of its advantage in separating overlapped vasculature. We also made reference to source images and maximum intensity projection (MIP) to make sure of our diagnoses. In all cases including 4 aneurysms and 28 IDs, we were able to distinguish between ID and aneurysm. The accuracy of 3D-CTA was confirmed by 9 surgical cases. Our technique was as follows: To inject a high dose of diluted contrast medium rapidly to smaller arteries for opacification of contrast medium. To exclude neighboring useless structures except for the very close structures such as posterior clinoid process from the target image focusing on the IC-PC region. To observe the reconstructed image of MIP and SSD from various angles. The contralateral and craniocaudal view were valuable. To change the threshold level gradually and observe the configurational changes of the apex of protrusion. Poorly developed PcomA was mostly delineated at the optimum threshold level. Otherwise, the apex of protrusion remained spherical in an aneurysm and became pyramidal in shape in an ID when the threshold level was gradually decreased. In conclusion, 3D-CTA was a useful modality for IC-PC protrusions to distinguish between ID and aneurysm. (author)

  12. Involvement of the Acr3 and DctA anti-porters in arsenite oxidation in Agrobacterium tumefaciens 5A.

    Science.gov (United States)

    Kang, Yoon-Suk; Shi, Zunji; Bothner, Brian; Wang, Gejiao; McDermott, Timothy R

    2015-06-01

    Microbial arsenite (AsIII) oxidation forms a critical piece of the arsenic cycle in nature, though our understanding of how and why microorganisms oxidize AsIII remains rudimentary. Our model organism Agrobacterium tumefaciens 5A contains two distinct ars operons (ars1 and ars2) that are similar in their coding region content. The ars1 operon is located nearby the aio operon that is essential for AsIII oxidation. The AsIII/H(+) anti-porters encoded by acr3-1 and acr3-2 are required for maximal AsIII and antimonite (SbIII) resistance, but acr3-1 (negatively regulated by ArsR-1) appears more active in this regard and also required for AsIII oxidation and expression of aioBA. A malate-phosphate anti-porter DctA is regulated by RpoN and AsIII, and is required for normal growth with malate as a sole carbon source. Qualitatively, a ΔdctA mutant was normal for AsIII oxidation and AsIII/SbIII resistance at metalloid concentrations inhibitory to the Δacr3-1 mutant; however, aioBA induction kinetics was significantly phase-shift delayed. Acr3 involvement in AsIII/SbIII resistance is reasonably well understood, but the role of Acr3 and DctA anti-porters in AsIII oxidation and its regulation is unexpected, and suggests that controlled AsIII trafficking across the cytoplasmic membrane is important to a process understood to occur in the periplasm. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  13. Polar localization of a tripartite complex of the two-component system DcuS/DcuR and the transporter DctA in Escherichia coli depends on the sensor kinase DcuS.

    Directory of Open Access Journals (Sweden)

    Patrick D Scheu

    Full Text Available The C4-dicarboxylate responsive sensor kinase DcuS of the DcuS/DcuR two-component system of E. coli is membrane-bound and reveals a polar localization. DcuS uses the C4-dicarboxylate transporter DctA as a co-regulator forming DctA/DcuS sensor units. Here it is shown by fluorescence microscopy with fusion proteins that DcuS has a dynamic and preferential polar localization, even at very low expression levels. Single assemblies of DcuS had high mobility in fast time lapse acquisitions, and fast recovery in FRAP experiments, excluding polar accumulation due to aggregation. DctA and DcuR fused to derivatives of the YFP protein are dispersed in the membrane or in the cytosol, respectively, when expressed without DcuS, but co-localize with DcuS when co-expressed at appropriate levels. Thus, DcuS is required for location of DctA and DcuR at the poles and formation of tripartite DctA/DcuS/DcuR sensor/regulator complexes. Vice versa, DctA, DcuR and the alternative succinate transporter DauA were not essential for polar localization of DcuS, suggesting that the polar trapping occurs by DcuS. Cardiolipin, the high curvature at the cell poles, and the cytoskeletal protein MreB were not required for polar localization. In contrast, polar localization of DcuS required the presence of the cytoplasmic PAS(C and the kinase domains of DcuS.

  14. Contrast enhancement technique in brain 3D-CTA studies. Optimizing the amount of contrast medium according to scan time based on TDC

    International Nuclear Information System (INIS)

    Terasawa, Kazuaki; Hatcho, Atsushi

    2008-01-01

    In three-dimensional CT angiography (3D-CTA), good reproducibility can be obtained by maintaining the maximum CT numbers (HU) at a specified level. However, the correlation between the scan time and the injection time showed that the maximum CT numbers increased and varied due to the additional contrast enhancement effect from recirculation of the injected contrast medium for longer injection times when the dose of iodinated contrast medium per unit time (mgI/s) was maintained at a specified level based on the time-density curve (TDC) of the phantom. The amount of contrast medium employed at our hospital has been optimized based on an iodinated contrast medium dose per unit time providing a contrast enhancement effect of 300 HU in the middle cerebral artery. Using this standard, a TDC phantom was employed to obtain an iodinated contrast medium dose per unit time, permitting equivalent maximum CT values (used as standard values) to be obtained by changing the injection time. A contrast-enhancement technique that accounts for the variation in the scan time was evaluated. Strong correlations were observed between the scan time and the injection time (R 2 =0.969) and between the injection time and the dose of iodinated contrast medium per unit body weight (R 2 =0.994). We conclude that adjusting the dose of iodinated contrast medium per unit body weight per unit time according to the scan time permits optimization of the contrast-enhancement technique. (author)

  15. Detection of thin wall regions of unruptured cerebral aneurysms by ECG synchronous reconstruction 3D-CT angiography (4D-CTA) using 16 slices per rotation CT

    International Nuclear Information System (INIS)

    Fujita, Shigekiyo

    2004-01-01

    The objective of this study was to evaluate the capability of electrocardiogram (ECG) synchronous reconstruction 3D-CT angiography (4D-CTA) using 16 sequence MD-CT to detect weak portions of unruptured cerebral aneurysm. 4D-CT angiography of unruptured cerebral aneurysms was performed on 26 patients, 28 cerebral aneurysms, using 16 sequence MD-CT (GE, HiLight Matrix II). Contrast material of iodine (300 mg/ml) was injected over 30 sec period into the ante-cubital vein with a rate of 0.06 ml/Kg/sec. ECG synchronous reconstruction images (10 images at intervals of 10% between R-R of ECG) were generated (GE, Workstation Advantage 4.1). After careful inspection of the wall motion of an aneurysm from many aspects, cine images were made from several directions. Acquisition of data required 9 seconds, total volume data were generated within 15 minutes, and ECG synchronous reconstruction image processing was performed in about 5 minutes. Animation creation for one direction was completed within one minute. Even in 3-mm aneurysms, changes of its form and size within a heartbeat were fully observed. Timing of maximum and minimum sizes were also recognized. The pulsatile changes and nipple extent, bleb, daughter, and dome of aneurysms were well visualized. The projecting motion of the pulsatory enlargement of nipple was detected in nine cases, and definite increases in bleb sizes were detected in five cases. Since the easily reptured thin walled portion of a cerebral aneurysm can be recognized by this method, 4D-CT angiography is likely to become indispensable in judging how to cope with unruptured cerebral aneurysms, in deciding whether to operate or observe. (author)

  16. Real-time respiration monitoring using the radiotherapy treatment beam and four-dimensional computed tomography (4DCT)-a conceptual study

    International Nuclear Information System (INIS)

    Lu Weiguo; Ruchala, Kenneth J; Chen, Ming-Li; Chen, Quan; Olivera, Gustavo H

    2006-01-01

    Real-time knowledge of intra-fraction motion, such as respiration, is essential for four-dimensional (4D) radiotherapy. Surrogate-based and internal-fiducial-based methods may suffer from one or many drawbacks such as false correlation, being invasive, delivering extra patient radiation, and requiring complicated hardware and software development and implementation. In this paper we develop a simple non-surrogate, non-invasive method to monitor respiratory motion during radiotherapy treatments in real time. This method directly utilizes the treatment beam and thus imposes no additional radiation to the patient. The method requires a pre-treatment 4DCT and a real-time detector system. The method combines off-line processes with on-line processes. The off-line processes include 4DCT imaging and pre-calculating detector signals at each phase of the 4DCT based on the planned fluence map and the detector response function. The on-line processes include measuring detector signal from the treatment beam, and correlating the measured detector signal with the pre-calculated signals. The respiration phase is determined as the position of peak correlation. We tested our method with extensive simulations based on a TomoTherapy machine and a 4DCT of a lung cancer patient. Three types of simulations were implemented to mimic the clinical situations. Each type of simulation used three different TomoTherapy delivery sinograms, each with 800 to 1000 projections, as input fluences. Three arbitrary breathing patterns were simulated and two dose levels, 2 Gy/fraction and 2 cGy/fraction, were used for simulations to study the robustness of this method against detector quantum noise. The algorithm was used to determine the breathing phases and this result was compared with the simulated breathing patterns. For the 2 Gy/fraction simulations, the respiration phases were accurately determined within one phase error in real time for most projections of the treatment, except for a few projections at the start and end of the treatment in which beam intensities were extremely low. At 2 cGy/fraction dose level, the method can still determine the respiration phase very well with less than 10% of projections having more than two phases (∼1 s) error. This technique can also be applied in other delivery systems such as orthogonal x-ray systems, although in those cases it would entail the delivery of additional non-treatment radiation

  17. Three-dimensional CT angiography in the diagnosis of cerebrovascular disease

    International Nuclear Information System (INIS)

    Eguchi, Takahiko; Nikaido, Yuji; Nakamura, Takeshi; Yoneda, Shigeru

    1995-01-01

    We reported the usefulness of three dimensional CT angiography (3 DCTA) in cerebrovascular disease. Twenty two of twenty three intracerebral aneurysms were visualized in 3 DCTA. 3 DTPA was especially useful for the evaluation of posterior-projection anterior communicating arteries and the distinction between a carotid-posterior communicating aneurysm and an infundibular dilatation. An anterior-projection carotid bifurcation aneurysm, which we missed in DSA, was visualized clearly in 3 DCTA. Stenotic cervical carotid artery lesions were well evaluated in 3 DCTA, including ulceration. 3 DCTA was not so useful for evaluation of intracranial artery stenosis. 3 DCTA was useful as a non-invasive method to evaluate cerebrovascular diseases. (author)

  18. 3D-CT angiography. Intracranial arterial lesions

    Energy Technology Data Exchange (ETDEWEB)

    Asato, Mikio; Tong, X.Q.; Tamura, Shozo [Miyazaki Medical Coll., Kiyotake (Japan)] [and others

    1997-06-01

    Since its introduction, three dimensional CT angiography (3D-CTA) on spiral (helical) CT has played an important role in clinical imaging. Initially it was reported to be useful in depicting aortic abnormalities, afterwards the merit in detecting intracranial aneurysm by 3D-CTA was also described. We have investigated the usefullness of 3D-CTA in detecting patients of intracranial aneurysm as well as arterio-venous malformation (AVM), Moyamoya disease and stenosis of middle cerebral artery, meanwhile the MR angiography (MRA) and digital subtraction angiography (DSA) examination of these patients were also studied as comparison to the 3D-CTA results. The sensitivity and specificity on investigating intracranial aneurysm were similar with other reports so far. 3D-CTA was possible to identify the feeding artery, nidus and draining vein of AVM, although DSA showed higher detectability. Occlusion of internal carotid artery and post-operative anastomosis in Moyamoya disease were all demonstrated by 3D-CTA, however the Moyamoya collaterals were shown better on MRA. 3D-CTA revealed the site of stenosis of middle cerebral artery in all of our cases, but in general maximum intensity projection (MIP) images can provide more exact information about the degree of stenosis. Five years has passed since the emergence of spiral CT and utilizing of 3D-CTA in clinical applications. With the development of hard and soft ware in the near future, it is possible to delineate more small vessels by 3D-CTA. We predict that 3D-CTA would be widely used for detecting vasculature of the whole body, and may take the place of conventional angiography in many cases. (author)

  19. Added value of delayed computed tomography angiography in primary intracranial hemorrhage and hematoma size for predicting spot sign.

    Science.gov (United States)

    Wu, Te Chang; Chen, Tai Yuan; Shiue, Yow Ling; Chen, Jeon Hor; Hsieh, Tsyh-Jyi; Ko, Ching Chung; Lin, Ching Po

    2018-04-01

    Background The computed tomography angiography (CTA) spot sign represents active contrast extravasation within acute primary intracerebral hemorrhage (ICH) and is an independent predictor of hematoma expansion (HE) and poor clinical outcomes. The spot sign could be detected on first-pass CTA (fpCTA) or delayed CTA (dCTA). Purpose To investigate the additional benefits of dCTA spot sign in primary ICH and hematoma size for predicting spot sign. Material and Methods This is a retrospective study of 100 patients who underwent non-contrast CT (NCCT) and CTA within 24 h of onset of primary ICH. The presence of spot sign on fpCTA or dCTA, and hematoma size on NCCT were recorded. The spot sign on fpCTA or dCTA for predicting significant HE, in-hospital mortality, and poor clinical outcomes (mRS ≥ 4) are calculated. The hematoma size for prediction of CTA spot sign was also analyzed. Results Only the spot sign on dCTA could predict high risk of significant HE and poor clinical outcomes as on fpCTA ( P spot sign on fpCTA or dCTA in the absence of intraventricular and subarachnoid hemorrhage. Conclusion This study clarifies that dCTA imaging could improve predictive performance of CTA in primary ICH. Furthermore, the XY value is the best predictor for CTA spot sign.

