WorldWideScience

Sample records for time-density curve angiographic

  1. Endovascular image-guided treatment of in-vivo model aneurysms with asymmetric vascular stents (AVS): evaluation with time-density curve angiographic analysis and histology.

    Science.gov (United States)

    Dohatcu, A; Ionita, C N; Paciorek, A; Bednarek, D R; Hoffmann, K R; Rudin, S

    2008-01-01

    In this study, we compare the results obtained from Time-Density Curve (TDC) analysis of angiographic imaging sequences with histological evaluation for a rabbit aneurysm model treated with standard stents and new asymmetric vascular stents (AVS) placed by image-guided endovascular deployment. AVSs are stents having a low-porosity patch region designed to cover the aneurysm neck and occlude blood flow inside. To evaluate the AVSs, rabbits with elastase-induced aneurysm models (n=20) were divided into three groups: the first (n=10) was treated with an AVS, the second (n=5) with a non-patch standard coronary stent, and third was untreated as a control (n=5). We used TDC analysis to measure how much contrast media entered the aneurysm before and after treatment. TDCs track contrast-media-density changes as a function of time over the region of interest in x-ray DSA cine-sequences. After 28 days, the animals were sacrificed and the explanted specimens were histologically evaluated. The first group showed an average reduction of contrast flow into the aneurysm of 95% after treatment with an AVS with fully developed thrombus at 28 days follow-up. The rabbits treated with standard stents showed an increase in TDC residency time after treatment and partial-thrombogenesis. The untreated control aneurysms displayed no reduction in flow and were still patent at follow-up. The quantitative TDC analysis findings were confirmed by histological evaluation suggesting that the new AVS has great potential as a definitive treatment for cerebro-vascular aneurysms and that angiographic TDC analysis can provide in-vivo verification.

  2. Evaluation of cerebral intravascular blood flow by time density curve study of intravenous digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, Toru; Kogure, Kyuya (Tohoku Univ., Sendai (Japan). School of Medicine); Sekine, Teiko; Satoh, Kei; Endoh, Minoru; Tsuburaya, Kenji; Hoshi, Akihiko

    1992-01-01

    Time density curve (TDC) can be reconstructed from the data of intravenous digital subtraction angiography (IVDSA). We evaluated peak time (PT) and modal transit time (MOTT) of the TDC as the probable indicator of cerebral intravascular blood flow. Cerebral IVDSA and single photon emission CT (SPECT) were performed on 12 patients with ischemic cerebrovascular disease, which consisted of 3 internal carotid artery (ICA) occlusions, one middle cerebral artery (MCA) occlusion, one anterior cerebral artery (ACA) branch occlusion and 7 lacunar infarctions. We classified former 4 patients as occlusion group and latter 8 as reference group. In 3 patients (2 ICA and one MCA occlusions), SPECT study revealed definite hypoaccumulation in the MCA territory of occlusive side. Two regions of interest (ROI) were placed on the territories of right and left middle cerebral arteries in the frontal view of cerebral IVDSA. Digital data processor fitted {gamma} curve to the TDC of each ROI, and calculated PT and MOTT. The absolute lateralities of PT and MOTT of MCA territory was significantly (p<0.05) larger in occlusion group than reference group. Patients with hypoaccumulation in SPECT had significantly (p<0.02) larger laterality of MOTT than patients with isoaccumulation. One ICA occluded patient without hypoaccumulation in corresponding MCA territory had relatively small laterality of MOTT similar to the patients of ACA branch occlusion and lacunar infarction. These results suggest that PT and MOTT are possible to detect the laterality of the intravascular blood flow in MCA territories caused by major artery occlusion. Cerebral TDC study of IVDSA may be useful in some clinical therapeutic situations such as hemodilution or intra-arterial thrombolysis, and worth further clinical evaluation. (author).

  3. 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)

  4. Usefulness of measurement of circulation time using MgSO4 : correlation with time-density curve using electron beam computed tomography

    International Nuclear Information System (INIS)

    Kim, Byung Ki; Lee, Hui Joong; Lee, Jong Min; Kim, Yong Joo; Kang, Duck Sik

    1999-01-01

    To determine the usefulness of MgSO 4 for measuring the systemic circulation time. Systemic circulation time, defined as elapsed time from the injection of MgSO 4 solution to the point of pharyngeal burning sensation, was measured in 63 volunteers. MgSO 4 was injected into a superficial vein of an upper extremity. Using dynamic electron beam computed tomography at the level of the abdominal aorta and celiac axis, a time-intensity curve was plotted, and for these two locations, maximal enhancement time was compared. For 60 of the 63 subjects, both systemic circulation time and maximal enhancement time were determined. Average systemic circulation time was 17.4 (SD:3.6) secs. and average maximal enhancement times at the level of the abdominal aorta and celiac axis were 17.5 (SD:3.0) secs. and 18.5 (SD:3.2) secs., respectively. Correlation coefficients between systemic circulation time and maximal enhancement time for the abdominal aorta and celiac axis were 0.73 (p 4 injection and maximal enhancement time for the abdominal aorta showed significant correlation. Thus, to determine the appropriate scanning time in contrast-enhanced radiological studies, MgSO 4 can be used instead of a test bolus study

  5. An angiographic technique for coronary fractional flow reserve measurement: in vivo validation.

    Science.gov (United States)

    Takarada, Shigeho; Zhang, Zhang; Molloi, Sabee

    2013-03-01

    Fractional flow reserve (FFR) is an important prognostic determinant in a clinical setting. However, its measurement currently requires the use of invasive pressure wire, while an angiographic technique based on first-pass distribution analysis and scaling laws can be used to measure FFR using only image data. Eight anesthetized swine were instrumented with flow probe on the proximal segment of the left anterior descending (LAD) coronary arteries. Volumetric blood flow from the flow probe (Qp), coronary pressure (Pa) and right atrium pressure (Pv) were continuously recorded. Flow probe-based FFR (FFRq) was measured from the ratio of flow with and without stenosis. To determine the angiography-based FFR (FFRa), the ratio of blood flow in the presence of a stenosis (QS) to theoretically normal blood flow (QN) was calculated. A region of interest in the LAD arterial bed was drawn to generate time-density curves using angiographic images. QS was measured using a time-density curve and the assumption that blood was momentarily replaced with contrast agent during the injection. QN was estimated from the total coronary arterial volume using scaling laws. Pressure-wire measurements of FFR (FFRp), which was calculated from the ratio of distal coronary pressure (Pd) divided by proximal pressure (Pa), were continuously obtained during the study. A total of 54 measurements of FFRa, FFRp, and FFRq were taken. FFRa showed a good correlation with FFRq (FFRa = 0.97 FFRq +0.06, r(2) = 0.80, p < 0.001), although FFRp overestimated the FFRq (FFRp = 0.657 FFRq + 0.313, r(2) = 0.710, p < 0.0001). Additionally, the Bland-Altman analysis showed a close agreement between FFRa and FFRq. This angiographic technique to measure FFR can potentially be used to evaluate both anatomical and physiological assessments of a coronary stenosis during routine diagnostic cardiac catheterization that requires no pressure wires.

  6. Evaluation of angiographic delayed vasospasm due to ruptured aneurysm in comparison with cerebral circulation time measured by IA-DSA

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Yoshikazu; Shima, Takeshi; Nishida, Masahiro; Yamane, Kanji; Okita, Shinji; Hatayama, Takashi; Yoshida, Akira; Naoe, Yasutaka; Shiga, Naoko (Chugoku Rosai Hospital, Hiroshima (Japan))

    1994-05-01

    Delayed vasospasm due to ruptured aneurysm has been basically evaluated by angiographic changes in contrast to clinical features such as delayed ischemic neurological deficits (DIND). However, the discrepancies between angiographic and clinical findings have been pointed out. In this study, angiographic changes and cerebral circulation time in ruptured aneurysms were simultaneously investigated with IA-DSA. Thirty-two patients, who had ruptured aneurysms at the anterior circle of Willis and neck clippings at the acute stage, were investigated. Carotid angiogram was performed with IA-DSA on the 7-13th day after the attack. Angiographic changes were evaluated by Fischer's classification and circulation time was calculated in the following way. A time-density curve was obtained at the two ROI's: the C3-C4 portion and the rolandic vein. Circulation time was defined by the difference between the time showing peak optical density at the carotid and the venous portion. The control value of this circulation time obtained from 20 cases with non-rupture aneurysm and epilepsy was 3.4 sec (53 year old) on the average. X-ray CT scan examination was performed at the same time and clinical features were observed every day. Angiographically, 3 cases were free from vasospasm, 18 cases were found to present slight to moderate vasospasm, and 11 cases showed severe vasospasm. Circulation time in patients with no spasm was 3.6 seconds, in patients with slight to moderate vasospasm it was 4.3 seconds and in patients with severe vasospasm it was 6.8 seconds. Ten patients showing cerebral infarction on CT scans demonstrated significantly long circulation time, 7.0 seconds on the average. And all patients having severe vasospasm with circulation time more than 6 seconds presented DIND such as hemiparesis. (author).

  7. Radiation dose during angiographic procedures

    International Nuclear Information System (INIS)

    Lavoie, Ch.; Rasuli, P.

    2001-01-01

    The use of angiographic procedures is becoming more prevalent as new techniques and equipment are developed. There have been concerns in the scientific community about the level of radiation doses received by patients, and indirectly by staff, during some of these radiological procedures. The purpose of this study was to assess the level of radiation dose from angiographic procedures to patient at the Ottawa Hospital, General Campus. Radiation dose measurements, using Thermo-Luminescent Dosimeters (TLDs), were performed on more than 100 patients on various procedures. The results show that while the patient dose from the great majority of angiographic procedures is less than 2 Gy, a significant number of procedures, especially interventional procedures may have doses greater than 2 Gy and may lead to deterministic effects. (author)

  8. Coronary angiographic characteristics that influence fractional flow reserve.

    Science.gov (United States)

    Natsumeda, Makoto; Nakazawa, Gaku; Murakami, Tsutomu; Torii, Sho; Ijichi, Takeshi; Ohno, Yohei; Masuda, Naoki; Shinozaki, Norihiko; Ogata, Nobuhiko; Yoshimachi, Fuminobu; Ikari, Yuji

    2015-01-01

    Percutaneous coronary intervention (PCI) guided with fractional flow reserve (FFR) has been shown to improve clinical outcome. Although coronary angiography is the standard method for PCI guidance, the visual severity of stenosis is not always correlated with functional severity, suggesting that there are additional angiographic factors that affect functional ischemia. To evaluate angiographic predictors of positive FFR in stenotic lesions, angiographic characteristics of 260 consecutive patients (362 lesions) who underwent FFR testing from April 2009 to September 2012 were analyzed. A scoring system (STABLED score) using these predictors was developed and compared with quantitative coronary angiography (QCA). %Diameter stenosis >50% (OR, 8.43; P20 mm (OR, 5.40; P=0.0002), and distance from ostium <20 mm (OR, 1.94; P=0.028) were determined as independent predictors of positive FFR. Area under the ROC curve for probability of positive FFR using the STABLED score (Stenosis 2 points, TAndem lesion 1 point, Bifurcation 1 point, LEsion length 1 point, Distance from ostium 1 point) was 0.85, higher than that for QCA stenosis alone (0.76). STABLED score ≥3 had 72.3% sensitivity and 83.6% specificity for predicting positive FFR, and PPV was 76.7%. Specific angiographic features are applicable for predicting functional ischemia. STABLED score correlates well with FFR.

  9. Angiographic findings of hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Han, Man Chung; Cho, Byung Jae; Huh, Seung Jae; Bae, Sang Hoon; Kim, Ung Jin; Kim, Chung Yong; Kim, Noe Kyeong [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1985-12-15

    From March 1977 to July 1979, 69 cases of angiograms of hepatocellular carcinoma were observed in Seoul National University Hospital. The findings of selective celiac and/or hepatic arteriography in total 69 cases of confirmed hepatocellular carcinoma, with clinical and laboratory findings, were analyzed. The summarized results are as follows; 1. Among 69 cases od hepatoma, 62 were male and 7 were female with sex ratio of 8.9 : 1. Peak incidence is 5th to 7th decades (72.5%). Epigastric pain, indigestion, and palpable mass in right upper quadrant were common symptoms and sign. Laboratory findings showed elevated serum alkaline phosphatase more than 5 Bodansky unit in 75.4%. Alpha-feto protein was positive in 65.2% of all the patients. 2 All 69 cases were classified into 31 cases of massive type, 22 cases of diffuse type, and 16 cases of nodular type, in accordance with angiographic gross anatomy. The frequency of angiographic findings were hypervascularities and tumor vessels (100%), tumor stainings (98.5%), arteriovenous shunt (71.0%), displacement of intrahepatic arteries (66.7%), vascular lakes and channel (59.4%). Encasement of hepatic artery and portal vein regurgitation was respectively 4 cases. Tumor mass in portal vein were 6 cases and tumor mass in hepatic vein was 1 case. 3. Intraarterial infusion of 5-FU was performed in 15 hepatoma patients, and the results were that angiographic improvement was demonstrated in 3 cases, no improvement in 8 cases, and incomplete infusion in 4 cases. 4. The selective celiac and/or hepatic angiograms are excellent diagnostic tools as well as therapeutic management for intraarterial infusion of anticancerous drugs.

  10. Angiographic findings of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Han, Man Chung; Cho, Byung Jae; Huh, Seung Jae; Bae, Sang Hoon; Kim, Ung Jin; Kim, Chung Yong; Kim, Noe Kyeong

    1985-01-01

    From March 1977 to July 1979, 69 cases of angiograms of hepatocellular carcinoma were observed in Seoul National University Hospital. The findings of selective celiac and/or hepatic arteriography in total 69 cases of confirmed hepatocellular carcinoma, with clinical and laboratory findings, were analyzed. The summarized results are as follows; 1. Among 69 cases od hepatoma, 62 were male and 7 were female with sex ratio of 8.9 : 1. Peak incidence is 5th to 7th decades (72.5%). Epigastric pain, indigestion, and palpable mass in right upper quadrant were common symptoms and sign. Laboratory findings showed elevated serum alkaline phosphatase more than 5 Bodansky unit in 75.4%. Alpha-feto protein was positive in 65.2% of all the patients. 2 All 69 cases were classified into 31 cases of massive type, 22 cases of diffuse type, and 16 cases of nodular type, in accordance with angiographic gross anatomy. The frequency of angiographic findings were hypervascularities and tumor vessels (100%), tumor stainings (98.5%), arteriovenous shunt (71.0%), displacement of intrahepatic arteries (66.7%), vascular lakes and channel (59.4%). Encasement of hepatic artery and portal vein regurgitation was respectively 4 cases. Tumor mass in portal vein were 6 cases and tumor mass in hepatic vein was 1 case. 3. Intraarterial infusion of 5-FU was performed in 15 hepatoma patients, and the results were that angiographic improvement was demonstrated in 3 cases, no improvement in 8 cases, and incomplete infusion in 4 cases. 4. The selective celiac and/or hepatic angiograms are excellent diagnostic tools as well as therapeutic management for intraarterial infusion of anticancerous drugs.

  11. Angiographic appearances of rare renal tumours

    International Nuclear Information System (INIS)

    Schmidt, M.; Taenzer, V.

    1980-01-01

    Oncocytomas, called oxyphil proximal tubular adenomas in the Anglo Saxon literature, and benign hypernephromas are non-malignant, usually symptomless, rare tumours belonging to the renal adenomas. Oncocytomas have angiographic appearances sufficiently uniform to permit a tentative diagnosis. Histologically benign hypernephromas do not possess characteristic angiographic appearances and, in the presence of tumour in the renal vein or necrotic avascular areas, must be regarded as potentially malignant. (orig.) [de

  12. Multislice computed tomography: angiographic emulation versus standard assessment for detection of coronary stenoses

    Energy Technology Data Exchange (ETDEWEB)

    Schnapauff, Dirk; Hamm, Bernd; Dewey, Marc [Humboldt-Universitaet zu Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin, Chariteplatz 1, P.O. Box 10098, Berlin (Germany); Duebel, Hans-Peter; Baumann, Gert [Charite - Universitaetsmedizin Berlin, Department of Cardiology, Berlin (Germany); Scholze, Juergen [Charite - Universitaetsmedizin Berlin, Charite Outpatient Centre, Berlin (Germany)

    2007-07-15

    The present study investigated angiographic emulation of multislice computed tomography (MSCT) (catheter-like visualization) as an alternative approach of analyzing and visualizing findings in comparison with standard assessment. Thirty patients (120 coronary arteries) were randomly selected from 90 prospectively investigated patients with suspected coronary artery disease who underwent MSCT (16-slice scanner, 0.5 mm collimation, 400 ms rotation time) prior to conventional coronary angiography for comparison of both approaches. Sensitivity and specificity of angiographic emulation [81% (26/32) and 93% (82/88)] were not significantly different from those of standard assessment [88% (28/32) and 99% (87/88)], while the per-case analysis time was significantly shorter for angiographic emulation than for standard assessment (3.4 {+-} 1.5 vs 7.0 {+-} 2.5 min, P < 0.001). Both interventional and referring cardiologists preferred angiographic emulation over standard curved multiplanar reformations of MSCT coronary angiography for illustration, mainly because of improved overall lucidity and depiction of sidebranches (P < 0.001). In conclusion, angiographic emulation of MSCT reduces analysis time, yields a diagnostic accuracy comparable to that of standard assessment, and is preferred by cardiologists for visualization of results. (orig.)

  13. Radiologist and angiographic procedures. Absorbed radiation dose

    International Nuclear Information System (INIS)

    Tryhus, M.; Mettler, F.A. Jr.; Kelsey, C.

    1987-01-01

    The radiation dose absorbed by the angiographer during angiographic procedures is of vital importance to the radiologist. Nevertheless, most articles on the subject are incomplete, and few measure gonadal dose. In this study, three TLDs were used for each of the following sites: radiologist's eyes, thyroid, gonads with and without shielding apron, and hands. The average dose during carotid angiograms was 2.6, 4.1, 0.4, 4.7, and 7.1 mrads to the eyes, thyroid, gonads with and without .5 mm of lead shielding, and hands, respectively. Average dose during abdominal and peripheral vascular angiographic procedures was 5.2, 7.5, 1.2, 8.5, and 39.9 mrads to the eyes, thyroid, gonads with and without shielding, and hands, respectively. A literature review demonstrates a significant reduction in radiation dose to the angiographer after the advent of automated injectors. Our measured doses for carotid angiography are compatible with contemporary reported values. There was poor correlation with fluoroscopy time and measured dose to the angiographer

  14. A simple digital subtraction angiographic instrument

    International Nuclear Information System (INIS)

    Ando, Hiroshi; Kobayashi, Tsuyoshi; Imai, Yutaka; Yanagishita, Akira

    1983-01-01

    A digital subtraction angiographic instrument was manufactured using a conventional x-ray TV for gastrointestinal series and a computer for processing of nuclear medical data. The results of visualization of the aorta and its primary branches were reviewed with demonstrable cases. (Chiba, N.)

  15. Exposure doses to angiographers during interventional angiography

    International Nuclear Information System (INIS)

    Fukutomi, Yukimi; Yasuhara, Yoshifumi; Sugata, Shigenori; Fujii, Takashi; Kawakami, Toshiaki; Ikezoe, Junpei

    1997-01-01

    We report the exposure doses to angiographers during interventional angiography and the protective efficacy of protective aprons against X-rays in this study. The first (main) angiographer was exposed to the maximum dose of 1 μSv/min at the left chest area and lower abdominal area inside the protective apron. The second (assistant) angiographer was exposed to the maximum dose of 2 μSv/min at the left chest area and 1 μSv/min at the lower abdominal area. X-ray transmission ratio of the protective apron was 4.9 percent or less for UL25L, O percent for 0.35 mmPb and 4.3 percent or less for 0.5 mmPb. These results were lower than the dose equivalent limit based on the laws and ordinances. The protection capacities of these protective aprons proved to be sufficient. The exposure dose at the left extremity area outside the protective apron, however, was 24 times higher than at the left chest area inside. The data showed that it was not protected from scattered X-rays outside the protective apron. It is imperative to consider secondary protective material for the area outside the protective apron. Considering the risk of radiation, we need to better control exposure to angiographers. (author)

  16. Essentials of diagnostic and interventional angiographic technique

    International Nuclear Information System (INIS)

    Gerlock, A.J.; Mirfakhraee, M.

    1985-01-01

    This volume presents coverage of basic angiographic techniques and shows how to get to the point of taking the angiogram, and tells how to avoid pitfalls. Particularly valuable is the information on how to get out of trouble if an error is made while manipulating the catheter

  17. Angiographic diagnosis of the carotid artery pseudoaneurysm

    International Nuclear Information System (INIS)

    Qi Yueyong; Zou Liguang; Dai Shuhua; Tan Yinghui; Li Zhongyu; Zhou Zheng

    2004-01-01

    Objective: To create a further understanding of the angiographic features of the carotid artery pseudoaneurysm (CAPA) and to explore the clinical diagnostic value of angiography. Methods: Sixteen cases of CAPA with clinical and angiographic data were analyzed retrospectively. The angiographic appearances in all of the patients were observed dynamically and precisely with a double blind method by two experienced radiologists together and formed a consensus interpretation. Results: Angiography provided a definite diagnosis for all cases. The parent arteries included the common carotid artery (1 case), common carotid artery bifurcation (9 cases), internal carotid artery (5 cases) and external carotid artery (1 case). The angiographic features of the CAPA were: All cases showed the contrast media retension in the aneurysms; turbulent flow within aneurysm in 9 cases; the 'jetting sign' at the leak of the parent artery in 7 cases; increase angulation of the bifurcation of internal and external carotid arteries in 12 cases. Conclusions: Angiography is the most valuable examination method in diagnosis of CAPA, and it can not only provide definite diagnosis, but also play an important role in selection of therapeutic plan. (authors)

  18. Relationship between Angiographic Results and Morphology in Sidewall Intracranial Aneurysms after Stent-Assisted Coil Embolization.

    Science.gov (United States)

    Nii, Kouhei; Aikawa, Hiroshi; Tsutsumi, Masanori; Eto, Ayumu; Iko, Minoru; Sakamoto, Kimiya; Inoue, Ritsuro; Mitsutake, Takafumi; Hanada, Hayatsura; Kazekawa, Kiyoshi

    2016-03-01

    Stent-assisted coil embolization (SACE) is used to address wide-necked or complex aneurysms. However, as they may recanalize after SACE, predictors of recanalization are needed. We investigated the relationship between follow-up angiographic results and the morphology of sidewall (SW) aneurysms in patients treated by SACE. Between September 2010 and September 2014, we performed 80 SACE procedures for SW intracranial aneurysms. Angiographic findings, obtained immediately after the procedure, 3-6 months thereafter, and when aneurysmal recanalization was suspected on MR angiogram scan, were recorded. Morphologically, the SW aneurysms were classified as "outside" (OS) and "partially inside" (PI) based on the curve of the axes of the proximal or distal parent artery with respect to the aneurysmal neck. Follow-up angiographic studies on OS- and PI SW aneurysms were compared. On the initial angiograms, we classified 42 aneurysms as OS and 38 as PI. Immediately after SACE, there was no significant difference in the angiographic findings on OS and PI aneurysms. However, on follow-up angiograms, there was a significant difference in the rate of spontaneous improvement (4 of 42 [OS] versus 21 of 38 [PI], P = .001). We performed additional coil embolization to treat 3 recanalized OS aneurysms. SW aneurysms classified morphologically as PI tended to occlude progressively even after incomplete occlusion by SACE. In contrast, aneurysms classified as OS must be observed carefully after SACE. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  19. Angiographic picture of soft tissue desmoid fibromas

    International Nuclear Information System (INIS)

    Nikitaev, N.S.; Kuznetsova, M.A.

    1987-01-01

    Arteriography was performed in 35 patients with soft tissue desmoid fibromas. Angiographic semiotics of this disease was described. The frequency of detectability of symptoms in the arterial, parenchymatous and venous phases was analyzed. A tumor in the arterial phase was shown to be of normevascular or moderately hypervascular type without noticeable winding of the nutrient arteries, such features of malignancy as lacunae and ''tumor'' vessels being absent. In the parenchymatous phase desmoid tumors were shown to accumulate moderately a contrast substance, a tumor contour at a vast length was ill defined and poorly marked from surrounding tissues. The venous phase was less noticeable and the time of its appearance was usually within normal. In general by most of its parameters the angiographic picture of agressive fibromatosis corresponded to that of benign tumors and could be used for differential diagnosis of desmoid fibromas and some types of tissue sarcomas

  20. Angiographic diagnosis and treatment of gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Park, Jae Hyung; Sung, Kyu Bo; Koo, Kyung Hoi; Bae, Tae Young; Chung, Eun Chul; Han, Man Chung

    1986-01-01

    Diagnostic angiographic evaluations were done in 33 patients with gastrointestinal bleeding for recent 5 years at Department of Radiology, Seoul National University Hospital. On 11 patients of them, therapeutic interventional procedures were made and the results were analysed. 1. In a total of 33 cases, there were 18 cases of upper GI bleeding and 15 cases of lower GI bleeding. The most frequent causes were peptic ulcer in the former and intestinal typhoid fever in the latter. 2. Bleeding sites were localized angiographically in 28 cases, so the detection rate was 85%. Four of the five angiographically negative cases were lower GI bleeding cases. 3. The most frequent bleeding site was left gastric artery (7/33). The next was ileocecal branch of superior mesenteric artery (6/33). 4. Among the 11 interventional procedures, Gelfoam embolization was done in 7 cases and Vasopressin infusion was tried in 4 cases. They were successful in 4 and 3 cases, suggesting 57% and 47% success rates respectively.

  1. Angiographic diagnosis and treatment of gastrointestinal bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hyung; Sung, Kyu Bo; Koo, Kyung Hoi; Bae, Tae Young; Chung, Eun Chul; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1986-02-15

    Diagnostic angiographic evaluations were done in 33 patients with gastrointestinal bleeding for recent 5 years at Department of Radiology, Seoul National University Hospital. On 11 patients of them, therapeutic interventional procedures were made and the results were analysed. 1. In a total of 33 cases, there were 18 cases of upper GI bleeding and 15 cases of lower GI bleeding. The most frequent causes were peptic ulcer in the former and intestinal typhoid fever in the latter. 2. Bleeding sites were localized angiographically in 28 cases, so the detection rate was 85%. Four of the five angiographically negative cases were lower GI bleeding cases. 3. The most frequent bleeding site was left gastric artery (7/33). The next was ileocecal branch of superior mesenteric artery (6/33). 4. Among the 11 interventional procedures, Gelfoam embolization was done in 7 cases and Vasopressin infusion was tried in 4 cases. They were successful in 4 and 3 cases, suggesting 57% and 47% success rates respectively.

  2. CT, MR and angiographic findings of hemangiopericytomas

    International Nuclear Information System (INIS)

    Lim, Soo Mee; Lee, Ho Kyu; Shin, Ji Hoon; Kim, Jae Kyun; Kim, Dae Hong; Choi, Choong Gon; Suh, Dae Chul

    1999-01-01

    Hemangiopericytoma(HP) exhibits its pathologic findings different from those of meningioma or other angiomatous tumor; and its clinical behavior is unique and prognosis worse than other cases. We reviewed the CT, MR and angiographic findings of HPs and evaluated differential radiologic points of comparison between typical meningiomas and meningeal HPs. MR(n=16), CT(n=5) and angiographic imaging(n=10) were performed in 18 patients(M:F = 12:6, mean age: 45 years) with histologically proven primary HPs. We evaluated the imaging findings of HPs with respect to site, shape, size, signal intensity, enhancement characteristics, vascular signal voids, calcification, bony and adjacent sinus involvement, and angiographic findings. HPs were meningeal in 14 cases and nonmeningeal in four. Meningeal HPs were located in the parasagittal region(n=8), convexity(n=3), intradural extramedullary space(n=1), choroid plexus(n=1), and olfactory groove(n=1). Nonmeningeal HPs were located in the masticator space(n=2), paraspinal area(n=1) and supraclavicular area(n=1). The mean maximal dimension of tumors was about 5.4cm and their shape was papillary(n=8) or lobulated(n=7). MR images showed high(n=13) or iso(n=3) signal intensities on T2W1, and heterogeneity on T2W1(n=9). Vascular signal voids in the mass were seen in all cases, while in two cases, CT scanning showed nodular dense calcification. Bone destruction was present in six cases, but no hyperostosis was found. In five cases, the superior sagittal sinus was involved. Angiographic images revealed highly vascular masses supplied by the internal carotid artery(n=5), external carotid artery(n=8), descending scapular artery(n=1) and radiculomedullary artery(n=1), with delayed tumor blush during the capillary and venous phase in which there was no arteriovenous shunt. HP is one of the extra-axial tumors in which there is hypervascularity, aggressive bony destruction arising in the meningeal and extrameningeal area, and heterogeneous high

  3. Accessory left gastric artery: angiographic anatomy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Soo; Lim, Hyung Guhn; Kim, Hong Soo; Jeon, Doo Sung [Presbyterian Medical Center, Chunju (Korea, Republic of); Chung, Jin Wook; Park, Jae Hyung [College of Medicine and the Institute of Radiation Medicine, Seoul National University, Seoul (Korea, Republic of); Song, Soon Young [Myongji Hospital, College of Medicine, Kwandong University, Seoul (Korea, Republic of)

    2000-09-01

    To evaluate the angiographic anatomy of the accessory left gastric artery (accLGA). We evaluated the angiographic findings of the accLGA in 50 patients (Angiostar; Siemens, Erlangen, Germany). Performing celiac and selective angiography in 50 and 34 patients, respectively. By means of celiac angiography, (1) site of origin, (2) anatomical course, (3) diameter, (4) degree of tortuosity, and (5) distal tapering were evaluated, while selective angiography was used to determine (1) arterial branching, (2) area of blood supply, and (3) patterns of gastric wall stain. Celiac angiography showed that the accLGA arose from the left hepatic artery (LHA) in 45 cases (90%) and from the proper hepatic artery in five (10%). If the accLGA arose from the LHA, its origin entirely depended on the branching pattern of the latter. It always arose from the lateral branch of the LHA furthest to the left and uppermost, and proximal to its umbilical point. The most common anatomical course of the accLGA, seen in 27 cases (54%), was between the S2 and S3 segmental branch. The diameter and degree of tortuosity of the accLGA were similar to those of adjacent intrahepatic branches in 21 (42%) and 33 cases (66%), respectively. The degree of tapering was less than that of adjacent intrahepatic vessel in 28 (56%). Selective angiography demonstrated esophageal branching of the acc LGA in 27 cases (79%), inferior phrenic arterial branching in three (9%), a mediastinal branch in one (3%), and hypervascularity of the lung in one (3%). In 15 cases (44%), bifurcation of the accLGA was recognized. The vascular territory of the accLGA was the gastric fundus together with the distal esophagus in 21 cases (62%), mainly the gastric fundus in six (18%), and mainly the distal esophagus in four (12%). The pattern of gastric mucosal stain was curvilinear wall in 31 cases (91%) and nodular in three (9%). A knowledge of the angiographic anatomy of the accLGA facilitates accurate recognition of this artery on

  4. Renal artery origins: best angiographic projection angles.

    Science.gov (United States)

    Verschuyl, E J; Kaatee, R; Beek, F J; Patel, N H; Fontaine, A B; Daly, C P; Coldwell, D M; Bush, W H; Mali, W P

    1997-10-01

    To determine the best projection angles for imaging the renal artery origins in profile. A mathematical model of the anatomy at the renal artery origins in the transverse plane was used to analyze the amount of aortic lumen that projects over the renal artery origins at various projection angles. Computed tomographic (CT) angiographic data about the location of 400 renal artery origins in 200 patients were statistically analyzed. In patients with an abdominal aortic diameter no larger than 3.0 cm, approximately 0.5 mm of the proximal part of the renal artery and origin may be hidden from view if there is a projection error of +/-10 degrees from the ideal image. A combination of anteroposterior and 20 degrees and 40 degrees left anterior oblique projections resulted in a 92% yield of images that adequately profiled the renal artery origins. Right anterior oblique projections resulted in the least useful images. An error in projection angle of +/-10 degrees is acceptable for angiographic imaging of the renal artery origins. Patients sex, site of interest (left or right artery), and local diameter of the abdominal aorta are important factors to consider.

  5. Clinical application of digital angiographic system DIGITEX2400

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Masumi; Tanaka, Shuji; Fujino, Yoshiyuki; Yasumi, Masayuki (Shimadzu Corp., Kyoto (Japan))

    1992-10-01

    Digital angiography (DA) has been of widespread use clinically, and it has attracted considerable attention in angiographic examination today. And under the condition of the spread of interventional angiography, not only high quality image but also ease of operation are required to the system. The clinical usefullness of digital angiographic system DIGITEX2400 are reported in this paper. (author).

  6. Clinical application of digital angiographic system DIGITEX2400

    International Nuclear Information System (INIS)

    Kawai, Masumi; Tanaka, Shuji; Fujino, Yoshiyuki; Yasumi, Masayuki

    1992-01-01

    Digital angiography (DA) has been of widespread use clinically, and it has attracted considerable attention in angiographic examination today. And under the condition of the spread of interventional angiography, not only high quality image but also ease of operation are required to the system. The clinical usefullness of digital angiographic system DIGITEX2400 are reported in this paper. (author)

  7. The angiographic demonstration of hepatic vein obstruction

    International Nuclear Information System (INIS)

    Zu Maoheng; Xu Hao; Li Guojun; Gu Yuming; Wei Ning; Wang Cheng; Xu Wei

    2004-01-01

    Objective: To evaluate the angiographic feature of hepatic vein obstruction. Methods Forty-five patients (male 23, female 22, age 9-54 years) suffered from hepatic vein obstruction. The inferior vena cavography and the hepatic venography were performed in all cases. Results: IVC was free in 37 patients with hepatic vein obstruction, both IVC and HV were obstructed in 8 patients. The local or long stenosis of IVC was found in 31 inferior vena cavography. The diameter of IVC was normal in 12 patients. The sign of membranous dome was found in hepatic vein orifice in 5 cases and in accessory hepatic vein orifice in 4 cases. Intrahepatic venous collaterals were found in 45 cases. Conclusion: Hepatic vein obstruction can be reproached primarily in inferior vena cavography, the membranous dome is a direct sign of membranous obstruction of HV and AHV in inferior vena cavography. The selected hepatic venography can provide reliable evidence to diagnose hepatic vein obstruction

  8. Angiographic features of rapidly involuting congenital hemangioma (RICH)

    Energy Technology Data Exchange (ETDEWEB)

    Konez, Orhan; Burrows, Patricia E. [Department of Radiology, Children' s Hospital Boston, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Mulliken, John B. [Division of Plastic Surgery, Children' s Hospital Boston, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Fishman, Steven J. [Department of Pediatric Surgery, Children' s Hospital Boston, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Kozakewich, Harry P.W. [Department of Pathology, Children' s Hospital Boston, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States)

    2003-01-01

    Rapidly involuting congenital hemangioma (RICH) is a recently recognized entity in which the vascular tumor is fully developed at birth and undergoes rapid involution. Angiographic findings in two infants with congenital hemangioma are reported and compared with a more common postnatal infantile hemangioma and a congenital infantile fibrosarcoma. Congenital hemangiomas differed from infantile hemangiomas angiographically by inhomogeneous parenchymal staining, large and irregular feeding arteries in disorganized patterns, arterial aneurysms, direct arteriovenous shunts, and intravascular thrombi. Both infants had clinical evidence of a high-output cardiac failure and intralesional bleeding. This congenital high-flow vascular tumor is difficult to distinguish angiographically from arteriovenous malformation and congenital infantile fibrosarcoma. (orig.)

  9. Angiographic findings of congenital vascular malformation in soft tissue

    International Nuclear Information System (INIS)

    Choi, Dae Seob; Park, Jae Hyung; Han, Joon Koo; Chung, Jin Wook; Moon, Woo Kyung; Han, Man Chung

    1994-01-01

    We evaluated the clinical, plain radiographic, and angiographic findings of congenital vascular malformation of the soft tissue. Retrospective analysis was performed in 36 patients. Pathological diagnosis was done in 25 patients by surgery and the others were clinically and angiographically diagnosed. On the basis of angiographic findings, we classified the lesions to three groups as arteriovenous malformation (AVM), hemangioma, and venous malformation. In pathologically proven 25 cases, we compared the angiographic diagnosis with the pathologic diagnosis. By angiographic classification, AVM was 13 cases, hemangioma 16 cases, and venous malformation 7 cases. The locations of the lesions were upper extremities in 14 cases, lower extremities in 20 cases, both extremities in 1 case, and back in 1 case. Clinical findings were bruit and thrill in 13 cases(12 AVMs,1 hemangioma) and varicosities in 16 cases(11 AVMs, 3 hemangiomas and 2 venous malformations). The varicosities in AVM were pulsating nature, but not in hemangioma and venous malformation. The concordance rate of the angiographic and pathologic diagnosis was 100%(6/6) in AVM, 71%(10/14) in hemangioma and 60% (3/5) in venous malformation. We think that angiography is an essential study for accurate diagnosis and appropriate treatment of congenital vascular malformation

  10. Angiographic diagnosis of the prehepatic portal hypertension

    International Nuclear Information System (INIS)

    Carnevali, G.; Brambilla, G.

    1981-01-01

    After the experience gained in the examination of more than 400 patients with portal hypertension, one can say that thrombosis is a factor not to be neglected. It appeared in 25% of all cases, in 50% of all cases as a cause of liver cirrhosis. The representation of the vena coeliaca mesentenica is essential for a reliable detection of thrombosis. Splenoportography is less frequently applied due to the known contraindications and is restricted to more demanding and complex problems. The detection of thrombotic changes is also important because such areas prohibit surgical measures such as by-passes. Also important is the preventive discovery of a portal thrombosis in the course of a complicated, bleeding liver cirrhosis. A pre-operative angiographic diagnosis is necessary in planned portocaval shunt procedures of cirrholic liver alterations. The surgeon has to know beforehand whether pyle thrombosis can be excluded or detected. In the latter case, a thrombotectomy has to be performed, which, however, does not impede good treatment results. (orig./MG) [de

  11. Angiographic diagnosis of the prehepatic portal hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Carnevali, G; Brambilla, G

    1981-01-01

    After the experience gained in the examination of more than 400 patients with portal hypertension, one can say that thrombosis is a factor not to be neglected. It appeared in 25% of all cases and in 50% of all cases as a cause of liver cirrhosis. The representation of the vena coeliaca mesentenica is essential for a reliable detection of thrombosis. Splenoportography is less frequently applied due to the known contraindications and is restricted to more demanding and complex problems. The detection of thrombotic changes is also important because such areas prohibit surgical measures such as by-passes. Also important is the preventive discovery of a portal thrombosis in the course of a complicated, bleeding liver cirrhosis. A pre-operative angiographic diagnosis is necessary in planned portocaval shunt procedures of cirrholic liver alterations. The surgeon has to know beforehand whether pyle thrombosis can be excluded or detected. In the latter case, a thrombotectomy has to be performed, which, however, does not impede good treatment results.

  12. Angiographic patterns of carotid-cavernous fistulas

    International Nuclear Information System (INIS)

    Georgieva, G.; Jekova, M.; Genov, P.; Hadjidekov, V.

    2006-01-01

    Full text: The aim of the study is to present our experience in angiographic evaluation of carotid-cavernous fistulas. 8 patients with carotid-cavernous fistula (6 men and 2 women, range of age from 15 to 62) are included in the study out of all undergone cerebral angiography for a four year period (1996 - 2000). All patients underwent CT brain examination, two out of 8 - MRI. Visualization of ipsi- and contra lateral cavernous sinus and ophthalmic vein dilatation are assessed. In all cases the communication between the internal carotid artery and the cavernous sinus has been assessed as direct. Near simultaneous visualization of the home internal carotid artery, the dilated ipsilateral cavernous sinus and dilated superior ophthalmic vein is found in 2 patients, simultaneous visualization of both cavernous sinuses - in two. In 1 patient the early visualization of the cavernous sinus through the fistula enabled visualization of ipsilateral main internal carotid artery from the contra lateral circulation through the communicating arteries.In 1 excessive contralateral cavernous sinus and contralateral superior ophthalmic vein dilatation is detected. In other 1 excessive flow to dilated ipsilateral cavernous sinus lead insufficient circulation in distal vessels. Digital subtraction Angiography remains the most suitable imaging method in carotid-cavernous fistula assessment regarding type of communication and level of following vessels morphology changes

  13. Clinical and angiographic characteristics of patients likely to have vulnerable plaques: analysis from the PROSPECT study.

    Science.gov (United States)

    Bourantas, Christos V; Garcia-Garcia, Hector M; Farooq, Vasim; Maehara, Akiko; Xu, Ke; Généreux, Philippe; Diletti, Roberto; Muramatsu, Takashi; Fahy, Martin; Weisz, Giora; Stone, Gregg W; Serruys, Patrick W

    2013-12-01

    This study sought to determine the clinical and angiographic variables that would identify patients with high-risk "vulnerable" coronary plaques. In the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study, in patients successfully treated for acute coronary syndrome (ACS), plaque composition, plaque burden, and minimal luminal area as detected by 3-vessel radiofrequency intravascular ultrasound (IVUS) imaging were associated with an increased risk of developing future events from untreated atherosclerotic lesions (vulnerable plaques). Whether baseline demographic and angiographic findings can be used to identify patients most likely to have vulnerable coronary plaques has not been examined. On the basis of 3-vessel radiofrequency IVUS imaging, patents in the PROSPECT trial were classified in 2 groups according to whether or not one or more untreated high-risk plaques were present, defined as having ≥2 high-risk features (a thin-cap fibroatheroma, plaque burden ≥70%, and/or minimal luminal area ≤4 mm(2)). The high-risk group (those with one or more high-risk lesions) had higher Framingham risk score (7.5 ± 3.4 vs. 6.9 ± 3.3; p = 0.04), more extensive coronary artery disease, and more nonculprit lesion-related cardiovascular events during the 3-year follow-up (hazard ratio: 2.63; 95% confidence interval: 1.62 to 3.66; p < 0.0001). However, demographic factors had poor discrimination in detecting high-risk patients (area under the curve 0.55), and discrimination was only slightly improved when angiographic variables were entered into the model (area under the curve 0.64). Clinical and angiographic characteristics had poor predictive accuracy in identifying patients with untreated high-risk plaques related to future adverse events. This finding highlights the potential value of comprehensive 3-vessel imaging assessment (either invasive or noninvasive) to evaluate plaque phenotype for more accurate risk

  14. Angiographic assessment of initial balloon angioplasty results.

    Science.gov (United States)

    Gardiner, Geoffrey A; Sullivan, Kevin L; Halpern, Ethan J; Parker, Laurence; Beck, Margaret; Bonn, Joseph; Levin, David C

    2004-10-01

    To determine the influence of three factors involved in the angiographic assessment of balloon angioplasty-interobserver variability, operator bias, and the definition used to determine success-on the primary (technical) results of angioplasty in the peripheral arteries. Percent stenosis in 107 lesions in lower-extremity arteries was graded by three independent, experienced vascular radiologists ("observers") before and after balloon angioplasty and their estimates were compared with the initial interpretations reported by the physician performing the procedure ("operator") and an automated quantitative computer analysis. Observer variability was measured with use of intraclass correlation coefficients and SD. Differences among the operator, observers, and the computer were analyzed with use of the Wilcoxon signed-rank test and analysis of variance. For each evaluator, the results in this series of lesions were interpreted with three different definitions of success. Estimation of residual stenosis varied by an average range of 22.76% with an average SD of 8.99. The intraclass correlation coefficients averaged 0.59 for residual stenosis after angioplasty for the three observers but decreased to 0.36 when the operator was included as the fourth evaluator. There was good to very good agreement among the three independent observers and the computer, but poor correlation with the operator (P definition of success was used. Significant differences among the operator, the three observers, and the computer were not present when the definition of success was based on less than 50% residual stenosis. Observer variability and bias in the subjective evaluation of peripheral angioplasty can have a significant influence on the reported initial success rates. This effect can be largely eliminated with the use of residual stenosis of less than 50% to define success. Otherwise, meaningful evaluation of angioplasty results will require independent panels of evaluators or

  15. Intracranial meningeal masson's hemangioma: CT and angiographic features

    International Nuclear Information System (INIS)

    Chang, Kee Hyun; Chi, Je Gen; Han, Man Chung; Cho, Byung Kyu; Kim, Hyun Jip

    1985-01-01

    Masson's hemangioma is a rare benign vascular condition with a papillary intravascular endothelial proliferation which may appear either as a primary form as a secondary form in a pre-existing vascular process. CT and angiographic features of 2 cases with Masson's hemangioma were presented. Both of them were located extra-axially in the posterior fossa. CT findings were not specific in both cases; One showed homogeneously enhancing mass, simulating meningioma. And the other demonstrated a multiocular rim enhancing mass. However, the angiographic features were rather characteristic; Both cases showed persistent vascular poolings of contrast media which were supplied form the meningeal vessels. Angiographic differential diagnosis of similar lesions in the posterior fossa is discussed

  16. Adult Moyamoya disease angiographic images evolutive characters and treatment methods

    International Nuclear Information System (INIS)

    Qian Jiangnan; Ling Feng

    2000-01-01

    Objective: To discuss the angiographic images with evolutional characters and the treatment methods of the Moyamoya disease. Methods: The clinical manifestations, the radiographic changes and the comparative analysis between medicine treatment and surgery treatment, together with the laboratory tests findings were analyzed in one cases adult Moyamoya disease during six years. Conclusions: The angiographic characteristics of MMD show the supplied artery trunk stenosis, and followed by occlusion, with later appearance of vascular smoking sign. Medical treatment proved to be of null. Direct or indirect intra or extra cranial vascular anastomosis are effective for treatment

  17. Mesenteric Castleman's disease: ultrasound, computed tomography and angiographic appearance

    International Nuclear Information System (INIS)

    Malara, F.A.; Price, D.; Fabiny

    2000-01-01

    The localized form of Castleman's disease is rare, and a mesenteric location is particularly unusual. A case of an asymptomatic young woman having the hyaline vascular type is presented and the ultrasound, computed tomography (CT) and angiographic features of the condition are demonstrated. Copyright (1999) Blackwell Science Pty Ltd

  18. Spontaneous coronary artery dissection: complete angiographic resolution without stenting

    Directory of Open Access Journals (Sweden)

    Alexandre Abizaid

    2007-09-01

    Full Text Available A case of spontaneous coronary artery dissection in a 49-year-oldwoman is presented. She did not present the classical cardiovascular riskfactors. Etiology and treatment are discussed. She underwent primarypercutaneous coronary intervention of the left anterior descendingartery with no stenting and had complete angiographic resolution.

  19. Angiographic diagnosis of hemorrhage tumours of the small intestine

    International Nuclear Information System (INIS)

    Vadon, G.; Ehngloner, L.; Petri, K.

    1980-01-01

    2 angiographic investigations in small intestine tumors, accompanied with hemorrhage are considered. Conclusion is made that the most suitable moment for estimation of small intestine hemorrhage, according to the proper and literature data, is selective angiography. Wide application of the technique for preoperative detection of gastro-inestinal hemorrhage is recommended

  20. Quantitative assessment of angiographic perfusion reduction using color-coded digital subtraction angiography during transarterial chemoembolization.

    Science.gov (United States)

    Wang, Ji; Cheng, Jie-Jun; Huang, Kai-Yi; Zhuang, Zhi-Guo; Zhang, Xue-Bin; Chi, Jia-Chang; Hua, Xiao-Lan; Xu, Jian-Rong

    2016-03-01

    The aim of this study was to develop a quantitative measurement of perfusion reduction using color-coded digital subtraction angiography (ccDSA) to monitor intra-procedural arterial stasis during TACE. A total number of 35 patients with hepatocellular carcinoma who had undergone TACE were enrolled into the study. Pre- and post-two-dimensional digital subtraction angiography scans were conducted with same protocol and post-processed with ccDSA prototype software. Time-contrast-intensity (CI[t]) curve was obtained by region-of-interest (ROI) measurement on the generated ccDSA image. Quantitative 2D perfusion parameters time to peak, area under the curve (AUC), maximum upslope, and contrast intensity peak (CI-Peak) derived from the ROI-based CI[t] curve for pre- and post-TACE were evaluated to assess the reduction of antegrade blood flow and tumor blush. Relationships between 2D perfusion parameters, subjective angiographic chemoembolization endpoint (SACE) scale, and clinical outcomes were analyzed. Area normalized AUC and CI-Peak revealed significant reduction after the TACE (P SACE level III and a reduction ranging from 60% to 70% was equivalent to SACE level IV. For intermediate reduction (SACE level III), better tumor response was found after TACE rather than a higher reduction (SACE level IV). ccDSA application provides an objective approach to quantify the perfusion reduction and subjectively evaluate the arterial stasis of antegrade blood flow and tumor blush caused by TACE.

  1. Staff dosimetry and risk assessment during digestive and angiographic examinations

    International Nuclear Information System (INIS)

    Pages, J.; Osteaux, M.

    2001-01-01

    The use of ionizing radiation in medical applications involves not only a risk for the patient, but also for the staff which executed the related examinations. The dose to the forehead, neck, fingers and wrist of a radiologist and an assisting nurse were measured with thermoluminescent dosimeters during angiographic and digestive examinations respectively. Dose to eye lenses and effective dose were estimated for a working period of one year. Effective doses were under the established limit of 20 mSv per year. Nurse eye lens dose was higher than the limit of 150 mSv. Differences of a factor of 3.8 were observed between nurse and radiologist doses. Angiographic procedures are considered as high risk examinations, however, digestive examinations can have a higher risk than interventional procedures. (author)

  2. Development of DIGITEXαPlus digital angiographic system

    International Nuclear Information System (INIS)

    Imanishi, Tetsuo; Miura, Yusuke; Sasaki, Osamu; Furuyama, Makoto; Yasumi, Masayuki

    2001-01-01

    The functions required of digital angiographic (DA) systems have been noticeably changing with the recent popularization of the technique of interventional radiology (IVR) in the field of angiography. We have developed a new digital angiographic system, named the DIGITEXαPlus, which is designed to meet the requirements of the latest IVR technologies. The DIGITEXαPlus system is equipped with a high-performance one-million-pixel CCD camera, a newly developed F.P.O. (fluoro-power optimizer), and a contrast-priority radiography control system, which combine together to provide high quality of images both in fluoroscopy and in fluorography. In this new system, a low-dose pulsed fluoroscopy method, employed as standard, minimizes the X-ray doses to patients, and an image controller (IVR MASTER) of a joy stick type provides more diversified functions that its predecessors. These two features enhance the reliability, and simplifies the operation, of the IVR system as a whole. (author)

  3. Persistent sciatic artery: clinical, embryologic, and angiographic features

    International Nuclear Information System (INIS)

    Mandell, V.S.; Jaques, P.F.; Delaney, D.J.; Oberheu, V.

    1985-01-01

    The persistent sciatic artery is a rare but interesting and clinically pertinent vascular anomaly that may present as a buttock aneurysm or as an ischemic or embolic disease. Its correct angiographic diagnosis depends on recognition of an abnormally large internal iliac artery, appropriate injection and adequate timing to fill and follow flow into the large vessel, and recognition and differentiation of the tapering superficial femoral artery from routine occlusive disease so that an accurate picture of lower leg runoff is provided

  4. Clinical and angiographic outcomes after intracoronary bare-metal stenting.

    Directory of Open Access Journals (Sweden)

    I-Chang Hsieh

    Full Text Available BACKGROUND: Data from a large patient population regarding very long-term outcomes after BMS implantation are inadequate. This study aimed to evaluate the very long-term (8-17 years clinical and long-term (3-5 years angiographic outcomes after intracoronary bare-metal stenting (BMS. METHODS AND RESULTS: From the Cardiovascular Atherosclerosis and Percutaneous TrAnsluminal INterventions (CAPTAIN registry, a total of 2391 patients with 2966 lesions treated with 3190 BMSs between November 1995 and May 2004 were evaluated. In total, 1898 patients with 2364 lesions, and 699 patients with 861 lesions underwent 6-month and 3- to 5- year angiographic follow-up, respectively. During a mean follow-up period of 149 ± 51 months, 18.6% of the patients died (including 10.8% due to cardiac death, 6.1% developed reinfarction, 16.2% had target lesion revascularization (including 81% of the patients within the first year, 14.5% underwent new lesion stenting (including 72% of the patients after 3 years, 2.4% underwent coronary bypass surgery, and 1.6% had definite stent thrombosis. The overall cardiovascular event-free survival rate was 58.5%. The 6-month angiographic study indicated a 20% restenosis rate. The minimal luminal diameter increased from 0.65 ± 0.44 mm to 3.02 ± 0.46 mm immediately after stenting, decreased to 2.06 ± 0.77 mm at the 6-month follow-up, and increased to 2.27 ± 0.68 mm at the 3- to 5-year follow-up. CONCLUSIONS: This study provides clinical and angiographic results from a large population of patients who underwent BMS implantations after a long-term follow-up period (149 ± 51 months. The progression of coronary atherosclerosis developed over time, and presented with new lesion required stent implantation. The follow-up angiographic findings reconfirmed the late and sustained improvement in luminal diameter between 6 months and 3-5 years.

  5. Angiographic Guidewire with Measuring Markers: Design and Clinical Experience

    International Nuclear Information System (INIS)

    Kamei, Seiji; Ishiguchi, Tsuneo; Murata, Katsuhito; Matsuda, Joe; Ohno, Ryota; Kimura, Junko; Nakamura, Atsushi; Ohno, Kazuko; Kawamura, Toshiki; Ikeda, Mitsuru

    2006-01-01

    Purpose. We have developed an angiographic guidewire with measuring markers to determine accurately how far a guidewire is inserted within a catheter. We investigated whether use of this guidewire reduces the risk of vascular injury and the fluoroscopic time during guidewire manipulations. Methods. Four markers were put on the surface of the guidewire at 80, 100, 110, and 120 cm from the tip. The actual lengths of 54 catheters from seven manufacturers were measured and compared with the nominal lengths. Sixty consecutive patients who underwent angiography were randomized into two groups: in one group guidewires with surface markers were used (marker group) and in the other group, conventional guidewires (control group). For each guidewire insertion, the fluoroscopic time before the guidewire was pushed forward into the vessel lumen was recorded. The number of occasions on which unintentionally the guidewire had already been pushed out of the catheter at the start of fluoroscopy was also evaluated. Results. The actual lengths of all catheters were greater than the nominal lengths by 1.0-11.0 cm. Mean fluoroscopic time for each guidewire insertion was 3.3 sec in the marker group and 5.7 sec in the control group (p < 0.05). Guidewires were unintentionally pushed out of the catheters without fluoroscopy three times (3.6%), in each case in the control group. Conclusion. The guidewire with measuring markers is effective for enhancing safety and in reducing fluoroscopic radiation during angiographic procedures. It is recommended that operators be aware that actual lengths of catheters may vary significantly from the nominal lengths listed; they should be aware of this with any guidewire, but particularly with the angiographic measuring guidewire

  6. Clinical-pathological-angiographic correlations following transluminal atherectomy

    International Nuclear Information System (INIS)

    Althaus, S.J.; Maynar, M.; Reyes, R.; Pulido-Duque, J.M.; Casal, G.; Hunter, D.W.; Castaneda-Zuniga, W.R.; Amplatz, K.

    1989-01-01

    Following percutaneous atherectomy, arterial and catheter diameter relationships were correlated with angiographic and ankle-arm index results. There was a greater amount of tissue removed, improved luminal reconstitution, and ankle-arm index in lesions where the catheter and arterial diameters were equal or within 0.5 mm. Excluding lesions requiring angioplasty, 77% of our lesions had less than 30% residual stenosis; including lesions requiring concomitant angioplasty, the initial overall patency was 93%, with a 1-year patency rate of 92.5%. This study indicates that adequate matching of the atherectomy catheter diameter to the arterial diameter is necessary to optimize tissue removal and clinical results

  7. Effective dose and dose to crystalline lens during angiographic procedures

    International Nuclear Information System (INIS)

    Pages, J.

    1998-01-01

    The highest radiation doses levels received by radiologists are observed during interventional procedures. Doses to forehead and neck received by a radiologist executing angiographic examinations at the department of radiology at the academic hospital (AZ-VUB) have been measured for a group of 34 examinations. The doses to crystalline lens and the effective doses for a period of one year have been estimated. For the crystalline lens the maximum dose approaches the ICRP limit, that indicates the necessity for the radiologist to use leaded glasses. (N.C.)

  8. Surgical Management of Juvenile Nasopharyngeal Angiofibroma Without Angiographic Embolization

    Directory of Open Access Journals (Sweden)

    Raja Ahmad

    2008-10-01

    Full Text Available Juvenile nasopharyngeal angiofibroma (JNA is a rare benign neoplasm that occurs almost exclusively in the nasopharynx of adolescent males. Surgery remains the primary treatment of choice. JNA has always presented a management challenge to surgeons because of its vascular nature, site of occurrence, and local tissue destruction. The surgical approaches are either standard open method which include external or intraoral incisions, or the recent advanced approach, i.e. via using the endonasal endoscope. It is widely accepted that the use of preoperative angiographic embolization reduces the occurrence of intraoperative bleeding and facilitates tumour removal. However, angiographic embolization is not available at all centres. The purpose of this article is to present our experience with five patients diagnosed with JNA who were resected without embolization, using various surgical approaches. Two tumours were removed via endonasal endoscopic surgery. None of the tumours were embolized prior to surgery. We highlight the preoperative evaluation of tumour extent, using both computed tomography (CT and magnetic resonance angiography, and the importance of temporary clamping of the external carotid artery intraoperatively. Our results suggest that the latter procedure is a safe and effective means of facilitating surgery and reducing intraoperative bleeding.

  9. Angiographic features of 26 children with Takayasu's arteritis

    International Nuclear Information System (INIS)

    McCulloch, M.; Goddard, E.; Sinclair, P.; Andronikou, S.; Mandelstam, S.; Beningfield, S.J.; Lawrenson, J.; Millar, A.J.W.

    2003-01-01

    Background: Takayasu's arteritis (TA) is a chronic idiopathic inflammatory disease affecting primarily the aorta, its proximal branches and the pulmonary arteries Objectives: To retrospectively review the angiograms of children with TA so as to describe the patterns of vascular involvement. Patients and methods: Twenty-six children with TA who differed from most other studies in that almost all of them presented with hypertension, reflecting the incidence of abdominal aortic and renal artery involvement. Results: The most consistent finding was stenosis of the aorta. Marginal irregularity/undulation of the aorta was also a useful angiographic diagnostic feature in subtle disease. The incidence of aneurysms was high compared to other studies and both fusiform and saccular aneurysms were encountered. Percutaneous transluminal angioplasty (PTA) was successful in all eight patients in whom it was performed. MRI, CT angiography and US are discussed as less invasive imaging alternatives. TA is a significant cause of renovascular hypertension in children in South Africa where there is a high incidence of tuberculous infection. Knowledge of the angiographic features and pattern of aortic involvement is essential for diagnosis and initiation of early and appropriate treatment, including PTA. (orig.)

  10. Transvenous embolization of cavernous sinus dural arteriovenous fistula via angiographic occlusive inferior petrous sinus

    Directory of Open Access Journals (Sweden)

    Chao-Bao Luo

    2015-09-01

    Conclusion: Angiographic occlusive IPS of CSDAVF may be related to true occlusion of IPS or patent IPS with compartment of the IPS-CS. There is no statistically significant difference in procedural times for these two different fistula anatomies. Transvenous embolization via angiographic occlusive IPS is a safe and effective method to manage CSDAVFs.

  11. A comparison of chemoembolization endpoints using angiographic versus transcatheter intraarterial perfusion/MR imaging monitoring.

    Science.gov (United States)

    Lewandowski, Robert J; Wang, Dingxin; Gehl, James; Atassi, Bassel; Ryu, Robert K; Sato, Kent; Nemcek, Albert A; Miller, Frank H; Mulcahy, Mary F; Kulik, Laura; Larson, Andrew C; Salem, Riad; Omary, Reed A

    2007-10-01

    Transcatheter arterial chemoembolization (TACE) is an established treatment for unresectable liver cancer. This study was conducted to test the hypothesis that angiographic endpoints during TACE are measurable and reproducible by comparing subjective angiographic versus objective magnetic resonance (MR) endpoints of TACE. The study included 12 consecutive patients who presented for TACE for surgically unresectable HCC or progressive hepatic metastases despite chemotherapy. All procedures were performed with a dedicated imaging system. Angiographic series before and after TACE were reviewed independently by three board-certified interventional radiologists. A subjective angiographic chemoembolization endpoint (SACE) classification scheme, modified from an established angiographic grading system in the cardiology literature, was designed to assist in reproducibly classifying angiographic endpoints. Reproducibility in SACE classification level was compared among operators, and MR imaging perfusion reduction was compared with SACE levels for each observer. Twelve patients successfully underwent 15 separate TACE sessions. SACE levels ranged from I through IV. There was moderate agreement in SACE classification (kappa = 0.46 +/- 0.12). There was no correlation between SACE level and MR perfusion reduction (r = 0.16 for one operator and 0.02 for the other two). Angiographic endpoints during TACE vary widely, have moderate reproducibility among operators, and do not correlate with functional MR imaging perfusion endpoints. Future research should aim to determine ideal angiographic and functional MR imaging endpoints for TACE according to outcome measures such as imaging response, pathologic response, and survival.

  12. Spontaneous regression of cerebral arteriovenous malformations: clinical and angiographic analysis with review of the literature

    International Nuclear Information System (INIS)

    Lee, S.K.; Vilela, P.; Willinsky, R.; TerBrugge, K.G.

    2002-01-01

    Spontaneous regression of cerebral arteriovenous malformation (AVM) is rare and poorly understood. We reviewed the clinical and angiographic findings in patients who had spontaneous regression of cerebral AVMs to determine whether common features were present. The clinical and angiographic findings of four cases from our series and 29 cases from the literature were retrospectively reviewed. The clinical and angiographic features analyzed were: age at diagnosis, initial presentation, venous drainage pattern, number of draining veins, location of the AVM, number of arterial feeders, clinical events during the interval period to thrombosis, and interval period to spontaneous thrombosis. Common clinical and angiographic features of spontaneous regression of cerebral AVMs are: intracranial hemorrhage as an initial presentation, small AVMs, and a single draining vein. Spontaneous regression of cerebral AVMs can not be predicted by clinical or angiographic features, therefore it should not be considered as an option in cerebral AVM management, despite its proven occurrence. (orig.)

  13. Computer tomographic and angiographic studies of histologically confirmed intrahepatic masses

    International Nuclear Information System (INIS)

    Janson, R.; Lackner, K.; Paquet, K.J.; Thelen, M.; Thurn, P.

    1980-01-01

    The computer tomographic and angiographic findings in 53 patients with intrahepatic masses were compared. The histological findings show that 17 were due to echinococcus, 12 were due to hepatic carcinoma, ten were metastases, five patients had focal nodular hyperplasia, three an alveolar echinococcus and there were three cases with an haemangioma of the liver and a further three liver abscesses. Computer tomography proved superior in peripherally situated lesions, and in those in the left lobe of the liver. Arteriography was better at demonstrating lesions below 2 cm in size, particularly vascular tumours. As a pre-operative measure, angiography is to be preferred since it is able to demonstrate anatomic anomalies and variations in the blood supply, as well as invasion of the portal vein or of the inferior vena cava. (orig.) [de

  14. Computer tomographic and angiographic studies of histologically confirmed intrahepatic masses

    Energy Technology Data Exchange (ETDEWEB)

    Janson, R.; Lackner, K.; Paquet, K.J.; Thelen, M.; Thurn, P.

    1980-06-01

    The computer tomographic and angiographic findings in 53 patients with intrahepatic masses were compared. The histological findings show that 17 were due to echinococcus, 12 were due to hepatic carcinoma, ten were metastases, five patients had focal nodular hyperplasia, three an alveolar echinococcus and there were three cases with an haemangioma of the liver and a further three liver abscesses. Computer tomography proved superior in peripherally situated lesions, and in those in the left lobe of the liver. Arteriography was better at demonstrating lesions below 2 cm in size, particularly vascular tumours. As a pre-operative measure, angiography is to be preferred since it is able to demonstrate anatomic anomalies and variations in the blood supply, as well as invasion of the portal vein or of the inferior vena cava.

  15. Angiographic examinations with the medium size technique (70 mm films)

    International Nuclear Information System (INIS)

    Heuck, F.; Reichardt, W.

    1981-01-01

    The applicability of medium-size technique was tested in angiographic examinations of thoracic and abdominal organs. By means of full-size image intensifiers it is possible to carry out organ angiography, and by means of a pace control mechanism for the patient transport, the angiography of the extremities can be realized. Examples are given illustrate the informational value in cases where the arial and venous vascular systems of organs and extremities are concerned. The particular advantages for functional analyses of organ circulatory systems in cases of angiography are described. Two factors of importance are pointed out: the reduction of the exposure to irradiation for the patient on the one hand, and the increasing film prices on the other hand. The authors demand to overcome the psychological problems arising in the medical working groups where the medium-size technique shall be introduced into routine diagnostics. (orig./APR) [de

  16. A characteristic of angiographic cone-beam CT

    International Nuclear Information System (INIS)

    Takase, Tadashi; Take, Toshio; Nakazawa, Yasuo; Kinouchi, Katsunori

    2009-01-01

    Angiographic cone-beam CT, called DynaCT by SIEMENS, is a 3D imaging tool reconstructed from projection data by a rotational C-arm with a flat panel detector. It can visualize low-contrast objects such as soft tissue or small vessels as well as high-contrast structures such as enhanced vessels or bone. We need to understand its image characteristics and dose distribution during 200 degree rotation around a patient. In this research, we evaluated fundamental characteristics and dose effectiveness for optimized clinical images. DynaCT, including soft tissue information and isochronal voxel data along the z-axis, could provide enough CT-like image quality for interventional radiology (IVR) use. In addition, evaluation of accumulated dose distribution helped us to predict and avoid the occurrence of radiodermatitis. Thus, DynaCT is useful as a support and navigation tool for IVR. (author)

  17. Angiographic prevalence and pattern of coronary artery disease in women.

    Science.gov (United States)

    Ezhumalai, Babu; Jayaraman, Balachander

    2014-01-01

    There are not many studies describing the prevalence and pattern of "coronary artery disease" (CAD) in women undergoing "coronary angiography" (CAG). Hence, uncertainty thrives with regard to the angiographic prevalence and pattern of CAD in women. Our objective was to study the prevalence and pattern of CAD among women undergoing CAG. Data of 500 women who underwent CAG for suspected CAD over 3 years were retrospectively analyzed. They were classified into young group (age right coronary artery. Bifurcation lesion involving distal left main coronary artery is the most prevalent pattern of LMD. There has been a change with regard to clinical presentation and onset of risk factors for CAD at young age, but the load of atherosclerotic burden and pattern of involvement of coronary arteries have not changed in women. Copyright © 2014 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  18. Radioembolization with 90Y Microspheres: Angiographic and Technical Considerations

    International Nuclear Information System (INIS)

    Lewandowski, Robert J.; Sato, Kent T.; Atassi, Bassel; Ryu, Robert K.; Nemcek, Albert A.; Kulik, Laura; Geschwind, Jean-Francois; Murthy, Ravi; Rilling, William; Liu, David; Bester, Lourens; Bilbao, Jose Ignacio; Kennedy, Andrew S.; Omary, Reed A.; Salem, Riad

    2007-01-01

    The anatomy of the mesenteric system and the hepatic arterial bed has been demonstrated to have a high degree of variation. This is important when considering pre-surgical planning, catheterization, and trans-arterial hepatic therapies. Although anatomical variants have been well described, the characterization and understanding of regional hepatic perfusion in the context of radioembolization have not been studied with great depth. The purpose of this review is to provide a thorough discussion and detailed presentation of the angiographic and technical aspects of radioembolization. Normal vascular anatomy, commonly encountered variants, and factors involved in changes to regional perfusion in the presence of liver tumors are discussed. Furthermore, the principles described here apply to all liver-directed transarterial therapies

  19. Clinical Investigation of Radiation Retinopathy Fundus and Fluorescein Angiographic Features

    Institute of Scientific and Technical Information of China (English)

    LiMei; QiuGT

    1999-01-01

    Purpose:To investigate the fundus and fluorescein angiographic features in the patients with radiation retinopathy.Clinical Materials:Color fundus photography and/or fluorescein angiography from 13 patients with nasopharyngeal carcinomas received external beam radiation were retrospectively analyzed.Reslts:In this study,26 damaged eyes of 13 patients eveloped some degree of radiation retinopathy.The earliest and most common finding was macular microvascular changes (microaneurysms and/or telangiectasia),which was observed in 100%(26/26)of the eyes.Intraretinal hemorrhages,macular capillary nonperfusion,and macular edema were noted in 84%,50%,and 42% of the eyes,respectively.Conclusions:Radiation retinopathy is common after external beam radiation of nasopharyngeal carcinomas.The prominent changes include maular microvascular changes,intraretinal hemorrhages and macular capillary nonperfusion.

  20. Clinical-angiographic correlations in 132 patients with megadolichovertebrobasilar anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Resta, M; Gentile, M A; Di Cuonzo, F; Vinjau, E; Brindicci, D; Carella, A

    1984-05-01

    We have found numerous case reports, but no systematic study of the megadolichovertebrobasilar anomaly (MDVBA). The purpose of this paper is to evaluate the relationships between arterial shifts of the vertebro-basilar system and neurological findings in the posterios fossa in our series of 132 cases. We found a high percentage (77.3%) of angiographic-clinical correlations having evaluated the arterial shifts, measured in mm, of the vertebro basilar system in a frontal and a sagittal plane and concluded that the greater the degree of dislocation, the greater the number of Istituto di Radiologia Universita degli studi of Bari, positive cases. Nevertheless it is not possible to predetermine the presence of particular neurosymptomathology related to arterial dislocation degrees.