  20. Preoperative cerebral aneurysm assessment by three-dimensional CT angiography. Feasibility of surgery without cerebral angiography

    International Nuclear Information System (INIS)

    Kashiwagi, Shiro; Yamashita, Katsuhiro; Kato, Shoichi; Ito, Haruhide; Kurokawa, Kensuke; Watanabe, Yutaka

    1999-01-01

    The purpose of this study is to assess the capability of three-dimensional CT angiography (3D-CTA) to replace conventional catheter angiography as a preoperative examination for unruptured intracranial aneurysms. A prospective study was designed to evaluate 18 patients with 20 unruptured intracranial aneurysms (13 middle cerebral artery aneurysms, 6 anterior communicating artery aneurysms, and 1 internal carotid posterior communicating artery aneurysm) who underwent surgery. There were 12 women and 6 men with the average age of 63 years old. All patients were initially diagnosed as having intracranial aneurysms by MR angiography, followed by 3D-CTA and conventional catheter angiography for confirmation. Three experienced neurosurgeons were in charge of the operations. One of the neurosurgeons (surgeon 1) was provided with only 3D-CTA as the preoperative radiological evaluation, while the others (surgeon 2 and 3) were given through assessments with MRA, 3D-CTA, and conventional angiography. Surgeon 1 carried out the operations under careful observation by the surgeons 2 and 3. Problems encountered by the surgeon 1 during surgery were recorded. Neck clipping in 19 aneurysms and dome wrapping in 1 were successfully accomplished. All patients were discharged without complication. Surgeries went smoothly in 16 aneurysms with 3D-CTA alone. Discrepancies between the 3D-CTA findings and microsurgical anatomy were noted in 4 aneurysms: the size of the neck was overestimated in 3 aneurysms, the relationships to parent arteries were obscure in 2 aneurysms, and a perforating artery problematic to neck clipping was missed in 1 aneurysms by 3D-CTA. The results of this study support the notion that 3D-CTA can replace conventional catheter angiography as preoperative examination in the majority of regular-sized anterior circulation aneurysms. Nevertheless, surgeons should recognize and be prepared for the fact that 3D-CTA can give false impression about the aneurysm neck and

  1. Rarity of isolated pulmonary embolism and acute aortic syndrome occurring outside of the field of view of dedicated coronary CT angiography

    International Nuclear Information System (INIS)

    Lee, Hwa Yeon; Song, In Sup; Yoo, Seung Min; Rho, Ji Young; Moon, Jae Youn; Kim, In Jai; Lim, Sang Wook; Sung, Jung Hoon; Cha, Dong Hun; White, Charles S.

    2011-01-01

    Background Although triple rule-out CT angiography (TRO) to simultaneously evaluate acute coronary syndrome (ACS), pulmonary embolism (PE), and acute aortic syndrome (AAS) is increasingly used in many institutions, TRO is inevitably associated with increased radiation exposure due to extended z-axis coverage compared with dedicated coronary CT angiography (DCTA). Purpose To determine the frequency of exclusion of findings of AAS, PE, and significant incidental non-cardiac pathology that may be the cause of acute chest pain when using a restricted DCTA field of view (FOV). Material and Methods We retrospectively reviewed CT images and charts of 103 patients with acute PE and 50 patients with AAS. Either non-ECG gated dedicated pulmonary or aortic CT angiography was performed using 16- or 64-slice multidetector CT (MDCT). We analyzed the incidence of isolated PE, AAS, or significant non-cardiac pathology outside of DCTA FOV (i.e. from tracheal carina to the base of heart). Results There were two cases of isolated PE (2/103, 1.9%) excluded from the FOV of DCTA. One case of PE was isolated to the subsegmental pulmonary artery in the posterior segment of the right upper lobe. In the second case, pulmonary embolism in the left main pulmonary artery was located out of the FOV of DCTA because the left main pulmonary artery was retracted upwardly by fibrotic scar in the left upper lobe due to prior tuberculosis. There was no case of AAS and significant non-cardiac pathology excluded from the FOV of DCTA. AAS (n = 50) consisted of penetrating atherosclerotic ulcer (n = 7), intramural hematoma (n = 5) and aortic dissection (n = 38). Conclusion As isolated PE, AAS, and significant non-cardiac pathology outside of the DCTA FOV rarely occur, DCTA may replace TRO in the evaluation of patients with non-specific acute chest pain and a low pre-test probability of PE or aortic dissection

  2. Opinion: the case for advertising pharmaceuticals direct to consumers.

    Science.gov (United States)

    Auton, Frank

    2009-07-01

    Direct-to-consumer advertising (DCTA) of prescription-only medicines is currently only permitted in the USA and New Zealand. While proponents of DCTA argue that it allows patients to make more informed choices about available treatment options, opponents claim that marketing inevitably presents a biased viewpoint of pharmaceutical products. Frank Auton, senior lecturer in marketing and business strategy at the University of Westminster, UK, presents his case in favor of advertising pharmaceuticals directly to patients.

  3. Rarity of isolated pulmonary embolism and acute aortic syndrome occurring outside of the field of view of dedicated coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hwa Yeon; Song, In Sup (Dept. of Diagnostic Radiology Chung-Ang Univ. College of Medicine, Seoul (Korea, Republic of)); Yoo, Seung Min; Rho, Ji Young (Dept. of Diagnostic Radiology CHA Medical Univ. Hospital, Bundang (Korea, Republic of)), email: smyoo68@hanmail.net; Moon, Jae Youn; Kim, In Jai; Lim, Sang Wook; Sung, Jung Hoon; Cha, Dong Hun (Dept. of Cardiology CHA Medical Univ. Hospital, Bundang (Korea, Republic of)); White, Charles S. (Dept. of Diagnostic Radiology Univ. of Maryland, Baltimore (United States))

    2011-05-15

    Background Although triple rule-out CT angiography (TRO) to simultaneously evaluate acute coronary syndrome (ACS), pulmonary embolism (PE), and acute aortic syndrome (AAS) is increasingly used in many institutions, TRO is inevitably associated with increased radiation exposure due to extended z-axis coverage compared with dedicated coronary CT angiography (DCTA). Purpose To determine the frequency of exclusion of findings of AAS, PE, and significant incidental non-cardiac pathology that may be the cause of acute chest pain when using a restricted DCTA field of view (FOV). Material and Methods We retrospectively reviewed CT images and charts of 103 patients with acute PE and 50 patients with AAS. Either non-ECG gated dedicated pulmonary or aortic CT angiography was performed using 16- or 64-slice multidetector CT (MDCT). We analyzed the incidence of isolated PE, AAS, or significant non-cardiac pathology outside of DCTA FOV (i.e. from tracheal carina to the base of heart). Results There were two cases of isolated PE (2/103, 1.9%) excluded from the FOV of DCTA. One case of PE was isolated to the subsegmental pulmonary artery in the posterior segment of the right upper lobe. In the second case, pulmonary embolism in the left main pulmonary artery was located out of the FOV of DCTA because the left main pulmonary artery was retracted upwardly by fibrotic scar in the left upper lobe due to prior tuberculosis. There was no case of AAS and significant non-cardiac pathology excluded from the FOV of DCTA. AAS (n = 50) consisted of penetrating atherosclerotic ulcer (n = 7), intramural hematoma (n = 5) and aortic dissection (n = 38). Conclusion As isolated PE, AAS, and significant non-cardiac pathology outside of the DCTA FOV rarely occur, DCTA may replace TRO in the evaluation of patients with non-specific acute chest pain and a low pre-test probability of PE or aortic dissection

  4. 3D-CT angiography with ultrafast CT in the diagnosis of pulmonary thromboembolism

    International Nuclear Information System (INIS)

    Kuribayashi, Sachio; Hamada, Seiki; Takamiya, Makoto; Imakita, Satoshi; Yamada, Naoaki; Takase, Kei; Iino, Misako; Nakanishi, Norifumi

    1995-01-01

    The usefulness of 3D-CT angiography (3D-CTA) with ultrafast CT (UFCT) in the diagnosis of pulmonary thromboembolism (PTE) was evaluated. UFCT was carried out in 10 patients with PTE (acute: 5 cases, chronic: 5 cases) and one case with pulmonary artery thrombosis secondary to pulmonary hypertension with atrial septal defect. CT scanning was performed with Imatron C-100XL and C-150L. For the imaging, single-slice step volume scan mode was used with scan time of 100 msec and slice thickness of 6 mm. Contiguous axial images were obtained after contrast enhancement with slice interval of 6 mm. 3D-CTA was reconstructed from 2D-CT images with workstation, and was compared with pulmonary angiograms (PAG) or operative findings. The images of 3D-CTA had good quality and they were more useful than 2D-CT images in better understanding of the configuration and the extent of the thrombi. In comparison with PAG, 3D-CTA gave equivalent information in terms of central pulmonary emboli. Moreover, 3D-CTA had advantages over PAG in demonstrating both the blood lumen and the thrombus on the same image with capability of multi-directional displays. 3D-CTA with UFCT is the useful non-invasive imaging modality in the diagnosis of PTE. (author)

  5. Two-dimensional versus three-dimensional CT angiography in analysis of anatomical suitability for stentgraft repair of abdominal aortic aneurysms

    International Nuclear Information System (INIS)

    Pitoulias, Georgios A.; Aslanidou, Eleni A.; Papadimitriou, Dimitrios K.; Donas, Konstantinos P.; Schulte, Stefan

    2011-01-01

    Background The morphological analysis prior to endovascular abdominal aneurysm repair (EVAR) plays an important role in long-term outcomes. Post-imaging analysis of computed tomographic angiography (CTA) by three-dimensional reconstruction with central lumen line detection (CLL 3D-CTA) enables measurements to be made in orthogonal slices. This might be more precise than equal post-imaging analysis in axial slices by two-dimensional computed tomographic angiography (2D-CTA). Purpose To evaluate the intra- and interobserver variability of CLL 3D-CTA and 2D-CTA post-imaging analysis methods and the agreement between them in pre-EVAR suitability analysis of patients with abdominal aortic aneurysm (AAA). Material and Methods Anonymized CTA data-sets from 70 patients with AAA were analyzed retrospectively. Length measurements included proximal and distal aortic neck lengths and total distance from the lower renal artery to the higher iliac bifurcation. Width measurements included proximal and distal neck diameters, maximum AAA diameter and common iliac diameters just above the iliac bifurcations. The measurements were performed in random order by two vascular surgeons, twice per method with 1-month interval between readings. In the CLL 3D-CTA method we used semi-automated CLL detection by software and manual measurements on CTA slices perpendicular to CLL. The equal measurements in 2D-CTA were performed manually on axial CTA slices using a DICOM viewer workstation. The intra- and interobserver variability, as well as the agreement between the two methods were assessed by Bland-Altman test and bivariate correlation analysis. Results The intraobserver variability was significantly higher in 2D-CTA measurements for both readers. The interobserver variability was significant in 2D-CTA measurements of proximal neck dimensions while the agreement in CLL 3D-CTA analysis between the two readers was excellent in all studied parameters. The agreement between the two suitability

  6. Detection of intracranial aneurysms using multi-detector row CT 3D-angiography: comparison with operative findings

    Energy Technology Data Exchange (ETDEWEB)

    Han, You Mie; Lim, Soo Mee; Seo, Eui Kyo; Kim, Yoo Kyung [Mokdong Hospital, Ewha Womans University, Seoul (Korea, Republic of)

    2006-04-15

    To assess the efficacy of three-dimensional CT angiography (3D-CTA) using multi-detector row computed tomography (MDCT) in the evaluation of intracranial aneurysms in patients with non-traumatic acute subarachnoid hemorrhage and to describe those aneurysms which were not found 3D-CTA. 3D-CTA was done in 40 patients with non-traumatic subarachnoid hemorrhage by using a 16-slice MDCT; conventional digital subtraction angiography (DSA) was done in 36 of those patients within 12 hours. The CT and DSA images were reviewed by two radiologists and the site, size and neck of the aneurysms were evaluated. The results from these two modalities were then compared with the operative findings. We calculated the detection rates by 3D-CTA and DSA and evaluated the size differences of aneurysms diagnosed with 3D-DTA and those found at surgery. We also analyzed the locations and sizes of aneurysms missed by 3D-CTA and attempted to explain these false negatives. A total of 55 aneurysms were surgically confirmed in 40 patients. 48 of these were detected pre-operatively by 3D-CTA. Thus, the detection rate by 3D-CTA was 87%. The size difference of aneurysms as calculated by 3-D CTA and found operatively was as follows: less than 1 mm in 17 cases, within 1-2 mm in 15 cases, and more than 2 mm in 16 cases. Seven aneurysms were not detected by 3D-CTA. The major cause of these missed aneurysms was their small size. The undetected aneurysms were less than 2 mm in size, except for 2 instances of PCoA aneurysms. One case was not detected due to difficult image evaluation. A possible explanation of the one remaining missed aneurysms was the filling of the aneurismal sac by thrombosis. Though there were some limitations in the detection of aneurysms, 3D-CTA using 16-channel MDCT may provide sufficient pre-operative information for the management of patients with intracranial aneurysms in cases of emergency operations or DSA-failure.