  1. Angiographic evaluation of response to preoperative chemotherapy in osteosarcoma

    International Nuclear Information System (INIS)

    Carrasco, C.H.; Charnsangavej, C.; Richii, W.; Wallace, S.; Chawla, S.P.; Raymond, A.K.; Murray, J.A.; Benjamin, R.S.

    1986-01-01

    Preoperative chemotherapy for osteosarcoma facilitates local resection for limb salvage and serves as an in vivo chemosensitivity assay. Arteriograms obtained with each intraarterial course of cisplatin in 79 patients with osteosarcoma were evaluated. Complete remission was defined as complete or nearly complete disappearance of tumor vascularity after treatment. A minimal decrease, no change, or an increase in tumor vascularity was not considered a response. If a complete remission is assumed to represent ≥ 90% histologic tumor necrosis which correlates with prolonged disease-free survival, the sensitivity of an angiographic complete remission was 95%, the specificity was 58%, the predictive value of a negative study was 90%, and the predictive value of a positive study was 75%. Angiography is the best clinical technique for evaluating the therapeutic response in osteosarcoma. Results correlate well with the degree of tumor necrosis, particularly in respect to significant residual viable tumor

  2. Unilateral renal agenesia in the angiographic material and renovascular hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Stojanov, D.; Lovasic, I.; Dujmovic, M.; Bobinac, D.

    1987-06-01

    Analysis of 1216 abdominal aortographies and selective renovasographies undertaken at the Institute of Radiology, Clinical Hospital Centre Rijeka during the period 1979-1985, was performed. 39 (3,2%) unilateral renal agenesias were established, a percentage that is significantly higher than reported by other authors. Analysis of all angiographic parameters of a single kidney was also worked out. A significanlty high percentage (66,7%) of hypertension was diagnosed in this group. Congenital renal failures make their appearance in the early embryological development and are discovered, if compatible with life, most frequently at an advanced age. Statistical data on the frequency during a lifetime are less reliable because a great number of anomalies are never discovered during a person's life. The etiology of variations and congenital failure of renal arteries is unknown in 90% of the cases, and most of the malformations are without characteristic symptomatology. Since the anatomic relations in anomalous kidney are disturbed, the sign of the disease can develop atypical forms causing frequent errors in diagnosis. The kidney is supplied by numerous lateral branches of the medial sacral artery, i.e. the aorta, during embryological development. Later, some of them degenerate or mutually connect themselves, and the definitive kidney has been usually penetrated by only one artery and one vein on the same side (1). If this is not so, i.e. when the obliterations of caudal metanephogenic arteries are only partially present, then the renal arteries emerge from the iliac or lumbar arteries (2,3). Bilateral renal agenesia is extreme and incompatible with life, and hence of small clinical importance. Unilateral agenesia makes its appearance according to various statistics and authors from the obductional materials in ratio 1:1000 (4,5), clinical ones 1:5000 (6, 7, 8) and the angiographically 1:76(9), more exactly 1:35 cases (10).

  3. Unilateral renal agenesia in the angiographic material and renovascular hypertension

    International Nuclear Information System (INIS)

    Stojanov, D.; Lovasic, I.; Dujmovic, M.; Bobinac, D.

    1987-01-01

    Analysis of 1216 abdominal aortographies and selective renovasographies undertaken at the Institute of Radiology, Clinical Hospital Centre Rijeka during the period 1979-1985, was performed. 39 (3,2%) unilateral renal agenesias were established, a percentage that is significantly higher than reported by other authors. Analysis of all angiographic parameters of a single kidney was also worked out. A significanlty high percentage (66,7%) of hypertension was diagnosed in this group. Congenital renal failures make their appearance in the early embryological development and are discovered, if compatible with life, most frequently at an advanced age. Statistical data on the frequency during a lifetime are less reliable because a great number of anomalies are never discovered during a person's life. The etiology of variations and congenital failure of renal arteries is unknown in 90% of the cases, and most of the malformations are without characteristic symptomatology. Since the anatomic relations in anomalous kidney are disturbed, the sign of the disease can develop atypical forms causing frequent errors in diagnosis. The kidney is supplied by numerous lateral branches of the medial sacral artery, i.e. the aorta, during embryological development. Later, some of them degenerate or mutually connect themselves, and the definitive kidney has been usually penetrated by only one artery and one vein on the same side (1). If this is not so, i.e. when the obliterations of caudal metanephogenic arteries are only partially present, then the renal arteries emerge from the iliac or lumbar arteries (2,3). Bilateral renal agenesia is extreme and incompatible with life, and hence of small clinical importance. Unilateral agenesia makes its appearance according to various statistics and authors from the obductional materials in ratio 1:1000 (4,5), clinical ones 1:5000 (6, 7, 8) and the angiographically 1:76(9), more exactly 1:35 cases (10). (orig.)

  4. Clinical presentations and MRI findings of angiographically occult vascular malformations

    International Nuclear Information System (INIS)

    Kida, Yoshihisa; Kobayashi, Tatsuya; Tanaka, Takayuki; Oyama, Hirofumi; Iwakoshi, Takayasu

    1994-01-01

    Various clinical features as well as MRI findings of AOVM (angiographically occult vascular malformation) were studied. Amongst out patients, since January 1988, there have been 30 cases of symptomatic AOVM (20 males, 10 females) including 4 cases with multiple lesions. The age ranged from 3 to 60 years of age, with a mean of 33.4 years. The locations of symptomatic lesions were in the cerebral hemisphere (15), the thalamus (4), the brain stem (8) and in the cerebellum (3). The initial presentations of these 30 cases were either by hemorrhage (18), convulsive seizure (9) or by progressive neurological deficits (3). The initial presentation was not related to the patient's age and the size of the lesion, but apparently related to the location of AOVM. Most of the lesions in the cerebral hemisphere presented seizures, but all of the lesions in the thalamus, the brain stem and the cerebellum disclosed hemorrhage as an initial presentation. In fact it was noticed that brain stem lesions tend to cause repetitive hemorrhage in a relatively short period. AOVM lesions were clearly visualized with T2-weighted MRI images, consisting of high intensity cores with surrounding low intensity rims. Most of the symptomatic lesions were partially enhanced by Gd-DTPA with varied intensity. Dynamic changes in size and enhancement pattern on MRI were occasionally seen, usually accompanied with episodes such as hemorrhage or neurological deterioration. Although AOVMs were angiographically negative some strands indicating draining veins were observed on MRI in several cases. In contrast, none of the nonsymptomatic lesions (22 lesions) demonstrated enhancement effects with Gd-DTPA. (author)

  5. CLINICAL AND ANGIOGRAPHIC PROFILE OF PATIENTS WITH COMPLETE HEART BLOCK

    Directory of Open Access Journals (Sweden)

    Kavya Pingali

    2017-05-01

    Full Text Available BACKGROUND The angiographic findings and prognosis of patients with Complete Heart Block (CHB remain unclear. Thus, we aimed to study the clinical profile, risk factors, angiographic distribution and in-hospital outcomes of patients with complete heart block. MATERIALS AND METHODS This was a prospective, single-centred study which included 100 patients who came to the emergency department with CHB. Routine blood investigations including serum electrolytes were done. Coronary angiogram was done and lesions were assessed. Temporary pacemaker was implanted followed by permanent pacemakers in required patients, and in-hospital complications were noted down. RESULTS Commonest age group was above 60 years (75%. The patients were predominantly males. Most common presentation was chest pain (60%; there was regional wall motion abnormality in 30% patients. Degenerative complete heart block was seen in 34% patients, diphtheric myocarditis in 15%, hypokalaemic in 15%, dilated cardiomyopathy in 2%. Of total 53 patients had AV block, 14 had bifascicular block, 23 had LBBB, 6 had RBBB, 3 had Mobitz I and 1 had Mobitz II. Inferior wall myocardial infarction (MI was pervasively present in patients. Temporary pacemakers were implanted in 6 patients and permanent pacemakers in 43 patients. In-hospital outcomes constituted of complication like cardiogenic shock (10% and death (26%. The patients who died either had 80% -90% stenosis in RCA, triple vessel disease, ostioproximal LAD occlusion or diphtheric myocarditis. CONCLUSION Complete heart block was majorly associated with advanced age and inferior wall MI, virtually caused by dominant RCA occlusion. The in-hospital mortality was significantly higher in the patients with CHB.

  6. Angiographic differentiation of type of ventricular septal defects

    International Nuclear Information System (INIS)

    Cheon, Mal Soon; Park, Hee Young; Kim, Yang Sook

    1989-01-01

    Defects of the ventricular septum are the commonest type of congenital cardiac malformations. A classification with axial angiography of the subtypes of ventricular septal defects is proposed on the study of 126 patients with defects of the ventricular septum. The results were as follows: 1. The incidence of the ventricular septal defects was 39.6% of congenital heart malformation. 2. The sex distribution of cases were 70 males and 56 females, the age ranged from 13 months to 26 years. 3. Angiographic features seen by axial angiography were as follows: a. Perimembranous defects as seen on long axial view of left ventriculogram were in continuity wity aortic valve. The relation of the defect to the tricuspid valve allows distinction of the extension of the preimembranous defect toward inlet, trabecular, or infundibular zones. This relation was determined angiographically, using the course of the contrast medium from the left ventricle through the ventricular septal defect, opacifying the right ventricle. In inlet excavation, the shunted blood opacified the recess between septal leaflet of tricuspid valve and interventricular septum in early phase, in infundibular excavation, opacified the recess between anterior leaflet of tricuspid valve and anterior free wall of right ventricle and in trabecular excavation, the shunted blood traversed anterior portion of tricuspid valve ring, opacified trabecular portion of right ventricle. b. Muscular defects were separated from the semilunar and atrioventricular valves. c, Subarterial defects were related to both semilunar valves, and they were best demonstrated on the elongated right anterior oblique view of the left ventriculogram. d. Total infundibular defects were profiled in right anterior oblique 30 and long axial view, subaortic in location in both views

  7. Imaginary time density-density correlations for two-dimensional electron gases at high density

    Energy Technology Data Exchange (ETDEWEB)

    Motta, M.; Galli, D. E. [Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Moroni, S. [IOM-CNR DEMOCRITOS National Simulation Center and SISSA, Via Bonomea 265, 34136 Trieste (Italy); Vitali, E. [Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795 (United States)

    2015-10-28

    We evaluate imaginary time density-density correlation functions for two-dimensional homogeneous electron gases of up to 42 particles in the continuum using the phaseless auxiliary field quantum Monte Carlo method. We use periodic boundary conditions and up to 300 plane waves as basis set elements. We show that such methodology, once equipped with suitable numerical stabilization techniques necessary to deal with exponentials, products, and inversions of large matrices, gives access to the calculation of imaginary time correlation functions for medium-sized systems. We discuss the numerical stabilization techniques and the computational complexity of the methodology and we present the limitations related to the size of the systems on a quantitative basis. We perform the inverse Laplace transform of the obtained density-density correlation functions, assessing the ability of the phaseless auxiliary field quantum Monte Carlo method to evaluate dynamical properties of medium-sized homogeneous fermion systems.

  8. A simple method to calculate first-passage time densities with arbitrary initial conditions

    Science.gov (United States)

    Nyberg, Markus; Ambjörnsson, Tobias; Lizana, Ludvig

    2016-06-01

    Numerous applications all the way from biology and physics to economics depend on the density of first crossings over a boundary. Motivated by the lack of general purpose analytical tools for computing first-passage time densities (FPTDs) for complex problems, we propose a new simple method based on the independent interval approximation (IIA). We generalise previous formulations of the IIA to include arbitrary initial conditions as well as to deal with discrete time and non-smooth continuous time processes. We derive a closed form expression for the FPTD in z and Laplace-transform space to a boundary in one dimension. Two classes of problems are analysed in detail: discrete time symmetric random walks (Markovian) and continuous time Gaussian stationary processes (Markovian and non-Markovian). Our results are in good agreement with Langevin dynamics simulations.

  9. The selective angiographic diagnosis and endovascular embolization treatment of severe epistaxis

    International Nuclear Information System (INIS)

    Zhang Xiquan; Lu Yonghong; Sun Jinghua; Guo Deqiang; Li Yuzhen; Wei Aihua

    2002-01-01

    Objective: To evaluate selective angiographic diagnosis and embolization of severe epistaxis in 57 cases. Methods: 41 cases with spontaneous haemorrhage, 11 cases with traumatic haemorrhage, 3 cases with haemorrhage of nasopharyngeal fibroangioma, and 2 case with haemorrhage of nasopharyngeal carcinoma were included in the study. Selective angiographic diagnosis and embolization of epistaxis were performed with absorbable gelatin sponge or balloon or spring coil by using Seldinger's method. Results: 59 procedure of angiographic diagnosis and embolization were performed in 57 cases. Both maxillaris internal artery embolization was performed in 6 cases. After embolization, satisfactory results were achieved immediately in 55 cases. After 6 months to 2 years' follow-up, no haemorrhage recurred. In 4 cases with traumatic haemorrhage in the face, simple maxillaris internal artery embolization was performed in 2 cases. Conclusion: Selective angiographic diagnosis and embolization are safe, effective, and successful method of choices in the treatment of severe epistaxis

  10. Angiographic Findings and Embolotherapy in Renal Arterial Trauma

    International Nuclear Information System (INIS)

    Sofocleous, Constantinos T.; Hinrichs, Clay; Hubbi, Basil; Brountzos, Elias; Kaul, Sanjeev; Kannarkat, George; Bahramipour, Philip; Barone, Alison; Contractor, Daniel G.; Shah, Tanmaya

    2005-01-01

    Purpose To evaluate the angiographic findings and embolotherapy in the management of traumatic renal arterial injury Methods This is a retrospective review of 22 patients with renal trauma who underwent arteriography and percutaneous embolization from December 1995 to January 2002. Medical records, imaging studies and procedural reports were reviewed to assess the type of injury, arteriographic findings and immediate embolization results. Long-term clinical outcome was obtained by communication with the trauma physicians and by clinical chart review.Results Arteriography was performed in 125 patients admitted to a State Trauma Center with suspected internal bleeding. Renal arterial injury was documented in 22 and was the result of a motor-vehicle accident (10), auto-pedestrian accident (1), gunshot (4) or stab wounds (6) and a fall (1). Percutaneous renal arterial embolization was undertaken in 22 of 125 (18%) patients to treat extravasation (11), arterial pedicle rupture (5), abnormal arteriovenous (3) or arteriocalyceal (2) communication and pseudoaneurysm (3). One of the pseudoaneurysms and one of the arteriovenous fistulae were found in addition to extravasation. All 22 patients (16 men, 6 women) were hemodynamically stable, or controlled during arteriography and embolotherapy. Selective and/or superselective embolization of the abnormal vessels was performed using coils in 9 patients, microcoils in 9 patients and Gelfoam pledgets in 3 patients. In one patient Gelfoam pledgets mixed with polyvinyl alcohol (PVA) particles were used for embolization. Immediate angiographic evidence of hemostasis was demonstrated in all cases. Two initial technical failures were treated with repeat arteriography and embolization. There was no procedure-related death. There was no non-target embolization. One episode of renal abscess after embolization was treated by nephrectomy and 3 patients underwent elective post-embolization nephrectomy to prevent infection. Follow-up ranged

  11. The subtype of VSD and the angiographic differentiation

    International Nuclear Information System (INIS)

    Choe, Kyu Ok; Sul, Jun Hee; Lee, Sung Kyu; Cho, Bum Koo; Hong, Sung Nok

    1985-01-01

    VSD is the most common congenital cardiac malformation and the natural history depends not only on the age of patients and the size of defect but the subtype of VSD as well, important factor in clinical management of those patients. In 110 patients, with surgically repaired VSD in Yonsei Medical Center in 1984, the subtype of VSDs evaluated by surgical observation were correlated with LV angiogram findings to verify the incidence of subtype in Korean and the diagnostic accuracy to predict the subtype by angiogram. 1. 110 patients included 64 boys and 46 girls, the age ranged from 3 months to 14 years (average 4.6 years old). 2. Angiographic findings were interpreted as follows; a. Perimembranous defects were profiled in LAO 60 .deg. LV angiogram and located below the aortic valve. In inlet excavation the shunted blood opacified the recess between septal leaflet of tricuspid valve and interventricular septum in early phase, in infundibular excavation opacified the recess between anterior leaflet of TV and anterior free wall of RV and in trabecular excavation the shunted blood traversed anterior portion of TV ring, opacified trabecular portion of RV cavity. b. Subarterial types were profiled in RAO 30 .deg. LV angiogram, just below aortic valve as well as pulmonic valve. Total infundibular defects were profiled in RAO 30 .deg. and LAO 60 .deg. LV angiogram subaortic in location in both views. c. In muscular VSD the profiled angle was varied according to the subtype but the defects were separated from the aortic valve as muscular septum interposed between the aortic valve and the defect. 3. The incidence of subtype of VSDs evaluated by surgical observation were as follows. Subarterial type : 32 cases (29.1%) Total infundibular defect : 5 cases (4.5%) Perimembranous type : 73 cases (66.3%) Infundibular excavation : 32 cases (29.2%) Trabecular excavation : 28 cases (25.5%) Inlet excavation : 10 cases (9.1%) Mixed : 3 cases (2.7%) Muscular type : 1 cases (0.9%) Total 63

  12. Effect of transcatheter arterial embolization according to angiographic findings in hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Wang, Chi Hyung; Shim, Hyung Jin; Lee, Jong Ik; Yu, Hyun; Kim, Young Goo; Lee, Jong Beum; Kim, Kun Sang

    1994-01-01

    The purpose of this study is to assess the effect of Transcatheter Arterial Embolization(TAE) according to angiographic findings in hepatocellular carcinoma. We retrospectively reviewed 50 cases who received TAE for unresectable hepatocellular carcinoma. We analyzed the angiographic findings which were correlated with the effect of TAE. The common angiographic findings of the hepatocellular carcinoma were tumor staining, neo vascularity and enlargement of feeding artery. These angiographic findings were classified into grade 0, +1, +2. Effect of TAE were classified into five patterns; good response, partial response, minimal response, no response and more aggravation. In grading of tumor staining, among 50 cases, the grade 0, +1, +2 were seen in 1 case(2%), 14 cases(28%), 35 cases(70%) each. In grading of enlargement of feeding artery, the grade 0, +1, +2 were seen in 7 cases(14%), 19 cases(38%), 24 cases(48%) each. In grading of neo vascularity, the grade 0, +1, +2 were seen in 6 cases(12%), 15 cases(30%), 29 cases(58%) each. This study showed that the higher grade of angiographic finding, the better effect of TAE. A statistically significant difference was found (P<0.005). But the TAE was not effective in some cases (the maximum diameter of mass is over 10cm, portal vein thrombosis or arteriovenous shunt) in spite of high grade. We believe that these angiographic findings (tumor staining, enlargement of feeding artery, neo vascularity) are one of important indices for anticipating the effect of TAE in patients with unresectable hepatocellular carcinoma

  13. Evaluation of the angiographic findings in pulmonary atresia

    International Nuclear Information System (INIS)

    Choe, Kyu Ok; Sul, Jun Hee; Lee, Seung Kyu; Cho, Bum Koo; Hong, Pill Whoon

    1986-01-01

    We studied the angiographic findings in 65 patients with congenital pulmonary atresia, ages 4 days to 14 years (mean 3.3 yrs), from 1981 to 1986 at Severance Hospital Yonsei University. 1. 6 had pulmonary atresia with an intact interventricular septum, 38 had it with cardiac anomaly Renodynamically simulating TOF, and 21 associated with more complicated cardiac anomalies. 2. In the group with an intact ventricular septum, 5 showed confluent intrapericardial pulmonary artery, all segmental pulmonary arteries connected to intrapericardial artery. 3. In the group simulating TOF, aorta arose from RV with or without overriding in 35. In 27 patients with confluent intrapericardial pulmonary artery, 23 had more than 10 segmental pulmonary arteries connected to intrapericardial artery and 5 had severely hypoplastic hilar pulmonary arteries. In 11 with non confluent intrapericardial pulmonary artery, 4 had more than 10 segmental pulmonary arteries connected to central pulmonary artery and 9 had severely hypoplastic hilar pulmonary arteries. 4. In the group associated with more complicated cardiac anomaly, included 8 patients with atrioventricular discordance, 7 with univentricular heart and 6 with tricuspid atresia. In 17 patients with confluent intrapericardial artery, 16 had more than 10 segmental pulmonary arteries connected to intrapericardial artery, one showed severe hypoplasia of hilar pulmonary arteries. In another 4 with non confluence, no one showed more than 10 segmental arteries connected to intrapericardial or hilar pulmonary artery.

  14. Percutaneous vertebroplasty with a high-quality rotational angiographic unit

    Energy Technology Data Exchange (ETDEWEB)

    Pedicelli, Alessandro [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: apedicelli@rm.unicatt.it; Rollo, Massimo [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: mrollo@rm.unicatt.it; Piano, Mariangela [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: mariangela.piano@gmail.com; Re, Thomas J. [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: tomjre@gmail.com; Cipriani, Maria C. [Department of Gerontology, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: alexped@yahoo.com; Colosimo, Cesare [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: colosimo@rm.unicatt.it; Bonomo, Lorenzo [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: lbonomo@rm.unicatt.it

    2009-02-15

    We evaluated the reliability of a rotational angiographic unit (RA) with flat-panel detector as a single technique to guide percutaneous vertebroplasty (PVP) and for post-procedure assessment by 2D and 3D reformatted images. Fifty-five consecutive patients (104 vertebral bodies) were treated under RA fluoroscopy. Rotational acquisitions with 2D and 3D reconstruction were obtained in all patients for immediate post-procedure assessment. In complex cases, this technique was also used to evaluate the needle position during the procedure. All patients underwent CT scan after the procedure. RA and CT findings were compared. In all cases, a safe trans-pedicular access and an accurate control of the bone-cement injection were successfully performed with high-quality fluoroscopy, even at the thoracic levels and in case of vertebra plana. 2D and 3D rotational reconstructions permitted CT-like images that clearly showed needle position and were similar to CT findings in depicting intrasomatic implant-distribution. RA detected 40 cement leakages compared to 42 demonstrated by CT and showed overall 95% sensitivity and 100% specificity compared to CT for final post-procedure assessment. Our preliminary results suggest that high-quality RA is reliable and safe as a single technique for PVP guidance, control and post-procedure assessment. It permits fast and cost-effective procedures avoiding multi-modality imaging.

  15. Craniocervical artery dissection: MR imaging and MR angiographic findings

    International Nuclear Information System (INIS)

    Oelerich, M.; Schuierer, G.; Stoegbauer, F.; Kurlemann, G.; Schul, C.

    1999-01-01

    Dissection of the carotid and vertebral arteries is a not so uncommon cause of stroke and has to be considered as a differential diagnosis especially in younger patients. Therapeutic and prognostic implications are different from those in extracranial atherosclerotic disease. Dissection results from hemorrhage into the vessel wall usually between the layers of the media. Digital subtraction angiography (DSA) depicts the resulting luminal compromise that may reveal some typical, but not specific, findings. The same is true for non-invasive angiographic techniques such as time-of-flight magnetic resonance angiography (MRA) and computed tomography angiography (CTA), which have shown accurate results compared with DSA. The main advantage of these techniques is the direct visualization of the vessel wall confirming the intramural hematoma. This is achieved best with MR imaging due to the high signal of blood degradation products on T1- and T2-weighted images. Therefore, MRI in combination with MRA is presently the method of choice for initial diagnosis and follow-up of craniocervical artery dissection (CCAD). In some questionable cases, CTA is a non-invasive alternative that is independent of flow phenomena. (orig.)

  16. Craniocervical artery dissection: MR imaging and MR angiographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Oelerich, M.; Schuierer, G. [Institute of Clinical Radiology, University of Muenster (Germany); Stoegbauer, F. [Department of Neurology, University of Muenster (Germany); Kurlemann, G. [Department of Pediatric Neurology, University of Muenster (Germany); Schul, C. [Department of Neurosurgery, University of Muenster (Germany)

    1999-09-01

    Dissection of the carotid and vertebral arteries is a not so uncommon cause of stroke and has to be considered as a differential diagnosis especially in younger patients. Therapeutic and prognostic implications are different from those in extracranial atherosclerotic disease. Dissection results from hemorrhage into the vessel wall usually between the layers of the media. Digital subtraction angiography (DSA) depicts the resulting luminal compromise that may reveal some typical, but not specific, findings. The same is true for non-invasive angiographic techniques such as time-of-flight magnetic resonance angiography (MRA) and computed tomography angiography (CTA), which have shown accurate results compared with DSA. The main advantage of these techniques is the direct visualization of the vessel wall confirming the intramural hematoma. This is achieved best with MR imaging due to the high signal of blood degradation products on T1- and T2-weighted images. Therefore, MRI in combination with MRA is presently the method of choice for initial diagnosis and follow-up of craniocervical artery dissection (CCAD). In some questionable cases, CTA is a non-invasive alternative that is independent of flow phenomena. (orig.) With 6 figs., 2 tabs., 33 refs.

  17. The prevalence and clinical profile of angiographic coronary ectasia

    International Nuclear Information System (INIS)

    Sultana, R.; Ishaq, M.; Samad, A.

    2011-01-01

    To determine the incidence of Coronary Artery Ectasia (CAE) at our teaching hospital to describe the patients and angiographic characteristics. Methods: A retrospective analysis was conducted on all coronary angiograms performed at the catheterization laboratory of Karachi Institute of Heart Diseases, a tertiary care center, between the period of August 2006 and August 2008. A one year follow up was performed to look for primary and secondary endpoints. Data were collected from catheterization films, and medical records. Results: Five thousand coronary angiograms were performed during the period of of the study. A total of 140 (2.8%) angiograms showed coronary ectasia of both mixed and pure types. Pure ectasia with no coronary obstructive lesions was seen in 75 (1.5%). The left anterior descending artery (LAD) was the most commonly affected vessel (63%) followed by the right coronary artery (RCA) 25% and 10% patients had circumflex artery involvement. The primary composite endpoint showed 6 (4.2%) patients with non-ST elevation MI, 5 (3.6%) with ST elevation inferior wall myocardial infarction, 70 (50%) with unstable angina and 2 (1.4%) deaths due to pulmonary oedema. Secondary endpoints showed 50% of the patients still complaining of chest pain. Conclusion: Prevalence of Coronary ectasia in the population presenting to KIHD during the study period was 1.5%. Majority of patients were males, associated with dyslipidaemia, hypertension and smoking. CAE was associated with obstructive coronary artery disease in about 80% of cases. LAD was the most commonly affected vessel. (author)

  18. Pediatric renovascular hypertension in Thailand: CT angiographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Visrutaratna, Pannee; Srisuwan, Tanop; Sirivanichai, Chusak [Chiang Mai University, Department of Radiology, Faculty of Medicine, Chiang Mai (Thailand)

    2009-12-15

    Renovascular disease is an uncommon but important cause of hypertension in children. When unrecognized and untreated, renovascular hypertension in children can have serious complications. To review the causes of renovascular hypertension and computed tomography angiographic (CTA) findings in children and adolescents. Twenty-eight CTAs from January 2004 to March 2008 of 23 children and adolescents with hypertension were reviewed for the causes and CTA findings. Nine of the 23 children (39%) had abnormal renal arteries with or without abnormal abdominal aortas. Four of these children had Takayasu arteritis, one had moyamoya disease, and one had median arcuate ligament syndrome. One with chronic pyelonephritis had severe stenosis of the proximal right renal artery. The other two children had renal artery stenosis with a nonspecific cause. One child with a normal abdominal aorta and renal arteries had a right suprarenal mass. On pathological examination a ganglioneuroma was found. CTA can help in diagnosis of renovascular hypertension in children and adolescents. Although CTA is not a screening modality, it is appropriate in some situations. (orig.)

  19. Angiographic examinations of the circulatory development of living chick embryos

    International Nuclear Information System (INIS)

    Stoeter, P.; Buchhoecker, M.; Bruzek, W.; Drews, U.; Schulze, K.; Tuebingen Univ.; Tuebingen Univ.

    1980-01-01

    In chick embryos of an age of incubation of 5-14 days, the physiological development of the circulation and the morphological differentation of the arterical system were studied by intravital and postmortal angiography. For the examinations of the living embryos, a special radiographic and injection technique had to be developed. The contrast medium was injected into the umbilical veins and transported by the actions of the embryonic heart. Continuous ECG recordings showed no marked interference of the injections with the cardiac activity. According to the angiographic findings, the circulation is relatively fast within the main arteries, but the capillary perfusion is prolonged and lasts up to several minutes. The average circulatory velocity of the blood stream within the carotid artery increases parallel to the arterial enlargement, whereas the circulatory time decreases and the number of heart beats during the period of carotid opacification does not change to a great extent. By this, a steady transport of gas and nutritional material may be achieved in the growing arterial system. (orig.) [de

  20. Pediatric renovascular hypertension in Thailand: CT angiographic findings

    International Nuclear Information System (INIS)

    Visrutaratna, Pannee; Srisuwan, Tanop; Sirivanichai, Chusak

    2009-01-01

    Renovascular disease is an uncommon but important cause of hypertension in children. When unrecognized and untreated, renovascular hypertension in children can have serious complications. To review the causes of renovascular hypertension and computed tomography angiographic (CTA) findings in children and adolescents. Twenty-eight CTAs from January 2004 to March 2008 of 23 children and adolescents with hypertension were reviewed for the causes and CTA findings. Nine of the 23 children (39%) had abnormal renal arteries with or without abnormal abdominal aortas. Four of these children had Takayasu arteritis, one had moyamoya disease, and one had median arcuate ligament syndrome. One with chronic pyelonephritis had severe stenosis of the proximal right renal artery. The other two children had renal artery stenosis with a nonspecific cause. One child with a normal abdominal aorta and renal arteries had a right suprarenal mass. On pathological examination a ganglioneuroma was found. CTA can help in diagnosis of renovascular hypertension in children and adolescents. Although CTA is not a screening modality, it is appropriate in some situations. (orig.)

  1. The angiographic findings and interventional treatment of the iatrogenic hemobilia

    International Nuclear Information System (INIS)

    Wen feng; Lu Zaiming; Sun Wei; Li Wei; Guo Qiyong

    2012-01-01

    Objective: To evaluate the angiography and interventional embolization in diagnosing and treating the iatrogenic hemobilia. Methods: A total of 21 patients with iatrogenic hemobilia were enrolled in this study. The clinical data were retrospectively analyzed. Percutaneous selective superior mesenteric artery angiography, celiac angiography and common hepatic artery angiography were carried out in all patients. After the bleeding sites were clarified, selective or super-selective catheterization and embolization were performed. The clinical results were analyzed. Results: Active bleeding was confirmed by angiography in all the 21 cases. Angiographic findings included pseudoaneurysm (n=17, 81.0%) and extravasation of contrast medium (n=4, 19.0%). The embolic agents used in this study included polyvinyl alcohol particles (n=2), pure coils (n=8) or Gelfoam particles plus coils (n=11). The success rate of hemostasis after single embolization was 85.7% (18/21), and second embolization procedure had to be carried out in three patients as recurrent massive bleeding occurred in them. All the patients were followed up for 5 to 28 months, and no recurrent hemobilia was observed. No serious complications such as non-targeted vessel embolization, liver function failure, embolization-related infection, etc. occurred. Conclusion: For the treatment of iatrogenic hemobilia, percutaneous selective angiography together with interventional embolization is safe, minimally-invasive, reliable and effective, and this technique should be regarded as the treatment of first choice. (authors)

  2. Intractable epistaxis: which arteries are responsible? An angiographic study.

    Science.gov (United States)

    de Bonnecaze, Guillaume; Gallois, Y; Chaynes, P; Bonneville, F; Dupret-Bories, A; Chantalat, E; Serrano, E

    2017-11-01

    Epistaxis constitutes a significant proportion of the Otolaryngologist's emergency workload. Optimal management differs in relation to the anatomic origin of the bleeding. The outcome of our study was to determine which artery(ies) could be considered as the cause of severe bleeding in the context of severe epistaxis. Fifty-five procedures of embolization preceded by angiography were reviewed. Medical records of interventionally treated patients were analysed for demographics, medical history, risk factors and clinical data. Angiographic findings were also assessed for active contrast extravasation (blush), vascular abnormality and embolised artery. Previous angiography showed an active contrast extravasation in only 20 procedures. The most common bleeding source was the sphenopalatine artery (SPA) followed by anterior ethmoïdal artery (AEA) and facial artery. Majority of multiple or bilateral extravasations occured in patients with systemic factors. A better understanding of the potential bleeding source might help and limit the risk of treatment failures. Our study confirms that the SPA is the most common cause of severe bleeding. We also emphasise the role of the AEA not only in traumatic context. Others arteries are rarely involved except in patients with comorbidities or frequent recurrences.

  3. Comparative functional scintigraphic and angiographic examination in pancreas diseases

    International Nuclear Information System (INIS)

    Mendizov, A.; Brilski, V.; Bozhiyanov, A.; Romanova, A.; Mardzhanov, I.; Glavincheva, I.; Meditsinska Akademiya, Sofia

    1979-01-01

    Pancreas scintigraphy with 75 seleno-methionine, pancreocimine-secretine test and selective abdominal angiography was carried out in patients with chronic pancreatitis, pancreas carcinoma and subjects without any pancreas diseases. Scintigraphic changes in pancreas was found in 95,6 per cent of the patients with chronic pancreatitis (136 patients), in 92 per cent of them with pancreas carcinoma (25 patients) and in 53,4 per cent from the subjects without pancreas diseases (30 examined). Pathological changes in pancreatic secretion was found in 93,4 per cent of the patients with chronic pancreatitis (105 patients), in 93,8 per cent of the subjects with pancreas carcinoma (32 patients) and only in 3,9 per cent from the examined without pancreatic diseases. The angiographic examination is informative mainly in case of tumours and cysts of the pancreas. The diagnostic potentialities of the separate methods for pancreas examination were critically assessed. The basic diagnostic problems in pancreas diseases are solved to a great extent with the combined examination with scintigraphy pancreocimine test and angiography (76 patients). (author)

  4. Lagrangian Curves on Spectral Curves of Monopoles

    International Nuclear Information System (INIS)

    Guilfoyle, Brendan; Khalid, Madeeha; Ramon Mari, Jose J.

    2010-01-01

    We study Lagrangian points on smooth holomorphic curves in TP 1 equipped with a natural neutral Kaehler structure, and prove that they must form real curves. By virtue of the identification of TP 1 with the space LE 3 of oriented affine lines in Euclidean 3-space, these Lagrangian curves give rise to ruled surfaces in E 3 , which we prove have zero Gauss curvature. Each ruled surface is shown to be the tangent lines to a curve in E 3 , called the edge of regression of the ruled surface. We give an alternative characterization of these curves as the points in E 3 where the number of oriented lines in the complex curve Σ that pass through the point is less than the degree of Σ. We then apply these results to the spectral curves of certain monopoles and construct the ruled surfaces and edges of regression generated by the Lagrangian curves.

  5. Angiographic classification of patent ductus arteriosus and its clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    Qingqiao, Zhang; Shiliang, Jiang; Lianjun, Huang; Shihua, Zhao; Jian, Ling; Zhongying, Xu; Hong, Zheng; Ruolan, Xie; Ruping, Dai [Chinese Academy of Medical Sciences and Beijing Union Medical College, Beijing (China). Cardiovascular Inst. and Fuwai Hospital, Dept. of Radiology

    2004-04-01

    Objective: To study the angiographic appearance of patent ductus arteriosus (PDA) and provide information for clinical treatment. Methods: Between July 1994 and October 2002, 483 patients (142 male, 341 female) with isolated PDA underwent aortography before attempted transcatheter closure of PDA, the mean age was (14.6 {+-} 11.4) years (range 0.8 to 63 years). Left lateral aortography was performed in 482 patients. Among them, additional aortography in right anterior oblique 30 degree - 50 degree or left anterior oblique 60 degree - 80 degree (or plus caudal 20 degree) projection was performed in 6 and 4 patients, respectively. One patient with mirror-image dextrocardia underwent aortography in right lateral projection. Results: The configuration of PDA was classified into six types. Four hundred and twenty (87%) patients had funnel shape PDA, the mean minimum diameter of PDA was 4.2 {+-} 1.6 mm (range 1 to 15 mm). Three (0.6%) patients had window shape PDA, the diameters of PDA were 8.0 mm, 9.0 mm, and 9.0 mm, respectively. Thirty four (7.0%) patients had tubular shape PDA, the mean diameter of PDA was (5.4 {+-} 3.8) mm (range 0.8 to 20 mm). Eleven (2.3%) patients had rosary shape PDA, the mean minimum diameter of PDA was (2.1 {+-} 0.5) mm (range 1.0 to 3.7 mm). Ten (2.1%) patients had finger shape PDA, the mean minimum diameter of PDA was (1.5 {+-} 0.4) mm (range 1.0 to 3.0 mm). Five (1.0%) patients had irregular shape PDA, the minimum diameters of PDA were 1.2, 2.1, 3.2, 4.0, and 6.0 mm, respectively. Conclusion: The morphology of PDA varied considerably, and the awareness of these variations is helpful for clinical treatment.

  6. Angiographic classification of patent ductus arteriosus and its clinical implications

    International Nuclear Information System (INIS)

    Zhang Qingqiao; Jiang Shiliang; Huang Lianjun; Zhao Shihua; Ling Jian; Xu Zhongying; Zheng Hong; Xie Ruolan; Dai Ruping

    2004-01-01

    Objective: To study the angiographic appearance of patent ductus arteriosus (PDA) and provide information for clinical treatment. Methods: Between July 1994 and October 2002, 483 patients (142 male, 341 female) with isolated PDA underwent aortography before attempted transcatheter closure of PDA, the mean age was (14.6 ± 11.4) years (range 0.8 to 63 years). Left lateral aortography was performed in 482 patients. Among them, additional aortography in right anterior oblique 30 degree - 50 degree or left anterior oblique 60 degree - 80 degree (or plus caudal 20 degree) projection was performed in 6 and 4 patients, respectively. One patient with mirror-image dextrocardia underwent aortography in right lateral projection. Results: The configuration of PDA was classified into six types. Four hundred and twenty (87%) patients had funnel shape PDA, the mean minimum diameter of PDA was 4.2 ± 1.6 mm (range 1 to 15 mm). Three (0.6%) patients had window shape PDA, the diameters of PDA were 8.0 mm, 9.0 mm, and 9.0 mm, respectively. Thirty four (7.0%) patients had tubular shape PDA, the mean diameter of PDA was (5.4 ± 3.8) mm (range 0.8 to 20 mm). Eleven (2.3%) patients had rosary shape PDA, the mean minimum diameter of PDA was (2.1 ± 0.5) mm (range 1.0 to 3.7 mm). Ten (2.1%) patients had finger shape PDA, the mean minimum diameter of PDA was (1.5 ± 0.4) mm (range 1.0 to 3.0 mm). Five (1.0%) patients had irregular shape PDA, the minimum diameters of PDA were 1.2, 2.1, 3.2, 4.0, and 6.0 mm, respectively. Conclusion: The morphology of PDA varied considerably, and the awareness of these variations is helpful for clinical treatment

  7. Transarterial embolization in the management of intractable epistaxis: the angiographic findings and results based on etiologies.

    Science.gov (United States)

    Wang, Bin; Zu, Qing-Quan; Liu, Xing-Long; Zhou, Chun-Gao; Xia, Jin-Guo; Zhao, Lin-Bo; Shi, Hai-Bin; Liu, Sheng

    2016-08-01

    Transarterial embolization (TAE) appears to be a safe and effective treatment for patients with intractable epistaxis, despite different etiologies or angiography findings. Idiopathic epistaxis is prone to present with negative angiographic findings. To retrospectively evaluate the safety and effectiveness of TAE for intractable epistaxis, and focus on the factors of etiology and angiographic findings. From March 2008 to December 2014, the data of 43 patients with intractable bleeding undergoing TAE were reviewed. The outcomes of interventional therapy were assessed according to different etiology (malignant or benign disease) and angiographic finding (positive or negative angiogram). Positive angiographic findings were found in 11 of 12 cases with malignant diseases and 22 of 31 cases with benign diseases, respectively (p = 0.237). Among the 10 cases with negative angiographic findings, the negative angiography rate of idiopathic epistaxis was higher than that of epistaxis with definite etiology (p = 0.003). Bleeding was controlled successfully in all of the 43 patients after embolization. During the mean follow-up period of 24.0 ± 16.7 months, five patients relapsed. No significant difference was found in recurrence rates between malignant and benign diseases or between positive and negative angiography (p = 0.241, p = 0.704, respectively).

  8. Shock Index Correlates with Extravasation on Angiographs of Gastrointestinal Hemorrhage: A Logistics Regression Analysis

    International Nuclear Information System (INIS)

    Nakasone, Yutaka; Ikeda, Osamu; Yamashita, Yasuyuki; Kudoh, Kouichi; Shigematsu, Yoshinori; Harada, Kazunori

    2007-01-01

    We applied multivariate analysis to the clinical findings in patients with acute gastrointestinal (GI) hemorrhage and compared the relationship between these findings and angiographic evidence of extravasation. Our study population consisted of 46 patients with acute GI bleeding. They were divided into two groups. In group 1 we retrospectively analyzed 41 angiograms obtained in 29 patients (age range, 25-91 years; average, 71 years). Their clinical findings including the shock index (SI), diastolic blood pressure, hemoglobin, platelet counts, and age, which were quantitatively analyzed. In group 2, consisting of 17 patients (age range, 21-78 years; average, 60 years), we prospectively applied statistical analysis by a logistics regression model to their clinical findings and then assessed 21 angiograms obtained in these patients to determine whether our model was useful for predicting the presence of angiographic evidence of extravasation. On 18 of 41 (43.9%) angiograms in group 1 there was evidence of extravasation; in 3 patients it was demonstrated only by selective angiography. Factors significantly associated with angiographic visualization of extravasation were the SI and patient age. For differentiation between cases with and cases without angiographic evidence of extravasation, the maximum cutoff point was between 0.51 and 0.0.53. Of the 21 angiograms obtained in group 2, 13 (61.9%) showed evidence of extravasation; in 1 patient it was demonstrated only on selective angiograms. We found that in 90% of the cases, the prospective application of our model correctly predicted the angiographically confirmed presence or absence of extravasation. We conclude that in patients with GI hemorrhage, angiographic visualization of extravasation is associated with the pre-embolization SI. Patients with a high SI value should undergo study to facilitate optimal treatment planning

  9. CT and angiographic appearances of hepatocellular carcinoma partially fed by right inferior phrenic artery

    Energy Technology Data Exchange (ETDEWEB)

    Ohtomo, Kuni; Furui, Shigeru; Yoshikawa, Hiroki; Yashiro, Naofumi; Araki, Tsutomu [Tokyo Univ. (Japan). Faculty of Medicine

    1983-04-01

    CT and angiographic appearances of 8 hepatocellular carcinomas which were partially fed by right inferior phrenic artery were discussed. CT demonstrated tumor fully occupied posterior segment of right hepatic lobe in 6 cases which were composed of 3 solitary massive, 2 massive nodular and 1 confluent massive angiographically. In the other 2 cases, CT showed encapsulated tumor in posterior inferior portion of posterior segment protruded from the liver. In 6 out of these 8 cases, tumor vessels and tumor stain were chiefly derived from posterior branch of right inferior phrenic artery.

  10. Cerebral angiographic changes on serial examination of a patient with migraine

    Energy Technology Data Exchange (ETDEWEB)

    Masuzawa, T.; Shinoda, S.; Nakahara, N.; Abe, F.; Sato, F.; Furuse, M.

    1983-03-01

    Curious cerebral angiographic changes are described in a 27-year-old female migraine patient. During the period of observation of this patient, both the intracranial carotid artery and the vertebrobasilar artery systems presented unusual and fascinating cerebral arteriographic pictures. In an attack of migraine, angiography showed that all the intracranial secondary and tertiary branches of the carotid arterial system were dilated without showing any changes in the extracranial arteries and when the migraine attack had subsided, all branches of the carotid arteries as well as the vertebrobasilar arteries demonstreated abnormal segmental narrowings or vasospasm. These sequential angiographic changes have not been hitherto reported in migraine.

  11. Angiographic study of digital arteries in workers exposed to vinyl chloride

    Energy Technology Data Exchange (ETDEWEB)

    Falappa, P; Magnavita, N; Bergamaschi, A; Colavita, N

    1982-05-01

    Five patients exposed to vinyl chloride were studied by hand angiography and other non-invasive methods, including photoplethysmography, rheography, and thermography. Raynaud's phenomenon was present in all five subjects, while acro-osteolysis affected only one. Organic vascular lesions, such as narrowing, segmentary occlusions of digital arteries and bridge collaterals, were found in angiographic studies. Only one patient did not show clear segmentary occlusions, but his vessels were crooked and diffusely narrowed. Angiographic results appear to correlate well with the changes shown by non-invasive techniques.

  12. CT and angiographic appearances of hepatocellular carcinoma partially feeded by right inferior phrenic artery

    International Nuclear Information System (INIS)

    Ohtomo, Kuni; Furui, Shigeru; Yoshikawa, Hiroki; Yashiro, Naofumi; Araki, Tsutomu

    1983-01-01

    CT and angiographic appearances of 8 hepatocellular carcinomas which were partially feeded by right inferior phrenic artery were discussed. CT demonstrated tumor fully occupied posterior segment of right hepatic lobe in 6 cases which were composed of 3 solitary massive, 2 massive nodular and 1 confluent massive angiographically. In the other 2 cases, CT showed encapsulated tumor in posterior inferior portion of posterior segment protruded from the liver. In 6 out of these 8 cases, tumor vessels and tumor stain were chiefly derived from posterior branch of right inferior phrenic artery. (author)

  13. The pharmaco-kinetics of angiographic contrast media with special reference to the extravascular spaces. Fundamental studies on dogs for the characterization of angiographic media. Pt. 1

    International Nuclear Information System (INIS)

    Lagemann, K.

    1975-01-01

    The pharmaco-kinetics of angiographic contrast media in the extra-vascular space, which are largely unknown, were investigated experimentally in dogs. As part of a basic study, using radio-active contrast media, it was possible to determine the concentration and rate of elimination in practically all organs and tissues. Measurements were carried out first after prolonged infusion of contrast under conditions of balanced flow, and secondly six hours after the end of the infusion. It was therefore possible to determine the inflow and loss of contrast medium in various organs, or organs systems. The most commonly used angiographic contrast media in Germany were investigated. Their kinetic behaviour is largely identical, their pattern of distribution and elimination depended principally on the organ or tissue. (orig.) [de

  14. Clinical and angiographic predictors of haemodynamically significant angiographic lesions: development and validation of a risk score to predict positive fractional flow reserve.

    Science.gov (United States)

    Sareen, Nishtha; Baber, Usman; Kezbor, Safwan; Sayseng, Sonny; Aquino, Melissa; Mehran, Roxana; Sweeny, Joseph; Barman, Nitin; Kini, Annapoorna; Sharma, Samin K

    2017-04-07

    Coronary revascularisation based upon physiological evaluation of lesions improves clinical outcomes. Angiographic or visual stenosis assessment alone is insufficient in predicting haemodynamic stenosis severity by fractional flow reserve (FFR) and therefore cannot be used to guide revascularisation, particularly in the lesion subset system formulated. Of 1,023 consecutive lesions (883 patients), 314 (31%) were haemodynamically significant. Characteristics associated with FFR ≤0.8 include male gender, higher SYNTAX score, lesions ≥20 mm, stenosis >50%, bifurcation, calcification, absence of tortuosity and smaller reference diameter. A user-friendly integer score was developed with the five variables demonstrating the strongest association. On prospective validation (in 279 distinct lesions), the increasing value of the score correlated well with increasing haemodynamic significance (C-statistic 0.85). We identified several clinical and angiographic characteristics and formulated a scoring system to guide the approach to intermediate lesions. This may translate into cost savings. Larger studies with prospective validation are required to confirm our results.

  15. ECM using Edwards curves

    DEFF Research Database (Denmark)

    Bernstein, Daniel J.; Birkner, Peter; Lange, Tanja

    2013-01-01

    -arithmetic level are as follows: (1) use Edwards curves instead of Montgomery curves; (2) use extended Edwards coordinates; (3) use signed-sliding-window addition-subtraction chains; (4) batch primes to increase the window size; (5) choose curves with small parameters and base points; (6) choose curves with large...

  16. Cognitive deficits after aneurysmal and angiographically negative subarachnoid hemorrhage : Memory, attention, executive functioning, and emotion recognition

    NARCIS (Netherlands)

    Buunk, Anne M; Groen, Rob J M; Veenstra, Wencke S; Metzemaekers, Joannes; van der Hoeven, Johannes H; van Dijk, J Marc C; Spikman, Jacoba M

    2016-01-01

    OBJECTIVE: The authors' aim was to investigate cognitive outcome in patients with aneurysmal and angiographically negative subarachnoid hemorrhage (aSAH and anSAH), by comparing them to healthy controls and to each other. Besides investigating cognitive functions as memory and attention, they

  17. Comparative quantitative angiographic analysis of directional coronary atherectomy and balloon coronary angioplasty

    NARCIS (Netherlands)

    V.A.W.M. Umans (Victor); K.J. Beatt (Kevin); B.J.W.M. Rensing (Benno); W.R.M. Hermans (Walter); P.J. de Feyter (Pim); P.W.J.C. Serruys (Patrick)

    1991-01-01

    markdownabstract__Abstract__ An attempt to assess the “utility” of directional atherectomy was made using a new quantitative angiographic index. This index can be subdivided into an initial gain component and a restenosis component. The initial gain index is the ratio between the gain in diameter

  18. Should incidental asymptomatic angiographic stenoses and occlusions be treated in patients with peripheral arterial disease?

    LENUS (Irish Health Repository)

    Keeling, Aoife N

    2009-09-01

    The clinical importance of angiographically detected asymptomatic lower-limb stenoses and occlusions is unknown. This study aims to (i) assess the clinical outcome of asymptomatic lesions in the lower limb, (ii) identify predictors of clinical deterioration, and (iii) determine which asymptomatic lower-limb lesions should be treated at presentation.

  19. Economic evaluation of angiographic interventions including a whole-radiology in- and outpatient care

    International Nuclear Information System (INIS)

    Nolte-Ernsting, C.; Abel, K.; Krupski, G.; Lorenzen, J.; Adam, G.

    2006-01-01

    Purpose: To determine the economic efficiency of a whole-radiology in- and outpatient treatment with angiographic interventions performed as the main or sole therapy. Materials and Methods: The calculations represent the data of a university radiology department, including the following angiographic interventions (neuroradiology not considered): Vascular intervention (PTA, stent implantation) of kidneys and extremities, recanalization of hemodialysis access, chemoembolization, diagnostic arterioportal liver CT, port implantation, varicocele embolization, PTCD, percutaneous implantation of biliary stent. First, the different angiographic interventions are categorized with reference to the German DRG system 2005. Considering the example of a university hospital, the individual cost of each intervention is calculated and correlated with reimbursements by G-DRG2005 and so-called ''ambulant operation'' (EBM200plus). With these data, profits and losses are calculated for both in- and outpatient care. Results: Radiologic interventions of inpatients yield a profit in the majority of cases. With a base rate of 2900 Euro, the profits in our university hospital range between -872 Euro and +3411 Euro (mean: +1348 Euro). On the other hand, those angiographic interventions suitable for ''ambulant operation'' generate average profits of +372 Euro, if only direct costs are considered. The data of outpatient radiological interventions average between 381 Euro up to 1612 Euro lower than compared with profits obtained from in patient care. (orig.)

  20. Risk factors and short-term outcome in patients with angiographically negative subarachnoid hemorrhage

    DEFF Research Database (Denmark)

    Dalbjerg, Sara Maria; Larsen, Carl Christian; Romner, Bertil

    2013-01-01

    The objective of this study was to identify prognostic factors for clinical outcome in patients with non-traumatic, angiographically negative subarachnoid hemorrhage. Furthermore, the aim was to investigate if patients on anticoagulant therapy may have a more unfavorable outcome than patients...

  1. Contractibility of curves

    Directory of Open Access Journals (Sweden)

    Janusz Charatonik

    1991-11-01

    Full Text Available Results concerning contractibility of curves (equivalently: of dendroids are collected and discussed in the paper. Interrelations tetween various conditions which are either sufficient or necessary for a curve to be contractible are studied.

  2. Effect of glycoprotein IIb/IIIa receptor inhibition on angiographic complications during percutaneous coronary intervention in the ESPRIT trial.

    Science.gov (United States)

    Blankenship, J C; Tasissa, G; O'Shea, J C; Iliadis, E A; Bachour, F A; Cohen, D J; Lui, H K; Mann, T; Cohen, E; Tcheng, J E

    2001-09-01

    We sought to determine whether eptifibatide decreases the incidence of in-laboratory angiographic complications and to determine the relationship of angiographically evident complications to elevations of creatine kinase-MB (CK-MB) enzyme levels during percutaneous coronary intervention. In the Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial, eptifibatide during coronary intervention was associated with decreased ischemic complications at 48 h and 30 days. Patients (n = 2,064) were randomized to placebo versus eptifibatide (two 180 microg/kg boluses 10 min apart and as a continuous infusion of 2 microg/kg per min) during percutaneous coronary stenting. Angiographic complications including major dissection, distal embolization, residual thrombus, abrupt closure, residual stenosis >50% and side-branch occlusion were prospectively recorded by the operator. Creatine kinase-MB levels were measured after the procedure and every 6 h thereafter. The incidence of angiographic complications and CK-MB elevation was determined for eptifibatide versus placebo groups. Eptifibatide-treated patients demonstrated nonsignificant trends toward fewer angiographic complications (10 vs. 12% for placebo patients, p = 0.13) and, for patients with angiographic complications, fewer subsequent CK-MB elevations (43 vs. 50% for placebo patients, p = 0.31). In patients without any angiographic complications, the incidence of CK-MB elevation >3 times the normal was 7% with placebo and 4% with eptifibatide (p = 0.003). Eptifibatide during nonurgent coronary stent intervention only minimally (and insignificantly) reduces the incidence of angiographic complications and subsequent CK-MB elevations in patients developing an angiographic complication. The greater effect is to reduce myocardial infarction in patients undergoing otherwise uneventful coronary stent implantation as well as in the overall study population.

  3. A spontaneous pre-anastomotic occlusion does not necessarily impair forearm native dialysis fistulas: echo-Doppler, 3D MR angiographic and digital subtraction angiographic imaging.

    Science.gov (United States)

    Verbeeck, N; Pillet, J C; Prospert, E; McLntyre, D; Lamy, S

    2013-01-01

    Renal transplantation is the choice treatment of end-stage renal disease. When it is not indicated or not immediately feasible, hemodialysis must be performed, preferably via a native arteriovenous fistula in the forearm. A pre-anastomotic occlusion of this type of fistula is often accompanied by a thrombosis of its draining vein. In some instances, the venous segment may remain permeable thanks to the development of arterial collateral pathways and may even allow efficient dialysis without any clinical syndrome of distal steal. We present the echo-Doppler, magnetic and angiographic characteristics of three of these collateralized shunts that have remained functional, in one of the cases following a percutaneous dilation.

  4. Correlation Between Contrast Time-Density Time on Digital Subtraction Angiography and Flow: An in Vitro Study.

    Science.gov (United States)

    Brunozzi, Denise; Shakur, Sophia F; Ismail, Rahim; Linninger, Andreas; Hsu, Chih-Yang; Charbel, Fady T; Alaraj, Ali

    2018-02-01

    Digital subtraction angiography (DSA) provides an excellent anatomic characterization of cerebral vasculature, but hemodynamic assessment is often qualitative and subjective. Various clinical algorithms have been produced to semiquantify flow from the data obtained from DSA, but few have tested them against reliable flow values. An arched flow model was created and injected with contrast material. Seventeen injections were acquired in anterior-posterior and lateral DSA projections, and 4 injections were acquired in oblique projection. Image intensity change over the angiogram cycle of each DSA run was analyzed through a custom MATLAB code. Time-density plots obtained were divided into 3 components (time-density times, TDTs): TDT 10%-100% (time needed for contrast material to change image intensity from 10% to 100%), TDT 100%-10% (time needed for contrast material to change image intensity from 100% to 10%), and TDT 25%-25% (time needed for contrast material to change from 25% image intensity to 25%). Time-density index (TDI) was defined as model cross-sectional area to TDT ratio, and it was measured against different flow rates. TDI 10%-100% , TDI 100%-10% , and TDI 25%-25% all correlated significantly with flow (P < 0.001). TDI 10%-100% , TDI 100%-10% , and TDI 25%-25% showed, respectively, a correlation coefficient of 0.91, 0.91, and 0.97 in the anterior-posterior DSA projections (P < 0.001). In the lateral DSA projection, TDI 100%-10% showed a weaker correlation (r = 0.57; P = 0.03). Also in the oblique DSA projection, TDIs correlated significantly with flow. TDI on DSA correlates significantly with flow. Although in vitro studies might overlook conditions that occur in patients, this method appears to correlate with the flow and could offer a semiquantitative method to evaluate the cerebral blood flow. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Comparison of intravascular ultrasound and angiographic assessement of coronary reference segment size in patients with type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Mintz, Gary S

    2008-01-01

    During percutaneous coronary intervention, the reference segment is assessed angiographically. This report described the discrepancy between angiographic and intravascular ultrasound (IVUS) assessment of reference segment size in patients with type 2 diabetes mellitus. Preintervention IVUS was used...... to study 62 de novo lesions in 41 patients with type 2 diabetes mellitus. The lesion site was the image slice with the smallest lumen cross-sectional area (CSA). The proximal and distal reference segments were the most normal-looking segments within 5 mm proximal and distal to the lesion. Plaque burden...... was measured as plaque CSA/external elastic membrane (EEM) CSA. Using IVUS, the reference lumen diameter was 2.80 +/- 0.42 mm and the reference EEM diameter was 4.17 +/- 0.56 mm. The angiographic reference diameter was 2.63 +/- 0.36 mm. Mean difference between the IVUS EEM diameter and angiographic reference...

  6. Hemodynamic disturbances in cerebral ischemia; Correlation between positron emission tomographic and angiographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Tenjin, Hiroshi; Ueda, Satoshi; Mizukawa, Norihiko; Imahori, Yoshio; Hino, Akihiko; Ohmori, Yoshio [Kyoto Prefectural Univ. of Medicine (Japan); Nakahashi, Hisamitsu

    1993-04-01

    Proper treatment of ischemic stroke requires better understanding of cerebral hemodynamic changes. The hemodynamic changes associated with ischemia were measured using positron emission tomography and related to angiographic findings in the subacute and chronic stages of 17 ischemia patients who showed symptoms of main trunk stenosis of the internal carotid artery system. The hemodynamic factors, cerebral blood flow, cerebral blood volume, cerebral metabolic rate for oxygen, oxygen extraction fraction, and flow/volume ratio, were measured in regions of interest determined from the angiographic stenosis (over 50%) and compared in each stage. The cerebral blood flow and flow/volume ratio in the territory downstream of the main trunk stenosis and cerebral metabolic rate for oxygen in the whole cortex were decreased in the subacute stage. In the chronic stage, cerebral blood flow and flow/volume ratio decreased mainly in borderzone areas. (author).

  7. Clinical results of stereotactic heavy-charged-particle radiosurgery for intracranial angiographically occult vascular malformations

    International Nuclear Information System (INIS)

    Levy, R.P.; Fabrikant, J.I.; Phillips, M.H.; Frankel, K.A.; Steinberg, G.K.; Marks, M.P.; DeLaPaz, R.L.; Chuang, F.Y.S.; Lyman, J.T.

    1989-12-01

    Angiographically occult vascular malformations (AOVMs) of the brain have been recognized for many years to cause neurologic morbidity and mortality. They generally become symptomatic due to intracranial hemorrhage, focal mass effect, seizures or headaches. The true incidence of AOVMs is unknown, but autopsy studies suggest that they are more common than high-flow angiographically demonstrable arteriovenous malformations (AVMs). We have developed stereotactic heavy-charged-particle Bragg peak radiosurgery for the treatment of inoperable intracranial vascular malformations, using the helium ion beams at the Lawrence Berkeley Laboratory 184-inch Synchrocyclotron and Bevatron. This report describes the protocol for patient selection, radiosurgical treatment planning method, clinical and neuroradiologic results and complications encountered, and discusses the strengths and limitations of the method. 10 refs., 1 fig

  8. Clinical results of stereotactic heavy-charged-particle radiosurgery for intracranial angiographically occult vascular malformations

    Energy Technology Data Exchange (ETDEWEB)

    Levy, R.P.; Fabrikant, J.I.; Phillips, M.H.; Frankel, K.A.; Steinberg, G.K.; Marks, M.P.; DeLaPaz, R.L.; Chuang, F.Y.S.; Lyman, J.T.

    1989-12-01

    Angiographically occult vascular malformations (AOVMs) of the brain have been recognized for many years to cause neurologic morbidity and mortality. They generally become symptomatic due to intracranial hemorrhage, focal mass effect, seizures or headaches. The true incidence of AOVMs is unknown, but autopsy studies suggest that they are more common than high-flow angiographically demonstrable arteriovenous malformations (AVMs). We have developed stereotactic heavy-charged-particle Bragg peak radiosurgery for the treatment of inoperable intracranial vascular malformations, using the helium ion beams at the Lawrence Berkeley Laboratory 184-inch Synchrocyclotron and Bevatron. This report describes the protocol for patient selection, radiosurgical treatment planning method, clinical and neuroradiologic results and complications encountered, and discusses the strengths and limitations of the method. 10 refs., 1 fig.

  9. MR imaging assessment of cerebral vascular disease: A combination of angiographic and parenchymal techniques

    International Nuclear Information System (INIS)

    Masaryk, T.J.; Modic, M.T.; Ross, J.S.; Ruggieri, P.; Laub, G.; Haacke, E.M.

    1988-01-01

    This study tested the accuracy and clinical utility of a three-dimensional MR angiographic technique of the cervical carotids in combination with a routine spin-echo examination of the brain as a screening examination for cerebrovascular disease in 23 patients. The technique used a fast low-angle shot sequence with a reduced echo time and voxel size, gradient refocusing, and time of flight effects to minimize signal loss secondary to phase dispersion and maximize vessel contrast. Subsequent multiplanar three-dimensional reconstructions were obtained at 5 0 increments about the z-axis via ray-tracing linear thresholding algorithms. Examinations were compared with IV/IA-digital subtraction angiography or Doppler US as the objective of accuracy. Results of this ongoing study indicate that an MR angiographic screening examination can be coupled with routine brain MR imaging with only a 10-14 minute extension of examination time, providing both a vascular and a parenchymal evaluation

  10. MR angiographic and parenchymal evaluation of cerebral infaraction in sickle cell anemia

    International Nuclear Information System (INIS)

    Masaryk, T.J.; Masaryk, A.M.; Ross, J.S.; Modic, M.T.; Wiznitzer, M.; Berman, B.

    1989-01-01

    Cerebral infarction is an important complication of sickle cell anemia, believed to be related to large-vessel stenoses/occlusion and/or capillary/venous sickling resulting in thrombosis. Identification of these complications (especially large-vessel arterial disease) is important in selecting patients for transfusion therapy. The purpose of this study was to determine the suitability of combined three-dimensional Fourier transform time-of-flight MR angiographic and parenchymal T2-weighted spin-echo examinations for evaluation of central nervous system (CNS) complications of sickle cell anemia. Seven patients (age range, 5-14 years) were evaluated. Five had documented strokes while two had symptoms resembling those of transient ischemic attack. The preliminary data indicate that combined MR angiographic and parenchymal studies are capable of identifying those patients with sickle cell anemia complicated by large-vessel CNS occlusive disease and cerebral infarction and can be used as a noninvasive guide to therapy

  11. Comparison of equilibrium radionuclide and contrast angiographic measurements of left ventricular peak ejection and filling rates and their time intervals

    Energy Technology Data Exchange (ETDEWEB)

    Sugrue, D.D.; Dickie, S.; Newman, H.; Myers, M.J.; Lavender, J.P.; McKenna, W.J. (Royal Postgraduate Medical School, London (UK))

    1984-10-01

    A comparison has been made of the equilibrium radionuclide and contrast angiographic estimates of normalized peak rates of ejection (PER) and filling (PFR) and their time intervals in twenty-one patients with cardiac disorders. Contrast angiographic and radionuclide measurements of left ventricular ejection fraction (LVEF), PER and PFR correlated well but time intervals correlated poorly. Mean values for radionuclide LVEF, PER and PFR were significantly lower and radionuclide time intervals were significantly longer compared to contrast angiography measurements.

  12. The pretzel sign: angiographic pattern of tortuous intra-aneurysmal blood flow in a giant serpentine aneurysm.

    LENUS (Irish Health Repository)

    Fanning, N F

    2012-02-03

    Giant serpentine aneurysms (GSAs) form a specific subgroup of giant cerebral aneurysms that have pathognomonic angiographic features. We report the angiographic findings of a GSA demonstrating a striking convoluted dynamic flow pattern, which we have called the \\'pretzel sign\\'. The aneurysm was successfully treated by permanent occlusion of the parent vessel using a detachable balloon. GSAs should be identified prior to treatment in view of their particular management requirements.

  13. Angiographic differentiation of the forms of truncus arteriosis communis and their prognostic significance

    International Nuclear Information System (INIS)

    Schumacher, G.; Schreiber, R.; Lorenz, H.P.; Sebening, W.; Meisner, H.; Sebening, F.; Buehlmeyer, K.; Deutsches Herzzentrum Muenchen des Freistaates Bayern

    1986-01-01

    To decisively improve the life expectancy of children having a truncus arteriosus communis, early surgical intervention during the first year is necessary. As a prerequisite for a successful intervention, a precise diagnosis must be made including angiographic differentiation of the form of the truncus arteriosus communis and possible associated cardiovascular malformations must be established; these constitute important operation hazards and can determine the ultimate success of the intervention. (orig.) [de

  14. Cerebral Angiographic Findings of Cosmetic Facial Filler-related Ophthalmic and Retinal Artery Occlusion

    OpenAIRE

    Kim, Yong-Kyu; Jung, Cheolkyu; Woo, Se Joon; Park, Kyu Hyung

    2015-01-01

    Cosmetic facial filler-related ophthalmic artery occlusion is rare but is a devastating complication, while the exact pathophysiology is still elusive. Cerebral angiography provides more detailed information on blood flow of ophthalmic artery as well as surrounding orbital area which cannot be covered by fundus fluorescein angiography. This study aimed to evaluate cerebral angiographic features of cosmetic facial filler-related ophthalmic artery occlusion patients. We retrospectively reviewed...

  15. Coronary arterial Disease associated with arteriosclerosis in lower extremity: Angiographic analysis

    International Nuclear Information System (INIS)

    Kim, Ji Hye; Chung, Jin Wook; Lee, Seon Kyu; Han, Joon Koo; Park, Jae Hyung; Kim, Jae Seung; Han, Man Chung

    1993-01-01

    We performed both peripheral and coronary angiographies in 52 patients with an arteriosclerosis in lower extremities. The severity of arteriosclerotic narrowing of the coronary and peripheral arteries were compared on angiographies. An angiographic vascular score(AVS, 0-5) reflecting the number and the degree of stenosis in 12 lower extremity arteries and three major coronary arteries was assigned to each angiogram and the sun of scores in the lower extremity arteries was compared with the incidence of significant coronary artery disease (more than grade 3) and coronary score. Relation of incidence and severity of vascular stenosis and risk factors (diabetes metallitus, hypertension, smoking, and hypercholesterolemia) was also analyzed. Thirty-four of 52 patients (65%) had an angiographically significant coronary artery disease. Thirteen of these 34 patients (38%) had no clinical symptom and sign of the ischemic heart disease. There was no statistically significant difference in the incidence and severity of coronary artery disease between high (more than 30) and low AVS group in lower extremity (p>0.14). All patients had at least one risk factor and 49 of 52 patients (94%) had multiple risk factors. Coronary angiography was normal in there patients with only one risk factors, and angiographically significant coronary artery disease existed in nine of 16 cases (56.3%) with two risk factors. 13 of 17 case (76.5%) with three risk factors, and 12 of 16 cases (75.0%) with all four risk factors. There were no significant correlations between individual risk factors and incidence, severity of arteriosclerosis in coronary and lower extremity arteries. In conclusion, angiographic evaluation of the coronary artery disease in patients with lower extremity arteriosclerosis is necessary because of the high chance of coronary artery disease and difficulty in the prediction of coronary artery disease with a severity of the peripheral arteriosclerosis, presence of various risk

  16. Intractable Postpartum Bleeding: A Comparison of the Retrospective Analysis of Angiographic Findings and Transcatheter Arterial Embolization According to Delivery Pattern

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Eun Jung; Kim, Young Hwan; Kim, Si Hyung; Choi, Jin Soo; Park, Jun Cheol; Kwon, Sang Hun; Jo, Chi Heum; Cha, Soon Do [Keimyung University College of Medicine, Daegu (Korea, Republic of)

    2008-12-15

    We evaluated the technical aspect and efficacy of transcatheter arterial embolization (TAE) in cases of intractable postpartum bleeding by comparing the angiographic findings women patients according to their delivery pattern. Between July of 2003 and March of 2008, 55 female patients were enrolled in this study. Of the 55 patients, 36 underwent a vaginal delivery (group 1), whereas 19 underwent a cesarean section delivery (group 2). We retrospectively evaluated the angiographic findings and the embolization technique between groups, using a Pearson Chi-Square test. Medical records and telephone interview findings were also reviewed to evaluate the efficacy of TAE and the outcome of fertility. Significantly greater positive angiographic findings were found in group 2 (63.2%) relative to group 1 (30.6%). For positive angiographic findings, except for AVM, the embolization was performed using coil or glue with gelfoam. For the negative angiographic findings or AVM, the gelfoam was the only embolic agent used. In all patients except for one, bleeding stopped after embolization. Major complications occurred in 2 patients only, and included uterine synechia and perforation. All patients except for one recovered after menstruation. In total, four patients became pregnant and one patient delivered a healthy infant. Positive angiographic findings requiring embolization with coil or glue, as well as gelfoam, were more commonly encountered in group 2 than in group 1. Based on the outcome of the study group, TAE is a safe and effective treatment for intractable postpartum bleeding and is also useful for preserving fertility.