  7. Detection of intracranial aneurysms using multi-detector row CT 3D-angiography: comparison with operative findings

    International Nuclear Information System (INIS)

    Han, You Mie; Lim, Soo Mee; Seo, Eui Kyo; Kim, Yoo Kyung

    2006-01-01

    To assess the efficacy of three-dimensional CT angiography (3D-CTA) using multi-detector row computed tomography (MDCT) in the evaluation of intracranial aneurysms in patients with non-traumatic acute subarachnoid hemorrhage and to describe those aneurysms which were not found 3D-CTA. 3D-CTA was done in 40 patients with non-traumatic subarachnoid hemorrhage by using a 16-slice MDCT; conventional digital subtraction angiography (DSA) was done in 36 of those patients within 12 hours. The CT and DSA images were reviewed by two radiologists and the site, size and neck of the aneurysms were evaluated. The results from these two modalities were then compared with the operative findings. We calculated the detection rates by 3D-CTA and DSA and evaluated the size differences of aneurysms diagnosed with 3D-DTA and those found at surgery. We also analyzed the locations and sizes of aneurysms missed by 3D-CTA and attempted to explain these false negatives. A total of 55 aneurysms were surgically confirmed in 40 patients. 48 of these were detected pre-operatively by 3D-CTA. Thus, the detection rate by 3D-CTA was 87%. The size difference of aneurysms as calculated by 3-D CTA and found operatively was as follows: less than 1 mm in 17 cases, within 1-2 mm in 15 cases, and more than 2 mm in 16 cases. Seven aneurysms were not detected by 3D-CTA. The major cause of these missed aneurysms was their small size. The undetected aneurysms were less than 2 mm in size, except for 2 instances of PCoA aneurysms. One case was not detected due to difficult image evaluation. A possible explanation of the one remaining missed aneurysms was the filling of the aneurismal sac by thrombosis. Though there were some limitations in the detection of aneurysms, 3D-CTA using 16-channel MDCT may provide sufficient pre-operative information for the management of patients with intracranial aneurysms in cases of emergency operations or DSA-failure

  8. Helical CT scan for emergent patients with cerebrovascular diseases

    International Nuclear Information System (INIS)

    Matsumoto, Masato; Sato, Naoki; Nakano, Masayuki; Watanabe, Youichi; Kodama, Namio

    1995-01-01

    We studied 44 emergent patients with cerebrovascular diseases (18 cases of subarachnoid hemorrhage, 15 of occlusive lesions, 7 of intracerebral hematoma and 4 of suspected subarachnoid hemorrhage) using helical CT scan. The helical CT scan was performed with contrast medium at a rate of 3 ml/sec with a delay of 20 sec, and was carried out before conventional angiography. The reconstruction time of 3D-CTA was within 10 min. We were able to obtain findings for the lesion on 3D-CTA before those on conventional angiography. The 3D-CTA yielded excellent images of the vascular structures and anatomical relationships of the aneurysm, its neck and parent artery, and surrounding arteries. However, it proved difficult to visualize vessels of less than 1 mm in diameter, especially the perforating arteries. In occlusive diseases, the degree of stenosis depended on the changes in CT number threshold: at present, evaluations of the lesions should be made by conventional angiography. 3D-CTA using helical CT scan can thus be applied for emergent patients with cerebrovascular diseases. Surgical simulation images of 3D-CTA were especially useful at the time of operation. (author)

  9. Helical CT scan for emergent patients with cerebrovascular diseases

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Masato; Sato, Naoki; Nakano, Masayuki; Watanabe, Youichi; Kodama, Namio [Fukushima Medical Coll. (Japan)

    1995-08-01

    We studied 44 emergent patients with cerebrovascular diseases (18 cases of subarachnoid hemorrhage, 15 of occlusive lesions, 7 of intracerebral hematoma and 4 of suspected subarachnoid hemorrhage) using helical CT scan. The helical CT scan was performed with contrast medium at a rate of 3 ml/sec with a delay of 20 sec, and was carried out before conventional angiography. The reconstruction time of 3D-CTA was within 10 min. We were able to obtain findings for the lesion on 3D-CTA before those on conventional angiography. The 3D-CTA yielded excellent images of the vascular structures and anatomical relationships of the aneurysm, its neck and parent artery, and surrounding arteries. However, it proved difficult to visualize vessels of less than 1 mm in diameter, especially the perforating arteries. In occlusive diseases, the degree of stenosis depended on the changes in CT number threshold: at present, evaluations of the lesions should be made by conventional angiography. 3D-CTA using helical CT scan can thus be applied for emergent patients with cerebrovascular diseases. Surgical simulation images of 3D-CTA were especially useful at the time of operation. (author).

  10. Assessment of the usefulness of three-dimensional CT angiography after peripheral arterial bypass surgery

    International Nuclear Information System (INIS)

    Hayashi, Saihou; Sasaki, Masaru; Kawamoto, Jun

    1997-01-01

    Conventional CT and three-dimensional CT angiography (3D-CTA) were conducted after peripheral arterial bypass surgery on 17 patients (26 grafts) from October, 1994 to April, 1996. Seventeen grafts were patent. The following objectives were satisfied in these cases: 1. Prosthetic graft or saphenous vein was depicted by 3D-CTA, 2. The distal portion of the native artery was depicted by 3D-CTA, and 3. Opacification of the graft interior was recognized by transverse section of CT. Nine grafts were occluded but prosthetic grafts were depicted in 5 cases, and prosthetic grafts and the distal portions of native arteries in 3 cases. Opacification of the graft interior was not seen in any case. Achievement of the above three objectives was considered necessary to determine graft patency. (author)

  11. Noninvasive evaluation of cerebral arteriovenous malformations by 4D-CT angiography using 320-detector row CT

    International Nuclear Information System (INIS)

    Tajiri, H.; Jin, L.; Tsukiyama, M.; Suzuki, Y.; Sekine, S.; Shimizu, T.; Ohiwa, T.

    2012-01-01

    Full text: Objective: Four-dimensional computed tomography angiography (4D-CTA) is a new and promising technique in the diagnosis of patients with cerebral arteriovenous malformations (AVMs). The purpose of this retrospective study was to investigate the utility of 4D-CTA using whole-brain 320-detector row CT for assessing cerebral AVMs compared with conventional angiography (CA). Materials and methods: Participants included patients admitted to our institution from November 2010 to March 2012 due to cerebral AVMs who underwent both 4D-CTA and CA within 14 days. The diagnosis of AVM was finally confirmed by CA. Two readers reviewed 4D-CTA and CA under consensus regarding AVM detection rate and each component of the AVM (feeders, nidi, drainers) using a four-point grading scale (excellent=3, good=2, fair=1, poor=0), and the Spetzler-Martin (S-M) grade. Results: During the study period, 11 patients met the inclusion criteria. The average score for feeders, nidi, and drainers was 2.0, 2.3, and 2.5 in 4D-CTA and 2.4, 2.6, and 2.7 in CA, respectively. The average S-M grade score was 2.0 in all patients. There were no statistically significant differences between the two modalities (P<.005). Conclusion: 4D-CTA using 320-detector row CT is a very reliable method and offers diagnostic performance equivalent to CA for detecting and predicting S-M classification of cerebral AVMs.

  12. Comparative study of the ionic exchange of Ca++, Sr++, and Ba++ cations on resins and inorganic exchangers

    International Nuclear Information System (INIS)

    Sanchez Batanero, P.

    1969-03-01

    With a view to applying the results to certain problems related to chemical separations in activation analysis, a study has been made, of the possibilities of separating the alkaline-earth elements Ca, Sr and Ba on organic resins and inorganic exchangers using the radioactive indicator method. The partition coefficients of the cations Ca 2+ , Sr 2+ and Ba 2+ have been measured on Dowex 50 W (NH 4 + ) x 8 resin in the presence of EDTA - NTA - EGTA and DCTA as complexing agents, and on zirconium phosphate, tungstate and molybdate in the presence of HCl and NH 4 Cl. Methods have been developed for separating mixtures of alkaline-earth elements using DCTA-NH 4 + followed by elution on Dowex 50 W (NH 4 + ) x 8 resin columns and on zirconium phosphate. Amongst the complexing agents used on the ion-exchange resins the most promising appears to be DCTA which leads to partition coefficients Ca, Sr and Ba which are very different. The results of measurements of partition coefficients on zirconium phosphate (NH 4 + form) using DCTA-NH 4 + show the interesting possibilities of separations on columns. The separation of the alkaline-earth elements on zirconium phosphate seems to be less quantitative than on Dowex 50 resin; it is however much faster in the former case and this can be useful for treating short half-life radioisotopes in activation analysis. (author) [fr

  13. 76 FR 47638 - Petition for Waiver of Compliance

    Science.gov (United States)

    2011-08-05

    ... measures. DCTA submitted the first petition for relief (the ``Base Waiver'') in which it sought relief from..., 229.71, 229.135, and Appendix D--Criteria for Certification of Crashworthy Event Recorder Memory... in these proceedings by submitting written views, data, or comments. FRA does not anticipate...

  14. Comparative study of the ionic exchange of Ca{sup ++}, Sr{sup ++}, and Ba{sup ++} cations on resins and inorganic exchangers; Etude comparative de l'echange ionique des cations Ca{sup ++}, Sr{sup ++} et Ba{sup ++} sur resine et sur echangeurs mineraux

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Batanero, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-03-01

    With a view to applying the results to certain problems related to chemical separations in activation analysis, a study has been made, of the possibilities of separating the alkaline-earth elements Ca, Sr and Ba on organic resins and inorganic exchangers using the radioactive indicator method. The partition coefficients of the cations Ca{sup 2+}, Sr{sup 2+} and Ba{sup 2+} have been measured on Dowex 50 W (NH{sub 4}{sup +}) x 8 resin in the presence of EDTA - NTA - EGTA and DCTA as complexing agents, and on zirconium phosphate, tungstate and molybdate in the presence of HCl and NH{sub 4}Cl. Methods have been developed for separating mixtures of alkaline-earth elements using DCTA-NH{sub 4}{sup +} followed by elution on Dowex 50 W (NH{sub 4}{sup +}) x 8 resin columns and on zirconium phosphate. Amongst the complexing agents used on the ion-exchange resins the most promising appears to be DCTA which leads to partition coefficients Ca, Sr and Ba which are very different. The results of measurements of partition coefficients on zirconium phosphate (NH{sub 4}{sup +} form) using DCTA-NH{sub 4}{sup +} show the interesting possibilities of separations on columns. The separation of the alkaline-earth elements on zirconium phosphate seems to be less quantitative than on Dowex 50 resin; it is however much faster in the former case and this can be useful for treating short half-life radioisotopes in activation analysis. (author) [French] En vue de l'application a certains problemes de separations chimiques en analyse par activation, on a etudie les possibilites de separation des elements alcalino-terreux Ca-Sr et Ba sur resine organique et sur echangeurs mineraux par la methode des indicateurs radioactifs. Les coefficients de partage des cations Ca{sup +2}, Sr{sup +2} et Ba{sup +2} sur resine Dowex 50 W (NH{sub 4}{sup +}) x 8 en milieux complexants EDTA - NTA - EGTA et DCTA et sur phosphate, tungstate et molybdate de zirconium en milieu HCl et NH{sub 4}Cl ont ete mesures. Des

  15. Experimental results of a Mach 10 conical-flow derived waverider to 14-X hypersonic aerospace vehicle

    Directory of Open Access Journals (Sweden)

    Tiago Cavalcanti Rolim

    2011-05-01

    Full Text Available This paper presents a research in the development of the 14-X hypersonic airspace vehicle at Institute for Advanced Studies (IEAv from Department of Science and Aerospace Technology (DCTA of the Brazilian Air Force (FAB. The 14-X project objective is to develop a higher efficient satellite launch alternative, using a Supersonic Combustion Ramjet (SCRAMJET engine and waverider aerodynamics. For this development, the waverider technology is under investigation in Prof. Henry T. Nagamatsu Aerothermodynamics and Hypersonics Laboratory (LHTN, in IEAv/DCTA. The investigation has been conducted through ground test campaigns in Hypersonic Shock Tunnel T3. The 14-X Waverider Vehicle characteristic was verified in shock tunnel T3 where surface static pressures and pitot pressure for Mach number 10 were measured and, using Schlieren photographs Diagnostic Method, it was possible to identify a leading-edge attached shock wave in 14-X lower surface.

  16. Influence of heart rhythm, breathing and arm position during computed tomography scanning on the registration accuracy of electro anatomical map (EAM) images, left atrium three-dimensional computed tomography angiography images, and fluoroscopy time during ablation to treat atrial fibrillation

    International Nuclear Information System (INIS)

    Chono, Taiki; Shimoshige, Shinya; Yoshikawa, Kenta; Mizonobe, Kazuhusa; Ogura, Keishi

    2013-01-01

    In CARTOMERGE for treatment of atrial fibrillation (AF) by ablation, by integrating electro anatomical map (EAM) and left atrium three-dimensional computed tomography angiography (3D-CTA) images, identification of the ablation points is simplified and the procedure can be made carried out more rapidly. However, the influence that heart rhythm, breathing and arm position during CT scanning have on registration accuracy and fluoroscopy time is not clear. To clarify the influence on registration accuracy and fluoroscopy time of heart rhythm, breathing and arm position during CT scanning. The patients were CT-scanned during both sinus rhythm (SR) and AF in each study subject. We evaluated the registration accuracy of images reconstructed between the cardiac cycle and assessed the registration accuracy and fluoroscopy time of images obtained during inspiratory breath-hold, expiratory breath-hold and up and down position of the arm. Although the registration accuracy of the EAM image and left atrium 3D-CTA image showed a significant difference during SR, no significant difference was seen during AF. Expiratory breath-hold and down position of the arm resulted in the highest registration accuracy and the shortest fluoroscopy time. However, arm position had no significant effect on registration accuracy. Heart rhythm and breathing during CT scanning have a significant effect on the registration accuracy of EAM images, left atrium 3D-CTA images, and fluoroscopy time. (author)

  17. Postoperative three-dimensional CT angiography after cerebral aneurysm clipping with titanium clips: detection with single detector CT. Comparison with intra-arterial digital subtraction angiography

    International Nuclear Information System (INIS)

    Sakuma, I.; Tomura, N.; Kinouchi, H.; Takahashi, S.; Otani, T.; Watarai, J.; Mizoi, K.