  17. Intractable Postpartum Bleeding: A Comparison of the Retrospective Analysis of Angiographic Findings and Transcatheter Arterial Embolization According to Delivery Pattern

    International Nuclear Information System (INIS)

    Ahn, Eun Jung; Kim, Young Hwan; Kim, Si Hyung; Choi, Jin Soo; Park, Jun Cheol; Kwon, Sang Hun; Jo, Chi Heum; Cha, Soon Do

    2008-01-01

    We evaluated the technical aspect and efficacy of transcatheter arterial embolization (TAE) in cases of intractable postpartum bleeding by comparing the angiographic findings women patients according to their delivery pattern. Between July of 2003 and March of 2008, 55 female patients were enrolled in this study. Of the 55 patients, 36 underwent a vaginal delivery (group 1), whereas 19 underwent a cesarean section delivery (group 2). We retrospectively evaluated the angiographic findings and the embolization technique between groups, using a Pearson Chi-Square test. Medical records and telephone interview findings were also reviewed to evaluate the efficacy of TAE and the outcome of fertility. Significantly greater positive angiographic findings were found in group 2 (63.2%) relative to group 1 (30.6%). For positive angiographic findings, except for AVM, the embolization was performed using coil or glue with gelfoam. For the negative angiographic findings or AVM, the gelfoam was the only embolic agent used. In all patients except for one, bleeding stopped after embolization. Major complications occurred in 2 patients only, and included uterine synechia and perforation. All patients except for one recovered after menstruation. In total, four patients became pregnant and one patient delivered a healthy infant. Positive angiographic findings requiring embolization with coil or glue, as well as gelfoam, were more commonly encountered in group 2 than in group 1. Based on the outcome of the study group, TAE is a safe and effective treatment for intractable postpartum bleeding and is also useful for preserving fertility

  18. Serum high sensitivity C-reactive protein levels and the severity of coronary atherosclerosis assessed by angiographic gensini score

    International Nuclear Information System (INIS)

    Masood, A.; Jafar, S.S.; Akram, Z.

    2011-01-01

    Objective: To assess the relationship between plasma high sensitivity C-reactive protein levels with severity of coronary atherosclerosis. Materials and Methods: The study included 80 patients subjected to coronary angiography. The extent of Coronary Artery Disease (CAD) was assessed using Gensini score. Patients were divided into three risk groups according to hs-CRP levels ( 3mg/L- as high risk). Mean Angiographic Gensini scores were compared among the risk groups. Correlation between serum hs-CRP levels and angiographic Gensini scores was also assessed. Results: The 26 (32.5%) patients belonging to hs-CRP low-risk group had a mean angiographic Gensini score of 11.8 +- 5.8, 18 (22.5%) belonging to moderate-risk group had a mean score of 28.9 +- 7.9 and 36 (45%) belonging to high- risk group had a mean score of 78.7 +- 41.0. By applying ANOVA the mean angiographic Gensini scores showed increasing trend from lower to higher hs-CRP risk groups (p < 0.001). Serum hs-CRP levels showed significant correlation with respective angiographic Gensini scores by Pearson's correlation (p < 0.001). Conclusion: Serum hs-CRP levels show significant correlation with the severity of Coronary Artery Disease as assessed by angiographic Gensini score. (author)

  19. Angiographically Negative Acute Arterial Upper and Lower Gastrointestinal Bleeding: Incidence, Predictive Factors, and Clinical Outcomes

    International Nuclear Information System (INIS)

    Kim, Jin Hyoung; Shin, Ji Hoon; Yoon, Hyun Ki; Chae, Eun Young; Myung, Seung Jae; Ko, Gi Young; Gwon, Dong Il; Sung, Kyu Bo

    2009-01-01

    To evaluate the incidence, predictive factors, and clinical outcomes of angiographically negative acute arterial upper and lower gastrointestinal (GI) bleeding. From 2001 to 2008, 143 consecutive patients who underwent an angiography for acute arterial upper or lower GI bleeding were examined. The angiographies revealed a negative bleeding focus in 75 of 143 (52%) patients. The incidence of an angiographically negative outcome was significantly higher in patients with a stable hemodynamic status (p < 0.001), or in patients with lower GI bleeding (p = 0.032). A follow-up of the 75 patients (range: 0-72 months, mean: 8 ± 14 months) revealed that 60 of the 75 (80%) patients with a negative bleeding focus underwent conservative management only, and acute bleeding was controlled without rebleeding. Three of the 75 (4%) patients underwent exploratory surgery due to prolonged bleeding; however, no bleeding focus was detected. Rebleeding occurred in 12 of 75 (16%) patients. Of these, six patients experienced massive rebleeding and died of disseminated intravascular coagulation within four to nine hours after the rebleeding episode. Four of the 16 patients underwent a repeat angiography and the two remaining patients underwent a surgical intervention to control the bleeding. Angiographically negative results are relatively common in patients with acute GI bleeding, especially in patients with a stable hemodynamic status or lower GI bleeding. Most patients with a negative bleeding focus have experienced spontaneous resolution of their condition

  20. Hepatic angiographic findings of ruptured hepatocellular carcinoma: 'Sentinel signs' versus extravasation

    International Nuclear Information System (INIS)

    Yun, Seong Jong; Nam, Deok Ho

    2014-01-01

    This study retrospectively compared the accuracy of angiographic sentinel signs (sentinel vessels, hypovascular areas, and delayed dots) with extravasation in the diagnosis of ruptured hepatocellular carcinoma (HCC). Sixteen patients diagnosed with HCC between March 2007 and November 2011 were evaluated. Among the patients, we identified 32 HCCs (19 ruptured, 13 unruptured), and assessed all HCCs by hepatic angiography with regard to extravasation, sentinel vessels, hypovascular areas, and delayed dots. We compared the sensitivity and specificity of the sentinel signs with those of the extravasation for the diagnosis of a ruptured HCC. For the angiographic diagnosis of a ruptured HCC, the sensitivity of the sentinel signs (sentinel vessel, 63.2%; hypovascular area, 89.5%; delayed dot, 72.7%) was higher than the sensitivity of extravasation (15.8%). The difference in sensitivity between each sentinel sign and extravasation was statistically significant (sentinel vessel, p = 0.012; hypovascular area, p < 0.001; delayed dot, p 0.039). The specificity of sentinel signs for the diagnosis of ruptured HCC was not statistically different from the specificity of extravasation. Sentinel signs are more accurate than extravasation for the angiographic diagnosis of a ruptured HCC.

  1. The zero-wall puncture: a novel angiographic puncture technique with substantial benefits

    International Nuclear Information System (INIS)

    Leswick, D.A.; Szkup, P.; Stoneham, G.W.

    2005-01-01

    Medical education can be busy, exhausting, and stressful, with potential adverse effects on trainees' physical and mental health. Radiology residency is no exception. In addition to increased daily workload and study requirements, Canadian radiology residents are performing a diverse and increasing number of emergent diagnostic examinations after hours. In an attempt to improve resident self-worth and efficiency during angiographic rotations, we investigated the effects of a novel angiographic puncture procedure on various resident lifestyle indexes. Standard techniques for accessing the femoral artery are either the single-wall puncture or double-wall puncture (Seldinger technique). Both of these techniques are widely known and practiced. Following procedure completion, hemostasis must be achieved at the puncture site. This has traditionally required manual compression at the puncture site, which may require 15 to 20 minutes. At our institution the standard policy is that 'whoever makes the puncture, compresses the groin,' also known as 'you broke it, you fix it'. This has prompted our industrious resident complement to develop a novel, previously undescribed, angiographic puncture technique known as the 'zero-wall puncture technique.' Preliminary unpublished results from our institution show that when residents employ the zero-wall puncture technique the attending staff radiologist subsequently both performs the puncture and compresses the groin at the end of the procedure. We investigated the effect of zero-wall puncture on various resident lifestyle indexes. (author)

  2. Insertion of central venous catheters for hemodialysis using angiographic techniques in patients with previous multiple catheterizations

    International Nuclear Information System (INIS)

    Kotsikoris, Ioannis; Zygomalas, Apollon; Papas, Theofanis; Maras, Dimitris; Pavlidis, Polyvios; Andrikopoulou, Maria; Tsanis, Antonis; Alivizatos, Vasileios; Bessias, Nikolaos

    2012-01-01

    Introduction: Central venous catheter placement is an effective alternative vascular access for dialysis in patients with chronic renal failure. The purpose of this study was to evaluate the insertion of central venous catheters for hemodialysis using angiographic techniques in patients with previous multiple catheterizations in terms of efficacy of the procedure and early complications. Materials and methods: Between 2008 and 2010, the vascular access team of our hospital placed 409 central venous catheters in patients with chronic renal failure. The procedure was performed using the Seldinger blind technique. In 18 (4.4%) cases it was impossible to advance the guidewire, and so the patients were transported to the angiography suite. Results: Using the angiographic technique, the guidewire was advanced in order to position the central venous catheter. The latter was inserted into the subclavian vein in 12 (66.6%) cases, into the internal jugular vein in 4 (22.2%) and into the femoral vein in 2 (11.1%) cases. There was only one complicated case with severe arrhythmia in 1 (5.5%) patient. Conclusion: Our results suggest that insertion of central venous catheters using angiographic techniques in hemodialysis patients with previous multiple catheterizations is a safe and effective procedure with few complications and high success rates

  3. Insertion of central venous catheters for hemodialysis using angiographic techniques in patients with previous multiple catheterizations

    Energy Technology Data Exchange (ETDEWEB)

    Kotsikoris, Ioannis, E-mail: gkotsikoris@gmail.com [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece); Zygomalas, Apollon, E-mail: azygomalas@upatras.gr [Department of General Surgery, University Hospital of Patras (Greece); Papas, Theofanis, E-mail: pfanis@otenet.gr [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece); Maras, Dimitris, E-mail: dimmaras@gmail.com [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece); Pavlidis, Polyvios, E-mail: polpavlidis@yahoo.gr [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece); Andrikopoulou, Maria, E-mail: madric@gmail.com [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece); Tsanis, Antonis, E-mail: atsanis@gmail.com [Department of Interventional Radiology, “Erythros Stauros” General Hospital (Greece); Alivizatos, Vasileios, E-mail: valiviz@hol.gr [Department of General Surgery and Artificial Nutrition Unit, “Agios Andreas” General Hospital of Patras (Greece); Bessias, Nikolaos, E-mail: bessias@otenet.gr [Department of Vascular Surgery, “Erythros Stauros” General Hospital (Greece)

    2012-09-15

    Introduction: Central venous catheter placement is an effective alternative vascular access for dialysis in patients with chronic renal failure. The purpose of this study was to evaluate the insertion of central venous catheters for hemodialysis using angiographic techniques in patients with previous multiple catheterizations in terms of efficacy of the procedure and early complications. Materials and methods: Between 2008 and 2010, the vascular access team of our hospital placed 409 central venous catheters in patients with chronic renal failure. The procedure was performed using the Seldinger blind technique. In 18 (4.4%) cases it was impossible to advance the guidewire, and so the patients were transported to the angiography suite. Results: Using the angiographic technique, the guidewire was advanced in order to position the central venous catheter. The latter was inserted into the subclavian vein in 12 (66.6%) cases, into the internal jugular vein in 4 (22.2%) and into the femoral vein in 2 (11.1%) cases. There was only one complicated case with severe arrhythmia in 1 (5.5%) patient. Conclusion: Our results suggest that insertion of central venous catheters using angiographic techniques in hemodialysis patients with previous multiple catheterizations is a safe and effective procedure with few complications and high success rates.

  4. Variations of Patient Doses in Interventional Examinations at Different Angiographic Units

    International Nuclear Information System (INIS)

    Bor, Dogan; Toklu, Tuerkay; Olgar, Turan; Sancak, Tanzer; Cekirge, Saruhan; Onal, Baran; Bilgic, Sadik

    2006-01-01

    Purpose. We analyzed doses for various angiographic procedures using different X-ray systems in order to assess dose variations. Methods. Dose-area product (DAP), skin doses from thermoluminescent dosimeters and air kerma measurements of 308 patients (239 diagnostic and 69 interventional) were assessed for five different angiographic units. All fluoroscopic and radiographic exposure parameters were recorded online for single and multiprojection studies. Radiation outputs of each X-ray system were also measured for all the modes of exposure using standard protocols for such measurements. Results. In general, the complexity of the angiographic procedure was found to be the most important reason for high radiation doses. Skill of the radiologist, management of the exposure parameters and calibration of the system are the other factors to be considered. Lateral cerebral interventional studies carry the highest risk for deterministic effects on the lens of the eye. Effective doses were calculated from DAP measurements and maximum fatal cancer risk factors were found for carotid studies. Conclusions. Interventional radiologists should measure patient doses for their examinations. If there is a lack of necessary instrumentation for this purpose, then published dose reports should be used in order to predict the dose levels from some of the exposure parameters. Patient dose information should include not only the measured quantity but also the measured radiation output of the X-ray unit and exposure parameters used during radiographic and fluoroscopic exposures

  5. Angiographically Negative Acute Arterial Upper and Lower Gastrointestinal Bleeding: Incidence, Predictive Factors, and Clinical Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hyoung; Shin, Ji Hoon; Yoon, Hyun Ki; Chae, Eun Young; Myung, Seung Jae; Ko, Gi Young; Gwon, Dong Il; Sung, Kyu Bo [Asan Medical Center, Seoul (Korea, Republic of)

    2009-08-15

    To evaluate the incidence, predictive factors, and clinical outcomes of angiographically negative acute arterial upper and lower gastrointestinal (GI) bleeding. From 2001 to 2008, 143 consecutive patients who underwent an angiography for acute arterial upper or lower GI bleeding were examined. The angiographies revealed a negative bleeding focus in 75 of 143 (52%) patients. The incidence of an angiographically negative outcome was significantly higher in patients with a stable hemodynamic status (p < 0.001), or in patients with lower GI bleeding (p = 0.032). A follow-up of the 75 patients (range: 0-72 months, mean: 8 {+-} 14 months) revealed that 60 of the 75 (80%) patients with a negative bleeding focus underwent conservative management only, and acute bleeding was controlled without rebleeding. Three of the 75 (4%) patients underwent exploratory surgery due to prolonged bleeding; however, no bleeding focus was detected. Rebleeding occurred in 12 of 75 (16%) patients. Of these, six patients experienced massive rebleeding and died of disseminated intravascular coagulation within four to nine hours after the rebleeding episode. Four of the 16 patients underwent a repeat angiography and the two remaining patients underwent a surgical intervention to control the bleeding. Angiographically negative results are relatively common in patients with acute GI bleeding, especially in patients with a stable hemodynamic status or lower GI bleeding. Most patients with a negative bleeding focus have experienced spontaneous resolution of their condition.

  6. JUMPING THE CURVE

    Directory of Open Access Journals (Sweden)

    René Pellissier

    2012-01-01

    Full Text Available This paper explores the notion ofjump ing the curve,following from Handy 's S-curve onto a new curve with new rules policies and procedures. . It claims that the curve does not generally lie in wait but has to be invented by leadership. The focus of this paper is the identification (mathematically and inferentially ofthat point in time, known as the cusp in catastrophe theory, when it is time to change - pro-actively, pre-actively or reactively. These three scenarios are addressed separately and discussed in terms ofthe relevance ofeach.

  7. Tornado-Shaped Curves

    Science.gov (United States)

    Martínez, Sol Sáez; de la Rosa, Félix Martínez; Rojas, Sergio

    2017-01-01

    In Advanced Calculus, our students wonder if it is possible to graphically represent a tornado by means of a three-dimensional curve. In this paper, we show it is possible by providing the parametric equations of such tornado-shaped curves.

  8. Simulating Supernova Light Curves

    International Nuclear Information System (INIS)

    Even, Wesley Paul; Dolence, Joshua C.

    2016-01-01

    This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth's atmosphere.

  9. Simulating Supernova Light Curves

    Energy Technology Data Exchange (ETDEWEB)

    Even, Wesley Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dolence, Joshua C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-05

    This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth’s atmosphere.

  10. Image scaling curve generation

    NARCIS (Netherlands)

    2012-01-01

    The present invention relates to a method of generating an image scaling curve, where local saliency is detected in a received image. The detected local saliency is then accumulated in the first direction. A final scaling curve is derived from the detected local saliency and the image is then

  11. Image scaling curve generation.

    NARCIS (Netherlands)

    2011-01-01

    The present invention relates to a method of generating an image scaling curve, where local saliency is detected in a received image. The detected local saliency is then accumulated in the first direction. A final scaling curve is derived from the detected local saliency and the image is then

  12. Tempo curves considered harmful

    NARCIS (Netherlands)

    Desain, P.; Honing, H.

    1993-01-01

    In the literature of musicology, computer music research and the psychology of music, timing or tempo measurements are mostly presented in the form of continuous curves. The notion of these tempo curves is dangerous, despite its widespread use, because it lulls its users into the false impression

  13. The curve shortening problem

    CERN Document Server

    Chou, Kai-Seng

    2001-01-01

    Although research in curve shortening flow has been very active for nearly 20 years, the results of those efforts have remained scattered throughout the literature. For the first time, The Curve Shortening Problem collects and illuminates those results in a comprehensive, rigorous, and self-contained account of the fundamental results.The authors present a complete treatment of the Gage-Hamilton theorem, a clear, detailed exposition of Grayson''s convexity theorem, a systematic discussion of invariant solutions, applications to the existence of simple closed geodesics on a surface, and a new, almost convexity theorem for the generalized curve shortening problem.Many questions regarding curve shortening remain outstanding. With its careful exposition and complete guide to the literature, The Curve Shortening Problem provides not only an outstanding starting point for graduate students and new investigations, but a superb reference that presents intriguing new results for those already active in the field.

  14. Transport properties of the continuous-time random walk with a long-tailed waiting-time density

    International Nuclear Information System (INIS)

    Weissman, H.; Havlin, S.; Weiss, G.H.

    1989-01-01

    The authors derive asymptotic properties of the propagator p(r, t) of a continuous-time random walk (CTRW) in which the waiting time density has the asymptotic form ψ(t) ∼ T α /t α+1 when t >> T and 0 = ∫ 0 ∞ τψ(τ)dτ is finite. One is that the asymptotic behavior of p(0, t) is demonstrated by the waiting time at the origin rather than by the dimension. The second difference is that in the presence of a field p(r, t) no longer remains symmetric around a moving peak. Rather, it is shown that the peak of this probability always occurs at r = 0, and the effect of the field is to break the symmetry that occurs when < ∞. Finally, they calculate similar properties, although in not such great detail, for the case in which the single-step jump probabilities themselves have an infinite mean

  15. Learning Curve? Which One?

    Directory of Open Access Journals (Sweden)

    Paulo Prochno

    2004-07-01

    Full Text Available Learning curves have been studied for a long time. These studies provided strong support to the hypothesis that, as organizations produce more of a product, unit costs of production decrease at a decreasing rate (see Argote, 1999 for a comprehensive review of learning curve studies. But the organizational mechanisms that lead to these results are still underexplored. We know some drivers of learning curves (ADLER; CLARK, 1991; LAPRE et al., 2000, but we still lack a more detailed view of the organizational processes behind those curves. Through an ethnographic study, I bring a comprehensive account of the first year of operations of a new automotive plant, describing what was taking place on in the assembly area during the most relevant shifts of the learning curve. The emphasis is then on how learning occurs in that setting. My analysis suggests that the overall learning curve is in fact the result of an integration process that puts together several individual ongoing learning curves in different areas throughout the organization. In the end, I propose a model to understand the evolution of these learning processes and their supporting organizational mechanisms.

  16. The crime kuznets curve

    OpenAIRE

    Buonanno, Paolo; Fergusson, Leopoldo; Vargas, Juan Fernando

    2014-01-01

    We document the existence of a Crime Kuznets Curve in US states since the 1970s. As income levels have risen, crime has followed an inverted U-shaped pattern, first increasing and then dropping. The Crime Kuznets Curve is not explained by income inequality. In fact, we show that during the sample period inequality has risen monotonically with income, ruling out the traditional Kuznets Curve. Our finding is robust to adding a large set of controls that are used in the literature to explain the...

  17. Bond yield curve construction

    Directory of Open Access Journals (Sweden)

    Kožul Nataša

    2014-01-01

    Full Text Available In the broadest sense, yield curve indicates the market's view of the evolution of interest rates over time. However, given that cost of borrowing it closely linked to creditworthiness (ability to repay, different yield curves will apply to different currencies, market sectors, or even individual issuers. As government borrowing is indicative of interest rate levels available to other market players in a particular country, and considering that bond issuance still remains the dominant form of sovereign debt, this paper describes yield curve construction using bonds. The relationship between zero-coupon yield, par yield and yield to maturity is given and their usage in determining curve discount factors is described. Their usage in deriving forward rates and pricing related derivative instruments is also discussed.

  18. SRHA calibration curve

    Data.gov (United States)

    U.S. Environmental Protection Agency — an UV calibration curve for SRHA quantitation. This dataset is associated with the following publication: Chang, X., and D. Bouchard. Surfactant-Wrapped Multiwalled...

  19. Bragg Curve Spectroscopy

    International Nuclear Information System (INIS)

    Gruhn, C.R.

    1981-05-01

    An alternative utilization is presented for the gaseous ionization chamber in the detection of energetic heavy ions, which is called Bragg Curve Spectroscopy (BCS). Conceptually, BCS involves using the maximum data available from the Bragg curve of the stopping heavy ion (HI) for purposes of identifying the particle and measuring its energy. A detector has been designed that measures the Bragg curve with high precision. From the Bragg curve the range from the length of the track, the total energy from the integral of the specific ionization over the track, the dE/dx from the specific ionization at the beginning of the track, and the Bragg peak from the maximum of the specific ionization of the HI are determined. This last signal measures the atomic number, Z, of the HI unambiguously

  20. ROBUST DECLINE CURVE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Sutawanir Darwis

    2012-05-01

    Full Text Available Empirical decline curve analysis of oil production data gives reasonable answer in hyperbolic type curves situations; however the methodology has limitations in fitting real historical production data in present of unusual observations due to the effect of the treatment to the well in order to increase production capacity. The development ofrobust least squares offers new possibilities in better fitting production data using declinecurve analysis by down weighting the unusual observations. This paper proposes a robustleast squares fitting lmRobMM approach to estimate the decline rate of daily production data and compares the results with reservoir simulation results. For case study, we usethe oil production data at TBA Field West Java. The results demonstrated that theapproach is suitable for decline curve fitting and offers a new insight in decline curve analysis in the present of unusual observations.

  1. Power Curve Measurements FGW

    DEFF Research Database (Denmark)

    Georgieva Yankova, Ginka; Federici, Paolo

    This report describes power curve measurements carried out on a given turbine in a chosen period. The measurements are carried out in accordance to IEC 61400-12-1 Ed. 1 and FGW Teil 2.......This report describes power curve measurements carried out on a given turbine in a chosen period. The measurements are carried out in accordance to IEC 61400-12-1 Ed. 1 and FGW Teil 2....

  2. Curves and Abelian varieties

    CERN Document Server

    Alexeev, Valery; Clemens, C Herbert; Beauville, Arnaud

    2008-01-01

    This book is devoted to recent progress in the study of curves and abelian varieties. It discusses both classical aspects of this deep and beautiful subject as well as two important new developments, tropical geometry and the theory of log schemes. In addition to original research articles, this book contains three surveys devoted to singularities of theta divisors, of compactified Jacobians of singular curves, and of "strange duality" among moduli spaces of vector bundles on algebraic varieties.

  3. Angiographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid artery

    International Nuclear Information System (INIS)

    Na, Dong Gyu; Han, Moon Hee; Chang, Kee Hyun; Han, Gi Seok; Yeon, Kung Mo

    1995-01-01

    The purpose of this study is to describe the angiographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid arteries and to evaluate the extent of angiographic assessment needed before embolization. We retrospectively reviewed 10 cervicofacial vascular lesions with previously ligated carotid artery, which were 6 cases of arteriovenous malformation, 2 cases of carotid cavernous fistula, 1 case of hemangioma and 1 case of arteriovenous malformation with carotid cavernous fistula. The previously ligated arteries are proximal external carotid artery (n = 5), branches of external carotid artery (n = 2) and common carotid artery (n = 3). Common carotid artery or internal carotid artery (n = 9), vertebral artery (n = 5), ipsilateral external carotid artery (n = 4), contralateral external carotid artery (n = 5), costocervical trunk (n = 2), thyrocervical trunk (n = 2) were assessed by conventional angiography. Angiography of both carotid and vertebral arteries was performed in 5 cases. The collateral vascular channels were inferolateral trunk of internal carotid artery (n = 8), vertebral artery (n = 5), contralateral external carotid artery (n = 5), ipsilateral external carotid artery (n = 4), deep cervical artery (n = 2) and ascending cervical artery (n = 1). Embolization were performed in 9 cases with operative cannulation (n = 4), embolization via collateral branches of ipsilateral external carotid artery (n = 1), embolization via collateral branches of contralateral external carotid artery (n = 3) and balloon occlusion via direct puncture (n = 1). The collateral channels in cervicofacial vascular lesions with previously ligated carotid artery were inferolateral trunk of internal carotid artery, contralateral or ipsilateral external carotid artery, vertebral artery, deep cervical artery and ascending cervical artery on angiography. Complete angiographic assessment of possible collateral channels is mandatory for the

  4. Quantitative 4D Transcatheter Intraarterial Perfusion MR Imaging as a Method to Standardize Angiographic Chemoembolization Endpoints

    Science.gov (United States)

    Jin, Brian; Wang, Dingxin; Lewandowski, Robert J.; Ryu, Robert K.; Sato, Kent T.; Larson, Andrew C.; Salem, Riad; Omary, Reed A.

    2011-01-01

    PURPOSE We aimed to test the hypothesis that subjective angiographic endpoints during transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC) exhibit consistency and correlate with objective intraprocedural reductions in tumor perfusion as determined by quantitative four dimensional (4D) transcatheter intraarterial perfusion (TRIP) magnetic resonance (MR) imaging. MATERIALS AND METHODS This prospective study was approved by the institutional review board. Eighteen consecutive patients underwent TACE in a combined MR/interventional radiology (MR-IR) suite. Three board-certified interventional radiologists independently graded the angiographic endpoint of each procedure based on a previously described subjective angiographic chemoembolization endpoint (SACE) scale. A consensus SACE rating was established for each patient. Patients underwent quantitative 4D TRIP-MR imaging immediately before and after TACE, from which mean whole tumor perfusion (Fρ) was calculated. Consistency of SACE ratings between observers was evaluated using the intraclass correlation coefficient (ICC). The relationship between SACE ratings and intraprocedural TRIP-MR imaging perfusion changes was evaluated using Spearman’s rank correlation coefficient. RESULTS The SACE rating scale demonstrated very good consistency among all observers (ICC = 0.80). The consensus SACE rating was significantly correlated with both absolute (r = 0.54, P = 0.022) and percent (r = 0.85, P SACE rating scale demonstrates very good consistency between raters, and significantly correlates with objectively measured intraprocedural perfusion reductions during TACE. These results support the use of the SACE scale as a standardized alternative method to quantitative 4D TRIP-MR imaging to classify patients based on embolic endpoints of TACE. PMID:22021520

  5. IMPORTANCE OF KNOWING ANGIOGRAPHIC CHARACTERISTICS OF THE TENSOR FASCIAE LATAE VASCULAR STALK

    Directory of Open Access Journals (Sweden)

    Sladjana Ugrenovic

    2006-07-01

    Full Text Available Atherosclerosis is the most important and most common type of arteriosclerosis and is a general term for several diseases in which the artery wall becomes thicker and less elastic. The most common location of atherosclerosis occurrence is arteries of lower extremities, while arteries of upper extremities as well as visceral arteries are far less and far rarely affected with this degenerative process.The most frequent ones are occlusive changes on bifurcation of the abdominal aorta (aortoiliac obstructive atherosclerosis “Morbus Leriche”, trunk of the femoral artery and initial part of the popliteal artery (femoropopliteal obstructive atherosclerosis.Angiography, as additional method in medicine, gives the most precise insight into anatomical changes on blood vessels. With intention of estimating the possibility of using a slice (lobe part of the tensor fasciae latae (m. TFL in plastic and reconstructive surgery, we have analyzed 50 angiograms of femoral artery. The first group included Morbus Leriche patients (25 analyzed angiographics, while the second one comprised patients with femoropopliteal segment disease (also 25 analyzed angiographics. With angiographic analysis of the lateral femoral circumflex artery (LCFA and its branch, which is dominant in vascularisation of m. TFL slice, we discovered that the diameter of its source, as well as of its branches, is bigger in cases of femoropopliteal segment disease. Then, the reduction of the source diameter of LCFA and its branches, caused by vascular disease, leads to decreased blood supply of m. TFL, diminishing its quality and limiting its usage in surgery.In Morbus Leriche cases, m. TFL slice cannot be used in plastic and reconstructive surgery, its quality being decreased, due to poor vascularization. In femoropopliteal segment disease cases, thanks to normal blood supply, m. TFL slice can be widely used for reconstructions or covering of defects, especially in inguinal region, which is

  6. Unsatisfactory hepatic perfusion after placement of the infusaid pump: Angiographic correlation

    International Nuclear Information System (INIS)

    Andrews, J.C.; Williams, D.M.; Cho, K.J.; Knol, J.A.; Wahl, R.L.; Ensminger, W.D.

    1988-01-01

    Complete perfusion limited to the liver is essential to the success of regional chemotherapy for hepatic malignancy. Thirty-three patients with unsatisfactory hepatic artery perfusion scintigrams after surgical placement of a pump and catheter system were evaluated with selective angiography (31 cases) or digital subtraction angiography (DSA) via the pump side port (six cases). The cause of the perfusion defect was hepatic artery thrombosis (14 cases), extrahepatic flow through collaterals (13 cases), misplaced catheter (three cases), short proper hepatic artery without adequate length for mixing (two cases), and undefined (one case). DSA findings were diagnostic in only two cases. Angiographic findings directed attempted correction in 22 of 33 cases

  7. Approximation by planar elastic curves

    DEFF Research Database (Denmark)

    Brander, David; Gravesen, Jens; Nørbjerg, Toke Bjerge

    2016-01-01

    We give an algorithm for approximating a given plane curve segment by a planar elastic curve. The method depends on an analytic representation of the space of elastic curve segments, together with a geometric method for obtaining a good initial guess for the approximating curve. A gradient......-driven optimization is then used to find the approximating elastic curve....

  8. Power Curve Measurements REWS

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Vesth, Allan

    This report describes the power curve measurements carried out on a given wind turbine in a chosen period. The measurements were carried out following the measurement procedure in the draft of IEC 61400-12-1 Ed.2 [1], with some deviations mostly regarding uncertainty calculation. Here, the refere......This report describes the power curve measurements carried out on a given wind turbine in a chosen period. The measurements were carried out following the measurement procedure in the draft of IEC 61400-12-1 Ed.2 [1], with some deviations mostly regarding uncertainty calculation. Here......, the reference wind speed used in the power curve is the equivalent wind speed obtained from lidar measurements at several heights between lower and upper blade tip, in combination with a hub height meteorological mast. The measurements have been performed using DTU’s measurement equipment, the analysis...

  9. Feasibility and Safety of Transradial Arterial Approach for Simultaneous Right and Left Vertebral Artery Angiographic Studies and Stenting

    International Nuclear Information System (INIS)

    Yip, H.-K.; Youssef, Ali A.; Chang, W.-N.; Lu, C.-H.; Yang, C.-H.; Chen, S.-M.; Wu, C.-J.

    2007-01-01

    Objectives. This study investigated whether the transradial artery (TRA) approach using a 6-French (F) Kimny guiding catheter for right vertebral artery (VA) angiographic study and stenting is safe and effective for patients with significant VA stenosis. Background. The TRA approach is commonly performed worldwide for both diagnostic cardiac catheterization and catheter-based coronary intervention. However, to our knowledge, the safety and feasibility of left and right VA angiographic study and stenting, in the same procedure, using the TRA approach for patients with brain ischemia have not been reported. Methods. The study included 24 consecutive patients (22 male, 2 female; age, 63-78 years). Indications for VA angiographic study and stenting were (1) prior stroke or symptoms related to vertebrobasilar ischemia and (2) an asymptomatic but vertebral angiographic finding of severe stenosis (>70%). A combination of the ipsilateral and retrograde-engagement technique, which involved a looping 6-F Kimny guiding catheter, was utilized for VA angiographic study. For VA stenting, an ipsilateral TRA approach with either a Kimny guiding catheter or a left internal mammary artery guiding catheter was utilized in 22 patients and retrograde-engagement technique in 2 patients. Results. A technically successful procedure was achieved in all patients, including left VA stenting in 15 patients and right VA stenting in 9 patients. The mean time for stenting (from engagement to stent deployment) was 12.7 min. There were no vascular complications or mortality. However, one patient suffered from a transient ischemic attack that resolved within 3 h. Conclusion. We conclude that TRA access for both VA angiographic study and VA stenting is safe and effective, and provides a simple and useful clinical tool for patients unsuited for femoral arterial access

  10. Angiographic evaluation

    International Nuclear Information System (INIS)

    Castaneda-Zuniga, W.R.

    1986-01-01

    Failure of a transplanted kidney may be caused by any of several factors requiring different methods of management. It is thus necessary to distinguish between rejection, acute tubular necrosis, obstruction of the main blood vessels in the graft, and obstruction of the ureter. Careful evaluation is particularly important when cadaver kidneys are used, for which the functional 2-year survival rate is only 40-50%, compared with 70-80% for living related donor kidneys. Formerly renal transplant angiography was often performed to differentiate between acute rejection and acute ischemic tubular necrosis as the cause of graft dysfunction in the immediate postoperative period. Now, however, angiography for the patient with a failing graft is restricted mainly to the search for renal artery stenosis and arterial or renal vein thrombosis. Although the study may be specific when a full-blown pattern of rejection is present, routine angiography has proved to be of little value when rejection is suspected

  11. Curved electromagnetic missiles

    International Nuclear Information System (INIS)

    Myers, J.M.; Shen, H.M.; Wu, T.T.

    1989-01-01

    Transient electromagnetic fields can exhibit interesting behavior in the limit of great distances from their sources. In situations of finite total radiated energy, the energy reaching a distant receiver can decrease with distance much more slowly than the usual r - 2 . Cases of such slow decrease have been referred to as electromagnetic missiles. All of the wide variety of known missiles propagate in essentially straight lines. A sketch is presented here of a missile that can follow a path that is strongly curved. An example of a curved electromagnetic missile is explicitly constructed and some of its properties are discussed. References to details available elsewhere are given

  12. Algebraic curves and cryptography

    CERN Document Server

    Murty, V Kumar

    2010-01-01

    It is by now a well-known paradigm that public-key cryptosystems can be built using finite Abelian groups and that algebraic geometry provides a supply of such groups through Abelian varieties over finite fields. Of special interest are the Abelian varieties that are Jacobians of algebraic curves. All of the articles in this volume are centered on the theme of point counting and explicit arithmetic on the Jacobians of curves over finite fields. The topics covered include Schoof's \\ell-adic point counting algorithm, the p-adic algorithms of Kedlaya and Denef-Vercauteren, explicit arithmetic on

  13. IGMtransmission: Transmission curve computation

    Science.gov (United States)

    Harrison, Christopher M.; Meiksin, Avery; Stock, David

    2015-04-01

    IGMtransmission is a Java graphical user interface that implements Monte Carlo simulations to compute the corrections to colors of high-redshift galaxies due to intergalactic attenuation based on current models of the Intergalactic Medium. The effects of absorption due to neutral hydrogen are considered, with particular attention to the stochastic effects of Lyman Limit Systems. Attenuation curves are produced, as well as colors for a wide range of filter responses and model galaxy spectra. Photometric filters are included for the Hubble Space Telescope, the Keck telescope, the Mt. Palomar 200-inch, the SUBARU telescope and UKIRT; alternative filter response curves and spectra may be readily uploaded.

  14. Pattern not volume of bleeding predicts angiographic vasospasm in nonaneurysmal subarachnoid hemorrhage.

    Science.gov (United States)

    Raya, Amanda; Zipfel, Gregory J; Diringer, Michael N; Dacey, Ralph G; Derdeyn, Colin P; Rich, Keith M; Chicoine, Michael R; Dhar, Rajat

    2014-01-01

    Spontaneous idiopathic subarachnoid hemorrhage (SAH) with a perimesencephalic bleeding pattern is usually associated with a benign course, whereas a diffuse bleeding pattern has been associated with a higher risk of vasospasm and disability. We evaluated whether volume of bleeding explains this disparity. Pattern and amount of bleeding (by Hijdra and intraventricular hemorrhage scores) were assessed in 89 patients with nonaneurysmal SAH. Outcomes included angiographic vasospasm, delayed cerebral ischemia, and functional outcome at 1 year. Diffuse bleeding was associated with significantly higher Hijdra and intraventricular hemorrhage scores than perimesencephalic SAH, P≤0.003. Angiographic vasospasm was more likely in diffuse versus perimesencephalic SAH (45% versus 27%; odds ratio, 2.9; P=0.08), but adjustment for greater blood burden only partially attenuated this trend (adjusted odds ratio, 2.2; 95% confidence interval, 0.69-7.2; P=0.18); delayed cerebral ischemia was only seen in those with diffuse bleeding. Patients with diffuse bleeding were less likely to be discharged home (68% versus 90%; P=0.01) and tended to have more residual disability (modified Rankin scale, 3-6; 20% versus 6%; P=0.18). Nonaneurysmal SAH can still result in vasospasm and residual disability, especially in those with diffuse bleeding. This disparity is only partially accounted for by greater cisternal or intraventricular blood, suggesting that the mechanism and distribution of bleeding may be as important as the amount of hemorrhage in patients with idiopathic SAH.

  15. Development of a Portable Training Tool for Simulating Visceral Angiographic Procedures for Beginners

    International Nuclear Information System (INIS)

    Yamagami, Takuji; Osuga, Keigo; Yoshimatsu, Rika; Matsumoto, Tomohiro; Miura, Hiroshi; Terayama, Koshi; Anai, Hiroshi; Takahashi, Masahide; Hasebe, Terumitsu; Nishimura, Tsunehiko

    2009-01-01

    The purpose of this study was to evaluate the usefulness of a tool that we developed to simulate performance of visceral angiography to train beginners in the field of splanchnic angiography. Seven residents and two fellows who were rotating within the Division of Interventional Radiology at our institution between June and August 2008 participated in the evaluation of this tool. They had no experience in performing visceral angiography as an operator. Time for selection of arterial branches arising from the celiac axis on the model was measured before and after training. After such training, the participants performed actual visceral angiography as an operator with instructors beside them. Success of the trainees in selecting visceral arterial branches was evaluated in these real-life cases. In the first test using the model, seven of nine trainees (77.8%) succeeded in selecting all required arteries, while the remaining two failed to select all required arteries. After training using the model, all trainees succeeded in selecting all required arteries just before the actual angiographic study. In the actual angiography, the catheter was successfully inserted from the femoral artery and advanced to the superior mesenteric, celiac, splenic, common hepatic, gastroduodenal, and right and left hepatic arteries by all trainees with only two exceptions. In conclusion, this tool is helpful for training beginners in visceral angiographic procedures.

  16. Angiographic manifestation and transcatheter arterial embolization of proper esophageal artery in hemoptysis

    International Nuclear Information System (INIS)

    Jiang Sen; Zhu Xiaohua; Sun Xiwen; Zhi Wenxiang; Jie Bing; You Zhengqian; Yu Dong; Peng Gang

    2008-01-01

    Objective: To investigate the angiographic manifestation of the proper esophageal artery (PEA), the high risk factors for the presence of the anomalous PEA in hemoptysis and to evaluate the safety of transcatheter arterial embolization (TAE) of the PEA using gelatin sponge (GS). Methods: Selective esophageal arteriography was performed in forty-three patients with hemoptysis, including 15 cases of pulmonary tuberculosis, 18 cases of bronchiectasis, 7 cases of posttuberculous bronchiectasis and three cases of lung cancer. One case experienced failure of bronchial arterial embolization. The angiographic manifestation of the PEAs was studied. The complications of the procedure and clinical results were observed in the patients who underwent TAE using GS. Results: Thirty-nine PEAs were catheterized selectively in 37 patients (86.0%). Eighteen anomalous PEAs (46.2%) were catheterized selectively in 17 patients (45.9%). The anomalous PEAs showed tortuosity, dilatation, hyperplasia, shunting with pulmonary artery and anastomosis with the bronchial artery. All lesions involved basal segment of inferior pulmonary lobar. Bronchiectasis was the most frequent disease for PEA abnormality. No complications occurred and satisfactory curative effect was achieved with TAE of the anomalous PEAs. Conclusions: It is necessary to perform selective proper esophageal arteriography when the lesion involves basal segment of inferior pulmonary lobar in hemoptysis. Supplemental TAE of the anomalous PEA using GS is safe and valuable in the management of hemoptysis. (authors)

  17. Early Angiographic Resolution of Cerebral Vasospasm with High Dose Intravenous Milrinone Therapy

    Directory of Open Access Journals (Sweden)

    F. A. Zeiler

    2015-01-01

    Full Text Available Background. Treatment of symptomatic delayed cerebral ischemia (DCI after subarachnoid hemorrhage (SAH is difficult. Recent studies suggest intravenous (IV high dose milrinone as a potential therapy. The timing to angiographic response with this is unclear. Methods. We reviewed the chart of one patient admitted for SAH who developed symptomatic DCI and was treated with high dose IV milrinone. Results. A 66-year-old female was admitted with a Hunt and Hess clinical grade 4, World Federation of Neurological Surgeons (WFNS clinical grade 4, and SAH secondary to a left anterior choroidal artery aneurysm which was clipped. After bleed day 6, the patient developed symptomatic DCI. We planned for angioplasty of the proximal segments. We administered high dose IV milrinone bolus followed by continuous infusion which led to clinical improvement prior to angiography. The angiogram performed 1.5 hours after milrinone administration displayed resolution of the CT angiogram and MRI based cerebral vasospasm such that further intra-arterial therapy was aborted. She completed 6 days of continuous IV milrinone therapy, was transferred to the ward, and subsequently rehabilitated. Conclusions. High dose IV milrinone therapy for symptomatic DCI after SAH can lead to rapid neurological improvement with dramatic early angiographic improvement of cerebral vasospasm.

  18. The association of elastin gene variants with two angiographic subtypes of polypoidal choroidal vasculopathy.

    Directory of Open Access Journals (Sweden)

    Suiho Yanagisawa

    Full Text Available To compare the association of elastin (ELN gene variants between two different angiographic phenotypes of polypoidal choroidal vasculopathy (PCV.We included 411 treatment-naïve PCV patients and 350 controls in the present study. PCV was classified into two phenotypes (152 Type 1 and 259 Type 2 according to the presence or absence of feeding vessels found in indocyanine-green angiography. Single nucleotide polymorphisms (SNPs in the ELN region including rs868005, rs884843, rs2301995, rs13239907 and rs2856728 were genotyped using TaqMan Genotyping Assays.In the allelic association analyses, rs868005 showed the strongest association with Type 2 PCV (allelic odds ratio 1.56; p = 7.4x10(-6, while no SNP was significantly associated with Type 1 PCV. Genotype association analyses revealed the significant association of rs868005 with Type 2 PCV in log additive model and predominant model (odds ratio 1.75; p = 1.5x10(-6 and odds ratio 1.60; p = 0.0044, respectively, but not with Type 1 PCV. These findings were further corroborated by another control group in the literature.There may be significantly different associations in genetic variants of elastin between two angiographic phenotypes of PCV.

  19. Internal carotid arterial occlusion in computed tomography. Correlation of CT and angiographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Harada, K.; Miura, T.; Nishikubo, Y.; Kawai, R.; Mitomo, M. (Osaka Univ. (Japan). Faculty of Medicine)

    1981-09-01

    The computed tomographic appearance of internal carotid arterial occlusion was reviewed in 33 patients. In 23 of them, who underwent 4-vessel study, the angiographic and CT findings were compared. Ten patients were disclosed to have watershed infarction by CT. Seven of them had watershed processes in the centrum semiovale which were considered to be terminal infarction. Patients who showed watershed infarction under CT revealed inadequate circle of Willis and well-developed cortical anastomosis under angiography. Unilaterally accentuated cerebral atrophy, which we have called asymmetrical atrophy in this paper, was noted in 10 patients. The findings of asymmetrical cerebral atrophy sometimes resemble the changes secondary to old infarction. However, the changes in the lateral ventricle caused by asymmetrical cerebral atrophy are somewhat different from those resulting from old infarction. The angiographic findings suggested that asymmetrical cerebral atrophy is, in addition to being associated with incomplete circle of Willis, also associated with local circulatory disturbances which further decrease the regional cerebral blood flow in the affected hemisphere.

  20. Corrected thrombolysis in myocardial infarction frame counts in diabetic patients with angiographically normal coronary arteries

    International Nuclear Information System (INIS)

    Turkoglu, S.; Ozdemir, M.; Tacoy, G.; Tavil, Y.; Abaci, A.; Timurkaynak, T.; Cengel, A.

    2008-01-01

    Objective was to evaluate corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) in patients with angiographically normal coronary arteries and diabetes mellitus, a condition known to be associated with microvascular dysfunction. Patients who underwent coronary angiography in Gazi University Hospital, Ankara, Turkey between January 2000 and January 2005 were studied. Corrected TIMI frame count was left circumflex (Cx) and right coronary arteries (RCA) in 118 diabetic and 122 non-diabetic patients with normal coronary angiogram. The mean CTFC values of the LAD, Cx and the RCA were similar in diabetics and nondiabetics (21.0+-7.5 versus 21.3+-9.6, 23.3+-9.7 versus 23.5+-10.8, 17.9+-6.7 versus 18.7+-7.4 respectively, p>0.05 for all comparisons). In stepwise multivariate linear regression analysis, body surface area had a significant correlation with CTFC of all the 3 coronary arteries. We conclude that CTFC in diabetics and non-diabetics with angiographically normal coronary arteries is similar. Since microvascular disease is an inherent component of diabetes, our finding may reflect the inadequacy of CTFC in predicting microvascular disease in diabetic patients with normal coronary angiograms. (author)

  1. Angiographic characteristics of premature coronary artery disease in pakistan population; a prospective cross-sectional study

    International Nuclear Information System (INIS)

    Mustafa, B.; Rahman, H.U.

    2015-01-01

    Objective: To study the angiographic characteristics of premature coronary artery disease in our population. Methodology: From April 2014 to March 2015, coronary angiograms of 102 patients less than 40 years of age with a definitive diagnosis of ischemic heart disease were studied. Traditional risk factors of atherosclerosis were documented. Mode of presentation and symptoms were recorded along with angiographic findings of coronary artery disease severity, degree of coronary involvement, culprit vessel, lesion morphology, coronary dominance, coronary ectasia and left ventricular systolic function. Results: Mean age was 36.4 ± 4.1 years and 91% were male. Overall, left ventricular systolic function were fairly preserved (82%). 52% patients had single vessel CAD, 25% had double vessel while 19% had triple vessel coronary artery disease. Four patients had no luminal stenosis on coronary angiogram. LAD was the culprit vessel in 58.8%, RCA in 24.5% and left circumflex artery in 16.7% cases. More than 82% culprit lesions were severe or critical. 58% lesions were morphologically complex B2/C type while only 42% lesions were type A/B1. Coronary ectasia was seen in nearly 25% cases and all had ACS presentation. Right dominance was more common than left (57.8% vs 37.3%) while only 4.9% cases had dual posterior septal supply. Conclusion: Premature CAD in our population is acutely symptomatic, severe, complex (B2/C), single vessel disease. (author)

  2. Fully automatic algorithm for the analysis of vessels in the angiographic image of the eye fundus

    Directory of Open Access Journals (Sweden)

    Koprowski Robert

    2012-06-01

    Full Text Available Abstract Background The available scientific literature contains descriptions of manual, semi-automated and automated methods for analysing angiographic images. The presented algorithms segment vessels calculating their tortuosity or number in a given area. We describe a statistical analysis of the inclination of the vessels in the fundus as related to their distance from the center of the optic disc. Methods The paper presents an automated method for analysing vessels which are found in angiographic images of the eye using a Matlab implemented algorithm. It performs filtration and convolution operations with suggested masks. The result is an image containing information on the location of vessels and their inclination angle in relation to the center of the optic disc. This is a new approach to the analysis of vessels whose usefulness has been confirmed in the diagnosis of hypertension. Results The proposed algorithm analyzed and processed the images of the eye fundus using a classifier in the form of decision trees. It enabled the proper classification of healthy patients and those with hypertension. The result is a very good separation of healthy subjects from the hypertensive ones: sensitivity - 83%, specificity - 100%, accuracy - 96%. This confirms a practical usefulness of the proposed method. Conclusions This paper presents an algorithm for the automatic analysis of morphological parameters of the fundus vessels. Such an analysis is performed during fluorescein angiography of the eye. The presented algorithm automatically calculates the global statistical features connected with both tortuosity of vessels and their total area or their number.

  3. Sub-clinical assessment of atopic dermatitis severity using angiographic optical coherence tomography

    Science.gov (United States)

    Byers, Robert A.; Maiti, Raman; Danby, Simon G.; Pang, Elaine J.; Mitchell, Bethany; Carré, Matt J.; Lewis, Roger; Cork, Michael J.; Matcher, Stephen J.

    2018-01-01

    Measurement of sub-clinical atopic dermatitis (AD) is important for determining how long therapies should be continued after clinical clearance of visible AD lesions. An important biomarker of sub-clinical AD is epidermal hypertrophy, the structural measures of which often make optical coherence tomography (OCT) challenging due to the lack of a clearly delineated dermal-epidermal junction in AD patients. Alternatively, angiographic OCT measurements of vascular depth and morphology may represent a robust biomarker for quantifying the severity of clinical and sub-clinical AD. To investigate this, angiographic data sets were acquired from 32 patients with a range of AD severities. Deeper vascular layers within skin were found to correlate with increasing clinical severity. Furthermore, for AD patients exhibiting no clinical symptoms, the superficial plexus depth was found to be significantly deeper than healthy patients at both the elbow (p = 0.04) and knee (p<0.001), suggesting that sub-clinical changes in severity can be detected. Furthermore, the morphology of vessels appeared altered in patients with severe AD, with significantly different vessel diameter, length, density and fractal dimension. These metrics provide valuable insight into the sub-clinical severity of the condition, allowing the effects of treatments to be monitored past the point of clinical remission. PMID:29675335

  4. Angiographic embolization in the treatment of intrahepatic arterial bleeding in patients with blunt abdominal trauma.

    Science.gov (United States)

    Kong, Ya-Lin; Zhang, Hong-Yi; He, Xiao-Jun; Zhao, Gang; Liu, Cheng-Li; Xiao, Mei; Zhen, Yu-Ying

    2014-04-01

    Angiographic embolization (AE) as an adjunct non-operative treatment of intrahepatic arterial bleeding has been widely used. The present study aimed to evaluate the efficacy of selective AE in patients with hepatic trauma. Seventy patients with intrahepatic arterial bleeding after blunt abdominal trauma who had undergone selective AE in 10 years at this institution were retrospectively reviewed. The criteria for selective AE included active extravasation on contrast-enhanced CT, an episode of hypotension or a decrease in hemoglobin level during the non-operative treatment. The data of the patients included demographics, grade of liver injuries, mechanism of blunt abdominal trauma, associated intra-abdominal injuries, indications for AE, angiographic findings, type of AE, and AE-related hepatobiliary complications. In the 70 patients, 32 (45.71%) had high-grade liver injuries. Extravazation during the early arterial phase mainly involved the right hepatic segments. Thirteen (18.57%) patients underwent embolization of intrahepatic branches and the extrahepatic trunk and these patients all developed AE-related hepatobiliary complications. In 19 patients with AE-related complications, 14 received minimally invasive treatment and recovered without severe sequelae. AE is an adjunct treatment for liver injuries. Selective and/or super-selective AE should be advocated to decrease the incidence and severity of AE-related hepatobiliary complications.

  5. The availability of appropriately fitting personal protective aprons and jackets for angiographic and interventional radiology personnel

    International Nuclear Information System (INIS)

    Cremen, S.A.; McNulty, J.P.

    2014-01-01

    Purpose: This study explored the availability of personal protective equipment, lead or lead-free aprons or jackets, in angiographic and interventional radiology suites in the Republic of Ireland with a focus on the sizes available, appropriateness of fit and purchasing practices. Methods: All centres providing an angiographic or interventional radiology service in the Republic of Ireland were invited to participate with data being collected by means of a postal questionnaire exploring the above issues. Results: The mean number of aprons or jackets available across the centres who responded to the survey was 18.4 with the majority of these, 72%, being medium or large in size. Clinical specialists in three centres identified that there were insufficient aprons or jackets sized extra small or extra large within their departments and only one centre had a purchasing policy in place where individual staff were assigned a personal apron or jacket. Conclusion: Ill-fitting aprons or jackets will reduce the shielding provided to certain body regions by personal protective equipment. The use of over-sized aprons or jackets by staff is of particular concern based on the potential for inadvertent exposure to tissues where cancers may potentially be induced due to poor armhole fit. It is important to carefully consider purchasing practices and range of personal protective equipment sizes available in order to ensure that all staff receive the greatest possible protection from occupational radiation exposure

  6. Learning from uncertain curves

    DEFF Research Database (Denmark)

    Mallasto, Anton; Feragen, Aasa

    2017-01-01

    We introduce a novel framework for statistical analysis of populations of nondegenerate Gaussian processes (GPs), which are natural representations of uncertain curves. This allows inherent variation or uncertainty in function-valued data to be properly incorporated in the population analysis. Us...

  7. Power Curve Measurements

    DEFF Research Database (Denmark)

    Federici, Paolo; Kock, Carsten Weber

    This report describes the power curve measurements performed with a nacelle LIDAR on a given wind turbine in a wind farm and during a chosen measurement period. The measurements and analysis are carried out in accordance to the guidelines in the procedure “DTU Wind Energy-E-0019” [1]. The reporting...

  8. Power Curve Measurements, FGW

    DEFF Research Database (Denmark)

    Vesth, Allan; Kock, Carsten Weber

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine....

  9. Power Curve Measurements

    DEFF Research Database (Denmark)

    Federici, Paolo; Vesth, Allan

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine....

  10. Power Curve Measurements

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Gómez Arranz, Paula

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine...

  11. Carbon Lorenz Curves

    NARCIS (Netherlands)

    Groot, L.F.M.|info:eu-repo/dai/nl/073642398

    2008-01-01

    The purpose of this paper is twofold. First, it exhibits that standard tools in the measurement of income inequality, such as the Lorenz curve and the Gini-index, can successfully be applied to the issues of inequality measurement of carbon emissions and the equity of abatement policies across

  12. The Axial Curve Rotator.

    Science.gov (United States)

    Hunter, Walter M.

    This document contains detailed directions for constructing a device that mechanically produces the three-dimensional shape resulting from the rotation of any algebraic line or curve around either axis on the coordinate plant. The device was developed in response to student difficulty in visualizing, and thus grasping the mathematical principles…

  13. Nacelle lidar power curve

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report describes the power curve measurements performed with a nacelle LIDAR on a given wind turbine in a wind farm and during a chosen measurement period. The measurements and analysis are carried out in accordance to the guidelines in the procedure “DTU Wind Energy-E-0019” [1]. The reporting...

  14. Power curve report

    DEFF Research Database (Denmark)

    Vesth, Allan; Kock, Carsten Weber

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...

  15. Textbook Factor Demand Curves.

    Science.gov (United States)

    Davis, Joe C.

    1994-01-01

    Maintains that teachers and textbook graphics follow the same basic pattern in illustrating changes in demand curves when product prices increase. Asserts that the use of computer graphics will enable teachers to be more precise in their graphic presentation of price elasticity. (CFR)

  16. ECM using Edwards curves

    NARCIS (Netherlands)

    Bernstein, D.J.; Birkner, P.; Lange, T.; Peters, C.P.

    2013-01-01

    This paper introduces EECM-MPFQ, a fast implementation of the elliptic-curve method of factoring integers. EECM-MPFQ uses fewer modular multiplications than the well-known GMP-ECM software, takes less time than GMP-ECM, and finds more primes than GMP-ECM. The main improvements above the

  17. Power Curve Measurements FGW

    DEFF Research Database (Denmark)

    Federici, Paolo; Kock, Carsten Weber

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine...

  18. Recurrent bleeding after arterial embolization in patients with hemoptysis : Comparison of angiographic findings and relapsing period

    International Nuclear Information System (INIS)

    Park, Sung Keun; Choi, Seok Jin; Choi, Gi Bok; Kim, Hae Yeon; Park, Auh Whan; Juhn, Jae Ryang; Cha, Seong Sook

    2001-01-01

    To describe the angiographic findings of patients with recurrent hemoptysis after bronchial artery embolization (BAE) according to the point at which relapse occurred. From 125 patients who underwent BAE due to hemoptysis between 1996 and 2000, we selected 18 of 23 who underwent additional BAE due to recurrent bleeding after initial BAE. Depending on the point at which relapse occurred, they were divided into two groups (I and ll, according to whether additional BAE was performed within two weeks of initial BAE or more than two weeks after this) We retrospectively compared the two groups in terms of angiographic findings, number of embolized arteries, and character of feeding arteries at initial and additional BAE. Nine patients in group I (additional BAE: n=10) and nine in group ll (additional BAE: n=13) were admitted for recurrent hemoptysis within two weeks of initial BAE and more than two weeks after this, respectively. In group I (n=29) and ll(n=31), angiography demonstrated two direct and 27 indirect, and two direct and 29 indirect signs of hemorrhage, respectiveIy. No statistically significant differences were observed (x 2 =0.005, ρ=0.945). Among the embolized feeder ressels in group I (n=30) there were 20 bronchial artery and 10 non bronchial systemic collaterals, while for group ll (n=35), the corresponding totals were 21 and 14. Again, no statistically significant differences were encountered(x 2 =0.308; ρ=0.579). In group I, feeders were newly developed in one case(10%), previously embolized in five(50%), and missed in four(40%), while in group two the corresponding figures were none, twelve(92.3%), and one(7.7%) No significant differences were noted, though the incidence of previously embolized feeders in Group ll was very high (x 2 =5.383, ρ=0.068). Among patients in whom hemoptysis after BAE recurred at different times, the angiographic findings and number of embolized arteries were not significantly different, but differences in the nature of the

  19. Codes and curves

    CERN Document Server

    Walker, Judy L

    2000-01-01

    When information is transmitted, errors are likely to occur. Coding theory examines efficient ways of packaging data so that these errors can be detected, or even corrected. The traditional tools of coding theory have come from combinatorics and group theory. Lately, however, coding theorists have added techniques from algebraic geometry to their toolboxes. In particular, by re-interpreting the Reed-Solomon codes, one can see how to define new codes based on divisors on algebraic curves. For instance, using modular curves over finite fields, Tsfasman, Vladut, and Zink showed that one can define a sequence of codes with asymptotically better parameters than any previously known codes. This monograph is based on a series of lectures the author gave as part of the IAS/PCMI program on arithmetic algebraic geometry. Here, the reader is introduced to the exciting field of algebraic geometric coding theory. Presenting the material in the same conversational tone of the lectures, the author covers linear codes, inclu...

  20. Carbon Lorenz Curves

    Energy Technology Data Exchange (ETDEWEB)

    Groot, L. [Utrecht University, Utrecht School of Economics, Janskerkhof 12, 3512 BL Utrecht (Netherlands)

    2008-11-15

    The purpose of this paper is twofold. First, it exhibits that standard tools in the measurement of income inequality, such as the Lorenz curve and the Gini-index, can successfully be applied to the issues of inequality measurement of carbon emissions and the equity of abatement policies across countries. These tools allow policy-makers and the general public to grasp at a single glance the impact of conventional distribution rules such as equal caps or grandfathering, or more sophisticated ones, on the distribution of greenhouse gas emissions. Second, using the Samuelson rule for the optimal provision of a public good, the Pareto-optimal distribution of carbon emissions is compared with the distribution that follows if countries follow Nash-Cournot abatement strategies. It is shown that the Pareto-optimal distribution under the Samuelson rule can be approximated by the equal cap division, represented by the diagonal in the Lorenz curve diagram.

  1. Evaluation of indicator dilution process in X-ray angiographic images deteriorated by factors of technical origin

    International Nuclear Information System (INIS)

    Dernalowicz, J.; Goszczynska, H.; Mazur, P.

    1996-01-01

    Different sources of error in X-rays angiographic images have been discussed. Some kind of error which considerably influences densitometric analysis of time sequences of images - the fluctuation of image intensity during coronarography screening - has been emphasized and discussed in details. Three practical solutions of how to correct (compensate) such error have been proposed and described. (author)

  2. The predictive value of angiographic results for the outcome of percutaneous transluminal angioplasty in stenosed femoral bypass grafts

    International Nuclear Information System (INIS)

    Spijkerboer, Anje M.; Beek, Frederik J. A.; Graaf, Yolanda van der; Eikelboom, Bert C.; Mali, Willem P. T. M.

    1997-01-01

    Purpose. To assess the predictive value of immediate angiographic results after percutaneous transluminal angioplasty (PTA) for stenoses in femoral bypass grafts using duplex ultrasound (DUS) criteria. Methods. A 1-year follow-up with DUS was performed in 38 patients with 50 stenoses in 41 grafts, treated with PTA for a graft stenosis. The indication for PTA according to DUS criteria was a severe stenosis in 43 lesions, and a moderate stenosis in 7 lesions. In the moderate stenosis group 3 patients showed claudication and 1 patient had a nonhealing ulcer. For the purposes of statistical evaluation, primary patency was considered present if the graft was not occluded. The graft was considered to have failed when it was found to be occluded on DUS, or when secondary interventions (surgery, repeat PTA) were performed. Results. After 1 year the cumulative primary patency rate was 44$ [95% confidence interval (CI) 27.8-59.8]. Stenoses with initially good angiographic results after PTA (<30% residual stenosis) were 2.9 times more likely to be patent at 1 year than stenoses with initially poor or moderate angiographic results (hazard ratio 2.9, 95% CI 1.3-6.4,p=0.007). Conclusion. A poor or moderate angiographic result immediately following PTA was prognostic for poor long-term results and may indicate a requirement for earlier surgical intervention

  3. Stenting for symptomatic vertebral artery stenosis associated with bilateral carotid rate mirabile: The long-term clinical and angiographic outcome

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Jang Hyun; Kim, Byung Moon [Dept. of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2015-06-15

    Symptomatic vertebral artery (VA) stenosis associated with bilateral carotid rate mirabile (CRM) has not been reported. We report the long-term clinical and angiographic outcome after stenting for symptomatic VA stenosis in the patient with bilateral CRM. This report is the first case that symptomatic VA stenosis associated with bilateral CRM was treated with stenting.

  4. Stenting for symptomatic vertebral artery stenosis associated with bilateral carotid rate mirabile: The long-term clinical and angiographic outcome

    International Nuclear Information System (INIS)

    Baek, Jang Hyun; Kim, Byung Moon

    2015-01-01

    Symptomatic vertebral artery (VA) stenosis associated with bilateral carotid rate mirabile (CRM) has not been reported. We report the long-term clinical and angiographic outcome after stenting for symptomatic VA stenosis in the patient with bilateral CRM. This report is the first case that symptomatic VA stenosis associated with bilateral CRM was treated with stenting.

  5. Usefulness of angiographic embolization endoscopic metallic clip placement in patient with non-variceal upper gastrointestinal bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Min Jae; Hwang, Cheol Mog; Kim, Ho Jun; Cho, Young Jun; Bae, Seok Hwan [Dept. of Radiology, Konyang University Hospital, Daejeon (Korea, Republic of); Shin, Byung Seok; Ohm, Joon Young [Dept. of Radiology, Chungnam National University College of Medicine, Daejeon (Korea, Republic of); Kang, Chae Hoon [Dept. of Radiology, Inje University College of Medicine, Pusan Paik Hospital, Busan (Korea, Republic of)

    2013-08-15

    The aim of this study is to assess the usefulness of angiographic embolization after endoscopic metallic clip placement around the edge of non-variceal upper gastrointestinal bleeding ulcers. We have chosen 41 patients (mean age, 65.2 years) with acute bleeding ulcers (22 gastric ulcers, 16 duodenal ulcers, 3 malignant ulcers) between January 2010 and December 2012. We inserted metallic clips during the routine endoscopic treatments of the bleeding ulcers. Subsequent transcatheter arterial embolization was performed within 2 hours. We analyzed the angiographic positive rates, angiographic success rates and clinical success rates. Among the 41 patients during the angiography, 19 patients (46%) demonstrated active bleeding points. Both groups underwent embolization using microcoils, N-butyl-cyano-acrylate (NBCA), microcoils with NBCA or gelfoam particle. There are no statistically significant differences between these two groups according to which embolic materials are being used. The bleeding was initially stopped in all patients, except the two who experienced technical failures. Seven patients experienced repeated episodes of bleeding within two weeks. Among them, 4 patients were successful re-embolized. Another 3 patients underwent gastrectomy. Overall, clinical success was achieved in 36 of 41 (87.8%) patients. The endoscopic metallic clip placement was helpful to locate the correct target vessels for the angiographic embolization. In conclusion, this technique reduced re-bleeding rates, especially in patients who do not show active bleeding points.

  6. C-reactive protein and angiographic characteristics of stable and unstable coronary artery disease : Data from the prospective PREVEND cohort

    NARCIS (Netherlands)

    Geluk, C.A.; Post, W.J.; Hillege, H.L.; Tio, R.A.; Tijssen, J.G.; van Dijk, R.B.; Dijk, Willem; Bakker, S.J.; de Jong, P.E.; van Gilst, W.H.; Zijlstra, F.

    Aims: High sensitive-C-reactive protein (hs-CRP) is associated with coronary risk, which may be explained by an association with (unstable) coronary artery disease (CAD). Until now, histopathological and angiographic studies have failed to consistently demonstrate a strong relationship. However,

  7. Usefulness of angiographic embolization endoscopic metallic clip placement in patient with non-variceal upper gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Yoon, Min Jae; Hwang, Cheol Mog; Kim, Ho Jun; Cho, Young Jun; Bae, Seok Hwan; Shin, Byung Seok; Ohm, Joon Young; Kang, Chae Hoon

    2013-01-01

    The aim of this study is to assess the usefulness of angiographic embolization after endoscopic metallic clip placement around the edge of non-variceal upper gastrointestinal bleeding ulcers. We have chosen 41 patients (mean age, 65.2 years) with acute bleeding ulcers (22 gastric ulcers, 16 duodenal ulcers, 3 malignant ulcers) between January 2010 and December 2012. We inserted metallic clips during the routine endoscopic treatments of the bleeding ulcers. Subsequent transcatheter arterial embolization was performed within 2 hours. We analyzed the angiographic positive rates, angiographic success rates and clinical success rates. Among the 41 patients during the angiography, 19 patients (46%) demonstrated active bleeding points. Both groups underwent embolization using microcoils, N-butyl-cyano-acrylate (NBCA), microcoils with NBCA or gelfoam particle. There are no statistically significant differences between these two groups according to which embolic materials are being used. The bleeding was initially stopped in all patients, except the two who experienced technical failures. Seven patients experienced repeated episodes of bleeding within two weeks. Among them, 4 patients were successful re-embolized. Another 3 patients underwent gastrectomy. Overall, clinical success was achieved in 36 of 41 (87.8%) patients. The endoscopic metallic clip placement was helpful to locate the correct target vessels for the angiographic embolization. In conclusion, this technique reduced re-bleeding rates, especially in patients who do not show active bleeding points.

  8. An angiographic study of left- and right-ventricular function in patients with alcoholic heart and dilatation cardiomyopathy

    International Nuclear Information System (INIS)

    Savchenko, A.P.; Samko, A.N.; Smetnev, A.S.; Grudtsyn, G.V.

    1986-01-01

    An angiographic study of left- and right-ventricular function in 57 patients with alcoholic heart and dilatation cardiomyopathy demonstrated preclinical disorders of left-ventricular myocardial contractility and more marked right-ventricular changes in patients with second-stage chronic alcoholism. In cases of dilatation cardiomyopathy, left-ventricular dysfunction was predominant, while right-venricular changes were less pronouced

  9. Long-term Luminal Renarrowing After Successful Elective Coronary Angioplasty of Total Occlusions : A Quantitative Angiographic Analysis

    NARCIS (Netherlands)

    A.G. Violaris (Andonis); R. Melkert (Rein); P.W.J.C. Serruys (Patrick)

    1995-01-01

    textabstractBackground The long-term angiographic outcome after successful dilatation of coronary occlusions remains unclear. The objective of this study was to examine long-term restenosis after successful balloon dilatation of coronary occlusions at a predetermined time interval with quantitative

  10. Dynamics of curved fronts

    CERN Document Server

    Pelce, Pierre

    1989-01-01

    In recent years, much progress has been made in the understanding of interface dynamics of various systems: hydrodynamics, crystal growth, chemical reactions, and combustion. Dynamics of Curved Fronts is an important contribution to this field and will be an indispensable reference work for researchers and graduate students in physics, applied mathematics, and chemical engineering. The book consist of a 100 page introduction by the editor and 33 seminal articles from various disciplines.