    2006-01-01

    AIM: To assess the significance of three-dimensional computed tomography angiography (3D-CTA) in detecting remnant necks after cerebral aneurysm clipping. MATERIALS AND METHODS: A total of 59 patients (77 aneurysms) underwent surgery using titanium clips. Two blinded observers independently evaluated the presence of neck remnants on shaded-surface display (SSD) imaging, volume rendered (VR) imaging, and intra-arterial digital subtraction angiography (IADSA). RESULTS: Mean sensitivity and specificity for detecting neck remnants were 50.0 and 74.2% for SSD imaging, 61.5 and 82.8% for VR imaging, and 92.3 and 92.2% for IADSA, respectively. Receiver operating characteristic (ROC) analysis revealed excellent diagnostic performance for IADSA [mean area under ROC curve (Az)=0.97], and good diagnostic performance for 3D-CTA (Az=0.70 and 0.76 for SSD and VR, respectively). Specificity of VR was better than that SSD (p=0.082), however, there was no significant difference between them. CONCLUSION: Use of 3D-CTA techniques can facilitate postoperative evaluation

  18. Alkylperoxyl radical scavenging activity of red leaf lettuce (Lactuca sativa L.) phenolics.

    Science.gov (United States)

    Caldwell, Charles R

    2003-07-30

    Although lettuce may provide relatively low levels of antioxidative phytochemicals which may contribute to human health, lettuce leaf extracts in fact contained compounds with high specific peroxyl radical scavenging activities. After determining the extraction conditions that minimized phenolic oxidation and produced the highest oxygen radical absorbance capacity (ORAC) values, the phenolic compounds from red leaf lettuce were separated by reverse-phase high-performance liquid chromatography (HPLC). The primary phenolic compounds in the leaf tissue extracts were mono- and dicaffeoyltartaric acid (CTA and DCTA), mono- and dicaffeoylquinic acid (CQA and DCQA), quercetin 3-malonylglucoside (QMG), quercetin 3-glucoside (QG), cyanidin 3-malonylglucoside (CMG), and an unknown phenolic ester (UPE). Significant levels of DCQA were only found after wounding. Using the new fluorescein-based ORAC assay procedures, fractions from the HPLC analyses were assayed for peroxyl radical absorbance capacity. Using absorbance to estimate concentration, the decreasing order of contribution to the total ORAC value of an extract from wounded tissue was QMG > DCQA > CMG > DCTA > UPE > QG > CTA. The decreasing order of the specific peroxyl radical scavenging activities was CMG > QG > DCTA > DCQA > QMG > UPE > CQA > CTA. Since the concentrations of plant flavonoid and phenolic acid esters are sensitive to environmental factors, this information may be used to develop pre- and postharvest conditions which increase the dietary benefits of leaf lettuce.

  19. Usefulness of virtual endoscopy for evaluating the relationship between the neck of intracranial aneurysm and surrounding vessels

    International Nuclear Information System (INIS)

    Ikeda, Jota; Horie, Hitoshi; Ishikura, Reiichi; Ando, Kumiko; Morikawa, Tsutomu; Tominaga, Satoru; Nakao, Norio

    2000-01-01

    Application of three-dimensional CT virtual endoscopy for evaluation of the neck and surrounding vessels of intracranial aneurysms. 3D-CT virtual endoscopy (VE) is a reconstructed image using computer processing of 3D-CT images. We evaluated the usefulness of a virtual endoscopy to analyze the relationship between the neck of an intracranial aneurysm and the surrounding vessels. Eight cases with intracranial aneurysms underwent digital subtraction angiography (DSA) and enhanced CT with transarterial infusion of contrast media. 3D-CT angiogram (3D-CTA) and virtual endoscopic images were obtained from the CT image data sets using surface rendering method. The relationship between the neck of an intracranial aneurysm and the surrounding vessels was confirmed by operation or IVR. VE clearly visualized the neck and surrounding vessels in all cases. Operation/IVR findings agreed with the virtual endoscopic findings in all cases, but not with the DSA or 3D-CTA findings in 4 and 2 cases, respectively. 3D-CTA and virtual endoscopy clearly visualizes the relationship between cerebral aneurysms and surrounding vessels, which is useful for determining IVR procedures. (author)

  20. Preoperative assessment of vascular anatomy by multidetector computed tomography before laparoscopic colectomy for transverse colon cancer: report of a case.

    Science.gov (United States)

    Kawamoto, Aya; Inoue, Yasuhiro; Okigami, Masato; Yasuda, Hiromi; Okugawa, Yoshinaga; Hiro, Junichiro; Toiyama, Yuji; Tanaka, Koji; Uchida, Keiichi; Mohri, Yasuhiko; Kusunoki, Masato

    2015-02-01

    Although the safety of laparoscopic surgery for colon cancer has been reported in many randomized controlled trials, concerns about the difficulty of surgery for transverse colon cancer has not been fully resolved, mainly because of the variation in the vascular anatomy of mesenteric vessels, which leads to difficulty in determining the optimal operative procedure and the extent of lymph node dissection. We present the case of a patient with transverse colon cancer who underwent laparoscopic surgery after preoperative assessment using a combination of endoscopic clipping and three-dimensional computed tomography angiography (3DCTA). A 68-year-old man was diagnosed with transverse colon cancer, and laparoscopic surgery has been planned. 3DCTA showed right-middle and left-middle colic arteries arising independently from the superior mesenteric artery. The relationship between the clip and vessels showed that the right-middle colic artery was the feeding artery of the tumor. Operative findings were consistent with 3DCTA findings, and transverse colectomy with lymph node dissection was successfully performed.

  1. The value of whole-brain CT perfusion imaging and CT angiography using a 320-slice CT scanner in the diagnosis of MCI and AD patients

    International Nuclear Information System (INIS)

    Zhang, Bo; Gu, Guo-jun; Jiang, Hong; Guo, Yi; Shen, Xing; Li, Bo; Zhang, Wei

    2017-01-01

    To validate the value of whole-brain computed tomography perfusion (CTP) and CT angiography (CTA) in the diagnosis of mild cognitive impairment (MCI) and Alzheimer's disease (AD). Whole-brain CTP and four-dimensional CT angiography (4D-CTA) images were acquired in 30 MCI, 35 mild AD patients, 35 moderate AD patients, 30 severe AD patients and 50 normal controls (NC). Cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP), and correlation between CTP and 4D-CTA were analysed. Elevated CBF in the left frontal and temporal cortex was found in MCI compared with the NC group. However, TTP was increased in the left hippocampus in mild AD patients compared with NC. In moderate and severe AD patients, hypoperfusion was found in multiple brain areas compared with NC. Finally, we found that the extent of arterial stenosis was negatively correlated with CBF in partial cerebral cortex and hippocampus, and positively correlated with TTP in these areas of AD and MCI patients. Our findings suggest that whole-brain CTP and 4D-CTA could serve as a diagnostic modality in distinguishing MCI and AD, and predicting conversion from MCI based on TTP of left hippocampus. (orig.)

  2. The value of whole-brain CT perfusion imaging and CT angiography using a 320-slice CT scanner in the diagnosis of MCI and AD patients

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bo; Gu, Guo-jun; Jiang, Hong; Guo, Yi [Medical School of Tongji University, Department of Medical Imaging, Tongji Hospital, Shanghai (China); Shen, Xing [Traditional Chinese Hospital, Department of Radiology, Kun Shan, Jiangsu Province (China); Li, Bo; Zhang, Wei [Medical School of Jiaotong University, Department of Medical Imaging, Renji Hospital, Shanghai (China)

    2017-11-15

    To validate the value of whole-brain computed tomography perfusion (CTP) and CT angiography (CTA) in the diagnosis of mild cognitive impairment (MCI) and Alzheimer's disease (AD). Whole-brain CTP and four-dimensional CT angiography (4D-CTA) images were acquired in 30 MCI, 35 mild AD patients, 35 moderate AD patients, 30 severe AD patients and 50 normal controls (NC). Cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP), and correlation between CTP and 4D-CTA were analysed. Elevated CBF in the left frontal and temporal cortex was found in MCI compared with the NC group. However, TTP was increased in the left hippocampus in mild AD patients compared with NC. In moderate and severe AD patients, hypoperfusion was found in multiple brain areas compared with NC. Finally, we found that the extent of arterial stenosis was negatively correlated with CBF in partial cerebral cortex and hippocampus, and positively correlated with TTP in these areas of AD and MCI patients. Our findings suggest that whole-brain CTP and 4D-CTA could serve as a diagnostic modality in distinguishing MCI and AD, and predicting conversion from MCI based on TTP of left hippocampus. (orig.)

  3. Dichorionic triamniotic triplet pregnancy complicated by twin anemia polycythemia sequence: the place of fetal therapy.

    Science.gov (United States)

    Griersmith, Thérèse H; Fung, Alison M; Walker, Susan P

    2014-12-01

    Monochorionic twins as part of a high order multiple pregnancy can be an unintended consequence of the increasingly common practice of blastocyst transfer for couples requiring in vitro fertilisation (IVF) for infertility. Dichorionic triamniotic (DCTA) triplets is the most common presentation, and these pregnancies are particularly high risk because of the additional risks associated with monochorionicity. Surveillance for twin-to-twin transfusion syndrome, including twin anemia polycythemia sequence, may be more difficult, and any intervention to treat the monochorionic pair needs to balance the proposed benefits against the risks posed to the unaffected singleton. Counseling of families with DCTA triplets is therefore complex. Here, we report a case of DCTA triplets, where the pregnancy was complicated by threatened preterm labour, and twin anemia polycythemia sequence (TAPS) was later diagnosed at 28 weeks. The TAPS was managed with a single intraperitoneal transfusion, enabling safe prolongation of the pregnancy for over 2 weeks until recurrence of TAPS and preterm labour supervened. Postnatal TAPS was confirmed, and all three infants were later discharged home at term corrected age, and were normal at follow-up. This case highlights that in utero therapy has an important role in multiple pregnancies of mixed chorionicity, and can achieve safe prolongation of pregnancy at critical gestations.

  4. Preliminary evaluation of 3D TOF MRA fly-around advantages in the diagnosis of internal carotid artery aneurysms

    International Nuclear Information System (INIS)

    Zhu Yusen; Zhang Lina; Xu Ke; Li Songbai; Huang Yanling; Sun Wenge; Jin Anyu; Qi Xixun; Li Yanliang

    2004-01-01

    Objective: To assess the advantages and the clinical application value of 3D TOF MR angiography fly-around in diagnosing internal carotid artery aneurysms in comparison with multi-slice helical CT three dimensional angiography (MS 3D-CTA) and digital subtraction angiography (DSA). Methods: Eighteen patients with clinical suspected internal carotid artery aneurysms were involved in the study. There were 4 males and 14 females, and their age ranged from 17 to 76 years. 14 patients were with subarachnoid hemorrhage and 4 patients with oculomotor nerve palsy. All these patients underwent 3D TOF MRA and MS 3D-CTA, and 17 patients underwent DSA. All of them accepted operation treatment. 3D TOF MRA was performed with Toshiba 1.5 T MRI system and the parameters of 3D-TOF sequence were: TR 30 ms, TE 6.8 ms, field of view 17 cm x 19 cm, matrix 160 x 256, slab thickness 50-60 mm, section thickness 1.2 mm, flip angle 20 degree. Row data of MS 3D-CTA was acquired by Multi-slice helical CT-Aquilion (Toshiba). The scanning parameters were: image slice thickness 1.0 mm, scan speed 0.5 s/r, helical pitch 3.5, delay time 15-18 sec. Nonionic contrast agent was injected intravenously (2.0 ml/kg) at the speed of 4.0-5.0 ml/s using a power injector. Source images of 3D TOF MRA and MS 3D-CTA were processed into MIP and fly-around using a workstation SGI-O2, with the post-processing software Alatoview (Ver: 1.42). Conventional four-vessel digital subtraction angiography was performed with Siemens Multi-Start OT. Results: 22 aneurysms were detected by both 3D TOF MRA and MS 3D-CTA (1 ACA aneurysm, 3 ACoMA aneurysms, 1 left MCA aneurysm, 2 ICA-cavernous aneurysms, 3 left ICA-PCoM aneurysms, 8 right ICA-PCoM aneurysms, 1 left ICA-AChA aneurysms, 2 right ICA-AChA aneurysms, and 1 superior pituitary artery aneurysm). Among those aneurysms, one was not detected by DSA, and another aneurysm's neck was not clear on the image of DSA. 1 right ICA-PCoM aneurysm was surgically treated according to 3D

  5. Primitive experience of three dimensional multi-slice spiral CT angiography for the follow-up of intracranial aneurysm clipping

    International Nuclear Information System (INIS)

    Yang Yunjun; Chen Weijian; Hu Zhangyong; Wu Enfu; Wang Meihao; Zhuge Qichuan; Zhongming; Cheng Jingliang; Ren Cuiping; Zhang Yong

    2008-01-01

    Objective To evaluate multi-slice three-dimensional CT angiography (MS 3D-CTA) for the follow-up of intracranial aneurysm clipping. Methods: MS 3D-CTA of 16 patients with intracranial aneurysm clipping were retrospectively analyzed. The patients were scanned on a 16-slice spiral CT (GE Lightspeed pro). Volume rendering(VR), thin maximum intensity projection(thin MIP) and multi-planar reconstruction (MPR) were employed in image postprocessing in all cases. Results: There were 17 clips in the 16 patients with aneurysm clipping. Six clips were located at the posterior communicating artery, 5 at the anterior communicating artery, 4 at the middle cerebral artery, and the remaining 2 clips were located at the pericallosal artery, in 1 patient. There were no abnormalities found in the aneurysm clipping region in 7 cases by MS 3D- CTA. There were residual aneurysm in 2 cases, parent artery stenosis in 4 cases, and artery spasm in 3 eases. There was no parent artery occlusion and clip displacement in all cases. VR showed excellent 3D spacial relations between the clip and parent artery in 12 cases, and showed good relations in 3 cases. The 1 case with 2 clips in the pericallosal artery showed heavy beam-hardening artifacts. The size and shape of aneurysm clips were clearly depicted by MPR and thin MIP, while 3D spacial relation of aneurysm clip and parent artery were poorly showed. Conclusion: MS 3D-CTA is a safe and efficient method for the follow-up of intracranialaneurysm clipping. Combined VR with MPR or thin MIP can well reveal postoperative changes after aneurysm clipping. (authors)

  6. Preoperative evaluation of renal anatomy and renal masses with helical CT, 3D-CT and 3D-CT angiography.

    Science.gov (United States)

    Toprak, Uğur; Erdoğan, Aysun; Gülbay, Mutlu; Karademir, Mehmet Alp; Paşaoğlu, Eşref; Akar, Okkeş Emrah

    2005-03-01

    The aim of this prospective study was to determine the efficacy of three-dimensional computed tomography (3D-CT) and three-dimensional computed tomographic angiography (3D-CTA) that were reconstructed by using the axial images of the multiphasic helical CT in the preoperative evaluation of renal masses and demonstration of renal anatomy. Twenty patients that were suspected of having renal masses upon initial physical examination and ultrasonographic evaluation were examined through multiphasic helical CT. Two authors executed CT evaluations. Axial images were first examined and then used to reconstruct 3D-CT and 3D- CTA images. Number, location and size of the renal masses and other findings were noted. Renal vascularization and relationships of the renal masses with the neighboring renal structures were further investigated with 3D-CT and 3D-CTA images. Out of 20 patients, 13 had histopathologically proven renal cell carcinoma. The diagnoses of the remaining seven patients were xanthogranulomatous pyelonephritis, abscess, simple cyst, infected cyst, angiomyolipoma, oncocytoma and arteriovenous fistula. In the renal cell carcinoma group, 3 patients had stage I, 7 patients had stage II, and 3 patients had stage III disease. Sizes of renal cell carcinoma masses were between 23 mm to 60 mm (mean, 36 mm). Vascular invasion was shown in 2 renal cell carcinoma patients. Collecting system invasion was identified in 11 of 13 renal cell patients. These radiologic findings were confirmed with surgical specimens. Three-dimensional CT and 3D-CTA are non-invasive, effective imaging techniques for the preoperative evaluation of renal masses.

  7. Management of subarachnoid hemorrhage classified grade V. Possibility of intravascular treatment

    Energy Technology Data Exchange (ETDEWEB)

    Uzura, Masahiko; Oshima, Kousuke; Morishima, Hiroyuki; Uchida, Kazuyoshi; Watanabe, Hiroyuki; Nakamura, Homare; Tanaka, Katsuyuki; Sekino, Hiroaki; Akashi, Katsuya [St. Marianna Univ., Kawasaki, Kanagawa (Japan). School of Medicine

    2001-10-01

    Management outcomes in poor-grade patients (World Federation of Neurological Surgeons Committee on a Universal Subarachnoid Hemorrhage Grading Scale Grade V) with ruptured cerebral aneurysms have historically been unsatisfactory. In the present study, we examined the possibility of intravascular treatment for ruptured aneurysm detected by 3-Dimensional CT angiography (3D-CTA) in poor-grade SAH patients. From April 1997 to July 2000, 3D-CTA was performed on 54 of 73 patients admitted with Grade V subarachnoid hemorrhage (SAH). Excluding 3 patients who underwent emergency surgery for ruptured aneurysms and intracerebral hematomas, CT findings from the remaining 51 patients were analyzed. The study included 23 men and 28 women, ranging in age from 28 to 91 with an average age of 63.6. The patients' initial scores on the Glasgow Coma Scale upon admission were 3 in 36 patients (including 19 patients who had undergone cardio-pulmonary arrest), 4 in 11 patients, 5 in 2 patients, and 6 in 2 patients. Ruptured aneurysms responsible for SAH were clearly delineated in 41 aneurysms from 39 patients, with 32 aneurysms in the anterior circulation and 9 in the posterior circulation. Patients with Glasgow Coma Scale of 4 or higher whose score did not progressively decrease for 12 hours after symptom onset were considered for intravascular treatment. In our study, 4 of 39 patients (10.3%) met these criteria. Glasgow Outcome Scale results were good recovery in 1 case, moderate disability in 1 case, severe disability in 1 case, and death in the remaining 48 cases. These results suggest that the management course for poor-grade (WFNS Grade V) SAH patients who retain brain stem reflexes contain the following: identification of aneurysms by 3D-CTA, maintenance of adequate sedation and external drainage to treat acute hydrocephalus, continued minimum 12-hour observation, monitoring levels of consciousness where possible, and consideration of aggressive therapy including

  8. The Role of Bone Subtraction Computed Tomographic Angiography in Determining Intracranial Aneurysms in Non-Traumatic Subarachnoid Hemorrhage

    International Nuclear Information System (INIS)

    Kayhan, Aysegul; Koc, Osman; Keskin, Suat; Keskin, Fatih

    2014-01-01

    The presence of blood in the subarachnoid space is an acute pathology with a serious risk of death and complications. The most common etiology (approximately 80%) is intracranial aneurysm. The aim of this study was to assess the role of bone subtracted computed tomographic angiography (BSCTA), a novel and noninvasive method for determining and characterizing intracranial aneurysms. Sixty consecutive patients with clinically suspected non-traumatic subarachnoid hemorrhage (SAH) were considered to enter the study. The subtraction quality was inadequate in ten patients; thus, they were excluded, leaving 50 patients (84.4%) in the study. Bone subtracted and non-subtracted 3D images were obtained from the BSCTA raw data sets. All images obtained by digital subtraction angiography (DSA), BSCTA, and computed tomographic angiography (CTA) were evaluated for the presence or absence of an aneurysm and the location, minimal sac diameter, and neck size ratio of the aneurysm. DSA was considered as the gold standard during the evaluation of the data. Of the 50 patients who participated in this study, 11 had no aneurysms as determined by both CTA and DSA. Examination of the remaining 39 patients revealed the presence of 51 aneurysms. While 3D-CTA could not detect six aneurysms that were located in the base of the skull, 3D-BSCTA easily detected them. Moreover, five aneurysms were only partially detected by 3D-CTA. According to this data, the sensitivity of 3D-BSCTA and 3D-CTA was calculated as 98% and 86.3%, respectively; the specificity was calculated as 100% and 90.9%, respectively, per aneurysm; and the sensitivity of 100% for 3D-BSCTA and 98% for 3D-CTA was achieved by using combined images with multi-planar reconstruction (MPR) and maximum intensity projection (MIP). BSCTA detected and characterized the aneurysms as well as DSA, and BSCTA and DSA gave concordant results in detecting aneurysms. BSCTA is easily accessible, less time consuming, and most importantly, a non

  9. The Role of Bone Subtraction Computed Tomographic Angiography in Determining Intracranial Aneurysms in Non-Traumatic Subarachnoid Hemorrhage

    Science.gov (United States)

    Kayhan, Aysegul; Koc, Osman; Keskin, Suat; Keskin, Fatih

    2014-01-01

    Background: The presence of blood in the subarachnoid space is an acute pathology with a serious risk of death and complications. The most common etiology (approximately 80%) is intracranial aneurysm. Objectives: The aim of this study was to assess the role of bone subtracted computed tomographic angiography (BSCTA), a novel and noninvasive method for determining and characterizing intracranial aneurysms. Patients and Methods: Sixty consecutive patients with clinically suspected non-traumatic subarachnoid hemorrhage (SAH) were considered to enter the study. The subtraction quality was inadequate in ten patients; thus, they were excluded, leaving 50 patients (84.4%) in the study. Bone subtracted and non-subtracted 3D images were obtained from the BSCTA raw data sets. All images obtained by digital subtraction angiography (DSA), BSCTA, and computed tomographic angiography (CTA) were evaluated for the presence or absence of an aneurysm and the location, minimal sac diameter, and neck size ratio of the aneurysm. DSA was considered as the gold standard during the evaluation of the data. Results: Of the 50 patients who participated in this study, 11 had no aneurysms as determined by both CTA and DSA. Examination of the remaining 39 patients revealed the presence of 51 aneurysms. While 3D-CTA could not detect six aneurysms that were located in the base of the skull, 3D-BSCTA easily detected them. Moreover, five aneurysms were only partially detected by 3D-CTA. According to this data, the sensitivity of 3D-BSCTA and 3D-CTA was calculated as 98% and 86.3%, respectively; the specificity was calculated as 100% and 90.9%, respectively, per aneurysm; and the sensitivity of 100% for 3D-BSCTA and 98% for 3D-CTA was achieved by using combined images with multi-planar reconstruction (MPR) and maximum intensity projection (MIP). BSCTA detected and characterized the aneurysms as well as DSA, and BSCTA and DSA gave concordant results in detecting aneurysms. Conclusions: BSCTA is

  10. HF effect on dissociation kinetics of plutonium and neptunium complexes with 1,2-diaminocyclohexanetetraacetic acid in nitric acid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Nikitina, S.A.; Stepanov, A.V.

    1982-01-01

    Dissociation kinetics of Pusup((4)) and Np sup((4)) complexes with DCTA were investigated in HNO/sub 3/ solutions in the presence of HF and arsenazo 3. It was found that HF or NaF produced a differentiating effect on the reactivity of the complexes at (HNO/sub 3/)=1-6 mol/l as well as inhibiting effect at (HNO/sub 3/)=0.01 mol/l. Conditions of the differential kinetic analysis of plutonium and neptunium in the mixture and differential spectrophotometric analysis of uranium (6) during the camouflage of neptunium (4) and plutonium (4) were determined.

  11. HF effect on dissociation kinetics of plutonium and neptunium complexes with 1,2-diaminocyclohexanetetraacetic acid in nitric acid solutions

    International Nuclear Information System (INIS)

    Nikitina, S.A.; Stepanov, A.V.

    1982-01-01

    Dissociation kinetics of Pusup((4)) and Np sup((4)) complexes with DCTA were investigated in HNO 3 solutions in the presence of HF and arsenazo 3. It was found that HF or NaF produced a differentiating effect on the reactivity of the complexes at [HNO 3 ]=1-6 mol/l as well as inhibiting effect at [HNO 3 ]=0.01 mol/l. Conditions of the differential kinetic analysis of plutonium and neptunium in the mixture and differential spectrophotometric analysis of uranium (6) during the camouflage of neptunium (4) and plutonium (4) were determined

  12. Preoperative evaluation of the abdominal aortic aneurysm using spiral CT

    International Nuclear Information System (INIS)

    Chisuwa, Hisanao; Nishimaki, Keiji; Arai, Masayuki; Honda, Haruyasu; Urata, Koichi; Miyagawa, Yusuke; Makuuchi, Masatoshi; Shimizu, Mikio; Okamoto, Kohei.

    1995-01-01

    Six patients with abdominal aortic aneurysm (AAA) were studied with three-dimensionally reconstructed CT angiography (3D-CTA) in order to evaluate its usefulness as a diagnostic tool for vascular surgery patients. Images of the intravenously contrasted abdominal aorta were obtained with spiral scan during a single breath hold. The images of the abdominal aorta and its major branches were three-dimensionally reconstructed with a shaded surface display mode. The three-dimensional image reconstruction was successful in all the six cases and performed without difficulties. Shaded surface display presented a deficit to depict the aortic wall with mural thrombus. However, multidirectional display of the abdominal aorta and its branches facilitated interpretation of the anatomical details of the lesions and planning of surgical repair. 3D-CTA is an alternative to conventional aortography for preoperative diagnosis of AAA. Moreover it was shown to be noninvasive, easy to proceed. It presented good angiographical resolution that can be used as a precise diagnostic tool in vascular surgery. (author)

  13. Clinical application of three-dimensional spiral CT cerebral angiography with volume rendering

    International Nuclear Information System (INIS)

    Duan Shaoyin; Huang Xi'en; Kang Jianghe; Zhang Dantong; Lin Qingchi; Cai Guoxiang; Xu Meixin; Pang Ruilin

    2002-01-01

    Objective: To study the methodology and assess the clinical value of three-dimensional CT angiography (3D-CTA) with volume rendering (VR) in cerebral vessels. Methods: Sixty-two patients were examined by means of 3D-CTA with volume rendering. VR was used in the reconstruction of 3D images, and the demonstration of normal vessels and vascular lesions were particularly analyzed. At the same time, comparisons were made between the images of VR and SSD, MIP, and also between the diagnosis of VR-CTA and DSA or postoperative results. Results: In VR images, cerebral vessel routes and vessel cavities were showed clearly, while the relationship among vascular lesions, surrounding vessels, and neighboring structure was distinguished. 50 cases (80.6%) were found positive, 48 of which were correct and 2 were false-positive compared with DSA or postoperative results. The accurate rate of diagnosis was 96.0%. There was no obvious difference in showing the cerebral vessel among the images of VR, SSD and MIP (P > 0.25). Conclusion: Three-dimensional CT cerebral angiography with VR is a new noninvasive effective method. It can even partly replace the DSA. The 3D-images have the characteristics of showing the cerebral vascular cavity and overlapped vessels without cutting the skull

  14. Abnormal course of the vertebral artery at the craniovertebral junction in patients with Down syndrome visualized by three-dimensional CT angiography

    International Nuclear Information System (INIS)

    Yamazaki, Masashi; Okawa, Akihiko; Hashimoto, Mitsuhiro; Aiba, Atsuomi; Someya, Yukio; Koda, Masao

    2008-01-01

    We determined the incidence of vertebral artery (VA) anomalies at the craniovertebral junction (CVJ) in patients with Down syndrome, and characterized the VA anomalies. The course of the VA in 46 consecutive patients who were due to undergo posterior arthrodesis surgery at the CVJ were evaluated by three-dimensional CT angiography (3DCTA). Included were five patients with Down syndrome who suffered from myelopathy due to atlantoaxial subluxation. All five patients with Down syndrome also had a simultaneous congenital skeletal anomaly, either os odontoideum or ossiculum terminale. Of the five patients with Down syndrome, three had VA anomalies at the CVJ, two had fenestration and one had a persistent first intersegmental artery. Of the other 41 patients without Down syndrome, five had VA anomalies at the CVJ. The incidence of VA anomalies at the CVJ was much higher in patients with Down syndrome than in those without Down syndrome. In planning surgery in patients with Down syndrome with symptomatic atlantoaxial subluxation and a congenital skeletal anomaly at the CVJ, we should consider the possible presence of VA anomalies. Preoperative 3DCTA allows us to precisely identify an anomalous VA and evaluate the possible risk of intraoperative VA injury in advance. (orig.)