  11. International Wage Curves

    OpenAIRE

    David G. Blanchflower; Andrew J. Oswald

    1992-01-01

    The paper provides evidence for the existence of a negatively sloped locus linking the level of pay to the rate of regional (or industry) unemployment. This "wage curve" is estimated using microeconomic data for Britain, the US, Canada, Korea, Austria, Italy, Holland, Switzerland, Norway, and Germany, The average unemployment elasticity of pay is approximately -0.1. The paper sets out a multi-region efficiency wage model and argues that its predictions are consistent with the data.

  12. Anatomical curve identification

    Science.gov (United States)

    Bowman, Adrian W.; Katina, Stanislav; Smith, Joanna; Brown, Denise

    2015-01-01

    Methods for capturing images in three dimensions are now widely available, with stereo-photogrammetry and laser scanning being two common approaches. In anatomical studies, a number of landmarks are usually identified manually from each of these images and these form the basis of subsequent statistical analysis. However, landmarks express only a very small proportion of the information available from the images. Anatomically defined curves have the advantage of providing a much richer expression of shape. This is explored in the context of identifying the boundary of breasts from an image of the female torso and the boundary of the lips from a facial image. The curves of interest are characterised by ridges or valleys. Key issues in estimation are the ability to navigate across the anatomical surface in three-dimensions, the ability to recognise the relevant boundary and the need to assess the evidence for the presence of the surface feature of interest. The first issue is addressed by the use of principal curves, as an extension of principal components, the second by suitable assessment of curvature and the third by change-point detection. P-spline smoothing is used as an integral part of the methods but adaptations are made to the specific anatomical features of interest. After estimation of the boundary curves, the intermediate surfaces of the anatomical feature of interest can be characterised by surface interpolation. This allows shape variation to be explored using standard methods such as principal components. These tools are applied to a collection of images of women where one breast has been reconstructed after mastectomy and where interest lies in shape differences between the reconstructed and unreconstructed breasts. They are also applied to a collection of lip images where possible differences in shape between males and females are of interest. PMID:26041943

  13. Estimating Corporate Yield Curves

    OpenAIRE

    Antionio Diaz; Frank Skinner

    2001-01-01

    This paper represents the first study of retail deposit spreads of UK financial institutions using stochastic interest rate modelling and the market comparable approach. By replicating quoted fixed deposit rates using the Black Derman and Toy (1990) stochastic interest rate model, we find that the spread between fixed and variable rates of interest can be modeled (and priced) using an interest rate swap analogy. We also find that we can estimate an individual bank deposit yield curve as a spr...

  14. LCC: Light Curves Classifier

    Science.gov (United States)

    Vo, Martin

    2017-08-01

    Light Curves Classifier uses data mining and machine learning to obtain and classify desired objects. This task can be accomplished by attributes of light curves or any time series, including shapes, histograms, or variograms, or by other available information about the inspected objects, such as color indices, temperatures, and abundances. After specifying features which describe the objects to be searched, the software trains on a given training sample, and can then be used for unsupervised clustering for visualizing the natural separation of the sample. The package can be also used for automatic tuning parameters of used methods (for example, number of hidden neurons or binning ratio). Trained classifiers can be used for filtering outputs from astronomical databases or data stored locally. The Light Curve Classifier can also be used for simple downloading of light curves and all available information of queried stars. It natively can connect to OgleII, OgleIII, ASAS, CoRoT, Kepler, Catalina and MACHO, and new connectors or descriptors can be implemented. In addition to direct usage of the package and command line UI, the program can be used through a web interface. Users can create jobs for ”training” methods on given objects, querying databases and filtering outputs by trained filters. Preimplemented descriptors, classifier and connectors can be picked by simple clicks and their parameters can be tuned by giving ranges of these values. All combinations are then calculated and the best one is used for creating the filter. Natural separation of the data can be visualized by unsupervised clustering.

  15. Gastroesophageal Variceal Filling and Drainage Pathways: An Angiographic Description of Afferent and Efferent Venous Anatomic Patterns

    Directory of Open Access Journals (Sweden)

    Ron C Gaba

    2015-01-01

    Full Text Available Varices commonly occur in liver cirrhosis patients and are classified as esophageal (EV, gastroesophageal (GEV, or isolated gastric (IGV varices. These vessels may be supplied and drained by several different afferent and efferent pathways. A working knowledge of variceal anatomy is imperative for Interventional Radiologists performing transjugular intrahepatic portosystemic shunt and embolization/obliteration procedures. This pictorial essay characterizes the angiographic anatomy of varices in terms of type and frequency of venous filling and drainage, showing that different varices have distinct vascular anatomy. EVs typically show left gastric vein filling and “uphill” drainage, and GEVs and IGVs exhibit additional posterior/short gastric vein contribution and “downhill” outflow. An understanding of these variceal filling and drainage pathways can facilitate successful portal decompression and embolization/obliteration procedures.

  16. Right ventricular ejection fraction - comparison of various angiographic and radionuclide approaches

    International Nuclear Information System (INIS)

    Schicha, H.; Tebbe, U.; Voth, E.; Sciagra, R.; Schultz, W.; Neuhaus, G.; Goettingen Univ.

    1987-01-01

    In 21 patients with various heart diseases RVEF was measured angiographically and by radionuclide ventriculography. Using biplane angiocardiography evaluation was performed by 7 different methods (Simpson's rule, Dogde, Arcilla, Ferlinz, Duebel). Using equilibrium RNV, evaluation was performed by 9 modifications of analysis. Problems were evident to separate the right atrium from the ventricle and to define the site of the pulmonary valve. The results show that when using the various methods of angiography considerable variations of the absolute volumes occur, but least so with RVEF. When using RNV with one single enddiastolic ROI, the RVEF was much too low. By means of the enddiastolic/endsystolic Double-ROI-method a good agreement with angiography was found, with correlation coefficients up to r=0.85. There was only a minor effect of background correction. (orig.) [de

  17. The anterior choroidal artery syndrome. Pt. 2. CT and/or MR in angiographically verified cases

    International Nuclear Information System (INIS)

    Takahashi, S.; Ishii, K.; Matsumoto, K.; Higano, S.; Ishibashi, T.; Suzuki, M.; Sakamoto, K.

    1994-01-01

    We reviewed 12 cases of infarcts in the territory of the anterior choroidal artery (AChA) on CT and/or MRI. In each case vascular occlusion in the region was verified angiographically. Although the extent of the lesion on CT/MR images was variable, all were located on the axial images within an arcuate zone between the striatium anterolaterally and the thalamus posteromedially. The distribution of the lesions on mutiplanar MRI conformed well to the territory of the AChA demonstrated microangiographically. The variability of the extent of the infarcts may be explained by variations in the degree of occlusive changes in the AChA or the development of collateral circulation through anastomoses between the AChA and the posterior communicating and posterior cerebral arteries. The extent of the lesion appeared to be closely related to the degree of neurological deficit. (orig.)

  18. Prognostic value of Angiographic Perfusion Score (APS) following percutaneous interventions in acute coronary syndromes.

    Science.gov (United States)

    Narain, V S; Fischer, L; Puri, A; Sethi, R; Dwivedi, S K

    2013-01-01

    Identifying reperfusion and predicting post procedure risk is important following Percutaneous Coronary Interventions (PCI). An Angiographic Perfusion Score (APS) combining TIMI flow (TFG) and myocardial perfusion (TMPG) grades before and after PCI can accurately measure both epicardial and myocardial perfusion and predict Major Adverse Cardiac Events (MACE). APS was calculated in 226 (88 ST elevation Myocardial Infarction (STEMI) and 138 Non STEMI) patients. Maximum score being 12, reperfusion was defined as failed: 0-3, partial: 4-9, and full APS: 10-12. Thirty day MACE were observed. APS identified reperfusion significantly more than TMPG alone (STEMI: 50.6% vs 11.8% (p APS group (1.8% vs 22.5%) (p APS detects more low risk reperfused patients, post PCI. Copyright © 2012. Published by Elsevier B.V.

  19. Cerebral Angiographic Findings of Cosmetic Facial Filler-related Ophthalmic and Retinal Artery Occlusion.

    Science.gov (United States)

    Kim, Yong-Kyu; Jung, Cheolkyu; Woo, Se Joon; Park, Kyu Hyung

    2015-12-01

    Cosmetic facial filler-related ophthalmic artery occlusion is rare but is a devastating complication, while the exact pathophysiology is still elusive. Cerebral angiography provides more detailed information on blood flow of ophthalmic artery as well as surrounding orbital area which cannot be covered by fundus fluorescein angiography. This study aimed to evaluate cerebral angiographic features of cosmetic facial filler-related ophthalmic artery occlusion patients. We retrospectively reviewed cerebral angiography of 7 patients (4 hyaluronic acid [HA] and 3 autologous fat-injected cases) showing ophthalmic artery and its branches occlusion after cosmetic facial filler injections, and underwent intra-arterial thrombolysis. On selective ophthalmic artery angiograms, all fat-injected patients showed a large filling defect on the proximal ophthalmic artery, whereas the HA-injected patients showed occlusion of the distal branches of the ophthalmic artery. Three HA-injected patients revealed diminished distal runoff of the internal maxillary and facial arteries, which clinically corresponded with skin necrosis. However, all fat-injected patients and one HA-injected patient who were immediately treated with subcutaneous hyaluronidase injection showed preserved distal runoff of the internal maxillary and facial arteries and mild skin problems. The size difference between injected materials seems to be associated with different angiographic findings. Autologous fat is more prone to obstruct proximal part of ophthalmic artery, whereas HA obstructs distal branches. In addition, hydrophilic and volume-expansion property of HA might exacerbate blood flow on injected area, which is also related to skin necrosis. Intra-arterial thrombolysis has a limited role in reconstituting blood flow or regaining vision in cosmetic facial filler-associated ophthalmic artery occlusions.

  20. Pelvic Arterial Anatomy Relevant to Prostatic Artery Embolisation and Proposal for Angiographic Classification

    Energy Technology Data Exchange (ETDEWEB)

    Assis, André Moreira de, E-mail: andre.maa@gmail.com; Moreira, Airton Mota, E-mail: motamoreira@gmail.com; Paula Rodrigues, Vanessa Cristina de, E-mail: vanessapaular@yahoo.com.br [University of Sao Paulo Medical School, Interventional Radiology and Endovascular Surgery Department, Radiology Institute (Brazil); Harward, Sardis Honoria, E-mail: sardis.harward@merit.com [The Dartmouth Center for Health Care Delivery Science (United States); Antunes, Alberto Azoubel, E-mail: antunesuro@uol.com.br; Srougi, Miguel, E-mail: srougi@usp.br [University of Sao Paulo Medical School, Urology Department (Brazil); Carnevale, Francisco Cesar, E-mail: fcarnevale@uol.com.br [University of Sao Paulo Medical School, Interventional Radiology and Endovascular Surgery Department, Radiology Institute (Brazil)

    2015-08-15

    PurposeTo describe and categorize the angiographic findings regarding prostatic vascularization, propose an anatomic classification, and discuss its implications for the PAE procedure.MethodsAngiographic findings from 143 PAE procedures were reviewed retrospectively, and the origin of the inferior vesical artery (IVA) was classified into five subtypes as follows: type I: IVA originating from the anterior division of the internal iliac artery (IIA), from a common trunk with the superior vesical artery (SVA); type II: IVA originating from the anterior division of the IIA, inferior to the SVA origin; type III: IVA originating from the obturator artery; type IV: IVA originating from the internal pudendal artery; and type V: less common origins of the IVA. Incidences were calculated by percentage.ResultsTwo hundred eighty-six pelvic sides (n = 286) were analyzed, and 267 (93.3 %) were classified into I–IV types. Among them, the most common origin was type IV (n = 89, 31.1 %), followed by type I (n = 82, 28.7 %), type III (n = 54, 18.9 %), and type II (n = 42, 14.7 %). Type V anatomy was seen in 16 cases (5.6 %). Double vascularization, defined as two independent prostatic branches in one pelvic side, was seen in 23 cases (8.0 %).ConclusionsDespite the large number of possible anatomical variations of male pelvis, four main patterns corresponded to almost 95 % of the cases. Evaluation of anatomy in a systematic fashion, following a standard classification, will make PAE a faster, safer, and more effective procedure.

  1. Angiographic Characteristics of Symptomatic Recurrent Disease After Infrainguinal Percutaneous Transluminal Angioplasty

    International Nuclear Information System (INIS)

    Soeder, Heini K.; Manninen, Hannu I.; Matsi, Pekka J.

    1999-01-01

    Purpose: To evaluate the angiographic patterns of clinically manifest recurrent disease after infrainguinal percutaneous transluminal angioplasty (PTA) of stenoses and total occlusions. Methods: Among 326 infrainguinal PTAs on 263 consecutive patients, selective angiography was performed on 61 limbs of 52 patients 1-60 months after the primary intervention because of clinically suspected recurrent disease. Lesion-specific and patient-related factors were analyzed for 75 angiographically confirmed recurrent lesions in 57 limbs of 48 patients. Results: Recurrent disease was more frequently a stenosis when the original target lesion was a stenosis (92%, 44/48) than when the original lesion was a total occlusion (59%, 16/27; p < 0.001). When the original target lesion was a stenosis, the total length of the recurrent disease was longer than that of the original lesion [3.9 ± 3.9 cm (mean ± standard deviation) vs 2.8 ± 2.7 cm; p= 0.03], while in the subgroup of original total occlusions the length of the recurrent lesion was shorter than that of the original occlusion (7.1 ± 5.0 cm vs 9.9 ± 6.9 cm; p0.02). Half the restenoses (22/44) extended beyond one or both ends of the original stenosis and 38% (6/16) of the reocclusions extended beyond the distal end of the original occlusion. Conclusions: The type of recurrent disease depends on the original lesion type and the restenotic lesion frequently extends beyond one or both ends of the original target lesion

  2. Intracranial infective aneurysms presenting with haemorrhage: An analysis of angiographic findings, management and outcome

    International Nuclear Information System (INIS)

    Venkatesh, Sudhakar K.; Phadke, Rajendra V.; Kalode, Ravi R.; Kumar, Sunil; Jain, Vijendra K.

    2000-01-01

    AIM: This study is an analysis of angiographic findings in 17 patients with infective aneurysms who presented with intracranial haemorrhage and reviews the management and outcome in the context of the existing literature. MATERIALS AND METHODS: A retrospective study of infective aneurysms in 17 patients was carried out. Cranial angiography was performed in all patients. The location, size and outline of aneurysms were analysed. Ten patients were managed conservatively and six patients underwent surgery for the ruptured infective aneurysms and were followed up for a period of 35.8 months and 23 months, respectively. RESULTS: Twenty-two aneurysms were identified (five unruptured) in 17 patients. Twenty aneurysms (90.9%) were distal in location and two (9.1%) proximal. Sixty percent were in the posterior circulation with 55% in the posterior cerebral artery (PCA) territory, 27.3% in the middle cerebral artery (MCA) territory and 9.1% in the anterior cerebral artery (ACA) territory. Fourteen aneurysms were small (3-5 mm) and eight were medium sized (6-9 mm). 72.7% of aneurysms had irregular outline and 27.3% regular outline. Out of the 10 ruptured aneurysms managed conservatively, eight resolved. One patient died, presumably due to rebleed, and one had infarction due to parent vessel thrombosis. Six aneurysms were surgically managed with good results. Of the five unruptured aneurysms one was surgically managed and the remaining four conservatively managed patients did not bleed during follow-up. CONCLUSION: Patients with ruptured infective aneurysms fared well with medical management and the outcome in this series is better than that reported in literature. Patients on conservative management, however, need closer monitoring with angiographic follow-up. Active management is required with enlarging or persisting aneurysms. Venkatesh, S.K. (2000)

  3. The angiographic findings of coronary arterial spasm (a report of 37 cases)

    International Nuclear Information System (INIS)

    Kuang Jianyi; Chen Jianhun; Du Zhimin; Li Xiangmin; Hu Chengheng

    2002-01-01

    Objective: The arterial spasm which often seen in the coronary angiography was considered as a result of the pathological spasm of the coronary artery or a complication of catheterization. The coronary arterial spasm is a considerable situation because it increases the danger of stenotic lesions in coronary artery, which should be managed immediately. Methods: In total 37 patients presented with coronary arterial spasm in the coronary angiography (Judkins method): 23 male and 14 female, aged 43-60 years (the 47 years in average). Spasms were relieved in all patients after the administration of glonoin. Results: Solitary spasm were the most common, the angiographic findings were long section (>10 mm) with stenosis of 50%-65% in left anterior descending artery (12 cases), or in the middle and near portion of the right coronary artery (5 cases), where the orifice of the branches were involved; severe stenosis of the orifice of the right coronary artery (3 cases); irregular, mild and local spasm in left anterior descending artery or circumflex (8 cases). And multiple spasm was observed in left anterior descending artery (4 cases) or in the right coronary artery (5 cases). In 19 cases, stenosis accompanying with spasm were revealed and local spasm were observed at the site of arterial sclerosis. Conclusion: The spasm owing to the catheterization doesn't result in chest discomfort and changes in EKG, while pathological spasm occurs in the population with high risk of coronary heart disease, which indicates the potential myocardial infraction. The angiographic findings helps differentiating the two situation

  4. Fast virtual functional assessment of intermediate coronary lesions using routine angiographic data and blood flow simulation in humans: comparison with pressure wire - fractional flow reserve.

    Science.gov (United States)

    Papafaklis, Michail I; Muramatsu, Takashi; Ishibashi, Yuki; Lakkas, Lampros S; Nakatani, Shimpei; Bourantas, Christos V; Ligthart, Jurgen; Onuma, Yoshinobu; Echavarria-Pinto, Mauro; Tsirka, Georgia; Kotsia, Anna; Nikas, Dimitrios N; Mogabgab, Owen; van Geuns, Robert-Jan; Naka, Katerina K; Fotiadis, Dimitrios I; Brilakis, Emmanouil S; Garcia-Garcia, Héctor M; Escaned, Javier; Zijlstra, Felix; Michalis, Lampros K; Serruys, Patrick W

    2014-09-01

    To develop a simplified approach of virtual functional assessment of coronary stenosis from routine angiographic data and test it against fractional flow reserve using a pressure wire (wire-FFR). Three-dimensional quantitative coronary angiography (3D-QCA) was performed in 139 vessels (120 patients) with intermediate lesions assessed by wire-FFR (reference standard: ≤0.80). The 3D-QCA models were processed with computational fluid dynamics (CFD) to calculate the lesion-specific pressure gradient (ΔP) and construct the ΔP-flow curve, from which the virtual functional assessment index (vFAI) was derived. The discriminatory power of vFAI for ischaemia- producing lesions was high (area under the receiver operator characteristic curve [AUC]: 92% [95% CI: 86-96%]). Diagnostic accuracy, sensitivity and specificity for the optimal vFAI cut-point (≤0.82) were 88%, 90% and 86%, respectively. Virtual-FAI demonstrated superior discrimination against 3D-QCA-derived % area stenosis (AUC: 78% [95% CI: 70- 84%]; p<0.0001 compared to vFAI). There was a close correlation (r=0.78, p<0.0001) and agreement of vFAI compared to wire-FFR (mean difference: -0.0039±0.085, p=0.59). We developed a fast and simple CFD-powered virtual haemodynamic assessment model using only routine angiography and without requiring any invasive physiology measurements/hyperaemia induction. Virtual-FAI showed a high diagnostic performance and incremental value to QCA for predicting wire-FFR; this "less invasive" approach could have important implications for patient management and cost.

  5. Uniformization of elliptic curves

    OpenAIRE

    Ülkem, Özge; Ulkem, Ozge

    2015-01-01

    Every elliptic curve E defined over C is analytically isomorphic to C*=qZ for some q ∊ C*. Similarly, Tate has shown that if E is defined over a p-adic field K, then E is analytically isomorphic to K*=qZ for some q ∊ K . Further the isomorphism E(K) ≅ K*/qZ respects the action of the Galois group GK/K, where K is the algebraic closure of K. I will explain the construction of this isomorphism.

  6. Roc curves for continuous data

    CERN Document Server

    Krzanowski, Wojtek J

    2009-01-01

    Since ROC curves have become ubiquitous in many application areas, the various advances have been scattered across disparate articles and texts. ROC Curves for Continuous Data is the first book solely devoted to the subject, bringing together all the relevant material to provide a clear understanding of how to analyze ROC curves.The fundamental theory of ROC curvesThe book first discusses the relationship between the ROC curve and numerous performance measures and then extends the theory into practice by describing how ROC curves are estimated. Further building on the theory, the authors prese

  7. Curved Josephson junction

    International Nuclear Information System (INIS)

    Dobrowolski, Tomasz

    2012-01-01

    The constant curvature one and quasi-one dimensional Josephson junction is considered. On the base of Maxwell equations, the sine–Gordon equation that describes an influence of curvature on the kink motion was obtained. It is showed that the method of geometrical reduction of the sine–Gordon model from three to lower dimensional manifold leads to an identical form of the sine–Gordon equation. - Highlights: ► The research on dynamics of the phase in a curved Josephson junction is performed. ► The geometrical reduction is applied to the sine–Gordon model. ► The results of geometrical reduction and the fundamental research are compared.

  8. Curved-Duct

    Directory of Open Access Journals (Sweden)

    Je Hyun Baekt

    2000-01-01

    Full Text Available A numerical study is conducted on the fully-developed laminar flow of an incompressible viscous fluid in a square duct rotating about a perpendicular axis to the axial direction of the duct. At the straight duct, the rotation produces vortices due to the Coriolis force. Generally two vortex cells are formed and the axial velocity distribution is distorted by the effect of this Coriolis force. When a convective force is weak, two counter-rotating vortices are shown with a quasi-parabolic axial velocity profile for weak rotation rates. As the rotation rate increases, the axial velocity on the vertical centreline of the duct begins to flatten and the location of vorticity center is moved near to wall by the effect of the Coriolis force. When the convective inertia force is strong, a double-vortex secondary flow appears in the transverse planes of the duct for weak rotation rates but as the speed of rotation increases the secondary flow is shown to split into an asymmetric configuration of four counter-rotating vortices. If the rotation rates are increased further, the secondary flow restabilizes to a slightly asymmetric double-vortex configuration. Also, a numerical study is conducted on the laminar flow of an incompressible viscous fluid in a 90°-bend square duct that rotates about axis parallel to the axial direction of the inlet. At a 90°-bend square duct, the feature of flow by the effect of a Coriolis force and a centrifugal force, namely a secondary flow by the centrifugal force in the curved region and the Coriolis force in the downstream region, is shown since the centrifugal force in curved region and the Coriolis force in downstream region are dominant respectively.

  9. Elliptic curves for applications (Tutorial)

    NARCIS (Netherlands)

    Lange, T.; Bernstein, D.J.; Chatterjee, S.

    2011-01-01

    More than 25 years ago, elliptic curves over finite fields were suggested as a group in which the Discrete Logarithm Problem (DLP) can be hard. Since then many researchers have scrutinized the security of the DLP on elliptic curves with the result that for suitably chosen curves only exponential

  10. Titration Curves: Fact and Fiction.

    Science.gov (United States)

    Chamberlain, John

    1997-01-01

    Discusses ways in which datalogging equipment can enable titration curves to be measured accurately and how computing power can be used to predict the shape of curves. Highlights include sources of error, use of spreadsheets to generate titration curves, titration of a weak acid with a strong alkali, dibasic acids, weak acid and weak base, and…

  11. A Journey Between Two Curves

    Directory of Open Access Journals (Sweden)

    Sergey A. Cherkis

    2007-03-01

    Full Text Available A typical solution of an integrable system is described in terms of a holomorphic curve and a line bundle over it. The curve provides the action variables while the time evolution is a linear flow on the curve's Jacobian. Even though the system of Nahm equations is closely related to the Hitchin system, the curves appearing in these two cases have very different nature. The former can be described in terms of some classical scattering problem while the latter provides a solution to some Seiberg-Witten gauge theory. This note identifies the setup in which one can formulate the question of relating the two curves.

  12. Clinical and angiographic characteristics of young adult patients recovered from acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Miljković Dušan

    2015-01-01

    Full Text Available Introduction. Occurrence of acute myocardial infarction in young adults is a relatively rare. In majority of the studies, age of 45 years is used as cut-off line in definition of the young patients with coronary artery disease or myocardial infarction. Studies have shown that younger population aged less than 40 years represents only 2-8% of all patients with myocardial infarction. Objective. The aim of this study was to examine the specificities of clinical and angiographic characteristics of the patients recovered from acute myocardial infarction, younger than 45 years at the moment of attack, by comparing their clinical and angiographic characteristics with those of patients older than 65 years, who recovered from acute myocardial infarction. Method. The study included 78 patients recovered from acute myocardial infarction, 33 patients were younger than 45 years (40.7 ± 3.9 years, 25 (75.7% men and eight (24.2% female, and 45 patients were older than 65 years (68.2 ± 4.2 years, 32 (71.3% men and 13 women. Detailed history taking, physical examination, permanent ECG monitoring, laboratory analyses, X-ray examination, echocardiography and selective coronarography of all patients were performed. Results. Patients younger than 45 years had a significantly higher incidence of STEMI (p 0.05 Multivessel disease existed at 54.5% under the age of 45 and 77.8% older than 65 years (p0.05. The disease of left main coronary artery had 6.1% of patients younger than 45 and 22.2% of patients older than 65 years (p0.05 Were without significant coronary artery stenosis Comparing risk factors for coronary artery disease in patients younger than 45 years and older than 65 years, we find: hypertension in 48.5% vs. 88.9% (p0.05, diabetes mellitus in 21.2% vs. 55.5% (p 0.05, and stress in 18.2% vs. 2.2% (p <0.01. Conclusion. Patients with myocardial infarction younger than 45 years are predominantly male and have a significantly higher incidence of infarction

  13. Idiopathic polypoidal choroidal vasculopathy in Thai patients with clinical and angiographic choroidal neovascularization

    Directory of Open Access Journals (Sweden)

    Bhoomibunchoo C

    2017-02-01

    Full Text Available Chavakij Bhoomibunchoo,1 Yosanan Yospaiboon,1 Somanus Thoongsuwan,2 Duangnate Rojanaporn,3 Nawat Watanachai,4 Pichai Jirarattanasopa,5 Nattapon Wongcumchang,6 Atchara Amphornphruet,7 Sritatath Vongkulsiri,8 Eakkachai Arayangkoon9 1Department of Ophthalmology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 2Department of Ophthalmology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, 3Department of Ophthalmology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, 4Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 5Department of Ophthalmology, Faculty of Medicine, Prince of Songkla University, Songkhla, 6Department of Ophthalmology, Faculty of Medicine, Thammasat University, Pathum Thani, 7Department of Ophthalmology, Rajavithi Hospital, Bangkok, 8Department of Ophthalmology, Phramongkutklao Hospital, Bangkok, 9Department of Ophthalmology, Mettapracharak Hospital, Nakhon Pathom, Thailand Objective: This study aimed to study the prevalence and characteristics of idiopathic polypoidal choroidal vasculopathy (IPCV in Thai patients with clinical and angiographic choroidal neovascularization (CNV.Patients and methods: A consecutive case study of 140 patients presenting with CNV was conducted in nine large referral eye centers throughout Thailand. The demographic data, fundus photographs, fundus fluorescein angiography and indocyanine green angiography of the patients were analyzed.Results: Of 129 patients with clinical and angiographic CNV, IPCV was diagnosed in 100 patients (77.52%, idiopathic CNVs in 16 patients (12.40% and age-related macular degeneration (AMD in 12 patients (9.30%. Of the 107 eyes with IPCV, 90 eyes (84.11% had both branching venous networks (BVNs and polypoidal lesions. Most IPCV patients (93% had unilateral involvement and were at a younger age than AMD patients. In all, 79 eyes (73.83% had lesions found in the macular area, 14 eyes (13.08% in the

  14. Clinical and angiographic evaluation of the topic application of nitrate compounds in obstructive distal arteriopathies of the legs

    International Nuclear Information System (INIS)

    Perini, L.; Cavallo, A.; Perin, B.; Natale, F.; Borelli, G.; Bisiato, R.

    1988-01-01

    The vasodilatator effect obtained by the topic use of a nytroglycerin compound (TNG) has been angiographically tested on 11 patients affected by distal arteriopathy of the legs. All patients presented arteriosclerotic vascular lesions; two of them also suffered from diabetic angiopathy. Arteriography of the legs has proved to be a very important tool in the evaluation of the patients'response to the administration of the drug. An hour after 80 mg of TNG had been applied to the skin of the examined leg, arteriography showed a marked dilatation, especially of the muscular arteries and the undamaged tracts of the arteries of the legs. Angiographic evaluation of the functional blood supply thus obtained provides prognostic information and helps in the choice of the subsequent therapy. Furthermore, the clinical efficacy of prolonged treatment with this drug has been tested in 10 out of the 11 patients. They all responded with an immediate and persistent hemodynamic improvement, evaluated according to Fontaine's classification

  15. Transit-time flow measurement as a predictor of coronary bypass graft failure at one year angiographic follow-up

    DEFF Research Database (Denmark)

    Lehnert, Per; Møller, Christian H; Damgaard, Sune

    2015-01-01

    on graft vessel type, anastomatic configuration, and coronary artery size. RESULTS: Nine hundred eighty-two coronary anastomoses were performed of which 12% had signs of graft failure at one year angiographic follow-up. In internal mammary arteries (IMAs), analysis showed a 4% decrease in graft failure......BACKGROUND: Transit-time flow measurement (TTFM) is a commonly used intraoperative method for evaluation of coronary artery bypass graft (CABG) anastomoses. This study was undertaken to determine whether TTFM can also be used to predict graft patency at one year postsurgery. METHODS: Three hundred...... forty-five CABG patients with intraoperative graft flow measurements and one year angiographic follow-up were analyzed. Graft failure was defined as more than 50% stenosis including the "string sign." Logistic regression analysis was used to analyze the risk of graft failure after one year based...

  16. Soil Water Retention Curve

    Science.gov (United States)

    Johnson, L. E.; Kim, J.; Cifelli, R.; Chandra, C. V.

    2016-12-01

    Potential water retention, S, is one of parameters commonly used in hydrologic modeling for soil moisture accounting. Physically, S indicates total amount of water which can be stored in soil and is expressed in units of depth. S can be represented as a change of soil moisture content and in this context is commonly used to estimate direct runoff, especially in the Soil Conservation Service (SCS) curve number (CN) method. Generally, the lumped and the distributed hydrologic models can easily use the SCS-CN method to estimate direct runoff. Changes in potential water retention have been used in previous SCS-CN studies; however, these studies have focused on long-term hydrologic simulations where S is allowed to vary at the daily time scale. While useful for hydrologic events that span multiple days, the resolution is too coarse for short-term applications such as flash flood events where S may not recover its full potential. In this study, a new method for estimating a time-variable potential water retention at hourly time-scales is presented. The methodology is applied for the Napa River basin, California. The streamflow gage at St Helena, located in the upper reaches of the basin, is used as the control gage site to evaluate the model performance as it is has minimal influences by reservoirs and diversions. Rainfall events from 2011 to 2012 are used for estimating the event-based SCS CN to transfer to S. As a result, we have derived the potential water retention curve and it is classified into three sections depending on the relative change in S. The first is a negative slope section arising from the difference in the rate of moving water through the soil column, the second is a zero change section representing the initial recovery the potential water retention, and the third is a positive change section representing the full recovery of the potential water retention. Also, we found that the soil water moving has traffic jam within 24 hours after finished first

  17. CT Angiographic Demonstration of a Mesenteric Vessel 'Whirlpool' in Intestinal Malrotation and Midgut Volvulus: a Case Report

    International Nuclear Information System (INIS)

    Bozlar, Ugur; Ugurel, Mehmet Sahin; Ustunsoz, Bahri; Coskun, Unsal

    2008-01-01

    Although the color Doppler ultrasonography diagnosis of intestinal malrotation with midgut volvulus, based on the typical 'whirlpool' appearance of the mesenteric vascular structures is well-defined in the peer-reviewed literature, the combination of both the angiographic illustration of these findings and the contemporary state-of-the-art imaging techniques is lacking. We report the digital subtraction angiography and multidetector computed tomography angiography findings of a 37-year-old male with intestinal malrotation

  18. CT Angiographic Demonstration of a Mesenteric Vessel 'Whirlpool' in Intestinal Malrotation and Midgut Volvulus: a Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Bozlar, Ugur; Ugurel, Mehmet Sahin; Ustunsoz, Bahri [Gulhane Military Medical Academy, Ankara (Turkmenistan); Coskun, Unsal [Gulhane Military Medical Academy, Turkish Armed Forces Rehabilitation Center, Ankara (Turkmenistan)

    2008-10-15

    Although the color Doppler ultrasonography diagnosis of intestinal malrotation with midgut volvulus, based on the typical 'whirlpool' appearance of the mesenteric vascular structures is well-defined in the peer-reviewed literature, the combination of both the angiographic illustration of these findings and the contemporary state-of-the-art imaging techniques is lacking. We report the digital subtraction angiography and multidetector computed tomography angiography findings of a 37-year-old male with intestinal malrotation.

  19. The value of regional wall motion abnormalities on gated mycardiac perfusion imaging in perfusion imaging in predicting angiographic stenoses of coronary artery

    International Nuclear Information System (INIS)

    Yao Lixin; Liu Binbin

    2007-01-01

    Objective: To determine the possible level of angiographic stenoses of coronary artery at which reversible regional wall motion abnormalities (RWMA) are present on 99m Tc-sestamibi ( 99m Tc-MIBI)-gated myocardial perfusion imaging (MPI). Methods: ninty patients undergoing coronary angiography MPI within two weeks were recruited. A five grades and nine segments marking system was introduced to assess the RWMA and thickening of left ventricles. Results: The sensitivity of reversible RWMA for detecting ≥75% angiographic stenoses was 64%,with a specificity of 95% and positive predictive value of 97%. The presence of reversible RWMA was able to stratify patients with severe angiographic stenoses of 75% or more from those less than 75% with high positive predictive value. A good correlation was noted between the presence of reversible RWMA and the coronary artery jeopardy score. Multivariate analysis showed that the post-stress RWMA and reversible RWMA scores and positive dipyridamole-stress exercise electrocardiogram(ECG) were significant predictors of angiographic severity. Conclusions: Reversible RWMA, as shown by dipyridamole stress 99m Tc-MIBI MPI, is a significant predictor of angiographic disease with very high specificity and adds incremental value to MPI for the assessment of angiographic severity. (authors)

  20. Angiographic evaluation of the effect of intra-arterial milrinone therapy in patients with vasospasm from aneurysmal subarachnoid hemorrhage.

    Science.gov (United States)

    Shankar, Jai Jai Shiva; dos Santos, Marlise P; Deus-Silva, Leonardo; Lum, Cheemun

    2011-02-01

    Several methods have been used to treat cerebral vasospasm, which is a major cause of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (SAH). Here, we examined the effectiveness and safety of intra-arterial injection of milrinone for the treatment of vasospasm. Consecutive patients with angiographically confirmed vasospasm received intra-arterial milrinone between January 2006 and December 2007. The improvement in diameter of vessel (in millimeters) following treatment was assessed by paired t test for statistical significance. The angiographic improvement of supraclinoid internal carotid artery, M1 segment of middle cerebral artery, and A1 and A2 segment of anterior cerebral artery was compared with the modified Rankin score of the patients at discharge. A total of 15 milrinone treatments were performed in 14 patients (11 females and 3 males) with mean age of 52.7 years (31-68 years). There was significant angiographic improvement after milrinone therapy (p milrinone was a safe and effective treatment of cerebral vasospasm following aneurysmal SAH.

  1. Superselective angiographic findings and the blood supply in the cases of avascular necrosis of the femoral head: a preliminary study

    International Nuclear Information System (INIS)

    Zhou Weisheng; Wang Fangjun; Ling Yisheng; Zhao Tianqing

    2003-01-01

    Objective: To study the superselective angiographic findings and blood supply in the case of avascular necrosis of the femoral head (ANFH). Methods: One hundred and sixty five patients (214 hips) with ANFH proved by clinic and radiology underwent superselective angiography and DSA findings were retrospectively studied. Results: Abnormal angiographic findings of the medial circumflex artery and its branches, with or without other abnormal vascularities, could be obtained in 162 hips out of 211 (98.6%). Angiographic findings of ANFH were the followings: abnormal superior and inferior capsular branch of the medial circumflex artery, especially the former one; abnormalities in the ascending branch of lateral circumflex artery; opacification of the femoral head and neck in the parenchymal phase of DSA; revasculization of the small arterial branches or a hypervascular area surrounding the necrotic lesions; anastomosis between the medial circumflex artery and the inferior and superior gluteal arteries; and the venous stasis. Conclusion: Morphological changes of blood vessels in ANFH are demonstrated by superselective angiography, in which the medial circumflex artery and its branches are mostly involved, or in some cases, accompanied by venous stasis

  2. Angiographic Evaluation of Carotid Artery Grafting with Prefabricated Small-Diameter, Small-Intestinal Submucosa Grafts in Sheep

    International Nuclear Information System (INIS)

    Pavcnik, Dusan; Obermiller, Josef; Uchida, Barry T.; Van Alstine, William; Edwards, James M.; Landry, Gregory J.; Kaufman, John A.; Keller, Frederick S.; Roesch, Josef

    2009-01-01

    The purpose of this study was to report the longitudinal angiographic evaluation of prefabricated lyophilized small-intestinal submucosa (SIS) grafts placed in ovine carotid arteries and to demonstrate a variety of complications that developed. A total of 24 grafts, 10 cm long and 6 mm in diameter, were placed surgically as interposition grafts. Graft patency at 1 week was evaluated by Doppler ultrasound, and angiography was used for follow-up at 1 month and at 3 to 4 months. A 90% patency rate was found at 1 week, 65% at 1 month, and 30% at 3 to 4 months. On the patent grafts, angiography demonstrated a variety of changes, such as anastomotic stenoses, graft diffuse dilations and dissections, and aneurysm formation. These findings have not been previously demonstrated angiographically by other investigators reporting results with small-diameter vessel grafts made from fresh small-intestinal submucosa (SIS). The complications found were partially related to the graft construction from four SIS layers. Detailed longitudinal angiographic study should become an essential part of any future evaluation of small-vessel SIS grafting.

  3. Fermions in curved spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Lippoldt, Stefan

    2016-01-21

    In this thesis we study a formulation of Dirac fermions in curved spacetime that respects general coordinate invariance as well as invariance under local spin base transformations. We emphasize the advantages of the spin base invariant formalism both from a conceptual as well as from a practical viewpoint. This suggests that local spin base invariance should be added to the list of (effective) properties of (quantum) gravity theories. We find support for this viewpoint by the explicit construction of a global realization of the Clifford algebra on a 2-sphere which is impossible in the spin-base non-invariant vielbein formalism. The natural variables for this formulation are spacetime-dependent Dirac matrices subject to the Clifford-algebra constraint. In particular, a coframe, i.e. vielbein field is not required. We disclose the hidden spin base invariance of the vielbein formalism. Explicit formulas for the spin connection as a function of the Dirac matrices are found. This connection consists of a canonical part that is completely fixed in terms of the Dirac matrices and a free part that can be interpreted as spin torsion. The common Lorentz symmetric gauge for the vielbein is constructed for the Dirac matrices, even for metrics which are not linearly connected. Under certain criteria, it constitutes the simplest possible gauge, demonstrating why this gauge is so useful. Using the spin base formulation for building a field theory of quantized gravity and matter fields, we show that it suffices to quantize the metric and the matter fields. This observation is of particular relevance for field theory approaches to quantum gravity, as it can serve for a purely metric-based quantization scheme for gravity even in the presence of fermions. Hence, in the second part of this thesis we critically examine the gauge, and the field-parametrization dependence of renormalization group flows in the vicinity of non-Gaussian fixed points in quantum gravity. While physical

  4. Comparison of angiographic, gammagraphic, and histological data in orbital tumours: concerning 13 observations

    International Nuclear Information System (INIS)

    Emery, M.T.

    1976-01-01

    The aim of this work is to compare the value of gammagraphic and angiographic examinations in intra-orbital expansive processes and to hole for a histological explanation when the two examinations disagree. All the gammagraphs used were obtained with technetium 99m-labelled ferrous ascorbate. Orbital gammagraphy requires a radioelement combining the advantages of easily detectable radioactivity and fast elimination from healthy tissues while keeping a strong tumoral uptake. Sup(99m)Tc-labelled ferrous ascorbate fulfils these conditions. Technetium 99m, perfectly safe because of its short half-life and low radiation energy, allows the scintigraphic detection of expansive processes. By its association with ferrous ascorbate, which has a very high kidney and plasma clearance rate, the vascular background is reduced considerably and the relative radiotracer concentration in the diseased area increased (the background is due to fixation of the radioelement in the facial and orbital muscles, the mucous membranes of the nose and sinus and the vein sinuses at the base of the skull). The complex used in this study is obtained from 40mg ferrous ascorbate to which are added 1ml Thris buffer at pH 7.85 and 5ml 99mTc pertechnetate solution. 10 to 15 microcuries are injected intraveinously or absorbed parenterally [fr

  5. Angiographic aspect of the distal forelimb in donkeys (Equus asinus used for animal traction

    Directory of Open Access Journals (Sweden)

    Maria Angélica Miglino

    2009-12-01

    Full Text Available The asinine species was originated thousands of years ago from the same branch of domestic equine. Asinines have been undergoing a great adaptation resulting in different characteristics observed in their populations around the world. In the northeastern region of Brazil, they play an essential role in the economy of local families. Due to a large number of locomotor disorders and a lack of professional care for these animals, a radiographic study of the distal forelimb region of the asinine was carried out in order to gather information for the improvement of clinical and surgical practices in this species, and to explain their low susceptibility to locomotor disorders compared to that of the domestic equine. The angiographic examination revealed the main arterial vessels committed to the blood supply of the forelimbs in these animals, providing evidence of the vascular pattern of the median and palmar common digital arteries, which originated a great number of collateral branches, mainly to the distal phalanx. The distal forelimbs in donkeys have shown great vascular anastomosis, promoting additional blood supply to the deep endosteum and periosteum regions, probably as a response to the physical activity developed by these animals.

  6. Angiographic CT with intravenous contrast agent application for monitoring of intracranial flow diverting stents

    International Nuclear Information System (INIS)

    Saake, Marc; Struffert, Tobias; Goelitz, Philipp; Ott, Sabine; Doerfler, Arnd; Seifert, Frank; Ganslandt, Oliver

    2012-01-01

    Intracranial flow diverting devices are increasingly used to treat cerebral aneurysms. A reliable, non-invasive follow-up modality would be desirable. Our aim was to compare intra-arterial digital subtraction angiography (ia DSA) to angiographic computed tomography with intravenous contrast agent application (iv ACT) in the visualisation of flow diverting devices and aneurysm lumina. Follow-up monitoring by iv ACT (n = 36) and ia DSA (n = 25) in 14 patients treated with flow diverting devices for intracranial aneurysms was evaluated retrospectively. Images were evaluated by two neuroradiologists in anonymous consensus reading regarding the device deployment, wall apposition, neck coverage of the aneurysm, opacification of the vessel and device lumen, as well as the degree of aneurysm occlusion. Corresponding ia DSA and iv ACT images were scored identically in all patients regarding the stent deployment, wall apposition and neck coverage, as well as the degree of aneurysm occlusion and patency status of the device and parent artery. Opacification of the parent vessel lumen and perfused parts of the aneurysm was considered slightly inferior for iv ACT in comparison with ia DSA (seven of 36 cases), without impact on diagnosis. We demonstrated the feasibility and diagnostic value of iv ACT in follow-up imaging of intracranial flow diverting devices. Due to its high spatial resolution and non-invasive character, this novel technique might become a valuable imaging modality in these patients. (orig.)

  7. Invaded depth of extrahepatic bile duct cancer diagnosed on angiographic CT during late contrast enhancement

    International Nuclear Information System (INIS)

    Kikuyama, Masataka; Sasada, Yuzo; Koide, Shigeki; Hirai, Ritsuko; Oota, Yuji

    2006-01-01

    Thirteen patients with extrahepatic bile duct cancer were evaluated for enhancement pattern and tumor feature during late contrast enhancement on angiographic CT (AG-CT), performed before surgery. Eleven patients with late contrast enhancement had advanced cancers with invasion over the subserosal layer. Eight of these patients whose cancer had an irregular outer layer had invasion over the serosal layer (≥panc 1 b, General Rules for Surgical and Pathological Studies on Cancer of the Biliary Tract, Japanese Society of Biliary Surgery). Seven of the 13 patients had intra-pancreatic bile duct cancer. Among them, five had an irregular outer layer of the intra-pancreatic bile duct cancer; one of three with a wall thickness under 5 mm on AG-CT had panc 1 b invasion, and the other two had panc 2 (General Rules for Surgical and Pathological Studies on Cancer of the Biliary Tract, Japanese Society of Biliary Surgery) invasion. Two with a wall thickness over 5 mm on AG-CT had panc 2 invasion. These results suggest that late contrast enhancement on AG-CT is effective for diagnosing the depth of tumor invasion of the bile duct. (author)

  8. An approach of long-view tomosynthesis in peripheral arterial angiographic examinations

    Science.gov (United States)

    Notohara, Daisuke; Nishino, Kazuyoshi; Shibata, Koichi

    2011-03-01

    Tomosynthesis (TS) has been evaluated as a useful diagnostic imaging tool for the orthopedic market and lung cancer screening. Previously, we proposed Long-View Tomosynthesis (LVTS) to apply further clinical application by expanding the reconstructed region of TS. LVTS method consists of three steps. First, it acquires multiple images while X-ray tube and Flat Panel Detector (FPD) are moving in the same linear direction simultaneously at a constant speed. Second, each image is divided into fixed length strips, and then the strips from different images having similar X-ray beam trajectory angles are stitched together. Last, multi slice coronal images are reconstructed by utilizing the Filtered Back Projection (FBP) technique from the long stitched images. The present LVTS method requires the acquisition by the constant speed motion to stitch each strip precisely. It is necessary to improve the LVTS method to apply peripheral angiographic examinations that are usually acquired at arbitrary variable speeds to chase the contrast media in the blood vessel. We propose adding the method of detecting the moved distance of frames along with anatomical structure and the method of selecting pixel values with contrast media to stitching algorithm. As a result, LVTS can extract new clinical information like 3-D structure of superficial femoral arteries and the entire blood vessel from images already acquired by routine bolus chasing techniques.

  9. Super selective transcatheter angiographic embolization: an effective and prophylactic treatment for massive obstetric haemorrhage

    International Nuclear Information System (INIS)

    Zhou Yiming; Zhai Renyou; Qian Xiaojun; Wei Baojie; Gao Kun; Zhang Shilong; Liu Jinmei; Zhang Qiuhong; Jiang Lei

    2008-01-01

    Objective: To discuss the effect and safety of transcatheter angiographic embolization (TAE)for managing massive obstetric haemorrhage. Methods: 17 cases of obstetric massive haemorrhage or with haemorrhage tendency were treated with TAE. Among them 14 cases had haemorrhage already, including 10 cases after abortion, caesarean section or normal labor and other 4 of hydatidiform mole. 3 cases with obstetric haemorrhage tendency included 2 cases of placenta praevia and 1 case of cervical pregnancy. Selective catheterization into bilateral uterine arteries or internal iliac arteries for DSA, showed the cause and location of the haemorrhage and then embolized with gelfoam sponge chips (1-3 mm) or Polyvinyl Alcohol(PVA); and part of the cases with MTX through uterine arterial perfusion. Results: The successful rate of catheterization was 100%. The achievement in 14 cases showed no active haemorrhage immediately after the procedure and no vaginal bleeding after 1-5 days. In 3 prophylactic cases before abortion or uterine curettage, obstetric massive haemorrhage occurred in 1 case, but not so in other 2 cases. Conclusions: TAE is an effective treatment for obstetric massive haemorrhage, with the advantages of minimal trauma, fast and definite treating effect and less complications. Prophylactical application for high risk patients can reduce the bleeding and mortality. (authors)

  10. [Evaluation of fundus autofluorescence in hereditary retinal diseases using Heidelberg Retina Angiograph2].

    Science.gov (United States)

    Côco, Monique; Baba, Natalia Tamie; Sallum, Juliana Maria Ferraz

    2007-01-01

    To define characteristics of the fundus autofluorescence examination, verifying usefulness in the diagnosis and care of hereditary retinal diseases. 28 patients, adults, divided equally into four groups with diagnoses of Stargardt macular dystrophy, cone dystrophy, retinitis pigmentosa and healthy volunteers for the establishment of the normality pattern. An average of nine images with the filter for fluorescein angiography was obtained for the formation of the image autofluorescence using Heidelberg Retina Angiograph2. The images of each group of patients were analyzed to verify common characteristics. The fundus autofluorescence of healthy volunteers showed the foveal area darker than the surrounding retina. The images of Stargardt macular dystrophy, in general, presented an oval central lesion, with reduced autofluorescence. The main alterations of the autofluorescence in patients with cone dystrophy were reduced foveal autofluorescence with a parafoveal ring of increased autofluorescence. In general, the images of retinitis pigmentosa showed outlying pigments with reduced autofluorescence, and of the foveal area, in some cases disorganization or reduced autofluorescence. The study showed the existence of patterns of fundus autofluorescence in the hereditary retinal diseases that allow the diagnosis and better interpretation of the pathogenesis of these diseases.

  11. Effect of Asparagus racemosus on fracture healing in rabbits: a radiographic and angiographic study

    International Nuclear Information System (INIS)

    Singh, Sunil; Singh, H.N.; Gangwar, A.K.; Devi, Kh. Sangeeta; Waghay, J.Y.

    2009-01-01

    New Zealand white rabbits (18) were randomly divided into groups I and II (control) having 9 animals in each group. The fracture of ulna was created in each animal under general anaesthesia using thiopental sodium (2.5%). Radius acted as a natural splint. The animals of group I were fed with powdered Asparagus racemosus along with rabbit feed throughout the study period. However, in group II animals only powdered rabbit feed was given. Healing at the fracture site was assessed by plain radiography and angiography at 7th, 14th, 21st and 28th day interval. Radiographical observation revealed a well organized and dense callus at 21st day in animals of group I whereas in animals of group II, callus of slightly less radiographic density was observed at this interval. Angiographic observation revealed hypervascularity at the fracture site at 7th and 14th day interval in group I animals. On day 14, in group II animals major vessels lack continuity along with reduced vascularity around the fracture site. The results of present study suggest that feeding of dry root powder of Asparagus racemosus promotes early fracture healing in rabbits

  12. Coronary artery ectasia, its clinical profile and angiographic characteristics, single centre experience

    International Nuclear Information System (INIS)

    Ahmed, N.; Mohyudin, M.T.; Saad, A.A.; Iqbal, M.M.

    2013-01-01

    Objective: To evaluate the incidence of coronary ectasia and its, its clinical profile and angiographic characteristics in our population. Methods: A retrospective analysis was conducted on all coronary angiograms performed at the catheterization laboratory of Ch. Pervaiz Elahi Institute of Cardiology, Multan between the period of January 2011 and December 2012. Data were collected from catheterization films, and medical records. Results: In a total of 6540 coronary angiograms were performed during the period of the study. A total of 225 (3.44%) angiograms showed coronary ectasia of both mixed and pure types. Pure ectasia with no coronary obstructive lesions was seen in 58 (25.77%). Type 4 was most common 95 pts. (42.22%), as per the Markis classification. Right coronary artery (RCA) was the most commonly affected vessel 162 (72%) followed by left anterior descending artery (LAD) 76 (33.78%) and 38 patients (16.88%) patients had circumflex artery involvement. 132 patients (58.66%) had good left ventricular (LV) systolic function. Conclusion: Prevalence of Coronary ectasia in the population presenting to Ch. Pervaiz Elahi Institute of Cardiology, Multan during the study period was 3.4%. Majority of patients were males, associated with, hypertension and diabetes mellitus. CAE was associated with obstructive coronary artery disease in about 74.22% of cases. RCA was the most commonly affected vessel. (author)

  13. High-Resolution CT and Angiographic Evaluation of NexStent Wall Adaptation

    International Nuclear Information System (INIS)

    Nemes, Balazs; Lukacs, Levente; Balazs, Gyoergy; Dosa, Edit; Berczi, Viktor; Huettl, Kalman

    2009-01-01

    Carotid stenting is a minimally invasive treatment for extracranial carotid artery stenosis. Stent design may affect technical success and complications in a certain subgroup of patients. We examined the wall adaptability of a new closed-cell carotid stent (NexStent), which has a unique rolled sheet design. Forty-one patients had 42 carotid arteries treated with angioplasty and stenting for internal carotid artery stenosis. The mean patient age was 65 ± 10 years. All patients underwent high-resolution computed tomographic angiography after the stent implantation. Data analysis included pre- and postprocedural stenosis, procedure complications, plaque calcification, and stent apposition. We reviewed the angiographic and computed tomographic images for plaque coverage and stent expansion. All procedures were technically successful. Mean stenosis was reduced from 84 ± 8% before the procedure to 15.7 ± 7% after stenting. Two patients experienced transient ischemic attack; one patient had bradycardia and hypotension. Stent induced kinking was observed in one case. Good plaque coverage and proper overlapping of the rolled sheet was achieved in all cases. There was weak correlation between the residual stenosis and the amount of calcification. The stent provides adequate expansion and adaptation to the tapering anatomy of the bifurcation.

  14. Angiographically occult vascular malformation of the brain: MR imaging at 1.5 T

    International Nuclear Information System (INIS)

    Patel, S.C.; Sanders, W.P.; Fuentes, J.; Haggar, A.M.; Mehta, B.A.; Boulos, R.S.; Froelich, J.W.

    1986-01-01

    MR imaging was performed in nine patients with 12 angiographically occult arteriovenous malformations using a 1.5-T superconducting magnet; four additional patients were imaged using a 0.3-T system. All images were reviewed in conjunction with CT scans. The following observations were made. (1) Eleven of 14 supratentorial lesions were located at the junction of gray and white matter. (2) Exclusing acute hemorrhage, only two lesions displayed mild mass effect. (3) All lesions displayed central foci of high signal intensity, probably representing subacute hemorrhage. (4) All lesions but one showed a peripheral rim of low signal intensity which progressively lost signal with increasing T2 weighting. This most likely represents iron-containing hemosiderin deposition. (5) Lesions were best demonstrated with long repetition times and moderate T2 weighting (TR = 2,500 msec, TE = 25-100 msec). (6) All lesions but one were hyperdense on non-contrast-enhanced CT, although only three had unequivocal calcification. The possibility of hyperdensity due to blood or iron deposition is discussed

  15. Local organ dose conversion coefficients for angiographic examinations of coronary arteries

    International Nuclear Information System (INIS)

    Schlattl, H; Zankl, M; Hausleiter, J; Hoeschen, C

    2007-01-01

    New organ dose conversion coefficients for coronary angiographic interventions are presented, as well as dose distributions and resulting maximal local dose conversion coefficients in the relevant organs. For the Monte Carlo based simulations, voxel models of the human anatomy were employed which represent the average Caucasian adult man and woman as defined by the International Commission on Radiological Protection. In the 21 investigated projections, the mean organ dose conversion coefficients vary from a few 0.01 to 2 mGy(Gy cm 2 ) -1 , depending on the projections. However, especially in portions of the lungs and the active bone marrow, the conversion coefficients can locally amount up to 10 mGy(Gy cm 2 ) -1 , which is half the average conversion coefficient of the skin at the field entrance. In addition to the dose conversion coefficients, the dependence of the patient dose on the projection has been estimated. It could be shown that the patient doses are highest for left anterior oblique views with strong caudal or cranial orientation. Nevertheless, for a large range of image-intensifier positions no significant dose differences could be found

  16. Determination of optimal angiographic viewing angles: Basic principles and evaluation study

    International Nuclear Information System (INIS)

    Dumay, A.C.M.; Reiber, J.H.C.; Gerbrands, J.J.

    1994-01-01

    Foreshortening of vessel segments in angiographic (biplane) projection images may cause misinterpretation of the extent and degree of coronary artery disease. The views in which the object of interest are visualized with minimum foreshortening are called optimal views. In this paper the authors present a complete approach to obtain such views with computer-assisted techniques. The object of interest is first visualized in two arbitrary views. Two landmarks of the object are manually defined in the two projection images. With complete information of the projection geometry, the vector representation of the object in the three-dimensional space is computed. This vector is perpendicular to a plane in which the views are called optimal. The user has one degree of freedom to define a set of optimal biplane views. The angle between the central beams of the imaging systems can be chosen freely. The computation of the orientation of the object and of corresponding optimal biplane views have been evaluated with a simple hardware phantom. The mean and the standard deviation of the overall errors in the calculation of the optimal angulation angles were 1.8 degree and 1.3 degree, respectively, when the user defined a rotation angle

  17. Angiographic CT: in vitro comparison of different carotid artery stents-does stent orientation matter?

    Science.gov (United States)

    Lettau, Michael; Bendszus, Martin; Hähnel, Stefan

    2013-06-01

    Our aim was to evaluate the in vitro visualization of different carotid artery stents on angiographic CT (ACT). Of particular interest was the influence of stent orientation to the angiography system by measurement of artificial lumen narrowing (ALN) caused by the stent material within the stented vessel segment to determine whether ACT can be used to detect restenosis within the stent. ACT appearances of 17 carotid artery stents of different designs and sizes (4.0 to 11.0 mm) were investigated in vitro. Stents were placed in different orientations to the angiography system. Standard algorithm image reconstruction and stent-optimized algorithm image reconstruction was performed. For each stent, ALN was calculated. With standard algorithm image reconstruction, ALN ranged from 19.0 to 43.6 %. With stent-optimized algorithm image reconstruction, ALN was significantly lower and ranged from 8.2 to 18.7 %. Stent struts could be visualized in all stents. Differences in ALN between the different stent orientations to the angiography system were not significant. ACT evaluation of vessel patency after stent placement is possible but is impaired by ALN. Stent orientation of the stents to the angiography system did not significantly influence ALN. Stent-optimized algorithm image reconstruction decreases ALN but further research is required to define the visibility of in-stent stenosis depending on image reconstruction.

  18. [Myocardial infarction related to sport. Acute clinical and coronary angiographic characteristics in 16 cases].

    Science.gov (United States)

    Halna du Fretay, X; Akoudad, H; Nejjari, M; Benamer, H

    2013-12-01

    Determination of clinical and angiographic characteristics of myocardial infarctions related to sport. Retrospective study of acute coronary syndromes with ST elevation related to sport treated with interventional cardiology from 2006 to 2013. Sixteen patients were included. They are mostly men (15/16), aged 24-65 years (over 35 years old in 13 cases) with few cardiovascular risk factors, most frequently heredity or smoking. Myocardial infarctions usually occur during the practice of sports (13/16), with serious rhythmic complications in three of the cases. On angiography, most patients have single vessel disease (12/16). Myocardial infarction related to sports affects a male population aged over 35 years old with few cardiovascular risk factors, most often single vessel disease, making the preventative screening uneasy. Other studies investigating larger populations, assessing previous clinical events (symptoms, results of stress tests), evaluating the impact of competition and integrating sudden deaths would improve the screening and the treatment of sport-related myocardial infarctions. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  19. Multi-detector CT coronary angiographic findings of coronary-to-pulmonary artery fistula

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jae Seok; Park, Eun Ah; Lim, Ji Yeon; Lee, Whal [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Park, Jae Hyung [Dept. of Radiology, Myongji Hospital, Seonam University College of Medicine, Goyang (Korea, Republic of)

    2017-01-15

    To evaluate multi-detector CT (MDCT) coronary angiographic findings of coronary-to-pulmonary artery fistula (CPAF). We retrospectively reviewed images of patients with CPAF from the coronary CT angiography (CCTA) database obtained with a 64-channel MDCT between January 2008 and March 2011. We analyzed the CCTA findings for feeding arteries, fistula, association with peripulmonary arterial aneurysms, and the presence of communication between the CPAF and bronchial arteries. Fifty-five of the 15042 (0.37%) patients were diagnosed with CPAFs. The feeding artery was single (n = 18) or multiple (n = 37). The fistula had a single drainage site (n = 54) or multiple drainage sites (n = 1). The mean diameter of the fistulous opening was 2.7 ± 1.4 mm. A peripulmonary arterial aneurysm was present in 24 (44%) patients. Communication between CPAF and bronchial arteries was present in eight (14.5%) patients. MDCT coronary angiography can provide comprehensive morphologic details on CPAF and may help in presurgical or preinterventional planning.

  20. Cerebellar arteries originating from the internal carotid artery: angiographic evaluation and embryologic explanations

    International Nuclear Information System (INIS)

    Lee, Jae Young; Han, Moon Hee; Yu, In Gyu; Chang, Ki Hyun; Kim, Eui Jong; Kim, Dae Ho

    1997-01-01

    To find and describe the cerebellar arteries arising from the internal carotid artery, explain them embryologically, and evaluate their clinical implication. To determine the point in the internal carotid artery from which the cereballar artery arose anomalously, consecutive angiographic studies performed in the last three years were reviewed. The distribution of such anomalous cerebellar arteries, the point in the internal carotid artery from which the anomalous vessels originated, and associated findings were analyzed. Five anomalous origins of cerebellar arteries arising arising directly from the internal carotid artery were found in five patients. Three anterior inferior cerebellar arteries (AICA) and one common trunk of an AICA and a posterior inferior cerebellar artery (PICA) were found to originate from the internal carotid artery at a point close to the origin of the primitive trigeminal artery. A PICA arose from an artery presenting a course similar to the proatlantal intersegmental artery. Intracranial aneurysms in two patients, Moyamoya disease in one, and facial arteriovenous malformation in one. In our series, AICAs supplied from the arteries considered to be persistent trigeminal artery variants were the most common type. A correlation between type of anomalous cerebellar artery and type of carotid-vertebrobasilar anastomosis may exist. Cerebellar arteries originating anomalously from the internal carotid artery seem to occur as a result of the persistence of carotid-vertebrobasilar anastomoses associated with incomplete fusion of the longitudinal neural arteries. An understanding of these anomalous cerebellar arteries may help prevent accidents during therapeutic embolization and surgical treatment, as well as misinterpretation

  1. Evaluation of the angiographic findings for extrahepatic arterial supply to primary hepatic cancer and interventional therapy

    International Nuclear Information System (INIS)

    Wang Weiyu; Lv Weifu; Hou Changlong; Zhang Xingming; Zhang Zhengfeng; Lu Dong; Gao Zonggen

    2007-01-01

    Objective: To study the angiographic characteristics of extrahepatic arterial supply for primary hepatic cancer (PHC)and the significance of interventional therapy. Methods: 32 cases of primary. hepatic cancer were undertaken routine celiac arterial angiography and explored the extrahepatic arterial supply for the tumor, then followed by superselective transcatheter arterial chemoembolization (TACE). Results: 37 extrahepatic feeding arteries to hepatic cancers in 32 cases were found including 12 from superior mesenteric arteries(SMA), 9 right inferior phrenic arteries (RIPA), 1 left inferior phrenic arteries (LIPA), 2 pancreatic arterial arch, 1 right internal thoracic artery(RITA), 1 right intercostal artery(RICA), 6 left gastric arteries (LGA), 1 splenic artery, 2 omental arteries (OTA), 2 gastroduodenal arteries. The most common extrahepatic feeding arteries were originated from SMA and RIPA. The rest 33 were performed with superselective transcatheter arterial chemoembolization and the other 4 with only transcatheter arterial chemotherapeutic perfusion due to failure of superselective catheterization. Conclusion: The extrahepatic feeding artery is commonly seen with various kinds and also necessary for interventional treatment same as the primary ones for hepatic cancers. (authors)

  2. Ovarian Artery: Angiographic Appearance, Embolization and Relevance to Uterine Fibroid Embolization

    International Nuclear Information System (INIS)

    Pelage, J.P.; Walker, W.J.; Le Dref, O.; Rymer, R.

    2003-01-01

    Purpose: To describe the angiographic appearance of the ovarian artery and its main variations that may be relevant to uterine fibroid embolization. Methods: The flush aortograms of 294 women who had been treated by uterine artery embolization for fibroids were reviewed. Significant arterial supply to the fibroid, and the origin and diameter of identified ovarian arteries were recorded. In patients with additional embolization of the ovarian artery, the follow-up evaluation also included hormonal levels and Doppler imaging of the ovaries. Results: A total of 75 ovarian arteries were identified in 59 women (bilaterally in 16 women and unilaterally in 43 women). All ovarian arteries originated from the aorta below the level of the renal arteries with a characteristic tortuous course. Fifteen women had at least one enlarged ovarian artery supplying the fibroids. Fourteen women (14/15, 93%) presented at least one of the following factors: prior pelvic surgery, tubo-ovarian pathology or large fundal fibroids. Conclusion: We advocate the use of flush aortography in women with prior tubo-ovarian pathology or surgery or in cases of large fundal fibroids. In the case of an ovarian artery supply to the fibroids, superselective catheterization and embolization of the ovarian artery should be considered

  3. Models of genus one curves

    OpenAIRE

    Sadek, Mohammad

    2010-01-01

    In this thesis we give insight into the minimisation problem of genus one curves defined by equations other than Weierstrass equations. We are interested in genus one curves given as double covers of P1, plane cubics, or complete intersections of two quadrics in P3. By minimising such a curve we mean making the invariants associated to its defining equations as small as possible using a suitable change of coordinates. We study the non-uniqueness of minimisations of the genus one curves des...

  4. Differential Clinical Outcomes Between Angiographic Complete Versus Incomplete Coronary Revascularization, According to the Presence of Chronic Kidney Disease in the Drug-Eluting Stent Era.

    Science.gov (United States)

    Kim, Jihoon; Lee, Joo Myung; Choi, Ki Hong; Rhee, Tae-Min; Hwang, Doyeon; Park, Jonghanne; Ahn, Chul; Park, Taek Kyu; Yang, Jeong Hoon; Song, Young Bin; Choi, Jin-Ho; Hahn, Joo-Yong; Choi, Seung-Hyuk; Gwon, Hyeon-Cheol

    2018-02-15

    There are limited data regarding the prognostic impact of angiographic complete revascularization (CR) in patients with chronic kidney disease (CKD). We sought to investigate the differential prognostic impact of angiographic CR over incomplete revascularization (IR), according to the presence of CKD in the drug-eluting stent era. Between 2003 and 2011 at Samsung Medical Center, consecutive patients with multivessel disease were stratified by the presence of CKD (estimated glomerular filtration rate <60 mL/min per 1.73 m 2 ) and classified according to angiographic CR (residual SYNTAX score=0) or IR. Clinical outcomes were compared between angiographic CR and IR, stratified by the presence of CKD. Primary outcome was patient-oriented composite outcomes (POCO, a composite of all-cause death, myocardial infarction, any revascularization) at 3 years. Inverse probability weighting was performed between the CR and IR groups. A total of 3224 patients were eligible for analysis: 2295 without CKD; 929 with CKD. Among non-CKD patients, angiographic CR showed a significantly lower risk of POCO than IR (17.2% versus 21.7%, adjusted hazard ratio 0.76, 95% confidence interval, 0.62-0.95, P =0.014), mainly driven by a significantly lower risk of any revascularization. Among CKD patients, however, angiographic CR was associated with a significantly higher risk of POCO than IR (37.7% versus 28.4%, adjusted hazard ratio 1.42, 95% confidence interval, 1.08%-1.85%, P =0.011), mainly driven by a significantly higher risk of nonfatal target vessel myocardial infarction. Angiographic CR was associated with reduced risk of POCO than IR in patients without CKD; however, it was associated with a significantly higher risk of POCO and nonfatal myocardial infarction in CKD patients. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  5. Direct traumatic carotid cavernous fistula: angiographic classification and treatment strategies. Study of 172 cases.

    Science.gov (United States)

    Chi, Cuong Tran; Nguyen, Dang; Duc, Vo Tan; Chau, Huynh Hong; Son, Vo Tan

    2014-01-01

    We report our experience in treatment of traumatic direct carotid cavernous fistula (CCF) via endovascular intervention. We hereof recommend an additional classification system for type A CCF and suggest respective treatment strategies. Only type A CCF patients (Barrow's classification) would be recruited for the study. Based on the angiographic characteristics of the CCF, we classified type A CCF into three subtypes including small size, medium size and large size fistula depending on whether there was presence of the anterior carotid artery (ACA) and/or middle carotid artery (MCA). Angiograms with opacification of both ACA and MCA were categorized as small size fistula. Angiograms with opacification of either ACA or MCA were categorized as medium size fistula and those without opacification of neither ACA nor MCA were classified as large size fiatula. After the confirm angiogram, endovascular embolization would be performed impromptu using detachable balloon, coils or both. All cases were followed up for complication and effect after the embolization. A total of 172 direct traumatic CCF patients were enrolled. The small size fistula was accountant for 12.8% (22 cases), medium size 35.5% (61 cases) and large size fistula accountant for 51.7% (89 cases). The successful rate of fistula occlusion under endovascular embolization was 94% with preservation of the carotid artery in 70%. For the treatment of each subtype, a total of 21/22 cases of the small size fistulas were successfully treated using coils alone. The other single case of small fistula was defaulted. Most of the medium and large size fistulas were cured using detachable balloons. When the fistula sealing could not be obtained using detachable balloon, coils were added to affirm the embolization of the cavernous sinus via venous access. There were about 2.9% of patient experienced direct carotid artery puncture and 0.6% puncture after carotid artery cut-down exposure. About 30% of cases experienced

  6. Background Complex angiographic lesions and clinic presentation in unstable angina. A prospective study

    International Nuclear Information System (INIS)

    LLuberas, R.; Mallo, D.; Pouso, J.; Artucio, C.; Korytnicki; Argon, L.; Besada, E.; Tavella, N.