  15. Abnormal course of the vertebral artery at the craniovertebral junction in patients with Down syndrome visualized by three-dimensional CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Masashi; Okawa, Akihiko; Hashimoto, Mitsuhiro; Aiba, Atsuomi; Someya, Yukio; Koda, Masao [Chiba University Graduate School of Medicine, Spine Section, Department of Orthopaedic Surgery, Chiba (Japan)

    2008-06-15

    We determined the incidence of vertebral artery (VA) anomalies at the craniovertebral junction (CVJ) in patients with Down syndrome, and characterized the VA anomalies. The course of the VA in 46 consecutive patients who were due to undergo posterior arthrodesis surgery at the CVJ were evaluated by three-dimensional CT angiography (3DCTA). Included were five patients with Down syndrome who suffered from myelopathy due to atlantoaxial subluxation. All five patients with Down syndrome also had a simultaneous congenital skeletal anomaly, either os odontoideum or ossiculum terminale. Of the five patients with Down syndrome, three had VA anomalies at the CVJ, two had fenestration and one had a persistent first intersegmental artery. Of the other 41 patients without Down syndrome, five had VA anomalies at the CVJ. The incidence of VA anomalies at the CVJ was much higher in patients with Down syndrome than in those without Down syndrome. In planning surgery in patients with Down syndrome with symptomatic atlantoaxial subluxation and a congenital skeletal anomaly at the CVJ, we should consider the possible presence of VA anomalies. Preoperative 3DCTA allows us to precisely identify an anomalous VA and evaluate the possible risk of intraoperative VA injury in advance. (orig.)

  16. Extraction of rare earth elements with organophosphorus extractants as carriers in supported liquid membranes

    International Nuclear Information System (INIS)

    Kopunec, R.; Benitez, J.C.

    1991-01-01

    The membrane extraction of Y, Ce, Eu, Tm and their binary mixtures Ce-Y, Ce-Eu, Ce-Tm with supported liquid membranes containing TBP and HDEHP as carriers in decane-dodecane hydrocarbon solvent, has been studied. Upon extraction with TBP aqueous nitrate solutions of rare earth elements (REE) were used as feed phase. In some cases they also contained EDTA or DCTA. In most cases, the receiving phase was an aqueous solution of EDTA. Extraction with HDEHP was performed from nitrate and chloride solutions and the receiving phase was the corresponding dilute acid. Pertraction of an element through a membrane was studied as a function of time and of initial composition of phases. The results are presented in the following forms: flux of metal through membrane, coefficients of permeability, separation factors and effective diffusion coefficients. (author) 24 refs.; 8 figs.; 3 tabs

  17. Antimicrobial activity of Lactobacillus and Bifidobacterium strains against pathogenic microorganisms “in vitro”Atividade antimicrobiana de Lactobacillus e Bifodobacterium frente a microrganismos patogênicos “in vitro”

    Directory of Open Access Journals (Sweden)

    Giselle Nobre Costa

    2012-10-01

    Full Text Available Lactobacilli and bifidobacteria have a long history of safe use in foods. These bacteria have biotechnological characteristics of interest such as the inhibition of pathogens. In this work, two lactobacilli strain and a bifidobacterium strain isolated from human gut were evaluated concerning to their ability to inhibit pathogenic microorganisms in foods by diffusion agar tests. Moreover, we assessed the metabolites produced in culture broth under static and shaking growth to simulate anaerobiosis and aerobiosis conditions, respectively. L. acidophilus LA5, L. plantarum DCTA 8420 and B. lactis DCTA 8724 showed ability to inhibit S. aureus FRI 196, strains producer toxins A and D, as well as B. cereus ATCC 25923, E. coli ATCC 25922 and S. Enteritidis, whose inhibition halos reached, on average, 24 mm in diameter. In the agar diffusion method with concentrated culture medium, it was possible to observe the effect of oxygen on the production of toxic substances. This result showed that cultivation of Lactobacillus under aerobic conditions seems to exert greater inhibitory effect, whereas for Bifidobacterium strain the effect was the opposite.Lactobacilos e bifidobactérias apresentam um longo histórico de uso seguro em alimentos, além de apresentarem características de interesse biotecnológico como a inibição de patógenos. Neste trabalho duas linhagens de lactobacilos e uma de bifidobactéria, isoladas do intestino humano, foram avaliadas em testes de difusão em ágar, quanto à capacidade de inibição de microrganismos patogênicos de ocorrência comuns em toxinfecções alimentares. Adicionalmente, foram avaliados os metabólitos produzidos em caldo de cultivo estático e em agitação para simular condições de anaerobiose a aerobiose, respectivamente. As três bactérias, L. acidophilus LA5, L. plantarum DCTA 8420 e B. lactis DCTA 8724 apresentaram capacidade de inibição para S. aureus FRI 196 linhagem produtora de toxinas A e D

  18. Increase of Intracellular Cyclic AMP by PDE4 Inhibitors Affects HepG2 Cell Cycle Progression and Survival.

    Science.gov (United States)

    Massimi, Mara; Cardarelli, Silvia; Galli, Francesca; Giardi, Maria Federica; Ragusa, Federica; Panera, Nadia; Cinque, Benedetta; Cifone, Maria Grazia; Biagioni, Stefano; Giorgi, Mauro

    2017-06-01

    Type 4 cyclic nucleotide phosphodiesterases (PDE4) are major members of a superfamily of enzymes (PDE) involved in modulation of intracellular signaling mediated by cAMP. Broadly expressed in most human tissues and present in large amounts in the liver, PDEs have in the last decade been key therapeutic targets for several inflammatory diseases. Recently, a significant body of work has underscored their involvement in different kinds of cancer, but with no attention paid to liver cancer. The present study investigated the effects of two PDE4 inhibitors, rolipram and DC-TA-46, on the growth of human hepatoma HepG2 cells. Treatment with these inhibitors caused a marked increase of intracellular cAMP level and a dose- and time-dependent effect on cell growth. The concentrations of inhibitors that halved cell proliferation to about 50% were used for cell cycle experiments. Rolipram (10 μM) and DC-TA-46 (0.5 μM) produced a decrease of cyclin expression, in particular of cyclin A, as well as an increase in p21, p27 and p53, as evaluated by Western blot analysis. Changes in the intracellular localization of cyclin D1 were also observed after treatments. In addition, both inhibitors caused apoptosis, as demonstrated by an Annexin-V cytofluorimetric assay and analysis of caspase-3/7 activity. Results demonstrated that treatment with PDE4 inhibitors affected HepG2 cell cycle and survival, suggesting that they might be useful as potential adjuvant, chemotherapeutic or chemopreventive agents in hepatocellular carcinoma. J. Cell. Biochem. 118: 1401-1411, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Towards understanding work-as-done in air traffic management safety assessment and design

    International Nuclear Information System (INIS)

    Woltjer, Rogier; Pinska-Chauvin, Ella; Laursen, Tom; Josefsson, Billy

    2015-01-01

    This paper describes the approach taken and the results to develop guidance, to include Resilience Engineering principles in methodology for safety assessment of functional changes, in Air Traffic Management (ATM). It summarizes the process of deriving resilience principles for ATM, originating from Resilience Engineering concepts and transposed into ATM operations. These principles are the foundation for guidance material incorporating Resilience Engineering (RE) concepts into safety assessment methodology. The guidance material provides a method using workshops generating qualitative descriptions of RE principles applied to ATM services of everyday work, as done currently and as envisioned after introduction of a new technology or way of working. The guidance material has been proposed as part of the safety assessment methodology of SESAR (Single European Sky ATM Research), and as stand-alone guidance for ATM design processes. The methodology was validated via a test case on the i4D/CTA (Controlled Time of Arrival) concept. Operational examples from the application of the developed guidance to the i4D/CTA concept are provided. Initial evaluation of the guidance suggests that the methodology (1) provides a narrative, vocabulary and documentation means of project discussions on resilience; (2) brings the discussions of safety and resilience closer to operational practice; (3) facilitates a broader systemic and integrative perspective on operational, management, business, safety, environmental, and human performance aspects; and (4) can extend the vocabulary of safety assessment to include the description of emergent properties, to better support functional changes in ATM. - Highlights: • Guidance material for safety assessment based on systemic thinking is proposed. • It operationalizes Resilience Engineering principles in Air Traffic Management, including a case study. • It enables description of expected changes in work-as-done when introducing a new

  20. chemical studies on the extraction of certain metal ions from aqueous solution by liquid emulsion membrane

    International Nuclear Information System (INIS)

    Kassem, A.T.

    2011-01-01

    In this thesis four systems are addressed related to the use of liquid emulsion membranes (ELM) based on Co(III)dicarbiolide and. The system was dedicated for permeation of cadmium , cobalt Nickel and lead for use of this system for preconcentration and separation of cadmium, cobalt, nickel and lead. The work carried out in this thesis is presented in three parts, namely; introduction, experimental and results and discussion.The first chapter is the introduction which includes aim of work, basic concepts of liquid membranes; liquid emulsion membranes; different models of emulsion permeation, literature survey of extraction chemistry of cadmium, cobalt, nickel and lead. Chapter two includes the experimental part. In this part detailed outlines on the chemicals and different elements used were given. Different instruments as well as analytical techniques were outlines. The preparation of liquid emulsion membrane and the permeation techniques were presented in details. The third chapter deals with the results and discussion. This chapter is divided into four main parts, the four parts is concerned with cadmium/Co(III) dicarbolide/NTA, EDTA, DPTA and DCTA systems. In this part the permeation of Cd(II) aqueous solution by the membrane used was experimented based on liquid-liquid extraction studies of cadmium from different sodium chloride molarities (from 0.01 to 0.1 M) by 0.01 M Cobalt(III) dicarbolides. It was found that the extraction of with cadmium is higher following in the first system, the permeation of the toxic elements, Cd(II) from HCl/sodium chloride medium was carried out using liquid emulsion membrane containing Co(III)dicarbiolide in xylene as carrier, Spain 80/ Spain 85(1:3) as surfactant and NTA, EDTA, DPTA and DCTA as a stripping solutions.

  1. Differentiating aneurysm from infundibular dilatation by volume rendering MRA. Techniques for improving depiction of the posterior communicating and anterior choroidal arteries

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Takaaki; Ito, Takeo; Hasunuma, Masahiro; Sakamoto, Yasuo; Kohama, Ikuhide; Yonemori, Terutake; Izumo, Masaki [Hakodate Shintoshi Hospital, Hokkaido (Japan)

    2002-12-01

    With the spread of brain dock procedures, non-invasive magnetic resonance angiography (MRA) is being utilized to broadly screen for brain blood vessel diseases. However, diagnosis of cerebral aneurysm can be difficult by routine MRA. In particular, differentiating aneurysms and infundibular dilatations (IDS) of the posterior communicating artery (PCoA) and anterior choroidal artery (AChA) at their bifurcations with the internal carotid artery (ICA) is extremely difficult and additional studies are frequently necessary. In this situation, three-dimensional computed tomography angiography (3D-CTA) and cerebral angiography have been utilized, but both techniques are invasive. Furthermore, images from cerebral angiography are only two-dimensional, and 3D-CTA requires differentiation between aneurysm and ID by observing configurational changes at the apex of the protrusion and by following gradual changes to the threshold. We therefore undertook the following steps to improve both depiction of the PCoA and AChA and differential diagnosis between aneurysm and ID: reduced slice thickness and increased number of excitations; utilized volume rendering methods to construct images; lowered thresholds for the beginning of the PCoA and AChA arteries, which represent the regions of interest. In all 11 cases that we operated on, cerebral aneurysms were diagnosed correctly and the minimum neck diameter of the cerebral aneurysm was 1.2 mm. In addition, the number of AChAs and PCoAs present in target MRA and in operational views were evaluated. In one case with an AChA aneurysm, a PCoA was not detected by target MRA, because the ICA deviated posterolaterally and pushed the PCoA to the posterior clinoid process, and blood flow was poor in operational views. In another 2 cases with AChA aneurysms, only one AChA was described in target MRA, whereas two aneurysms were present. However, one of these had a diameter less than 1 mm. In conclusion, this method offers an extremely useful aid

  2. Differentiating aneurysm from infundibular dilatation by volume rendering MRA. Techniques for improving depiction of the posterior communicating and anterior choroidal arteries

    International Nuclear Information System (INIS)

    Kato, Takaaki; Ito, Takeo; Hasunuma, Masahiro; Sakamoto, Yasuo; Kohama, Ikuhide; Yonemori, Terutake; Izumo, Masaki

    2002-01-01

    With the spread of brain dock procedures, non-invasive magnetic resonance angiography (MRA) is being utilized to broadly screen for brain blood vessel diseases. However, diagnosis of cerebral aneurysm can be difficult by routine MRA. In particular, differentiating aneurysms and infundibular dilatations (IDS) of the posterior communicating artery (PCoA) and anterior choroidal artery (AChA) at their bifurcations with the internal carotid artery (ICA) is extremely difficult and additional studies are frequently necessary. In this situation, three-dimensional computed tomography angiography (3D-CTA) and cerebral angiography have been utilized, but both techniques are invasive. Furthermore, images from cerebral angiography are only two-dimensional, and 3D-CTA requires differentiation between aneurysm and ID by observing configurational changes at the apex of the protrusion and by following gradual changes to the threshold. We therefore undertook the following steps to improve both depiction of the PCoA and AChA and differential diagnosis between aneurysm and ID: reduced slice thickness and increased number of excitations; utilized volume rendering methods to construct images; lowered thresholds for the beginning of the PCoA and AChA arteries, which represent the regions of interest. In all 11 cases that we operated on, cerebral aneurysms were diagnosed correctly and the minimum neck diameter of the cerebral aneurysm was 1.2 mm. In addition, the number of AChAs and PCoAs present in target MRA and in operational views were evaluated. In one case with an AChA aneurysm, a PCoA was not detected by target MRA, because the ICA deviated posterolaterally and pushed the PCoA to the posterior clinoid process, and blood flow was poor in operational views. In another 2 cases with AChA aneurysms, only one AChA was described in target MRA, whereas two aneurysms were present. However, one of these had a diameter less than 1 mm. In conclusion, this method offers an extremely useful aid

  3. Short communication: Genetic characterization of digital cushion thickness.

    Science.gov (United States)

    Oikonomou, G; Banos, G; Machado, V; Caixeta, L; Bicalho, R C

    2014-01-01

    Dairy cow lameness is a serious animal welfare issue. It is also a significant cause of economic losses, reducing reproductive efficiency and milk production and increasing culling rates. The digital cushion is a complex structure composed mostly of adipose tissue located underneath the distal phalanx and has recently been phenotypically associated with incidence of claw horn disruption lesions (CHDL); namely, sole ulcers and white line disease. The objective of this study was to characterize digital cushion thickness genetically and to investigate its association with body condition score (BCS), locomotion score (LOCO), CHDL, and milk production. Data were collected from 1 large closely monitored commercial dairy farm located in upstate New York; 923 dairy cows were used. Before trimming, the following data were collected by a member of the research team: BCS, cow height measurement, and LOCO. Presence or not of CHDL (sole ulcer or white line disease, or both) was recorded at trimming. Immediately after the cows were hoof trimmed, they underwent digital sonographic B-mode examination for the measurement of digital cushion thickness. Factors such as parity number, stage of lactation, calving date, mature-equivalent 305-d milk yield (ME305MY), and pedigree information were obtained from the farm's dairy management software (DairyCOMP 305; Valley Agricultural Software, Tulare, CA). Univariate animal models were used to obtain variance component estimations for each studied trait (CHDL, BCS, digital cushion thickness average, LOCO, height, and ME305MY) and a 6-variate analysis was conducted to estimate the genetic, residual, and phenotypic correlations between the studied traits. The heritability estimate of DCTA was 0.33±0.09, whereas a statistically significant genetic correlation was estimated between DCTA and CHDL (-0.60±0.29). Of the other genetic correlations, significant estimates were derived for BCS with LOCO (-0.49±0.19) and ME305MY (-0.48±0.20). Digital

  4. Method for determining scan timing based on analysis of formation process of the time-density curve

    International Nuclear Information System (INIS)

    Yamaguchi, Isao; Ishida, Tomokazu; Kidoya, Eiji; Higashimura, Kyoji; Suzuki, Masayuki

    2005-01-01

    A strict determination of scan timing is needed for dynamic multi-phase scanning and 3D-CT angiography (3D-CTA) by multi-detector row CT (MDCT). In the present study, contrast media arrival time (T AR ) was measured in the abdominal aorta at the bifurcation of the celiac artery for confirmation of circulatory differences in patients. In addition, we analyzed the process of formation of the time-density curve (TDC) and examined factors that affect the time to peak aortic enhancement (T PA ). Mean T AR was 15.57±3.75 s. TDCs were plotted for each duration of injection. The rising portions of TDCs were superimposed on one another. TDCs with longer injection durations were piled up upon one another. Rise angle was approximately constant in response to each flow rate. Rise time (T R ) showed a good correlation with injection duration (T ID ). T R was 1.01 T ID (R 2 =0.994) in the phantom study and 0.94 T lD -0.60 (R 2 =0.988) in the clinical study. In conclusion, for the selection of optimal scan timing it is useful to determine T R at a given point and to determine the time from T AR . (author)

  5. Factors influencing consumers' attitudinal and behavioral responses to direct-to-consumer and over-the-counter drug advertising.

    Science.gov (United States)

    Lee, Mina; Whitehill King, Karen; Reid, Leonard N

    2015-04-01

    Using a model developed from the research literature, the authors compared consumers' attitudinal and behavioral responses to direct-to-consumer prescription drug advertising (DCTA) and over-the-counter nonprescription drug advertising (OTCA) of drugs. Adults 18 years of age and older who had taken any prescription drugs in the past 6 months completed online survey questionnaires. Variables measured included demographics (age, gender, race, education, and income), health-related characteristics (health status, prescription and over-the-counter drug use, health consciousness, and involvement with prescription or over-the-counter drugs), perceived amount of attention and exposure to DTCA and OTCA, attitudinal outcomes (skepticism toward DTCA/OTCA and attitude toward DTCA/OTCA), and behavioral outcomes triggered by DTCA and OTCA. The findings indicate that exposure to drug advertising is one of the most significant predictors of attitudinal and behavioral outcomes. Some audience factors such as health status, involvement with drugs, health consciousness, drug use, income, and age also were differentially associated with consumer responses to drug advertising.

  6. Moderator configuration options for a low-enriched uranium fueled Kilowatt-class Space Nuclear Reactor

    International Nuclear Information System (INIS)

    King, Jeffrey C.; Mencarini, Leonardo de Holanda; Guimaraes, Lamartine N. F.

    2015-01-01

    The Brazilian Air Force, through its Institute for Advanced Studies (Instituto de Estudos Avancados, IEAv/DCTA), and the Colorado School of Mines (CSM) are studying the feasibility of a space nuclear reactor with a power of 1-5 kW e and fueled with Low-Enriched Uranium (LEU). This type of nuclear reactor would be attractive to signatory countries of the Non-Proliferation Treaty (NPT) or commercial interests. A LEU-fueled space reactor would avoid the security concerns inherent with Highly Enriched Uranium (HEU) fuel. As an initial step, the HEU-fueled Kilowatt Reactor Using Stirling Technology (KRUSTY) designed by the Los Alamos National Laboratory serves as a basis for a similar reactor fueled with LEU fuel. Using the computational code MCNP6 to predict the reactor neutronics performance, the size of the resulting reactor fueled with 19.75 wt% enriched uranium-10 wt% molybdenum alloy fuel is adjusted to match the excess reactivity of KRUSTY. Then, zirconium hydride moderator is added to the core to reduce the size of the reactor. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between homogeneous and heterogeneous moderator systems, in terms of the core diameter required to meet a specific multiplication factor (k eff = 1.035). This comparison illustrates the impact of moderator configuration on the size and performance of a LEU-fueled kilowatt-class space nuclear reactor. (author)

  7. Separation of mercury(II), methylmercury and phenylmercury by micellar high-performance liquid chromatography on short columns

    International Nuclear Information System (INIS)

    Hutta, M.; Megova, S.; Halko, R.

    1998-01-01

    Three environmentally and agrochemically important mercury species: methylmercury, phenylmercury and mercury(II) are separated within 4 minutes as bromocomplexes by micellar liquid chromatography using very short reversed-phase (RP) C18 columns (up to 30 mm). The micellar mobile phase containing 0.05M cetyltrimethylammonium bromide (CTMA + Br - ), 1% (v/v) 2-propanol, 0.001M cyclohexylenediaminetetraacetic acid (DCTA) and sulfuric acid (pH 2) showed good selectivity in mixed reversed-phase and anion-exchange mode. The above mentioned separation order in which organomercurials are eluted far behind the void volume of the column, but before the mercury(II) peak is advantageous in all instances where mercury(II) is present in real samples in great excess. Environmental and agrochemical samples contain humic material which does not interfere in this particular system. The low cost photometric detection at 500 nm after post-column derivatization by CTMA + Br - micellized dithizone is almost free from interferences and enables detection limits at the 1-3 ng level (e.g., 0.1 ppm Hg) for 20 μl samples. (author)

  8. Use of 3D-computed tomography angiography for planning the surgical removal of pineal region meningiomas using Poppen's approach: a report of ten cases and a literature review

    Directory of Open Access Journals (Sweden)

    Li Ye

    2011-06-01

    Full Text Available Abstract Background There are several treatment approaches for pineal region meningiomas, such as Poppen's approach, Krause's approach and combinations of the two approaches. We present our experience with the use of 3D-computed tomography angiography for planning the surgical removal of pineal region meningiomas using a suboccipital transtentorial approach (Poppen's approach and evaluate the role of Poppen's approach. Methods During the period from January 2005 to June 2010, ten patients presented to us with pineal region meningioma. MRI was routinely used to define the tumor size, position, and its relevant complications while 3D-CTA was applied to define the blood supply of the tumor and the venous complex (VC shift before operations. Most of the meningiomas had developed at both sides of the tentorial plane and extended laterally with typical characteristics of a pineal region tumor. Results All tumors were completely removed surgically without any injury to the VC. Postoperative intracranial infection occurred in one case who recovered after antibiotics were given. Postoperative intraventricular hemorrhage and pneumocephalus were found in one case, but fully recovered after conservative treatment. In the nine cases of concurrent hydrocephalus, this was gradually relieved in eight patients and the single case that became aggravated was successfully treated with ventriculoperitoneal shunt. Moreover, the follow-up MRI examinations did not indicate any recurrence of the meningiomas. Conclusion We found that the use of Poppen's approach is strongly supported for the successful removal of pineal region meningiomas without serious complications.

  9. IDENTIFICAÇÃO POST-MORTEM BASEADA NA ANÁLISE DA ARACDA DENTAL- RELATO DE CASO

    Directory of Open Access Journals (Sweden)

    Naiara de Oliveira Pereira

    2017-03-01

    Full Text Available Resumo: Em 2003, ocorreu uma explosão na Base do Veículo Lançador de Satélites em Alcântara, no estado do Maranhão, que provocou 21 vítimas fatais, todas carbonizadas. O presente trabalho visou relatar uma simulação do processo de identificação de uma das vítimas, por meio da comparação dos dados do prontuário odontológico desenvolvido pelos cirurgiões dentistas do DCTA e de informações presentes no laudo de identificação elaborado pelos legistas do Maranhão. Como também, demonstrar a importância do preenchimento detalhado do odontograma e do cuidado com o feitio e arquivamento das imagens radiográficas e de todos os documentos odontológicos, que poderiam levar ao reconhecimento de um indivíduo. No confronto entre os registros AM e PM foram encontradas 06 similaridades, 12 discrepâncias e nenhuma incompatibilidade, permitindo associar positivamente a identidade da vítima ao corpo examinado. Esse processo teria sido facilitado se dados relacionados ao tipo de material restaurador e às faces envolvidas na restauração tivessem sido registrados com detalhes.

  10. The Scintillation Prediction Observations Research Task (SPORT): an International Science Mission Using a Cubesat

    Science.gov (United States)

    Spann, James; Swenson, Charles; Durao, Otavio; Loures, Luis; Heelis, Rod; Bishop, Rebecca; Le, Guan; Abdu, Mangalathayil; Krause, Linda; Fry, Craig; hide

    2017-01-01

    The Scintillation Prediction Observations Research Task (SPORT) is a 6U CubeSat mission to address the compelling but difficult problem of understanding the preconditions leading to equatorial plasma bubbles. The scientific literature describes the preconditions in both the plasma drifts and the density profiles related to bubble formations that occur several hours later in the evening. Most of the scientific discovery has resulted from observations at a single site, within a single longitude sector, from Jicamarca, Peru. SPORT will provide a systematic study of the state of the pre-bubble conditions at all longitudes sectors to enhance understanding between geography and magnetic geometry. SPORT is an international partnership between National Aeronautics and Space Administration (NASA), the Brazilian National Institute for Space Research (INPE), and the Technical Aeronautics Institute under the Brazilian Air Force Command Department (DCTA/ITA), and encouraged by U.S. Southern Command. This talk will present an overview of the SPORT mission, observation strategy, and science objectives to improve predictions of ionospheric disturbances that affect radio propagation of telecommunication signals. The science goals will be accomplished by a unique combination of satellite observations from a nearly circular middle inclination orbit and the extensive operation of ground based observations from South America near the magnetic equator.

  11. Automotive and aeronautical clusters in the São Paulo state’s Vale do Paraíba: a comparison of formation trajectories

    Directory of Open Access Journals (Sweden)

    Márcio da Silveira Luz

    2010-04-01

    Full Text Available This paper presents a comparison of the relevant characteristics of São Paulo State’s Vale do Paraíba automotive and aerospace clusters observed and analyzes the technological and productive chains strengthening. In order to accomplish it, the adopted methodological procedures are of qualitative nature, by means of documentary research. The results pointed out that the government established, in the mid-1945, the currently named Departamento de Ciência e Tecnologia Aeroespacial (DCTA, as a research and development (R&D center and, by 1979, Embraer, a state-owned aeronautical construction industry. It was also sought to generate conditions so that domestic companies could emerge around and replace the dependency on aerospace systems and subsystems international suppliers by developing indigenous technological capacities. The automotive cluster under study started in the São Paulo State’s Vale do Paraíba (PPV by means of the regionalization of multinational automotive construction firms migrated from ABC Paulista region looking for physical space for their growth, also relying on tax benefits. The survey results indicate that, in spite of fundamental differences with regard to their productive chains strenghtening processes, they showed similar adverse results.