    2002-01-01

    Background Complex angiography lesions and intracoronary thrombus have been identified in unstable angina.Braunwalds categorization has been accepted in the last years.Identifying severe clinical classes class III (angina at rest during the last 48 hours), class C (angina postinfarction) and class c (angina with maximum therapeutic). The main objective of this study was to determine independent associations of Braunwalds classes III, C and c: complex lesions, intracoronary thrombus, total occlusion and distal flux TIMI<3 of the responsible vessel. The secondary objectives were to analyze the angiographic features of the lesion and the responsible vessel. Aprospective study of 300 patients with diagnosed unstable angina, clustered according to Braunwalds clinis classification was done. The angiographic evaluation was performed identifying the responsible lesion and the presence of the complex lesion, intracoronary thrombus, total occlusion and distal flux TIMI<3 of the responsible vessel. A univariate analysis and a multivariate model of binary logistic regression were used. In the 300 patient population, 22 patients with normal coronaries(7.3%) were identified. The responsible lesion was identified in 243 out of the remaining 278 patients (87,4%). Class III was significantly associated with the complex lesion (OR=2.74, IC95%=1,27-5,9) and intracoronary thrombus (OR=2,82 IC95=1,2-6,6). Class C was significantly associated with intracoronary thrombus (OR=3.9),IC95%=1.53-10,0).Class III was and independent predictor for the presence of the complex lesion(OR=1.98, IC 95%=1,01-3,87) and intracoronary thrombus (OR=2,47 IC95%=1,14-5,37). Class C was and independent predictor for the complex lesion (OR=5,05,IC95%=2.25-11,3), infracoronary thrombus (OR=8,04, IC 95%=3,49-18,0), total occlusion (OR=6,49, IC95%=2,67-15,7) and distal flux TIMI<3(OR=3,96,IC 95%=1,87-8,4) There was no significant association between classes III, C and c and the responsible vessel, localization of

  7. Quantum fields in curved space

    International Nuclear Information System (INIS)

    Birrell, N.D.; Davies, P.C.W.

    1982-01-01

    The book presents a comprehensive review of the subject of gravitational effects in quantum field theory. Quantum field theory in Minkowski space, quantum field theory in curved spacetime, flat spacetime examples, curved spacetime examples, stress-tensor renormalization, applications of renormalization techniques, quantum black holes and interacting fields are all discussed in detail. (U.K.)

  8. MYOCARDIAL BRIDGING - CLINICAL AND ANGIOGRAPHIC PROFILE IN LAST 5 YEARS; A STUDY OF 129 CASES

    Directory of Open Access Journals (Sweden)

    Abhilash S P

    2010-11-01

    Full Text Available Aims of study : To assess the clinical and angiographical profile of myocardial bridging from consecutive coronary angiograms done over last 5 years at Medical college, Thiruvananthapuram. To assess the risk of cardiovascular events and the risk of accelerated atherosclerosis in isolated myocardial bridging. Methods : Consecutive coronary angiograms done at Medical college Thiruvananthapuram from 04/02/2005 to 31/03/2010 were reviewed for myocardial bridging. A total of 10492 coronary angiograms were reviewed. Myocardial bridges with systolic lumen reduction of more than 50% were considered for analysis. Quantitative coronary angiography (QCA was used for analysis. Clinical presentation as well as correlation with structural heart disease and coronary heart disease was assessed. Results: Incidence of myocardial bridges was 1.23%. Of the 129 patients with myocardial bridges 63 ( 48.8% had associated significant coronary artery disease. Remaining 66 (51.2% patients presented with isolated bridges. Out of these 66 patients with isolated myocardial bridges, 7 (10.6% patients presented with acute myocardial infarction and 3 (4.5% presented with cardiac arrhythmias. Of the 63 patients with significant coronary disease 11 (17.5% patients had single vessel disease and they had the culprit lesion and myocardial bridge seen in the same vessel. Most common location of myocardial bridge was mid LAD (64.9% followed by distal LAD (23.8%. Length of bridge was 20 mm in 35.7%. Mean percentage of systolic obliteration by the bridge was 74.5%. 100% systolic obliteration was seen in 7.79% of isolated bridges and in 9.79% of bridges with CAD. Among 120 rhuematic heart disease patients who underwent coronary angiogram, 10 (8.3% patients had myocardial bridging. 12.1% of all HCM patients who underwent coronary angiograms had myocardial bridging. Conclusion: Myocardial bridging can be lethal- can accelerate atherosclerosis, can precipitate acute MIs and life

  9. Carotid Angioplasty In Octogenarians: A Mono-Arm Trial With Clinical And Angiographic Follow Up

    Directory of Open Access Journals (Sweden)

    Ehsan Sharifipour

    2017-02-01

    Full Text Available Background: Octogenarians account for a third of ischemic stroke (IS patients and they have higher morbidity and mortality rate among IS patients. The aim of this study was to evaluate the pri-procedural and long term clinical and angiographic statement of carotid artery angioplasty (CAA in octogenarians. Methods: In a mono-arm trial 102 patients>80 years old with symptomatic internal carotid artery (ICA stenosis presented by non-disabling IS or TIA underwent the CAA and were evaluated prospectively from January 2010 to July 2014. All patients had standard stroke care during the study follow up. The peri-procedural complications, cerebrovascular accidents, restenosis in target vessel and mortality rate were recorded to evaluate safety and durability of this secondary stroke prevention method in octogenarians. Results: 48 (47.06% males and 54 (52.9% females in a mean period of 24.5±14.1 (6-50 months were followed. For all patients mean age was 83.39 ±2.53 (range, 80-88 years. The success rate of CAA was 100%, whereas the peri-procedural complication rate was 5.8% (access-site local hematoma and bradycardia during CAA both in 2.94%.There was only one patient who had acute ischemic stroke during the procedure. Restenosis occurred in 3.9% after a mean of 21.5 months. The proportion of recurrent cerebrovascular accident was 9.8% while TIAs occurred in 3.9% and stroke in 1% of patients. Also 4.9% of patients experienced coronary artery disease and the proportion of fatal recurrent cerebrovascular accident was 2.9%.  The median patient event-free survival was 20 months. Conclusion: CAA seems to be a safe and durable IS secondary prevention method in octogenarians with symptomatic carotid artery stenosis.

  10. Renal artery origins and variations: angiographic evaluation of 855 consecutive patients.

    Science.gov (United States)

    Ozkan, Uğur; Oğuzkurt, Levent; Tercan, Fahri; Kizilkiliç, Osman; Koç, Zafer; Koca, Nihal

    2006-12-01

    To determine angiographically the origins and variations of renal arteries. The study included 855 consecutive patients (163 females, 692 males; mean age, 61 years) living in the Cukurova region of Turkey, who underwent either aortofemoropopliteal (AFP) angiography for the investigation of peripheral arterial disease, or renal angiography for renovascular hypertension, and were prospectively evaluated. Renal arteries were visualized by non-selective catheterization during AFP angiography and by selective or non-selective catheterization during renal angiography. Locations of renal artery origins and renal artery variations, including the presence of extra renal arteries and division patterns were analyzed on angiograms. The origin of main renal arteries off the aorta was between the upper margin of L1 and lower margin of L2 vertebra in 98% of the patients, and in 74%, this was the origin of extra renal arteries. The most common location for renal artery origin was the L1-L2 intervertebral disc level. A single renal artery was present in both kidneys in 76% of patients. Renal artery variations included multiple arteries in 24%, bilateral multiple arteries in 5%, and early division in 8% of the cases. Additional renal arteries on the right side were found in 16% and on the left side in 13% of cases. Of all the extra renal arteries, the percentage of accessory and aberrant renal arteries were 49% and 51%, respectively. Renal arteries originated between the first and the second lumbar vertebral levels in most patients. Extra renal arteries were quite frequent. These results should be kept in mind when a non-invasive diagnostic search is performed for renal artery stenosis, or when renal surgery related to renal arteries is performed.

  11. Klippel-Trenaunay syndrome: the angiographic manifestations and endovascular treatment with pingyangmycin-lipiodol emulsion

    International Nuclear Information System (INIS)

    Kong Weidong; Li Yanhao; He Xiaofeng; Chen Yong; Zeng Qingle; Zhao Jianbo

    2004-01-01

    Objective: To observe the angiographic manifestations of Klippel-Trenaunay syndrome (KTS) and to treat it by intra-arterial injection of pingyangmycin-lipiodol emulsion (PLE). Methods: Seven young patients (age range 12-19 years, mean 15.2 years) with KTS in the single low limb were examined by arteriography. Then, PLE (mixed with pingyangmycin 6-12 mg, lipiodol 4-8 ml) was injected by transcatheter into the femoral artery. The effects, side-effects, and complications of the therapy were observed. Results: The arteriography revealed a few distended small arteries with staining of venous sinus of different size in the soft tissue (5/7), as well as drainage vein enlargement (4/7) and superficial varicose vein (5/7). PLE deposited visibly in the abnormal sinus except one case. During 13-30 months' follow-up, 6 cases had good effects on limb hypertrophy after the treatment, and the limbs with lesions were obviously shrank and the thigh circumference became near to the normal limb. Another case had no obvious change. One had mild recurring around the knee one year later. The major side-effects included medium to extreme swelling of the limbs (7/7), serum transaminase elevation (2/7), and numbness of the distal end of the limb (1/7). The complications included a small piece of skin necrosis (1/7) and the first toe-drop (1/7). Conclusion: The arteriography in KTS can demonstrate a part of vascular malformations. Transcatheter intra-arterial PLE injection was effective in treating the hypertrophy of the limb caused by KTS. Because the therapy could result in some serious side-effects and complications, it should be used carefully

  12. Cerebellar hemangioblastomas with computed tomographic, angiographic, and positron-emission tomographic evaluations

    International Nuclear Information System (INIS)

    Kikuchi, Kenji; Sakamoto, Tetsuya; Kowada, Masayoshi; Tamakawa, Yoshiharu; Uemura, Kazuo.

    1986-01-01

    Ten patients with cerebellar hemangioblastomas were reviewed, and evaluations were made by computed tomography (CT), vertebral angiography, and positron-emission tomography (PET). Cerebellar hemangioblastomas were classified into three types on the basis of their CT appearances: Type I: a cystic tumor without a demonstrable mural nodule; Type II: a cystic tumor with a mural nodule, and Type III: a solid tumor without any cyst formation. All of the cystic tumors classified here as Types I and II were associated with a shift and deformity of the fourth ventricule and an enlarged lateral ventricle, and yet no low-density area in the adjacent cerebellar tissue indicating perifocal edema was demonstrated. By contrast, in the solid hemangioblastomas designated as Type III, finger-shaped, low-density areas were visualized around the enhancing mass lesion, extending to the white matter of the entire affected cerebellar hemisphere. The vertebral angiographic classification of cerebellar hemangioblastomas was also attempted as follows: Type I: an avascular tumor without a demonstrable mural nodule; Type II: an avascular tumor with a mural nodule, and Type III: a solid vascular tumor with enlarged feeding arteries and distinct draining veins. In Type II, a relatively small mural nodule was visualized, fed mostly by a single feeding artery, and the tumor stain was at its peak at the arterial phase. No draining vein was opacified in most cases. In contrast, solid tumors classified as Type III were demonstrated to be hypervascular tumors with a multiplicity of feeding arteries and draining veins. The vascular mass remained to be opacified through the venous phase with delayed blood circulation. PET was performed on a 31-year-old male with a solid hemangioblastoma. (J.P.N)

  13. Plasma Tissue Factor Pathway Inhibitor Levels in Angiographically Defined Coronary Artery Disease Among Saudis

    Directory of Open Access Journals (Sweden)

    Syed Shahid Habib

    2013-05-01

    Full Text Available Objectives: This study was aimed to determine plasma levels of total (TFPI-T and free (TFPI-F tissue factor pathway inhibitor, plasminogen activator inhibitor-1 (PAI-1, and tissue plasminogen activator (t-PA in a cohort of Saudi patients with chronic stable angiographically defined coronary artery disease (CAD and to determine its correlation with its severity.Methods: This cross sectional study was conducted in the department of physiology and department of cardiology, College of Medicine, and King Khalid University Hospital and King Saud University, Riyadh. Sixty known cases of CAD who had undergone angiography (35 males and 25 females were selected. A control group included 39 (20 males and 19 females healthy subjects. Fasting venous blood samples were analyzed for total (TFPI-T and free (TFPI-F tissue factor pathway inhibitor, plasminogen activator inhibitor-1 (PAI-1, and tissue plasminogen activator (t-PA. Gensini scores and vessel scores were determined for assessing CAD severity.Results: There were non-significant differences between age, body mass index (BMI and Blood pressure between the controls and CAD subjects. A comparison of hemostatic markers between control and CAD patients showed significantly higher levels of Fibrinogen, PAI-1, TFPI-T and TFPI-F in CAD patients compared to control subjects. But there was no difference in plasma t-PA levels. TFPI-T had a significant positive correlation with severity of disease determined by Gensini Scores (r=0.344; p=0.006 and vessel scores (r=0.338; p=0.015.Conclusion: Plasma levels of total tissue factor pathway inhibitor are significantly related with the presence and severity of CAD. Elevated levels of TFPI-T may be considered as useful diagnostic and prognostic markers in patients with CAD.

  14. Interventional spinal procedures guided and controlled by a 3D rotational angiographic unit.

    Science.gov (United States)

    Pedicelli, Alessandro; Verdolotti, Tommaso; Pompucci, Angelo; Desiderio, Flora; D'Argento, Francesco; Colosimo, Cesare; Bonomo, Lorenzo

    2011-12-01

    The aim of this paper is to demonstrate the usefulness of 2D multiplanar reformatting images (MPR) obtained from rotational acquisitions with cone-beam computed tomography technology during percutaneous extra-vascular spinal procedures performed in the angiography suite. We used a 3D rotational angiographic unit with a flat panel detector. MPR images were obtained from a rotational acquisition of 8 s (240 images at 30 fps), tube rotation of 180° and after post-processing of 5 s by a local work-station. Multislice CT (MSCT) is the best guidance system for spinal approaches permitting direct tomographic visualization of each spinal structure. Many operators, however, are trained with fluoroscopy, it is less expensive, allows real-time guidance, and in many centers the angiography suite is more frequently available for percutaneous procedures. We present our 6-year experience in fluoroscopy-guided spinal procedures, which were performed under different conditions using MPR images. We illustrate cases of vertebroplasty, epidural injections, selective foraminal nerve root block, facet block, percutaneous treatment of disc herniation and spine biopsy, all performed with the help of MPR images for guidance and control in the event of difficult or anatomically complex access. The integrated use of "CT-like" MPR images allows the execution of spinal procedures under fluoroscopy guidance alone in all cases of dorso-lumbar access, with evident limitation of risks and complications, and without need for recourse to MSCT guidance, thus eliminating CT-room time (often bearing high diagnostic charges), and avoiding organizational problems for procedures that need, for example, combined use of a C-arm in the CT room.

  15. Interventional spinal procedures guided and controlled by a 3D rotational angiographic unit

    International Nuclear Information System (INIS)

    Pedicelli, Alessandro; Verdolotti, Tommaso; Desiderio, Flora; D'Argento, Francesco; Colosimo, Cesare; Bonomo, Lorenzo; Pompucci, Angelo

    2011-01-01

    The aim of this paper is to demonstrate the usefulness of 2D multiplanar reformatting images (MPR) obtained from rotational acquisitions with cone-beam computed tomography technology during percutaneous extra-vascular spinal procedures performed in the angiography suite. We used a 3D rotational angiographic unit with a flat panel detector. MPR images were obtained from a rotational acquisition of 8 s (240 images at 30 fps), tube rotation of 180 and after post-processing of 5 s by a local work-station. Multislice CT (MSCT) is the best guidance system for spinal approaches permitting direct tomographic visualization of each spinal structure. Many operators, however, are trained with fluoroscopy, it is less expensive, allows real-time guidance, and in many centers the angiography suite is more frequently available for percutaneous procedures. We present our 6-year experience in fluoroscopy-guided spinal procedures, which were performed under different conditions using MPR images. We illustrate cases of vertebroplasty, epidural injections, selective foraminal nerve root block, facet block, percutaneous treatment of disc herniation and spine biopsy, all performed with the help of MPR images for guidance and control in the event of difficult or anatomically complex access. The integrated use of ''CT-like'' MPR images allows the execution of spinal procedures under fluoroscopy guidance alone in all cases of dorso-lumbar access, with evident limitation of risks and complications, and without need for recourse to MSCT guidance, thus eliminating CT-room time (often bearing high diagnostic charges), and avoiding organizational problems for procedures that need, for example, combined use of a C-arm in the CT room. (orig.)

  16. Interventional spinal procedures guided and controlled by a 3D rotational angiographic unit

    Energy Technology Data Exchange (ETDEWEB)

    Pedicelli, Alessandro; Verdolotti, Tommaso; Desiderio, Flora; D' Argento, Francesco; Colosimo, Cesare; Bonomo, Lorenzo [Catholic University of Rome, A. Gemelli Hospital, Department of Bioimaging and Radiological Sciences, Rome (Italy); Pompucci, Angelo [Catholic University of Rome, A. Gemelli Hospital, Department of Neurotraumatology, Rome (Italy)

    2011-12-15

    The aim of this paper is to demonstrate the usefulness of 2D multiplanar reformatting images (MPR) obtained from rotational acquisitions with cone-beam computed tomography technology during percutaneous extra-vascular spinal procedures performed in the angiography suite. We used a 3D rotational angiographic unit with a flat panel detector. MPR images were obtained from a rotational acquisition of 8 s (240 images at 30 fps), tube rotation of 180 and after post-processing of 5 s by a local work-station. Multislice CT (MSCT) is the best guidance system for spinal approaches permitting direct tomographic visualization of each spinal structure. Many operators, however, are trained with fluoroscopy, it is less expensive, allows real-time guidance, and in many centers the angiography suite is more frequently available for percutaneous procedures. We present our 6-year experience in fluoroscopy-guided spinal procedures, which were performed under different conditions using MPR images. We illustrate cases of vertebroplasty, epidural injections, selective foraminal nerve root block, facet block, percutaneous treatment of disc herniation and spine biopsy, all performed with the help of MPR images for guidance and control in the event of difficult or anatomically complex access. The integrated use of ''CT-like'' MPR images allows the execution of spinal procedures under fluoroscopy guidance alone in all cases of dorso-lumbar access, with evident limitation of risks and complications, and without need for recourse to MSCT guidance, thus eliminating CT-room time (often bearing high diagnostic charges), and avoiding organizational problems for procedures that need, for example, combined use of a C-arm in the CT room. (orig.)

  17. Extended analysis of cooling curves

    International Nuclear Information System (INIS)

    Djurdjevic, M.B.; Kierkus, W.T.; Liliac, R.E.; Sokolowski, J.H.

    2002-01-01

    Thermal Analysis (TA) is the measurement of changes in a physical property of a material that is heated through a phase transformation temperature range. The temperature changes in the material are recorded as a function of the heating or cooling time in such a manner that allows for the detection of phase transformations. In order to increase accuracy, characteristic points on the cooling curve have been identified using the first derivative curve plotted versus time. In this paper, an alternative approach to the analysis of the cooling curve has been proposed. The first derivative curve has been plotted versus temperature and all characteristic points have been identified with the same accuracy achieved using the traditional method. The new cooling curve analysis also enables the Dendrite Coherency Point (DCP) to be detected using only one thermocouple. (author)

  18. The value of regional wall motion abnormalities on 99Tcm-MIBI gated cardiac SPECT in predicting angiographic stenoses of coronary artery

    International Nuclear Information System (INIS)

    Li Dianfu; Huang Jun; Zhu Tiebing; Wang Liansheng; Yang Zhijian; Feng Jianlin; Li Jianhua; Chen Jianwei; Chang Guojun

    2004-01-01

    Objective: To determine the magnitude of angiographic stenoses of coronary artery in reversible regional wall motion abnormalities (RWMA) present in exercise stress 99 Tc m -methoxyisobutylisonitrile (MIBI) gated SPECT myocardial perfusion imaging (MPI). Methods: One hundred and sixteen patients undergoing coronary angiography two weeks before and after the exercise stress 99 Tc m -MIBI gated SPECT MPI. Images were acquired 15 to 20 min after stress. A five grades and twenty segments marking system was introduced to assess the RWMA and thickening of left ventricles. Results: The sensitivity of reversible RWMA for detecting ≥75% angiographic stenoses was 65%, with a specificity of 97%. Reversible RWMA has a high positive predictive value (98%) for stratification between severe angiographic stenoses of 75% and non-severe stenoses (less than 75%). Multivariate analysis showed that the post-stress wall motion (SSSWM), exercise wall motion differentiation value (SDSWM) and summed stress score (SSS) were the independent risk factor of coronary artery jeopardy score. Conclusions: Reversible RWMA, as shown by exercise stress 99 Tc m -MIBI gated SPECT MPI, is a significant predictor of angiographic disease with very high specificity and positive predictive values. Exercise reversible RWMA can rise the assessment value of angiographic severity in MPI

  19. Diagnostic accuracy of unenhanced, contrast-enhanced perfusion and angiographic MRI sequences for pulmonary embolism diagnosis: results of independent sequence readings

    Energy Technology Data Exchange (ETDEWEB)

    Revel, Marie Pierre [Hopital Europeen Georges Pompidou, APHP, Departments of Radiology, Paris (France); Universite Paris Descartes Sorbonne Paris Cite, Paris (France); Hotel-Dieu, Service de Radiologie, Paris (France); Sanchez, Olivier; Meyer, Guy [Hopital Europeen Georges Pompidou, APHP, Respiratory and intensive care and, Paris (France); Universite Paris Descartes Sorbonne Paris Cite, Paris (France); INSERM Unite 765, Paris (France); Lefort, Catherine; Couchon, Sophie; Hernigou, Anne; Frija, Guy [Hopital Europeen Georges Pompidou, APHP, Departments of Radiology, Paris (France); Niarra, Ralph [Hopital Europeen Georges Pompidou, APHP, Clinical Epidemiology, Paris (France); Universite Paris Descartes Sorbonne Paris Cite, Paris (France); Chatellier, Gilles [Hopital Europeen Georges Pompidou, APHP, Clinical Epidemiology, Paris (France); Universite Paris Descartes Sorbonne Paris Cite, Paris (France); INSERM CIC-EC E4, Paris (France)

    2013-09-15

    To independently evaluate unenhanced, contrast-enhanced perfusion and angiographic MR sequences for pulmonary embolism (PE) diagnosis. Prospective investigation, including 274 patients who underwent perfusion, unenhanced 2D steady-state-free-precession (SSFP) and contrast-enhanced 3D angiographic MR sequences on a 1.5-T unit, in addition to CTA (CT angiography). Two independent readers evaluated each sequence independently in random order. Sensitivity, specificity, predictive values and inter-reader agreement were calculated for each sequence, excluding sequences judged inconclusive. Sensitivity was also calculated according to PE location. Contrast-enhanced angiographic sequences showed the highest sensitivity (82.9 and 89.7 %, reader 1 and reader 2, respectively), specificity (98.5 and 100 %) and agreement (kappa value 0.77). Unenhanced angiographic sequences, although less sensitive overall (68.7 and 76.4 %), were sensitive for the detection of proximal PE (92.7 and 100 %) and showed high specificity (96.1 and 99.1 %) and good agreement (kappa value 0.62). Perfusion sequences showed lower sensitivity (75.0 and 79.3 %), specificity (84.8 and 89.7 %) and agreement (kappa value 0.51), and a negative predictive value of 84.8 % at best. Compared with contrast-enhanced angiographic sequences, unenhanced sequences demonstrate lower sensitivity, except for proximal PE, but high specificity and agreement. The negative predictive value of perfusion sequences was insufficient to safely rule out PE. (orig.)

  20. Bronchial and non-bronchial systemic arteries: value of multidetector CT angiography in diagnosis and angiographic embolisation feasibility analysis

    International Nuclear Information System (INIS)

    Lin, Yuning; Chen, Ziqian; Yang, Xizhang; Zhong, Qun; Zhang, Hongwen; Yang, Li; Xu, Shangwen; Li, Hui

    2013-01-01

    The aim of this study is to evaluate the diagnostic performance of multidetector CT angiography (CTA) in depicting bronchial and non-bronchial systemic arteries in patients with haemoptysis and to assess whether this modality helps determine the feasibility of angiographic embolisation. Fifty-two patients with haemoptysis between January 2010 and July 2011 underwent both preoperative multidetector CTA and digital subtraction angiography (DSA) imaging. Diagnostic performance of CTA in depicting arteries causing haemoptysis was assessed on a per-patient and a per-artery basis. The feasibility of the endovascular treatment evaluated by CTA was analysed. Sensitivity, specificity, and positive and negative predictive values for those analyses were determined. Fifty patients were included in the artery-presence-number analysis. In the per-patient analysis, neither CTA (P=0.25) nor DSA (P=1.00) showed statistical difference in the detection of arteries causing haemoptysis. The sensitivity, specificity, and positive and negative predictive values were 94%, 100%, 100%, and 40%, respectively, for the presence of pathologic arteries evaluated by CTA, and 98%, 100%, 100%, and 67%, respectively, for DSA. On the per-artery basis, CTA correctly identified 97% (107/110). Fifty-two patients were included in the feasibility analysis. The performance of CTA in predicting the feasibility of angiographic embolisation was not statistically different from the treatment performed (P=1.00). The sensitivity, specificity, and positive and negative predictive values were 96%, 80%, 98% and 67%, respectively, for CTA. Multidetector CTA is an accurate imaging method in depicting the presence and number of arteries causing haemoptysis. This modality is also useful for determining the feasibility of angiographic embolisation for haemoptysis.

  1. Bronchial and non-bronchial systemic arteries: value of multidetector CT angiography in diagnosis and angiographic embolisation feasibility analysis.

    Science.gov (United States)

    Lin, Yuning; Chen, Ziqian; Yang, Xizhang; Zhong, Qun; Zhang, Hongwen; Yang, Li; Xu, Shangwen; Li, Hui

    2013-12-01

    The aim of this study is to evaluate the diagnostic performance of multidetector CT angiography (CTA) in depicting bronchial and non-bronchial systemic arteries in patients with haemoptysis and to assess whether this modality helps determine the feasibility of angiographic embolisation. Fifty-two patients with haemoptysis between January 2010 and July 2011 underwent both preoperative multidetector CTA and digital subtraction angiography (DSA) imaging. Diagnostic performance of CTA in depicting arteries causing haemoptysis was assessed on a per-patient and a per-artery basis. The feasibility of the endovascular treatment evaluated by CTA was analysed. Sensitivity, specificity, and positive and negative predictive values for those analyses were determined. Fifty patients were included in the artery-presence-number analysis. In the per-patient analysis, neither CTA (P = 0.25) nor DSA (P = 1.00) showed statistical difference in the detection of arteries causing haemoptysis. The sensitivity, specificity, and positive and negative predictive values were 94%, 100%, 100%, and 40%, respectively, for the presence of pathologic arteries evaluated by CTA, and 98%, 100%, 100%, and 67%, respectively, for DSA. On the per-artery basis, CTA correctly identified 97% (107/110). Fifty-two patients were included in the feasibility analysis. The performance of CTA in predicting the feasibility of angiographic embolisation was not statistically different from the treatment performed (P = 1.00). The sensitivity, specificity, and positive and negative predictive values were 96%, 80%, 98% and 67%, respectively, for CTA. Multidetector CTA is an accurate imaging method in depicting the presence and number of arteries causing haemoptysis. This modality is also useful for determining the feasibility of angiographic embolisation for haemoptysis. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

  2. Registration of angiographic image on real-time fluoroscopic image for image-guided percutaneous coronary intervention.

    Science.gov (United States)

    Kim, Dongkue; Park, Sangsoo; Jeong, Myung Ho; Ryu, Jeha

    2018-02-01

    In percutaneous coronary intervention (PCI), cardiologists must study two different X-ray image sources: a fluoroscopic image and an angiogram. Manipulating a guidewire while alternately monitoring the two separate images on separate screens requires a deep understanding of the anatomy of coronary vessels and substantial training. We propose 2D/2D spatiotemporal image registration of the two images in a single image in order to provide cardiologists with enhanced visual guidance in PCI. The proposed 2D/2D spatiotemporal registration method uses a cross-correlation of two ECG series in each image to temporally synchronize two separate images and register an angiographic image onto the fluoroscopic image. A guidewire centerline is then extracted from the fluoroscopic image in real time, and the alignment of the centerline with vessel outlines of the chosen angiographic image is optimized using the iterative closest point algorithm for spatial registration. A proof-of-concept evaluation with a phantom coronary vessel model with engineering students showed an error reduction rate greater than 74% on wrong insertion to nontarget branches compared to the non-registration method and more than 47% reduction in the task completion time in performing guidewire manipulation for very difficult tasks. Evaluation with a small number of experienced doctors shows a potentially significant reduction in both task completion time and error rate for difficult tasks. The total registration time with real procedure X-ray (angiographic and fluoroscopic) images takes [Formula: see text] 60 ms, which is within the fluoroscopic image acquisition rate of 15 Hz. By providing cardiologists with better visual guidance in PCI, the proposed spatiotemporal image registration method is shown to be useful in advancing the guidewire to the coronary vessel branches, especially those difficult to insert into.

  3. Dipyridamole-induced ST segment depression during thallium-201 imaging in patients with coronary artery disease: angiographic and hemodynamic determinants

    International Nuclear Information System (INIS)

    Chambers, C.E.; Brown, K.A.

    1988-01-01

    To examine the angiographic and hemodynamic determinants of dipyridamole-induced ST segment depression in patients with coronary artery disease, 41 patients with angiographically documented coronary disease who underwent dipyridamole-thallium-201 myocardial scintigraphy were studied. Dipyridamole-induced ST depression occurred in 14 (34%) of the 41 patients. Stepwise multivariate logistic regression was performed to compare the predictive value of angiographic findings (good coronary collateral vessels, jeopardized collateral vessels, multivessel disease), hemodynamic changes (changes in heart rate, systolic pressure, diastolic pressure and rate-pressure product), thallium-201 results (perfusion defect, thallium-201 redistribution) and demographic data (age, gender, medications). Only the presence of good coronary collateral vessels (p less than 0.02) and increases in rate-pressure product after dipyridamole infusion (p less than 0.02) were significant multivariate predictors of dipyridamole-induced ST depression. Good collateral vessels were more common in the group with ST depression (11 [79%] of 14) than they were in the group without ST depression (6 [22%] of 27; p less than 0.001). Rate-pressure product increased 2,835 +/- 1,648 beats/min.mm Hg in the group with ST depression compared with 1,179 +/- 1,417 beats/min.mm Hg in patients without ST depression (p less than 0.005). In conclusion, dipyridamole-induced ST segment depression in patients with coronary artery disease appears to be related to 1) the presence of good coronary collateral vessels, which may act by facilitating coronary steal, and 2) increases in rate-pressure product, reflecting increased myocardial oxygen demand. These observations may explain the lack of prognostic value of dipyridamole-induced ST segment depression described in previous reports

  4. A study of low-density areas, clinical findings, and angiographic findings in patients with cerebral infarction

    International Nuclear Information System (INIS)

    Saiki, Iwao; Sakai, Yoshiaki; Oikawa, Tadato; Koide, Kohji; Kanaya, Haruyuki.

    1978-01-01

    55 out of 62 patients with cerebral infarction were investigated in terms of CT scan findings, angiographic findings, and clinical symptoms. The results obtained were as follows: 1) The low-density areas of the CT scan findings were classified into the following four types: large hemispheric or lobular --Type I; wedge-shaped --Type II; small --Type III; and lacunar low-density area. --Type IV. 2) Almost all patients with angiographically occlusive findings showed low-density areas of Type I; however, one patient with ICA occlusion revealed only a lacunar low-density area. 3) The patients with lacunar low-density areas showed an angiographically delayed filling of the angular artery and posterior parietal artery of the middle cerebral artery. 4) The relationship between the types of low-density areas and the clinical conscious disorders was not clear. On the other hand, the patients with Type I low-density areas almost all had motor disturbances, while patients with other types of low-density areas showed only 60 - 70% motor disturbances. 5) In patients with speech disorders, total aphasia cases were found in patients with large hemispheric low-density areas on the left side. Although, motor aphasia cases were seen in patients with various low-density areas on the left inferior frontal and precentral gyri, dysarthria cases were found in the patients with several low-density areas on both sides. 6) The localization of lacunar low-density areas seemed to be near the caudate nucleus on the right side and in the putaminal regions on the left side. The mean and the standard deviation of CT numbers in the lacunar low-density areas showed higher values on the right side than on the left side. (author)

  5. Relationship of myocardial hibernation, scar, and angiographic collateral flow in ischemic cardiomyopathy with coronary chronic total occlusion.

    Science.gov (United States)

    Wang, Li; Lu, Min-Jie; Feng, Lei; Wang, Juan; Fang, Wei; He, Zuo-Xiang; Dou, Ke-Fei; Zhao, Shi-Hua; Yang, Min-Fu

    2018-03-07

    The relationship between myocardial viability and angiographic collateral flow is not fully elucidated in ischemic cardiomyopathy (ICM) with coronary artery chronic total occlusion (CTO). We aimed to clarify the relationship between myocardial hibernation, myocardial scar, and angiographic collateral flow in these patients. Seventy-one consecutive ICM patients with 122 CTOs and 652 dysfunctional segments within CTO territories were retrospectively analyzed. Myocardial hibernation (perfusion-metabolism mismatch) and the extent of 18 F-fluorodeoxyglucose (FDG) abnormalities were assessed using 99m Tc-sestamibi and 18 F-FDG imaging. Myocardial scar was evaluated by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging. Collateral flow observed on coronary angiography was assessed using Rentrop classification. In these patients, neither the extent nor frequency of myocardial hibernation or scar was related to the status of collateral flow. Moreover, the matching rate in determining myocardial viability was poor between any 2 imaging indices. The extent of 18 F-FDG abnormalities was linearly related to the extent of LGE rather than myocardial hibernation. Of note, nearly one-third (30.4%) of segments with transmural scar still had hibernating tissue. Hibernation and non-transmural scar had higher sensitivity (63.0% and 66.7%) than collateral flow (37.0%) in predicting global functional improvement. Angiographic collateral cannot accurately predict myocardial viability, and has lower sensitivity in prediction of functional improvement in CTO territories in ICM patients. Hence, assessment of myocardial viability with non-invasive imaging modalities is of importance. Moreover, due to the lack of correlation between myocardial hibernation and scar, these two indices are complementary but not interchangeable.

  6. Chest pain in patients with arterial hypertension, angiographically normal coronary arteries and stiff aorta: the aortic pain syndrome.

    Science.gov (United States)

    Stakos, Dimitrios A; Tziakas, Dimitrios N; Chalikias, George; Mitrousi, Konstantina; Tsigalou, Christina; Boudoulas, Harisios

    2013-01-01

    Arterial hypertension is often associated with a stiff aorta as a result of collagen accumulation in the aortic wall and may produce chest pain. In the present study, possible interrelationships between aortic function, collagen turnover and exercise-induced chest pain in patients with arterial hypertension and angiographically normal coronary arteries were investigated. Ninety-seven patients with arterial hypertension, angiographically normal coronary arteries and no evidence of myocardial ischemia on nuclear cardiac imaging during exercise test were studied. Of these, 43 developed chest pain during exercise (chest pain group) while 54 did not (no chest pain group). Carotid femoral pulse-wave velocity (PWVc-f) was used to assess the elastic properties of the aorta. Amino-terminal pro-peptides of pro-collagen type I, (PINP, reflecting collagen synthesis), serum telopeptides of collagen type I (CITP, reflecting collagen degradation), pro-metalloproteinase 1 (ProMMP-1), and tissue inhibitor of metalloproteinase 1 (TIMP-1, related to collagen turnover) were measured in plasma by immunoassay. The chest pain group had higher PWVc-f, higher and /CITP ratio, and lower proMMP-1/ TIMP-1 ratio compared to the no chest pain group. PWVc-f (t=2.53, p=0.02) and PINP (t=2.42, p=0.02) were independently associated with the presence of chest pain in multiple regression analysis. Patients with arterial hypertension, exercise-induced chest pain and angiographically normal coronary arteries, without evidence of exercise-induced myocardial ischemia, had a stiffer aorta compared to those without chest pain. Alterations in collagen type I turnover that favor collagen accumulation in the aortic wall may contribute to aortic stiffening and chest pain in these patients.

  7. Angiographic analysis of animal model aneurysms treated with novel polyurethane asymmetric vascular stent (P-AVS): feasibility study.

    Science.gov (United States)

    Ionita, Ciprian N; Dohatcu, Andreea; Sinelnikov, Andrey; Sherman, Jason; Keleshis, Christos; Paciorek, Ann M; Hoffmann, K R; Bednarek, D R; Rudin, S

    2009-01-01

    Image-guided endovascular intervention (EIGI), using new flow modifying endovascular devices for intracranial aneurysm treatment is an active area of stroke research. The new polyurethane-asymmetric vascular stent (P-AVS), a vascular stent partially covered with a polyurethane-based patch, is used to cover the aneurysm neck, thus occluding flow into the aneurysm. This study involves angiographic imaging of partially covered aneurysm orifices. This particular situation could occur when the vascular geometry does not allow full aneurysm coverage. Four standard in-vivo rabbit-model aneurysms were investigated; two had stent patches placed over the distal region of the aneurysm orifice while the other two had stent patches placed over the proximal region of the aneurysm orifice. Angiographic analysis was used to evaluate aneurysm blood flow before and immediately after stenting and at four-week follow-up. The treatment results were also evaluated using histology on the aneurysm dome and electron microscopy on the aneurysm neck. Post-stenting angiographic flow analysis revealed aneurysmal flow reduction in all cases with faster flow in the distally-covered case and very slow flow and prolonged pooling for proximal-coverage. At follow-up, proximally-covered aneurysms showed full dome occlusion. The electron microscopy showed a remnant neck in both distally-placed stent cases but complete coverage in the proximally-placed stent cases. Thus, direct flow (impingement jet) removal from the aneurysm dome, as indicated by angiograms in the proximally-covered case, was sufficient to cause full aneurysm healing in four weeks; however, aneurysm healing was not complete for the distally-covered case. These results support further investigations into the treatment of aneurysms by flow-modification using partial aneurysm-orifice coverage.

  8. Computational aspects of algebraic curves

    CERN Document Server

    Shaska, Tanush

    2005-01-01

    The development of new computational techniques and better computing power has made it possible to attack some classical problems of algebraic geometry. The main goal of this book is to highlight such computational techniques related to algebraic curves. The area of research in algebraic curves is receiving more interest not only from the mathematics community, but also from engineers and computer scientists, because of the importance of algebraic curves in applications including cryptography, coding theory, error-correcting codes, digital imaging, computer vision, and many more.This book cove

  9. Radionuclide angiography in graded carotoid stenosis. An experimental study with angiographic correlation

    International Nuclear Information System (INIS)

    Weissman, B.N.; Holman, B.L.; Rosenbaum, A.E.

    1975-01-01

    Radionuclide and contrast angiographies were performed in 10 dogs. In 6 dogs unilateral or bilateral (partial or total) carotid occlusions were produced by silk ligatures. Follow-up angiographies were carried out at intervals up to 6 months following surgery. Visual assessment of the radionuclide carotid angiogram was compared to quantitative analysis of the time-activity curves over these areas. Several parameters of these curves were reviewed. The ratio of the slopes was the most sensitive parameter of the assessment of carotid artery stenosis. The ratio of the slopes of the curves in normal dogs (mean 96 +- 5.2 S.D.) was significantly different from that in animals with stenosis greater than 80 percent (mean 67.3 +- 16.9 S.D.). (U.S.)

  10. 51Cr - erythrocyte survival curves

    International Nuclear Information System (INIS)

    Paiva Costa, J. de.

    1982-07-01

    Sixteen patients were studied, being fifteen patients in hemolytic state, and a normal individual as a witness. The aim was to obtain better techniques for the analysis of the erythrocytes, survival curves, according to the recommendations of the International Committee of Hematology. It was used the radiochromatic method as a tracer. Previously a revisional study of the International Literature was made in its aspects inherent to the work in execution, rendering possible to establish comparisons and clarify phonomena observed in cur investigation. Several parameters were considered in this study, hindering both the exponential and the linear curves. The analysis of the survival curves of the erythrocytes in the studied group, revealed that the elution factor did not present a homogeneous answer quantitatively to all, though, the result of the analysis of these curves have been established, through listed programs in the electronic calculator. (Author) [pt

  11. Melting curves of gammairradiated DNA

    International Nuclear Information System (INIS)

    Hofer, H.; Altmann, H.; Kehrer, M.

    1978-08-01

    Melting curves of gammairradiated DNA and data derived of them, are reported. The diminished stability is explained by basedestruction. DNA denatures completely at room temperature, if at least every fifth basepair is broken or weakened by irradiation. (author)

  12. Management of the learning curve

    DEFF Research Database (Denmark)

    Pedersen, Peter-Christian; Slepniov, Dmitrij

    2016-01-01

    Purpose – This paper focuses on the management of the learning curve in overseas capacity expansions. The purpose of this paper is to unravel the direct as well as indirect influences on the learning curve and to advance the understanding of how these affect its management. Design...... the dimensions of the learning process involved in a capacity expansion project and identified the direct and indirect labour influences on the production learning curve. On this basis, the study proposes solutions to managing learning curves in overseas capacity expansions. Furthermore, the paper concludes...... with measures that have the potential to significantly reduce the non-value-added time when establishing new capacities overseas. Originality/value – The paper uses a longitudinal in-depth case study of a Danish wind turbine manufacturer and goes beyond a simplistic treatment of the lead time and learning...

  13. Growth curves for Laron syndrome.

    OpenAIRE

    Laron, Z; Lilos, P; Klinger, B

    1993-01-01

    Growth curves for children with Laron syndrome were constructed on the basis of repeated measurements made throughout infancy, childhood, and puberty in 24 (10 boys, 14 girls) of the 41 patients with this syndrome investigated in our clinic. Growth retardation was already noted at birth, the birth length ranging from 42 to 46 cm in the 12/20 available measurements. The postnatal growth curves deviated sharply from the normal from infancy on. Both sexes showed no clear pubertal spurt. Girls co...

  14. Flow over riblet curved surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, J B R; Freire, A P Silva, E-mail: atila@mecanica.ufrj.br [Mechanical Engineering Program, Federal University of Rio de Janeiro (COPPE/UFRJ), C.P. 68503, 21.941-972, Rio de Janeiro, RJ (Brazil)

    2011-12-22

    The present work studies the mechanics of turbulent drag reduction over curved surfaces by riblets. The effects of surface modification on flow separation over steep and smooth curved surfaces are investigated. Four types of two-dimensional surfaces are studied based on the morphometric parameters that describe the body of a blue whale. Local measurements of mean velocity and turbulence profiles are obtained through laser Doppler anemometry (LDA) and particle image velocimetry (PIV).

  15. Clinical usefulness of red cell distribution width to angiographic severity and coronary stent thrombosis

    Directory of Open Access Journals (Sweden)

    Erdem A

    2016-09-01

    high syntax score group had significantly higher RDW level (13.6 than the low syntax score group (12.9 (P=0.009. A positive correlation was determined between RDW and syntax scores (r=0.204.Conclusion: RDW is a new marker of poor prognosis in coronary artery disease. Increased RDW level is correlated with angiographic severity of coronary artery disease, and RDW may be an important clinical marker of coronary stent thrombosis in patients undergoing coronary intervention.Keywords: syntax score, stent thrombosis, red cell distribution width, coronary artery disease

  16. Optimization of three-dimensional angiographic data obtained by self-calibration of multiview imaging

    International Nuclear Information System (INIS)

    Noeel, Peter B.; Hoffmann, Kenneth R.; Kasodekar, Snehal; Walczak, Alan M.; Schafer, Sebastian

    2006-01-01

    Stroke is one of the leading causes of death in the U.S. The treatment of stroke often involves vascular interventions in which devices are guided to the intervention site often through tortuous vessels based on two-dimensional (2-D) angiographic images. Three dimensional (3-D) vascular information may facilitate these procedures. Methods have been proposed for the self-calibrating determination of 3-D vessel trees from biplane and multiple plane images and the geometric relationships between the views (imaging geometries). For the biplane analysis, four or more corresponding points must be identified in the biplane images. For the multiple view technique, multiple vessels must be indicated and only the translation vectors relating the geometries are calculated. We have developed methods for the calculation of the 3-D vessel data and the full transformations relating the multiple views (rotations and translations) obtained during interventional procedures, and the technique does not require indication of corresponding points, but only the indication of a single vessel, e.g., the vessel of interest. Multiple projection views of vessel trees are obtained and transferred to the analysis computer. The vessel or vessels of interest are indicated by the user. Using the initial imaging geometry determined from the gantry information, 3-D vessel centerlines are calculated using the indicated centerlines in pairs of images. The imaging geometries are then iteratively adjusted and 3-D centerlines recalculated until the root-mean-square (rms) difference between the calculated 3-D centerlines is minimized. Simulations indicate that the 3-D centerlines can be accurately determined (to within 1 mm) even for errors in indication of the vessel endpoints as large as 5 mm. In phantom studies, the average rms difference between the pairwise calculated 3-D centerlines is approximately 7.5 mm prior to refinement (i.e., using the gantry information alone), whereas the average rms

  17. Myocardial infarction in young versus older adults: clinical characteristics and angiographic features

    International Nuclear Information System (INIS)

    Shah, S.S.; Noor, L.; Shahsawar; Din, S.U.; Awan, Z.A.; Hafizullah, M.

    2010-01-01

    Background: Coronary artery disease is now frequently encountered in young adult population. However, being a relatively uncommon entity, not many studies are available in this regard. Therefore, the present study was designed to evaluate the clinical characteristics and angiographic features of patients less than 40 years of age with a history of myocardial infarction and compare them to patients older than 40 years. Methods: A total of 281 patients who underwent coronary angiography from April, 2009 to December, 2009, were included in this study. The patients were divided into two groups on the basis of age. Group A included patients 40 years of age or younger. Group B included patients older than 40 years. Both the groups were compared with respect to gender, hypertension, diabetes mellitus and extent and severity of coronary artery disease as assessed on coronary angiography. Results: Of the total 281 patients, 45 (16%) were less than or equal to 40 years old (Group-A) and 236 (84%) were older than 40 years (Group-B). There was no significant difference between the two groups with respect to the risk factors like gender, hypertension and diabetes mellitus. On coronary angiography, the two groups neither differed in the number of totally occluded vessels, nor in the severity of the culprit lesion. There were only 3 patients in group-A (6.7%) and 5 patients in group-B (2.1%) with normal coronaries (p=NS). Majority (60%) of the patients in group-A had no significant disease or single vessel disease while majority (69%) of the patients in group-B had two or more vessels involved (p<0.001). As far as the number of lesions in the coronary arteries is concerned, 62.3% patients had 2 or lesser lesions in group-A while 68.6% patients in group-B had three or more lesions (p=0.001). Conclusion: These data suggest that in our study, young patients with MI do not have significantly high prevalence of normal coronaries compared to older patients. Young patients are similar

  18. Comparison of the accuracy of three angiographic methods for calculating left ventricular volume measurement

    International Nuclear Information System (INIS)

    Hu Lin; Cui Wei; Shi Hanwen; Tian Yingping; Wang Weigang; Feng Yanguang; Huang Xueyan; Liu Zhisheng

    2003-01-01

    Objective: To compare the relative accuracy of three methods measuring left ventricular volume by X-ray ventriculography: single plane area-length method, biplane area-length method, and single-plane Simpson's method. Methods: Left ventricular casts were obtained within 24 hours after death from 12 persons who died from non-cardiac causes. The true left ventricular cast volume was measured by water displacement. The calculated volume of the casts was obtained with 3 angiographic methods, i.e., single-plane area-length method, biplane area-length method, and single-plane Simpson's method. Results: The actual average volume of left ventricular casts was (61.17±26.49) ml. The left ventricular volume was averagely (97.50±35.56) ml with single plane area-length method, (90.51±36.33) ml with biplane area-length method, and (65.00± 23.63) ml with single-plane Simpson's method. The left ventricular volumes calculated with single-plane and biplane area-length method were significantly larger than that the actual volumes (P 0.05). The left ventricular volumes calculated with single-plane and biplane area-length method were significantly larger than those calculated with single-plane Simpson's method (P 0.05). The over-estimation of left ventricular volume by single plane area-length method (36.34±17.98) ml and biplane area-length method (29.34±15.59) ml was more obvious than that calculated by single-plane Simpson's method (3.83±8.48) ml. Linear regression analysis showed that there was close correlations between left ventricular volumes calculated with single plane area-length method, biplane area-length method, Simpson's method and the true volume (all r>0.98). Conclusion: Single-plane Simpson's method is more accurate than single plane area-length method and biplane area-length method for left ventricular volume measurement; however, both the single-plane and biplane area-length methods could be used in clinical practice, especially in those imaging modality

  19. Intersection numbers of spectral curves

    CERN Document Server

    Eynard, B.

    2011-01-01

    We compute the symplectic invariants of an arbitrary spectral curve with only 1 branchpoint in terms of integrals of characteristic classes in the moduli space of curves. Our formula associates to any spectral curve, a characteristic class, which is determined by the laplace transform of the spectral curve. This is a hint to the key role of Laplace transform in mirror symmetry. When the spectral curve is y=\\sqrt{x}, the formula gives Kontsevich--Witten intersection numbers, when the spectral curve is chosen to be the Lambert function \\exp{x}=y\\exp{-y}, the formula gives the ELSV formula for Hurwitz numbers, and when one chooses the mirror of C^3 with framing f, i.e. \\exp{-x}=\\exp{-yf}(1-\\exp{-y}), the formula gives the Marino-Vafa formula, i.e. the generating function of Gromov-Witten invariants of C^3. In some sense this formula generalizes ELSV, Marino-Vafa formula, and Mumford formula.

  20. Dissolution glow curve in LLD

    International Nuclear Information System (INIS)

    Haverkamp, U.; Wiezorek, C.; Poetter, R.

    1990-01-01

    Lyoluminescence dosimetry is based upon light emission during dissolution of previously irradiated dosimetric materials. The lyoluminescence signal is expressed in the dissolution glow curve. These curves begin, depending on the dissolution system, with a high peak followed by an exponentially decreasing intensity. System parameters that influence the graph of the dissolution glow curve, are, for example, injection speed, temperature and pH value of the solution and the design of the dissolution cell. The initial peak does not significantly correlate with the absorbed dose, it is mainly an effect of the injection. The decay of the curve consists of two exponential components: one fast and one slow. The components depend on the absorbed dose and the dosimetric materials used. In particular, the slow component correlates with the absorbed dose. In contrast to the fast component the argument of the exponential function of the slow component is independent of the dosimetric materials investigated: trehalose, glucose and mannitol. The maximum value, following the peak of the curve, and the integral light output are a measure of the absorbed dose. The reason for the different light outputs of various dosimetric materials after irradiation with the same dose is the differing solubility. The character of the dissolution glow curves is the same following irradiation with photons, electrons or neutrons. (author)

  1. Curve Boxplot: Generalization of Boxplot for Ensembles of Curves.

    Science.gov (United States)

    Mirzargar, Mahsa; Whitaker, Ross T; Kirby, Robert M

    2014-12-01

    In simulation science, computational scientists often study the behavior of their simulations by repeated solutions with variations in parameters and/or boundary values or initial conditions. Through such simulation ensembles, one can try to understand or quantify the variability or uncertainty in a solution as a function of the various inputs or model assumptions. In response to a growing interest in simulation ensembles, the visualization community has developed a suite of methods for allowing users to observe and understand the properties of these ensembles in an efficient and effective manner. An important aspect of visualizing simulations is the analysis of derived features, often represented as points, surfaces, or curves. In this paper, we present a novel, nonparametric method for summarizing ensembles of 2D and 3D curves. We propose an extension of a method from descriptive statistics, data depth, to curves. We also demonstrate a set of rendering and visualization strategies for showing rank statistics of an ensemble of curves, which is a generalization of traditional whisker plots or boxplots to multidimensional curves. Results are presented for applications in neuroimaging, hurricane forecasting and fluid dynamics.

  2. Angiographic Embolization of a Postpartum Vulvovaginal Hematoma in a Patient with Situs Inversus Totalis: An Effective Second-Line Treatment

    Directory of Open Access Journals (Sweden)

    Elias M. Dahdouh

    2013-01-01

    Full Text Available Situs inversus totalis is a rare congenital anomaly where asymmetrical positioning of internal organs may affect the surgical and radiological management of certain conditions. Vulvovaginal hematoma is a life-threatening complication of vaginal delivery whose primary treatment usually consists of incision and drainage of the hematoma and ligation of the responsible vessels, followed by wound packing. Failure of these measures to control the bleeding was previously considered as an indication for laparotomy to perform bilateral hypogastric artery ligation and, if needed, a hysterectomy. Relative to major abdominal surgery, selective percutaneous angiographic embolization offers considerable advantages and significant less morbidity. Indeed, angiographic embolization is routinely used as a measure to control refractory pelvic bleeding, though the literature and experience in women with situs inversus totalis are scarce. In this paper, we report a case of postpartum vulvovaginal hematoma in a patient with situs inversus, refractory to conventional treatment, where arteriographic embolization was successfully used to control the bleeding. The management of this obstetrical complication and the use of this minimally invasive technique are also reviewed. To the best of our knowledge, this is the first report in the literature describing the feasibility of this technique in a patient with situs inversus totalis.

  3. Angiographically borderline left main coronary artery lesions: correlation of transthoracic doppler echocardiography and intravascular ultrasound: a pilot study

    Directory of Open Access Journals (Sweden)

    Varga Albert

    2011-06-01

    Full Text Available Abstract Background the clinical decision making could be difficult in patients with borderline lesions (visually assessed stenosis severity of 30 to 50% of the left main coronary artery (LM. The aim of the study was to evaluate the relationship between transthoracic Doppler (TTDE peak diastolic flow velocity (PDV and intravascular ultrasound (IVUS measurements in the assessment of angiographically borderline LM lesions. Methods 27 patients (mean age 64 ± 8 years, 21 males with borderline LM stenosis referred for IVUS examination were included in the study. We performed standard IVUS with minimal lumen area (MLA and plaque burden (PB measurement and routine quantitative coronary angiography (QCA with diameter stenosis (%DS and area stenosis (%AS assessment in all. During TTDE, resting PDV was measured in the LM. Results interpretable Doppler signal could be obtained in 24 patients (88% feasibility; therefore these patients entered the final analysis. MLA was 7.1 ± 2.7 mm2. TTDE measured PDV correlated significantly with IVUS-derived MLA (r = -0.46, p 2 LM stenosis. Conclusion In angiographically borderline LM disease, resting PDV from transthoracic echocardiography is increased in presence of increased plaque burden by IVUS. TTDE evaluation might be a useful adjunct to other invasive and non-invasive methods in the assessment of borderline LM lesions. Further, large scale studies are needed to establish the exact cut-off value of PDV for routine clinical application.

  4. Brachytherapy using holmium-166 liquid balloon system for in-stent restenosis: 6 months clinical and angiographic follow-up

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M. H.; Kim, S. K.; Cha, K. S.; Kim, Y. D.; Lee, H. S.; Kang, D. Y. [Donga University College of Medicine, Busan (Korea, Republic of)

    2002-07-01

    In western country, 3 systems of brachytherapy using commercial radioactive source has been established. However, brachytherapy using holmium-166 liquid balloon system (HLBS) for the patient with stent restenosis has not been studied enough. 30 patients (male 23, mean age 58.9 7.7) were enrolled. Target dose was 15 Gy at 1 mm distance from the intimal surface. Clinical diagnoses of the study patients included stable angina 10 and unstable angina 20 patients. Target lesion included LAD 19, LCx 5 and RCA 6 arteries. Pre-brachytherapy treatment included cutting balloon angioplasty in 25, rotational atherectomy in 5 patients. Fractionation and stepping was done in 6 patients each. Follow-up angiography was done in 19 patients. Of them, 4 cases developed angiographic restenosis (21%) including 3 cases of total occlusion. 6 month MACE (major adverse cardiac event) occurred in 5 patients including one sudden cardiac death in a patient with 80 year-old, triple-vessel diseased patient. Vascular brachytherapy using HLBS is a safe and effective treatment modality for in-stent restenosis showing acceptable angiographic and clinical result.

  5. Agreement between clinical estimation and a new quantitative analysis by Photoshop software in fundus and angiographic image variables.

    Science.gov (United States)

    Ramezani, Alireza; Ahmadieh, Hamid; Azarmina, Mohsen; Soheilian, Masoud; Dehghan, Mohammad H; Mohebbi, Mohammad R

    2009-12-01

    To evaluate the validity of a new method for the quantitative analysis of fundus or angiographic images using Photoshop 7.0 (Adobe, USA) software by comparing with clinical evaluation. Four hundred and eighteen fundus and angiographic images of diabetic patients were evaluated by three retina specialists and then by computing using Photoshop 7.0 software. Four variables were selected for comparison: amount of hard exudates (HE) on color pictures, amount of HE on red-free pictures, severity of leakage, and the size of the foveal avascular zone (FAZ). The coefficient of agreement (Kappa) between the two methods in the amount of HE on color and red-free photographs were 85% (0.69) and 79% (0.59), respectively. The agreement for severity of leakage was 72% (0.46). In the two methods for the evaluation of the FAZ size using the magic and lasso software tools, the agreement was 54% (0.09) and 89% (0.77), respectively. Agreement in the estimation of the FAZ size by the lasso magnetic tool was excellent and was almost as good in the quantification of HE on color and on red-free images. Considering the agreement of this new technique for the measurement of variables in fundus images using Photoshop software with the clinical evaluation, this method seems to have sufficient validity to be used for the quantitative analysis of HE, leakage, and FAZ size on the angiograms of diabetic patients.

  6. Quantitative assessment of angiogenesis in the chick embryo and its chorioallantoic membrane by computerised analysis of angiographic images

    International Nuclear Information System (INIS)

    Nikiforidis, G.; Papazafiropoulos, D.; Siablis, D.; Karnabatidis, D.; Hatjikondi, O.; Dimopoulos, J.

    1999-01-01

    We studied, in vivo, the angiogenesis process in the chick embryo and its chorioallantoic membrane (CAM) using digital subtraction angiography (DSA) in conjunction with computer-assisted image analysis. In a series of fertilised eggs, angiography was carried out at days 8, 10, 12 and 14 of embryonic development. The angiographic images were digitised and subsequently processed for a specific image analysis. A set of specific morphological parameters has been defined to allow an analytical characterisation of the vascularity status. Vessels were classified into three categories according to their diameter (50-100, 100-200, and >200 μm). The data were normalised and statistically evaluated. Graphs showing the development of angiogenesis were obtained. Total vascular area revealed a continuous rise, whereas, total vascular length increased until day 12 and then it started decreasing. These morphometric parameters in the first two vessel categories progressively increased throughout the entire period of development, whereas in the third category they increased until day 10 and then they started decreasing. By applying a vascular casting technique CAM vessels were visualised and compared with those extracted from the processed angiographic image. The comparison revealed that there is exact matching for the first two vessel categories (diameters higher than 100 μm) while the matching of the third category (diameters between 50 and 100 μm) is approximate

  7. Considerations for reference pump curves

    International Nuclear Information System (INIS)

    Stockton, N.B.

    1992-01-01

    This paper examines problems associated with inservice testing (IST) of pumps to assess their hydraulic performance using reference pump curves to establish acceptance criteria. Safety-related pumps at nuclear power plants are tested under the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (the Code), Section 11. The Code requires testing pumps at specific reference points of differential pressure or flow rate that can be readily duplicated during subsequent tests. There are many cases where test conditions cannot be duplicated. For some pumps, such as service water or component cooling pumps, the flow rate at any time depends on plant conditions and the arrangement of multiple independent and constantly changing loads. System conditions cannot be controlled to duplicate a specific reference value. In these cases, utilities frequently request to use pump curves for comparison of test data for acceptance. There is no prescribed method for developing a pump reference curve. The methods vary and may yield substantially different results. Some results are conservative when compared to the Code requirements; some are not. The errors associated with different curve testing techniques should be understood and controlled within reasonable bounds. Manufacturer's pump curves, in general, are not sufficiently accurate to use as reference pump curves for IST. Testing using reference curves generated with polynomial least squares fits over limited ranges of pump operation, cubic spline interpolation, or cubic spline least squares fits can provide a measure of pump hydraulic performance that is at least as accurate as the Code required method. Regardless of the test method, error can be reduced by using more accurate instruments, by correcting for systematic errors, by increasing the number of data points, and by taking repetitive measurements at each data point

  8. Curve Digitizer – A software for multiple curves digitizing

    Directory of Open Access Journals (Sweden)

    Florentin ŞPERLEA

    2010-06-01

    Full Text Available The Curve Digitizer is software that extracts data from an image file representing a graphicand returns them as pairs of numbers which can then be used for further analysis and applications.Numbers can be read on a computer screen stored in files or copied on paper. The final result is adata set that can be used with other tools such as MSEXCEL. Curve Digitizer provides a useful toolfor any researcher or engineer interested in quantifying the data displayed graphically. The image filecan be obtained by scanning a document

  9. Calibration curves for biological dosimetry

    International Nuclear Information System (INIS)

    Guerrero C, C.; Brena V, M. . E-mail cgc@nuclear.inin.mx

    2004-01-01

    The generated information by the investigations in different laboratories of the world, included the ININ, in which settles down that certain class of chromosomal leisure it increases in function of the dose and radiation type, has given by result the obtaining of calibrated curves that are applied in the well-known technique as biological dosimetry. In this work is presented a summary of the work made in the laboratory that includes the calibrated curves for gamma radiation of 60 Cobalt and X rays of 250 k Vp, examples of presumed exposure to ionizing radiation, resolved by means of aberration analysis and the corresponding dose estimate through the equations of the respective curves and finally a comparison among the dose calculations in those people affected by the accident of Ciudad Juarez, carried out by the group of Oak Ridge, USA and those obtained in this laboratory. (Author)

  10. Vertex algebras and algebraic curves

    CERN Document Server

    Frenkel, Edward

    2004-01-01

    Vertex algebras are algebraic objects that encapsulate the concept of operator product expansion from two-dimensional conformal field theory. Vertex algebras are fast becoming ubiquitous in many areas of modern mathematics, with applications to representation theory, algebraic geometry, the theory of finite groups, modular functions, topology, integrable systems, and combinatorics. This book is an introduction to the theory of vertex algebras with a particular emphasis on the relationship with the geometry of algebraic curves. The notion of a vertex algebra is introduced in a coordinate-independent way, so that vertex operators become well defined on arbitrary smooth algebraic curves, possibly equipped with additional data, such as a vector bundle. Vertex algebras then appear as the algebraic objects encoding the geometric structure of various moduli spaces associated with algebraic curves. Therefore they may be used to give a geometric interpretation of various questions of representation theory. The book co...

  11. Curve collection, extension of databases

    International Nuclear Information System (INIS)

    Gillemot, F.

    1992-01-01

    Full text: Databases: generally calculated data only. The original measurements: diagrams. Information loss between them Expensive research eg. irradiation, aging, creep etc. Original curves should be stored for reanalysing. The format of the stored curves: a. Data in ASCII files, only numbers b. Other information in strings in a second file Same name, but different extension. Extensions shows the type of the test and the type of the file. EXAMPLES. TEN is tensile information, TED is tensile data, CHN is Charpy informations, CHD is Charpy data. Storing techniques: digitalised measurements, digitalising old curves stored on paper. Use: making catalogues, reanalysing, comparison with new data. Tools: mathematical software packages like quattro, genplot, exel, mathcad, qbasic, pascal, fortran, mathlab, grapher etc. (author)

  12. Rational points on elliptic curves

    CERN Document Server

    Silverman, Joseph H

    2015-01-01

    The theory of elliptic curves involves a pleasing blend of algebra, geometry, analysis, and number theory. This book stresses this interplay as it develops the basic theory, thereby providing an opportunity for advanced undergraduates to appreciate the unity of modern mathematics. At the same time, every effort has been made to use only methods and results commonly included in the undergraduate curriculum. This accessibility, the informal writing style, and a wealth of exercises make Rational Points on Elliptic Curves an ideal introduction for students at all levels who are interested in learning about Diophantine equations and arithmetic geometry. Most concretely, an elliptic curve is the set of zeroes of a cubic polynomial in two variables. If the polynomial has rational coefficients, then one can ask for a description of those zeroes whose coordinates are either integers or rational numbers. It is this number theoretic question that is the main subject of this book. Topics covered include the geometry and ...

  13. Theoretical melting curve of caesium

    International Nuclear Information System (INIS)

    Simozar, S.; Girifalco, L.A.; Pennsylvania Univ., Philadelphia

    1983-01-01

    A statistical-mechanical model is developed to account for the complex melting curve of caesium. The model assumes the existence of three different species of caesium defined by three different electronic states. On the basis of this model, the free energy of melting and the melting curve are computed up to 60 kbar, using the solid-state data and the initial slope of the fusion curve as input parameters. The calculated phase diagram agrees with experiment to within the experimental error. Other thermodynamic properties including the entropy and volume of melting were also computed, and they agree with experiment. Since the theory requires only one adjustable constant, this is taken as strong evidence that the three-species model is satisfactory for caesium. (author)

  14. Migration and the Wage Curve:

    DEFF Research Database (Denmark)

    Brücker, Herbert; Jahn, Elke J.

    in a general equilibrium framework. For the empirical analysis we employ the IABS, a two percent sample of the German labor force. We find that the elasticity of the wage curve is particularly high for young workers and workers with a university degree, while it is low for older workers and workers......  Based on a wage curve approach we examine the labor market effects of migration in Germany. The wage curve relies on the assumption that wages respond to a change in the unemployment rate, albeit imperfectly. This allows one to derive the wage and employment effects of migration simultaneously...... with a vocational degree. The wage and employment effects of migration are moderate: a 1 percent increase in the German labor force through immigration increases the aggregate unemployment rate by less than 0.1 percentage points and reduces average wages by less 0.1 percent. While native workers benefit from...

  15. Laffer Curves and Home Production

    Directory of Open Access Journals (Sweden)

    Kotamäki Mauri

    2017-06-01

    Full Text Available In the earlier related literature, consumption tax rate Laffer curve is found to be strictly increasing (see Trabandt and Uhlig (2011. In this paper, a general equilibrium macro model is augmented by introducing a substitute for private consumption in the form of home production. The introduction of home production brings about an additional margin of adjustment – an increase in consumption tax rate not only decreases labor supply and reduces the consumption tax base but also allows a substitution of market goods with home-produced goods. The main objective of this paper is to show that, after the introduction of home production, the consumption tax Laffer curve exhibits an inverse U-shape. Also the income tax Laffer curves are significantly altered. The result shown in this paper casts doubt on some of the earlier results in the literature.

  16. Complexity of Curved Glass Structures

    Science.gov (United States)

    Kosić, T.; Svetel, I.; Cekić, Z.

    2017-11-01

    Despite the increasing number of research on the architectural structures of curvilinear forms and technological and practical improvement of the glass production observed over recent years, there is still a lack of comprehensive codes and standards, recommendations and experience data linked to real-life curved glass structures applications regarding design, manufacture, use, performance and economy. However, more and more complex buildings and structures with the large areas of glass envelope geometrically complex shape are built every year. The aim of the presented research is to collect data on the existing design philosophy on curved glass structure cases. The investigation includes a survey about how architects and engineers deal with different design aspects of curved glass structures with a special focus on the design and construction process, glass types and structural and fixing systems. The current paper gives a brief overview of the survey findings.

  17. Optimising cardiac/angiographic digital images using a Butternut as the image quality phantom

    International Nuclear Information System (INIS)

    Bibbo, G.; Balman, D.

    2008-01-01

    Full text: Digital images, whether produced by image intensifiers, flat panels or computed radiography imaging plates, have a broad dynamic range and, thus, there is a need to adjust the exposure parameters of the imaging protocols to obtain diagnostic images without over exposing patients. The default exposure techniques of protocols delivered with the imaging equipment are in general set to produce high quality images at the expense of high radiation doses to patients. Ideally, these protocols should be optimised for best possible image quality at the lowest possible patient dose, particularly for paediatric patients. Manufacturers of equipment do not generally supply paediatric protocols and, thus, the default settings of the adult protocols have to be adjusted for paediatric patients. Optimising imaging protocols is not a trivial matter and, without a suitable phantom, it is difficult and time consuming. Commercial phantoms are commonly used to optimise adult protocols, but these are made of dry materials such as perspex, Teflon, aluminium, dry bone as in dry skulls, or a combination of these materials. The problem with these phantoms is that the features on their images are artificial, not simulating any characteristics of patients' anatomic details. In optimising paediatric protocols for our new cardiac/angiographic Siemens Biplane Digital Imaging System, we searched for a paediatric phantom with moisture content, and found that the humble butternut pumpkin (cucurbita moschate) from the squash family makes a good paediatric phantom, particularly, when it is injected with contrast. The part of the butternut that is useful as a phantom is the pulp, i.e., the part that contains the seeds. This is also the part where the contrast is injected. The image of the pulp contains structures that are natural as the butternut is the fruit of a living plant. The image of the seeds is suitable for low-level contrast detectability while fine structures enhanced by the

  18. Optimization on Spaces of Curves

    DEFF Research Database (Denmark)

    Møller-Andersen, Jakob

    in Rd, and methods to solve the initial and boundary value problem for geodesics allowing us to compute the Karcher mean and principal components analysis of data of curves. We apply the methods to study shape variation in synthetic data in the Kimia shape database, in HeLa cell nuclei and cycles...... of cardiac deformations. Finally we investigate a new application of Riemannian shape analysis in shape optimization. We setup a simple elliptic model problem, and describe how to apply shape calculus to obtain directional derivatives in the manifold of planar curves. We present an implementation based...