  12. Accuracy and initial clinical experience with measurement software (advanced vessel analysis) in three-dimensional imaging

    International Nuclear Information System (INIS)

    Abe, Toshi; Hirohata, Masaru; Tanigawa, Hitoshi

    2002-01-01

    Recently, the clinical benefits of three dimensional (3D) imaging, such as 3D-CTA and 3D-DSA, in cerebro-vascular disease have been widely recognized. Software for quantitative analysis of vascular structure in 3D imaging (advanced vessel analysis: AVA) has been developed. We evaluated AVA with both phantom studies and a few clinical cases. In spiral and curvy aluminum tube phantom studies, the accuracy of diameter measurements was good in 3D images produced from data set generated by multi-detector row CT or rotational angiography. The measurement error was less than 0.03 mm on aluminum tube phantoms that were 3 mm and 5 mm in diameter. In the clinical studies, the differences of carotid artery diameter measurements between 2D-DSA and 3D-DSA was less than 0.3 mm in. The measurement of length, diameter and angle by AVA should provide useful information for planning surgical and endovascular treatments of cerebro-vascular disease. (author)

  13. Evaluation of the resolving power of different angles in MPR images of 16DAS-MDCT

    International Nuclear Information System (INIS)

    Kimura, Mikio; Usui, Junshi; Nozawa, Takeo

    2007-01-01

    In this study, we evaluated the resolving power of three-dimensional (3D) multiplanar reformation (MPR) images with various angles by using 16 data acquisition system multi detector row computed tomography (16DAS-MDCT). We reconstructed the MPR images using data with a 0.75 mm slice thickness of the axial image in this examination. To evaluate resolving power, we used an original new phantom (RC phantom) that can be positioned at any slice angle in MPR images. We measured the modulation transfer function (MTF) by using the methods of measuring pre-sampling MTF, and used Fourier transform of image data of the square wave chart. The scan condition and image reconstruction condition that were adopted in this study correspond to the condition that we use for three-dimensional computed tomographic angiography(3D-CTA) examination of the head in our hospital. The MTF of MPR images showed minimum values at slice angles in parallel with the axial slice, and showed maximum values at the sagittal slice and coronal slice angles that are parallel to the Z-axis. With an oblique MPR image, MTF did not change with angle changes in the oblique sagittal slice plane, but in the oblique coronal slice plane, MTF increased as the tilt angle increased from the axial plane to the Z plane. As a result, we could evaluate the resolving power of a head 3D image by measuring the MTF of the axial image and sagittal image or the coronal image. (author)

  14. [Evaluation of the resolving power of different angles in MPR images of 16DAS-MDCT].

    Science.gov (United States)

    Kimura, Mikio; Usui, Junshi; Nozawa, Takeo

    2007-03-20

    In this study, we evaluated the resolving power of three-dimensional (3D) multiplanar reformation (MPR) images with various angles by using 16 data acquisition system multi detector row computed tomography (16DAS-MDCT) . We reconstructed the MPR images using data with a 0.75 mm slice thickness of the axial image in this examination. To evaluate resolving power, we used an original new phantom (RC phantom) that can be positioned at any slice angle in MPR images. We measured the modulation transfer function (MTF) by using the methods of measuring pre-sampling MTF, and used Fourier transform of image data of the square wave chart. The scan condition and image reconstruction condition that were adopted in this study correspond to the condition that we use for three-dimensional computed tomographic angiography (3D-CTA) examination of the head in our hospital. The MTF of MPR images showed minimum values at slice angles in parallel with the axial slice, and showed maximum values at the sagittal slice and coronal slice angles that are parallel to the Z-axis. With an oblique MPR image, MTF did not change with angle changes in the oblique sagittal slice plane, but in the oblique coronal slice plane, MTF increased as the tilt angle increased from the axial plane to the Z plane. As a result, we could evaluate the resolving power of a head 3D image by measuring the MTF of the axial image and sagittal image or the coronal image.

  15. Characterization of a radiation detector for aircraft measurements

    International Nuclear Information System (INIS)

    Holanda M, L. de; Federico, C. A.; Caldas, L. V. E.

    2014-08-01

    Air crews, as pilots and flight attendants, are subjected to cosmic ray doses which can be higher than the average doses on workers from the nuclear industry. The diversity of particles of high energies present in the radiation field on board of air crafts turns the determination of the incident dose difficult, and requires special care regarding dosimetric systems to be used in this kind of radiation field. The Brazilian Air Force, through its Institute for Advanced Studies (Instituto de Estudos Avancados, IEAv/DCTA) in conjunction with the Institute of Energetic and Nuclear Research (Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP) are working on this subject since 2008. A prototype of a radiation detector for aircraft measurements was previously built and tested in flight and laboratory conditions. The detector is able of measuring a quantity known as absorbed dose (using passive dosimeters), which will subsequently be correlated to the ambient dose equivalent and the effective dose received by air crews. In this context, a theoretical approach through Monte Carlo simulations with the computational codes MCNP5 and MCNPX was used to model and characterize the detector response at such experimental conditions. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between the absorbed doses measured and simulated, and its relationship with the ambient dose equivalent and the effective dose for this detector. (author)

  16. Moderator configuration options for a low-enriched uranium fueled Kilowatt-class Space Nuclear Reactor

    Energy Technology Data Exchange (ETDEWEB)

    King, Jeffrey C., E-mail: kingjc@mines.edu [Nuclear Science and Engineering Program, Colorado School of Mines (CSM), Golden, CO (United States); Mencarini, Leonardo de Holanda; Guimaraes, Lamartine N. F., E-mail: guimaraes@ieav.cta.br, E-mail: mencarini@ieav.cta.br [Instituto de Estudos Avancados (IEAV), Sao Jose dos Campos, SP (Brazil). Divisao de Energia Nuclear

    2015-07-01

    The Brazilian Air Force, through its Institute for Advanced Studies (Instituto de Estudos Avancados, IEAv/DCTA), and the Colorado School of Mines (CSM) are studying the feasibility of a space nuclear reactor with a power of 1-5 kW{sub e} and fueled with Low-Enriched Uranium (LEU). This type of nuclear reactor would be attractive to signatory countries of the Non-Proliferation Treaty (NPT) or commercial interests. A LEU-fueled space reactor would avoid the security concerns inherent with Highly Enriched Uranium (HEU) fuel. As an initial step, the HEU-fueled Kilowatt Reactor Using Stirling Technology (KRUSTY) designed by the Los Alamos National Laboratory serves as a basis for a similar reactor fueled with LEU fuel. Using the computational code MCNP6 to predict the reactor neutronics performance, the size of the resulting reactor fueled with 19.75 wt% enriched uranium-10 wt% molybdenum alloy fuel is adjusted to match the excess reactivity of KRUSTY. Then, zirconium hydride moderator is added to the core to reduce the size of the reactor. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between homogeneous and heterogeneous moderator systems, in terms of the core diameter required to meet a specific multiplication factor (k{sub eff} = 1.035). This comparison illustrates the impact of moderator configuration on the size and performance of a LEU-fueled kilowatt-class space nuclear reactor. (author)

  17. Three-dimensional bone-free computed tomographic angiography of aneurysms near the skull base using a new bone-removal application

    International Nuclear Information System (INIS)

    Tomura, Noriaki; Otani, Takahiro; Sakuma, Ikuo; Takahashi, Satoshi; Nishii, Toshiaki; Watarai, Jiro

    2009-01-01

    Bone elimination is needed for computed tomography angiography (CTA) because bone structures obscure aneurysms located at the skull base. The purpose of our study was to evaluate the efficacy of three-dimensional (3D)-CTA using an application for bone elimination. A total of 27 patients with 32 angiographically confirmed aneurysms near the skull base were investigated. The 3D maximum intensity projection (MIP) images were initially obtained using the application. Further postprocessing was performed to obtain the MIP and volume-rendered (VR) images. The quality of the initial MIP images by the application was analyzed. Visualization of aneurysms after further processing was also reviewed. The initial MIP images by the application showed almost bone-free images in 23 of the 27 patients. In 8 patients, the image of the internal carotid artery (ICA) was segmentally removed in the initial MIP images by the application. Further postprocessing was able to recover all loss of the ICA image in these eight patients. For visualizing aneurysms and their necks, VR images with the application were significantly superior to VR images without the application. The application for bone elimination allows fast, selective elimination of bony structures and can improve the interpretation of aneurysms near the skull base. (author)

  18. Characterization of a radiation detector for aircraft measurements

    Energy Technology Data Exchange (ETDEWEB)

    Holanda M, L. de; Federico, C. A.; Caldas, L. V. E., E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares, Av. Lineu Prestes 2242, Cidade Universitaria, CEP 05508-000, Sao Paulo (Brazil)

    2014-08-15

    Air crews, as pilots and flight attendants, are subjected to cosmic ray doses which can be higher than the average doses on workers from the nuclear industry. The diversity of particles of high energies present in the radiation field on board of air crafts turns the determination of the incident dose difficult, and requires special care regarding dosimetric systems to be used in this kind of radiation field. The Brazilian Air Force, through its Institute for Advanced Studies (Instituto de Estudos Avancados, IEAv/DCTA) in conjunction with the Institute of Energetic and Nuclear Research (Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP) are working on this subject since 2008. A prototype of a radiation detector for aircraft measurements was previously built and tested in flight and laboratory conditions. The detector is able of measuring a quantity known as absorbed dose (using passive dosimeters), which will subsequently be correlated to the ambient dose equivalent and the effective dose received by air crews. In this context, a theoretical approach through Monte Carlo simulations with the computational codes MCNP5 and MCNPX was used to model and characterize the detector response at such experimental conditions. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between the absorbed doses measured and simulated, and its relationship with the ambient dose equivalent and the effective dose for this detector. (author)

  19. CT during selective arteriography: anatomical assessment of unruptured intracranial aneurysms before endovascular treatment

    International Nuclear Information System (INIS)

    Nomura, M.; Kida, S.; Uchiyama, N.; Yamashima, T.; Yamashita, J.; Sanada, J.; Yoshikawa, J.; Matsui, O.

    2001-01-01

    Our aim was to investigate the usefulness of helical CT during selective angiography (CT arteriography) in pretreatment assessment of unruptured intracranial aneurysms. We studied 47 unruptured aneurysms in 34 prospectively recruited patients for whom endovascular embolisation was initially considered. As pretreatment assessment, we performed rotational digital subtraction angiography (DSA) followed by CT arteriography. The findings on axial source images (axial images) and reconstructed three-dimensional CT angiography (3D-CTA) of CT arteriography were compared to those of rotational DSA, with particular attention to the neck of the aneurysm and arterial branches adjacent to it. Information provided by CT arteriography was more useful than that of rotational DSA as regards the neck in 25 (53 %) of 47 cases and as regards branches in 18 (49 %) of 37 aneurysms. On axial images, small arteries such as the anterior choroidal artery were seen in some cases. CT arteriography can provide valuable additional information about unruptured aneurysms, which cannot be obtained by rotational DSA alone. This technique is useful for obtaining anatomical information about aneurysm anatomy and for deciding the therapeutic strategy. (orig.)

  20. Clinical features of 10 patients with spontaneous cervical internal carotid artery dissection

    International Nuclear Information System (INIS)

    Nagoya, Harumitsu; Takeda, Hidetaka; Dembo, Tomohisa; Kato, Yuzi; Deguchi, Ichiro; Fukuoka, Takuya; Maruyama, Hazime; Horiuchi, Yohsuke; Tanahashi, Norio

    2011-01-01

    We clinically investigated 10 patients with spontaneous cervical internal carotid artery dissections (age range 36-70, mean 52±12 years; 8 male and 2 female) who were admitted to our university hospital between August 2002 and 2009. Cervical internal carotid artery dissection was diagnosed using findings from MRI, MR angiography (MRA), 3D-CTA, cerebral angiography, and carotid artery ultrasonography according to the diagnostic criteria of brain artery dissociation defined by the brain artery dissociation working group of the Strategies Against Stroke Study for Young Adults in Japan. The initial symptoms were stroke in eight patients, only neck pain in another, and no symptoms in the last. Four patients (40%) had neck pain or headache at onset. Five of the 10 patients had radiological improvements within three months after onset. The outcomes at three months were relatively good, with seven and three patients scoring 1 and 2, respectively, on the modified Rankin Scale. Disease did not recur in any patients during an average of 17.2 months of follow up. Spontaneous cervical internal carotid artery dissection is not rare in Japan. This condition should be considered when patients present with internal carotid artery occlusion or stenosis. (author)

  1. The Scintillation Prediction Observations Research Task (SPORT): A Multinational Science Mission using a CubeSat

    Science.gov (United States)

    Spann, J. F.; Habash Krause, L.; Swenson, C.; Heelis, R. A.; Bishop, R. L.; Le, G.; Abdu, M. A.; Durão, O.; Loures, L.; De Nardin, C. M.; Shibuya, L.; Casas, J.; Nash-STevenson, S.; Muralikrishana, P.; Costa, J. E. R.; Wrasse, C. M.; Fry, C. D.

    2017-12-01

    The Scintillation Prediction Observations Research Task (SPORT) is a 6U CubeSat pathfinder mission to address the very compelling but difficult problem of understanding the preconditions leading to equatorial plasma bubbles. The scientific literature describes the preconditions in both the plasma drifts and the density profiles related to bubble formations that occur several hours later in the evening. Most of the scientific discovery has resulted from observations at the Jicamarca Radio Observatory from Peru, a single site, within a single longitude sector. SPORT will provide a systematic study of the state of the pre-bubble conditions at all longitudes sectors to allow us to understand the differences between geography and magnetic geometry. This talk will present an overview of the mission and the anticipated data products. Products include global maps of scintillation occurrence as a function of local time, and magnetic conjugacy occurrence observations. SPORT is a multinational partnership between NASA, the Brazilian National Institute for Space Research (INPE), and the Technical Aeronautics Institute under the Brazilian Air Force Command Department (DCTA/ITA). It has been encouraged by U.S. Southern Command (SOUTHCOM) to foster increased cooperation and ties between academics, civilian space programs and the militaries. NASA Marshall Space Flight Center is coordinating this investigation by overseeing the launch to orbit and the flight instruments, which are being built by the Aerospace Corporation, University of Texas Dallas, Utah State University, and NASA Goddard Space Flight Center. The Brazilian partners are contributing the spacecraft, observatory integration and test, ground observation networks, and mission operations and data management. The science data will be distributed from and archived at the INPE/EMBRACE regional space-weather forecasting center in Brazil, and mirrored at the NASA GSFC Space Physics Data Facility (SPDF).