  19. Tracing a planar algebraic curve

    International Nuclear Information System (INIS)

    Chen Falai; Kozak, J.

    1994-09-01

    In this paper, an algorithm that determines a real algebraic curve is outlined. Its basic step is to divide the plane into subdomains that include only simple branches of the algebraic curve without singular points. Each of the branches is then stably and efficiently traced in the particular subdomain. Except for the tracing, the algorithm requires only a couple of simple operations on polynomials that can be carried out exactly if the coefficients are rational, and the determination of zeros of several polynomials of one variable. (author). 5 refs, 4 figs

  20. The New Keynesian Phillips Curve

    DEFF Research Database (Denmark)

    Ólafsson, Tjörvi

    This paper provides a survey on the recent literature on the new Keynesian Phillips curve: the controversies surrounding its microfoundation and estimation, the approaches that have been tried to improve its empirical fit and the challenges it faces adapting to the open-economy framework. The new......, learning or state-dependant pricing. The introduction of openeconomy factors into the new Keynesian Phillips curve complicate matters further as it must capture the nexus between price setting, inflation and the exchange rate. This is nevertheless a crucial feature for any model to be used for inflation...... forecasting in a small open economy like Iceland....

  1. Signature Curves Statistics of DNA Supercoils

    OpenAIRE

    Shakiban, Cheri; Lloyd, Peter

    2004-01-01

    In this paper we describe the Euclidean signature curves for two dimensional closed curves in the plane and their generalization to closed space curves. The focus will be on discrete numerical methods for approximating such curves. Further we will apply these numerical methods to plot the signature curves related to three-dimensional simulated DNA supercoils. Our primary focus will be on statistical analysis of the data generated for the signature curves of the supercoils. We will try to esta...

  2. The relationship between cerebral infarction on MR and angiographic findings in moyamoya disease: significance of the posterior circulation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Ja; Song, Soon Young [College of Medicine, Kwangdong Univ., Koyang (Korea, Republic of); Yu, Won Jong; Jung, So Lyung; Chung, Bong Gak; Kag, Si Won [College of Medicine, The Catholic Univ. of Korea, Seoul (Korea, Republic of); Kim, Man Deuk [College of Medicine, Pochon CHA Univ., Pochon (Korea, Republic of)

    2002-06-01

    To investigate the relationship between changes in the posterior and anterior circulation, as seen at angiography, and the frequency and extent of cerebral infarction revealed by MR imaging in moyamoya disease. This study involved 34 patients (22 females and 12 males, aged 2-52 years) in whom cerebral angiography revealed the presence of moyamoya disease (bilateral; unilateral= 24:10; total hemispheres=58) and who also underwent brain MR imaging. To evaluate the angiographic findings, we applied each angiographic staging system to the anterior and posterior circulation. Leptomeningeal collateral circulation from the cortical branches of the posterior cerebral artery (PCA) was also assigned one of four grades. At MR imaging, areas of cerebral cortical or subcortical infarction in the hemisphere were divided into six zones. White matter and basal ganglionic infarction, ventricular dilatation, cortical atrophy, and hemorrhagic lesions were also evaluated. To demonstrate the statistical significance of the relationship between the angiographic and the MR findings, both the Mantel-Haenszel chi-square test for trend and the chi-square test were used. The degree of steno-occlusive PCA change correlated significantly with the internal carotid artery (ICA) stage (p<0.0001). As PCA stages advanced, the degree of leptomeningeal collaterals from the PCA decreased significantly (P<0.0001), but ICA stages were not significant (p>0.05). The prevalence of infarction showed significant correlation with the degree of steno-occlusive change in both the ICA and PCA. The degree of cerebral ischemia in moyamoya patients increased proportionally with the severity of PCA stenosis rather than with that of steno-occlusive lesins of the anterior circulation. Infarctions tended to be distributed in the anterior part of the hemisphere at PCA state I or II, while in more advanced PCA lesions, they were also found posteriorly, especially in the territories of the posterior middle cerebral artery

  3. MR imaging findings of high-voltage electrical burns in the upper extremities: correlation with angiographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Gyung Kyu; Kang, Ik Won; Hwang, Dae Hyun; Min, Seon Jung; Han, You Mi (Dept. of Radiology, Hallym Univ. College of Medicine, Hangang Sacred Heart Hospital, Seoul (Korea, Republic of)); Suh, Kyung Jin (Dept. of Radiology, Dongguk Univ. College of Medicine, Gyeongju Hospital, Gyeongju (Korea, Republic of)), email: kyungjin.suh@gmail.com; Choi, Min Ho (Dept. of Internal Medicine, Hallym Univ. College of Medicine, Hangang Sacred Heart Hospital, Seoul (Korea, Republic of))

    2011-02-15

    Background: A high-voltage electrical burn is often associated with deep muscle injuries. Hidden, undetected deep muscle injuries have a tendency for progressive tissue necrosis, and this can lead to major amputations or sepsis. MRI has excellent soft tissue contrast and it may aid in differentiating the areas of viable deep muscle from the areas of non-viable deep muscle. Purpose: To describe the MR imaging findings of a high-voltage electrical burn in the upper extremity with emphasis on the usefulness of the gadolinium-enhanced MRI and to compare the MR imaging findings with angiography. Material and Methods: We retrospectively reviewed the imaging studies of six patients with high-voltage electrical burns who underwent both MRI and angiography at the burn center of our hospital from January 2005 to December 2009. The imaging features were evaluated for the involved locations, the MR signal intensity of the affected muscles, the MR enhancement pattern, the involved arteries and the angiographic findings (classified as normal, sluggish flow, stenosis or occlusion) of the angiography of the upper extremity. We assessed the relationship between the MR imaging findings and the angiographic findings. Results: The signal intensities of affected muscles were isointense or of slightly high signal intensity as compared with the adjacent unaffected skeletal muscle on the T1-weighted MR images. Affected muscles showed heterogenous high signal intensity relative to the adjacent unaffected skeletal muscle on the T2- weighted images. The gadolinium-enhanced T1-weighted images showed diffuse inhomogeneous enhancement or peripheral rim enhancement of the affected muscles. The angiographic findings of the arterial injuries showed complete occlusion in three patients, severe stenosis in two patients and sluggish flow in one patient. Of these, the five patients with complete occlusion or severe stenosis on angiography showed non-perfused and non-viable areas of edematous muscle on

  4. Dual Smarandache Curves of a Timelike Curve lying on Unit dual Lorentzian Sphere

    OpenAIRE

    Kahraman, Tanju; Hüseyin Ugurlu, Hasan

    2016-01-01

    In this paper, we give Darboux approximation for dual Smarandache curves of time like curve on unit dual Lorentzian sphere. Firstly, we define the four types of dual Smarandache curves of a timelike curve lying on dual Lorentzian sphere.

  5. Electro-Mechanical Resonance Curves

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2018-01-01

    Recently I have been investigating the frequency response of galvanometers. These are direct-current devices used to measure small currents. By using a low-frequency function generator to supply the alternating-current signal and a stopwatch smartphone app to measure the period, I was able to take data to allow a resonance curve to be drawn. This…

  6. Texas curve margin of safety.

    Science.gov (United States)

    2013-01-01

    This software can be used to assist with the assessment of margin of safety for a horizontal curve. It is intended for use by engineers and technicians responsible for safety analysis or management of rural highway pavement or traffic control devices...

  7. Principal Curves on Riemannian Manifolds.

    Science.gov (United States)

    Hauberg, Soren

    2016-09-01

    Euclidean statistics are often generalized to Riemannian manifolds by replacing straight-line interpolations with geodesic ones. While these Riemannian models are familiar-looking, they are restricted by the inflexibility of geodesics, and they rely on constructions which are optimal only in Euclidean domains. We consider extensions of Principal Component Analysis (PCA) to Riemannian manifolds. Classic Riemannian approaches seek a geodesic curve passing through the mean that optimizes a criteria of interest. The requirements that the solution both is geodesic and must pass through the mean tend to imply that the methods only work well when the manifold is mostly flat within the support of the generating distribution. We argue that instead of generalizing linear Euclidean models, it is more fruitful to generalize non-linear Euclidean models. Specifically, we extend the classic Principal Curves from Hastie & Stuetzle to data residing on a complete Riemannian manifold. We show that for elliptical distributions in the tangent of spaces of constant curvature, the standard principal geodesic is a principal curve. The proposed model is simple to compute and avoids many of the pitfalls of traditional geodesic approaches. We empirically demonstrate the effectiveness of the Riemannian principal curves on several manifolds and datasets.

  8. Elliptic curves and primality proving

    Science.gov (United States)

    Atkin, A. O. L.; Morain, F.

    1993-07-01

    The aim of this paper is to describe the theory and implementation of the Elliptic Curve Primality Proving algorithm. Problema, numeros primos a compositis dignoscendi, hosque in factores suos primos resolvendi, ad gravissima ac utilissima totius arithmeticae pertinere, et geometrarum tum veterum tum recentiorum industriam ac sagacitatem occupavisse, tam notum est, ut de hac re copiose loqui superfluum foret.

  9. A Curve for all Reasons

    Indian Academy of Sciences (India)

    from biology, feel that every pattern in the living world, ranging from the folding of ... curves band c have the same rate of increase but reach different asymptotes. If these .... not at x = 0, but at xo' which is the minimum size at birth that will permit ...

  10. Survival curves for irradiated cells

    International Nuclear Information System (INIS)

    Gibson, D.K.

    1975-01-01

    The subject of the lecture is the probability of survival of biological cells which have been subjected to ionising radiation. The basic mathematical theories of cell survival as a function of radiation dose are developed. A brief comparison with observed survival curves is made. (author)

  11. Optimal use of directional coronary atherectomy is required to ensure long-term angiographic benefit: a study with matched procedural outcome after atherectomy and angioplasty

    NARCIS (Netherlands)

    V.A.W.M. Umans (Victor); D.T.J. Keane (David); R. Melkert (Rein); P.W.J.C. Serruys (Patrick); D.P. Foley (David); H. Boersma (Eric)

    1994-01-01

    textabstractOBJECTIVES. This study was designed to examine whether restenosis is related to the extent or mechanism of lumen improvement and to explore angiographic determinants of optimal atherectomy. BACKGROUND. Directional atherectomy induces a greater extent of immediate gain and late loss but

  12. A new self-expanding nitinol stent (Enterprise) for the treatment of wide-necked intracranial aneurysms: initial clinical and angiographic results in 31 aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Werner; Kuehne, Dietmar [Alfried Krupp Hospital, Department of Radiology and Neuroradiology, Essen (Germany); Bendszus, Martin; Solymosi, Laszlo [University of Wuerzburg, Department of Neuroradiology, Wuerzburg (Germany); Kis, Bernhard [University of Duisburg-Essen, Research Unit, Rheinische Kliniken Essen, Department of Psychiatry and Psychotherapy, Essen (Germany); Boulanger, Thierry [Centre Hospitalier of Luxembourg, Service of Neuroradiology, Luxembourg (Luxembourg)

    2007-07-15

    We report the results of a prospective clinical study using a new self-expanding nitinol stent (Enterprise) designed for the treatment of wide-necked intracranial aneurysms. We treated 31 saccular, wide-necked intracranial aneurysms in 30 patients. Ten aneurysms had recanalized after prior endovascular treatment without a stent, and 21 aneurysms had not been treated before. Stent deployment was successful in all procedures. Additional coil embolization was performed in all aneurysms. Initial complete angiographic occlusion was achieved in 6 aneurysms, a neck remnant was left in 18 aneurysms and there were 7 residual aneurysms. Angiographic follow-up examinations of 30 lesions after 6 months demonstrated 15 complete occlusions, 8 neck remnants and 7 residual aneurysms. One patient refused the 6-month angiographic follow-up. Spontaneous occlusion of the aneurysm had occurred in 14 patients, and 6 aneurysms showed recanalization. Four of these residual aneurysms were retreated. At the 6-month follow-up, 29 parent arteries were unaffected, whereas two parent vessels demonstrated minor asymptomatic narrowing at the stent site. Two patients experienced one or more possible or probable device-related serious adverse events during the 6-month follow-up period. There was no procedural morbidity or mortality at 6 months after the procedure. The reported results demonstrated the safety and feasibility of the Cordis Neurovascular Enterprise stent in the treatment of wide-necked intracranial aneurysms. Initial clinical and angiographic results are favorable. (orig.)

  13. Economic evaluation of angiographic interventions including a whole-radiology in- and outpatient care; Wirtschaftliche Evaluation angiographischer Interventionen einschliesslich einer radiologischen stationaeren und ambulanten Patientenbetreuung

    Energy Technology Data Exchange (ETDEWEB)

    Nolte-Ernsting, C.; Abel, K.; Krupski, G.; Lorenzen, J.; Adam, G. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany)

    2006-01-01

    Purpose: To determine the economic efficiency of a whole-radiology in- and outpatient treatment with angiographic interventions performed as the main or sole therapy. Materials and Methods: The calculations represent the data of a university radiology department, including the following angiographic interventions (neuroradiology not considered): Vascular intervention (PTA, stent implantation) of kidneys and extremities, recanalization of hemodialysis access, chemoembolization, diagnostic arterioportal liver CT, port implantation, varicocele embolization, PTCD, percutaneous implantation of biliary stent. First, the different angiographic interventions are categorized with reference to the German DRG system 2005. Considering the example of a university hospital, the individual cost of each intervention is calculated and correlated with reimbursements by G-DRG2005 and so-called ''ambulant operation'' (EBM200plus). With these data, profits and losses are calculated for both in- and outpatient care. Results: Radiologic interventions of inpatients yield a profit in the majority of cases. With a base rate of 2900 Euro, the profits in our university hospital range between -872 Euro and +3411 Euro (mean: +1348 Euro). On the other hand, those angiographic interventions suitable for ''ambulant operation'' generate average profits of +372 Euro, if only direct costs are considered. The data of outpatient radiological interventions average between 381 Euro up to 1612 Euro lower than compared with profits obtained from in patient care. (orig.)

  14. Hepatic Rupture Caused by Hemolysis, Elevated Liver Enzyme, and Low Platelet Count Syndrome: A Case Report with Computed Tomographic and Conventional Angiographic Findings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Cheong Bok; Ahn, Jae Hong; Choi, Soo Jung; Lee, Jong Hyeog; Park, Man Soo; Jung, Seung Mun; Ryu, Dae Sik [Dept. of Radiology, Asan Foundation, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung (Korea, Republic of)

    2013-03-15

    The authors recently obtained successful clinical outcome after embolization of the hepatic artery and right inferior phrenic artery in a pregnant patient with hemolysis, elevated liver enzyme, and low platelet count (HELLP) syndrome causing hepatic rupture. We report the computed tomographic and conventional angiographic findings in a case of HELLP syndrome, resulting in hepatic infarction and rupture with active bleeding.

  15. Mentorship, learning curves, and balance.

    Science.gov (United States)

    Cohen, Meryl S; Jacobs, Jeffrey P; Quintessenza, James A; Chai, Paul J; Lindberg, Harald L; Dickey, Jamie; Ungerleider, Ross M

    2007-09-01

    Professionals working in the arena of health care face a variety of challenges as their careers evolve and develop. In this review, we analyze the role of mentorship, learning curves, and balance in overcoming challenges that all such professionals are likely to encounter. These challenges can exist both in professional and personal life. As any professional involved in health care matures, complex professional skills must be mastered, and new professional skills must be acquired. These skills are both technical and judgmental. In most circumstances, these skills must be learned. In 2007, despite the continued need for obtaining new knowledge and learning new skills, the professional and public tolerance for a "learning curve" is much less than in previous decades. Mentorship is the key to success in these endeavours. The success of mentorship is two-sided, with responsibilities for both the mentor and the mentee. The benefits of this relationship must be bidirectional. It is the responsibility of both the student and the mentor to assure this bidirectional exchange of benefit. This relationship requires time, patience, dedication, and to some degree selflessness. This mentorship will ultimately be the best tool for mastering complex professional skills and maturing through various learning curves. Professional mentorship also requires that mentors identify and explicitly teach their mentees the relational skills and abilities inherent in learning the management of the triad of self, relationships with others, and professional responsibilities.Up to two decades ago, a learning curve was tolerated, and even expected, while professionals involved in healthcare developed the techniques that allowed for the treatment of previously untreatable diseases. Outcomes have now improved to the point that this type of learning curve is no longer acceptable to the public. Still, professionals must learn to perform and develop independence and confidence. The responsibility to

  16. Pulmonary arteriography by digital subtraction angiographic method in cyanotic heart disease with pulmonary stenosis or pulmonary atresia

    International Nuclear Information System (INIS)

    Kobayashi, Junjiro; Hirose, Hajime; Nakano, Susumu

    1985-01-01

    Pulmonary arteriography was performed by digital subtraction angiographic (DSA) method in 10 patients with cyanotic heart disease associated with pulmonary stenosis or pulmonary atresia. Ten patients consisted of five patients with tetralogy of Fallot, three with single ventricle and pulmonary stenosis, and two with pseudotruncus arteriosus. Hepato-clavicular position was taken in four patients. Pulmonary artery and its main branches were opacified and recognized clearly, and their diameter could be measured accurately with a small amount of contrast medium. There was a good correlation between the diameter of pulmonary artery measured by DSA and that measured by conventional pulmonary arteriography. DSA is a useful method for evaluating the size and the stenosis of pulmonary artery especially in small cyanotic infants. (author)

  17. Exercise left ventricular performance in patients with chest pain, ischemic-appearing exercise electrocardiograms, and angiographically normal coronary arteries

    International Nuclear Information System (INIS)

    Berger, H.J.; Sands, M.J.; Davies, R.A.; Wackers, F.J.; Alexander, J.; Lachman, A.S.; Williams, B.W.; Zaret, B.L.

    1981-01-01

    Left ventricular performance was evaluated using first-pass radionuclide angiocardiography in 31 patients with chest pain, an ischemic-appearing exercise electrocardiogram, and angiographically normal coronary arteries at rest and during maximal upright bicycle exercise. 201 Tl imaging was done in all patients after treadmill exercise and in selected patients after ergonovine provocation. Resting left ventricular performance was normal in all patients. An abnormal ejection fraction response to exercise was detected in 12 of 31 patients. Regional dysfunction was present during exercise in four patients, all of whom also had abnormal global responses. Three of these 12 patients and two additional patients had exercise-induced 201 Tl perfusion defects. In all nine patients who underwent ergonovine testing, there was no suggestion of coronary arterial spasm. Thus, left ventricular dysfunction during exercise, in the presence of normal resting performance, was found in a substantial number of patients with chest pain, an ischemic-appearing exercise electrocardiogram, and normal coronary arteries

  18. The relation between ankle-brachial index (ABI and coronary artery disease severity and risk factors: an angiographic study

    Directory of Open Access Journals (Sweden)

    Masoumeh Sadeghi

    2011-07-01

    Full Text Available BACKGROUND: The current study aims to determine the relation between ankle–brachialindex (ABI and angiographic findings and major cardiovascular risk factors in patients withsuspected coronary artery diseases (CAD in Isfahan.METHODS: In this cross-sectional descriptive-analytic research, patients with suspected CADwere studied. Characteristics of studied subjects including demographics, familial history, pastmedical history and atherosclerotic risk factors such as diabetes mellitus, hypertension,hyperlipidemia and smoking were obtained using a standard questionnaire. ABI was measuredin all studied patients. ABI ≤ 0.9 (ABI+ was considered as peripheral vessel disease and ABI >0.9 (ABI- was considered as normal. Then, all studied patients underwent coronary arteryangiography. The results of the questionnaire and angiographic findings were compared in ABI+and ABI- groups. Data were analyzed by SPSS 15 using ANOVA, t-test, Spearman's rankcorrelation coefficient, and discriminant analysis.RESULTS: In this study, 125 patients were investigated. ABI ≤ 0.9 was seen in 25 patients (20%.The prevalence of ABI+ among men and women was 25.9% and 7.5%, respectively (P = 0.01. Theprevalence of atherosclerotic risk factors was significantly higher in ABI+ patients than in ABIones(P < 0.05. ABI+ patients had more significant stenosis than ABI- ones. The mean ofocclusion was significantly higher in ABI+ patients with left main artery (LMA, right coronaryartery (RCA, left anterior descending artery (LAD, diagonal artery 1 (D1 and left circumflexartery (LCX involvements (P < 0.05.CONCLUSION: The findings of this research indicated that ABI could be a useful method inassessing both the atherosclerotic risk factors and the degree of coronary involvements insuspected patients. However, in order to make more accurate decisions for using this method indiagnosing and preventing CAD, we should plan further studies in large sample sizes of generalpopulation

  19. Angiographic follow-up after carotid artery stenting of bifurcation stenosis; Angiographische Verlaufskontrolle nach Stentimplantation zur Behandlung der Karotisbifurkationsstenose

    Energy Technology Data Exchange (ETDEWEB)

    Hauth, E.A.; Forsting, M. [Inst. fuer Diagnostische und Interventionelle Radiologie und Neuroradiologie, Universitaetsklinik Essen (Germany); Jansen, C.; Drescher, R.; Mathias, K. [Radiologische Klinik, Klinikum Dortmund (Germany); Schwarz, M. [Neurologische Klinik, Klinikum Dortmund (Germany); Christmann, A. [Fachbereich Statistik, Univ. Dortmund (Germany); Jaeger, H. [Radiologische Klinik, Klinikum Dortmund (Germany); Marien-Hospital Wesel, Praxis fuer Radiologie, Neuroradiologie and Nuklearmedizin (Germany)

    2006-08-15

    Purpose: the purpose of this prospective study was to determine the restenosis grade, the intima hyperplasia and the stent expansion via angiographic follow-up six months after carotid artery stenting. Materials and methods: in 100 patients, angiographic follow-up was performed 5.9 months (range: 2.9 - 11.4 months) after carotid artery stenting. The restenosis grade, the intima hyperplasia and the stent expansion were measured by selective angiography of the treated carotid artery. Results: the mean restenosis grade was 16% (range: 0 - 78%). In 6 of 100 patients (6%), a restenosis grade of > 50% was measured. In 4 patients the restenosis grade was 50 - 70%. In 2 patients the restenosis grade was > 70%. In 91 of 100 patients (91%), the restenosis was localized in the former area of stenosis of the carotid artery, and in 9 of 100 patients (9%), the restenosis was localized in the cranial stent end. The mean grade of intima hyperplasia was 31% (range: 2 - 70%). The mean increase in stent expansion at the time of follow-up was 10% (range: 0 - 59%). No correlation was able to be determined between the grade of stenosis and the grade of restenosis (rho = 0,017, range: -0.180 - 0.213), between the grade of residual stenosis and the grade of restenosis (rho = 0,257, range: 0.064 - 0.431) and between intima hyperplasia and the grade of restenosis (rho = 0,476, range: 0.309 - 0.615). Conclusions: carotid artery stenting is associated with a low incidence of high-grade restenosis 6 months after an intervention. The intima hyperplasia, which can be observed in each Wallstent, is partly compensated by the expansion of the self-expandable stent. Without a correlation between the grade of residual stenosis and the grade of restenosis, low-grade residual stenosis can be accepted. Therefore, we recommend undersized postdilation of the Wallstent. (orig.)

  20. Clinical and angiographic profile of patients with markedly elevated coronary calcium scores (≥1000) detected by electron beam computed tomography

    International Nuclear Information System (INIS)

    Almeda, Francis Q.; Shah, Rima; Senter, Shaun; Kason, Thomas T.; Haynie, Justin; Calvin, James E.; Kavinsky, Clifford J.; Snell, R. Jeffrey; Schaer, Gary L.; McLaughlin, Vallerie V.

    2004-01-01

    Objective: The objective of this study was to determine the clinical and angiographic profile of patients with extremely high coronary artery calcium scores (CACS; ≥1000) by electron beam computed tomography (EBCT). Methods: All patients at Rush University Medical Center who had a calcium score ≥1000 and a coronary angiogram performed from 1997 to 2002 were identified using a prospectively collected database. The baseline demographics, symptom status, and degree of coronary stenosis by angiography and subsequent rate of coronary intervention were compared with that of patients with calcium scores <1000. Results: The clinical and angiographic profile of patients with severe coronary calcification, detected by EBCT, revealed that patients with scores ≥1000 had a significantly higher prevalence of coronary stenosis ≥50% compared with patients with scores <1000 (97% vs. 57%, P<.001). The group with CACS ≥1000 was more likely to be male (90% vs. 75%, P=.027) and was older (64±8 vs. 59±10, P=.001) compared with the group with less severe calcification. Although there was a significantly higher rate of luminal stenosis detected by coronary angiography in the cohort with CACS ≥1000, there was no difference in subsequent percutaneous coronary intervention (PCI) and utilization of intracoronary stents between the two groups. Conclusions: A markedly elevated coronary calcium score (≥1000) is correlated with increasing age and is associated with an increased likelihood of coronary stenosis ≥50%. However, the decision to perform coronary angiography in patients with severe coronary calcification should not be based solely on these findings, but should remain primarily dependent on the degree of ischemia detected by clinical and functional assessment

  1. A novel method for the angiographic estimation of the percentage of spleen volume embolized during partial splenic embolization

    International Nuclear Information System (INIS)

    Ou, Ming-Ching; Chuang, Ming-Tsung; Lin, Xi-Zhang; Tsai, Hong-Ming; Chen, Shu-Yuan; Liu, Yi-Sheng

    2013-01-01

    Purpose: To evaluate the efficacy of estimating the volume of spleen embolized in partial splenic embolization (PSE) by measuring the diameters of the splenic artery and its branches. Materials and methods: A total of 43 liver cirrhosis patients (mean age, 62.19 ± 9.65 years) with thrombocytopenia were included. Among these, 24 patients underwent a follow-up CT scan which showed a correlation between angiographic estimation and measured embolized splenic volume. Estimated splenic embolization volume was calculated by a method based on diameters of the splenic artery and its branches. The diameters of each of the splenic arteries and branches were measured via 2D angiographic images. Embolization was performed with gelatin sponges. Patients underwent follow-up with serial measurement of blood counts and liver function tests. The actual volume of embolized spleen was determined by computed tomography (CT) measuring the volumes of embolized and non-embolized spleen two months after PSE. Results: PSE was performed without immediate major complications. The mean WBC count significantly increased from 3.81 ± 1.69 × 10 3 /mm 3 before PSE to 8.56 ± 3.14 × 10 3 /mm 3 at 1 week after PSE (P < 0.001). Mean platelet count significantly increased from 62.00 ± 22.62 × 10 3 /mm 3 before PSE to 95.40 ± 46.29 × 10 3 /mm 3 1 week after PSE (P < 0.001). The measured embolization ratio was positively correlated with estimated embolization ratio (Spearman's rho [ρ] = 0.687, P < 0.001). The mean difference between the actual embolization ratio and the estimated embolization ratio was 16.16 ± 8.96%. Conclusions: The method provides a simple method to quantitatively estimate embolized splenic volume with a correlation of measured embolization ratio to estimated embolization ratio of Spearman's ρ = 0.687

  2. A catalog of special plane curves

    CERN Document Server

    Lawrence, J Dennis

    2014-01-01

    Among the largest, finest collections available-illustrated not only once for each curve, but also for various values of any parameters present. Covers general properties of curves and types of derived curves. Curves illustrated by a CalComp digital incremental plotter. 12 illustrations.

  3. Computation of undulator tuning curves

    International Nuclear Information System (INIS)

    Dejus, Roger J.

    1997-01-01

    Computer codes for fast computation of on-axis brilliance tuning curves and flux tuning curves have been developed. They are valid for an ideal device (regular planar device or a helical device) using the Bessel function formalism. The effects of the particle beam emittance and the beam energy spread on the spectrum are taken into account. The applicability of the codes and the importance of magnetic field errors of real insertion devices are addressed. The validity of the codes has been experimentally verified at the APS and observed discrepancies are in agreement with predicted reduction of intensities due to magnetic field errors. The codes are distributed as part of the graphical user interface XOP (X-ray OPtics utilities), which simplifies execution and viewing of the results

  4. Curved canals: Ancestral files revisited

    Directory of Open Access Journals (Sweden)

    Jain Nidhi

    2008-01-01

    Full Text Available The aim of this article is to provide an insight into different techniques of cleaning and shaping of curved root canals with hand instruments. Although a plethora of root canal instruments like ProFile, ProTaper, LightSpeed ® etc dominate the current scenario, the inexpensive conventional root canal hand files such as K-files and flexible files can be used to get optimum results when handled meticulously. Special emphasis has been put on the modifications in biomechanical canal preparation in a variety of curved canal cases. This article compiles a series of clinical cases of root canals with curvatures in the middle and apical third and with S-shaped curvatures that were successfully completed by employing only conventional root canal hand instruments.

  5. Invariance for Single Curved Manifold

    KAUST Repository

    Castro, Pedro Machado Manhaes de

    2012-01-01

    Recently, it has been shown that, for Lambert illumination model, solely scenes composed by developable objects with a very particular albedo distribution produce an (2D) image with isolines that are (almost) invariant to light direction change. In this work, we provide and investigate a more general framework, and we show that, in general, the requirement for such in variances is quite strong, and is related to the differential geometry of the objects. More precisely, it is proved that single curved manifolds, i.e., manifolds such that at each point there is at most one principal curvature direction, produce invariant is surfaces for a certain relevant family of energy functions. In the three-dimensional case, the associated energy function corresponds to the classical Lambert illumination model with albedo. This result is also extended for finite-dimensional scenes composed by single curved objects. © 2012 IEEE.

  6. Invariance for Single Curved Manifold

    KAUST Repository

    Castro, Pedro Machado Manhaes de

    2012-08-01

    Recently, it has been shown that, for Lambert illumination model, solely scenes composed by developable objects with a very particular albedo distribution produce an (2D) image with isolines that are (almost) invariant to light direction change. In this work, we provide and investigate a more general framework, and we show that, in general, the requirement for such in variances is quite strong, and is related to the differential geometry of the objects. More precisely, it is proved that single curved manifolds, i.e., manifolds such that at each point there is at most one principal curvature direction, produce invariant is surfaces for a certain relevant family of energy functions. In the three-dimensional case, the associated energy function corresponds to the classical Lambert illumination model with albedo. This result is also extended for finite-dimensional scenes composed by single curved objects. © 2012 IEEE.

  7. Curved Folded Plate Timber Structures

    OpenAIRE

    Buri, Hans Ulrich; Stotz, Ivo; Weinand, Yves

    2011-01-01

    This work investigates the development of a Curved Origami Prototype made with timber panels. In the last fifteen years the timber industry has developed new, large size, timber panels. Composition and dimensions of these panels and the possibility of milling them with Computer Numerical Controlled machines shows great potential for folded plate structures. To generate the form of these structures we were inspired by Origami, the Japanese art of paper folding. Common paper tessellations are c...

  8. Projection-based curve clustering

    International Nuclear Information System (INIS)

    Auder, Benjamin; Fischer, Aurelie

    2012-01-01

    This paper focuses on unsupervised curve classification in the context of nuclear industry. At the Commissariat a l'Energie Atomique (CEA), Cadarache (France), the thermal-hydraulic computer code CATHARE is used to study the reliability of reactor vessels. The code inputs are physical parameters and the outputs are time evolution curves of a few other physical quantities. As the CATHARE code is quite complex and CPU time-consuming, it has to be approximated by a regression model. This regression process involves a clustering step. In the present paper, the CATHARE output curves are clustered using a k-means scheme, with a projection onto a lower dimensional space. We study the properties of the empirically optimal cluster centres found by the clustering method based on projections, compared with the 'true' ones. The choice of the projection basis is discussed, and an algorithm is implemented to select the best projection basis among a library of orthonormal bases. The approach is illustrated on a simulated example and then applied to the industrial problem. (authors)

  9. Growth curves for Laron syndrome.

    Science.gov (United States)

    Laron, Z; Lilos, P; Klinger, B

    1993-01-01

    Growth curves for children with Laron syndrome were constructed on the basis of repeated measurements made throughout infancy, childhood, and puberty in 24 (10 boys, 14 girls) of the 41 patients with this syndrome investigated in our clinic. Growth retardation was already noted at birth, the birth length ranging from 42 to 46 cm in the 12/20 available measurements. The postnatal growth curves deviated sharply from the normal from infancy on. Both sexes showed no clear pubertal spurt. Girls completed their growth between the age of 16-19 years to a final mean (SD) height of 119 (8.5) cm whereas the boys continued growing beyond the age of 20 years, achieving a final height of 124 (8.5) cm. At all ages the upper to lower body segment ratio was more than 2 SD above the normal mean. These growth curves constitute a model not only for primary, hereditary insulin-like growth factor-I (IGF-I) deficiency (Laron syndrome) but also for untreated secondary IGF-I deficiencies such as growth hormone gene deletion and idiopathic congenital isolated growth hormone deficiency. They should also be useful in the follow up of children with Laron syndrome treated with biosynthetic recombinant IGF-I. PMID:8333769

  10. Elementary particles in curved spaces

    International Nuclear Information System (INIS)

    Lazanu, I.

    2004-01-01

    The theories in particle physics are developed currently, in Minkowski space-time starting from the Poincare group. A physical theory in flat space can be seen as the limit of a more general physical theory in a curved space. At the present time, a theory of particles in curved space does not exist, and thus the only possibility is to extend the existent theories in these spaces. A formidable obstacle to the extension of physical models is the absence of groups of motion in more general Riemann spaces. A space of constant curvature has a group of motion that, although differs from that of a flat space, has the same number of parameters and could permit some generalisations. In this contribution we try to investigate some physical implications of the presumable existence of elementary particles in curved space. In de Sitter space (dS) the invariant rest mass is a combination of the Poincare rest mass and the generalised angular momentum of a particle and it permits to establish a correlation with the vacuum energy and with the cosmological constant. The consequences are significant because in an experiment the local structure of space-time departs from the Minkowski space and becomes a dS or AdS space-time. Discrete symmetry characteristics of the dS/AdS group suggest some arguments for the possible existence of the 'mirror matter'. (author)

  11. Dual Smarandache Curves and Smarandache Ruled Surfaces

    OpenAIRE

    Tanju KAHRAMAN; Mehmet ÖNDER; H. Hüseyin UGURLU

    2013-01-01

    In this paper, by considering dual geodesic trihedron (dual Darboux frame) we define dual Smarandache curves lying fully on dual unit sphere S^2 and corresponding to ruled surfaces. We obtain the relationships between the elements of curvature of dual spherical curve (ruled surface) x(s) and its dual Smarandache curve (Smarandache ruled surface) x1(s) and we give an example for dual Smarandache curves of a dual spherical curve.

  12. A note on families of fragility curves

    International Nuclear Information System (INIS)

    Kaplan, S.; Bier, V.M.; Bley, D.C.

    1989-01-01

    In the quantitative assessment of seismic risk, uncertainty in the fragility of a structural component is usually expressed by putting forth a family of fragility curves, with probability serving as the parameter of the family. Commonly, a lognormal shape is used both for the individual curves and for the expression of uncertainty over the family. A so-called composite single curve can also be drawn and used for purposes of approximation. This composite curve is often regarded as equivalent to the mean curve of the family. The equality seems intuitively reasonable, but according to the authors has never been proven. The paper presented proves this equivalence hypothesis mathematically. Moreover, the authors show that this equivalence hypothesis between fragility curves is itself equivalent to an identity property of the standard normal probability curve. Thus, in the course of proving the fragility curve hypothesis, the authors have also proved a rather obscure, but interesting and perhaps previously unrecognized, property of the standard normal curve

  13. Observable Zitterbewegung in curved spacetimes

    Science.gov (United States)

    Kobakhidze, Archil; Manning, Adrian; Tureanu, Anca

    2016-06-01

    Zitterbewegung, as it was originally described by Schrödinger, is an unphysical, non-observable effect. We verify whether the effect can be observed in non-inertial reference frames/curved spacetimes, where the ambiguity in defining particle states results in a mixing of positive and negative frequency modes. We explicitly demonstrate that such a mixing is in fact necessary to obtain the correct classical value for a particle's velocity in a uniformly accelerated reference frame, whereas in cosmological spacetime a particle does indeed exhibit Zitterbewegung.

  14. Observable Zitterbewegung in curved spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Kobakhidze, Archil, E-mail: archilk@physics.usyd.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Sydney, NSW 2006 (Australia); Manning, Adrian, E-mail: a.manning@physics.usyd.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, The University of Sydney, NSW 2006 (Australia); Tureanu, Anca, E-mail: anca.tureanu@helsinki.fi [Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki (Finland)

    2016-06-10

    Zitterbewegung, as it was originally described by Schrödinger, is an unphysical, non-observable effect. We verify whether the effect can be observed in non-inertial reference frames/curved spacetimes, where the ambiguity in defining particle states results in a mixing of positive and negative frequency modes. We explicitly demonstrate that such a mixing is in fact necessary to obtain the correct classical value for a particle's velocity in a uniformly accelerated reference frame, whereas in cosmological spacetime a particle does indeed exhibit Zitterbewegung.

  15. Differential geometry curves, surfaces, manifolds

    CERN Document Server

    Kohnel, Wolfgang

    2002-01-01

    This carefully written book is an introduction to the beautiful ideas and results of differential geometry. The first half covers the geometry of curves and surfaces, which provide much of the motivation and intuition for the general theory. Special topics that are explored include Frenet frames, ruled surfaces, minimal surfaces and the Gauss-Bonnet theorem. The second part is an introduction to the geometry of general manifolds, with particular emphasis on connections and curvature. The final two chapters are insightful examinations of the special cases of spaces of constant curvature and Einstein manifolds. The text is illustrated with many figures and examples. The prerequisites are undergraduate analysis and linear algebra.

  16. LINS Curve in Romanian Economy

    Directory of Open Access Journals (Sweden)

    Emilian Dobrescu

    2016-02-01

    Full Text Available The paper presents theoretical considerations and empirical evidence to test the validity of the Laffer in Narrower Sense (LINS curve as a parabola with a maximum. Attention is focused on the so-called legal-effective tax gap (letg. The econometric application is based on statistical data (1990-2013 for Romania as an emerging European economy. Three cointegrating regressions (fully modified least squares, canonical cointegrating regression and dynamic least squares and three algorithms, which are based on instrumental variables (two-stage least squares, generalized method of moments, and limited information maximum likelihood, are involved.

  17. Differential geometry and topology of curves

    CERN Document Server

    Animov, Yu

    2001-01-01

    Differential geometry is an actively developing area of modern mathematics. This volume presents a classical approach to the general topics of the geometry of curves, including the theory of curves in n-dimensional Euclidean space. The author investigates problems for special classes of curves and gives the working method used to obtain the conditions for closed polygonal curves. The proof of the Bakel-Werner theorem in conditions of boundedness for curves with periodic curvature and torsion is also presented. This volume also highlights the contributions made by great geometers. past and present, to differential geometry and the topology of curves.

  18. Plasma α1-antitrypsin: A Neglected Predictor of Angiographic Severity in Patients with Stable Angina Pectoris

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    2015-01-01

    Full Text Available Background: As an acute phase protein, α1-antitrypsin (AAT has been extensively studied in acute coronary syndrome, but it is unclear whether a relationship exists between AAT and stable angina pectoris (SAP. The purpose of the present study was to investigate the association between AAT plasma levels and SAP. Methods: Overall, 103 SAP patients diagnosed by coronary angiography and clinical manifestations and 118 control subjects matched for age and gender were enrolled in this case-control study. Plasma levels of AAT, high-sensitivity C-reactive protein (hsCRP, lipid profiles and other clinical parameters were assayed for all participants. The severity of coronary lesions was evaluated based on the Gensini score (GS assessed by coronary angiography. Results: Positively correlated with the GS (r = 0.564, P < 0.001, the plasma AAT level in the SAP group was significantly higher than that in the control group (142.08 ± 19.61 mg/dl vs. 125.50 ± 19.67 mg/dl, P < 0.001. The plasma AAT level was an independent predictor for both SAP (odds ratio [OR] = 1.037, 95% confidence interval [CI]: 1.020-1.054, P < 0.001 and a high GS (OR = 1.087, 95% CI: 1.051-1.124, P < 0.001 in a multivariate logistic regression model. In the receiver operating characteristic curve analysis, plasma AAT level was found to have a larger area under the curve (AUC for predicting a high GS (AUC = 0.858, 95% CI: 0.788-0.929, P < 0.001 than that of hsCRP (AUC = 0.665, 95% CI: 0.557-0.773, P = 0.006; Z = 2.9363, P < 0.001, with an optimal cut-off value of 137.85 mg/dl (sensitivity: 94.3%, specificity: 68.2%. Conclusions: Plasma AAT levels correlate with both the presence and severity of coronary stenosis in patients with SAP, suggesting that it could be a potential predictive marker of severe stenosis in SAP patients.

  19. Plasma α1-antitrypsin: A Neglected Predictor of Angiographic Severity in Patients with Stable Angina Pectoris

    Science.gov (United States)

    Zhao, Hui; Liu, Hong; Chai, Lin; Xu, Ping; Hua, Lu; Guan, Xiao-Yuan; Duan, Bing; Huang, Yi-Ling; Li, Yi-Shi

    2015-01-01

    Background: As an acute phase protein, α1-antitrypsin (AAT) has been extensively studied in acute coronary syndrome, but it is unclear whether a relationship exists between AAT and stable angina pectoris (SAP). The purpose of the present study was to investigate the association between AAT plasma levels and SAP. Methods: Overall, 103 SAP patients diagnosed by coronary angiography and clinical manifestations and 118 control subjects matched for age and gender were enrolled in this case-control study. Plasma levels of AAT, high-sensitivity C-reactive protein (hsCRP), lipid profiles and other clinical parameters were assayed for all participants. The severity of coronary lesions was evaluated based on the Gensini score (GS) assessed by coronary angiography. Results: Positively correlated with the GS (r = 0.564, P < 0.001), the plasma AAT level in the SAP group was significantly higher than that in the control group (142.08 ± 19.61 mg/dl vs. 125.50 ± 19.67 mg/dl, P < 0.001). The plasma AAT level was an independent predictor for both SAP (odds ratio [OR] = 1.037, 95% confidence interval [CI]: 1.020–1.054, P < 0.001) and a high GS (OR = 1.087, 95% CI: 1.051–1.124, P < 0.001) in a multivariate logistic regression model. In the receiver operating characteristic curve analysis, plasma AAT level was found to have a larger area under the curve (AUC) for predicting a high GS (AUC = 0.858, 95% CI: 0.788–0.929, P < 0.001) than that of hsCRP (AUC = 0.665, 95% CI: 0.557–0.773, P = 0.006; Z = 2.9363, P < 0.001), with an optimal cut-off value of 137.85 mg/dl (sensitivity: 94.3%, specificity: 68.2%). Conclusions: Plasma AAT levels correlate with both the presence and severity of coronary stenosis in patients with SAP, suggesting that it could be a potential predictive marker of severe stenosis in SAP patients. PMID:25758268

  20. Flow characteristics of curved ducts

    Directory of Open Access Journals (Sweden)

    Rudolf P.

    2007-10-01

    Full Text Available Curved channels are very often present in real hydraulic systems, e.g. curved diffusers of hydraulic turbines, S-shaped bulb turbines, fittings, etc. Curvature brings change of velocity profile, generation of vortices and production of hydraulic losses. Flow simulation using CFD techniques were performed to understand these phenomena. Cases ranging from single elbow to coupled elbows in shapes of U, S and spatial right angle position with circular cross-section were modeled for Re = 60000. Spatial development of the flow was studied and consequently it was deduced that minor losses are connected with the transformation of pressure energy into kinetic energy and vice versa. This transformation is a dissipative process and is reflected in the amount of the energy irreversibly lost. Least loss coefficient is connected with flow in U-shape elbows, biggest one with flow in Sshape elbows. Finally, the extent of the flow domain influenced by presence of curvature was examined. This isimportant for proper placement of mano- and flowmeters during experimental tests. Simulations were verified with experimental results presented in literature.

  1. Improved capacitive melting curve measurements

    International Nuclear Information System (INIS)

    Sebedash, Alexander; Tuoriniemi, Juha; Pentti, Elias; Salmela, Anssi

    2009-01-01

    Sensitivity of the capacitive method for determining the melting pressure of helium can be enhanced by loading the empty side of the capacitor with helium at a pressure nearly equal to that desired to be measured and by using a relatively thin and flexible membrane in between. This way one can achieve a nanobar resolution at the level of 30 bar, which is two orders of magnitude better than that of the best gauges with vacuum reference. This extends the applicability of melting curve thermometry to lower temperatures and would allow detecting tiny anomalies in the melting pressure, which must be associated with any phenomena contributing to the entropy of the liquid or solid phases. We demonstrated this principle in measurements of the crystallization pressure of isotopic helium mixtures at millikelvin temperatures by using partly solid pure 4 He as the reference substance providing the best possible universal reference pressure. The achieved sensitivity was good enough for melting curve thermometry on mixtures down to 100 μK. Similar system can be used on pure isotopes by virtue of a blocked capillary giving a stable reference condition with liquid slightly below the melting pressure in the reference volume. This was tested with pure 4 He at temperatures 0.08-0.3 K. To avoid spurious heating effects, one must carefully choose and arrange any dielectric materials close to the active capacitor. We observed some 100 pW loading at moderate excitation voltages.

  2. Classical optics and curved spaces

    International Nuclear Information System (INIS)

    Bailyn, M.; Ragusa, S.

    1976-01-01

    In the eikonal approximation of classical optics, the unit polarization 3-vector of light satisfies an equation that depends only on the index, n, of refraction. It is known that if the original 3-space line element is d sigma 2 , then this polarization direction propagates parallely in the fictitious space n 2 d sigma 2 . Since the equation depends only on n, it is possible to invent a fictitious curved 4-space in which the light performs a null geodesic, and the polarization 3-vector behaves as the 'shadow' of a parallely propagated 4-vector. The inverse, namely, the reduction of Maxwell's equation, on a curve 'dielectric free) space, to a classical space with dielectric constant n=(-g 00 ) -1 / 2 is well known, but in the latter the dielectric constant epsilon and permeability μ must also equal (-g 00 ) -1 / 2 . The rotation of polarization as light bends around the sun by utilizing the reduction to the classical space, is calculated. This (non-) rotation may then be interpreted as parallel transport in the 3-space n 2 d sigma 2 [pt

  3. Right atrial angiographic evaluation of the posterior isthmus: relevance for ablation of typical atrial flutter.

    Science.gov (United States)

    Heidbüchel, H; Willems, R; van Rensburg, H; Adams, J; Ector, H; Van de Werf, F

    2000-05-09

    Gaining anatomic information about the posterior isthmus is not generally part of flutter ablation procedures. We postulated that right atrial (RA) angiography could rationalize the ablation approach by revealing the conformation of the isthmus. In 100 consecutive patients, biplane RA angiography was performed before ablation to guide catheter contact with the isthmus along its length. Angiography showed a wide variation in the width of the isthmus (17 to 54 mm; 31.3+/-7.9), its angle with the inferior vena cava in the right anterior oblique projection (68 degrees to 114 degrees; 90.3+/-9.0 degrees ), and its lateral position relative to the inferior vena cava in the left anterior oblique projection. A deep sub-Eustachian recess was revealed in 47%, with a mean depth of 4.3+/-2.1 mm (1.5 to 9.4). A Eustachian valve was visualized in 24%. Ablation resulted in bidirectional conduction block (which could be transient) in all, with a median of 2 dragging radiofrequency (RF) applications (2.3+/-2.5 RF applications; 57 degrees C, deep pouches. The number of RF applications decreased statistically throughout the study, indicating a learning curve. No patient had a recurrence after a follow-up of 13+/-11 months. Right atrial angiography reveals a highly variable isthmus anatomy, often showing particular configurations that can make ablation more laborious. Rational adaptation of the ablation approach to these anatomic findings may contribute to successful ablation.

  4. Clinical characteristics, angiographic profile and in hospital mortality in acute coronary syndrome patients in south indian population

    Directory of Open Access Journals (Sweden)

    Rajni Sharma

    2014-01-01

    Full Text Available Aims: The aim was to study the clinical profile, risk factors prevalence, angiographic distribution, and severity of coronary artery stenosis in acute coronary syndrome (ACS patients of South Indian population. Materials and Methods: A total of 1562 patients of ACS were analyzed for various risk factors, angiographic pattern and severity of coronary heart disease, complications and in hospital mortality at Sri Jayadeva Institute of Cardiovascular Research and Sciences, Bengaluru, Karnataka, India. Results: Mean age of presentation was 54.71 ± 19.90 years. Majority were male 1242 (79.5% and rest were females. Most patients had ST elevation myocardial infarction (STEMI 995 (63.7% followed by unstable angina (UA 390 (25% and non-STEMI (NSTEMI 177 (11.3%. Risk factors; smoking was present in 770 (49.3%, hypertension in 628 (40.2%, diabetes in 578 (37%, and obesity in (29.64% patients. Angiography was done in 1443 (92.38% patients. left anterior descending was most commonly involved, left main (LM coronary artery was least common with near similar frequency of right coronary artery and left circumflex involvement among all three groups of ACS patients. Single-vessel disease was present in 168 (45.28% UA, 94 (56.29% NSTEMI and 468 (51.71% STEMI patients. Double-vessel disease was present in 67 (18.08% UA, 25 (14.97% NSTEMI and 172 (19.01% STEMI patients. Triple vessel disease was present in 28 (7.55% UA, 16 (9.58% NSTEMI, 72 (7.95% STEMI patients. LM disease was present in 12 (3.23% UA, 2 (1.19% NSTEMI and 9 (0.99% STEMI patients. Complications; ventricular septal rupture occurred in 3 (0.2%, free wall rupture in 2 (0.1%, cardiogenic shock in 45 (2.9%, severe mitral regurgitation in 3 (0.2%, complete heart block in 11 (0.7% patients. Total 124 (7.9% patients died in hospital after 2.1 ± 1.85 days of admission. Conclusion: STEMI was most common presentation. ACS occurred a decade earlier in comparison to Western population. Smoking was most prevalent

  5. WE-E-18A-09: Application of a Channelized Hotelling Observer Model to Evaluate Angiographic Imaging Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Favazza, C; Fetterly, K; Hangiandreou, N; Leng, S; Schueler, B [Mayo Clinic, Rochester, MN (United States)

    2014-06-15

    Purpose: To develop and apply an observer model to objectively evaluate and compare the performance of different angiographic imaging equipment and acquisition variables. Methods: Image Acquisition— Iodine-based phantoms were created with target diameters: 0.5, 1, 2, and 4 mm. The phantoms were imaged using both planes of a bi-plane angiography system with detector pixel dimensions 0.1542 mm{sup 2} and 0.1842 mm{sup 2}, respectively. All four phantoms were imaged with magnification factors 1.5, 1.25 and 1 and with the large and small focal spots. Phantom position and the dose per frame (0.12– 0.24 μ Gy/frame) were varied for a single phantom size, magnification and focal spot. Observer Model— For each experimental condition, 1200 signal-present and signal-absent images were acquired and a detectability index (d') was calculated with a Gabor-channelized Hotelling observer (CHO) model. Detectability indices were evaluated as a function of dose, phantom size, and magnification. The model was then applied to compare d' of the two imaging planes and focal spots. Uncertainty in d' was estimated by bootstrapping the data and by examining the shift-variance of systems. Results: Detectability indices varied linearly with magnification and the square root of dose. For the 2 and 4 mm phantoms, d' varied linearly with diameter. For the 0.5 and 1 mm phantoms, d' expectedly deviated from this linear relationship due to substantial detector and focal spot blurring of the phantoms. The small focal spot yielded up to 50% greater d' values than the large focal spot. For the two detectors, differences in d' did not exceed the estimated ∼7% error. Conclusions: The detectability indices predictably scaled with dose, diameter, magnification, and focal spot size and serve to validate the model. Results demonstrate statistically similar target detectability for both investigated detectors, despite differences in pixel dimensions. This CHO model

  6. WE-E-18A-09: Application of a Channelized Hotelling Observer Model to Evaluate Angiographic Imaging Equipment

    International Nuclear Information System (INIS)

    Favazza, C; Fetterly, K; Hangiandreou, N; Leng, S; Schueler, B

    2014-01-01

    Purpose: To develop and apply an observer model to objectively evaluate and compare the performance of different angiographic imaging equipment and acquisition variables. Methods: Image Acquisition— Iodine-based phantoms were created with target diameters: 0.5, 1, 2, and 4 mm. The phantoms were imaged using both planes of a bi-plane angiography system with detector pixel dimensions 0.1542 mm 2 and 0.1842 mm 2 , respectively. All four phantoms were imaged with magnification factors 1.5, 1.25 and 1 and with the large and small focal spots. Phantom position and the dose per frame (0.12– 0.24 μ Gy/frame) were varied for a single phantom size, magnification and focal spot. Observer Model— For each experimental condition, 1200 signal-present and signal-absent images were acquired and a detectability index (d') was calculated with a Gabor-channelized Hotelling observer (CHO) model. Detectability indices were evaluated as a function of dose, phantom size, and magnification. The model was then applied to compare d' of the two imaging planes and focal spots. Uncertainty in d' was estimated by bootstrapping the data and by examining the shift-variance of systems. Results: Detectability indices varied linearly with magnification and the square root of dose. For the 2 and 4 mm phantoms, d' varied linearly with diameter. For the 0.5 and 1 mm phantoms, d' expectedly deviated from this linear relationship due to substantial detector and focal spot blurring of the phantoms. The small focal spot yielded up to 50% greater d' values than the large focal spot. For the two detectors, differences in d' did not exceed the estimated ∼7% error. Conclusions: The detectability indices predictably scaled with dose, diameter, magnification, and focal spot size and serve to validate the model. Results demonstrate statistically similar target detectability for both investigated detectors, despite differences in pixel dimensions. This CHO model provides

  7. Correlation between scatter radiation dose at height of operator's eye and dose to patient for different angiographic projections

    International Nuclear Information System (INIS)

    Leyton, Fernando; Nogueira, Maria S.; Gubolino, Luiz A.; Pivetta, Makyson R.; Ubeda, Carlos

    2016-01-01

    Studies have reported cases of radiation-induced cataract among cardiology professionals. In view of the evidence of epidemiological studies, the ICRP recommends a new threshold for opacities and a new radiation dose to eye lens limit of 20 mSv per year for occupational exposure. The aim of this paper is to report scattered radiation doses at the height of the operator's eye in an interventional cardiology facility without considering radiation protection devices and to correlate these values with different angiographic projections and operational modes. Measurements were taken in a cardiac laboratory with an angiography X-ray system equipped with flat-panel detector. PMMA plates of 30×30×5 cm were used with a thickness of 20 cm. Measurements were taken in two fluoroscopy modes (low and normal, 15 pulses/s) and in cine mode (15 frames/s). Four angiographic projections were used: anterior posterior; lateral; left anterior oblique caudal (spider); and left anterior oblique cranial, with a cardiac protocol for patients weighing between 70 and 90 kg. Measurements of phantom entrance dose rate and scatter dose rate were performed with two Unfors Xi plus detectors. The detector measuring scatter radiation was positioned at the usual distance of the cardiologist's eyes during working conditions. There is a good linear correlation between the kerma area product and scatter dose at the lens. Experimental correlation factors of 2.3, 12.0, 12.2 and 17.6 μSv/Gy cm2 were found for different projections. PMMA entrance dose rates for low and medium fluoroscopy and cine modes were 13, 39 and 282 mGy/min, respectively, for AP projection. - Highlights: • A method is presented to estimate the scatter radiation dose at operator eye height. • The method allows estimating scatter radiation dose measuring ambient dose equivalent. • Operator could exceed threshold for lens opacities if protection tools are not used. • There is a good linear correlation between kerma

  8. A novel method for the angiographic estimation of the percentage of spleen volume embolized during partial splenic embolization

    Energy Technology Data Exchange (ETDEWEB)

    Ou, Ming-Ching; Chuang, Ming-Tsung [Department of Diagnostic Radiology, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China); Lin, Xi-Zhang [Department of Internal Medicine, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China); Tsai, Hong-Ming; Chen, Shu-Yuan [Department of Diagnostic Radiology, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China); Liu, Yi-Sheng, E-mail: taicheng100704@yahoo.com.tw [Department of Diagnostic Radiology, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China)

    2013-08-15

    Purpose: To evaluate the efficacy of estimating the volume of spleen embolized in partial splenic embolization (PSE) by measuring the diameters of the splenic artery and its branches. Materials and methods: A total of 43 liver cirrhosis patients (mean age, 62.19 ± 9.65 years) with thrombocytopenia were included. Among these, 24 patients underwent a follow-up CT scan which showed a correlation between angiographic estimation and measured embolized splenic volume. Estimated splenic embolization volume was calculated by a method based on diameters of the splenic artery and its branches. The diameters of each of the splenic arteries and branches were measured via 2D angiographic images. Embolization was performed with gelatin sponges. Patients underwent follow-up with serial measurement of blood counts and liver function tests. The actual volume of embolized spleen was determined by computed tomography (CT) measuring the volumes of embolized and non-embolized spleen two months after PSE. Results: PSE was performed without immediate major complications. The mean WBC count significantly increased from 3.81 ± 1.69 × 10{sup 3}/mm{sup 3} before PSE to 8.56 ± 3.14 × 10{sup 3}/mm{sup 3} at 1 week after PSE (P < 0.001). Mean platelet count significantly increased from 62.00 ± 22.62 × 10{sup 3}/mm{sup 3} before PSE to 95.40 ± 46.29 × 10{sup 3}/mm{sup 3} 1 week after PSE (P < 0.001). The measured embolization ratio was positively correlated with estimated embolization ratio (Spearman's rho [ρ] = 0.687, P < 0.001). The mean difference between the actual embolization ratio and the estimated embolization ratio was 16.16 ± 8.96%. Conclusions: The method provides a simple method to quantitatively estimate embolized splenic volume with a correlation of measured embolization ratio to estimated embolization ratio of Spearman's ρ = 0.687.

  9. Five-year clinical and functional multislice computed tomography angiographic results after coronary implantation of the fully resorbable polymeric everolimus-eluting scaffold in patients with de novo coronary artery disease

    DEFF Research Database (Denmark)

    Onuma, Yoshinobu; Dudek, Dariusz; Thuesen, Leif

    2013-01-01

    This study sought to demonstrate the 5-year clinical and functional multislice computed tomography angiographic results after implantation of the fully resorbable everolimus-eluting scaffold (Absorb BVS, Abbott Vascular, Santa Clara, California).......This study sought to demonstrate the 5-year clinical and functional multislice computed tomography angiographic results after implantation of the fully resorbable everolimus-eluting scaffold (Absorb BVS, Abbott Vascular, Santa Clara, California)....

  10. Atlas of stress-strain curves

    CERN Document Server

    2002-01-01

    The Atlas of Stress-Strain Curves, Second Edition is substantially bigger in page dimensions, number of pages, and total number of curves than the previous edition. It contains over 1,400 curves, almost three times as many as in the 1987 edition. The curves are normalized in appearance to aid making comparisons among materials. All diagrams include metric (SI) units, and many also include U.S. customary units. All curves are captioned in a consistent format with valuable information including (as available) standard designation, the primary source of the curve, mechanical properties (including hardening exponent and strength coefficient), condition of sample, strain rate, test temperature, and alloy composition. Curve types include monotonic and cyclic stress-strain, isochronous stress-strain, and tangent modulus. Curves are logically arranged and indexed for fast retrieval of information. The book also includes an introduction that provides background information on methods of stress-strain determination, on...

  11. Transition curves for highway geometric design

    CERN Document Server

    Kobryń, Andrzej

    2017-01-01

    This book provides concise descriptions of the various solutions of transition curves, which can be used in geometric design of roads and highways. It presents mathematical methods and curvature functions for defining transition curves. .

  12. Comparison and evaluation of mathematical lactation curve ...

    African Journals Online (AJOL)

    p2492989

    A mathematical model of the lactation curve provides summary information about culling and milking strategies ..... Table 2 Statistics of the edited data for first lactation Holstein cows ..... Application of different models to the lactation curves of.

  13. Prediction of optimal deployment projection for transcatheter aortic valve replacement: angiographic 3-dimensional reconstruction of the aortic root versus multidetector computed tomography.

    OpenAIRE

    Binder Ronald K; Leipsic Jonathon; Wood David; Moore Teri; Toggweiler Stefan; Willson Alex; Gurvitch Ronen; Freeman Melanie; Webb John G

    2012-01-01

    BACKGROUND Identifying the optimal fluoroscopic projection of the aortic valve is important for successful transcatheter aortic valve replacement (TAVR). Various imaging modalities including multidetector computed tomography (MDCT) have been proposed for prediction of the optimal deployment projection. We evaluated a method that provides 3 dimensional angiographic reconstructions (3DA) of the aortic root for prediction of the optimal deployment angle and compared it with MDCT. METHODS AND RES...

  14. [Multidisciplinary protocol for computed tomography imaging and angiographic embolization of splenic injury due to trauma: assessment of pre-protocol and post-protocol outcomes].

    Science.gov (United States)

    Koo, M; Sabaté, A; Magalló, P; García, M A; Domínguez, J; de Lama, M E; López, S

    2011-11-01

    To assess conservative treatment of splenic injury due to trauma, following a protocol for computed tomography (CT) and angiographic embolization. To quantify the predictive value of CT for detecting bleeding and need for embolization. The care protocol developed by the multidisciplinary team consisted of angiography with embolization of lesions revealed by contrast extravasation under CT as well as embolization of grade III-V injuries observed, or grade I-II injuries causing hemodynamic instability and/or need for blood transfusion. We collected data on demographic variables, injury severity score (ISS), angiographic findings, and injuries revealed by CT. Pre-protocol and post-protocol outcomes were compared. The sensitivity and specificity of CT findings were calculated for all patients who required angiographic embolization. Forty-four and 30 angiographies were performed in the pre- and post-protocol periods, respectively. The mean (SD) ISSs in the two periods were 25 (11) and 26 (12), respectively. A total of 24 (54%) embolizations were performed in the pre-protocol period and 28 (98%) after implementation of the protocol. Two and 7 embolizations involved the spleen in the 2 periods, respectively; abdominal laparotomies numbered 32 and 25, respectively, and 10 (31%) vs 4 (16%) splenectomies were performed. The specificity and sensitivity values for contrast extravasation found on CT and followed by embolization were 77.7% and 79.5%. The implementation of this multidisciplinary protocol using CT imaging and angiographic embolization led to a decrease in the number of splenectomies. The protocol allows us to take a more conservative treatment approach.

  15. Quantitative stress-redistribution planar T1-201 scintigraphy: Assessment of the extent of hypoperfused myocardium by relationship to angiographic findings

    International Nuclear Information System (INIS)

    Bassir, R.; Maddahi, J.; Garcia, E.

    1984-01-01

    The size of hypoperfused myocardium (HM) in coronary artery (CA) disease (D) potentially provides a prognostic index that may not be accurately assess by conventional angiographic classification. The authors studied 62 consecutive patients (pts) with planar stress-redistribution T1-201 scintigraphy (T1-201) and coronary arteriography who did not have prior myocardial infarction and achieved 85% predicted maximum heart rate on exercise. Of 62 pts, 42 had CAD (>50% stenosis). For T1-201 quantification of the size of HM, maximum count circumferential profiles of initial distribution and % washout were obtained and compared to previously established normal limits. The area enclosed between the normal limits and the abnormal portion of the pt's profiles represented a quantitative T1-201 jeopardy score (JS). Despite increasing T1-201 JS from 1 to 3 vessel (V) and left-main (LM) D, significant overlap between the different angiographic groups was observed; of 45 pts with mild JS (<300), 14 (31%) had 3VD and/or LMD. The angiographic extent of CAD was also analyzed using a method (CLASS) proposed by Gensini et al based on the CA territory, location and severity of stenosis, and collateral circulation. T1-201 JS correlated significantly with CLASS (r=.78, p<.01). Of the 45 pts with mild JS, only 5 (11%) had severe CLASS score. Thus, the size of the hypoperfused myocardium by quantitative stress- and redistribution T1-201 correlates better with a more complex angiographic estimate of myocardium at risk than conventional 1, 2, and 3 vessel disease classification

  16. Angiographic Validation of the American College of Cardiology Foundation–The Society of Thoracic Surgeons Collaboration on the Comparative Effectiveness of Revascularization Strategies Study

    Science.gov (United States)

    Chakrabarti, Anjan K.; Grau-Sepulveda, Maria V.; O’Brien, Sean; Abueg, Cassandra; Ponirakis, Angelo; Delong, Elizabeth; Peterson, Eric; Klein, Lloyd W.; Garratt, Kirk N.; Weintraub, William S.; Gibson, C. Michael

    2017-01-01

    Background The goal of this study was to compare angiographic interpretation of coronary arteriograms by sites in community practice versus those made by a centralized angiographic core laboratory. Methods and Results The study population consisted of 2013 American College of Cardiology–National Cardiovascular Data Registry (ACC–NCDR) records with 2- and 3- vessel coronary disease from 54 sites in 2004 to 2007. The primary analysis compared Registry (NCDR)-defined 2- and 3-vessel disease versus those from an angiographic core laboratory analysis. Vessel-level kappa coefficients suggested moderate agreement between NCDR and core laboratory analysis, ranging from kappa=0.39 (95% confidence intervals, 0.32–0.45) for the left anterior descending artery to kappa=0.59 (95% confidence intervals, 0.55–0.64) for the right coronary artery. Overall, 6.3% (n=127 out of 2013) of those patients identified with multivessel disease at NCDR sites had had 0- or 1-vessel disease by core laboratory reading. There was no directional bias with regard to overcall, that is, 12.3% of cases read as 3-vessel disease by the sites were read as <3-vessel disease by the core laboratory, and 13.9% of core laboratory 3-vessel cases were read as <3-vessel by the sites. For a subset of patients with left main coronary disease, registry overcall was not linked to increased rates of mortality or myocardial infarction. Conclusions There was only modest agreement between angiographic readings in clinical practice and those from an independent core laboratory. Further study will be needed because the implications for patient management are uncertain. PMID:24496239

  17. Long-term clinical and angiographic results of Sirolimus-Eluting Stent in Complex Coronary Chronic Total Occlusion Revascularization: the SECTOR registry.

    Science.gov (United States)

    Galassi, Alfredo R; Tomasello, Salvatore D; Costanzo, Luca; Campisano, Maria B; Barrano, Giombattista; Tamburino, Corrado

    2011-10-01

    Drug-eluting stents showed a better angiographic and clinical outcome in comparison with bare metal stent in chronic total occlusions (CTOs) percutaneous revascularization, however, great concerns still remain regarding the rate of restenosis and reocclusion in comparison with nonocclusive lesions. To evaluate angiographic and clinical outcomes after sirolimus-eluting stent (SES) implantation in the setting of a "real world" series of complex CTOs. From January 2006 to December 2008, 172 consecutive patients with 179 CTO lesions were enrolled into registry. Among these, successful recanalization was obtained in 144 lesions (80.4%) with exclusive SES implantation in 104 lesions. The 9-12 months angiographic follow-up was executed in 85.5% of lesions with evidence of angiographic binary restenosis in 16.8% of lesions. Total stent length and number of stent implanted were recognized as independent predictors of restenosis (odds ratio [OR] 4.7, 95% confidence interval [CI] 1.28-107.09, P = 0.02) and (OR 5.8, 95% CI 1.39-23.55, P = 0.01), respectively.The 2-year clinical follow-up showed rates of target lesion revascularization, non-Q wave myocardial infarction, and total major adverse cardiovascular events (MACEs) of 11.1%, 2%, and 13.1%, respectively. Cox proportional-hazard analysis showed diabetes as independent predictor of MACEs (hazard ratio [HR] 4.832; 95% CI, 0.730-0.861; P = 0.028). Data from this registry demonstrate the long-term efficacy and safety of SES implantation after complex CTOs recanalization. ©2011, Wiley Periodicals, Inc.

  18. Simultaneous occurrence of a severe Morel-Lavallée lesion and gluteal muscle necrosis as a sequela of transcatheter angiographic embolization following pelvic fracture: a case report.

    Science.gov (United States)

    Shimizu, Takayoshi; Matsuda, Shuichi; Sakuragi, Atsushi; Tsukie, Tomio; Kawanabe, Keiichi

    2015-03-26

    Morel-Lavallée lesions are posttraumatic hemolymphatic collections caused by disruption of the interfascial planes between the subcutaneous soft tissue and muscle. Severe peripelvic Morel-Lavallée lesions have rarely been reported in the literature. By contrast, a number of cases of gluteal muscle necrosis following transcatheter angiographic embolization for pelvic fracture have been reported. Each entity can result in severe infection and sepsis, and the mortality rate in such cases is quite high. However, to date, no previous reports have described a case in which these life-threatening entities occurred simultaneously. A 32-year-old Asian man simultaneously developed severe peripelvic Morel-Lavallée lesions and gluteal muscle necrosis with sepsis following transcatheter angiographic embolization after an unstable pelvic fracture. Extremely large skin and soft tissue defects, which were untreatable with any commonly used flaps, were generated after repeated debridement. In addition, a deep-bone infection was suspected in his left fractured iliac bone, while motor function was almost completely lost in his left leg, possibly as a sequela of transcatheter angiographic embolization. As a result of his condition, a left hemipelvectomy was unavoidable. A pedicled fillet flap from his sacrificed left limb was used for the treatment of the defects and to provide a durable base for a prosthesis. Our patient survived and returned to his previous job 24 months after the surgery wearing a prosthetic left leg. As illustrated by the present case, severe peripelvic Morel-Lavallée lesions and gluteal muscle necrosis following transcatheter angiographic embolization can occur simultaneously after unstable pelvic fractures. Physicians should recognize that these entities can result in life-threatening sepsis and, therefore, should attempt to detect them as early as possible. When hemipelvectomy is unavoidable, a pedicled upper and lower leg in-continuity fillet flap may

  19. Influence of angiographic collateral circulation on myocardial perfusion in patients with chronic total occlusion of a single coronary artery and no prior myocardial infarction.

    Science.gov (United States)

    Aboul-Enein, Fatma; Kar, Saibal; Hayes, Sean W; Sciammarella, Maria; Abidov, Aiden; Makkar, Raj; Friedman, John D; Eigler, Neal; Berman, Daniel S

    2004-06-01

    The functional role of various angiographic grades for coronary collaterals remains controversial. The aim of this study was to assess the influence of the Rentrop angiographic grading of coronary collaterals on myocardial perfusion in patients with single-vessel chronic total occlusion (CTO) and no prior myocardial infarction (MI). The study included 56 patients with single-vessel CTO and no prior MI who underwent rest-stress myocardial perfusion SPECT and coronary angiography within 6 mo. All patients had angiographic evidence of coronary collaterals. Patients were divided according to the Rentrop classification: Group I had grade 1 or 2 (n = 25) and group II had grade 3 collaterals (n = 31). Group I had a higher frequency of resting regional wall motion abnormalities on left ventriculography (52.6% vs. 19.2% [P = 0.019]). The mean perfusion scores of the overall population showed severe and extensive stress perfusion defects (summed stress score of 14.1 +/- 7.1 and summed difference score of 12.9 +/- 6.9) but minimal resting perfusion defects (summed rest score of 1.0 +/- 2.7). No perfusion scores differed between the 2 groups. The perfusion findings suggested that chronic stunning rather than hibernation is the principal cause of regional wall motion abnormalities in these patients. In the setting of single-vessel CTO and no prior MI, coronary collaterals appear to protect against resting perfusion defects. Excellent angiographic collaterals may prevent resting regional wall motion abnormalities but do not appear to protect against stress-induced perfusion defects.

  20. Angiographic validation of the American College of Cardiology Foundation-the Society of Thoracic Surgeons Collaboration on the Comparative Effectiveness of Revascularization Strategies study.

    Science.gov (United States)

    Chakrabarti, Anjan K; Grau-Sepulveda, Maria V; O'Brien, Sean; Abueg, Cassandra; Ponirakis, Angelo; Delong, Elizabeth; Peterson, Eric; Klein, Lloyd W; Garratt, Kirk N; Weintraub, William S; Gibson, C Michael

    2014-02-01

    The goal of this study was to compare angiographic interpretation of coronary arteriograms by sites in community practice versus those made by a centralized angiographic core laboratory. The study population consisted of 2013 American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR) records with 2- and 3- vessel coronary disease from 54 sites in 2004 to 2007. The primary analysis compared Registry (NCDR)-defined 2- and 3-vessel disease versus those from an angiographic core laboratory analysis. Vessel-level kappa coefficients suggested moderate agreement between NCDR and core laboratory analysis, ranging from kappa=0.39 (95% confidence intervals, 0.32-0.45) for the left anterior descending artery to kappa=0.59 (95% confidence intervals, 0.55-0.64) for the right coronary artery. Overall, 6.3% (n=127 out of 2013) of those patients identified with multivessel disease at NCDR sites had had 0- or 1-vessel disease by core laboratory reading. There was no directional bias with regard to overcall, that is, 12.3% of cases read as 3-vessel disease by the sites were read as <3-vessel disease by the core laboratory, and 13.9% of core laboratory 3-vessel cases were read as <3-vessel by the sites. For a subset of patients with left main coronary disease, registry overcall was not linked to increased rates of mortality or myocardial infarction. There was only modest agreement between angiographic readings in clinical practice and those from an independent core laboratory. Further study will be needed because the implications for patient management are uncertain.

  1. GDC 360 for the endovascular treatment of intracranial aneurysms: a matched-pair study analysing angiographic outcomes with GDC 3D coils in 38 patients

    International Nuclear Information System (INIS)

    Taschner, Christian A.; Thines, Laurent; Lejeune, Jean-Paul; El-Mahdy, Mohamed; Rachdi, Henda; Gauvrit, Jean-Yves; Pruvo, Jean-Pierre; Leclerc, Xavier

    2009-01-01

    The purpose of this study was to determine whether coil embolisation with a new complex-shaped Guglielmi Detachable Coil (GDC 360 ; Boston Scientific Neurovascular, Fremont, CA, USA) has any effect on the stability of aneurysm occlusion. Fifty-one consecutive patients with intracranial aneurysms treated with GDC 360 were included. Angiographic results and adverse neurological events during the follow-up period were recorded. For 38 patients treated with GDC 360 with available follow-up data, a corresponding patient treated with GDC 3D was identified from our database. Matches were sought for rupture status, location, aneurysmal size, and neck size. The angiographic outcome of these matched controls at 6 months was compared to aneurysms treated with GDC 360 . Initial angiographic controls for 38 patients treated with GDC 360 showed complete occlusion in 32 aneurysms, and a neck remnant in six. At 6-month follow-up, complete occlusion was found in 29, a neck remnant in eight, and a residual aneurysm in one. One patient treated with GDC 360 needed retreatment for a major recanalisation. In 38 matched patients treated with GDC 3D, initial angiographic controls found complete aneurysmal occlusion in 30 aneurysms and a residual neck in 8. At 6-month follow-up, 24 aneurysms were completely occluded, ten showed a neck remnant, and residual aneurysms were seen in four. Four patients, treated with GDC 3D, were retreated for major aneurysm recanalisations. Our data suggests that endovascular coil embolisation with GDC 360 might improve long-term stability of coiled aneurysms when compared to GDC 3D. (orig.)

  2. Gelfond–Bézier curves

    KAUST Repository

    Ait-Haddou, Rachid; Sakane, Yusuke; Nomura, Taishin

    2013-01-01

    We show that the generalized Bernstein bases in Müntz spaces defined by Hirschman and Widder (1949) and extended by Gelfond (1950) can be obtained as pointwise limits of the Chebyshev–Bernstein bases in Müntz spaces with respect to an interval [a,1][a,1] as the positive real number a converges to zero. Such a realization allows for concepts of curve design such as de Casteljau algorithm, blossom, dimension elevation to be transferred from the general theory of Chebyshev blossoms in Müntz spaces to these generalized Bernstein bases that we termed here as Gelfond–Bernstein bases. The advantage of working with Gelfond–Bernstein bases lies in the simplicity of the obtained concepts and algorithms as compared to their Chebyshev–Bernstein bases counterparts.

  3. Bubble Collision in Curved Spacetime

    International Nuclear Information System (INIS)

    Hwang, Dong-il; Lee, Bum-Hoon; Lee, Wonwoo; Yeom, Dong-han

    2014-01-01

    We study vacuum bubble collisions in curved spacetime, in which vacuum bubbles were nucleated in the initial metastable vacuum state by quantum tunneling. The bubbles materialize randomly at different times and then start to grow. It is known that the percolation by true vacuum bubbles is not possible due to the exponential expansion of the space among the bubbles. In this paper, we consider two bubbles of the same size with a preferred axis and assume that two bubbles form very near each other to collide. The two bubbles have the same field value. When the bubbles collide, the collided region oscillates back-and-forth and then the collided region eventually decays and disappears. We discuss radiation and gravitational wave resulting from the collision of two bubbles

  4. Bacterial streamers in curved microchannels

    Science.gov (United States)

    Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

    2009-11-01

    Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.

  5. Gelfond–Bézier curves

    KAUST Repository

    Ait-Haddou, Rachid

    2013-02-01

    We show that the generalized Bernstein bases in Müntz spaces defined by Hirschman and Widder (1949) and extended by Gelfond (1950) can be obtained as pointwise limits of the Chebyshev–Bernstein bases in Müntz spaces with respect to an interval [a,1][a,1] as the positive real number a converges to zero. Such a realization allows for concepts of curve design such as de Casteljau algorithm, blossom, dimension elevation to be transferred from the general theory of Chebyshev blossoms in Müntz spaces to these generalized Bernstein bases that we termed here as Gelfond–Bernstein bases. The advantage of working with Gelfond–Bernstein bases lies in the simplicity of the obtained concepts and algorithms as compared to their Chebyshev–Bernstein bases counterparts.

  6. Micro-angiographic system using synchrotron radiation and conventional x-ray source for visualizing angiogenic vessels induced by cardiovascular regeneration therapy

    International Nuclear Information System (INIS)

    Mori, H.; Chiku, M.; Nishigami, K.; Tanaka, E.; Kimura, K.; Kawai, T.; Suzuki, K.; Mochizuki, R.; Okawa, Y.

    2004-01-01

    Therapeutic angiogenesis improved critical limb and myocardial ischemia in human, however, angiogenic vessels were not visualized well by conventional angiography, because of its limited spatial resolution of 200 μm. Recently, synchrotron radiation system characterized by high brightness, monochromatic and collimated nature revealed the micro-vessels of heart and lower limb in situ. We developed also an in-house microangiographic system with a relatively low cost. Limb ischemia models were made by ligature of femoral artery and treated by angiogenic growth factor genes and so on. One month after the treatment, we evaluated collateral micro-vessels by using the conventional and micro-angiographic systems. The approach was left femoral artery, and catheter was located in abdominal aorta. Iodine contrast (300 mg/ml) was injected 5 ml by 3 ml/sec with auto-injection system. The imaging was recorded by digital source in 1000 x 1000 pixels. The micro-angiographic system could detect the micro-vessels more precisely than conventional angiographic system and evaluate their function. (author)

  7. Correlation of C-Reactive Protein and Cardiac Enzymes with Angiographic Severity of Coronary Artery Disease in Pakistani Patients with Acute Coronary Syndrome.

    Science.gov (United States)

    Saleem, Ayesha; Ali, Azmat

    2017-02-01

    To determine the correlation of C-reactive protein (CRP) levels with the severity of coronary stenosis on angiography and the association of cardiac enzymes with the degree of stenosis in acute coronary syndrome (ACS) patients. Secondly, to compare association of angiographic severity of vascular stenosis with CRP in patients with ST segment elevation myocardial infarction (STEMI) and non-STEMI / Unstable angina (UA). Prospective, descriptive study. Khan Research Laboratories (KRL) Hospital, from October 2014 to March 2015. CRP was measured on diagnosis of ACS in 70 patients. Cardiac enzymes were measured 6 hours after the onset of chest pain. Angiographic scoring for degree of stenosis and number of culprit vessels was done. Two groups consisting of patients with STEMI (group 1) and with NSTEMI/UA (group 2) were made. No correlation was found between CRP levels and angiographic stenosis in patients with ACS (r=0.162, p>0.05). No association was found between eosinophil count and severity of stenosis (p=0.88). Rise of cardiac enzymes and degree of coronary stenosis showed a positive correlation (p Rise in cardiac enzymes still grade high in predicting severity of vascular stenosis than eosinophil count or CRP levels.

  8. Sibling curves of quadratic polynomials | Wiggins | Quaestiones ...

    African Journals Online (AJOL)

    Sibling curves were demonstrated in [1, 2] as a novel way to visualize the zeroes of real valued functions. In [3] it was shown that a polynomial of degree n has n sibling curves. This paper focuses on the algebraic and geometric properites of the sibling curves of real and complex quadratic polynomials. Key words: Quadratic ...

  9. GLOBAL AND STRICT CURVE FITTING METHOD

    NARCIS (Netherlands)

    Nakajima, Y.; Mori, S.

    2004-01-01

    To find a global and smooth curve fitting, cubic B­Spline method and gathering­ line methods are investigated. When segmenting and recognizing a contour curve of character shape, some global method is required. If we want to connect contour curves around a singular point like crossing points,

  10. Trigonometric Characterization of Some Plane Curves

    Indian Academy of Sciences (India)

    IAS Admin

    (Figure 1). A relation between tan θ and tanψ gives the trigonometric equation of the family of curves. In this article, trigonometric equations of some known plane curves are deduced and it is shown that these equations reveal some geometric characteristics of the families of the curves under consideration. In Section 2,.

  11. M-curves and symmetric products

    Indian Academy of Sciences (India)

    Indranil Biswas

    2017-08-03

    Aug 3, 2017 ... is bounded above by g + 1, where g is the genus of X [11]. Curves which have exactly the maximum number (i.e., genus +1) of components of the real part are called M-curves. Classifying real algebraic curves up to homeomorphism is straightforward, however, classifying even planar non-singular real ...

  12. Holomorphic curves in exploded manifolds: Kuranishi structure

    OpenAIRE

    Parker, Brett

    2013-01-01

    This paper constructs a Kuranishi structure for the moduli stack of holomorphic curves in exploded manifolds. To avoid some technicalities of abstract Kuranishi structures, we embed our Kuranishi structure inside a moduli stack of curves. The construction also works for the moduli stack of holomorphic curves in any compact symplectic manifold.

  13. Automated Blazar Light Curves Using Machine Learning

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Spencer James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-07-27

    This presentation describes a problem and methodology pertaining to automated blazar light curves. Namely, optical variability patterns for blazars require the construction of light curves and in order to generate the light curves, data must be filtered before processing to ensure quality.

  14. Angiographically demonstrated coronary collaterals predict residual viable myocardium in patients with chronic myocardial infarction. A regional metabolic study

    International Nuclear Information System (INIS)

    Fukai, Masumi; Ii, Masaaki; Nakakoji, Takahiro

    2000-01-01

    Angiographical demonstration of coronary collateral circulation may suggest the presence of residual viable myocardium. The development of coronary collaterals was judged according to Rentrop's classification in 37 patients with old anteroseptal myocardial infarction and 13 control patients with chest pain syndrome. The subjects with myocardial infarction were divided into 2 groups: 17 patients with the main branch of the left coronary artery clearly identified by collateral blood flow from the contralateral coronary artery [Coll (+) group, male/female 10/7, mean age 56.6 years] and 20 patients with obscure coronary trunk [Coll (-) group, male/female 16/4, mean age 54.9 years]. Thallium-201 myocardial scintigraphy and examination of local myocardial metabolism were carried out by measuring the flux of lactic acid under dipyridamole infusion load. Coronary stenosis of 99% or total occlusion was found in only 5 of 20 patients (25%) in the Coll (-) group but in 16 of 17 patients (94%) in the Coll (+) group (p<0.001). Redistribution of myocardial scintigraphy was found in 11 of 15 patients (73%) in the Coll (+) group, but only 3 of 18 patients (17%) in the Coll (-) group (p<0.01). The myocardial lactic acid extraction rate was -13.2±17.0% in the Coll (+) group, but 9.1±13.2% in the Coll (-) group (p<0.001). These results suggest that coronary collateral may contribute to minimizing the infarct area and to prediction of the presence of viable myocardium. (author)

  15. Clinical and angiographic characteristics of acute myocardial infarction caused by vasospastic angina without organic coronary heart disease

    International Nuclear Information System (INIS)

    Kim, Pum-Joon; Seung, Ki-Bae; Kim, Dong-Bin

    2007-01-01

    Vasospastic angina (VA) can occasionally cause acute myocardial infarction (AMI). From January 2003 to June 2005, coronary spastic angina was diagnosed in 292 patients by performing spasm provocation tests. Among the 292 patients, 21 (7.2% of all the VA patients) had an AMI. There were 20 patients who initially visited the emergency room for AMI without suffering prior VA. One patient with a history of VA had an AMI when he discontinued his medication. Among the 21 VA patients with AMI, 14 had experienced severe emotional stress before they visited the emergency room. The spasm provocation test showed that the VA patients with AMI had more multivessel and diffuse spasm than the VA patients without AMI (p<0.001). Clinically, the VA patients with AMI usually had their first symptom of VA as the severe chest pain of AMI. Two-thirds of the VA patients with AMI had experienced emotional stress before their AMI. Angiographically, the spasm provocation test for VA patients with AMI showed more multivessel and diffuse spasm than in VA patients without AMI. (author)

  16. CT and angiographic analysis of posterior communicating artery aneurysms: What factors influence the amount of subarachnoid blood?

    International Nuclear Information System (INIS)

    Kim, Young Min; Jung, Kun Sik; Rho, Myung Ho; Choi, Pil Youb; Sung, Young Soon; Kwon, Jae Soo; Lee, Sang Wook

    1998-01-01

    To determine how clinical and angiographic factors relate to the amount of subarachnoid blood detected by computerized tomography in patients with a ruptured aneurysm. Between January 1996 and December 1997, 22 patients with a posterior communicating artery aneurysm were retrospectively evaluated. Oval(three of four cases), funnel(both cases), and daughter-sac (four of five cases) types of aneurysmal sac were found among the 13 patients with a large amount of subarachnoid blood;eight of these had a past history of hyertension or diabetes. Seven of eleven cases of cylindricaltype aneurysmal sac were found among the 9 patients with a small amount of sularachnoid blood;eight of these had no past history of hypertension or diabetes. The average S/N ratio (ratio of maximum sac length to neck diameter) of patients with a small amount of blood was higher than that of patients with a large amount of blood(2.72 vs 2.07). Although many factors influence the amount of subarachnoid blood in an aneurysmal rupture, we found that a large amount of blood was frequently present in the oval, funnel and daughter sac types of aneurysm, when S/N ratio was low, and when an underlying disease such as hypertension or diabetes was present. Conversely, a small amount of blood was present in the cylindrical type, when S/N ratio was high, and where there was no underlying disease.=20

  17. Blunt renal trauma: comparison of contrast-enhanced CT and angiographic findings and the usefulness of transcatheter arterial embolization

    International Nuclear Information System (INIS)

    Kitase, M.; Mizutani, M.; Tomita, H.; Kono, T.; Sugie, C.; Shibamoto, Y.

    2007-01-01

    Full text: Background: The purpose of this study was to evaluate the role of contrast-enhanced CT and the usefulness of super selective embolization therapy in the management of arterial damage in patients with severe blunt renal trauma. Patients and Methods: Nine cases of severe renal trauma were evaluated. In all cases, we compared contrast enhanced CT findings with angiographic findings, and performed transcatheter arterial embolization (TAE) in six of them with microcoils and gelatin sponge particles. Morphological changes in the kidney and site of infarction after TAE were evaluated on follow-up CT Chronological changes in blood biochemistry findings after injury, degree of anemia and renal function were investigated. Adverse effects or complications such as duration of hematuria, fever, abdominal pain, renovascular hypertension and abscess formation were also evaluated. Results: The CT finding of extravasation was a reliable sign of active bleeding and useful for determining the indication of TAE. In all cases, bleeding was effectively controlled with super selective embolization. There was minimal procedure-related loss of renal tissue. None of the patients developed abscess, hypertension or other complications. Conclusions: In blunt renal injury, contrast-enhanced CT was useful for diagnosing arterial hemorrhage. Arterial bleeding may produce massive hematoma and TAE was a useful treatment for such cases. By using selective TAE for a bleeding artery, it was possible to minimize renal parenchymal damage, with complications of TAE rarely seen. (author)

  18. Quantitative angiographic anatomy of the renal arteries and adjacent aorta in the swine for preclinical studies of intravascular catheterization devices.

    Science.gov (United States)

    Sakaoka, Atsushi; Koshimizu, Masafumi; Nakamura, Shintaro; Matsumura, Kiyoshi

    2018-05-10

    Swine are the most common animal model in preclinical studies of cardiovascular devices. Because of the recent trend for development of new devices for percutaneous catheterization, especially for the renal arteries (RAs), we examined the quantitative anatomical dimensions of the RAs and adjacent aorta in swine. Angiographic images were analyzed in 66 female Yorkshire/Landrace crossbred swine. The diameter of both the right and left main RA was 5.4 ± 0.6 mm. The length of the right main RA was significantly longer than that of the left (29.8 ± 7.5 mm vs. 20.6 ± 5.4 mm, respectively; Pswine are an appropriate animal model for assessing the safety of, and determining optimal design of, catheter devices for RAs in simulated clinical use. However, there were species differences in the branching angle and adjacent aorta diameter, suggesting that swine models alone are inadequate to assess the delivery performance of catheter devices for RAs.

  19. Zinc and copper levels are not correlated with angiographically-defined coronary artery disease in sudanese patients.

    Science.gov (United States)

    Lutfi, Mohamed F; Elhakeem, Ramaze F; Khogaly, Raga S; Abdrabo, Abdelkarim A; Ali, Ahmed B; Gasim, Gasim I; Adam, Ishag

    2015-01-01

    We investigated zinc and copper levels in angiographically defined obstructive coronary artery disease (CAD) in patients undergoing elective coronary angiography in El-Shaab Hospital, Sudan. We performed a cross-sectional study. One hundred forty-two patients were enrolled. Sociodemographic and medical characteristics were collected using a questionnaire. Glucose, lipid, zinc, and copper levels were measured. Out of 142 patients, 102 (71.8%) had CAD and 40 (28.2%) had patent coronary arteries. There were no significant differences in median (interquartile range) zinc [118.5 (97.2-151.0) vs. 130.0 (106.0-174.0) μg/ml, P = 0.120] and copper [150.6 (125.0-183.0) vs. 158 (132.0-180.0) μg/mL, P = 0.478] levels between patients with CAD and those with patent coronary arteries. In linear regression analysis, there were no associations between CAD and zinc and copper levels. The current study failed to show any significant association between CAD and zinc and copper levels.

  20. Validation of attenuation-corrected equilibrium radionuclide angiographic determinations of right ventricular volume: comparison with cast-validated biplane cineventriculography

    International Nuclear Information System (INIS)

    Dell'Italia, L.J.; Starling, M.R.; Walsh, R.A.; Badke, F.R.; Lasher, J.C.; Blumhardt, R.

    1985-01-01

    To determine the accuracy of attenuation-corrected equilibrium radionuclide angiographic determinations of right ventricular volumes, the authors initially studied 14 postmortem human right ventricular casts by water displacement and biplane cineventriculography. Biplane cineventriculographic right ventricular cast volumes, calculated by a modification of Simpson's rule algorithm, correlated well with right ventricular cast volumes measured by water displacement (r = .97, y = 8 + 0.88x, SEE = 6 ml). Moreover, the mean volumes obtained by both methods were no different (73 +/- 28 vs 73 +/- 25 ml). Subsequently, they studied 16 patients by both biplane cineventriculography and equilibrium radionuclide angiography. The uncorrected radionuclide right ventricular volumes were calculated by normalizing background corrected end-diastolic and end-systolic counts from hand-drawn regions of interest obtained by phase analysis for cardiac cycles processed, frame rate, and blood sample counts. Attenuation correction was performed by a simple geometric method. The attenuation-corrected radionuclide right ventricular end-diastolic volumes correlated with the cineventriculographic end-diastolic volumes (r = .91, y = 3 + 0.92x, SEE = 27 ml). Similarly, the attenuation-corrected radionuclide right ventricular end-systolic volumes correlated with the cineventriculographic end-systolic volumes (r = .93, y = - 1 + 0.91x, SEE = 16 ml). Also, the mean attenuation-corrected radionuclide end-diastolic and end-systolic volumes were no different than the average cineventriculographic end-diastolic and end-systolic volumes (160 +/- 61 and 83 +/- 44 vs 170 +/- 61 and 86 +/- 43 ml, respectively)

  1. Vascular changes in sporadic ergotism. Epidemiology, pathogenesis, clinical practice, and diagnosis with special regard to angiographic documentation

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, B.

    1986-08-01

    Whereas the epidemic form of ergotism has been rare in the 20th century, the sporadic form has a wide distribution as a consequence of therapy with ergot-derivative drugs. Favourable prognosis of the condition, with complete recovery from the ischemic peripheral circulatory disorders can be obtained by early diagnosis. Precise evaluation of the history, with recognition of treatment of migraine headache or postpartum hemorraghe with ergot alkaloids, can be determinative in diagnosis. The specific pattern of the angiographic findings, as we saw it in 6 cases within the last 4 years, decisively confirms the diagnosis. We could demonstrate thread-, thorn- and hour glass-like narrowing of the vessels, due to spasm. Total occlusion with the development of collaterals may occur, but we saw no thrombus formation. The stenotic arterial segments had smooth margins. The distribution of the involved arteries was more focal than generalized and more peripheral than central. In two cases spasm could be abolished immediately by a pharmaceutical (i.a. injection of tolazoline) or by anesthetic procedures (halothane). The phenomenologic data, together with the complete reversal of the circulatory ischemic disorders after therapy (particularly the absolute ban of ergots), is so specific that other diseases of ischemic nature (emboli, arteriosclerosis, Buerger's disease, fibromuscular hyperplasia) can be excluded.

  2. Stent underexpansion in angiographic guided percutaneous coronary intervention, despite adjunctive balloon post-dilatation, in drug eluting stent era

    Directory of Open Access Journals (Sweden)

    Mehrdad Taherioun

    2014-01-01

    Full Text Available BACKGROUND: Stent underexpansion is the most powerful predictor of long-term stent patency and clinical outcome. The purpose of this study was to evaluate the incidence and predictors of stent underexpansion despite adjunctive post-dilatation with non-compliant balloon. METHODS: After elective coronary stent implantation and adjunctive post-dilatation with non-compliant balloon and optimal angiographic result confirmed by the operator, intravascular ultrasound (IVUS was performed for all the treated lesions. If the treated lesions fulfilled the IVUS criteria, they are considered as the optimal stent group; if not, they are considered as the suboptimal group. RESULTS: From 50 patients enrolled in this study 39 (78% had optimal stent deployment and 11 (22% had suboptimal stent deployment. In the suboptimal group 7 (14% had underexpansion, 2 (4% malposition, and 2 (4% had asymmetry. There were no stent edge dissections detected by IVUS. We did not find any correlation between lesion calcification, ostial lesions, stent length, and stent underexpansion. Stent diameter ≤ 2.75 mm had a strong correlation with stent underexpansion. CONCLUSION: Despite adjunctive post-dilatation with noncompliant balloon, using a relatively small stent diameter was a strong predictor for underexpansion. IVUS guided percutaneous coronary intervention (PCI may be considered for drug eluting stent (DES implantation in relatively small vessels.   Keywords: Stent, Percutaneous Coronary Intervention, Ultrasound, Post-dilatation 

  3. Radionuclide angiographic evaluation of left ventricular performance at rest and during exercise in patients with aortic regurgitation

    International Nuclear Information System (INIS)

    Iskandrian, A.S.; Heo, J.

    1986-01-01

    Radionuclide angiographic evaluation of LV performance at rest and during exercise in patients with AR have shown that an abnormal EF response to exercise may be observed in asymptomatic patients with normal resting LV function. The EF response to exercise has been correlated with a number of clinical and exercise measurements; important among these are the slope of the systolic pressure-to-end-systolic volume, end-systolic volume, cardiac index, pulmonary capillary wedge pressure, and wall stress. The changes in the regurgitant fraction, EF, and LV volume have shown considerable individual variability; they have also allowed a better understanding of the circulatory responses during exercise. Radionuclide angiography provides a reliable and reproducible method of measuring the rest LVEF that is important in the timing and the outcome of valve replacement. The value of the EF response to exercise in patient management is not yet clear; it is possible that other radionuclide-derived measurements at rest or during exercise, such as the systolic pressure-to-end-systolic volume relationship, and the end-systolic volume may provide complementary information to that provided by the EF

  4. Angiographic and hemodynamic evaluation of the mesoatrial shunt in patients with Budd-Chiari syndrome and inferior vena caval obstruction

    International Nuclear Information System (INIS)

    Redmond, P.L.; Kadir, S.; Cameron, J.L.; Kaufman, S.L.; White, R.I. Jr.

    1986-01-01

    Obstruction of the inferior vena cava (IVC) is not uncommon in patients with the Budd-Chiari syndrome. The caval obstruction may be due to thrombus or compression by an enlarged caudate lobe. Conventional portosystemic shunts are not possible in the presence of an obstructed IVC; the mesoatrial shunt is indicated in these patients. Between 1973 and 1986, the authors studied 13 patients (ten female, three male) with Budd-Chiari syndrome and IVC obstruction in whom mesoatrial shunts were subsequently constructed. Polycythemia rubra vera was the most common predisposing condition. Preoperative evaluation included US, scintigraphy, CT, and angiography (hepatic arteriography, hepatic venography and pressure measurements, inferior vena cavography, arterial portography). Postoperatively shunts were assessed angiographically and hemodynamically, and several patients underwent CT. The shunts were catheterized via a brachial or femoral venous approach, which allowed pressures along the shunt from the superior mesenteric vein to the right atrium to be measured. The mesoatrial shunt is a relatively new procedure which is indicated in patients with the Budd-Chiari syndrome complicated by IVC obstruction. Shunt patency may be demonstrated arteriographically or with CT, but hemodynamic evaluation with measurement of pressure gradients is required to assess shunt function

  5. Correlation between intrasac pressure measurements of a pressure sensor and an angiographic catheter during endovascular repair of abdominal aortic aneurysm

    Directory of Open Access Journals (Sweden)

    Pierre Galvagni Silveira

    2008-01-01

    Full Text Available PURPOSE: To establish a correlation between intrasac pressure measurements of a pressure sensor and an angiographic catheter placed in the same aneurysm sac before and after its exclusion by an endoprosthesis. METHODS: Patients who underwent endovascular abdominal aortic aneurysm repair and received an EndoSureTM wireless pressure sensor implant between March 19 and December 11, 2004 were enrolled in the study. Simultaneous readings of systolic, diastolic, mean, and pulse pressure within the aneurysm sac were obtained from the catheter and the sensor, both before and after sac exclusion by the endoprosthesis (Readings 1 and 2, respectively. Intrasac pressure measurements were compared using Pearson's correlation and Student's t test. Statistical significance was set at p0.05, mean (p>0.05, and pulse (p0.05 by the sensor. CONCLUSION: The excellent agreement between intrasac pressure readings recorded by the catheter and the sensor justifies use of the latter for detection of post-exclusion abdominal aortic aneurysm pressurization.

  6. Advanced 2-dimensional quantitative coronary angiographic analysis for prediction of fractional flow reserve in intermediate coronary stenoses.

    Science.gov (United States)

    Opolski, Maksymilian P; Pregowski, Jerzy; Kruk, Mariusz; Kepka, Cezary; Staruch, Adam D; Witkowski, Adam

    2014-07-01

    The widespread clinical application of coronary computed tomography angiography (CCTA) has resulted in increased referral patterns of patients with intermediate coronary stenoses to invasive coronary angiography. We evaluated the application of advanced quantitative coronary angiography (A-QCA) for predicting fractional flow reserve (FFR) in intermediate coronary lesions detected on CCTA. Fifty-six patients with 66 single intermediate coronary lesions (≥ 50% to 80% stenosis) on CCTA prospectively underwent coronary angiography and FFR. A-QCA including calculation of the Poiseuille-based index defined as the ratio of lesion length to the fourth power of the minimal lumen diameter (MLD) was performed. Significant stenosis was defined as FFR ≤ 0.80. The mean FFR was 0.86 ± 0.09, and 18 lesions (27%) were functionally significant. FFR correlated with lesion length (R=-0.303, P=0.013), MLD (R=0.527, P44%, and >69%, respectively (maximum negative predictive value of 94% for MLA, maximum positive predictive value of 58% for diameter stenosis). The Poiseuille-based index was the most accurate (C statistic 0.86, sensitivity 100%, specificity 71%, positive predictive value 56%, and negative predictive value 100%) predictor of FFR ≤ 0.80, but showed the lowest interobserver agreement (intraclass correlation coefficient 0.37). A-QCA might be used to rule out significant ischemia in intermediate stenoses detected by CCTA. The diagnostic application of the Poiseuille-based angiographic index is precluded by its high interobserver variability.

  7. A preliminary discussion of angiographic anatomy and variations of rabbit hepatic vessels and catheterization methods of hepatic artery

    International Nuclear Information System (INIS)

    Wang Diaodong; Yang Renjie; Zhang Hongzhi; Sun Hongliang

    2006-01-01

    Objective: To study the normal angiographic anatomy and variations of rabbit hepatic vessels, and explore the optimal method for hepatic artery catheterization. Methods: 30 rabbits were divided into two groups randomly. Modified surgical method and interventional method were used to catheterize hepatic artery respectively, and followed by angiography to demonstrate the normal anatomy and variations of rabbit celiac artery, hepatic artery and portal vein. Results: The route and distribution of rabbit celiac artery and hepatic artery were very different from human's. The commonly seen variation showed the differences in branching bifurcation of hepatic-gastric artery, with the incidence of 13.3%. The rates of successfully hepatic artery catheterization with surgical and interventional methods were 86.6%(13/15) and 80%(12/15) respectively (P>0.05). The surgical method will not be successful, whenever there's variation. Conclusion: The normal anatomy and variation of rabbit celiac artery and hepatic artery are quite different from human's. Both surgical and interventional catheterizations could be rather successful but possessing advantages and disadvantages of each its own. (authors)

  8. The effects of tirofiban infusion on clinical and angiographic outcomes of patients with STEMI undergoing primary PCI.

    Science.gov (United States)

    Kaymaz, Cihangir; Keleş, Nurşen; Özdemir, Nihal; Tanboğa, İbrahim Halil; Demircan, Hacer C; Can, Mehmet M; Koca, Fatih; İzgi, İbrahim Akın; Özkan, Alper; Türkmen, Muhsin; Kırma, Cevat; Esen, Ali M

    2015-11-01

    The present study was designed to determine the effects of tirofiban (Tiro) infusion on angiographic measures, ST-segment resolution, and clinical outcomes in patients with STEMI undergoing PCI. Glycoprotein (GP) IIb/IIIa inhibitors are beneficial in ST-segment elevation myocardial infarction (STEMI) patients undergoing percutaneous coronary intervention (PCI), while the most effective timing of administration is still under investigation. A total of 1242 patients (83.0% males, mean (standard deviation; SD) age: 54.7 (10.9) years) with STEMI who underwent primary PCI were included in this retrospective non-randomized study in four groups, composed of no tirofiban infusion [Tiro (-); n=248], tirofiban infusion before PCI (pre-Tiro; n=720), tirofiban infusion during PCI (peri-Tiro; n=50), and tirofiban infusion after PCI (post-Tiro; n=224). In all Tiro (+) patients, bolus administration of Tiro (10 µg/kg) was followed by infusion (0.15 µg/kg/min) for a mean (SD) duration of 22.4±6.8 hours. The pre-PCI Tiro group was associated with the highest percentage of patients with TIMI 3 flow (99.4%; p75% ST-segment resolution (78.1%; pPCI significantly improves myocardial reperfusion, ST-segment resolution, in-hospital mortality rate, and in-hospital sudden cardiac death in patients with STEMI with no increased risk of major bleeding.

  9. Angiographic Cystoid Macular Edema and Outcomes in the Comparison of Age-Related Macular Degeneration Treatments Trials.

    Science.gov (United States)

    Shah, Neepa; Maguire, Maureen G; Martin, Daniel F; Shaffer, James; Ying, Gui-Shuang; Grunwald, Juan E; Toth, Cynthia A; Jaffe, Glenn J; Daniel, Ebenezer

    2016-04-01

    To describe morphologic and visual outcomes in eyes with angiographic cystoid macular edema (CME) treated with ranibizumab or bevacizumab for neovascular age-related macular degeneration (nAMD). Prospective cohort study within a randomized clinical trial. A total of 1185 CATT study subjects. Baseline fluorescein angiography (FA) images of all CATT study eyes were evaluated for CME. Grading of other characteristics on optical coherence tomography (OCT) and photographic images at baseline and during 2-year follow-up was completed by readers at the CATT Reading Centers. Three groups were created on the basis of baseline CME and intraretinal fluid (IRF) status: (1) CME, (2) IRF without CME, (3) neither CME nor IRF. Visual acuity (VA) and total central retinal thickness (CRT) on OCT at baseline, year 1, and year 2. Among 1131 participants with images of sufficient quality for determining CME and IRF at baseline, 92 (8.1%) had CME, 766 (67.7%) had IRF without CME, and 273 (24.1%) had neither. At baseline, eyes with CME had worse mean VA (letters) than eyes with IRF without CME and eyes with neither CME nor IRF (52 vs. 60 vs. 66 letters, P macular edema seems to be a marker for poorer visual outcomes in nAMD because of underlying baseline retinal dysfunction and subsequent scarring. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  10. Method of construction spatial transition curve

    Directory of Open Access Journals (Sweden)

    S.V. Didanov

    2013-04-01

    Full Text Available Purpose. The movement of rail transport (speed rolling stock, traffic safety, etc. is largely dependent on the quality of the track. In this case, a special role is the transition curve, which ensures smooth insertion of the transition from linear to circular section of road. The article deals with modeling of spatial transition curve based on the parabolic distribution of the curvature and torsion. This is a continuation of research conducted by the authors regarding the spatial modeling of curved contours. Methodology. Construction of the spatial transition curve is numerical methods for solving nonlinear integral equations, where the initial data are taken coordinate the starting and ending points of the curve of the future, and the inclination of the tangent and the deviation of the curve from the tangent plane at these points. System solutions for the numerical method are the partial derivatives of the equations of the unknown parameters of the law of change of torsion and length of the transition curve. Findings. The parametric equations of the spatial transition curve are calculated by finding the unknown coefficients of the parabolic distribution of the curvature and torsion, as well as the spatial length of the transition curve. Originality. A method for constructing the spatial transition curve is devised, and based on this software geometric modeling spatial transition curves of railway track with specified deviations of the curve from the tangent plane. Practical value. The resulting curve can be applied in any sector of the economy, where it is necessary to ensure a smooth transition from linear to circular section of the curved space bypass. An example is the transition curve in the construction of the railway line, road, pipe, profile, flat section of the working blades of the turbine and compressor, the ship, plane, car, etc.

  11. Power forward curves: a managerial perspective

    International Nuclear Information System (INIS)

    Nagarajan, Shankar

    1999-01-01

    This chapter concentrates on managerial application of power forward curves, and examines the determinants of electricity prices such as transmission constraints, its inability to be stored in a conventional way, its seasonality and weather dependence, the generation stack, and the swing risk. The electricity forward curve, classical arbitrage, constructing a forward curve, volatilities, and electricity forward curve models such as the jump-diffusion model, the mean-reverting heteroscedastic volatility model, and an econometric model of forward prices are examined. A managerial perspective of the applications of the forward curve is presented covering plant valuation, capital budgeting, performance measurement, product pricing and structuring, asset optimisation, valuation of transmission options, and risk management

  12. Retrograde curves of solidus and solubility

    International Nuclear Information System (INIS)

    Vasil'ev, M.V.

    1979-01-01

    The investigation was concerned with the constitutional diagrams of the eutectic type with ''retrograde solidus'' and ''retrograde solubility curve'' which must be considered as diagrams with degenerate monotectic transformation. The solidus and the solubility curves form a retrograde curve with a common retrograde point representing the solubility maximum. The two branches of the Aetrograde curve can be described with the aid of two similar equations. Presented are corresponding equations for the Cd-Zn system and shown is the possibility of predicting the run of the solubility curve

  13. The writhe of open and closed curves

    International Nuclear Information System (INIS)

    Berger, Mitchell A; Prior, Chris

    2006-01-01

    Twist and writhe measure basic geometric properties of a ribbon or tube. While these measures have applications in molecular biology, materials science, fluid mechanics and astrophysics, they are under-utilized because they are often considered difficult to compute. In addition, many applications involve curves with endpoints (open curves); but for these curves the definition of writhe can be ambiguous. This paper provides simple expressions for the writhe of closed curves, and provides a new definition of writhe for open curves. The open curve definition is especially appropriate when the curve is anchored at endpoints on a plane or stretches between two parallel planes. This definition can be especially useful for magnetic flux tubes in the solar atmosphere, and for isotropic rods with ends fixed to a plane

  14. WE-E-18A-10: Comparison of Patient Dose and Vessel Visibility Between Antiscatter Grid Removal and Lower Angiographic Radiation Dose Settings for Pediatric Imaging: A Preclinical Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, K; Nachabe, R; Racadio, J [Children' s Hospital Medical Center, Cincinnati, OH (United States)

    2014-06-15

    Purpose: To define an alternative to antiscatter grid (ASG) removal in angiographic systems which achieves similar patient dose reduction as ASG removal without degrading image quality during pediatric imaging. Methods: This study was approved by the local institution animal care and use committee (IACUC). Six different digital subtraction angiography settings were evaluated that altered the mAs, (100, 70, 50, 35, 25, 17.5% of reference mAs) with and without ASG. Three pigs of 5, 15, and 20 kg (9, 15, and 17 cm abdominal thickness; smaller than a newborn, average 3 yr old, and average 10 year old human abdomen respectively) were imaged using the six dose settings with and without ASG. Image quality was defined as the order of vessel branch that is visible relative to the injected vessel. Five interventional radiologists evaluated all images. Image quality and patient dose were statistically compared using analysis of variance and receiver operating curve (ROC) analysis to define the preferred dose level and use of ASG for a minimum visibility of 2nd or 3rd order branches of vessel visibility. Results: ASG grid removal reduces dose by 26% with reduced image quality. Only with the ASG present can 3rd order branches be visualized; 100% mAs is required for 9 cm pig while 70% mAs is adequate for the larger pigs. 2nd order branches can be visualized with ASG at 17.5% mAs for all three pig sizes. Without the ASG, 50%, 35% and 35% mAs is required for smallest to largest pig. Conclusion: Removing ASG reduces patient dose and image quality. Image quality can be improved with the ASG present while further reducing patient dose if an optimized radiographic technique is used. Rami Nachabe is an employee of Philips Health Care; Keith Strauss is a paid consultant of Philips Health Care.

  15. Path integrals on curved manifolds

    International Nuclear Information System (INIS)

    Grosche, C.; Steiner, F.

    1987-01-01

    A general framework for treating path integrals on curved manifolds is presented. We also show how to perform general coordinate and space-time transformations in path integrals. The main result is that one has to subtract a quantum correction ΔV ∝ ℎ 2 from the classical Lagrangian L, i.e. the correct effective Lagrangian to be used in the path integral is L eff = L-ΔV. A general prescription for calculating the quantum correction ΔV is given. It is based on a canonical approach using Weyl-ordering and the Hamiltonian path integral defined by the midpoint prescription. The general framework is illustrated by several examples: The d-dimensional rotator, i.e. the motion on the sphere S d-1 , the path integral in d-dimensional polar coordinates, the exact treatment of the hydrogen atom in R 2 and R 3 by performing a Kustaanheimo-Stiefel transformation, the Langer transformation and the path integral for the Morse potential. (orig.)

  16. Page curves for tripartite systems

    International Nuclear Information System (INIS)

    Hwang, Junha; Lee, Deok Sang; Nho, Dongju; Oh, Jeonghun; Park, Hyosub; Zoe, Heeseung; Yeom, Dong-han

    2017-01-01

    We investigate information flow and Page curves for tripartite systems. We prepare a tripartite system (say, A , B , and C ) of a given number of states and calculate information and entropy contents by assuming random states. Initially, every particle was in A (this means a black hole), and as time goes on, particles move to either B (this means Hawking radiation) or C (this means a broadly defined remnant, including a non-local transport of information, the last burst, an interior large volume, or a bubble universe, etc). If the final number of states of the remnant is smaller than that of Hawking radiation, then information will be stored by both the radiation and the mutual information between the radiation and the remnant, while the remnant itself does not contain information. On the other hand, if the final number of states of the remnant is greater than that of Hawking radiation, then the radiation contains negligible information, while the remnant and the mutual information between the radiation and the remnant contain information. Unless the number of states of the remnant is large enough compared to the entropy of the black hole, Hawking radiation must contain information; and we meet the menace of black hole complementarity again. Therefore, this contrasts the tension between various assumptions and candidates of the resolution of the information loss problem. (paper)

  17. Vacuum polarization in curved spacetime

    International Nuclear Information System (INIS)

    Guy, R.W.

    1979-01-01

    A necessary step in the process of understanding the quantum theory of gravity is the calculation of the stress-energy tensor of quantized fields in curved space-times. The determination of the stress tensor, a formally divergent object, is made possible in this dissertation by utilizing the zeta-function method of regularization and renormalization. By employing this scheme's representation of the renormalized effective action functional, an expression of the stress tensor for a massless, conformally invariant scalar field, first given by DeWitt, is derived. The form of the renormalized stress tensor is first tested in various examples of flat space-times. It is shown to vanish in Minkowski space and to yield the accepted value of the energy density in the Casimir effect. Next, the stress tensor is calculated in two space-times of constant curvature, the Einstein universe and the deSitter universe, and the results are shown to agree with those given by an expression of the stress tensor that is valid in conformally flat space-times. This work culminates in the determination of the stress tensor on the horizon of a Schwarzschild black hole. This is accomplished by approximating the radial part of the eigen-functions and the metric in the vicinity of the horizon. The stress tensor at this level approximation is found to be pure trace. The approximated forms of the Schwarzschild metric describes a conformally flat space-time that possesses horizons

  18. Avaliação da autofluorescência do fundo de olho nas distrofias de retina com o aparelho Heidelberg Retina Angiograph2 Evaluation of fundus autofluorescence in hereditary retinal diseases using Heidelberg Retina Angiograph2

    Directory of Open Access Journals (Sweden)

    Monique Côco

    2007-10-01

    Full Text Available OBJETIVOS: Definir características do exame de autofluorescência, verificando sua utilidade no diagnóstico e acompanhamento de distrofias retinianas. MÉTODOS: Participaram do estudo, 28 pacientes, adultos, divididos igualmente em quatro grupos com diagnósticos de doença de Stargardt, distrofia de Cones, retinose pigmentar e voluntários saudáveis para estabelecimento do padrão de normalidade. Em média foram obtidas nove imagens com o filtro para angiofluoresceinografia para a formação da imagem autofluorescente no Heidelberg Retina Angiograph2. As imagens de cada grupo de pacientes foram analisadas para verificar características comuns. RESULTADOS: As imagens fundoscópicas autofluorescentes dos voluntários do grupo controle mostraram área foveal hipoautofluorescente em relação à retina do pólo posterior. As imagens dos portadores de doença de Stargardt, em geral, apresentaram lesão hipoautofluorescente, correspondendo à área macular. As principais alterações da autofluorescência em pacientes com distrofia de cones foram hipoautofluorescência macular com halo hiperautofluorescente. Nos portadores de retinose pigmentar, foram encontrados pigmentos periféricos causando hipoautofluorescência. Na região macular, hipoautofluorescência ou apenas desorganização do pigmento. CONCLUSÃO: O estudo mostrou a existência de padrões de autofluorescência de fundo nas distrofias de retina que permitem o diagnóstico e melhor interpretação da fisiopatogenia destas doenças.PURPOSE: To define characteristics of the fundus autofluorescence examination, verifying usefulness in the diagnosis and care of hereditary retinal diseases. METHODS: 28 patients, adults, divided equally into four groups with diagnoses of Stargardt macular dystrophy, cone dystrophy, retinitis pigmentosa and healthy volunteers for the establishment of the normality pattern. An average of nine images with the filter for fluorescein angiography was obtained

  19. Consistent Valuation across Curves Using Pricing Kernels

    Directory of Open Access Journals (Sweden)

    Andrea Macrina

    2018-03-01

    Full Text Available The general problem of asset pricing when the discount rate differs from the rate at which an asset’s cash flows accrue is considered. A pricing kernel framework is used to model an economy that is segmented into distinct markets, each identified by a yield curve having its own market, credit and liquidity risk characteristics. The proposed framework precludes arbitrage within each market, while the definition of a curve-conversion factor process links all markets in a consistent arbitrage-free manner. A pricing formula is then derived, referred to as the across-curve pricing formula, which enables consistent valuation and hedging of financial instruments across curves (and markets. As a natural application, a consistent multi-curve framework is formulated for emerging and developed inter-bank swap markets, which highlights an important dual feature of the curve-conversion factor process. Given this multi-curve framework, existing multi-curve approaches based on HJM and rational pricing kernel models are recovered, reviewed and generalised and single-curve models extended. In another application, inflation-linked, currency-based and fixed-income hybrid securities are shown to be consistently valued using the across-curve valuation method.

  20. Evaluation of interpolation methods for surface-based motion compensated tomographic reconstruction for cardiac angiographic C-arm data

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Kerstin; Schwemmer, Chris; Hornegger, Joachim [Pattern Recognition Lab, Department of Computer Science, Erlangen Graduate School in Advanced Optical Technologies (SAOT), Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen 91058 (Germany); Zheng Yefeng; Wang Yang [Imaging and Computer Vision, Siemens Corporate Research, Princeton, New Jersey 08540 (United States); Lauritsch, Guenter; Rohkohl, Christopher; Maier, Andreas K. [Siemens AG, Healthcare Sector, Forchheim 91301 (Germany); Schultz, Carl [Thoraxcenter, Erasmus MC, Rotterdam 3000 (Netherlands); Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States)

    2013-03-15

    Purpose: For interventional cardiac procedures, anatomical and functional information about the cardiac chambers is of major interest. With the technology of angiographic C-arm systems it is possible to reconstruct intraprocedural three-dimensional (3D) images from 2D rotational angiographic projection data (C-arm CT). However, 3D reconstruction of a dynamic object is a fundamental problem in C-arm CT reconstruction. The 2D projections are acquired over a scan time of several seconds, thus the projection data show different states of the heart. A standard FDK reconstruction algorithm would use all acquired data for a filtered backprojection and result in a motion-blurred image. In this approach, a motion compensated reconstruction algorithm requiring knowledge of the 3D heart motion is used. The motion is estimated from a previously presented 3D dynamic surface model. This dynamic surface model results in a sparse motion vector field (MVF) defined at control points. In order to perform a motion compensated reconstruction, a dense motion vector field is required. The dense MVF is generated by interpolation of the sparse MVF. Therefore, the influence of different motion interpolation methods on the reconstructed image quality is evaluated. Methods: Four different interpolation methods, thin-plate splines (TPS), Shepard's method, a smoothed weighting function, and a simple averaging, were evaluated. The reconstruction quality was measured on phantom data, a porcine model as well as on in vivo clinical data sets. As a quality index, the 2D overlap of the forward projected motion compensated reconstructed ventricle and the segmented 2D ventricle blood pool was quantitatively measured with the Dice similarity coefficient and the mean deviation between extracted ventricle contours. For the phantom data set, the normalized root mean square error (nRMSE) and the universal quality index (UQI) were also evaluated in 3D image space. Results: The quantitative evaluation of

  1. Evaluation of interpolation methods for surface-based motion compensated tomographic reconstruction for cardiac angiographic C-arm data

    International Nuclear Information System (INIS)

    Müller, Kerstin; Schwemmer, Chris; Hornegger, Joachim; Zheng Yefeng; Wang Yang; Lauritsch, Günter; Rohkohl, Christopher; Maier, Andreas K.; Schultz, Carl; Fahrig, Rebecca

    2013-01-01

    Purpose: For interventional cardiac procedures, anatomical and functional information about the cardiac chambers is of major interest. With the technology of angiographic C-arm systems it is possible to reconstruct intraprocedural three-dimensional (3D) images from 2D rotational angiographic projection data (C-arm CT). However, 3D reconstruction of a dynamic object is a fundamental problem in C-arm CT reconstruction. The 2D projections are acquired over a scan time of several seconds, thus the projection data show different states of the heart. A standard FDK reconstruction algorithm would use all acquired data for a filtered backprojection and result in a motion-blurred image. In this approach, a motion compensated reconstruction algorithm requiring knowledge of the 3D heart motion is used. The motion is estimated from a previously presented 3D dynamic surface model. This dynamic surface model results in a sparse motion vector field (MVF) defined at control points. In order to perform a motion compensated reconstruction, a dense motion vector field is required. The dense MVF is generated by interpolation of the sparse MVF. Therefore, the influence of different motion interpolation methods on the reconstructed image quality is evaluated. Methods: Four different interpolation methods, thin-plate splines (TPS), Shepard's method, a smoothed weighting function, and a simple averaging, were evaluated. The reconstruction quality was measured on phantom data, a porcine model as well as on in vivo clinical data sets. As a quality index, the 2D overlap of the forward projected motion compensated reconstructed ventricle and the segmented 2D ventricle blood pool was quantitatively measured with the Dice similarity coefficient and the mean deviation between extracted ventricle contours. For the phantom data set, the normalized root mean square error (nRMSE) and the universal quality index (UQI) were also evaluated in 3D image space. Results: The quantitative evaluation of all

  2. Construction of calibration curve for accountancy tank

    International Nuclear Information System (INIS)

    Kato, Takayuki; Goto, Yoshiki; Nidaira, Kazuo

    2009-01-01

    Tanks are equipped in a reprocessing plant for accounting solution of nuclear material. The careful measurement of volume in tanks is very important to implement rigorous accounting of nuclear material. The calibration curve relating the volume and level of solution needs to be constructed, where the level is determined by differential pressure of dip tubes. Several calibration curves are usually employed, but it's not explicitly decided how many segment are used, where to select segment, or what should be the degree of polynomial curve. These parameters, i.e., segment and degree of polynomial curve are mutually interrelated to give the better performance of calibration curve. Here we present the construction technique of giving optimum calibration curves and their characteristics. (author)

  3. MICA: Multiple interval-based curve alignment

    Science.gov (United States)

    Mann, Martin; Kahle, Hans-Peter; Beck, Matthias; Bender, Bela Johannes; Spiecker, Heinrich; Backofen, Rolf

    2018-01-01

    MICA enables the automatic synchronization of discrete data curves. To this end, characteristic points of the curves' shapes are identified. These landmarks are used within a heuristic curve registration approach to align profile pairs by mapping similar characteristics onto each other. In combination with a progressive alignment scheme, this enables the computation of multiple curve alignments. Multiple curve alignments are needed to derive meaningful representative consensus data of measured time or data series. MICA was already successfully applied to generate representative profiles of tree growth data based on intra-annual wood density profiles or cell formation data. The MICA package provides a command-line and graphical user interface. The R interface enables the direct embedding of multiple curve alignment computation into larger analyses pipelines. Source code, binaries and documentation are freely available at https://github.com/BackofenLab/MICA

  4. Inverse Diffusion Curves Using Shape Optimization.

    Science.gov (United States)

    Zhao, Shuang; Durand, Fredo; Zheng, Changxi

    2018-07-01

    The inverse diffusion curve problem focuses on automatic creation of diffusion curve images that resemble user provided color fields. This problem is challenging since the 1D curves have a nonlinear and global impact on resulting color fields via a partial differential equation (PDE). We introduce a new approach complementary to previous methods by optimizing curve geometry. In particular, we propose a novel iterative algorithm based on the theory of shape derivatives. The resulting diffusion curves are clean and well-shaped, and the final image closely approximates the input. Our method provides a user-controlled parameter to regularize curve complexity, and generalizes to handle input color fields represented in a variety of formats.

  5. Benefit of cone-beam computed tomography angiography in acute management of angiographically undetectable ruptured arteriovenous malformations.

    Science.gov (United States)

    Rahal, Jason P; Malek, Adel M

    2013-10-01

    Ruptured arteriovenous malformations (AVMs) are a frequent cause of intracerebral hemorrhage (ICH). In some cases, compression from the associated hematoma in the acute setting can partially or completely occlude an AVM, making it invisible on conventional angiography techniques. The authors report on the successful use of cone-beam CT angiography (CBCT-A) to precisely identify the underlying angioarchitecture of ruptured AVMs that are not visible on conventional angiography. Three patients presented with ICH for which they underwent examination with CBCT-A in addition to digital subtraction angiography and other imaging modalities, including MR angiography and CT angiography. All patients underwent surgical evacuation due to mass effect from the hematoma. Clinical history, imaging studies, and surgical records were reviewed. Hematoma volumes were calculated. In all 3 cases, CBCT-A demonstrated detailed anatomy of an AVM where no lesion or just a suggestion of a draining vein had been seen with other imaging modalities. Magnetic resonance imaging demonstrated enhancement in 1 patient; CT angiography demonstrated a draining vein in 1 patient; 2D digital subtraction angiography and 3D rotational angiography demonstrated a suggestion of a draining vein in 2 cases and no finding in the third. In the 2 patients in whom CBCT-A was performed prior to surgery, the demonstrated AVM was successfully resected without evidence of a residual lesion. In the third patient, CBCT-A allowed precise targeting of the AVM nidus using Gamma Knife radiosurgery. Cone-beam CT angiography should be considered in the evaluation and subsequent treatment of ICH due to ruptured AVMs. In cases in which the associated hematoma compresses the AVM nidus, CBCT-A can have higher sensitivity and anatomical accuracy than traditional angiographic modalities, including digital subtraction angiography.

  6. Lipoprotein subclasses in the Monitored Atherosclerosis Regression Study (MARS). Treatment effects and relation to coronary angiographic progression.

    Science.gov (United States)

    Mack, W J; Krauss, R M; Hodis, H N

    1996-05-01

    Accumulating evidence suggests that triglyceride-rich lipoproteins contribute to coronary artery disease. Using data from the Monitored Atherosclerosis Regression Study, an angiographic trial of middle-aged men and women randomized to lovastatin or placebo, we investigated relationships between lipoprotein subclasses and progression of coronary artery atherosclerosis. Coronary artery lesion progression was determined by quantitative coronary angiography in low-grade ( or = 50% diameter stenosis), and all coronary artery lesions in 220 baseline/2-year angiogram pairs. Analytical ultracentrifugation was used to measure lipoprotein masses that were statistically evaluated for treatment group differences and relationships to progression of coronary artery atherosclerosis. All low density lipoprotein (LDL), intermediate density lipoprotein (IDL), and very low density lipoprotein (VLDL) masses were significantly lowered and all high density lipoprotein (HDL) masses were significantly raised with lovastatin therapy. The mass of smallest LDL (Svedberg flotation rate [Sf] 0 to 3), IDL (Sf 12 to 20), all VLDL subclasses (Sf 20 to 60, Sf 60 to 100, and Sf 100 to 400), and peak LDL flotation rate were significantly related to the progression of coronary artery lesions, specifically low-grade lesions. Greater baseline levels of HDL3, were related to a lower likelihood of coronary artery lesion progression. In multivariate analyses, small VLDL (Sf 20 to 60) and HDL3 mass were the most important correlates of coronary artery lesion progression. These results provide further evidence for the importance of triglyceride-rich lipoproteins in the progression of coronary artery disease. In addition, these results present new evidence for the possible protective role of HDL3 in the progression of coronary artery lesions. More specific information on coronary artery lesion progression may be obtained through the study of specific apolipoprotein B-containing lipoproteins.

  7. Angiographic frequency of blunt cerebrovascular injury in patients with carotid canal or vertebral foramen fractures on multidetector CT

    International Nuclear Information System (INIS)

    McKinney, Alexander; Ott, Frederick; Short, James; McKinney, Zeke; Truwit, Charles

    2007-01-01

    Purpose: Blunt carotid injuries (BCI's) and blunt vertebral artery injuries (BVI's), known jointly as BCVI's, are common in 'high risk' patients. The purpose is to evaluate the rate of occurrence of BCI/BVI in patients screened purely by the radiologic criteria of fracture through the carotid canal or vertebral transverse foramina, or significant cervical subluxation, noted by multidetector CT. Methods: Seventy-one patients with 108 catheterized vessels were included over a 13-month interval. The angiographic examinations were prompted by current hospital protocol, solely by the presence of fractures involving/adjacent to the carotid canal, cervical fractures involving/adjacent to the foramen transversarium, or cervical fractures with significant subluxation. The incidence of each grade of blunt injury was calculated after review of the CT scans and catheter angiograms by two neuroradiologists. Results: Two thousand and seventy-three total blunt trauma admissions occurred during the time period, with a BCVI rate of 0.92-1.0% (depending on the reviewer), similar to previous studies. Mean time to catheter angiography was 16.6 h. Of the 71 included patients, there were 11-12 BCI's and 10-12 BVI's, an overall rate of 27-30% of BCVI in the patients with foraminal fractures. Interobserver agreement in reviewing the catheter angiograms was excellent (Kappa 0.795). Of note, three internal carotid pseudoaneurysms resolved spontaneously after anticoagulation or aspirin. Conclusion: This study confirms that there is a high rate of BCVI in the presence of carotid canal or vertebral foramen fractures that are noted by multidetector CT. Utilization of purely radiologic criteria of foraminal involvement may be a significant screening tool in the decision of whether to evaluate these patients acutely by catheter or CT angiography, and for early detection of patients at risk for symptomatology, to initiate prompt, prophylactic treatment

  8. Angiographic frequency of blunt cerebrovascular injury in patients with carotid canal or vertebral foramen fractures on multidetector CT

    Energy Technology Data Exchange (ETDEWEB)

    McKinney, Alexander [Department of Radiology, Hennepin County and University of Minnesota-Fairview and Medical Centers, Minneapolis, MN (United States)]. E-mail: mckin022@umn.edu; Ott, Frederick [Department of Radiology, Hennepin County and University of Minnesota-Fairview and Medical Centers, Minneapolis, MN (United States); Short, James [Department of Radiology, Hennepin County and University of Minnesota-Fairview and Medical Centers, Minneapolis, MN (United States); McKinney, Zeke [Department of Radiology, Hennepin County and University of Minnesota-Fairview and Medical Centers, Minneapolis, MN (United States); Truwit, Charles [Department of Radiology, Hennepin County and University of Minnesota-Fairview and Medical Centers, Minneapolis, MN (United States)

    2007-06-15

    Purpose: Blunt carotid injuries (BCI's) and blunt vertebral artery injuries (BVI's), known jointly as BCVI's, are common in 'high risk' patients. The purpose is to evaluate the rate of occurrence of BCI/BVI in patients screened purely by the radiologic criteria of fracture through the carotid canal or vertebral transverse foramina, or significant cervical subluxation, noted by multidetector CT. Methods: Seventy-one patients with 108 catheterized vessels were included over a 13-month interval. The angiographic examinations were prompted by current hospital protocol, solely by the presence of fractures involving/adjacent to the carotid canal, cervical fractures involving/adjacent to the foramen transversarium, or cervical fractures with significant subluxation. The incidence of each grade of blunt injury was calculated after review of the CT scans and catheter angiograms by two neuroradiologists. Results: Two thousand and seventy-three total blunt trauma admissions occurred during the time period, with a BCVI rate of 0.92-1.0% (depending on the reviewer), similar to previous studies. Mean time to catheter angiography was 16.6 h. Of the 71 included patients, there were 11-12 BCI's and 10-12 BVI's, an overall rate of 27-30% of BCVI in the patients with foraminal fractures. Interobserver agreement in reviewing the catheter angiograms was excellent (Kappa 0.795). Of note, three internal carotid pseudoaneurysms resolved spontaneously after anticoagulation or aspirin. Conclusion: This study confirms that there is a high rate of BCVI in the presence of carotid canal or vertebral foramen fractures that are noted by multidetector CT. Utilization of purely radiologic criteria of foraminal involvement may be a significant screening tool in the decision of whether to evaluate these patients acutely by catheter or CT angiography, and for early detection of patients at risk for symptomatology, to initiate prompt, prophylactic treatment.

  9. Ionizing secondary radiation generated by analog radiological and digital coronary cine angiographic equipment. Influence of external protection devices

    International Nuclear Information System (INIS)

    Ramirez N, Alfredo; Farias Ch, Eric; Silva J, Ana Maria; Leyton L, Fernando; Oyarzun C, Carlos; Ugalde P, Hector; Dussaillant, Gaston; Cumsille G, Angel

    2000-01-01

    Exposure to ionizing radiation is a know hazard of radiological procedures. Aim: to compare the emission of secondary ionizing radiation from two coronary angiographic equipments, one with digital and the other with analog image generation. To evaluate the effectiveness of external radiological protection devices. Material and methods: environmental and fluoroscopy generated radiation in the cephalic region of the patient was measured during diagnostic coronary angiographies. Ionizing radiation generated in anterior left oblique protection (ALO) and anterior right oblique protection (ARO) were measured with and without leaded protections. In 19 patients (group 1), a digital equipment was used and in 21 (group 2), an analog equipment. Results: header radiation for group 1 and 2 was 1194±337 and 364±222 μGray/h respectively (p≤0.001). During fluoroscopy and with leaded protection generated radiation for groups 1 and 2 was 612±947 and 70±61μGray/h respectively (p≤0.001). For ALO projection, generated for groups 1 and 2 was 105±47 and 71±192 μGray/h respectively (p≤0.001). During filming the radiation for ALO projection for groups 1 and 2 was 7252±9569 and 1671±2038 μGray/h respectively (p=0.03). Out of the protection zone, registered radiation during fluoroscopy for groups 1 and 2 was 2800±1741 and 1318±954 μGray/h respectively (p≤0.001); during filming, the figures were 15500±5840 and 18961±10599 μGray/h respectively (NS). Conclusions: digital radiological equipment has a lower level of ionizing radiation emission than the analog equipment

  10. Positive exercise thallium-201 test responses in patients with less than 50% maximal coronary stenosis: angiographic and clinical predictors

    International Nuclear Information System (INIS)

    Brown, K.A.; Osbakken, M.; Boucher, C.A.; Strauss, H.W.; Pohost, G.M.; Okada, R.D.

    1985-01-01

    The incidence and causes of abnormal thallium-201 (TI-201) myocardial perfusion studies in the absence of significant coronary artery disease were examined. The study group consisted of 100 consecutive patients undergoing exercise TI-201 testing and coronary angiography who were found to have maximal coronary artery diameter narrowing of less than 50%. Maximal coronary stenosis ranged from 0 to 40%. The independent and relative influences of patient clinical, exercise and angiographic data were assessed by logistic regression analysis. Significant predictors of a positive stress TI-201 test result were: (1) percent maximal coronary stenosis (p less than 0.0005), (2) propranolol use (p less than 0.01), (3) interaction of propranolol use and percent maximal stenosis (p less than 0.005), and (4) stress-induced chest pain (p . 0.05). No other patient variable had a significant influence. Positive TI-201 test results were more common in patients with 21 to 40% maximal stenosis (59%) than in patients with 0 to 20% maximal stenosis (27%) (p less than 0.01). Among patients with 21 to 40% stenosis, a positive test response was more common when 85% of maximal predicted heart rate was achieved (75%) than when it was not (40%) (p less than 0.05). Of 16 nonapical perfusion defects seen in patients with 21 to 40% maximal stenosis, 14 were in the territory that corresponded with such a coronary stenosis. Patients taking propranolol were more likely to have a positive TI-201 test result (45%) than patients not taking propranolol (22%) (p less than 0.05)

  11. Design considerations for a new, high resolution Micro-Angiographic Fluoroscope based on a CMOS sensor (MAF-CMOS).

    Science.gov (United States)

    Loughran, Brendan; Swetadri Vasan, S N; Singh, Vivek; Ionita, Ciprian N; Jain, Amit; Bednarek, Daniel R; Titus, Albert; Rudin, Stephen

    2013-03-06

    The detectors that are used for endovascular image-guided interventions (EIGI), particularly for neurovascular interventions, do not provide clinicians with adequate visualization to ensure the best possible treatment outcomes. Developing an improved x-ray imaging detector requires the determination of estimated clinical x-ray entrance exposures to the detector. The range of exposures to the detector in clinical studies was found for the three modes of operation: fluoroscopic mode, high frame-rate digital angiographic mode (HD fluoroscopic mode), and DSA mode. Using these estimated detector exposure ranges and available CMOS detector technical specifications, design requirements were developed to pursue a quantum limited, high resolution, dynamic x-ray detector based on a CMOS sensor with 50 μm pixel size. For the proposed MAF-CMOS, the estimated charge collected within the full exposure range was found to be within the estimated full well capacity of the pixels. Expected instrumentation noise for the proposed detector was estimated to be 50-1,300 electrons. Adding a gain stage such as a light image intensifier would minimize the effect of the estimated instrumentation noise on total image noise but may not be necessary to ensure quantum limited detector operation at low exposure levels. A recursive temporal filter may decrease the effective total noise by 2 to 3 times, allowing for the improved signal to noise ratios at the lowest estimated exposures despite consequent loss in temporal resolution. This work can serve as a guide for further development of dynamic x-ray imaging prototypes or improvements for existing dynamic x-ray imaging systems.

  12. String Sigma Models on Curved Supermanifolds

    Directory of Open Access Journals (Sweden)

    Roberto Catenacci

    2018-04-01

    Full Text Available We use the techniques of integral forms to analyze the easiest example of two-dimensional sigma models on a supermanifold. We write the action as an integral of a top integral form over a D = 2 supermanifold, and we show how to interpolate between different superspace actions. Then, we consider curved supermanifolds, and we show that the definitions used for flat supermanifolds can also be used for curved supermanifolds. We prove it by first considering the case of a curved rigid supermanifold and then the case of a generic curved supermanifold described by a single superfield E.

  13. Regional Marginal Abatement Cost Curves for NOx

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data underlying the figures included in the manuscript "Marginal abatement cost curve for NOx incorporating controls, renewable electricity, energy efficiency and...

  14. NEW CONCEPTS AND TEST METHODS OF CURVE PROFILE AREA DENSITY IN SURFACE: ESTIMATION OF AREAL DENSITY ON CURVED SPATIAL SURFACE

    OpenAIRE

    Hong Shen

    2011-01-01

    The concepts of curve profile, curve intercept, curve intercept density, curve profile area density, intersection density in containing intersection (or intersection density relied on intersection reference), curve profile intersection density in surface (or curve intercept intersection density relied on intersection of containing curve), and curve profile area density in surface (AS) were defined. AS expressed the amount of curve profile area of Y phase in the unit containing surface area, S...

  15. Polar representation of centrifugal pump homologous curves

    International Nuclear Information System (INIS)

    Veloso, Marcelo Antonio; Mattos, Joao Roberto Loureiro de

    2008-01-01

    Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic parameters: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. Any one of these quantities can be expressed as a function of any two others. The curves showing the relationships between these four variables are called the pump characteristic curves, also referred to as four-quadrant curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, the four-quadrant configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the polar form appears as the simplest way to represent the homologous curves. In the polar method, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a

  16. Prediction of optimal deployment projection for transcatheter aortic valve replacement: angiographic 3-dimensional reconstruction of the aortic root versus multidetector computed tomography.

    Science.gov (United States)

    Binder, Ronald K; Leipsic, Jonathon; Wood, David; Moore, Teri; Toggweiler, Stefan; Willson, Alex; Gurvitch, Ronen; Freeman, Melanie; Webb, John G

    2012-04-01

    Identifying the optimal fluoroscopic projection of the aortic valve is important for successful transcatheter aortic valve replacement (TAVR). Various imaging modalities, including multidetector computed tomography (MDCT), have been proposed for prediction of the optimal deployment projection. We evaluated a method that provides 3-dimensional angiographic reconstructions (3DA) of the aortic root for prediction of the optimal deployment angle and compared it with MDCT. Forty patients undergoing transfemoral TAVR at St Paul's Hospital, Vancouver, Canada, were evaluated. All underwent preimplant 3DA and 68% underwent preimplant MDCT. Three-dimensional angiographic reconstructions were generated from images of a C-arm rotational aortic root angiogram during breath-hold, rapid ventricular pacing, and injection of 32 mL contrast medium at 8 mL/s. Two independent operators prospectively predicted perpendicular valve projections. The implant angle was chosen at the discretion of the physician performing TAVR. The angles from 3DA, from MDCT, the implant angle, and the postdeployment perpendicular prosthesis view were compared. The shortest distance from the postdeployment perpendicular prosthesis projection to the regression line of predicted perpendicular projections was calculated. All but 1 patient had adequate image quality for reproducible angle predictions. There was a significant correlation between 3DA and MDCT for prediction of perpendicular valve projections (r=0.682, Pregression line of predicted angles to the postdeployment prosthesis view was 5.1±4.6° for 3DA and 7.9±4.9° for MDCT (P=0.01). Three-dimensional angiographic reconstructions and MDCT are safe, practical, and accurate imaging modalities for identifying the optimal perpendicular valve deployment projection during TAVR.

  17. Time to Angiographic Reperfusion and Clinical Outcome after Acute Ischemic Stroke in the Interventional Management of Stroke Phase III (IMS III) Trial: A Validation Study

    Science.gov (United States)

    Khatri, Pooja; Yeatts, Sharon D.; Mazighi, Mikael; Broderick, Joseph P.; Liebeskind, David S.; Demchuk, Andrew M.; Amarenco, Pierre; Carrozzella, Janice; Spilker, Judith; Foster, Lydia D.; Goyal, Mayank; Hill, Michael D.; Palesch, Yuko Y.; Jauch, Edward C.; Haley, E. Clarke; Vagal, Achala; Tomsick, Thomas A.

    2014-01-01

    BACKGROUND The IMS III Trial did not demonstrate clinical benefit of the endovascular approach compared to IV rt-PA alone for moderate or severe ischemic strokes (NIHSS≥8) enrolled within three hours of stroke onset. Late reperfusion of tissue that is no longer salvageable may be one explanation, as suggested by prior exploratory studies showing an association between time to reperfusion and good clinical outcome. We sought to validate this relationship in the large-scale IMS III trial, and consider its implications for future endovascular trials. METHODS The analysis consisted of the endovascular cohort with proximal arterial occlusions in the anterior circulation that achieved angiographic reperfusion (TICI 2–3) during the endovascular procedure (within 7 hours from the onset of symptoms). Logistic regression was used to model good clinical outcome (90-day modified Rankin 0–2) as a function of the time to reperfusion, and prespecified variables were considered for adjustment. FINDINGS Among 240 proximal vessel occlusions, angiographic reperfusion (TICI 2–3) was achieved in 182 (76%). Mean time to reperfusion was 325 minutes (range 180–418 minutes). Longer time for reperfusion was associated with a decreased likelihood of good clinical outcome (RR [95% CI] for every 30 minute delay: unadjusted 0·85 [0·77–0·94]; adjusted 0·88 [0·80–0·98]). INTERPRETATION We confirm that delay in time to angiographic reperfusion leads to a decreased likelihood of good clinical outcome. Achieving rapid reperfusion may be critical for the successes of future acute endovascular trials. FUNDING: NIH/NINDS (study sponsor), Genentech Inc. (study drug - intra-arterial t-PA), EKOS Corp. (device), Concentric Inc. (device), Cordis Neurovascular, Inc. (device), and Boehringer Ingelheim (European Investigator Meeting support). PMID:24784550

  18. Correlation of C-Reactive Protein and Cardiac Enzymes with Angiographic Severity of Coronary Artery Disease in Pakistani Patients with Acute Coronary Syndrome

    International Nuclear Information System (INIS)

    Saleem, A.; Ali, A.

    2017-01-01

    Objective: To determine the correlation of C-reactive protein (CRP) levels with the severity of coronary stenosis on angiography and the association of cardiac enzymes with the degree of stenosis in acute coronary syndrome (ACS) patients. Secondly, to compare association of angiographic severity of vascular stenosis with CRP in patients with ST segment elevation myocardial infarction (STEMI) and non-STEMI / Unstable angina (UA). Study Design: Prospective, descriptive study. Place and Duration of Study: Khan Research Laboratories (KRL) Hospital, from October 2014 to March 2015. Methodology: CRP was measured on diagnosis of ACS in 70 patients. Cardiac enzymes were measured 6 hours after the onset of chest pain. Angiographic scoring for degree of stenosis and number of culprit vessels was done. Two groups consisting of patients with STEMI (group 1) and with NSTEMI/UA (group 2) were made. Results: No correlation was found between CRP levels and angiographic stenosis in patients with ACS (r=0.162, p>0.05). No association was found between eosinophil count and severity of stenosis (p=0.88). Rise of cardiac enzymes and degree of coronary stenosis showed a positive correlation (p <0.001). There was significant difference in the means of coronary artery stenosis scores between the two groups (Gensini score of groups 1 and 2: 35.9 +- 4 and 14 +- 8, respectively) p<0.001, but there was no significant difference in CRP levels. Conclusion: CRP is a marker of inflammation in ACS rather than a risk factor for determining the severity of vascular stenosis. Rise in cardiac enzymes still grade high in predicting severity of vascular stenosis than eosinophil count or CRP levels. (author)

  19. Migration and the Wage-Settings Curve

    DEFF Research Database (Denmark)

    Brücker, Herbert; Jahn, Elke

    Germany on basis of a wage-setting curve. The wage-setting curve relies on the assumption that wages respond to a hange in the unemployment rate, albeit imperfectly. This allows one to derive the wage and employment effects of migration simultaneously in a general equilibrium framework. Using...

  20. Learning curves in energy planning models

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, L; Kypreos, S [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    This study describes the endogenous representation of investment cost learning curves into the MARKAL energy planning model. A piece-wise representation of the learning curves is implemented using Mixed Integer Programming. The approach is briefly described and some results are presented. (author) 3 figs., 5 refs.

  1. The Koch curve as a smooth manifold

    International Nuclear Information System (INIS)

    Epstein, Marcelo; Sniatycki, Jedrzej

    2008-01-01

    We show that there exists a homeomorphism between the closed interval [0,1] is contained in R and the Koch curve endowed with the subset topology of R 2 . We use this homeomorphism to endow the Koch curve with the structure of a smooth manifold with boundary

  2. Fermionic fields on ZN-curves

    International Nuclear Information System (INIS)

    Bershadsky, M.; Radul, A.

    1988-01-01

    The line bundles of degree g-1 on Z N -curves corresponding to 1/N nonsingular characteristics are considered. The determinants of Dirac operators defined on these line bundles are evaluated in terms of branch points. The generalization of Thomae's formula for Z N -curves is derived. (orig.)

  3. Measuring Model Rocket Engine Thrust Curves

    Science.gov (United States)

    Penn, Kim; Slaton, William V.

    2010-01-01

    This paper describes a method and setup to quickly and easily measure a model rocket engine's thrust curve using a computer data logger and force probe. Horst describes using Vernier's LabPro and force probe to measure the rocket engine's thrust curve; however, the method of attaching the rocket to the force probe is not discussed. We show how a…

  4. A minicourse on moduli of curves

    International Nuclear Information System (INIS)

    Looijenga, E.

    2000-01-01

    These are notes that accompany a short course given at the School on Algebraic Geometry 1999 at the ICTP, Trieste. A major goal is to outline various approaches to moduli spaces of curves. In the last part I discuss the algebraic classes that naturally live on these spaces; these can be thought of as the characteristic classes for bundles of curves. (author)

  5. Minimal families of curves on surfaces

    KAUST Repository

    Lubbes, Niels

    2014-01-01

    A minimal family of curves on an embedded surface is defined as a 1-dimensional family of rational curves of minimal degree, which cover the surface. We classify such minimal families using constructive methods. This allows us to compute the minimal

  6. Symmetry Properties of Potentiometric Titration Curves.

    Science.gov (United States)

    Macca, Carlo; Bombi, G. Giorgio

    1983-01-01

    Demonstrates how the symmetry properties of titration curves can be efficiently and rigorously treated by means of a simple method, assisted by the use of logarithmic diagrams. Discusses the symmetry properties of several typical titration curves, comparing the graphical approach and an explicit mathematical treatment. (Author/JM)

  7. Deep-learnt classification of light curves

    DEFF Research Database (Denmark)

    Mahabal, Ashish; Gieseke, Fabian; Pai, Akshay Sadananda Uppinakudru

    2017-01-01

    Astronomy light curves are sparse, gappy, and heteroscedastic. As a result standard time series methods regularly used for financial and similar datasets are of little help and astronomers are usually left to their own instruments and techniques to classify light curves. A common approach is to d...

  8. Hyper-and-elliptic-curve cryptography

    NARCIS (Netherlands)

    Bernstein, D.J.; Lange, T.

    2014-01-01

    This paper introduces ‘hyper-and-elliptic-curve cryptography’, in which a single high-security group supports fast genus-2-hyperelliptic-curve formulas for variable-base-point single-scalar multiplication (for example, Diffie–Hellman shared-secret computation) and at the same time supports fast

  9. Curve Matching with Applications in Medical Imaging

    DEFF Research Database (Denmark)

    Bauer, Martin; Bruveris, Martins; Harms, Philipp

    2015-01-01

    In the recent years, Riemannian shape analysis of curves and surfaces has found several applications in medical image analysis. In this paper we present a numerical discretization of second order Sobolev metrics on the space of regular curves in Euclidean space. This class of metrics has several...

  10. Remote sensing used for power curves

    International Nuclear Information System (INIS)

    Wagner, R; Joergensen, H E; Paulsen, U S; Larsen, T J; Antoniou, I; Thesbjerg, L

    2008-01-01

    Power curve measurement for large wind turbines requires taking into account more parameters than only the wind speed at hub height. Based on results from aerodynamic simulations, an equivalent wind speed taking the wind shear into account was defined and found to reduce the power standard deviation in the power curve significantly. Two LiDARs and a SoDAR are used to measure the wind profile in front of a wind turbine. These profiles are used to calculate the equivalent wind speed. The comparison of the power curves obtained with the three instruments to the traditional power curve, obtained using a cup anemometer measurement, confirms the results obtained from the simulations. Using LiDAR profiles reduces the error in power curve measurement, when these are used as relative instrument together with a cup anemometer. Results from the SoDAR do not show such promising results, probably because of noisy measurements resulting in distorted profiles

  11. Parametric representation of centrifugal pump homologous curves

    International Nuclear Information System (INIS)

    Veloso, Marcelo A.; Mattos, Joao R.L. de

    2015-01-01

    Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic quantities: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. The curves showing the relationships between these four variables are called the pump characteristic curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, this configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the parametric form appears as the simplest way to deal with the homologous curves. In this approach, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a pressurized water reactor (PWR) are transformed to the parametric form. (author)

  12. Computerised curve deconvolution of TL/OSL curves using a popular spreadsheet program.

    Science.gov (United States)

    Afouxenidis, D; Polymeris, G S; Tsirliganis, N C; Kitis, G

    2012-05-01

    This paper exploits the possibility of using commercial software for thermoluminescence and optically stimulated luminescence curve deconvolution analysis. The widely used software package Microsoft Excel, with the Solver utility has been used to perform deconvolution analysis to both experimental and reference glow curves resulted from the GLOw Curve ANalysis INtercomparison project. The simple interface of this programme combined with the powerful Solver utility, allows the analysis of complex stimulated luminescence curves into their components and the evaluation of the associated luminescence parameters.

  13. Computerised curve deconvolution of TL/OSL curves using a popular spreadsheet program

    International Nuclear Information System (INIS)

    Afouxenidis, D.; Polymeris, G. S.; Tsirliganis, N. C.; Kitis, G.

    2012-01-01

    This paper exploits the possibility of using commercial software for thermoluminescence and optically stimulated luminescence curve deconvolution analysis. The widely used software package Microsoft Excel, with the Solver utility has been used to perform deconvolution analysis to both experimental and reference glow curves resulted from the Glow Curve Analysis Intercomparison project. The simple interface of this programme combined with the powerful Solver utility, allows the analysis of complex stimulated luminescence curves into their components and the evaluation of the associated luminescence parameters. (authors)

  14. Mannheim Partner D-Curves in the Euclidean 3-space

    Directory of Open Access Journals (Sweden)

    Mustafa Kazaz

    2015-02-01

    Full Text Available In this paper, we consider the idea of Mannheim partner curves for curves lying on surfaces. By considering the Darboux frames of surface curves, we define Mannheim partner D-curves and give the characterizations for these curves. We also find the relations between geodesic curvatures, normal curvatures and geodesic torsions of these associated curves. Furthermore, we show that definition and characterizations of Mannheim partner D-curves include those of Mannheim partner curves in some special cases.

  15. A versatile curve-fit model for linear to deeply concave rank abundance curves

    NARCIS (Netherlands)

    Neuteboom, J.H.; Struik, P.C.

    2005-01-01

    A new, flexible curve-fit model for linear to concave rank abundance curves was conceptualized and validated using observational data. The model links the geometric-series model and log-series model and can also fit deeply concave rank abundance curves. The model is based ¿ in an unconventional way

  16. Investigation of learning and experience curves

    Energy Technology Data Exchange (ETDEWEB)

    Krawiec, F.; Thornton, J.; Edesess, M.

    1980-04-01

    The applicability of learning and experience curves for predicting future costs of solar technologies is assessed, and the major test case is the production economics of heliostats. Alternative methods for estimating cost reductions in systems manufacture are discussed, and procedures for using learning and experience curves to predict costs are outlined. Because adequate production data often do not exist, production histories of analogous products/processes are analyzed and learning and aggregated cost curves for these surrogates estimated. If the surrogate learning curves apply, they can be used to estimate solar technology costs. The steps involved in generating these cost estimates are given. Second-generation glass-steel and inflated-bubble heliostat design concepts, developed by MDAC and GE, respectively, are described; a costing scenario for 25,000 units/yr is detailed; surrogates for cost analysis are chosen; learning and aggregate cost curves are estimated; and aggregate cost curves for the GE and MDAC designs are estimated. However, an approach that combines a neoclassical production function with a learning-by-doing hypothesis is needed to yield a cost relation compatible with the historical learning curve and the traditional cost function of economic theory.

  17. Modelling curves of manufacturing feasibilities and demand

    Directory of Open Access Journals (Sweden)

    Soloninko K.S.

    2017-03-01

    Full Text Available The authors research the issue of functional properties of curves of manufacturing feasibilities and demand. Settlement of the problem, and its connection with important scientific and practical tasks. According to its nature, the market economy is unstable and is in constant movement. Economy has an effective instrument for explanation of changes in economic environment; this tool is called the modelling of economic processes. The modelling of economic processes depends first and foremost on the building of economic model which is the base for the formalization of economic process, that is, the building of mathematical model. The effective means for formalization of economic process is the creation of the model of hypothetic or imaginary economy. The building of demand model is significant for the market of goods and services. The problem includes the receiving (as the result of modelling definite functional properties of curves of manufacturing feasibilities and demand according to which one can determine their mathematical model. Another problem lies in obtaining majorant properties of curves of joint demand on the market of goods and services. Analysis of the latest researches and publications. Many domestic and foreign scientists dedicated their studies to the researches and building of the models of curves of manufacturing feasibilities and demand. In spite of considerable work of the scientists, such problems as functional properties of the curves and their practical use in modelling. The purpose of the article is to describe functional properties of curves of manufacturing feasibilities and demand on the market of goods and services on the base of modelling of their building. Scientific novelty and practical value. The theoretical regulations (for functional properties of curves of manufacturing feasibilities and demand received as a result of the present research, that is convexity, give extra practical possibilities in a microeconomic

  18. Reflected Light Curves of Extrasolar Planets

    Science.gov (United States)

    Green, D.; Matthews, J.; Kuschnig, R.; Seager, S.

    The planned launches of ultra-precise photometric satellites such as MOST, COROT and MONS should provide the first opportunity to study the reflected light curves from extrasolar planets. To predict the capabilities of these missions, we have constructed a series of models of such light curves, improving upon the Monte Carlo simulations by Seager et al. (2000). These models include more realistic features such limb darkening of the star and broad band photometry. For specific models, the resulting planet light curves exhibit unique behavior with the variation of radius, inclination and presence or absence of clouds.

  19. Neck curve polynomials in neck rupture model

    International Nuclear Information System (INIS)

    Kurniadi, Rizal; Perkasa, Yudha S.; Waris, Abdul

    2012-01-01

    The Neck Rupture Model is a model that explains the scission process which has smallest radius in liquid drop at certain position. Old fashion of rupture position is determined randomly so that has been called as Random Neck Rupture Model (RNRM). The neck curve polynomials have been employed in the Neck Rupture Model for calculation the fission yield of neutron induced fission reaction of 280 X 90 with changing of order of polynomials as well as temperature. The neck curve polynomials approximation shows the important effects in shaping of fission yield curve.

  20. Morse theory on timelike and causal curves

    International Nuclear Information System (INIS)

    Everson, J.; Talbot, C.J.

    1976-01-01

    It is shown that the set of timelike curves in a globally hyperbolic space-time manifold can be given the structure of a Hilbert manifold under a suitable definition of 'timelike.' The causal curves are the topological closure of this manifold. The Lorentzian energy (corresponding to Milnor's energy, except that the Lorentzian inner product is used) is shown to be a Morse function for the space of causal curves. A fixed end point index theorem is obtained in which a lower bound for the index of the Hessian of the Lorentzian energy is given in terms of the sum of the orders of the conjugate points between the end points. (author)

  1. Constructing forward price curves in electricity markets

    DEFF Research Database (Denmark)

    Fleten, S.-E.; Lemming, Jørgen Kjærgaard

    2003-01-01

    We present and analyze a method for constructing approximated high-resolution forward price curves in electricity markets. Because a limited number of forward or futures contracts are traded in the market, only a limited picture of the theoretical continuous forward price curve is available...... to the analyst. Our method combines the information contained in observed bid and ask prices with information from the forecasts generated by bottom-up models. As an example, we use information concerning the shape of the seasonal variation from a bottom-up model to improve the forward price curve quoted...

  2. Curves of restricted type in euclidean spaces

    Directory of Open Access Journals (Sweden)

    Bengü Kılıç Bayram

    2014-01-01

    Full Text Available Submanifolds of restricted type were introduced in [7]. In the present study we consider restricted type of curves in Em. We give some special examples. We also show that spherical curve in S2(r C E3 is of restricted type if and only if either ƒ(s is constant or a linear function of s of the form ƒ(s = ±s + b and every closed W - curve of rank k and of length 2(r in E2k is of restricted type.

  3. Constructing forward price curves in electricity markets

    International Nuclear Information System (INIS)

    Fleten, Stein-Erik; Lemming, Jacob

    2003-01-01

    We present and analyze a method for constructing approximated high-resolution forward price curves in electricity markets. Because a limited number of forward or futures contracts are traded in the market, only a limited picture of the theoretical continuous forward price curve is available to the analyst. Our method combines the information contained in observed bid and ask prices with information from the forecasts generated by bottom-up models. As an example, we use information concerning the shape of the seasonal variation from a bottom-up model to improve the forward price curve quoted on the Nordic power exchange

  4. Growth curves for twins in Slovenia.

    Science.gov (United States)

    Bricelj, Katja; Blickstein, Isaac; Bržan-Šimenc, Gabrijela; Janša, Vid; Lučovnik, Miha; Verdenik, Ivan; Trojner-Bregar, Andreja; Tul, Nataša

    2017-02-01

    Abnormalities of fetal growth are more common in twins. We introduce the growth curves for monitoring fetal growth in twin pregnancies in Slovenia. Slovenian National Perinatal Information System for the period between 2002 and 2010 was used to calculate birth weight percentiles for all live born twins for each week from 22nd to 40th week. The calculated percentiles of birth weight for all live-born twins in Slovenia served as the basis for drawing 'growth' curves. The calculated growth curves for twins will help accurately diagnose small or large twin fetuses for their gestational age in the native central European population.

  5. Wind Turbine Power Curves Incorporating Turbulence Intensity

    DEFF Research Database (Denmark)

    Sørensen, Emil Hedevang Lohse

    2014-01-01

    . The model and method are parsimonious in the sense that only a single function (the zero-turbulence power curve) and a single auxiliary parameter (the equivalent turbulence factor) are needed to predict the mean power at any desired turbulence intensity. The method requires only ten minute statistics......The performance of a wind turbine in terms of power production (the power curve) is important to the wind energy industry. The current IEC-61400-12-1 standard for power curve evaluation recognizes only the mean wind speed at hub height and the air density as relevant to the power production...

  6. The association of age-related maculopathy susceptibility 2 (ARMS2) and complement factor H (CFH) variants with two angiographic subtypes of polypoidal choroidal vasculopathy.

    Science.gov (United States)

    Miki, Akiko; Honda, Shigeru; Kondo, Naoshi; Negi, Akira

    2013-09-01

    To compare the association of age-related maculopathy susceptibility 2 (ARMS2) and complement factor H (CFH) variants between two different angiographic phenotypes of polypoidal choroidal vasculopathy (PCV). We included 175 Japanese patients with PCV and 150 age- and sex-matched controls. PCV was classified into two phenotypes (Type 1 and Type 2) according to the presence or absence of the feeding vessels found in indocyanine-green angiography. The single nucleotide polymorphism (SNP) at rs10490924 (A69S) in ARMS2 and rs800292 (I62V), rs1061170 (Y402H) in the CFH region were genotyped using the TaqMan assay. The minor allele frequency (MAF) of rs10490924 was significantly different between Type 1 PCV (n = 81) and control (p < 0.0001), while no difference was found between Type 2 PCV (n = 94) and control (p = 0.20). The MAF of rs800292 was significantly different between each type of PCV and control (p < 0.0001 and 0.0001 for Type 1 versus control and Type 2 versus control, respectively). The MAF of rs1061170 was not significantly different between either type of PCV and control (p = 0.084 and 0.15, respectively). There may be significantly different associations in the genetic variants of ARMS2 between two angiographic phenotypes of PCV.

  7. Quantification of myocardial area at risk in the absence of collateral flow: the validation of angiographic scores by myocardial perfusion single-photon emission computed tomography.

    Science.gov (United States)

    Rodríguez-Palomares, José F; Alonso, Albert; Martí, Gerard; Aguadé-Bruix, Santiago; González-Alujas, M T; Romero-Farina, Guillermo; Candell-Riera, Jaume; García del Blanco, Bruno; Evangelista, Artur; García-Dorado, David

    2013-02-01

    Our study aimed to compare the area at risk (AAR) determined by single-photon emission computed tomography (SPECT) with the Bypass Angioplasty Revascularization Investigation (BARI) and modified Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) angiographic scores in the setting of patients undergoing coronary angioplasty for either unstable angina or an STEMI. Radionuclide myocardial perfusion imaging prior to reperfusion has classically been the most widely practised technique for assessing the AAR and has been successfully used to compare the efficacy of various reperfusion strategies in patients with an ST-segment elevation myocardial infarction (STEMI). The BARI and modified APPROACH scores are angiographic methods widely used to provide a rapid estimation of the AAR; however, they have not been directly validated with myocardial perfusion single-photon emission computed tomography (SPECT). Fifty-five patients with no previous myocardial infarction who underwent coronary angioplasty for single-vessel disease (unstable angina: n = 25 or an STEMI: n = 30) with no evidence of collaterals (Rentrop Collateral Score collateral flow, BARI and APPROACH scores constitute valid methods for AAR estimation in current clinical practice, with more accurate results when used for the LAD territory; both are useful not only in STEMI patients but also in patients with unstable angina.

  8. Technological change in energy systems. Learning curves, logistic curves and input-output coefficients

    International Nuclear Information System (INIS)

    Pan, Haoran; Koehler, Jonathan

    2007-01-01

    Learning curves have recently been widely adopted in climate-economy models to incorporate endogenous change of energy technologies, replacing the conventional assumption of an autonomous energy efficiency improvement. However, there has been little consideration of the credibility of the learning curve. The current trend that many important energy and climate change policy analyses rely on the learning curve means that it is of great importance to critically examine the basis for learning curves. Here, we analyse the use of learning curves in energy technology, usually implemented as a simple power function. We find that the learning curve cannot separate the effects of price and technological change, cannot reflect continuous and qualitative change of both conventional and emerging energy technologies, cannot help to determine the time paths of technological investment, and misses the central role of R and D activity in driving technological change. We argue that a logistic curve of improving performance modified to include R and D activity as a driving variable can better describe the cost reductions in energy technologies. Furthermore, we demonstrate that the top-down Leontief technology can incorporate the bottom-up technologies that improve along either the learning curve or the logistic curve, through changing input-output coefficients. An application to UK wind power illustrates that the logistic curve fits the observed data better and implies greater potential for cost reduction than the learning curve does. (author)

  9. A simple Lissajous curves experimental setup

    Science.gov (United States)

    Şahin Kızılcık, Hasan; Damlı, Volkan

    2018-05-01

    The aim of this study is to develop an experimental setup to produce Lissajous curves. The setup was made using a smartphone, a powered speaker (computer speaker), a balloon, a laser pointer and a piece of mirror. Lissajous curves are formed as follows: a piece of mirror is attached to a balloon. The balloon is vibrated with the sound signal provided by the speaker that is connected to a smartphone. The laser beam is reflected off the mirror and the reflection is shaped as a Lissajous curve. Because of the intersection of two frequencies (frequency of the sound signal and natural vibration frequency of the balloon), these curves are formed. They can be used to measure the ratio of frequencies.

  10. On ``minimally curved spacetimes'' in general relativity

    OpenAIRE

    Dadhich, Naresh

    1997-01-01

    We consider a spacetime corresponding to uniform relativistic potential analogus to Newtonian potential as an example of ``minimally curved spacetime''. We also consider a radially symmetric analogue of the Rindler spacetime of uniform proper acceleration relative to infinity.

  11. Utilization of curve offsets in additive manufacturing

    Science.gov (United States)

    Haseltalab, Vahid; Yaman, Ulas; Dolen, Melik

    2018-05-01

    Curve offsets are utilized in different fields of engineering and science. Additive manufacturing, which lately becomes an explicit requirement in manufacturing industry, utilizes curve offsets widely. One of the necessities of offsetting is for scaling which is required if there is shrinkage after the fabrication or if the surface quality of the resulting part is unacceptable. Therefore, some post-processing is indispensable. But the major application of curve offsets in additive manufacturing processes is for generating head trajectories. In a point-wise AM process, a correct tool-path in each layer can reduce lots of costs and increase the surface quality of the fabricated parts. In this study, different curve offset generation algorithms are analyzed to show their capabilities and disadvantages through some test cases and improvements on their drawbacks are suggested.

  12. Quaternion orders, quadratic forms, and Shimura curves

    CERN Document Server

    Alsina, Montserrat

    2004-01-01

    Shimura curves are a far-reaching generalization of the classical modular curves. They lie at the crossroads of many areas, including complex analysis, hyperbolic geometry, algebraic geometry, algebra, and arithmetic. The text provides an introduction to the subject from a theoretic and algorithmic perspective. The main topics covered in it are Shimura curves defined over the rational number field, the construction of their fundamental domains, and the determination of their complex multiplication points. The study of complex multiplication points in Shimura curves leads to the study of families of binary quadratic forms with algebraic coefficients and to their classification by arithmetic Fuchsian groups. In this regard, the authors develop a theory full of new possibilities which parallels Gauss' theory on the classification of binary quadratic forms with integral coefficients by the action of the modular group. Each topic covered in the book begins with a theoretical discussion followed by carefully worked...

  13. Uncovering the skewness news impact curve

    Czech Academy of Sciences Publication Activity Database

    Anatolyev, Stanislav; Petukhov, A.

    2016-01-01

    Roč. 14, č. 4 (2016), s. 746-771 ISSN 1479-8409 Institutional support: RVO:67985998 Keywords : conditional skewness * news impact curve * stock returns Subject RIV: AH - Economics Impact factor: 1.800, year: 2016

  14. Classification of ASKAP Vast Radio Light Curves

    Science.gov (United States)

    Rebbapragada, Umaa; Lo, Kitty; Wagstaff, Kiri L.; Reed, Colorado; Murphy, Tara; Thompson, David R.

    2012-01-01

    The VAST survey is a wide-field survey that observes with unprecedented instrument sensitivity (0.5 mJy or lower) and repeat cadence (a goal of 5 seconds) that will enable novel scientific discoveries related to known and unknown classes of radio transients and variables. Given the unprecedented observing characteristics of VAST, it is important to estimate source classification performance, and determine best practices prior to the launch of ASKAP's BETA in 2012. The goal of this study is to identify light curve characterization and classification algorithms that are best suited for archival VAST light curve classification. We perform our experiments on light curve simulations of eight source types and achieve best case performance of approximately 90% accuracy. We note that classification performance is most influenced by light curve characterization rather than classifier algorithm.

  15. Automorphisms of double coverings of curves

    International Nuclear Information System (INIS)

    Torres, F.

    1994-11-01

    We study automorphisms of curves that commute with each other. We prove that the order and the number of fixed points of one of them satisfy certain relations involving those of the other. Then, we specialize our results to the case of double coverings of curves. For instance, if the genus of the curve is at least 4γ + 2 and γ >= 1 (γ = the genus of the covered curve) we prove that the order of an automorphism is bounded above by 2γ + 1 (resp. 4γ + 2) provided it is prime (resp. it has at least five fixed points). We also improve Farkas' bound on the number of fixed points namely 4γ + 4 by showing that it involves the order of the automorphism except in the case of even order when such an improvement is obtained provided the automorphism and the γ-involution has at least one common fixed point. (author). 15 refs

  16. Uncovering the skewness news impact curve

    Czech Academy of Sciences Publication Activity Database

    Anatolyev, Stanislav; Petukhov, A.

    2016-01-01

    Roč. 14, č. 4 (2016), s. 746-771 ISSN 1479-8409 Institutional support: PRVOUK-P23 Keywords : conditional skewness * news impact curve * stock returns Subject RIV: AH - Economics Impact factor: 1.800, year: 2016

  17. Transmission of wave energy in curved ducts

    Science.gov (United States)

    Rostafinski, W.

    1973-01-01

    A formation of wave energy flow was developed for motion in curved ducts. A parametric study over a range of frequencies determined the ability of circular bends to transmit energy for the case of perfectly rigid walls.

  18. Twisted Vector Bundles on Pointed Nodal Curves

    Indian Academy of Sciences (India)

    Abstract. Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich's and Vistoli's twisted bundles and Gieseker vector bundles.

  19. Statistics from dynamics in curved spacetime

    International Nuclear Information System (INIS)

    Parker, L.; Wang, Y.

    1989-01-01

    We consider quantum fields of spin 0, 1/2, 1, 3/2, and 2 with a nonzero mass in curved spacetime. We show that the dynamical Bogolubov transformations associated with gravitationally induced particle creation imply the connection between spin and statistics: By embedding two flat regions in a curved spacetime, we find that only when one imposes Bose-Einstein statistics for an integer-spin field and Fermi-Dirac statistics for a half-integer-spin field in the first flat region is the same type of statistics propagated from the first to the second flat region. This derivation of the flat-spacetime spin-statistics theorem makes use of curved-spacetime dynamics and does not reduce to any proof given in flat spacetime. We also show in the same manner that parastatistics, up to the fourth order, are consistent with the dynamical evolution of curved spacetime

  20. RMS fatigue curves for random vibrations

    International Nuclear Information System (INIS)

    Brenneman, B.; Talley, J.G.

    1984-01-01

    Fatigue usage factors for deterministic or constant amplitude vibration stresses may be calculated with well known procedures and fatigue curves given in the ASME Boiler and Pressure Vessel Code. However, some phenomena produce nondeterministic cyclic stresses which can only be described and analyzed with statistical concepts and methods. Such stresses may be caused by turbulent fluid flow over a structure. Previous methods for solving this statistical fatigue problem are often difficult to use and may yield inaccurate results. Two such methods examined herein are Crandall's method and the ''3sigma'' method. The objective of this paper is to provide a method for creating ''RMS fatigue curves'' which accurately incorporate the requisite statistical information. These curves are given and may be used by analysts with the same ease and in the same manner as the ASME fatigue curves

  1. Neutron cross sections: Book of curves

    International Nuclear Information System (INIS)

    McLane, V.; Dunford, C.L.; Rose, P.F.

    1988-01-01

    Neuton Cross Sections: Book of Curves represents the fourth edition of what was previously known as BNL-325, Neutron Cross Sections, Volume 2, CURVES. Data is presented only for (i.e., intergrated) reaction cross sections (and related fission parameters) as a function of incident-neutron energy for the energy range 0.01 eV to 200 MeV. For the first time, isometric state production cross sections have been included. 11 refs., 4 figs

  2. Constructing elliptic curves from Galois representations

    OpenAIRE

    Snowden, Andrew; Tsimerman, Jacob

    2017-01-01

    Given a non-isotrivial elliptic curve over an arithmetic surface, one obtains a lisse $\\ell$-adic sheaf of rank two over the surface. This lisse sheaf has a number of straightforward properties: cyclotomic determinant, finite ramification, rational traces of Frobenius, and somewhere not potentially good reduction. We prove that any lisse sheaf of rank two possessing these properties comes from an elliptic curve.

  3. Curved twistor spaces and H-space

    International Nuclear Information System (INIS)

    Tod, K.P.

    1980-01-01

    The curved twistor space construction of Penrose for anti-self-dual solutions to the Einstein vacuum equations is described. Curved twistor spaces are defined and it is shown with the aid of an example how to obtain them by deforming the complex structure of regions of flat twistor space. The connection of this procedure with Newman's H-space construction via asymptotic twistor space is outlined. (Auth.)

  4. Potential Energy Curve of N2 Revisited

    Czech Academy of Sciences Publication Activity Database

    Špirko, Vladimír; Xiangzhu, L.; Paldus, J.

    2011-01-01

    Roč. 76, č. 4 (2011), s. 327-341 ISSN 0010-0765 R&D Projects: GA MŠk LC512; GA ČR GAP208/11/0436 Institutional research plan: CEZ:AV0Z40550506 Keywords : reduced multireference coupled-cluster method * reduced potential curve method * nitrogen molecule potential energy curves Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.283, year: 2011

  5. Curvature Entropy for Curved Profile Generation

    OpenAIRE

    Ujiie, Yoshiki; Kato, Takeo; Sato, Koichiro; Matsuoka, Yoshiyuki

    2012-01-01

    In a curved surface design, the overall shape features that emerge from combinations of shape elements are important. However, controlling the features of the overall shape in curved profiles is difficult using conventional microscopic shape information such as dimension. Herein two types of macroscopic shape information, curvature entropy and quadrature curvature entropy, quantitatively represent the features of the overall shape. The curvature entropy is calculated by the curvature distribu...

  6. Anomalies in curved spacetime at finite temperature

    International Nuclear Information System (INIS)

    Boschi-Filho, H.; Natividade, C.P.

    1993-01-01

    We discuss the problem of the breakdown of conformal and gauge symmetries at finite temperature in curved spacetime background, when the changes in the background are gradual. We obtain the expressions for the Seeley's coefficients and the heat kernel expansion in this regime. As applications, we consider the self-interacting lambda phi''4 and chiral Schwinger models in curved backgrounds at finite temperature. (Author) 9 refs

  7. Learning curves in health professions education.

    Science.gov (United States)

    Pusic, Martin V; Boutis, Kathy; Hatala, Rose; Cook, David A

    2015-08-01

    Learning curves, which graphically show the relationship between learning effort and achievement, are common in published education research but are not often used in day-to-day educational activities. The purpose of this article is to describe the generation and analysis of learning curves and their applicability to health professions education. The authors argue that the time is right for a closer look at using learning curves-given their desirable properties-to inform both self-directed instruction by individuals and education management by instructors.A typical learning curve is made up of a measure of learning (y-axis), a measure of effort (x-axis), and a mathematical linking function. At the individual level, learning curves make manifest a single person's progress towards competence including his/her rate of learning, the inflection point where learning becomes more effortful, and the remaining distance to mastery attainment. At the group level, overlaid learning curves show the full variation of a group of learners' paths through a given learning domain. Specifically, they make overt the difference between time-based and competency-based approaches to instruction. Additionally, instructors can use learning curve information to more accurately target educational resources to those who most require them.The learning curve approach requires a fine-grained collection of data that will not be possible in all educational settings; however, the increased use of an assessment paradigm that explicitly includes effort and its link to individual achievement could result in increased learner engagement and more effective instructional design.

  8. Environmental bias and elastic curves on surfaces

    International Nuclear Information System (INIS)

    Guven, Jemal; María Valencia, Dulce; Vázquez-Montejo, Pablo

    2014-01-01

    The behavior of an elastic curve bound to a surface will reflect the geometry of its environment. This may occur in an obvious way: the curve may deform freely along directions tangent to the surface, but not along the surface normal. However, even if the energy itself is symmetric in the curve's geodesic and normal curvatures, which control these modes, very distinct roles are played by the two. If the elastic curve binds preferentially on one side, or is itself assembled on the surface, not only would one expect the bending moduli associated with the two modes to differ, binding along specific directions, reflected in spontaneous values of these curvatures, may be favored. The shape equations describing the equilibrium states of a surface curve described by an elastic energy accommodating environmental factors will be identified by adapting the method of Lagrange multipliers to the Darboux frame associated with the curve. The forces transmitted to the surface along the surface normal will be determined. Features associated with a number of different energies, both of physical relevance and of mathematical interest, are described. The conservation laws associated with trajectories on surface geometries exhibiting continuous symmetries are also examined. (paper)

  9. Geometric invariant theory for polarized curves

    CERN Document Server

    Bini, Gilberto; Melo, Margarida; Viviani, Filippo

    2014-01-01

    We investigate GIT quotients of polarized curves. More specifically, we study the GIT problem for the Hilbert and Chow schemes of curves of degree d and genus g in a projective space of dimension d-g, as d decreases with respect to g. We prove that the first three values of d at which the GIT quotients change are given by d=a(2g-2) where a=2, 3.5, 4. We show that, for a>4, L. Caporaso's results hold true for both Hilbert and Chow semistability. If 3.5curves. If 2curves. We also analyze in detail the critical values a=3.5 and a=4, where the Hilbert semistable locus is strictly smaller than the Chow semistable locus. As an application, we obtain three compactications of the universal Jacobian over the moduli space of stable curves, weakly-pseudo-stable curves and pseu...

  10. Global experience curves for wind farms

    International Nuclear Information System (INIS)

    Junginger, M.; Faaij, A.; Turkenburg, W.C.

    2005-01-01

    In order to forecast the technological development and cost of wind turbines and the production costs of wind electricity, frequent use is made of the so-called experience curve concept. Experience curves of wind turbines are generally based on data describing the development of national markets, which cause a number of problems when applied for global assessments. To analyze global wind energy price development more adequately, we compose a global experience curve. First, underlying factors for past and potential future price reductions of wind turbines are analyzed. Also possible implications and pitfalls when applying the experience curve methodology are assessed. Second, we present and discuss a new approach of establishing a global experience curve and thus a global progress ratio for the investment cost of wind farms. Results show that global progress ratios for wind farms may lie between 77% and 85% (with an average of 81%), which is significantly more optimistic than progress ratios applied in most current scenario studies and integrated assessment models. While the findings are based on a limited amount of data, they may indicate faster price reduction opportunities than so far assumed. With this global experience curve we aim to improve the reliability of describing the speed with which global costs of wind power may decline

  11. Stenting for curved lesions using a novel curved balloon: Preliminary experimental study.

    Science.gov (United States)

    Tomita, Hideshi; Higaki, Takashi; Kobayashi, Toshiki; Fujii, Takanari; Fujimoto, Kazuto

    2015-08-01

    Stenting may be a compelling approach to dilating curved lesions in congenital heart diseases. However, balloon-expandable stents, which are commonly used for congenital heart diseases, are usually deployed in a straight orientation. In this study, we evaluated the effect of stenting with a novel curved balloon considered to provide better conformability to the curved-angled lesion. In vitro experiments: A Palmaz Genesis(®) stent (Johnson & Johnson, Cordis Co, Bridgewater, NJ, USA) mounted on the Goku(®) curve (Tokai Medical Co. Nagoya, Japan) was dilated in vitro to observe directly the behavior of the stent and balloon assembly during expansion. Animal experiment: A short Express(®) Vascular SD (Boston Scientific Co, Marlborough, MA, USA) stent and a long Express(®) Vascular LD stent (Boston Scientific) mounted on the curved balloon were deployed in the curved vessel of a pig to observe the effect of stenting in vivo. In vitro experiments: Although the stent was dilated in a curved fashion, stent and balloon assembly also rotated conjointly during expansion of its curved portion. In the primary stenting of the short stent, the stent was dilated with rotation of the curved portion. The excised stent conformed to the curved vessel. As the long stent could not be negotiated across the mid-portion with the balloon in expansion when it started curving, the mid-portion of the stent failed to expand fully. Furthermore, the balloon, which became entangled with the stent strut, could not be retrieved even after complete deflation. This novel curved balloon catheter might be used for implantation of the short stent in a curved lesion; however, it should not be used for primary stenting of the long stent. Post-dilation to conform the stent to the angled vessel would be safer than primary stenting irrespective of stent length. Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  12. Development of the curve of Spee.

    Science.gov (United States)

    Marshall, Steven D; Caspersen, Matthew; Hardinger, Rachel R; Franciscus, Robert G; Aquilino, Steven A; Southard, Thomas E

    2008-09-01

    Ferdinand Graf von Spee is credited with characterizing human occlusal curvature viewed in the sagittal plane. This naturally occurring phenomenon has clinical importance in orthodontics and restorative dentistry, yet we have little understanding of when, how, or why it develops. The purpose of this study was to expand our understanding by examining the development of the curve of Spee longitudinally in a sample of untreated subjects with normal occlusion from the deciduous dentition to adulthood. Records of 16 male and 17 female subjects from the Iowa Facial Growth Study were selected and examined. The depth of the curve of Spee was measured on their study models at 7 time points from ages 4 (deciduous dentition) to 26 (adult dentition) years. The Wilcoxon signed rank test was used to compare changes in the curve of Spee depth between time points. For each subject, the relative eruption of the mandibular teeth was measured from corresponding cephalometric radiographs, and its contribution to the developing curve of Spee was ascertained. In the deciduous dentition, the curve of Spee is minimal. At mean ages of 4.05 and 5.27 years, the average curve of Spee depths are 0.24 and 0.25 mm, respectively. With change to the transitional dentition, corresponding to the eruption of the mandibular permanent first molars and central incisors (mean age, 6.91 years), the curve of Spee depth increases significantly (P < 0.0001) to a mean maximum depth of 1.32 mm. The curve of Spee then remains essentially unchanged until eruption of the second molars (mean age, 12.38 years), when the depth increases (P < 0.0001) to a mean maximum depth of 2.17 mm. In the adolescent dentition (mean age, 16.21 years), the depth decreases slightly (P = 0.0009) to a mean maximum depth of 1.98 mm, and, in the adult dentition (mean age 26.98 years), the curve remains unchanged (P = 0.66), with a mean maximum depth of 2.02 mm. No significant differences in curve of Spee development were found between

  13. Prevalence, Risk Factors, and Outcome of Myocardial Infarction with Angiographically Normal and Near-Normal Coronary Arteries: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Samad Ghaffari

    2016-12-01

    Full Text Available Context: Coronary artery diseases are mostly detected using angiographic methods demonstrating arteries status. Nevertheless, Myocardial Infarction (MI may occur in the presence of angiographically normal coronary arteries. Therefore, this study aimed to investigate the prevalence of MI with normal angiography and its possible etiologies in a systematic review. Evidence Acquisition: In this meta-analysis, the required data were collected from PubMed, Science Direct, Google Scholar, Scopus, Magiran, Scientific Information Database, and Medlib databases using the following keywords: “coronary angiograph”, “normal coronary arteries”, “near-normal coronary arteries”, “heart diseases”, “coronary artery disease”, “coronary disease”, “cardiac troponin I”, “Myocardial infarction”, “risk factor”, “prevalence”, “outcome”, and their Persian equivalents. Then, Comprehensive Meta-Analysis software, version 2 using randomized model was employed to determine the prevalence of each complication and perform the meta-analysis. P values less than 0.05 were considered to be statistically significant. Results: Totally, 20 studies including 139957 patients were entered into the analysis. The patients’ mean age was 47.62 ± 6.63 years and 64.4% of the patients were male. The prevalence of MI with normal or near-normal coronary arteries was 3.5% (CI = 95%, min = 2.2%, and max = 5.7%. Additionally, smoking and family history of cardiovascular diseases were the most important risk factors. The results showed no significant difference between MIs with normal angiography and 1- or 2-vessel involvement regarding the frequency of major adverse cardiac events (5.4% vs. 7.3%, P = 0.32. However, a significant difference was found between the patients with normal angiography and those with 3-vessel involvement in this regard (5.4% vs. 20.2%, P < 0.001. Conclusions: Although angiographic studies are required to assess the underlying

  14. F(α) curves: Experimental results

    International Nuclear Information System (INIS)

    Glazier, J.A.; Gunaratne, G.; Libchaber, A.

    1988-01-01

    We study the transition to chaos at the golden and silver means for forced Rayleigh-Benard (RB) convection in mercury. We present f(α) curves below, at, and above the transition, and provide comparisons to the curves calculated for the one-dimensional circle map. We find good agreement at both the golden and silver means. This confirms our earlier observation that for low amplitude forcing, forced RB convection is well described by the one-dimensional circle map and indicates that the f(α) curve is a good measure of the approach to criticality. For selected subcritical experimental data sets we calculate the degree of subcriticality. We also present both experimental and calculated results for f(α) in the presence of a third frequency. Again we obtain agreement: The presence of random noise or a third frequency narrows the right-hand (negative q) side of the f(α) curve. Subcriticality results in symmetrically narrowed curves. We can also distinguish these cases by examining the power spectra and Poincare sections of the time series

  15. Multiwavelength light curve parameters of Cepheid variables

    Directory of Open Access Journals (Sweden)

    Bhardwaj Anupam

    2017-01-01

    Full Text Available We present a comparative analysis of theoretical and observed light curves of Cepheid variables using Fourier decomposition. The theoretical light curves at multiple wavelengths are generated using stellar pulsation models for chemical compositions representative of Cepheids in the Galaxy and Magellanic Clouds. The observed light curves at optical (VI, near-infrared (JHKs and mid-infrared (3.6 & 4.5-μm bands are compiled from the literature. We discuss the variation of light curve parameters as a function of period, wavelength and metallicity. Theoretical and observed Fourier amplitude parameters decrease with increase in wavelength while the phase parameters increase with wavelength. We find that theoretical amplitude parameters obtained using canonical mass-luminosity levels exhibit a greater offset with respect to observations when compared to non-canonical relations. We also discuss the impact of variation in convective efficiency on the light curve structure of Cepheid variables. The increase in mixing length parameter results in a zero-point offset in bolometric mean magnitudes and reduces the systematic large difference in theoretical amplitudes with respect to observations.

  16. Incorporating experience curves in appliance standards analysis

    International Nuclear Information System (INIS)

    Desroches, Louis-Benoit; Garbesi, Karina; Kantner, Colleen; Van Buskirk, Robert; Yang, Hung-Chia

    2013-01-01

    There exists considerable evidence that manufacturing costs and consumer prices of residential appliances have decreased in real terms over the last several decades. This phenomenon is generally attributable to manufacturing efficiency gained with cumulative experience producing a certain good, and is modeled by an empirical experience curve. The technical analyses conducted in support of U.S. energy conservation standards for residential appliances and commercial equipment have, until recently, assumed that manufacturing costs and retail prices remain constant during the projected 30-year analysis period. This assumption does not reflect real market price dynamics. Using price data from the Bureau of Labor Statistics, we present U.S. experience curves for room air conditioners, clothes dryers, central air conditioners, furnaces, and refrigerators and freezers. These experience curves were incorporated into recent energy conservation standards analyses for these products. Including experience curves increases the national consumer net present value of potential standard levels. In some cases a potential standard level exhibits a net benefit when considering experience, whereas without experience it exhibits a net cost. These results highlight the importance of modeling more representative market prices. - Highlights: ► Past appliance standards analyses have assumed constant equipment prices. ► There is considerable evidence of consistent real price declines. ► We incorporate experience curves for several large appliances into the analysis. ► The revised analyses demonstrate larger net present values of potential standards. ► The results imply that past standards analyses may have undervalued benefits.

  17. Comparison of power curve monitoring methods

    Directory of Open Access Journals (Sweden)

    Cambron Philippe

    2017-01-01

    Full Text Available Performance monitoring is an important aspect of operating wind farms. This can be done through the power curve monitoring (PCM of wind turbines (WT. In the past years, important work has been conducted on PCM. Various methodologies have been proposed, each one with interesting results. However, it is difficult to compare these methods because they have been developed using their respective data sets. The objective of this actual work is to compare some of the proposed PCM methods using common data sets. The metric used to compare the PCM methods is the time needed to detect a change in the power curve. Two power curve models will be covered to establish the effect the model type has on the monitoring outcomes. Each model was tested with two control charts. Other methodologies and metrics proposed in the literature for power curve monitoring such as areas under the power curve and the use of statistical copulas have also been covered. Results demonstrate that model-based PCM methods are more reliable at the detecting a performance change than other methodologies and that the effectiveness of the control chart depends on the types of shift observed.

  18. Asymptotic scalings of developing curved pipe flow

    Science.gov (United States)

    Ault, Jesse; Chen, Kevin; Stone, Howard

    2015-11-01

    Asymptotic velocity and pressure scalings are identified for the developing curved pipe flow problem in the limit of small pipe curvature and high Reynolds numbers. The continuity and Navier-Stokes equations in toroidal coordinates are linearized about Dean's analytical curved pipe flow solution (Dean 1927). Applying appropriate scaling arguments to the perturbation pressure and velocity components and taking the limits of small curvature and large Reynolds number yields a set of governing equations and boundary conditions for the perturbations, independent of any Reynolds number and pipe curvature dependence. Direct numerical simulations are used to confirm these scaling arguments. Fully developed straight pipe flow is simulated entering a curved pipe section for a range of Reynolds numbers and pipe-to-curvature radius ratios. The maximum values of the axial and secondary velocity perturbation components along with the maximum value of the pressure perturbation are plotted along the curved pipe section. The results collapse when the scaling arguments are applied. The numerically solved decay of the velocity perturbation is also used to determine the entrance/development lengths for the curved pipe flows, which are shown to scale linearly with the Reynolds number.

  19. Critical Factors for Inducing Curved Somatosensory Saccades

    Directory of Open Access Journals (Sweden)

    Tamami Nakano

    2011-10-01

    Full Text Available We are able to make a saccade toward a tactile stimuli to one hand, but trajectories of many saccades curved markedly when the arms were crossed (Groh & Sparks, 2006. However, it remains unknown why some curved and others did not. We therefore examined critical factors for inducing the curved somatosensory saccades. Participants made a saccade as soon as possible from a central fixation point toward a tactile stimulus delivered to one of the two hands, and switched between arms-crossed and arms-uncrossed postures every 6 trials. Trajectories were generally straight when the arms were uncrossed, but all participants made curved saccades when the arms were crossed (12–64%. We found that the probability of curved saccades depended critically on the onset latency: the probability was less than 5% when the latency was larger than 250 ms, but the probability increased up to 70–80% when the onset latency was 160 ms. This relationship was shared across participants. The results suggest that a touch in the arms-crossed posture was always mapped to the wrong hand in the initial phase up to 160 ms, and then remapped to the correct hand during the next 100 ms by some fundamental neural mechanisms shared across participants.

  20. Metallic Limus-Eluting Stents Abluminally Coated with Biodegradable Polymers: Angiographic and Clinical Comparison of a Novel Ultra-Thin Sirolimus Stent Versus Biolimus Stent in the DESTINY Randomized Trial.

    Science.gov (United States)

    Lemos, Pedro A; Abizaid, Alexandre A C; Meireles, George C; Sarmento-Leite, Rogério; Prudente, Mauricio; Cantarelli, Marcelo; Dourado, Adriano D; Mariani, Jose; Perin, Marco A; Costantini, Costantino; Costa, Ricardo A; Costa, José Ribamar; Chamie, Daniel; Campos, Carlos A; Ribeiro, Expedito

    2015-12-01

    To evaluate the outcomes of patients treated with a new drug-eluting stent formulation with low doses of sirolimus, built in an ultra-thin-strut platform coated with biodegradable abluminal coating. This study is a randomized trial that tested the main hypothesis that the angiographic late lumen loss of the novel sirolimus-eluting stent is noninferior compared with commercially available biolimus-eluting stent. A final study population comprising 170 patients with one or two de novo lesions was randomized in the ratio 2:1 for sirolimus-eluting stent or biolimus-eluting stent, respectively. The primary endpoint was 9-month angiographic in-stent late lumen loss. Adverse clinical events were prospectively collected for 1 year. After 9 months, the novel sirolimus-eluting stent was shown noninferior compared with the biolimus stent for the primary endpoint (angiographic in-stent late lumen loss: 0.20 ± 0.29 mm vs. 0.15 ± 0.20 mm, respectively; P value for noninferiority <0.001). The 1-year incidence of death, myocardial infarction, repeat revascularization, and stent thrombosis remained low and not significantly different between the groups. The present randomized trial demonstrates that the tested novel sirolimus-eluting stent was angiographically noninferior in comparison with a last-generation biolimus-eluting stent. © 2015 John Wiley & Sons Ltd.

  1. Surface growth kinematics via local curve evolution

    KAUST Repository

    Moulton, Derek E.

    2012-11-18

    A mathematical framework is developed to model the kinematics of surface growth for objects that can be generated by evolving a curve in space, such as seashells and horns. Growth is dictated by a growth velocity vector field defined at every point on a generating curve. A local orthonormal basis is attached to each point of the generating curve and the velocity field is given in terms of the local coordinate directions, leading to a fully local and elegant mathematical structure. Several examples of increasing complexity are provided, and we demonstrate how biologically relevant structures such as logarithmic shells and horns emerge as analytical solutions of the kinematics equations with a small number of parameters that can be linked to the underlying growth process. Direct access to cell tracks and local orientation enables for connections to be made to the underlying growth process. © 2012 Springer-Verlag Berlin Heidelberg.

  2. Asymmetry dependence of the nuclear caloric curve

    International Nuclear Information System (INIS)

    McIntosh, A.B.; Bonasera, A.; Cammarata, P.; Hagel, K.; Heilborn, L.; Kohley, Z.; Mabiala, J.; May, L.W.; Marini, P.; Raphelt, A.; Souliotis, G.A.; Wuenschel, S.; Zarrella, A.; Yennello, S.J.

    2013-01-01

    A basic feature of the nuclear equation of state is not yet understood: the dependence of the nuclear caloric curve on the neutron–proton asymmetry. Predictions of theoretical models differ on the magnitude and even the sign of this dependence. In this work, the nuclear caloric curve is examined for fully reconstructed quasi-projectiles around mass A=50. The caloric curve extracted with the momentum quadrupole fluctuation thermometer shows that the temperature varies linearly with quasi-projectile asymmetry (N−Z)/A . An increase in asymmetry of 0.15 units corresponds to a decrease in temperature on the order of 1 MeV. These results also highlight the importance of a full quasi-projectile reconstruction in the study of thermodynamic properties of hot nuclei

  3. The genus curve of the Abell clusters

    Science.gov (United States)

    Rhoads, James E.; Gott, J. Richard, III; Postman, Marc

    1994-01-01

    We study the topology of large-scale structure through a genus curve measurement of the recent Abell catalog redshift survey of Postman, Huchra, and Geller (1992). The structure is found to be spongelike near median density and to exhibit isolated superclusters and voids at high and low densities, respectively. The genus curve shows a slight shift toward 'meatball' topology, but remains consistent with the hypothesis of Gaussian random phase initial conditions. The amplitude of the genus curve corresponds to a power-law spectrum with index n = 0.21-0.47+0.43 on scales of 48/h Mpc or to a cold dark matter power spectrum with omega h = 0.36-0.17+0.46.

  4. Differential geometry of curves and surfaces

    CERN Document Server

    Banchoff, Thomas F

    2010-01-01

    Students and professors of an undergraduate course in differential geometry will appreciate the clear exposition and comprehensive exercises in this book that focuses on the geometric properties of curves and surfaces, one- and two-dimensional objects in Euclidean space. The problems generally relate to questions of local properties (the properties observed at a point on the curve or surface) or global properties (the properties of the object as a whole). Some of the more interesting theorems explore relationships between local and global properties. A special feature is the availability of accompanying online interactive java applets coordinated with each section. The applets allow students to investigate and manipulate curves and surfaces to develop intuition and to help analyze geometric phenomena.

  5. Experimental simulation of closed timelike curves.

    Science.gov (United States)

    Ringbauer, Martin; Broome, Matthew A; Myers, Casey R; White, Andrew G; Ralph, Timothy C

    2014-06-19

    Closed timelike curves are among the most controversial features of modern physics. As legitimate solutions to Einstein's field equations, they allow for time travel, which instinctively seems paradoxical. However, in the quantum regime these paradoxes can be resolved, leaving closed timelike curves consistent with relativity. The study of these systems therefore provides valuable insight into nonlinearities and the emergence of causal structures in quantum mechanics--essential for any formulation of a quantum theory of gravity. Here we experimentally simulate the nonlinear behaviour of a qubit interacting unitarily with an older version of itself, addressing some of the fascinating effects that arise in systems traversing a closed timelike curve. These include perfect discrimination of non-orthogonal states and, most intriguingly, the ability to distinguish nominally equivalent ways of preparing pure quantum states. Finally, we examine the dependence of these effects on the initial qubit state, the form of the unitary interaction and the influence of decoherence.

  6. Design fatigue curve for Hastelloy-X

    International Nuclear Information System (INIS)

    Nishiguchi, Isoharu; Muto, Yasushi; Tsuji, Hirokazu

    1983-12-01

    In the design of components intended for elevated temperature service as the experimental Very High-Temperature gas-cooled Reactor (VHTR), it is essential to prevent fatigue failure and creep-fatigue failure. The evaluation method which uses design fatigue curves is adopted in the design rules. This report discussed several aspects of these design fatigue curves for Hastelloy-X (-XR) which is considered for use as a heat-resistant alloy in the VHTR. Examination of fatigue data gathered by a literature search including unpublished data showed that Brinkman's equation is suitable for the design curve of Hastelloy-X (-XR), where total strain range Δ epsilon sub(t) is used as independent variable and fatigue life Nsub(f) is transformed into log(log Nsub(f)). (author)

  7. The genus curve of the Abell clusters

    Science.gov (United States)

    Rhoads, James E.; Gott, J. Richard, III; Postman, Marc

    1994-01-01

    We study the topology of large-scale structure through a genus curve measurement of the recent Abell catalog redshift survey of Postman, Huchra, and Geller (1992). The structure is found to be spongelike near median density and to exhibit isolated superclusters and voids at high and low densities, respectively. The genus curve shows a slight shift toward 'meatball' topology, but remains consistent with the hypothesis of Gaussian random phase initial conditions. The amplitude of the genus curve corresponds to a power-law spectrum with index n = 0.21(sub -0.47 sup +0.43) on scales of 48/h Mpc or to a cold dark matter power spectrum with omega h = 0.36(sub -0.17 sup +0.46).

  8. Deep-learnt classification of light curves

    DEFF Research Database (Denmark)

    Mahabal, Ashish; Gieseke, Fabian; Pai, Akshay Sadananda Uppinakudru

    2017-01-01

    is to derive statistical features from the time series and to use machine learning methods, generally supervised, to separate objects into a few of the standard classes. In this work, we transform the time series to two-dimensional light curve representations in order to classify them using modern deep......Astronomy light curves are sparse, gappy, and heteroscedastic. As a result standard time series methods regularly used for financial and similar datasets are of little help and astronomers are usually left to their own instruments and techniques to classify light curves. A common approach...... learning techniques. In particular, we show that convolutional neural networks based classifiers work well for broad characterization and classification. We use labeled datasets of periodic variables from CRTS survey and show how this opens doors for a quick classification of diverse classes with several...

  9. Energy efficiency and load curve impacts

    International Nuclear Information System (INIS)

    Feilberg, Nicolai

    2002-01-01

    One of SINTEF Energy Research's European RTD projects is the two-year EFFLOCOM (Energy EFFiciency and LOad curve impacts of COMmercial development in competitive markets). This project will determine the end-user response of different market-related services offered in deregulated power markets. The project will investigate the possibility of influencing load curves by using different price signals and two-way communications via Internet. The partners are from Denmark. Finland, England, France and Norway. SINTEF Energy Research is in charge of the project management. During the project, the changes in load curves will he studied in the in the participating countries before and after deregulation. Specific issues are the use of ICT, time- and situation-dependent tariffs and smart-house technology. The project will consist of 5 work packages that will give recommendations about new methods, guidelines and tools to promote effective use of energy in the partner countries. The total budget is EUR 692 000. (author)

  10. Trend curve data development and testing

    International Nuclear Information System (INIS)

    McElroy, W.N.; Gold, R.; Simons, R.L.; Roberts, J.H.

    1986-01-01

    Existing trend curves do not account for previous and more recently observed test and power reactor flux-level, thermal neutron and γ-ray field-induced effects. Any agreement between measured data and trend curve predictions that does not adequately represent the important neutron environmental and temperature effects as well as the microstructural damage processes, therefore, could be fortuitous. Empirically derived end-of-life (EOL) and life-extension-range (LER) trend curves are presented and discussed in this paper for high temperature [∼288 0 C (550 0 F)] irradiation of two weld, two plate, and two forging pressure vessel (PV) steels and low-temperature [∼60 0 C (140 0 F)] irradiation of one support structure-type steel

  11. Minimal families of curves on surfaces

    KAUST Repository

    Lubbes, Niels

    2014-11-01

    A minimal family of curves on an embedded surface is defined as a 1-dimensional family of rational curves of minimal degree, which cover the surface. We classify such minimal families using constructive methods. This allows us to compute the minimal families of a given surface.The classification of minimal families of curves can be reduced to the classification of minimal families which cover weak Del Pezzo surfaces. We classify the minimal families of weak Del Pezzo surfaces and present a table with the number of minimal families of each weak Del Pezzo surface up to Weyl equivalence.As an application of this classification we generalize some results of Schicho. We classify algebraic surfaces that carry a family of conics. We determine the minimal lexicographic degree for the parametrization of a surface that carries at least 2 minimal families. © 2014 Elsevier B.V.

  12. Energy and GHG abatement cost curves

    Energy Technology Data Exchange (ETDEWEB)

    Alvarenga, Rafael [BHP Billiton Base Metals (Australia)

    2010-07-01

    Global warming due to various reasons but especially to emission of green house gases (GHGs) has become a cause for serious concern. This paper discusses the steps taken by BHP Billiton to reduce energy consumption and GHG emissions using cost curves. According to forecasts, global warming is expected to impact Chile badly and the rise in temperature could be between 1 and more than 5 degrees Celsius. Mining in Chile consumes a lot of energy, particularly electricity. Total energy and electricity consumption in 2007 was 13 and 36 % respectively. BHP base metals developed a set of abatement cost curves for energy and GHG in Chile and these are shown in figures. The methodology for the curves consisted of consultant visits to each mine operation. The study also includes mass energy balance and feasibility maps. The paper concludes that it is important to evaluate the potential for reducing emissions and energy and their associated costs.

  13. POSSIBLE RECESSION CURVE APPLICATIONS FOR RETENTION EVALUATION

    Directory of Open Access Journals (Sweden)

    Daniel Liberacki

    2015-11-01

    Full Text Available The objective of the article was to present possible applications of recession flow curve in a small lowland watershed retention discharge size evaluation. The examined woodland micro catchment area of 0.52 sq km is located in Puszcza Zielonka in central Wielkopolska. The Hutka catchment is typically woody with high retention abilities. The catchment of the Hutka watercourse is forested in 89%, the other 11% is covered by swamps and wasteland. The predominant sites are fresh mixed coniferous forest (BMśw, fresh coniferous forest (Bśw and alder carr forest (Ol. Landscape in catchment is characterized by a large number of interior depressions, filled partly with rainwater or peatbogs, with poorly developed natural drainage. The watercourses do not exceed 1 km in length, the mean width is approx. 0.5 m, while mean depth ranges from 0.2 to 0.3 m. During hydrological research conducted in 1997/1998–1999/2000, 35 major (characteristic raised water stages were observed in Hutka after substantial precipitation. The recession curve dating from 18–24 September 2000 has the α and n rates nearest to average. Comparing the model curve and the curve created by observing watercourse flow, one can notice their resemblance and that they have similar ordinate values as well as shape. In the case of other recession curves, the maximum differences of ordinate values are also about 0.1–0.2 l/s/km2. The measuured α and n rates do not reveal any regularities. There are no significant statistical Horton model parameter (for recession flow curves dependencies between α and n and e.g. initial flows (Qo or the whole period of high water waves (Qp. Consequently, calculated relation between these parameters is only an approximation for the general evaluation of the retention discharge in the catchment area towards retention with flow function.

  14. Fractal properties of critical invariant curves

    International Nuclear Information System (INIS)

    Hunt, B.R.; Yorke, J.A.; Khanin, K.M.; Sinai, Y.G.

    1996-01-01

    We examine the dimension of the invariant measure for some singular circle homeomorphisms for a variety of rotation numbers, through both the thermodynamic formalism and numerical computation. The maps we consider include those induced by the action of the standard map on an invariant curve at the critical parameter value beyond which the curve is destroyed. Our results indicate that the dimension is universal for a given type of singularity and rotation number, and that among all rotation numbers, the golden mean produces the largest dimension

  15. Trend curve data development and testing

    International Nuclear Information System (INIS)

    McElroy, W.N.; Gold, R.; Simons, R.L.; Roberts, J.H.

    1986-08-01

    Existing trend curves do not account for previous and more recently observed test and power reactor flux-level, thermal neutron and gamma-ray field-induced effects. Any agreement between measured data and trend curve predictions that does not adequately represent the important neutron environmental and temperature effects as well as the microstructural damage processes, therefore, could be fortuitous. Two principal questions asked concerning the metallurgical condition of the pressure vessel and its support structures are: What are the controlling variables; and What effects do they have on changing the metallurgical properties of the vessel and its support structures throughout their lifetimes

  16. Linear Titration Curves of Acids and Bases.

    Science.gov (United States)

    Joseph, N R

    1959-05-29

    The Henderson-Hasselbalch equation, by a simple transformation, becomes pH - pK = pA - pB, where pA and pB are the negative logarithms of acid and base concentrations. Sigmoid titration curves then reduce to straight lines; titration curves of polyelectrolytes, to families of straight lines. The method is applied to the titration of the dipeptide glycyl aminotricarballylic acid, with four titrable groups. Results are expressed as Cartesian and d'Ocagne nomograms. The latter is of a general form applicable to polyelectrolytes of any degree of complexity.

  17. From Curve Fitting to Machine Learning

    CERN Document Server

    Zielesny, Achim

    2011-01-01

    The analysis of experimental data is at heart of science from its beginnings. But it was the advent of digital computers that allowed the execution of highly non-linear and increasingly complex data analysis procedures - methods that were completely unfeasible before. Non-linear curve fitting, clustering and machine learning belong to these modern techniques which are a further step towards computational intelligence. The goal of this book is to provide an interactive and illustrative guide to these topics. It concentrates on the road from two dimensional curve fitting to multidimensional clus

  18. Phonon dispersion curves for CsCN

    International Nuclear Information System (INIS)

    Gaur, N.K.; Singh, Preeti; Rini, E.G.; Galgale, Jyostna; Singh, R.K.

    2004-01-01

    The motivation for the present work was gained from the recent publication on phonon dispersion curves (PDCs) of CsCN from the neutron scattering technique. We have applied the extended three-body force shell model (ETSM) by incorporating the effect of coupling between the translation modes and the orientation of cyanide molecules for the description of phonon dispersion curves of CsCN between the temperatures 195 and 295 K. Our results on PDCs in symmetric direction are in good agreement with the experimental data measured with inelastic neutron scattering technique. (author)

  19. Bound states in curved quantum waveguides

    International Nuclear Information System (INIS)

    Exner, P.; Seba, P.

    1987-01-01

    We study free quantum particle living on a curved planar strip Ω of a fixed width d with Dirichlet boundary conditions. It can serve as a model for electrons in thin films on a cylindrical-type substrate, or in a curved quantum wire. Assuming that the boundary of Ω is infinitely smooth and its curvature decays fast enough at infinity, we prove that a bound state with energy below the first transversal mode exists for all sufficiently small d. A lower bound on the critical width is obtained using the Birman-Schwinger technique. (orig.)

  20. Strange Curves, Counting Rabbits, & Other Mathematical Explorations

    CERN Document Server

    Ball, Keith

    2011-01-01

    How does mathematics enable us to send pictures from space back to Earth? Where does the bell-shaped curve come from? Why do you need only 23 people in a room for a 50/50 chance of two of them sharing the same birthday? In Strange Curves, Counting Rabbits, and Other Mathematical Explorations, Keith Ball highlights how ideas, mostly from pure math, can answer these questions and many more. Drawing on areas of mathematics from probability theory, number theory, and geometry, he explores a wide range of concepts, some more light-hearted, others central to the development of the field and used dai